Periodontics Periodontics

f/g/s

Which statement regarding an autogenous free gingival graft is true? Select all that apply.

• it can be placed to prevent further recession

• it can be used to effectively widen the attached gingiva

• it retains its own blood supply and is not dependent on the bed of recipient blood vessels

• the greatest amount of shrinkage occurs within the first 6 weeks

• it is also useful for covering nonpathologic dehiscences and fenestrations

f/g/s

Hemisection is most likely to be performed on:

• mandibular first and second premolars

• maxillary first and second molars

• maxillary canines

• mandibular molars with buccal and lingual class II or 111 furactioninvolvement s

2 copyright © 2013-2014 - Dental Decks PERIODONTICS • it can be placed to prevent further recession can _!, nj?r\ • 't De used t0 effectively widen the attached gingiva • the greatest amount of shrinkage occurs within the first 6 weeks S t !t ^V ° tA ' is a,so useful TOr covering nonpathologic dehiscences and fenestrations Autogenous free gingival grafts retain none of there own blood supply and are totally dependent on the bed of recip ient blood vessels. In some instances, it can be used to cover a root surface with a narrow denudation. The procedure yields a high de gree of successful results when used for increasing the width of the attached gingiva. The free gingival graft may be used therapeutically to widen the gingiva after recession has occurred. It may be used prophylactically to prevent recession where the band of gingiva is narrow and of a thin, delicate consistency. The free gingival graft is an autogenous graft of gingiva that is placed on a viable connective tissue bed where ini tially, buccal or labial mucosa was present. In most cases, the donor site from which the graft is taken is an edentu lous region or the palatal area. The graft epithelium undergoes degeneration after it is placed. Then it sloughs, the 'epithelium "is reconstructed in about a week by the adjacent epithelium and proliferation of surviving donor basal cells. In 2 weeks the tissue appears to have reformed, but maturation is not completed untinl 0 to 16 weeksjThe time required is proportional to the thickness of the graft. Note: The free gingival graft receives its nutrients from the vi able connective tissue bed. 'ty&tli.. The procedure may or may not yield a successful result when used to obtain root coverage; the result is not highly predictable in such cases. The graft may be used to correct localized narrow recessions or clefts but not deep, wide recessions. In these instances, the-latecally. repositioned flap (a pedicle graft) or a subepithelial connective tissue graft has a greater predictability. The free gingival graft is rarely used on the facial or lingual surfaces of mandibu lar third molars (especially facial). Miller classification system for recession: • Class I: marginal tissue recession does not extend to the mucogingival junction. There is no loss of bone or soft tissue in the interdental area. It can be narrow or wide. • Class II: marginal tissue recession extends to or beyond the mucogingival junction. There is no loss of bone or soft tissue in the interdental areas. It can be wide or narrow. • Class III: marginal tissue recession extends to or beyond the mucogingival junction. There is bone and soft tis sue loss interdentally or malpositioning of the tooth. •Class IV: marginal tissue recession extends to or beyond the mucogingival junction. There is severe bone and soft tissue loss interdentally or severe tooth malposition. In general, the prognosis for classes I and II is good to excellent; whereas for class III, only partial coverage can be expected. Class IV has a very poor prognosis.

• mandibular molars with buccal and lingual class II or III furcation involvements

Hemisection refers to the vertical sectioning of the tooth through both crown and root. Most often, the technique is utilized in a mandibular molar region where the crown is divided through the bi furcation region. One-half of the tooth is extracted if one specific root has excessive loss in os seous support and the remaining half of the molar tooth now is treated as a premolar. Note: This process has been called bkuspidization or segaration because it changes the molar into two sep arate roots. iRqot amputation refers to the separation of an individual root from the crown structure of the tooth. Burs and diamond stones are utilized to sever the crown and root prior to extraction by root tip forceps. At the completion of the root amputation, the remaining apical area of the crown and furcation region are recontoured similar to the shape of a pontic so that maximal access is provided for oral hygiene methods. Most root amputations involve the maxillary first and second molars (these teeth are commonly involved periodontal sites). Root amputations or hemisections almost always result in irreversible pulpal damage that demands endodontic therapy. Ideally, the endo is done first, which ensures patient comfort. Sometimes the decision to do a root resection cannot be made until flaps have been reflected and the periodontal status has been carefully assessed. The RCT must be delayed until after the resection. Regardless of the sequence, consultation with both an endodontist and periodontist is required to ensure both aspects of the treatment can be performed. Note: As with root resection, molars with advanced bone loss in the interproximal and interradicular zones are not good candidates for hemisection. Important: Pontic design for crown and bridge: The sanitary and ovate pontics have convex un- dersurfaces, which makes them easiest to clean. The ridge-lap and modified ridge-lap designs have concave surfaces, which are more difficult to access with dental floss. The sanitary pontic is rarely used because of its unesthetic form. The ovate pontic is the ideal pontic form. The alveolar bone must be a minimum of 2 mm from the most apical portion of the pontic. f/g/s The main goal of osseous recontouring (surgery) is:

• to cure periodontal disease

• to eliminate the existing microflora

• to eliminate periodontal pockets

• to change the existing microflora

All of the following statements regarding periodontal flaps are true EXCEPT one. Which one is the EXCEPTION!

• full-thickness periodontal flaps involve reflecting all of the soft tissue, including the periosteum, to expose the underlying bone

• the partial-thickness periodontal flap includes only the epithelium and a layer of the underlying connective tissue

• both full-thickness and partial-thickness periodontal flaps can be displaced

• flaps from the palate are considered easier to be displaced than those from any other region

• flaps should be uniformly thin and pliable

copyright © 2013-2014 - Dental Decks PERIODONTICS • eliminate periodontal pockets — to reshape the marginal bone to resemble that of the alveolar process undamaged by periodontal disease It does not cure periodontal disease. The technique is performed in combination with apicalfy positioned flaps, and the procedure eliminates periodontal pocket depth and improves tissue contour to provide a more easily maintainable environment. Before employing, osseous resection, or recontouring to treat an infrabonydefect, the therapist should consider the following alternative treatments: • Maintenance with periodic root planing Note: Osseous resection surgery should not be done until the • Bone grafts etiologic factors that resulted in the formation of the osseous • Reattachment-fill procedures defects are arrested. Clinically detectable inflammation must • Hemisection or root amputation be eliminated by scaling and root planing and by the patient's exercise of optimal plaque control. Important: The most critical factor in determining whether a tooth should be extracted or have surgery per formed on it is the amount of attachment loss (which is the apical migration of the epithelial attachment). Numerous therapeutic hard-tissue grafting materials for restoring periodontal osseous defects have been used. Material to be grafted can be obtained from the same individual (autografts), from a different individual of the same species (allografts), or from a different species (xenografts). Bone grafting materials are generally evaluated based on their osteogenic (ability to induce the formation of new bone by cells contained in the graft), osteoinductive (ability of molecules contained in the graft to con vert neighboring cells into osteoblasts), or osteoconductive (ability of the graft material to serve as a scaffold that favors outside cells to penetrate the graft and form new bone) potential. _ ,. _ ,Q A Urvj. Ai*

, ^co^CtVt - Osseous coagulum: mixture of bone dust from cortical hone and blood. I1" - Bone Blend: uses an autoclaved plastic capsule and pestle. Bone is removed from a predetermined site, triturated in the capsule to a workable, plastic-like mass, and packed into bony defects. - Cancellous bone marrow transplants: bone obtained from the maxillary tuberosity or edentulous ridges. - Cancellous bone from extraoral sites: fresh or preserved iliac cancellous marrow bone. • Allograft material: undecalcified freeze-dried bone allograft (FDBA [osteoconductive material]), decal cified FDBA (DFDBA [osteoinductive material]). Note: DFDBA has a higher osteogenic potential (due to the presence of bone morphogenetic proteins [BMPs]) than FDBA and is, therefore, preferred. • Xenografts: Bio-Oss has been used as a graft material covered with a resorbable membrane (Bio-Guide) • Nonbone graft materials: bioactive glass (PerioGlas, BioGran) and coal-derived materials.

• flaps from the palate are considered easier to be displaced thai those from any other region

*** This is false; palatal flaps cannot be displaced (owing to the absence of unattached gingiva). A -periodontal flap is a segment of marginal periodontal tissue that has been surgically sep arated coronally from its underlying support and blood supply and attached apically by a pedicle of supporting vascular connective tissue. Flap procedures are the most com monly used of all periodontal surgical techniques. The most commonly used flaps are full-thickness mucoperiosteal flaps. These flaps.include the surface mucosa (defined as ep ithelium, basement membrane, and connective tissue lamina propria) and the contiguous periosteum of the underlying alveolar bone. A partial-thickness flap includes only the ep ithelium and part of the connective tissue, which is separated from the periosteum by sharp dissection. The periosteum remains in place on the bone. Alveolar bone is not exposed. These flaps are used in thypreparatiqn of recipient sites for free gingival grafts or *hen a dehiscence or fenestration is present on a prominent root. The surgically created edge of the flap must be uniformly thin, usually about 2 mm thick. One determinant of how the flap will be raised, that is either as full-thickness or as a partial-thickness flap, is the thickness (amount) of the attached gingiva prior to sur gery. Generally, a full thickness flap will be used where the attached gingiva is thin (2 mm or less in width), and a partial-thickness flap may be used when the attached gingiva is thick (2 mm or more). Jq,.

^ ~*h« 6k *Q There are various distal flap approaches used for retromolar reduction. The simplest is the:

gingivectomy

apically positioned flap

• distal wedge

• laterally positioned flap

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Contraindications to gingivectomy include all of the following EXCEPT one. Which one is the EXCEPTION!

• the need for bone surgery or examination of the bone shape and morphology

• situations in which the bottom of the pocket is apical to the mucogingival junction

• esthetic considerations, particularly in the anterior maxilla

elimination of gingival enlargements

Distal wedge procedures (sometimes called proximal wedge procedures) are frequently performed after wisdom teeth are extracted because the bone fill is usually poor, leaving a periodontal defect. This region is occupied by glandular and adipose tissue covered by unattached nonkeratinized mucosa. Only if sufficient space exists dis tal to the last molar, a band of attached gingiva may be present. In such a case, a distal wedge operation can be performed.

These procedures are also performed in the following areas of the mouth: • The maxillary tuberosity region • The mandibular retromolar triangle area • Distal to the last tooth in an arch, or mesial to a tooth which approximates an edent ulous area

Many designs have been presented for this flap procedure. However, the basic princi ple is one of making at least two incisions distal or mesial to the tooth and carrying these incisions parallel to the outer gingival wall, thus forming a wedge; the base of which is the periosteum overlying the bone and the apex of which is the coronal gingival surface. Detachment of the wedge from the periosteal base and elimination of the tissues involved in the distal pocket region also reduce tissue bulk and allow for access to the underl ying bone.

• elimination of gingival enlargements Gingivectomy means excision of the gingiva. By removing the pocket wall, gingivectomy pro vides visibility and accessibility for complete calculus removal and thorough smoothing of the roots, creating a favorable environment for gingival healing and restoration of a physiologic gin gival contour. A beveled incision is made apical to the pocket depth, the tissue is removed, the area is debrided, and a surgical pack is placed. Note: The gingivectomy technique was widely per formed in the past. Improved understanding of healing mechanisms and the development of more sophisticated flap methods have relegated the gingivectomy to a lesser role in the current repertoire of available techniques. The gingivectomy technique may be performed for the following indications: • Elimination,.o.£suprab.ony..pockets, regardless of their depth, if the pocket wall is fibrous and firm • Elimination of gingival enlargements • Elimination of suprabony periodontal abscesses Important: An adequate amount of attached gingiva must be present before a gingivectomy is done; otherwise the result will be an area with minimal or no attached gingiva. The following factors should be considered when electing to perform a gingivectomy rather than a periodontal flap: • Pocket depth (if base of pocket is located at the mucogingival junction or apical to the alve olar crest, do not perform gingivectomy) • Need for access to bone (if osseous recontouring is needed, do not do gingivectomy) • Amount of existing attached gingiva (if inadequate, do not do gingivectomy) A gingivoplasty is directed toward reshaping the gingiva and papilla of a tooth for correction of deformities and to provide the gingiva with normal and functional form. The overall objective is not to eliminate periodontal pockets but, rather, to provide a more,physiological tissue contour. While it is true that portions of the gingiva are excised during the gingivoplasty procedure, it is the reshaping, not the excision, of gingiva that defines gingivoplasty. Note: This procedure is com monly used to correct the tissue contours that result from ANUG. The primary objective and advantage of surgical flap procedures in the treat ment of periodontal disease is:

• reduce or eliminate periodontal pockets

• to provide access to root surfaces for debridement

• regrowth of alveolar bone

> maintenance of biological width

> establishment of adequate soft tissue contours

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The modified Widman flap:

• in addition to improving accessibility for instrumentation, removes the pocket wall, thereby reducing or eliminating the pocket

• facilitates instrumentation but does not attempt to reduce pocket depth

• improves accessibility and eliminates the pocket, but does the latter by apically posit ioning the soft tissue wall of the pocket

• none of the above

copyright © 2013-2014 - Dental Decks PERIODONTICS • to provide access to root surfaces for debridement- leo choices are goals but not a primary objective The techniques vary with the goal that is sought. However, the common goal of all flap procedures is to provide access for instrumentation. It gives the clinician the opportunity to vi sualize the roots so that calculus may be removed more completely. Without direct visualization provided by a flap, it is rare that a clinician can effectively root plane beyond 5 mm of probing depth or into furcations of lesser depth. It also makes removal of gran ulomatous tissue from the region of the periodontal defect difficult. It is important to remove this, due to the fact it contains epithelium and the potential presence of bacterial infiltration. Important: If a patient fails to demonstrate adequate oral hygiene during initial therapy (scaling and root planing), surgery is contraindicated because, after surgery, the incidence of disease re currence will be greater if oral hygiene remains poor. The best course of action is to continue to stress oral hygiene and maintain areas with scaling and root planing. The internal bevel incison' is basic to most periodontal flap procedures. It is the incision from which a flap is reflected to expose the underlying bone and root. The internal bevel incision ac complishes three important objectives:

A. Diagram of the internal bevel incision (first incision) to reflect a full-thickness (mucoperiosteal) flap. Note that the incision ends on the bone to allow for the reflection of the entire flap. B. Diagram of the internal bevel incision to reflect a partial-thickness flap. Note that the incision ends on the root surface to preserve the periosteum of the bone.

• facilitates instrumentation but does not attempt to reduce pocket depth

The modified Widman flap (MWF) facilitates instrumentation but does not attempt to reduce pocket depth. The reduction or elimination of pocket depth is the main purpose of two flap techniques: the undisplaced flap and the apically displaced flap. The decision of which to perform depends on two important anatomic landmarks: vPocket depth ^Location of the mucogingival junction *** These landmarks establish the presence and width of the attached gingiva, which is the basis for the decision.

The modified Widman flap has been described for exposing the root surfaces for meticulous instrumentation and for removal of the pocket lining. This flap uses the three horizontal inci sions but is not reflected beyond the mucogingival line. Note: It is not intended to eliminate or reduce pocket depth, except for the reduction that occurs in healing by tissue shrinkage.

The undisplaced (unrepositioned) flap, in addition to improving accessibility for instrumen tation, removes the pocket wall, thereby reducing or eliminating the pocket. This is essentially an excisional procedure of the gingiva. Note: Currently, the undisplaced flap may be the most frequently performed type of periodontal surgery. It differs from the modified Widman flap in that the soft tissue pocket wall is removed with the initial incision; thus it may be considered an "internal bevel gingivectomy." The.undisplaced flap and the^ngivectomv are the two tech niques that surgically remove the pocket wall.

The apically displaced flap also improves accessibility and eliminates the pocket, but it does the latter by apically positioning the soft tissue wall of the pocket. Therefore, it preserves or increases the width of the attached gingiva by transforming the previously unattached kera tinized pocket wall into attahced tissue. f/g/s

A soft tissue graft that is rotated or otherwise repositioned to correct an adjacent defect is called a:

• free gingival graft

• pedicle graft

• connective tissue graft

• frenectomy

What is guided tissue regeneration

«a soft tissue graft used to correct mucogingival junction involvement

• placement of nonresorbable barriers or resorbable membranes and barriers over a bony defect

• a free gingival graft used to increase the amount of attached gingiva

• placement of an autograft to treat a bony defect

The pedicle graft was the first periodontal plastic surgery procedure to be used for root coverage. It provides a superior result from an esthetic standpoint, but is less versatile than the connective tissue graft. Important: The base of the graft remains attached to the donor site to maintain the blood supply.

With pedicle grafts, there is less concern about nutrient flow from graft bed to graft. The properly performed pedicle graft never loses its blood supply during the surgical proce dure. The major advantages of pedicle grafting include: • Predictable correction of gingival recession is possible, because the graft has an un interrupted blood supply • Postoperative discomfort is usually minor • Since the color of the graft matches the adjacent gingiva, the procedure provides good esthetics

Indications include: S^TO widen an inadequate zone of attached gingiva •VTo repair an isolated area of gingival recession

Contraindications include: • The prospective donor site lacks sufficient attached gingiva • The donor site has a fenestration or dehiscence of its supporting bone

Note: Pedicle grafts are not well suited for repairing generalized recession defects. They were designed for repair of isolated recession. Many recession defects don't have a suit able adjacent donor site.

> placement of nonresorbable barriers or resorbable membranes and barriers over a bony defect The method for the prevention .of epithelial migration along .the cemental wall of the pocket that has gained wide attention is guided tissue regeneration (GTR). This method is based on the assumption that only the periodontal ligament cells have the potential for regeneration of the attachment apparatus of the tooth. GTR consists of placing barriers of different types to cover the bone and periodontal ligament, thus temporarily separating them from the gingival epithelium. Excluding the epithelium and the gingi val connective tissue from the root surface during the postsurgical healing phase not only prevents ep ithelial migration into the wound, but also favors repopulation of the area by cells from the periodontal ligament and the bone. The initial membranes developed were nonresorbable (polytetrafluoroethylene [PTFE]) and, therefore, required a second, although frequently simple, procedure to remove it. This second procedure was done after the initial stages of healing, usually 3 to 6 weeks after the first intervention. The second procedure was a significant obstacle in the utilization of this GTR technique, and, therefore, resorbable membranes were developed. Resorbable membranes marketed in the United States include Osseoquest (Gore), a combination of polyglycolic acid, polylactic acid, and trimethylene carbonate that res.orbs at 6 to 14 months; BixjGide (Geistlich), a bilayer porcine-derived collagen; ATRISORB (Block Drug), SL polylactic acid gel; and Bio- Mend (Zimmer Dental), a bovine Achilles tendon collagen that resorbs in 4 to 18 weeks. Of these, BioGide is easiest to use and generally preferred. Currently, regenerative procedures are applicable and predictable under a certain set of circumstances: (1) The patient exhibits exemplary plaque control both before and after regenerative therapy, (2) The patient does not smoke, (3) There is occlusal stability of the teeth at the regenerative site, (4) Osseous defects are vertical in nature, with the more walls of bone remaining, increasing the likelihood of re generative success. 1. A frenum becomes a problem if the attachment is too close to the marginal gingiva. Ten- Notes sion on the frenum may pull the gingival margin away from the tooth. 2. A frenectomy is complete removal of the frenum. 3. A frenotomy is incision of the frenum, this procedure usually is sufficient for most peri odontal purposes. f/g/s

The primary reason for the failure of a free gingival autograft is:

• infection

• edema

• disruption of the vascular supply before engraftment

• the formation of scar tissue

A variation of the laterally positioned flap is called:

a coronally positioned flap

a modified Widman flap

a double papilla flap

a free gingival flap

12 copyright©2013-2014-Dental Decks PERIODONTICS • disruption of the vascular supply before engraftment *** The second most common reason is infection. Techniques used taincrease the width of attached gingiva include fhelree gingival autograft,*ffee con nective tissue autograft, and the, apically positioned flap. These techniques are used for widening the at tached gingiva apical to the area of recession. Techniques used for gingival augmentation coronal to the recessionfroot coverage)linclude the free gingival and connective tissue autograft, as well asjjgdicle autografts (laterally and coronally positioned flaps), the^subepithelial connective tissue graft (Langer), and guided tissue regeneration. Free gingival autografts involve taking a section of attached gingiva from another area of the mouth (usually the hard palate or an edentulous region) and suturing it to the recipient site. The success depends on the graft being immobilized at the recipient site. Free gingival grafts are used to create a widened zone of attached gingiva with the possibility of gaining root coverage as well. The difficulty in getting complete root coverage lies in the fact that an avascular graft is placed over a root surface also devoid of a blood supply. Note: The ideal thickness for this graft is 1 to 1.5 mm. The free connective tissue autograft technique is based on the fact that the connective tissue carries the genetic message for the overlying epithelium to become keratinized. Therefore, only connective tissue from a keratinized zone can be used as a graft. The advantage of this technique is that the donor tissue is obtained from the undersurface of the palatal flap, which is sutured back in primary closure; therefore, healing is by first intention. The apically displaced flap: this technique uses the apically positioned flap, either partial-thickness or full-thickness, to increase the zone of keratinized gingiva. Remember: Positioned flaps (i.e., laterally positioned flap, coronally positioned flap, and apically po sitionedflapjais procedures in which the coronal portion of the flap is elevated from an area adjacent to the recipient site, and freed, but the base of the flap is still connected to the underlying donor site tis sue. In these procedures, the vascular supply to the flap is maintained, as opposed to the free gingi val graft. Important: There is no necrotic slough of positioned flaps because these flaps take their vascular sup ply with them. In a free gingival graft, the healing involves revascularization of the graft. The top lay ers of the graft are the last to be revascularized; therefore the epithelium dies off (degeneration), producing the necrotic slougl}.

• a double papilla flap

Laterally (horizontally) displaced flap: this technique was the standard technique for many years and is still indicated in some cases. The laterally positioned flap can be used to cover isolated, denuded roots that have adequate donor tissue laterally and vestibular depth. Sliding partial-thickness grafts from neighboring edentulous areas (pedicle grafts) can be used to restore attached gingiva on teeth adjacent to edentulous spaces with denuded roots and a small, vestibular fornix, often complicated by tension from a frenum. The "double papilla flap" attempts to cover roots denuded by isolated gingival defects with a flap formed by joining the contiguous halves of the adjacent interdental papillae. Results with this technique are often poor because blood supply is impaired by suturing the two flaps over the root surface. Indications include: • Trauma from incorrect toothbrushing (gingival recession) • Covering the exposed root surface with gingiva also helps to reduce or eliminate the problem of hypersensitivity 1. Deep periodontal pockets are often treated by flap surgery. These cases Notes will often result in reduced pocket depth by formation of a long junctional epithelium (soft tissue reattachment), even if there is no change in the posit ion of the gingival margins. 2. The best indicator of success of a periodontal flap procedure is postoper ative maintenance and plaque control by the patient. 3. One month after flap surgery, a fully epithelialized gingival crevice with a well-defined epithelial attachment is present. Functional arrangement of supra crestal fibers is initiated. f/g/s

All corners of a periodontal flap should be:

•sharp

• rounded

• it doesn't matter whether the corners of a periodontal fla|o are sharp or rounded

Which of the following has a relatively high degree of predictability and is a "workhorse" of periodontal therapy?

coronally displaced (positioned) flap

laterally displaced (positioned) flap

•

• apically displaced (positioned) flap

14 copyright © 2013-2014 - Dental Decks PERIODONTICS • rounded A periodontal flap is a section of gingiva and/or mucosa surgically separated from the underlying tis sues to provide visibility of and access to the bone and root surface. The flap allows the gingiva to be displaced to a different location in patients with mucogingival involvement. Periodontal flaps can be classified based on the following: • Bone exposure after flap reflection: - full-thickness (mucoperiosteal) flaps: all soft tissues, including the periosteum, are reflected to expose the underlying alveolar bone. - partial-thickness (mucosal) flaps: only the epithelium and a layer of the underlying connective tissue are reflected. Also called split-thickness flap. • Based on flap placement after surgery: - nondisplaced flaps: when the flap is retained and sutured to its original position. - displaced flaps: which are placed apically, coronally, or laterally to their original position. • Based on management of the papilla: - conventional flap: the interdental papilla is split beneath the contact point of the two approximat ing teeth to allow reflection of buccal and lingual flaps. - papilla preservation flap: incorporates the entire papilla in one of the flaps. The Four Basic Rules For Flap Design: 1. The base of the flap should be wider than the free margin in order to afford sufficient blood cir culation to the free margin of the flap. 2. The lines of the incision must not be placed over any defect in the bone to prevent delayed heal ing. 3. Incisions that traverse a bony eminence (canine) should be avoided. The mucosa covering bony eminences is thin and healing is slow and may result in an ugly scar formation. 4. All corners of the flap should be rounded. Sharp points will delay healing. Important: • Healing should take place without complication if basic surgical principles are followed. • Incisions made in tissues that harbor uncontrolled infection may cause rapid spread of the infec tion. Do not do this. Most periodontal surgical procedures are performed only after anti-infective therapy has been completed.

• apically displaced (positioned) flap

An. apically displaced (positioned) flap (APF) is a full- or partial-thickness, mucoperiosteal flap. It has a relatively high degree of predictability and is a "workhorse" of periodontal ther apy. The objective of this type of flap is to surgically eliminate deep pockets by positioning the flap apically while retaining the keratinized gingiva. Additionally, surgical access is ob tained for osseous surgery, treatment of infrabony (intrabony); pockets, and root planing. In the course of this flap surgery, after gaining access to the underlying osseous tissue and performing the required therapy, the flap is sutured in place at a more apical level, sometimes exposing the alveolar bone margin. When this is done, additional attached gingiva granulates from the periodontal ligament and covers the barely exposed bone. This additional tissue joins the apically positioned attached gingiva to form a broader zone of gingiva. Note: On the palatal surface of maxillary molars, you need to trim the flap margin to the proper length during the procedure. • IndicationsTor APF) include: v^tvloderate or deep pockets (XFurcation-involved teeth *XCrown lengthening An APF is contraindicated if a patient is at risk for root caries. Excessive root surfaces are often exposed after performing an apically positioned flap. APFs are also contraindicated where tooth exposure would be unesthetic. Remember: For all mucogingival procedures, blood supply is the most significant concern. Biomodification of the root surface: the root surface of the pocket can be treated to improve its chances of accepting the new attachement of gingival tissues. Several substances have been proposed for this purpose, including citric-acid, fibranectin, and tetracycline. Other agents used include growth factors (i.e., PDGF, IGF, bFGF, BMP, and TGF) and one enamel matrix protein derivative obtained from developing porcine teeth (trade name is Emdogain). Which of the following mucogingival surgical techniques is indicated in areas of narrow gingival recession adjacent to a wide band of attached gingiva that can be used as a donor site?

• free gingival autograft

double papilla flap

• modified Widman flap

• laterally displaced (positioned) flap

f/g/s

A free mucosal autograft (subepithelial connective tissae graft) differs from a free gingival graft in that the transplant in a free mucosal graft is:

• connective tissue with an epithelial covering

• connective tissue without an epithelial covering

• epithelial tissue with its own blood supply

> epithelial tissue without its own blood supply

15 copyright © 2013-2014 - Dental Decks PERIODONTICS • laterally displaced (positioned) flap Flaps are classified as (1) nondisplaced flaps, when the flap is returned and sutured to its original position, or (2) displaced flaps: which are placed apically, coronally, or laterally to their original position. Both full-thickness and partial-thickness flaps can be displaced, but to do so, the attached gingiva must be to tally separated from the underlying bone, thereby enabling the unattached portion of the gingiva to be mov able. However, palatal flaps cannot be displaced because of the absence of unattached gingiva.^S^" 1. Apically displaced flaps have the important advantage of preserving the outer portion of the Notes Pocket wall and transforming it into attached gingiva. Therefore, these flaps accomplish the dou ble objective of eliminating the pocket and increasing the width of the attached gingiva. 2. Laterally displaced flaps are used to correct or prevent recession by providing root coverage and creating a broader band of gingiva. It may be used in the absence of recession to widen the zone of gingiva. 3. Displaced flaps are all physically attached at their apical base by a pedicle of lining mucosa and an intact blood supply. Peridontal flaps use horizontal and vertical incisons: Horizontal incisions: are directed along the margin of the gingiva in a mesial or a distal direction. • Internal bevel incision: starts from a designated area on the gingiva and is directed to an area at or near the crest of the bone. The starting point on the gingiva is determined by whether the flap is apically dis placed (0.5-1.0 mm from the free gingival margin), not displaced (just coronal to the base of the pocket), or used in the modified Widman flap (no more than 1 to 2 mm apical to the gingival margin). Also called the first incision (because it is the initial incision in the reflection of the periodontal flap) and the reverse bevel incision (because its bevel is in reverse direction from that of the gingivectomy incision). • Crevicular incision (also termed the second incision): is rnade from the base of the pocket to the crest of the bone. The combination of the internal bevel and crevicular incisions creates a collar of tissue around the teeth and contains most of the inflamed and granulomatous areas that constitute the lateral wall of the pocket, as well as the junctional epithelium and the connective tissue fibers. • Interdental incision (third incision): this incision separates the collar of gingiva from the tooth. These three incisions allow the removal of the gingiva around the tooth and visualization of the alveolar bone. Vertical or oblique releasing incisions: can be used on one or both ends of the horizontal incision, de pending on the purpose of the flap. They are used if the flap is to be positioned apically or laterally and must extend beyond the mucogingival line, reaching the alveolar mucosa, to allow for the release of the flap to be displaced. Note: If no vertical incisior/s are made, the flap is called an envelope flap.

• connective tissue without an epithelial covering A free mucosal autograft (subepithelial connective tissue graft) differs from a free gingival graft in that the transplant in a free mucosal graft is connective tissue without an epithelial covering. Epithelial differentiation is induced by the underlying connective tissue, so that free grafts of dense connective tissue taken from keratinized areas result in the formation of keratinized tissue even when transplanted to nonkeratinized zones. This procedure is somewhat more difficult than free gingival grafting. This procedure is often used on canines where there is little keratinized gingiva to create a band of gingiva-like tissue. Remember: During healing, the epithelium of free gingival grafts degenerates (necrotic slough), and re-epithelialization occurs by proliferation of epithelial cells from adjacent tissue and sur viving basal cells of the graft tissue. Note: Free gingival grafts are often used in conjunction with a frenectomy to prevent reforma tion of high frenal attachments. Healing after flap surgery: • Immediately after suturing (up to 24 hours): a connection between the flap and the tooth or bone surface is established by a blood clot. • 1 to 3 days after surgery: the space between the flap and the tooth or bone is thinner, and_ej>- _jiJlsliaLcs]lsjaaiS2tp over the border of the flap, usually contacting the tooth at this time. • 1 week after surgery: an epithelial attachment to the root has been established by means of hemidesmosomes and a basal lamina. The blood clot is replaced by granulation tissue derived from the gingival connective tissue, the bone marrow, and the periodontal ligament. • 2 weeks after surgery: collagen fibers begin to appear parallel to the tooth surface. Union of the flap to the tooth is still weak because of the presence of immature collagen fibers. • 1 month after surgery: a fully epithelialized gingival crevice with a well-defined epithelial at tachment is present. Functional arrangement of supracrestal fibers is initiated. Note: Full-thickness flaps,,which denude the bone, result in a superficial bone necrosis at 1 to 3 days; osteoclastic resorption follows and reaches a peak at 4 to 6 days, declining thereafter. This results in a loss of bone of about 1 mm; bone loss is greater if the bone is thin. f/g/s

Which of the following terms refer storeshapi ng the bone without removing tooth-supporting bone?

• ostectomy

• osteoplasty

• positive architecture

• negative architecture

17 copyright i 3 2013-2014 - Dental Decks PERIODONTICS

The most common osseous defects are

• one-wall intrabony defects

• two-wall intrabony defects (osseous craters)

• three-wall intrabony defects

• through-and-through furcation defects

18 copyright©2013-20!4-Dental Decks PERIODONTICS • osteoplasty Procedures used to correct osseous defects have been classified in two groups: • Osteoplasty: refers to reshaping the bone without removing tooth-supporting bone • Ostectomy (or osteoectomy): includes the removal of tooth-supporting bone *** One or both of these procedures may be necessary to produce the desired results. Morphologically descriptive terms (these terms all relate to a preconceived standard of ideal osseous form): • Positive and negative architecture refer to the relative position of interdental bone to radicular bone. The architecture is said to be "positive" if the radicular bone is apical to the interdental bone. The bone is said to have "negative" architecture if the interdental bone is more apical than the radicular bone. Flat architecture is the reduction of the interdental bone to the same height as the radicular bone. Note: Osseous form is considered to be "ideal" when the bone is consistently more coronal on the in terproximal surfaces than on the facial and lingual surfaces. The ideal form of the marginal bone has similar interdental height, with gradual, curved slopes between interdental peaks. Following ostectomy, peaks of bone typically remain at the facial and lingual/palatal line angles of the teeth (widow s peaks). If these are not removed, periodontal pockets can recur. Ostectomy to a positive architecture requires the removal of the line-angle inconsistencies (widow s peaks), as well as some of the facial, lingual, and palatal and interproximal bone. The result is a loss of some attachment on the fa cial and lingual root surfaces but a topography that more closely resembles "ideal" bone. Terms that relate to the thoroughness of the osseous reshaping techniques include: • Definitive osseous reshaping: implies that further osseous reshaping would not improve the overall result. • Compromise osseous reshaping: indicates a bone pattern that cannot be improved without signifi cant osseous removal that would be detrimental to the overall result. Note: The relationship between the depth and configuration of the bony lesionfi) to root morphology and the adjacent teeth determines the extent that bone and attachment is removed during resection. The tech nique of ostectomy is best applied to patients with early to moderate bone loss (2-3 mm) with moderate- length root trunks that have bony defects with one or two walls. These shallow-to-moderate bony defects can be effectively managed by osteoplasty and ostectomy. In some surgical procedures, it is necessary to leave interradicular bone exposed. This usually results in bone loss of no clinical consequence.

• two-wall intrabony defects (osseous craters) Horizontal bone loss is the most common pattern of bone loss in periodontal disease. The bone is re duced in height, but the bone margin remains approximately perpendicular to the tooth surface. The in terdental septa and facial and lingual plates are affected, but not necessarily to an equal degree around the same tooth. Vertical or angular defects are those that occur in an oblique direction, leaving a hollowed-out trough in the bone alongside the root; the base of the defect is located apical to the surrounding bone. In most instances, angular defects have accompanying intrabony periodontal pockets; intrabony pockets, how ever, always have an underlying angular defect. Angular defects are classified on the basis of the number of osseous walls. Angular defects may have one, two, or three walls. Xhe number of walls in the apical portion of the defect may be greater than that in its occlusal portion, in which casethe term "combined osseousdefect" is used. Important: Surgical exposure is the only sure way to determine the presence and configuration of vertical osseous defects. The relative degree of success of periodontal bone grafting is reported to vary directly with the number of bony walls of the defect (vascularized, osseous surface area) and inversely with the surface area of the root against which the graft is implanted. Thus a narrow, three-walled angular defect usually yields the greatest succsess, a two-walled defect the next best, and a one-walled defect the least. 1. Osseous grafting techniques and materials include: osseous coagulum, autogenous intra- Notes oral bone, autogenous iliac crest bone, freeze-dried bone allograft (FDBA, which is undecalcified), decalcified freeze-dried bone allograft (DFDBA), FDBA or DFDBA combined with autogenous bone. 2. Root resorption is the most common side effect of osseous grafting. 3. An allograft is a graft taken from one human (donor)'and placed in another human (re cipient). 4. A dehiscence is a loss of the buccal or lingual bone overlaying the root portion of a tooth, leaving the area covered by soft tissue only. 5. The three-wall vertical defect was originally called an intrabony defect. The term intra bony was later expanded to designate all vertical defects. 6. The one-wall vertical defect is also called a hemiseptum. ,_ G#" Two-wall intrabony defects (osseous craters) are best corrected by recontouring of the fa cial and lingual walls to restore normal interdental architecture. ging/pdl dis

Smoking has been identified as a significant variable to predict the response to periodontal treatment.

Smoking has a negative effect on periodontal therapy.

• both statements are true

• both statements are false

• the first statement is true, the second is false

• the first statement is false, the second is true

ging/pdl dis

Prevotella intermedia was formerly known as:

• bacteroides melaninogenicus

• wolinella intermedius

• bacteroides gingivalis

• bacteroides intermedius

Most investigations that evaluated the effect of smoking on nonsurgical therapy have demonstrated less reduction in probing depth and smaller gains in attachment levels in smokers compared with nonsmokers. Depending on which clinical parameters are used to assess periodontal disease, smokers are 2.6 to 6 times more likely to develop periodontal disease than nonsmokers. Important point: Smoking is one of the most significant risk factors currently available to predict the development and progression of periodontitis. Smokers: • Demonstrate more orange and red microbial complexes • Flave an increase in Tannerella forsythia levels • Have a depressed immune system; smoking exerts a significant negative effect on the protective elements of the immune system. Studies show that smoking not only dampens the response of host defense cells, such as neutrophils, but also leads to increased release of tissue-destructive enzymes. 1. Most systemic diseases and conditions that may affect periodontal diseases generally alter Notes host barrier and host defense mechanisms. Although many conditions cause gingival inflam mation and ulcers, not all people develop periodontal disease. Certain factors put individu als at higher risk than others. 2. Osteoporosis (loss of bone density) has been associated with periodontal disease in post menopausal women. There is some evidence that some treatments for osteoporosis, such as bisphosphonates, may reduce bone loss, including the bony structures that support the teeth. 3. Autoimmune conditions (e.g., Crohn disease, rheumatoid arthritis, lupus erythematosus, CREST syndrome) have been associated with a higher incidence of periodontal disease. 4. Smokless tobacco use has been associated with oral leukoplakia and carcinoma. However, no generalized effects on periodontal disease progression seem to occur, other than localized attachment loss and recession at the site of tobacco product placement. 5. Patients receiving radiation therapy show periodontal attachment loss and tooth loss to be greater on the radiated side compared with the nonradiated side. Periodontal health should be established prior to beginning radiation therapy.

bacteroides intermedius

The purpose of this card is to hopefully clear up any confusion on the recent reclassifica tions of a number of peridontal pathogens. The bacteria have stayed the same, but the names have changed.

Recent Reclassification of Periodontal Pathogens Previous Classification New Classification Bacteroides gingivalis Porphyromonas gingivalis Bacteroides endodontalis Porphyromonas endodontalis Bacteroides intermedius Prevotella intermedia Bacteroides melaninogenicus Prevotella melaninogenica Bacteroides denticola Prevotella denticola Bacteroides loescheii Prevotella loescheii Bacteroides forsythus Tannerella forsythia Wolinella recta Campylobacter rectus Wolinella curva Campylobacter curvus ging/pdl dis

Mediators produced as a part of the host response that contribute to tissue destruction include all of the following EXCEPT one Which one is the EXCEP- TION!

• free radicals

• proteinases

• prostaglandins

• cytokines

ging/pdl dis

Which of the following is the LEAST mportant diagnostic aid in recognizing the early stage of gingivitis?

• bleeding on probing

• gingival color

• pocket depths

• stippling of the gingival tissue

Matrix metalloproteinases (MMPs) are considered to be primary proteinases involved in periodontal tissue destruction by degradation of extracellular matrix molecules. MMPs are a family of proteolytic enzymes found in neutrophils, macrophages, fibroblasts, epithelial cells, osteoblasts, and osteoclasts that degrade extracellular matrix molecules, such as collagen, gel atin, and elastin. MMP-8 and MMP-1 are both collaggnases: MMP-8 is released by infil trating neutrophils, whereas MMP-1 is expressed by resident cells, including fibroblasts, monocytes/macrophages, and epithelial cells. Note: MMPs are also produced by periodontal pathogens P^gingivalis and A. actinomycetemcomitans.

Cytokines are important signaling molecules released from cells. Interleukin-1 jJEJ), JL-8, and tumor necrosis factor alpha (TNFa), appear to have a central role in periodontal tissue de struction. The properties of these cytokines that relate to tissue destruction involve stimulation of bone resorption and induction of tissue-degrading proteinases. IL-1 is a potent stimulant of osteoclast proliferation (bone resorption), differentiation, and activation. IL-8 is important in attracting inflammatory cells, and TNFa has similar effects as IL-1 but is musch less potent than IL-1. It is also important in activating macrophages. Note: Monocytes/macrophages are very important in regulating the immune response through the release of cytokines.

Macrophages are recruited to the area of inflammation and are activated (by binding to LPS) to produce prostaglandins (e.g., prostaglandin E2, PGE^. Prostaglandins are biochemically synthesized from the fatty acid, arachidonic acid of cells membranes in repsonse to cy- clooxygenases (COX-1 and COX-2). Cox-2 is upregulated by IL-1, TNF, and bacterial LPS, and it appears to be responsible for generating the prostaglandin (PGE2) that is associated with inflammation. Note: The primary cells responsible for PGE2 production in the peri odontium are macrophages and fibroblasts. Induction of MMPs and osteoclastic bone resorp tion is induced by PGE2. 7^° --> Pcfe a <&-->• ^*«|pT^p>c*

• stippling of the gingival tissue Inflammation, bleeding on probing, and pocket depths are the most important diagnostic aids or signs of gin gival or periodontal disease. Gingiva may or may not be stippled whether healthy or inflamed. The presence or absence of stippling is not diagnostic. Clinical criteria used for diagnosing gingivitis: • Color: normal gingival color ranges from coral pink to various stages of pigmentation. *** Erythema refers to an intense red color. Probably the most common color change noted with pe riodontal disease is cyanosis (bluish-purple hue). ' Contour: has a range of normal. This is influenced by missing teeth, position of teeth, etc. Papillae should fill the interproximal spaces. Gingival margins should be scalloped in form. • Tone (or Consistency): the normal consistency of the gingival tissue should be resilient and fibrotic in nature from the free gingival groove apical to the mucogingival junction. Texture, stippling of the attached gingiva (the so-called orange peel appearance) may or may not be present. •;Size: the healthy gingival tissues should be well contoured to the underlying osseous architecture with the free gingival margin being of such thinness to allow for a "knife edge" thickness at the dentogingival margin. •.Plague, calculus: the best way to evaluate the amount and distribution of plaque is by the utilization of disclosing solution. Remember: Without bacterial plaque, there would be no gingivitis. Important: The impact of nutrition on periodontal disease — there are no nutritional deficiencies that by themselves can cause gingivitis or periodontitis. However, nutritional deficiencies can affect the condition of the periodontium. • Vitamin A deficiency: vitamin A may play an important role in protecting against microbial invasion by maintaining epithelial integrity. A deficiency can impact the barrier function of epithelial cells. • Vitamin D deficiency: vitamin D is essential for the absorption of calcium from the GI tract and for the calcium-phosphorus balance. No human studies demonstrate a relationship between vitamin D deficency and periodontal disease. Note: Vitamin D defeciency can contribute to osteoporosis of alveolar bone in young dogs. • Vitamin B-complex deficiency: vitamin B complex includes thiamin, riboflavin, niacin, pyridoxine, bi- otin, folic acid, and cobalamin. Deficiency of these as a group may contribute to gingivitis. • Vitamin C deficiency: severe deficiency of vitamin C results in scurvy. Bleeding, swollen gingiva, and loosened teeth are common features of scurvy. ging/pdl dis

In a clinically healthy periodontium, the microbial flora is largely composed of:

> gram-negative obligate microorganisms

• gram-negative facultative microorganisms

gram-positive obligate microorganisms

gram-positive facultative microorganisms

ging/pdl dis

Endotoxins are the lipopolysaccharide component of the cell wall of:

gram-positive bacteria

• gram-negative bacteria

• both gram-positive and gram-negative bacteria

• neither gram-positive and gram-negative bacteria

The gingival crevice harbors bacteria in both health and disease. In a clinically healthy periodontium, the microbial flora is largely composed of gram-positive facultative cocci and rods, predominantly species of genera such as Actinomyces and Streptococcus. Gram-negative species and spirochetal forms also may be found, but they are considerably less prevalent and occur in much smaller numbers. The development of gingivitis occurs in parallel with a tremendous increase in the numbers of bacteria present in plaque. A distinct shift in the bacterial composition of the plaque also occurs, with increasing proportions of gram-negative anaerobes. Note: The host-response to plaque bacteria i^ an inflammatory response. Despite a remarkable diversity of bacteria found in the periodontal microbiota, only a few species have been associated with periodontitis. These include: • Porphyromonas gingivalis • Fusobacterium nuclealum • Tannerella forsythia • Actinobacillus actinomycetemcomitans • Prevotella intermedia • Peptostreptococcus micros • Campylobacter rectus . Treponema denticola ' Eikenella corrodens T mportant: Decreases in the prevalence and numbers ofP.,.gingiyalis, '^forsythia, and J^foifco/a are associated with successful clinical treatment of disease. Nonspecific Plaque Hypothesis: maintains that periodontal disease results from the "elaboration of noxious products by the entire plaque flora." Inherent in this hypothesis is the concept that control of pe riodontal disease depends on control of the amount of plaque accumulation. This hypothesis is contra dicted by the finding that some patients with little plaque have severe periodontitis. .Specific Plaque Hypothesis:states that only certain plaque is pathogenic, and its pathogenicity depends on the presence of or increase in specific microorganisms. This concept predicts that plaque harboring specific bacterial pathogens results in a periodontal disease because these organisms produce substances that mediate the destruction of host tissues. Note: Acceptance of this hypothesis was spurred by the recognition of A. actinomycetemcomitans as a pathogen in localized aggressive periodontitis.

• gram-negative bacteria

The cell wall of gram-negative bacteria consists of a lipopolysaccharide (LPS) base, also known as endotoxin, that has significant pathogenic potential. Typically, LPS-containing gram-negative cell wall extracts are capable of promoting bone resorption, inhibiting os teogenesis, chemotaxis of neutrophils, and other events associated with active peri odontitis. Important facts: • Free endotoxin is present in dental plaque and inflamed gingiva • Plaque accumulation has a direct effect on the severity of gingivitis • Plaque bacteria produce enzymes (hyaluronidase, collagenase, chondroitin sulfatase, elastase and proteases) that may initiate periodontal disease. 1. Collagenase (which is produced by Bjud££Qidgs species) catalyzes the degrada tion (hydrolysis) of collagen. 2. Hyaluronidase (which is produced by Streptococcus mitans and salivarius) and chondroitin sulfatase (which is produced by Diphtheroids) may lead to the des truction of the amorphous ground substance. • Antibodies or immunoglobulins are produced by plasma cells in response to oral bacteria or their by-products. The most numerous are IgG, which act to neutralize bacterial toxins by enhancing phagocytosis. • The most likely source of bacteria found in diseased periodontal tissue is subging ival plaque. • The likelihood that bacterial endotoxins play a major role in gingival inflammat ion is evidenced by the following: 1. A reduction in inflammation by the removal of plaque. 2. A reduction of the inflammatory state with antibiotic treatment. Important^Tbe predominant periodontal disease is gingivitis. ging/pdl dis

Which of the following clinical signs and symptoms is characteristic of necrotizing ulcerative gingivitis (NUG)!

minimal bleeding

"punched-out" papillae

• painless

• periodontal pocket formation

ging/pdl dis In a healthy sulcus, which of the bacteria below are most abundant?

actinobacillus actinomycetemcomitans and tannerella forsythus

streptococcus and actinomyces species

treponema and capnocytophaga species

prevotella intermedia and porphyromonas gingivalis

26 copyright © 2013-2014 - Dental Decks PERIODONTICS • "punched-out" papillae Two forms of necrotizing ulcerative periodontal diseases are necrotizing ulcerative gingivitis (NUG) and necrotizing ulcerative periodontitis (NUP). These conditions represent acute forms of periodon tal destruction typically associated with some form of host compromise. The essential components of NUG are: • Interdental gingival necrosis: often described as "punched-out" papillae •Pain • Bleeding *** Variable features include a fetid oris (offensive odor), lymphadenopathy, fever, and malaise. Predominant organisms associated with NUG include PJntermedia Fusobacterium species, and spirochetal microorganisms. Note: EM studies of NUG reveal a zone of tissue infiltration of spiro chetal microorganisms in advance of the region of tissue necrosis. NUG is usually associated with pre disposing host factors, including stress, srnoking, invmunosuppression (as seen with HIV infection), andmalnutrition. NUP is distinguished from NUG by the loss of clinical attachment and bone in affected sites, but the clinical presentation and etiologic factors are similar to that of NUG in the absence of systemic disease. In the presence of systemic immunosuppression, exemplified by HIV infection, NUP may result in rapid and extensive necrosis to the tissues and underlying alveolar bone. The treatment of NUG or NUP includes debridement, hydrogen peroxide (or chlorhexidine) rinses, and antibiotic therapy (Pen^V) if there is systemic involvement (manifested by fever, malaise, and lym phadenopathy). Important: Patients with HIV-associated NUG require gentle debridement and an timicrobial rinses. Note: For patients with acute herpetic gingivostomatitis: • If diagnosed within 3 days of onset, acyclovir suspension should be prescribed, 15 mg/kg five times daily for 7 days • All patients, including those presenting more than 3 days after disease onset, may receive pal liative care, including plaque removal, systemic NSAIDs, and topical anesthetics • Patients should be informed that herpetic gingivostomatitis is contagious at certain stages, such as when vesicles are present

vstreptococcus andactinomyces species

*** Gram-positive cocci (Streptococci) and filamentous bacteria (Actinomyces) are most abundant in a healthy sulcus. Normal inhabitants of the oral cavity: Gram-positive: Gram-negative: • Streptococcus • Veillonella • Corynebacterium • Actinomyces • Campylobacter • Peptostreptococcus • Fusobacterium • Lactobacillus • Eikenella

*** Viridans streptococci consist of a variety of alpha-hemolytic streptococci, including S. salivarius, mutans, sanguis, and mitis, all common oral flora.

Important information: 1 .The oral cavity is usually sterile at birth. Microorganisms appear about 1TAT2 haw&^&SLbjrth. 2. After 1 year, the following bacteria are present: • Streptococci - S. salivarius is most abundant - S. mutans and sanguis do not appear until teeth are present • Staphylococci • Neisseria • Actinomyces • Fusobacterium *** By the age of 4-5, the oral flora resembles that of an adult.o^^ ging/pdl dis

Early microbiologic studies of localized aggressive periodontitis (LAP) pro vided clear evidence of a strong association between disease and a unique bacterial microbiota dominated by:

• tannerella forsythia

• prevotella intermedia

• porphyromonas gingivalis

• actinobacillus actinomycetemcomitans (aa)

ging/pdl dis

Diseases that clinically present as desquamative gingivitis include the following? Select all that apply.

lichen planus

• pemphigoid

• pemphigus vulgaris

• leukemia

• chronic ulcerative stomatitis

• lupus erythematosus

Important: The new classification system for periodontitis is more descriptive and not as temporal as was the previous system. The terms adult, juvenile, early onset, and prepubertal have been replaced with various forms of chronic and aggressive disease. The majority of patients with chronic periodontitis are successfully managed with conventional treatment reg imens. However, a small proportion of patients do not respond to treatment and demonstrate continued clini cal periodontal destruction. These individuals are referred to as "refractory periodontitis patients." In chronic periodontitis, the bacteria most often cultivated at high levels include P. gingivalis, T. forsythia, P. interme dia, C. rectus, E. corrodens, F. nucleatum, A. actinomycetemcomitans (Aa), P. micros, and Treponema andEu- bacterium species. Detectable levels of P. gingivalis, P. intermedia, T. forsythia, C. rectus and A. actinomycetemcomitans (Aa) are associated with disease progression and their elimination by therapy is as sociated with improved clinical response. Note: Recent studies have documented an association bewteen chronic periodontitis and viral microorganisms of the herpesvirus group, most notably Epstein-Barr virus-1 and human cytomegalovirus. The presence of these subgingival viruses is associated with putative bacterial pathogens, including P. gingivalis, T. forsythia, P. intermedia, and T denticola. A primary characteristic of aggressive periodontitis that differentiates it from chronic periodontitis is the rapid progression of attachment and bone loss that is evident. Aggressive periodontitis may be localized or gener alized. The classic form of localized aggressive periodontitis was initially referred to as "periodontosis" and then as "localized juvenile periodontitis" (LJP). Localized aggressive periodontitis (LAP) is the new classifi cation designated to replace LJP. LAP is defined by several distinguishing characteristics: onset around the time of puberty, aggressive peri odontal destruction localized almost exclusively to the incisors and first molars, and a familial pattern of oc currence. Aa is the dominant bacteria in LAP, other microorganisms that have been associated with LAP include P. gingivalis, E. corrodens, C. rectus, F. nucleatum, Bacillus capilfus, Eubacterium brachy, and Capnocytophaga species and spirochetes. Important: The one outstanding negative feature is the relative absence of local fac tors (plaque) to explain the severe periodontal destruction that is present. Generalized aggressive periodontitis (GAP) is differentiated from the localized form by the extent of in volvement around most of the permanent teeth, and it is considered to include rapidly progressing periodon titis. Patients with GAP frequently have subgingival gram-negative rods, including P. gingivalis, and exhibit suppressed neutrophil chemotaxis.

•lichen planus • pemphigoid • pemphigus vulgaris • chronic ulcerative stomatitis • lupus erythematosus

The following diseases also present as desquamative gingivitis; linear IgA disease, dermatitis herpetiform, and erythema multiforme. Desquamative gingivitis (DG) is only a clinical term that describes a peculiar clinical picture. This term is not a diagnosis, and once it is rendered, a series of laboratory procedures should be used to arrive at a final diag nosis. It is important to be aware of this rare clinical entity so as to distinguish desquamative gingivitis from plaque induced gingivitis, which is an extremely common condition, easily recognized, and treated daily by the dental practitioner.

DG is characterized by fiery red, glazed, atrophic or eroded-looking gingiva. There is loss of stippling and the gingiva may desquamate easily with minimal trauma. As opposed to plaque-induced gingivitis, DG is more common in middle-aged to elderly females, is painful, predominantly affects the buccal/labial gingiva, fre quently spares the marginal gingiva but can involve the whole thickness of the attached gingiva, and its clin ical appearance is not significantly altered by traditional oral hygiene measures or conventional periodontal therapy alone. Note: The role of plaque is vague in desquamative gingivitis.

Important point: The multiplicity of causes of DG lesions with a focus on dematologic disease makes it im perative that clinicians develop diagnostic skills and good communication with physicians such as internists and dermatologists. Because microscopic evaluation is the foundation for diagnosis of DG lesions, clinicians must take the responsibility to biopsy all desquamative lesions. The majority of cases of DG are now known to be due to mucocutaneous conditions, in particular lichen planus, pemphigoid, and pemphigus. DG can be mistaken for plaque-induced gingivitis, and this can lead to delayed diagnosis and inappropriate treatment of serious dermatological diseases such as pemphigoid or pemphigus.

Remember: Histologically, where nonulcerated areas are found, the stratified squamous epithelium is signif icantly atrophic. Rete pegs are short or absent. Inflammatory cells, mainly plasma cells, may be found on the basal layer. WMlW"'****''*"*'^ ging/pdl dis

A cuplike resorptive area at the crest of the alveolar bone is a radiographic finding of:

• gingivitis

• occlusal trauma

• early periodontitis

• acute necrotizing ulcerative gingivitis

ging/pdl dis

Which of the following statements regarding periodontitis is incorrect?

periodontitis does not always begin with gingivitis

• gingivitis and periodontitis cannot be induced without bacteria

> there are no radiographic features of gingivitis

• the presence of pockets cannot be determined from radiographs

> chronic gingivitis does not always lead to periodontitis

29 copyright © 2013-2014 - Dental Decks PERIODONTICS • early periodontitis Radiographic Changes in Periodontal Disease: • Early periodontitis: areas of localized erosion of the alveolar bone crest (blunting of the crest in anterior regions and a rounding of the junction between the crest and lamina dura in the posterior Tegionsf" • Moderate periodontitis: the destruction of alveolar bone extends beyond early changes in the alveolar crest and may include buccal or lingual plate resorption, generalized horizontal erosion or localized vertical defects, and possible clinical evidence of tooth mobility. • Advanced periodontitis: the bone loss is so extensive that the remaining teeth show excessive mo bility and drifting and are in jeopardy of being lost. There is usually extensive horizontal bone loss or extensive bony defects. 1. In gingivitis, the radiographic appearance of the bone will be normal. Notes 2- The crest of the alveolar bone is affected in periodontal disease. In health, it lies 1-2 mm below the level of the CEJs of adjacent teeth. 3. A reduction of only 0.5 or 1.0 mm in the thickness of the cortical plate is sufficient to per mit radiographic visualization of destruction of the inner cancellous trabeculae. Important: Diabetes mellitus is an extremely important disease from a peridodontal standpoint. It is a complex metabolic disease characterized by chronic hyperglycemia. Individuals with diabetes have a higher prevalence and severity of peridontal diseae than do those without diabetes. Diabetes does not cause periodontal disease, but studies show that it alters the response of the periodontal tissues to bac terial plaque. Poorly controlled diabetics often have: • Enlarged gingiva, sessile or pedunculated gingival polyps, polypoid gingival proliferations, abscess formation, and loosened teeth • Polymorphonuclear leukocyte deficencies resulting in impaired chemotaxis, defective phagocy tosis, or impaired adherence • The chronic hyperglycemia adversely affects the synthesis, maturation, and maintenance of colla gen and extracellular matrix. Numerous proteins and matrix molecules undergo a nonenzymatic gly- cosylation, resulting in accumulated glycation end products (AGEs).This increase in AGEs affects how collagen is normally repaired or replaced and may play a role in the progression of peridontal dis-

• periodontitis does not always begin with gingivitis Periodontitis always begins as a gingivitis, which is usually due to local irritation, primarily plaque, and the inflammation then spreads from the gingiva and soft tissues into the underlying structures. Gingivi tis and periodontitis cannot be induced without bacteria (plaque): Periodontitis is inflammation that affects and destroys the attachment apparatus. The clinical feature that distinguishes periodontitis from gingivitis is the presence of clinically detectable attachment loss. This often is accompanied by periodontal pocket formation and changes in the density and height of subjacent alveolar bone. Important: The progress of periodontitis may be arrested with proper therapy. Remember: There are no radiographic features of gingivitis. In periodontitis, radiographic changes are noted, which may include the following: • loss of lamina dura • horizontal or vertical bone resorption • thickening (widening) of the periodontal ligament space Clinical signs of inflammation, such as changes in color, contour, and consistency and bleeding on prob ing, may not always be positive indicators of ongoing attachment loss. However, the presence of con tinued bleeding on probing at sequential visits has proven to be a reliable indicator of the presence of inflammation and the potential for subsequent attachment loss at the bleeding site. 1. Important: The presence of pockets cannot be determined from the evaluation of ra- Notes diographs. 2. Gingivitis does not always lead to periodontitis. Chronic gingivitis may exist for long pe riods without advancing to periodontitis. 3. Severe periodontal disease may be seen in patients withJJfctediak-Higashi syndrome,,Parjil- lon-Lefevre syndromeLDjavn syndrome (increased levels of P. intermedia have been found)Az@[ leukocyte syndrome, andieijkecyte adhesion deficiency (LAD) 4. Chronic stress appears to have effects on the periodontium. The mostnotable example is the documented relationship between stress and acute necrotizing ulcerative gingivitis (NUG). 5. Hypophosphatasia, congential heart disease, tetralogy of Fallot, and Eisenmenger syndrome may be associated with increased severity of periodontal disease. 6. Ingestion of heavy metals (i.e., bismuth, lead, and mercury) may result in changes in the pe riodontium. ging/pdl dis

Which of the following is most significant in regard to the prognosis of a periodontally involved tooth?

pocket depth

attachment loss

anatomical crown length

bleeding on probing

ging/pdl dis

Gingivitis is most often caused by:

• a hormonal imbalance

• inadequate oral hygiene

• occlusal trauma

• a vitamin deficiency

• aging

32 copyright © 2013-2014 - Dental Decks PERIODONTICS • attachment loss Attachment loss is much more significant than periodontal pocketing (actually it is the most significant fac tor) because with attachment loss, supportive structures are being destroyed. Pocket depth is the distance between the base of the pocket and the gingival margin. The level of attachment on the other hand, is the distance between the base of the pocket and a fixed point on the crown, such as the CEJ. Changes in the level of attachment can be caused only by gain or loss of attachment and, thus, provide a better indication of the degree of periodontal destmction. Important: The two most critical parameters for the prognosis of a periodontally involved tooth are attach ment loss (most critical) anfTjHtSfiility. "^ In periodontics, factors often considered in the generation of a prognosis include, but are not limited to, tooth type, furcation involvement, bone loss, pocket depth, tooth mobility, occlusal force, patient's home care, pres ence of systemic disease, and cigarette smoking. The prognosis is usually classified as excellent (no bone loss, gingival health, good patient cooperation, no secondary systemic or environmental factors), good (adequate bone support, good patient cooperation, no environmental facctors, and well-controlled systemic factors), fair (less than adequate bone support, mobil ity, grade I furcation involvement, good patient cooperation, and limited environmental and/or systemic fac tors), poor (moderate to advanced bone loss, mobility, grade I and II furacation involvement, questionable patient cooperation, and presence of environmental and/or systemic factors), questionable (advanced bone loss, grade IandIIfuraction involvements, mobility, and presence of enyironmenta7"ah"a7orsystemic factors), and hopeless (advanced bone loss, inability to establish maintainable situation, and the presence of uncon trolled environmental and/or systemic factors — extraction(s) is/are indicated). 1. Pocketing can increase or decrease, depending on the amount of inflammation without attach- Notes ment loss. On the other hand, extensive attachment loss and gingival recession may be accompa- I nied by shallow pockets (poor prognosis of tooth). 2. When the gingival margin is located on the anatomic crown, the level of attachment is deter mined by subtracting from the depth of the pocket the distance from the gingival margin to the CEJ. If both are the same, the loss of attachment is zero. 3.When the gingival margin coincides with the CEJ, the loss of attachment equals the pocket depth. 4. When the gingival margin is located apical to the CEJ, the loss of attachment is greater than the pocket depth, and therefore, the distance between the CEJ and the gingival margin should be added to the pocket depth.

• inadequate oral hygiene — this leads to the formation of bacterial plaque and its products, which are the primary etiologic factors in gingivitis

The initial microbiota of acute gingivitis consists of gram-positive rods, gram-positive cocci, and gram- negative cocci. The transition to gingivitis is evident by inflammatory changes and is accompanied first by the appearance of gram-negative rods and filaments, then by spirochetal and motile organisms. The microbiota of chronic gingivitis consists of approximately equal proportions of gram-positive (56%) and gram-negative (44%) species, as well as facultative (59%) and anaerobic (41%) microorganisms. Pre dominant gram-positive species include S. sanguis, S. mitis, S. intermedius, S. oralis, A. viscosus, A. naeslundii, and P. micros. The gram-negative microorganisms are predominantly F. nucleatum, P. in termedia, and V.parvula, as well as Haemophilus, Capnocytophaga, and Campylobacter species. Comparing the microbiota in health, gingivitis, and periodontitis, the following microbial shifts can be seen: . From gram-positive to gram negative • From facultative anaerobes to obligate aerobes • From cocci to rods • From fermenting to proteolytic species • From nonmotile to motile organism All surfaces of the oral cavity (both hard and soft tissues) are coated with a pellicle (initial phase of plaque development). Within nanoseconds after vigorously polishing the teeth, a thin, saliva-derived layer, called the acquired pellicle, covers the tooth surface. This pellicle consists of numerous compo nents, including glycoproteins (mucins), proline-richproteins, phpsphoproteins (e.g., statherin), histidine- rich proteins, enzymes (e.g., alpha-qmylase), and other molecules that can function as adhesion sites for bacteria (receptors). Halitosis (bad breath/oral malodor): At least 85% of breath malodors have an oral source. Gingivitis, periodontitis, and tongue coating are the predominant causes of bad breath. The gram-negative anaero bic bacteria associated with gingivitis and periodontitis cause bad breath by their proteolysis, which pro duces foul-smelling volatile sulfide compounds (VSCs). 1. The overall pattern observed in dental plaque development is a very characteristic shift Notes from the early predominance of gram-positive facultative microorganisms to the later predominance of gram-negative anaerobic microorganisms. 2. The major factor in determining the different bacteria is oxygen. The redox potential of the gingival sulcus greatly influences the bacterial composition. ging/pdl dis

Which of the following needs to be evident in to make a diagnosis of peri odontitis?

> bleeding

• pocket depths of 5 mm or more

radiographic evidence of bone loss

a change in tissue color and tone

ging/pdl dis

The degree of gingival enlargement can be scored as follows: Grade 0, Grade 1, Grade II, and Grade III. Enlargement confined to the interdental papilla would be scored as:

• grade 0

• grade 1

• grade II

• grade III

34 copyright © 2013-2014 - Dental Decks PERIODONTICS i • radiographic evidence of bone loss Note: Bitewing x-rays tend to be most accurate in assessing alveolar bone resorption. If extensive bone loss has occurred, vertical bitewings should be taken. They will reveal more of the periodontium. Bone loss may be horizontal or vertical. Also remember that more than 30% of the bone mass at the alveolar crest must be lost for a change in bone height to be recognized on radiographs. Remember: The clinical feature IHa^ferftfptslferp^Hc^rjffi the presence of clinically detectable attachment loss. Other clinical criteria that should be evaluated during a periodontal exam (besides color, tone, contour, and size of gingiva): • Level of the free gingival margin in relation to the CEJ: the normal level of epithelial attachment should be on enamel or at.the CEJ. This would place the free gingival margin 2 to 3 mm coronal to this sulcular base, on enamel.. • Periodontal pocket depth: all measurements in excess of 3 mm are recorded for sulcular depth, as well as any reading that locates the free gingival crest 2 mm or more apical to the CEJ. *** The loss of attachment is determined by measuring the disttance between the CEJ and the base of the attachment. • Bleeding: physiologically, bleeding from the gingival sulcus should not be caused by gentle provocat ion. Bleeding in the absence of local irritants may indicate a systemic disease. • Exudate: the presence of exudate, specifically suppuration (which is due to the presence of large num bers of neutrophils in the pocket), is evaluated by digital pressure on the buccal and lingual of each tooth. • Mucogingival complications: this term indicates the involvement of not only the gingival component in the disease state, but also the presence of imminent involvement of the alveolar mucosa. The following should also be noted: • Erosion: usually found on the cervical area of the facial surface of a tooth. • Abrasion: loss of tooth structure by mechanical wear — horizontal toothbrushing with a hard tooth brush and abrasive dentifrice is the most common cause. • Attrition: occlusal wear due to functional contacts with opposing teeth. Results in wear facets on the occlusal surfaces of teeth. • Abfraction: occlusal loading resulting in tooth flexure, mechanical microfractures, and tooth structure loss in the cervical area. • Hypersensitivity of roots: due to exposure of dentinal tubules to thermal changes following recession and removal of cementum by toothbrushing, root decay, or scaling and root planing.

• grade I The degree of gingival enlargement can be scored as follows: • Grade 0: no signs of gingival enlargement • Grade I: enlargement confined to interdental papillae • Grade II: enlargement involves papilla and marginal gingiva • Grade EH: enlargement covers three-quarters or more of the crown Using the criteria of location and distribution, gingival enlargement is designated as follows: • Localized: limited to the gingiva adjacent to a single tooth or group of teeth • Generalized: involving the gingiva throughout the mouth • Marginal: confined to the marginal gingiva • Papillary: confined to the interdental papilla • Diffuse: involving the marginal and attached gingivae and papillae • Discrete: an isolated sessile or pedunculated, tumorlike enlargement Gingival enlargement may result from chronic or acute inflammatory changes; clrfflffle^lvanges are much more common. Chronic inflammatory gingival enlargement originates as a slight ballooning of the interdental papilla and marginal gingiva. In the early stages, it produces a life preserver-shaped bulge around the involved teeth. This bulge can increase in size until it cov ers part of the crowns. The enlargement may be localized or generalized and progresses slowly and painlessly. Note: Chronic inflammatory gingival enlargement is caused by prolonged exposure to den tal plaque. Factors that favor plaque accumulation and retention include poor oral hygiene, as well as irritation by anatomic abnormalities and improper restorative and orthodontic ap pliances. Important: A pseudopocket is a pocket formed by gingival enlargement_withont apical migration of the junctional epithelium. It does not involve the loss of bone. Pseudopockets are also referred to as gingival, false, or relative pockets. All pseudopockets are suprabony (the

D r ° 4MMP* r MI i ii £ • i 1.1 . MI ii • ' base of the pocket is coronal to the crest of the alveolar bone). ging/pdl dis

The most important plaque retentive factor is:

• subgingival and/or overhanging margins of restorations

• carious lesions that extend subgingivally

• calculus

• furcations exposed by loss of attachment and bone

* crowded and malaligned teeth

> root grooves and concavities

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ging/pdl dis

During pregnancy there is an increase in levels of both progesterone and estrogen.

The so-called pregnancy tumor is not a neoplasm.

• both statements are true

• both statements are false

• the first statement is true, the second is false

• the first statement is false, the second is true

Distinguishing between the effects of calculus and plaque on the gingiva is difficult because calculus is always covered with a nonmineralized layer of plaque. The nonmineralized plaque on the calculus surface is the prin cipal irritant, but the underlying calcified portion may be a significant contributing factor. It does not irritate the gingiva directly but provides a fixed nidus for the continued accumulation of plaque and retains it close to the gingiva. Plaque initiates gingival inflammation, which starts pocket formation, and the pocket, in turn, provides a shel tered area for plaque and bacterial accumulation. The increased flow of gingival fluid associated with gingi val inflammation provides the minerals that convert the continually accumulating plaque into subgingival calculus. Calculus (which is mineralized bactrialplaque) plays an important role in maintaining and accentuating pe riodontal disease by keeping plaque in close contact with the gingival tissue and creating areas where plaque removal is impossible. Other contributing or complicating factors in periodontal disease include: • Food impaction or retention: overlapping, malposed, tilted, or drifted teeth are frequently associated with food impaction or retention. If not removed, this will lead to inflammatory periodontal disease. • Open and loose contacts: leads to food impaction and possible retention. • Overhanging margins of restorations and improperly designed prostheses: can contribute to the ini tiation of periodontal disease. There is a direct correlation between surface roughness or mariginal irregu larities of a restoration and the retention of plaque. • Soft or sticky consistency of diet: food debris tends to collect between the teeth and along the gingiva and can be a prominent cause of inflammation. • Violation of the "biologic width": if margins of a restoration infringe on the biologic width (junct ional epithelium and connective tissue attachement), gingival inflammation, pocket formation, and alveo lar bone loss may occur.. Note: The average biologic width is approximately 2 mm (approximately 0.97 mm for the junctional epithelium and 1.07 mm for the connective tissue attachment). • Occlusal trauma • Orthodontic therapy: has been shown to increase plaque retention and to result in increases in the num bers of P. melaninogenica, P. intermedia, and A. odontolyticus.

• both statements are true Pregnancy gingival enlargement may be marginal and generalized or may occur as single or multiple tumorlike masses. During pregnancy, there is an increase in levels of both progesterone and estrogen. These hormonal changes induce changes in vascular permeability, leading to gingival edema and an increased inflammatory response to den tal plaque. Note: The subgingival microbiota may also undergo changes, including an increase in Erevotellainter media. These bacteria crave steroid hormones for their-.own-metabolism. The enlargement is usually generalized and tends to be more prominent interproximally than on the facial and lingual surfaces. The enlarged gingiva is bright red or magenta, soft, and friable and has a smooth, shiny surface. Bleeding occurs spontaneously or on slight provocation. Note: Usually appears in second or third month. The so-called pregnancy tumor is not a neoplasm; it is an inflammatory response to bacterial plaque and is modi fied by the patient's condition. It usually appears after the third month of pregnancy but may occur earlier. The lesion appears as a discrete, mushroomlike, flattened spherical mass that protrudes from the gingival margin or, more often, from the interproximal space and is attached by a sessile or pedunculated base. Important: Most gingival disease during pregnancy can be prevented by the removal of plaque and calculus, as well as the institution of fastidious oral hygiene at the outset. Gingival diseases modified by systemic factors: endocrine changes during pregnancy, puberty, and diabetes. Blood dyscrasias (i.e.Jeukemia) may impact the immune response as well. Gingival diseases modified by medications: antfconvulsants,^intihypertensive,calcium channel blockers, and^»- munosuppressant drags are known to cause gingival enlargement. Non-Plaque-Induced Gingival Lesions: • Gingival diseases of specific bacterial origin: Neisseria gonorrhoeae, Treponema pallidum, Streptococcus species. • Gingival diseases of viral origin: Herpesvirus infections (Primary herpetic gingivostomatitis, Recurrent oral herpes, Varicella zoster) • Gingival diseases of fungal origin: Candidiasis (caused by Candida albicans) • Gingival diseases of genetic origin: Hereditary gingival fibromatosis I • Gingival manifestations of systemic conditions: may appear as desquamative lesions, ulcerations of the gingiva, or both • Traumatic lesions: may be factitious (unintentionally produced) as in the case of toothbrush trauma, iatrogenic (induced by the dentist), as in the case of restorative care that may lead to traumatic injury of the gingiva, or ac cidental, as in the case of damage to the gingiva through minor burns from hot foods or drinks. ging/pdl dis

Conditions in which the influences of periodontal infection are documented include the following. Select all that apply.

• coronary heart disease

• atherosclerosis

• stroke

cirrhosis of the liver

diabetes mellitus

low-birth-weight delivery

ging/pdl dis

PMNs are the predominant immune cells in which stage of gingivitis?

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Although the potential impact of many systemic disorders on the periodontium is well documented, recent evidence Organ Systems and Conditions Possibly Influenced by Periodontal Infection suggests that periodontal infection may significantly en Cardiovascular / Cerebrovascular System hance the risk for certain diseases or alter the natural course Atherosclerosis of systemic conditions (see chart on right). Coronary heart disease (CHD) Angina Myocardial infarction (MI) Cerebrovascular accident (stroke)

Endocrine System Diabetes mellitus

Reproductive System Preterm low-birth-weight (LBW) infants

Respiratory System Chronic obstructive pulmonary disease (COPD) Acute bacterial pneumonia

1. The relationship between diabetes mellitus and periodontal disease has been extensively exam- Notes med. It is clear that diabetes increases the risk for and severity of periodontal diseases. The in creased prevalence and severity of periodontitis typically seen in patients with diabetes, especially those with poor metabolic control, led to the designation of periodontal disease as the "sixth com plication of diabetes." The others are retinopathy, nephropathy, meuropathy, magtovascular dis ease, and altered wound healing. 2. When considering factors that increase an individual's risk for developing periodontitis, it has been recognized that genetic, environmental (e.g., tobacco use), and acquired risks factors (e.g., systemic disease) can increase a patient's susceptibility to developing this disease. Risk factors can affect onset, rate of progression, and severity of periodontal disease, as well as response to ther apy.

Neutrophils, or polymorphonuclear leukocytes (PMNs), predominate in the early stages of gingival inflam mation, and these cells phagocytose and kill plaque bacteria. Bacterial killing by PMNs involves both intra cellular mechanisms (after phagocytosis of bacteria within membrane-bound structures inside the cell) and extracellular mechanisms (by release ofPMN enzymes and oxygen radicals outside the cell). These enzymes include the MMPs (matrix metalloproteinases), such as collagenases (MMPS and MMP-1), which break down collagen fibers in the gingival and peridontal tissues. Note: Oxygen radicals (superoxide and hydrogen per oxide) produced by PMNs and macrophages are toxic as well to cells of the periodontium having a direct ef fect on cell functions and DNA.

Stages of Gingivitis Stage Time Blood Vessels Junctional and Predominant Collagen Clinical (Days) Sulcular Epithelia Immune Cells Findings I. Initial 2-4 Vascular dilation Infiltration by PMNs PMNs Perivascular Gingival lesion Vasculitis loss fluid flow II. Early 4-7 Vascular Same as stage I Lymphocytes Increased Erythema lesion Proliferation Rete pegs loss around Bleeding on Atrophic areas infiltrate probing III. Established 14-21 Same as stage II, Same as stage II but Plasma cells Continued Changes in lesion plus blood stasis more advanced loss color, size, texture, etc.

Stage IV Gingivitis — The advanced lesion: extension of the lesion into alveolar bone characterizes a fourth stage known as the advanced lesion or phase of periodontal breakdown. Microscopically, there is fibrosis of the gingiva and widespread manifestations of inflammatory and immunopathologic tissue damage. In general at this advanced stage, plasma cells continue to dominate the connective tissues, and neutrophils continue to dominate the junctional epithelium and gingival crevice. Note: Abnormalities in neutrophil function found in patients with neutropenia, agranulocytosis, Chediak-Hi- gashi syndrome, Papillon-Lefevre syndrome, leukocyte adhesion deficiency type 1 (LAD-1), and leukocyte adhesion deficiency type 2 (LAD-2) make the patient more susceptible to aggressive periodontitis. Remember: The four stages of the periodontal lesion are: initial, early, established, and advanced. ging/pdl dis

The frequency of maintenance visits for a patient who has had previous periodontal treatment should depend on which two factors?

• on whether or not the patient feels that frequent visits will help maintain his/her periodontium

• on the appearance and clinical condition of the gingival tissues

• on the amount of attachment loss prior to the periodontal treatment

• on the patient's ability to perform in-home-care

If one of the steps in the fabrication of your implant restoration is attaching an analogue to the impression post and then seating them both into the set impression material, you have made a/an:

• open-tray impression

• closed-tray impression

• either of the above

• neither of the above

40 copyright O 2013-2014 - Dental Decks PERIODONTICS • on the appearance and clinical condition of the gingival tissues — this will determine if the patient is maintaining adequate plaque control • on the patient's ability to perform in-home-care — this will determine the effective ness of the patient's oral hygiene

The main goal of the dentist, dental hygienist, and patient is the maintenance of good oral health. This will prevent the recurrence of disease, which is the main objective of the maintenance phase of peri odontal therapy. The primary cause of recurrence of disease is the dental team's failure to motivate the patient to practice effective plaque control.

The first year after treatment is a critical period, since the patient has already demonstrated suscepti bility to periodontal disease, the cause of which tends to be persistent and recurrent. The appearance and condition of the gingival tissues will determine if the patient is maintaining adequate plaque control.

—_ 1. Bleeding during circumferential probing indicates that the crevicular epithelium is ulcer- Notes ated due to active periodontal disease. 2. After periodontal treatment, the first recall visit should be scheduled at Joapnths. With ex cellent plaque control and maintenance of periodontal health, the interval may be lengthened to 4 to 6 months. IMHLII 1111 "I'lWi.JUIJIn.l.iiillM.nt Remember: 1. Puberty is often accompanied by an exaggerated response of the gingiva to plaque. Gonadotropic hormones during puberty may lead to increased levels of P. intermedia and. Capnocytophaga species in the dental plaque. 2. As a general rule, the menstrual cycle is not accompanied by notable gingival changes, however, increased gingival bleeding is often seen during this time. 3. Hormonal contraceptives aggravate the gingival response to local factors similar to that seen in pregnancy. 4. Oral disturbances are not a common feature of menopause. Some females may develop gingivos tomatitis. 5. Patients with blood dyscrasias (i.e., leukemia, anemia, neutropenia, agranulocytosis, thrombocy topenia purpura, etc.) often demonstrate disturbances to the gingiva and periodontium.

• closed-tray impression

A closed tray impression refers to the impression being made in a tray with no access hole cut over the implant, and with an impression coping in place in the mouth attached directly to the implant or abutment. When the impression tray and impression material are re moved from the mouth after setting, the impression coping remains in the mouth, still at tached to the implant or abutment. The coping (also called the impression post) is removed from the mouth, joined to an implant analogue (also called an implant replica), and the analogue and impression coping are inserted back into the set impression mate rial before the cast is poured. This is also called an indirect transfer impression technique.

When making a pick-up impression, the impression coping is already attached to the abut ment by a retaining screw when the impression tray and impression material are placed into the mouth. After the impression material has set, the retaining screw is released (un screwed) through a hole in the tray, and the impression coping is freed from the implant. When the tray is removed from the mouth, the impression coping remains in the impres sion material. This technique is also called an open top tray pick-up impression.

A pick-up impression may be used with divergent implants.

The master impression should accurately relate the implants and/or abutments to each other, the opposing occlusion, and adjacent teeth. For the impression to be accurate, all of the components must be properly seated at the time of the impression. Verification of the proper seating ("down ") of the abutments is difficult if the junction or the impression coping-to-implant interface is subgingival. Radiographic verification of seating is required before the impression is made. implants

An "implant level impression" means that:

* the impression coping (or impression post) was attached to the implant

• the impression coping was attached to the abutment

• the impression captured or recorded the actual abutment attached to the implant

• none of the above

implants

Which of the following is NOT an advantage of retaining an implant-sup ported crown to an abutment with a screw (rather than with cement)!

• the crown is retrievable

• the residual cement excess in the sulcus is avoided

• the occlusal surface of the crown is left intact

• a shorter abutment may be used

The impression coping (or impression post) was attached to the implant at the time of the impression, thus recording the implant position at the "implant level." If the impression coping was instead attached to the abutment (which was attached to the implant), the im pression is termed an "abutment level impression."

If the impression is made of the already seated abutment without the use of an impression coping, just as a standard crown and bridge impression of a prepared abutment, it is a di rect impression of the abutment.

e occlusal surface of the crown is left intact

Access to the retaining screw that holds the restoration onto the abutment requires an ac cess hole through the crown. This access hole must be restored after the final torque is ap plied to the retaining screw. This restoration is subject to failure and may need replacement periodically. In addition, this restoration is sometimes in the area of the crown that is in occlusion. The hole and restoration in the occlusal surface can be undesirable because of the esthetic compromise that results.

An abutment retaining screw should be tightened to a specified torque to minimize the possibility of future loosening of the screw or the components. A torque wrench (or torque controller) measures and controls the amount offeree or torque applied to the screw. This torque force applied to a screw is called preload. Implant manufacturers provide recom mended torque values that are optimal for their particular components, materials, and de sign.

Remember: In implant dentistry, an "open tray" impression is used because the abutment retention screw must be unscrewed after set.

The abutment retaining screw must be unscrewed after the impression material sets, but before the tray is removed from the mouth, thus releasing the abutment from the implant. Before the impression procedure, a hole is cut in the tray, usually directly occlusal to the abutment retention screw, to allow access of a hex driver or screwdriver to the head of the screw. This feature makes the tray an "open tray" rather than a "closed tray" (no hole). After the abutment retention screw is released, the tray is removed from the mouth with the abutment still encased in the set impression material. This is also called a "pick-up" impression. implants In implantology, "countersinking" refers to the process of:

• flaring or enlarging the coronal end of the osteotomy

> reversing the engine to remove the implant

• placing the implant in a counterclockwise rotation

i torquing the abutment to place

implants

The purpose of the second-stage surgery in the creation of an implant restora tion is to:

check on healing progress

• remove the implant for cleaning

• uncover the implant and place an abutment

• determine which components will fit

• all of the above

As one of the final steps in creation of the osteotomy to receive the implant body, a spe cial bur is activated and inserted into the occlusal end of the osteotomy to increase the di ameter of the opening slightly, or to otherwise shape it. This step is referred to as "countersinking." Countersinking the implant osteotomy is called for by some manufacturers to compensate for very dense cortical bone or to prepare the bone for a particu lar implant shape, e.g., a flared implant shape at the coronal end.

Another one of the final steps in the creation of the osteotomy is to place a threaded bur into the osteotomy to create a spiral groove on the wall of the osteotomy. This groove is placed to receive and guide the threads on the side of the implant during surgical place ment and thus minimize the torque required and to minimize heat. This process of creat ing the groove on the inside of the osteotomy wall is referred to as "tapping" the osteotomy.

All of the burs used to create the osteotomy are used at relatively slow speeds (r.p.m.) to prevent injury to the bone, especially overheating of the bone. Also, water or saline irri gation is used to cool the burs and the bone during drilling.

• uncover the implant and place an abutment

In two-stage implant systems (also referred to as two-piece or submerged systems), the first-stage surgery is placement of the implant in the bone. Then a period of time is allowed for healing, meaning osseointegration and healing of the gingiva over the top of the im plant. After this healing, the second-stage surgery is performed to uncover the implant, make sure there is access to it, and place an abutment (e.g.. a healing abutment). Another period of healing is allowed for healing and maturation of the gingiva.

In one-stage systems (also called one-piece or nonsubmerged systems), the implant is left partially or completely exposed at the time of surgical placement, and the second-stage surgery is avoided. implants The"macro design"of implants describes:

• screw or cylinder shape

• surface texture

• alloy composition

• surface coatings

• none of the above

implants

The soft tissue interface between the oral tissue and titanium can be? Select all that apply.

• established by keratinized mucosa

• established by nonkeratinized mucosa

• dependent on hemidesmosomes

• comparable with the interface on teeth

Dental implants are manufactured in several categories of design and shape, such as blades and root form implants. Root form implants are produced as a straight cylinder or as a basic screw design having threads. This basic overall design is the macrostructure of the implant. A cylinder-shaped implant is pressed into a tight fitting osteotomy (press fit). A screw-shaped implant is screwed into the bone, and this provides added stability. Screw- shaped implants can be tapered. Implant macrostructure is also referred to as "implant • :,,••' —Km ii.iJ,.—|i' geometry." The microstructure of the implant is descriptive of the surface quality or surface alter ation. Implant surfaces can be described as "machined," which is a relatively "smooth" surface as produced by the original milling process. It is not as smooth as a "polished" sur face, such as the polished collar prepared for gingival soft tissue attachment. Implant sur face alterations are secondarily incorporated to produce surface roughness, which has been shown to be more advantageous than smooth surfaces for promoting osseointegra tion. Sandblasting, acid etching, and titanium plasma spray processes are examples of the roughening techniques. Chemical additives can be applied to enhance bone apposition (e.g., hydroxyapatite surface coatings). N\>>

• established by keratinized mucosa • established by nonkeratinized mucosa • dependent on hemidesmosomes • comparable with the interface on teeth

The implant or the abutment must pass through the gingiva to be utilized in the mouth. The epithelial attachment to titanium can be formed by keratinized gingiva or by non keratinized mucosa and is comparable to the analogous attachment of long junctional epithelium to the tooth. The epithelial attachment is composed of hemidesmosomes and a basal lamina. In addition, a sulcular epithelium forms. Between the junctional epithelium and the bone, a zone of connective tissue is present. Implants have a "biologic width" of 3 to 4 mm. Connective tissue fibers are present as circular fibers oriented parallel to the implanfoTabutment surface, but no connective tissue fibers insert into titanium. E^- itheliumfonns apically.toapproximately 1 to 1.5 mm from the crestal bone around the im plant. When considering probing depths around implants and the associated at tachment level, what landmark is used to determine the"clinical"attachment level?

• CEJ

• apical end of the implant

• ball tip of the probe

• implant shoulder or other permanent physical structure

• radiograph

implants

The advantage of using a screw--shaped irr iplant instead of a straight cylinder implant without threads is:

• easier osteotomy preparation

• increased initial stability

• less force required to insert the irr iplant

• no antirotational components are necessary

When determining the attachment level on teeth, the CEJ is used as the landmark to de termine attachment level. Because an implant and its restoration have no CEJ, another permanent and accessible structure must be selected to be the landmark. This is often the •shoulder of the implant or the restoration margin. The correct terminology for this meas urement becomes "relative attachment level," relative to the selected landmark, instead of "clinical attachment level" on a tooth. Probing depths around implants are determined with standard-shaped periodontal probes, with plastic probes generally recommended in stead of metal probes.

• increased initial stability

A screw-shaped implant engages the walls of the osteotomy and is, therefore, more likely to be stable. The osteotomy preparation might be more difficult to accomplish if tapping the site is required. ("Tapping" in this context means producing thread grooves inside the osteotomy that are meant to receive the threads of the implant.) The clinician's control over the vertical positioning of the implant is increased when using a threaded "screw" im plant as opposed to a "press fit" implant that relies more on precise preparation and siz ing of the osteotomy for frictional holding of the implant.

Note: Antirotational elements are incorporated to prevent rotation of the attached abut ment or the restoration, not the implant itself. implants

Which of the following occlusal conditions would exert the lowest amount of biting force under normal conditions?

• complete dentures resting on soft tissue

> complete dentures supported by implants

• fully dentate occlusion

• maxillary complete denture opposing natural teeth

implants

If the implant-to-abutment interface consists of a permanent extension on the top of an implant and a receptacle inside the abutment, the implant con nection is categorized as:

• an internal connection

• an external connection

• a cone in a socket connection

• a nonengaging connection

• a rotational element

Patients having complete dentures supported by soft tissue only tend to apply about one- sixth of the occlusal force compared to the fully dentate occlusion or a complete denture opposing natural dentition. Occlusal forces produced by full arch dentures supported by imrjlants produce about the same force as fully dentate occlusal schemes.

• an external connection

The junction of the abutment and the implant is important from an engineering standpoint and a biological standpoint. The restorative platform of the implant forms an interface, or a joint with the abutment. Ttysaxea is also referred to as the microgap. The precision of the fit between these components influences how much movement will occur between these parts ajnd how well the associated screws will remain tightened over time. Pre cision fit,N,fnternaI or external connection, andlntirotational elements are part of this junction and all require close manufacturing tolerances.

The closeness of the fit of the components plays a significant role in how much bacter ial contamination occurs at the interface. The term "microgap" emphasizes the space be tween the components and the space available for bacterial growth and the resultant inflammation at the location. Achieving a precise fit of these parts is unlikely if the abut ment is cast in the laboratory rather than milled by the manufacturer. Minimizing bacte rial contamination at this site influences how stable the bone will remain over time.

Jhe healing reaction of thejbone surrounding the mierogap is determined by the Tnacrostructure of the implant~me precision of the fit, ancnhe location of the microgap. Bone remodels and adapts to different configurations and locations of the interface dur ing the first year after placement of a restoration, and a characteristic bony shape is es tablished by that time. Following that time of initial bone remodeling, a very small amount of bone loss should then be noticeable over time, approximately 0.02 mm per year. Which of the following is/are necessary for osseointegration to be successful:

• primary stability of the implant

• limited micromotion during healing

• minimization of surgical trauma

• uncontaminated implant surfaces

• all of the above

implants

Osseointegration can fail due to:

• occlusal overload

• bacterial plaque

• micromotion during healing

• excessive cantilevering of the prosthesis

• all of the above

At the completion of surgical placement of an implant, the implant must not be movable in the osteotomy. This condition is termed "primary stability of the implant." If the im plant is not protected from excessive forces during healing (e.g., occlusion), the implant experiences movement relative to the surrounding bone. If this "relative motion" or "mi cromotion" persists, osseointegration will be prevented.

Surgical trauma can prevent the formation of osseointegration by damage to bone cells, often because of excessive heat generated during drilling procedures. Sharp burs, inter mittent drilling pressures, and irrigation for cooling of the burs and site can prevent or limit this injury to the bone. The limit of heat is 47 degrees C for less than 1 minute.

The implant is sterilized by the manufacturer and protected with packaging to preserve the oxide layer (T102) which is a passivation layer and critical for osseointegration. These conditions must be maintained before the implant is placed into the osteotomy.

\ •-.-. *4 *% **i '%

• all of the above

The two most common causes of periimplantitis are considered to be*plaque anrrtjc- clusal overload. Excessive cantilevering of an implant-borne prosthesis will result in excessive occlusal force on the implant as well as off-axis loading. Occlusal forces that are within the long axis of the implant are best tolerated by implants. Lateral forces are not as well tolerated and can be harmful if excessive. Lateral forces on implants magnify the amount of stress on the crestal bone surrounding the implant. "Off-axis loading of the implant is a term used to describe this situation."

Implants that have been judged to be a failure because of infection, bone loss, and/or mo bility must be removed. If an implant is mobile, it can probably be extracted fairly eas ily. If an implant needs to be removed but is not mobile, it is still osseointegrated to some degree. Extraction may be possible, with effort, or the implant must be removed with a special drill called a trephine drill. A trephine drill is a cylindrical, hollow, open-ended bur designed to fit over the implant and cut down the sides of the implant to release the implant from the bone. This may cause a significant amount of bone damage or bone loss, and a bone graft is sometimes placed following removal of the implant.

If an implant is judged to be unusable from a prosthetic standpoint (e.g., poor angulation or location) but is not otherwise failing, it may be covered with soft tissue and allowed to remain unused in the bone for an extended time. This is referred to as "sleeping" the implant. implants

"Antirotational" element is added to an implant to:

prevent rotation of multiunit restorations

• prevent rotation of the implant

• prevent rotation of the abutment in the implant

> prevent overtorquing of the abutment screw

^11 of the above

implants

"Site development" for implants includes the following techniques. Select all that apply.

• guided tissue regeneration

• socket grafting

• bone grafting with cow bone

• bisphosphonate supplementation for bone density

• orthodontic tooth movement

The antirotational element is designed to prevent rotation of the abutment, and thus.prevent loosening of the abutment screw that holds the abutment to the implant.

Antirotational elements between the implant and the abutment are described as "external" or "internal." The external type consists of a permanent extension from the implant that fits into a receptacle in the abutment. An "internal" antirotational element has the exten sion as a part of the abutment that fits into a receptacle in the implant.

Antirotational elements are also added to abutments to prevent the rotation of attached sin gle-unit restorations such as a single crown. Multiunit restorations do not require antiro tational features to prevent them from rotation on the abutment since they are connected to two or more implants or abutments.

%L\. ^V^

• guided tissuiee regenerregeneratioe n • socket grafting • bone grafting with cow bone • orthodontic tooth movement Bisphosphonates (e.g., alendronate) are used to treat osteoporosis and cancer. Bisphos phonate therapy, especially a history of IV bisphosphonate therapy, is one of the few ab solute contraindications for implant placement. BONJ, or bone osteonecrosis of the jaw, is a serious complication and is difficult to manage successfully. It can occur following dental surgery such as extractions and dental implant placement.

Guided tissue regeneration techniques have been adapted for bone augmentation in eden tulous areas, and the technique has become guided bone regeneration. Several bone graft materials and combinations of these materials are used in this procedure and are often covered with a protective "membrane." Bovine (cow) bone processed as a particu- late graft material is commonly used for oral bone grafting applications, including ridge augmentation and maxillary sinus augmentation or sinus "lifts." The bovine bone is clas sified as a xenograft, or bone that is transplanted to the recipient from a member of an other species. It can be combined with an autograft (or autogenous bone) from the recipient patient, or combined with bone from another human being (an allograft), or combined with a fabricated bone graft substitute material such as tricalcium phosphate or hydroxyapatite, which are forms of alloplasts.

Other site development techniques include orthodontic tooth movement to create space for implants. The tooth movement could include orthodontic extrusion of teeth to bring bone volume occlusally with the tooth, and thus increase bone volume at the site of the planned implant placement. z implants The hole that is surgically created in the bone to receive the implant body is called the:

• osteotomy

• bone channel

• smokestack

• callus core

• chimney

implants

A radiograpradio h should be exposed and interpreted at which of the following points during implant placement and restoration:

at the end of the surgical procedure

following the final torque application to an abutment

anytime the fit or seating of a component must be verified

intraoperatively to verify implant position

all of the above

The osteotomy is prepared with precision to make it the prescribed size that is appropri ate for the implant being used. If the osteotomy is too small, either in width or length, the implant may not go to depth or seat completely to the desired level in the bone. The over all implant shape (macrostructure) and the bone "quality" at any site dictate how the os teotomy must be prepared. If the bone is very dense and a screw-shaped implant is being used, the osteotomy may be "tapped" meaning that screw threads are created on the walls of the osteotomy to receive the screw threads on the implant. AJrill designed as a "thread tap" is used for this purpose. Many implants are designed to be "self-tapping," meaning that tapping of the bone as a separate step is not necessary because the threads of the im plant are designed to engage the bone and guide the implant forward.

If the osteotomy is too large for the implant diameter, or if the osteotomy is overprepared or poorly prepared, the implant will lack primary stability, an unacceptable result that will cause osseointegration to fail.

• all of the above

Radiographic verification that the desired anatomic placement of the implant or implants has been achieved is desirable at the completion of the surgery to make sure the implant and any vital structures nearby are separated as planned. Also, positioning of the im plants) from a prosthetic standpoint can be assessed and corrections made at this time if necessary. In addition, the surgeon should have documentation of the successful implant placement before the patient is dismissed. The surgical placement radiograph is an im portant baseline record that will be used for comparison at multiple time points during the life of the implant.

During the surgical procedure in which the implant(s) are placed, radiographs can be taken of depth gauges, the drills, the implant itself, or other markers to judge whether the proper depth or anatomic location has been achieved before further drilling or implant advance ment is accomplished.

After the final torque is applied to a long-term healing abutment, an impression coping (post), or the final restoration, verification of the proper mating of the components is nec essary. Impressions for fabrication of prostheses and the subsequent laboratory proce dures that rely on the impressions cannot be accomplished accurately if any of the components are not joined together completely, also referred to as being "down." Inac curacy during the fabrication of a restoration will prevent the prosthesis from fitting pas sively to all of the implants involved. This nonpassive fit can lead to implant failure. implants

The most common source of patient dissatisfaction with implants is:

• pain

• appearance

• mobility

• loss of osseointegration

implants

Which of the following was/were included in the 1986 Albrektsson et al crite ria for functional implant success?

• implant is immobile and has no periimplant radiolucency

• bone loss is less than 0.02 mm/year after the first year of service

• absence of persistent and/or irreversible pain, infection, paresthesia or violation of the mandibular canal

• success rates of at least 85% at year 5 and 80% at year 10

• all of the above

Implants have become very predictable and successful from a functional standpoint, and failure of implants due to loss of osseointegration is not common. Satisfying patient ex pectations of esthetic outcomes is a most difficult aspect of implant treatment since restoration of bone, gingival contours, and papillae is sometimes not possible. Absence of a papilla between adjacent implants is a common problem, and for this reason, it may be advantageous to avoid placing adjacent implants, if possible.

Note: "Black triangle disease" refers to an absence of one or more papillae, which cre ates an esthetic concern.

• all of the above

This set of criteria is often quoted to help define or determine whether or not an implant is successful.

Implant mobility indicates loss of osseointegration and implant failure. Implants with only partial loss of osseointegration will still be stable. A periimplant radiolucency in dicates that bone is not in contact with the implant, and it suggests loss of osseointegra tion. A periimplant radiolucency often has the appearance of a distinctly widened periodontal ligament on a natural tooth. Persistent pain, infection, or paresthesias are not normal implant outcomes and indicate definite complications of implant placement. A radiographic appearance of violation of the mandibular canal by an implant could be misleading and would not, by itself, define failure. Radiographic confirmation of the im plant malposition, particularly in combination with persistent pain, infection, or pares thesia, would mean failure. Success rates are generally higher than 80% to 85% today, with 95% and higher being expected.

% XX n CXo X "' implants

"Direct structural and functional < :onnecti<> n between ordered, living bone and the surface of a load-carrying implant" is the definition of:

• a cold weld

• ankylosis

• osseointegration

• metal callous formation

Implants should not be treatment planned in young individuals until skeletal growth has been completed.

•true

• false

Osseointegration means direct bone-to-implant contact with no intervening periodontal ligament or any other tissue. There is no insertion of connective tissue fibers into tita-' nium, meaning there cannot be a functional periodontal ligament. Connective tissue pres ence around an implant means failure of osseointegration and implant failure. Epithelium does attach to titanium via a "junctional epithelium" structure comprised of hemidesmo somes and a basal lamina. Titanium is usually covered by an oxide (Ti02) that is biolog ically inert and prevents host tissue access directly to titanium itself and allows osseointegration.

At the light microscopy level, there is an intimate association of bone to the titanium. Within a few weeks of placement of the implant, woven bone is laid down at the bone- implant interface. Wav.£rxJbone is characterized by a very random orientation of its colla gen fibrils, and it is the first bone to be established on the implant. Within a few more weeks, the woven bone becomes lamellar bone. The conversion to lamellar bone is thought to be encouraged by the presence of functional forces placed on the implant to stimulate the bone. Roughened implant surfaces, such as those created by sandblasting and acid etching, etc., encourage and accelerate the bone formation at the titanium surface.

• true

Implants are essentially ankylosed structures and do not erupt or move physiologically within bone. If the growth of the individual has not been completed, the original posi tioning of the implant in the jaws may become increasingly unfavorable due to changed shape or size of the surrounding tissues. Early successful esthetic outcomes can be lost. The implant may also prevent normal development of the jaws. implants

The highest rate of implant failure occurs in:

• type 1 bone

• type 2 bone

• type 3 bone

• type 4 bone

61 copyright £)2013-2014-Denta l Decks PERIODONTICS

implants

In patients with normal bone and normal healing capabilities, one should an- ticipate dental implant success rates of:

• 35%

• 50% to 60%

• 74%

• 90% to 95%

• 100%

?one quality is categorized according to its cortical plate thickness and cancellous/tra becular density. The thicker the cortical plate and the higher the cancellou!lIensnEy7me hig^eTffie"quaTity of the bone in terms of implant stability and support. Type 1 bone is the best quality and most suitable for retention of implants.

Type I bone occurs in the anterior mandible, for example, where the bone is mostly cor tical bone. Type 2 bone is a thick layer of cortical bone and the cancellous bone core is most dense. Type 3 bone is composed of a thin layer of cortical bone surrounding a dense core of cancellous bone. Type 4 bone is characteristic of the posterior maxilla and has a typically thin cortical plate and low density cancellous bone core, and thus is the least well suited to promoting osseointegration and supporting occlusal loads.

The risk of implant failure is higher than normal in: N^Cigarette smokers VPoorer "quality" bone s»*The maxilla than in the mandible ^^Individuals with uncontrolled diabetes

Risk factors for implant failure or complications include metabolic diseases that can in fluence systemic healing.sJJticontrolled diabetes is one of these conditions as are bone metabolic diseases.^hjstory of head and neck radiation therapy, and^paunosuppressive medications. Implant failures are recognized to be more frequent in smokers. Failure rates are highest where the bone is of the poorest quality, such as D4 bone quality bone in the posterior maxilla.

• 90% to 95%

In patients with normal healing capabilities, especially good bone healing capabilities, and sufficient bone of good quality, implant success rates are often quoted in the range of 90% to 95%.

Diminished healing capacity would possibly be encountered in patients with uncontrolled or poorly controlled diabetes mellitus, immunocompromised states, radiation treatments, and chemotherapy. Patients with well-controlled diabetes do not have compromised implant out comes. Patients with a diminished capacity for fighting infection could be expected to expe rience problems with oral surgical procedures, including implants.

Smoking is not a contraindication for the placement of dental implants, however, failure rates are higher in smokers. The failure rate is related to the amount of smoking on a daily basis and the pack/years history for the patient.

Remember: Implants should not be considered for children who are still experiencing growth.

Note: Implant failures are generally considered to be "early," meaning soon after surgical placement and before prosthetic loading, or "late," meaning after an extended period of time following placement of the prosthetic restoration on the implant. Early failures are related to sujgical, trauma and/or ipaplant instability at the time of placement. Late failures are most often related to microbial plaque accumulation equivalent to periodontal disease and/or to excessive occlusal forces.

"Periimplant mucositis" denotes inflammation of the soft tissues surrounding the implant but wWE"f5crlWrW,bMle"''e^eriimpIantitisj' refers to this inflammation but with accompanying loss of implant-supporting bone. Both conditions require treatment. implants

Implants are useful for orthodontic anchorage because implants:

• do not move in response to orthodontic forces

• do not have a periodontal ligament

• can be placed and later removed

• can be located to gain force advantage

• all of the above

implants

The greatest esthetic challenge for the restorative dentist occurs in the patient having a:

high smile line, thick periodontal biotype

low smile line, thin periodontal biotype

low smile line, thick periodontal biotype

high smile line, thin periodontal biotype

Implants do not move in response to orthodontic forces because they do not have a periodontal ligament. Thus, bone cannot be resorbed and replaced at the bone-implant interface, such as around teeth, to make implant movement possible. Certain types of im plants can conveniently be placed for anchorage on a temporary basis and then removed later following completion of the orthodontic treatment.

The periodontal ligament is responsible for proprioception around natural teeth. The lack of the periodontal ligament around implants results in a much reduced tactile sense of where the implants are in relation to the opposing occlusion. There is a phenomenon that develops with time called osseoperception, which gives the patient a certain amount of tactile sense regarding the implants in the bone.

• high smile line, thin periodontal biotype

A low smile line indicates that the patient does not lift the lip upward when smiling to the extent that the gingival-restorative interface can be seen by the observer. Consequently, esthetic compromises may be more acceptable to the patient because they are not rou tinely visible. A thick periodontal biotype indicates that the patient has thicker, denser gingiva with a less pronounced scallop. This type of tissue is more resistant to recession caused by restorative procedures and materials, a lower chance of "show through" of the implant or abutment and a lower chance of loss of the papillae adjacent to the implant.

Abutments can be made from metal or ceramic materials. Aluminum oxide and zirconium ceramic abutments can be fabricated by CAD/CAM (Computer Aided Design/Computed Aided Manufacture) methods and milled by machine. Ceramic abutments may be more subject to fracture than titanium or other metal abutments under heavy occlusal loads. implants

The "anterior loop" is descriptive of the:

• circular course of the internal maxillary artery

• maxillary sinus extension toward the canine tooth

• course of the inferior alveolar nerve anterior to the mental foramen

• necessity for angled abutments

• none of the above

implants

Assessment of the potential implant patient should include:

• direct palpation of the bony ridges

• determination of any limitations of mouth opening

• cross-sectional imaging

• all of the above

When treatment planning mandibular implant locations, the possibility that the inferior alveolar nerve courses anterior to the mental foramen by as much as 4 mm before loop ing back distally to exit through the mental foramen must be considered. If imaging data does not clearly identify the canal of the inferior alveolar nerve as it approaches the men tal foramen, the implant location should be planned to be at least 5 mm or more anterior to the foramen.

The inferior alveolar nerve also courses from lingual to buccal as it moves anteriorly. When planning implant position, the osteotomy preparation should be planned to end a minimum of 2 mm vertically away from the mandibular canal, and 2mm away from any other vital structure.

• all of the above

The assessment of the prospective implant patient should include direct palpation of the bone contours in the area of the planned implant to judge for adequate bone volume. It is particularly important that the lingual contours of the mandible and any possible concav ities, such as the submandibular fossa, be explored since surgical encroachment on such areas can lead to life-threatening complications for the patient.

Cross-sectional imaging is not absolutely required, but it is far superior to two-dimen sional radiography and will be considered the standard of care in many locations. De fense of the omission of cross-sectional imaging analysis would seem difficult in the event of a surgical complication.

Limitations of any mouth opening ability on the part of the patient can preclude placement of an implant due to the inability to accommodate the handpiece and drills. implants

The "anterior loop" is descriptive of the:

• circular course of the internal maxillary artery

• maxillary sinus extension toward the canine tooth

• course of the inferior alveolar nerve anterior to the mental foramen

• necessity for angled abutments

• none of the above

implants

Assessment of the potential implant patient should include:

• direct palpation of the bony ridges

• determination of any limitations of mouth opening

• cross-sectional imaging

• all of the above

Limitations of any mouth opening ability on the part of the patient can preclude placement of an implant due to the inability to accommodate the handpiece and drills. implants

Where should the healing abutment be placed at the stage II (uncovering) sur gery for a two-piece implant system? Select all that apply.

• approximately 1 to 2 mm "taller"then the height of the tissue

• out of occlusion

• radiographicallyconfirmed as seated

• designed to shape or mold the tissue

implants

At the conclusion of surgical placement of a titanium implant, complete soft tissue coverage of the implant is required for successful osseointegration to occur.

true

false

67 copyright © 2013-2014 - Dental Decks PERIODONTICS • approximately 1 to 2 mm "taller" than the height of the tissue • out of occlusion • radiographically confirmed as seated • designed to shape or mold the tissue

It is possible for an implant that was surgically placed with primary stability and given ad equate time to osseointegrate can subsequently be found to rotate in the osteotomy at the time of the second, stage surgery. This rotation is sometimes detected when the healing abutment is attached to or torqued onto the implant. Although mobility of an implant is considered a sign of implant failure in other circumstances, the rotation of the implant at second, stage surgery may possibly be overcome by replacing the cover screw, covering the implant with soft tissue, and allowing the site to heal for an additional 3 months. The implant is taken completely out of function for this time.

This concept was adhered to in the early techniques for surgical placement of two-piece (or two-stage, or "submerged") implant systems. Two-piece systems typically involve initial osseous placement of the implant and coverage with primary closure of the gingi val flaps.

Current surgical placement techniques for two-piece systems also include leaving the at tached abutment exposed to the oral cavity at the time of implant placement. One-piece systems (also called one-stage or nonsubmerged systems) are typically placed with the im plant exposed to the oral cavity, also called "transgingival" placement. IIIIIIIIIII mi ..ijij.uiiwuj.il n ""' inww »nm i JUMJJIIJIJJ

A "radiographic stenf'or guide: • Identifies proposed implant sites in the radiograph • Positions opaque markers in the radiograph • Correlates information on the radiographs, cast, and wax-up • Can help identify distortion in the radiograph implants

The clinical examination of osseointegrated dental implants should include:

soft tissue observation

• radiographic assessment

• probing

• visual inspection of implant components

• all of the above

implants Cross-sectional imaging is produced by all of the following EXCEPT one. Which one is the EXCEPTION!

• cone beam computed tomography

• panoramic radiography

conventional linear tomography

• computed tomography scans

Tissue observation around implants is based on many of the same parameters that are used when assessing natural teeth. Bleeding on probing or absence of bleeding on prob ing are useful indicators of inflammation. Purulence, edema, erythema, and loss of at tachment can be used to assess soft tissue health. Probing depths are generally deeper than around teeth and can be difficult, to interpret due to surgical variability. Deeper prob ing depths tend to harbor a more pathogenic flora. Probing depths can be difficult to meas ure due to the size and access limitations of implant restorations. Changes in attachment level around an implant are useful in recognizing progression of periimplantitis.

Remember: The term "relative attachment level' is used when the attachment is calculated from a landmark beside the CEJ.

Important: The use of plastic probes has been widely recommended to avoid scratch ing of titanium components.

• panoramic radiography

Cone beam computed tomography (CBCT) is a 3-dimensional imaging modality that produces digital data that can be reformatted to produce multiple cross-sectional slices and other views of the jaws. CBCT exposes the patient to a relatively low dose of radiation when compared to medical-grade CT. "Cat Scan" refers to CT. Conventional linear tomography utilizes a radiation source and an x-ray film which rotate in tandem around a single point to produce a cross-sectional view left over after everything else is blurred out in the image. Image quality of linear tomography is of significantly lower quality than CBCT.

Advantages and Disadvantages of Various Radiographic Projections* Modality Advantages Disadvantages

Periapical and occlusal High resolution and detail, easy Unpredictable magnification, small imaged area, 2D radiography acquisition, low exposure, representation of anatomy inexpensive Panoramic radiography Easy to acquire, images whole Unpredictable magnification, 2D representation of ridge, low exposure, inexpensive anatomy, not detailed Lateral cephalometric Easy to acquire, predictable Limited use in area of midline, 2D representation of radiography magnification, low exposure, anatomy inexpensive ..Conventiona l 3D representation, predictable Requires special equipment; for evaluation of multiple tomography magnification, sufficient detail, sites, can be a lengthy procedure because patient must low exposure, images area of in be repositioned for each site; blurring of image may terest only occur depending on adjacent structures; expensive

VCompute d tomography 3D representation, predictable Requires special equipment, expensive, high exposure (CT) magnification, sufficient detail, dose, images whole arch digital format, images whole arch ' •<5one-beam computed 3D representation, predictable Requires special equipment, expensive, images whole tomography (CBCT) magnification, sufficient detail, arch digital format, images whole arch, low dose implants

Of the following factors, which determine(s) the abutment that the restorative dentist should select?

• soft tissue (mucosal or gingival) height

• interarch space

• implant angulation

• esthetic requirements

• all of the above

implants

Which of the following dimensions is not part of routinely recommended space requirements for root form implants?

a minimum of 3 mm of space between adjacent implants

• at least 2 mm of bone remaining between the implant and vital structures

> at least 1 mm of bone surrounding the implant in all dimensions

• a minimum of 16 mm of implant length for stability

• placement of the restorative platform apical to the CEJ's of adjacent teeth

71 copyright O 2013-2014 - Dental Decks PERIODONTICS • all of the above

Ideally, the abutment type is selected during the treatment planning process for the implant and restoration. "Stock" abutments (made in standard sizes) can be selected to accom modate a cemented or a screw-retained restoration. Abutments can be used to compensate for an implant angulation that must be different from the desired restoration angulation or position. The abutment should be long enough to provide adequate retention, but short enough to allow the combined abutment and restoration to fit into the space available be tween the occlusal aspect of the implant and the opposing occlusion. This space is referred to as the "interarch space" or "restorative space." Different material compositions of abutments can be selected for optimum color effect.

• a minimum of 16 mm of implant length for stability

Implants of 10 to 14 mm length are routinely used successfully and achieve adequate primary stability. Implanrs with 16 mm of available bone height (plus a 2 mm margin of safety from adjacent vital structures) are not usually available or required. Implants of 10 mm implants are generally considered the minimum recommended length, although 8 mm and shorter implants are available.

The term "vital structure" refers to any structure that the surgeon should avoid contact ing during implant placement (e.g., the inferior alveolar nerve, the maxillary sinus, roots of nearby teeth and blood vessels, especially on the lingual aspect of the mandible). A 2 mm margin of safety is usually allowed between the limit of the osteotomy and any vital stractureJL.ess than 3 mm of bone between adjacent implants risks bone loss in the area and esthetic consequences.

Primary stability is a primary objective at surgical placement of the implant. It depends on the overall sljape or geometry of the implant, including the presence of threads, the pre cision of the osteotomy preparation, and the quality of the bone at the site. For the implant ^to achieve osseointegration, primary stability must be achieved at the time of surgical placement. implants

A "polished collar," or the smooth polished exterior surface of the implant closest to or in the oral cavity, is designed to: "•:: : •

• provide a location for epithelial attachment

• make the exposed surface cleansable

• keep plaque from gaining access to deeper structures

• inhibit biofilm formation

• all of the above

74 copyright CS2013-2014-Denta l Decks PERIODONTICS

implants

A "Morse taper" is one of many designs for:

• the abutment to implant connection

• the shape of the abutment's restorative part

• press-fit implants

• threads on a screw implant

• an implant milling machine

73 copyright e 2013-2014- Dental Decks PERIODONTICS • all of the above

The soft tissue interface can be keratinized gingiva or nonkeratinized mucosa, both seem clinically acceptable. In early implant designs, it was thought that the polished sur face of the collar would allow for an epithelial attachment that would keep plaque from reaching the nonpolished or roughened surface in the bone. Plaque is less likely to form on a smooth surface than on a rough surface. Epithelium can also form an attachment on a roughened surface.

Remember: The interface between epithelial cells and titanium is composed of hemidesmosomes and a basal lamina. The epithelial attachment is identical to a natural tooth, with a long junctional epithelial attachment. A sulcus forms lined by sulcular ep ithelium which then transitions into oral epithelium

Note: Interposed between the epithelial attachment and the marginal bone is a dense zone of connective tissue with a somewhat limited vascularity.

• the abutment to implant connection

A Morse taper is a cone-in-socket type of connection design for the fitting of the abut ment into the implant. As the cone is forced (tightened) into the socket, the connection be comes increasingly tight and resistant to movement of the abutment. This stability can be incorporated as an antirotational element to keep the abutment from rotating in the im plant. The cone-in-socket fit can also produce a very close joining of the metal compo nents, which inhibits bacterial contamination of the joint. implants Which of the following is NOT acceptable for cleaning of titanium surfaces, either by the patient or the dental clinician?

• powered toothbrushes

• end-tufted brushes

• plastic curettes

• conventional ultrasonic tips

• floss, especially multifilament varieties

76 copyright e 2013-2014 - Dental Decks PERIODONTICS

implants

If the space available for the abutment and the crown is limited vertically, i.e., a small interarch space, which of the following abutment combinations would be least advantageous:

• cemented crown to the abutment

• screw-retained crown on the abutment

• restoration that fits to the implant with no abutment

• abutment with a ball extension for a removable prosthesis

Titanium as a metal is relatively "soft" and can be scratched on the surface fairly easily. Plas tic curettes, rather than metal curettes, are recommended for titanium surfaces on implants and abutments, particularly subgingivally. The same applies in the case of plastic periodontal probes instead of metal probes on titanium. Powered toothbrushes have been shown to be ac ceptable on titanium surfaces. Floss is not harmful to titanium surfaces, nor are conventional toothbrushes and end-tufted brushes. Conventional metal ultrasonic tips should not be used because they do significant damage to titanium components. However, specially designed ultrasonic tips having plastic or other softer coatings are available, and these are acceptable. The underlying principle is that whatever is selected to clean titanium surfaces must not scratch or pit those surfaces. All of the following products can be used on implants and other titanium surfaces: ^yfJhlorhexidine mouth rinses ^Phenolic compound mouth rinses ^-Water jet irrigators \WPvubber cup polishing with fine pumice The reaction to plaque by the tissues surrounding an implant is very much like the tissue re action to plaque by the tissues around teeth. Implant maintenance is based on the principles of periodontal maintenance, and patients are thus instructed in cleaning methods to personally remove plaque on a consistent basis. Patients are also advised to return for cleaning of the sur faces of the implant system that are exposed to the oral environment. Titanium surfaces are subject to the formation of plaque and calculus. A suggested interval for implant maintenance appointments is every 3 months for cleaning of the surfaces and inspection of the parts of the system which can become loose with function. Periimplantitis can form around implants in response to plaque. This process is very similar to that of periodontitis with many of the same organisms involved in etiology.

This combination would take up the greatest amount of space vertically due to the re quirements for adequate abutment length needed to provide retention for the cemented sur faces Screw-retained combinations can be shorter and take up less space, the same being true for restorations designed to fit directly to the implant with no intervening abutment. "Platform switching" refers to

• replacing the implant to get a better abutment selection

• changing to a wider abutment for molar contours

• changing to a shorter abutment to hide margins

• matching a smaller diameter abutment with a wider diameter implant

• converting a round abutment to triangular

implants

Which of the following conditions is not a contraindication to dental implant placement?

• current chemotherapy for the treatment of cancer

• history of radiation therapy to the maxillofacial complex

• dysmorphophobia

• advanced patient age

77 copyright a 2013-2014 - Dental Decks PERIODONTICS • matching a smaller diameter abutment with a wider diameter implant

Platform switching refers to combining an abutment of a particular diameter with a non- matching diameter implant. Typically, this is a smaller diameter abutment connected to a larger diameter implant. This combination is advantageous in terms of reducing the amount of bone remodeling and bone loss that normally occursjollowing placement of the abutment and the restoration on the implant.

Different designs of implants have typical patterns of bone remodeling following final placement of the abutment. The physical location and the design of the abutment to im plant connection play a role in localization of inflammation in the adjacent bone and the remodeling outcome. This connection has commonly been in the form of a butt joint be tween an abutment and an implant of the same diameter. This physical combination, even under the best circumstances, allows some degree of bacterial activity between the com ponents, and if this abutment-to-implant interface (or "microgap") is located at or under the bone crest, increased bone loss or remodeling can occur. By combining the smaller di ameter abutment with the larger diameter implant, this interface is moved slightly away from the bone, resulting in less crestal bone remodeling.

• advanced patient age

Advanced patient age is not a contraindication to implant treatment. The ability of the patient to withstand surgical treatment, etc. is a decision resting on the systemic health of the patient.

Any condition that causes an impairment of the patient's ability to heal should be con sidered as a contraindication to implant treatment. Serious psychiatric, conditions, such as psychoses, should be considered a contraindication to implant treatment. Dysmorpho- phobia is an extremely irrational fear of being disfigured by treatment. Psychiatric com plications can make the patient change his or her opinion about the acceptability of treatment, which is difficult for the clinician to overcome.

Remember: Smoking is not a contraindication for the placement of dental implants, how ever, failure rates are higher in smokers. infl

Which cells control all three stages of inflammation?

• plasma cells

red blood cells

• leukocytes

• Sertoli cells

implants

If two adjacent implants are surgically placed too close together:

• the patient will have difficulty cleaning the area

• bone loss will probably occur between the implants

• the presence of a normal papilla is unlikely

• optimum esthetic contours will be prevented

• all of the above

79 copyright © 2013-2014 - Dental Decks PERIODONTICS Inflammation is an observable alteration in tissues associated with changes in vascular per meability and dilation, often with the infiltration of leukocytes into affected tissues. These changes result in erythema, edema, heat, pain, and loss of function that are the "cardinal signs" of inflammation. Typical inflammation can progress through three stages: • Immediate • Acute *** Leukocytes, the white blood cells, control all three stages • Chronic Leukocytes originate in the bone marrow and exit from the blood by transendothelial migra tion under normal conditions, accounting for the resident leukocytes found in tissues. Among the most important resident leukocytes are mast cells, peripheral dendritic cells, and monocyte derivatives such as dermal dendrocytes (histiocytes). These resident leukocytes transmit in formation that initiates the process of immediate inflammation. Immediate inflammation is followed within minutes by a short-lived period (up to several hours) of acute inflammation that is characterized by an influx of neutrophils to the area after they exit the blood. If the problem is not resolved, acute inflammation gives way to a poten tially unending period of chronic inflammation dominated by the migration of lymphocytes and macrophages to the local tissues. Note: Cells of the immune system that are important in inflammation and host defenses include mast cells, dermal dendrocytes (histiocytes), peripheral dendritic cells, neutrophils, mono cytes/macrophages, T cells, B cells, plasma cells, and natural killer (NK) cells. Remember: Mast cells, dendritic cells, neutrophils, and monocytes/macrophages are consid ered to be cells of the innate immune response (from birth). Lymphocytes (T cells, B cells, and plasma cells) are considered to be part of the specific immune response and develop antigen- specific responses throughout life.

• all of the above

When adjacent implants are treatment planned, there should be sufficient space for a min imum of 3 mm of bone remaining between the implants. This distance will prevent or limit the amount of bone loss that occurs between the implants during the normal osseous remodeling that occurs after abutment placement. If the implants are closer than 3 mm, bone loss is likely as the two remodeling processes coalesce. In addition, if subsequent bone loss occurs due to periimplantitis on one of the implants, this can affect the bone on the adjacent implant if they are too close together. The amount of space required to suc cessfully position, restore, and maintain the implant(s) must be calculated with the planned implant diameters considered. If adjacent implants are too close to one another, oral hy giene efforts by the patient are compromised due to lack of access for hygiene meas ures. Periimplantitis can result.

Maintaining or creating an esthetic papilla between two adjacent implants is a major chal lenge, and bone loss between the implants makes formation of a full papilla even more un likely. An unesthetic open space can easily result and is commonly referred to as a "black triangle." The shape of the matured new papilla depends on the distance between the im plants, the bone remaining, the depth of the implant placement, and the shape of the restorations. Vertically, only 2, 3, or 4 mm of soft tissue height can be expected to form between two implants.

Implant placement adjacent to a natural tooth should allow a minimum of 1.5 mm of re maining bone between the implant and the tooth. To allow for an esthetic emergence pro file, an implant should be surgically positioned 2 to 3 mm apical, to the adjacent tooth CEJ. The presence of a papilla between the implant and the natural tooth is largely depends on the bone level remaining on the natural tooth, o^/" - infl

Which cells of the immune system possess receptors for the complement component C3a, by which they participate in immediate inflammation?

• peripheral dendritic cells

• dermal dendrocytes (histiocytes)

• monocytes

• natural killer (NK) cells

82 copyright O 2013-2014 - Dental Decks PERIODONTICS

infl

Initially, the first group of cells to arrive at the site of injury are neutrophils. Later, become more numerous. In certain parasitic infections, predominate. In viral infection, rather than neutrophils usually predominate.

• plasma cells, basophils, eosinophils

• macrophages, eosinophils, lymphocytes

• macrophages, lymphocytes, basophils

• lymphocytes, macrophages, eosinophils

81 copyright

~~macrophages, eosinophils, lymphocytes~~

Stages of Acute Inflammation: : 1. Vascular Phase of Inflammation' • Vasoconstriction - Immediately •followin • "• g tissue injury, there is a brief period of localized vasoconstrict ion. • Complement activation and mediator release - Tissue injury, or the presence of bacteria, activates com plement. C3b molecules formed in this process bind to microbes and injured tissue (opsonizationLCia and C5a (chemptgxms) trigger the release of histamine and s,erotonin from nearby mast cells. Tissue injuryalsb triggers the formation of bradykinin and initiates the synthesis of prostaglandins and leukotrienes. • Vasodilation - Histamine' and the other vasoactive mediators of inflammation, then cause relaxation of smooth muscle in arteriolar and capillary walls. Vessels dilate, which increase blood flow to injured tissues. This is manifested by redness (hyperemia) and heat near the site of injury. • Increased vascular permeability - With vasodilation, the endothelial cells lining blood vessels contract slightly, creating gaps between the cells that allow plasma to escape into surrounding tissues. Plasma d livers antibodies and other antimicrobial substances to the site of injury. Fibrinogen from plasma also clots and serves as a temporary barrier to bacterial invasion. 2. Cellular Phase of Inflammation] • Adhesion - As blood vessels dilate, the velocity of blood flow slows allowing circulating white blood cells to accumulate on the inner surface of vessel walls. This process is called margination. • Diapedesis and chemotaxis - The WBCs, then begin to squeeze between the contracted endothelial cells and migrate in an ameba-like fashion into the extravascular space (aprocess called diapedesis). Once in tis sue, the WBCs are attracted by activated complement and and begin to migrate the site of injury or infec tion. WBCs (specifically PMNs) apparently have surface receptors for chemotactic agents (i.e., C5a,TNF. IL-8 LtBst IL-1 IFN-s) which cause them to move in the direction of increasing concentrations of the chemotactic substance (process is called chemotaxis). Initially, the first group ot cells to arrive at the site of injury are neutrophils (PMNs). Later, macrophages become more numerous. In certain parasitic infec tions, eosinophils predominate. In viral infection, lymphocytes rather than neutrophils usually predominate. • Phagocytosis - When WBCs (specifically PMNs) arrive at the site of tissue injury or microbial invasion they become very active and begin engulfing bacteria, forming a phagosome that combines with lysosomal granules to form a phagolysosome in which digestion of the engulfed particle occurs. infl

The . has emerged as a unique immune cell that could be activated by many nonimmune processes, including acute stress, and could participate in a variety of inflammatory diseases in the nervous system, skin, joints, as well as cardiopulmonary, intestinal, and urinary systems.

~~• neutrophil~~

~~• epithelioid cell~~

~~• mast cell~~

~~• eosinophil~~

~~infl~~

~~The main cells involved in chronic infection are lymphocytes and:~~

~~• plasma cells~~

~~• mast cells~~

~~• neutrophils~~

~~• macrophages~~

Mast cells originate from pluripotent cells. The mast cells enter the bloodstream, migrate throughout the body, and mature. They frequently locate at perivascular sites in tissues, such as the lungs, where they interact with the external environment.

Mast cells become activated when surface receptor-bound antigen-specific immunoglob ulin E (IgE) encounters an antigen that the IgE recognizes. This triggers mast cell degranulation, leading to the rapid release of inflammatory mediators, such as^JjUtamine, jjpeteoglycans, andcjrtokines. Mast cell activation also stimulates the arrival of other in flammatory cells — a critical step in local inflammation.

Mast cells are not only necessary for allergic reactions, but recent findings indicate that they are also involved in a variety of neuroinflammatory diseases, especially those wors ened by stress. In these cases, mast cells appear to be activated through their Fc receptors by immunoglobulins other than IgE, as well as by anaphylatoxins, neuropeptides, and cy tokines to secrete mediators selectively without overt degranulation.

1. The mast cell content in human gingiva is high. The mast cell content of in- Notcs flamed gingiva increases as the severity of inflammation increases. 2. Remember:The anaphylactic response is characterized by the degranulation of mast cells as a result of antigen-antibody complexes affixed to cell surfaces.

~~• macrophages~~

Inflammation that has a slow onset and persists for weeks or more is classified as being chronic. The symptoms are not as severe as with acute inflammation, but the condition is insidious and persistent. The main cells involved in chronic infection are macrophages and lymphocytes. With the aid of chemical mediators, such as lymphokines, macrophages do an excellent job of engulfing and neutralizing or killing foreign antigens. Lymphocytes are the predominant cell in chronic inflammation. Note: Macrophages and lymphocytes are interdependent in that the activation of one stimulates the actions of the other.

Chronic inflammation: • Lymphocyte, macrophage, and plasma cell infiltration • Tissue destruction by inflammatory cells • Attempts at repair with fibrosis and angiogenesis (new vessel formation) • When acute phase cannot be resolved - Persistent injury or infection (ulcer, TB) - Prolonged toxic agent exposure (silica) - Autoimmune disease states (RA, SLE) • Macrophages • Scattered all over (microglia, Kupffer cells, sinus histiocytes, alveolar macrophages, etc.) • Circulate as monocytes and reach site of injury within 24 to 48 hrs and transform • Become activated by T cell-derived cytokines, endotoxins, and other products of inflammation • T and B lymphocytes • Antigen-activated (via macrophages and dendritic cells) • Release macrophage-activating cytokines (in turn, macrophages release lymphocyte-activating cytokines until inflammatory stimulus is removed)

• Plasma cells • Terminally differentiated B cells • Produce antibodies • Eosinophils • Found especially at sites of parasitic infection or at allergic (IgE-mediated) sites misc. Which one of the following will increase the abrasive action of a polishing agent? Select all that apply.

~~• using an agent with nice large particles~~

~~• using an agent containing particles that are dull and round~~

~~• using a thick, viscous mixture of polishing paste~~

~~• applying the polishing agent with firm pressure and increasing to a heavy constant pressure~~

~~• polishing at a low speed with light pressure~~

~~misc.~~

~~The purposes of periodontal dressings (packs) include all of the following: 2&C&»{Jt -•>~~

~~• stop persistent bleeding~~

~~• maintain the sutured position of the flaps~~

~~• improve patient comfort~~

~~• prevent mechanical injury to healing tissues~~

85 copyright 0 2013-2014 - Dental Decks PERIODONTICS • using an agent with nice large particles • using a thick, viscous mixture of polishing paste • applying the polishing agent with firm pressure and increasing to a heavy constant pressure

*** Using a thin, watery mixture of polishing paste, using an agent containing particles that are dull and round, or polishing at a low speed with light pressure will reduce the abrasive action of a polishing agent.

The use of abrasive polishing agents and/or a rotary polishing instrument may be con traindicated in the following cases: • Patient with a communicable disease: the production of aerosols is likely to occur, which may disseminate the disease • Patient with respiratory problems • Patient with "green stain": usually the tooth surface under the stain is demineralized • Patient with newly erupted teeth: have not mineralized completely yet • Any patient who is at increased risk for dental caries: those with xerostomia, amelogen esis imperfecta, rampant caries, or receiving radiation therapy to the head

*** -pjjg uge 0f a porte-polisher (manual polisher) may be helpful in some of the cases listed above. *** Dental tape and finishing strips may be used to polish interproximal tooth surfaces.

1. When selecting a polishing agent to remove generalized staining, consider the foi ls otes lowing: tooth sensitivity, type of stain present, type of restorations present, and the condition of the tooth surface. *** Not all surfaces should be polished. 2. Flexing the polishing cup into proximal areas increases its effectiveness.

• stop persistent bleeding (all bleeding should be controlled before the periodontal dressing is placed) Purposes of the periodontal dressing (periodontalpacks): • Provide mechanical protection for the surgical wound and, therefore, facilitate healing • Helps prevent postoperative bleeding by keeping the initial clot in place • Supports mobile teeth during healing • Mechanically maintains postsurgical position of the flaps • Helps in shaping or molding the newly formed tissue • Provide patient comfort by isolating area from external irritations or injuries Characteristics of acceptable dressing material: • Nontoxic or nonirritating to the tissue • Conveniently prepared, placed, and removed with minimal discomfort to patient • Should maintain adhesion to itself and to the teeth, kept in place mechanically by interlocking in in terdental spaces Types of Dressings (packs): usually contain zinc oxide and may be either eugenol- or noneugenol con taining. • Non-eugenol (soft pack) - 2 tubes: • one tube contains: Zinc oxide, an oil (forplasticity), a gamffbr cohesiveness), andlorot- hidol (a fungicide) • one tube contains liquid coconut fatty acids thickened with colophony resin (or rosin) and chlorothymol (a bacteriostatic agent) - Brand names: Coe-Pak *** most widely used in the United States. • Zinc oxide-Eugenol Packs: are supplied as a liquid (eugenol) and a powder (zinc oxide). 1. Periodontal dressings have no well-defined effect on the processes of wound healing or on Notes surgical outcomes (i.e., gains of periodontal attachment or the reduction in probing depths). 2. For first week postoperatively, patient should rinse with 0.12% chlorhexidine gluconate twice daily. 3. As a general rule, the pack is kept on for 1 week after surgery. 4. Before removing, make sure sutures are not embedded in the dressing and that the dress ing is not locked interproximally. misc. Microorganisms that colonize the periodontal abscess have been reported to be primarily:

~~• gram-positive aerobic cocci~~

~~• gram-negative aerobic rods~~

~~• gram-negative anaerobic rods~~

~~• gram-positive anaerobic cocci~~

~~misc.~~

~~Gingival fibers consist of:~~

~~• type 1 collagen~~

~~• type II collagen~~

~~• type III collagen~~

~~• type IV collagen~~

~~ft 87 copyright ® 2013-2014 - Dental Decks PERIODONTICS • gram-negative anaerobic rods~~

Principal differences between the periodontal abscess and the gingival abscess are location and history. Ab scesses confined to the marginal gingiva, caused by injury (forcing of foreign material) to the outer surface of the gin giva, and not involving the supporting structures are called gingival abscesses. A periodontal abscess is an infection located contiguous to the periodontal pocket and may result in the destruction of the PDL and alveolar bone. Note: The pericoronal abscess is associated with the crown of a partially erupted tooth.

Periodontal abscesses can be classified as: /^Acutg) The most prevalent symptom that the patient will report with an acute periodontal abscess is one of acute pain. The nature of the pain is a constant, severe, dull throbbing. Thermal changes do not seem to elicit or mod ify the discomfort. The onset of this discomfort is rapid and becomes progressively more intense. Exudate may be expressed with gentle pressure. The patient may also notice an increase in mobility of an individual tooth. The patient probably will say that it is difficult to close his/her teeth together without striking the involved tooth first (it feels elevated in the socket), causing increased pain. There may be systemic involvement characterized by an elevated temperature and lymphadenopafhy. .* Chronic:, is usually characterized by no or a dull pain, slight tooth elevation, intermittent exudation, a fistulous tract often associated with a deep pocket, and without systemic involvement.

Treatment for an acute periodontal abscess is determined initially by whether there is localization of the abscess. If there is, then the treatment is to provide drainage (either through the periodontal pocket or through external incis ion), instruct the patient to rinse with warm salt water and place chlorhexidine gluconate on the affected area with a cotton-tipped applicator. If there is systemic involvement, the patient should be prescribed antibiotics (either amoxi cillin or if allergic then clindamycin or azithromycin). If there is severe swelling and inflammation (not localized), the patient should be put on antibiotics and seen once the infection has localized. Note: Bacteria associated with ab scesses of the periodontium include F. nucleatum, P. intermedia, P. gingivalis, P. micros, and T forsythia. iwmwiimiinmM iiugti. »ii«im , I, n , u,- ^ i IIMHM •- Mrammmit As with a periodontal pocket, the chronic abscess is usually treated with scaling and root planing or surgical therapy. The radiographic findings associated with this abscess are not specific. There may be no change radiographically in the early acute lesion. However, often in a chronic abscess, there will be a localized discrete radiolucency lateral to the root or in a furcation. Note: It can cause rapid alveolar bone destruction.

Note: Microscopically, an abscess is a localized accumulation of PMNs within the periodontal pocket wall. The PMNs liberate enzymes that digest the cells and other tissue structures, forming the liquid product known as pus (ex udate).

~~• type I collagen~~

1. The connective tissue of the marginal gingiva is densely collagenous, con- Notes taining a prominent system of collagen fiber bundles called the gingival fibers. 2. The gingival fbers are arranged in three groups: gingivodental, circular, and transseptal. 3. The type I collagen of gingiva, however, is not the same biochemically as found in other parts of the body, including the skin. 4. The collagen turnover in normal gingiva is not as rapid as in the periodon tal ligament but significantly greater than in other tissues, such as the skin, ten dons, and the palate. 5. The major components of the gingival connective tissue are collagen fibers (about 60% by volume), fibroblasts (5%), vessels, nerves, and matrix (about 35%). 6. The three types of connective tissue fibers arexollagen,^reticular, anaplas tic. 7. Collagen type I forms the bulk of the lamina propria and provides the tensile strength to the gingival tissues.,, 8. Type IY... collagen (argyrpphilic reticulum fiber) branches between the colla gen type I bundles and is continuous with fibers of the basement membrane and blood vessel walls. 9. The elastic fiber system is composed of^ytalan, ejaunin, and elastin fibers distributed among collagen fibers.

Remember: YiJgjnjnC is needed for hydroxylation oforoline and lysine essential for collagen formation. misc. All of the following are contraindications to selective grinding in the natural dentition EXCEPT one. Which one is the EXCEPTION!

~~> when pulp chambers are small~~

~~• in the presence of tooth sensitivity~~

~~• when major occlusal discrepancies may require orthodontics or full mouth reconstruction~~

~~> in patients who are poor candidates for full mouth reconstruction because of psychologic factors~~

~~misc.~~

~~All of the following are clinical signs of bruxism EXCEPT one. Whichon e is the EXCEPTION!~~

~~• TMJ symptoms~~

~~• muscle soreness~~

~~• periodontal pocket formation~~

~~• cracked teeth or fillings~~

~~• wear facets on teeth~~

~~• widened PDL spaces on radiographs~~

General objectives in selective grinding in the natural dentition: • To achieve a more favorable direction and distribution of forces • To coordinate the median occlusal position with the terminal hinge position of the mandible • To eliminate prematurities in excursive movements to either gain a group function or canine-protected occlusion • To direct occlusal forces centrally along the long axis of the tooth • To improve or maintain masticatory performance • To accomplish the occlusal adjustment without reducing vertical dimension and by retaining an acceptable interocclusal distance • To reduce or eliminate fremitus The usual steps of occlusal adjustment: • Eliminate prematurities in centric relation • Eliminate prematurities in protrusive movements • Eliminate prematurities in lateral excursive movements • Reestablishment of physiologic occlusal anatomy and careful polishing of all ground surfaces

Note: For the periodontal patient, occlusal adjustment (coronoplasty) should not be done until inflammation is resolved,^^*

~~• periodontal pocket formation — periodontal pockets are inflammatory lesions that are not caused by occlusal trauma or bruxism~~

Bruxism is defined as diurnal or nocturnal parafiinctional activity that includes clenching, bracing, gnashing, and grinding of the teeth. Although no causative association exists between bruxism and gingival inflammation or periodontitis, bruxism can cause tooth mobility, tooth wear and fracture, and periodontal and muscle pain, and it may contribute to masticatory sys tem disorders. Important: A maxillary or a mandibular interocclusal appliance (occlusal splint/night guard) is generally considered the most effective means of managing bruxism. They are used to re distribute occlusal forces and to minimize excessive force on individual teeth. • To stabilize the dentition • To modify the nature of the habit (bruxism) • To act as a splint after periodontal surgery <* Jo assist in controlling recurrence of drug-induced gingival enlargement Note: Night guards are usually worn at night, but they may also be worn during the day. *** The primary purpose of a night guard in periodontal trauma is to modify and con trol bruxism or to redirect forces into a nontraumatic pattern. ight guards should have the following characteristics: • They should be made of hard acrylic 1• There should be no sharp edges — needs to be comfortable • They should fit well and cover the occlusal surfaces of the maxillary teeth - should not cover the palate • They should occlude evenly with mandibular teeth and permit the patient to move the mandible freely in all excursions misc. Which of the following statements regarding the assessment of tooth mobility is false?

~~• teeth normally have a very slight physiologic mobility~~

~~• mobility can result from multiple causes~~

~~• mobility is unacceptable and should be treated~~

~~• periodontal disease can result in tooth mobility~~

~~misc.~~

~~Which of the following is not correctly matched with regards to a periodontal treatment plan?~~

~~preliminary phase: plaque control~~

~~• phase I: mouth preparation~~

~~• phase II: periodontal surgery~~

~~• phase III: restorative~~

~~• phase IV: maintenance~~

Mobility should be treated if it is progressive (increasing), acting to contribute to pro gression of periodontal disease, or if it is associated with patient pain. Mobility in the ab sence of inflammation is not harmful. Not all mobility can be eliminated. Also, some mobility is only transient. Mobility beyond the physiologic range is termed abnormal or pathologic. It is pathologic in that it exceeds the limits of normal mobility values; the periodontium may not neces sarily be diseased at the time of examination.

Increased tooth mobility may be caused by a variety of factors, including pregnancy, dis eases (local and systemic), trauma (including orthodontic movement), and hypofunction or hyperfunction. The two factors most often seen would be^^ue-induced inflammatory disease and excessive occlusal forces (bruxism). Note: As a general rule, mobility is graded clinically with a simple method. The tooth is held firmly between the handles of two metallic instruments or with one metallic instru ment and one finger, and an effort is made to move it in all directions; abnormal mobil ity most often occurs faciolingually. Mobility is graded according to the ease and extent of tooth movement, as follows: • Normal mobility • Grade I: slightly more than normal • Grade II: moderately more than normal • Grade III: severe mobility faciolingually and mesiodistally, combined with vertical displacement.

• preliminary phase: plaque control *** Plaque control is a part of Phase I or initial therapy. The preliminary phase includes treatment of emergencies only, whether they be pulpal, periodontal, or any other. {Phase I (initial therapy), of periodontal treatment planning includes: • Caries control, extraction of hopeless teeth • Mouth preparation - Initial scaling (full mouth) - Definitive root planing • Oral hygiene instructions: This is the most important aspect of initial therapy. The dental hygienist or dentist teaches, motivates, and guides the patient in the performance of measures for disease control. During a prophy appointment, the hygienist or dentist can establish a rapport with the patient and individualize instruction for the particular patient, show the proper brush ing and flossing techniques, and have them repeat these techniques to see if they understand what you are showing them. • Occlusal adjustment • Night guards (if bruxism exists) • Splinting (stabilizing loose teeth) • Re-examination (charting with probings)

~~Remember| ^?J^ hygiene is poor, surgery is contraindicated!!!~~

~~PhasX e II (periodontal surgery) • Phase I • Reevaluatlon >- Phase IV (maintenance)~~

~~Phase III (restorative)~~

~~Correct sequence of periodontal treatment misc. Cellular cementum (contrasted with acellular cementum) is:~~

~~• cementum that is resorbing~~

~~1 newly formed cementum~~

~~• that part of the cementum that is adjacent to the enamel~~

~~• cementum that contains cementocytes~~

~~misc. All of the following statements concerning B cells are true EXCEPT one Which one is the EXCEPTION!~~

~~• they mature in the bone marrow and migrate to lymphoid organs~~

~~• they are found in the germinal centers of the spleen and lymph nodes~~

~~• they are progenitors of plasma cells~~

~~• they are involved in humoral (antibody-mediated) and cell-mediated immunity~~

93 copyright © 2013-2014 - Dental Decks PERIODONTICS • cementum that contains cementocytes Cementum is the calcified, avascular mesenchymal tissue that forms the outer covering of the anatomic root. The two main types of cementum are acellular (primary) and cellular (sec ondary) cementum. Both consist of a calcified interfibrillar matrix and collagen fibers. The two main sources of collagen fibers in cementum are (^"Sharpey fibers (extrinsic), which are the embedded portion of the principal fibers of the periodontal ligament and are formed by the fibroblasts, and (2) fibers that belong to the cementum matrix (intrinsic) and are pro duced by the cementoblasts. The major proportion of the organic matrix of cementum is composed of type l.(9Q%) and type III (about 5%) collagens. Sharpey fibers, which constitute a considerable proportion of the bulk of cementum, are composed of mainly collagen type I. Type III collagen appears to coat the type I collagen of Sharpey fibers. • Acellular cementum: is the first cementum formed, covers approximately the cervical c third or half of the root, and does not contain cells. Sharpey fibers make up most of the structure of acellular cementum, which has a principal role in supporting the tooth. • Cellular cementum: is formed after the tooth reaches the occlusal plane, is more irregu- "** lar, and contains cells (cementocytes). It is less calcified than acellular cementum. Sharpey fibers occupy a smaller portion of cellular cementum. If vital cementum is resorbed or nicked in surgical procedures, the defect is repaired by the deposition of new cementum. Repair cannot occur where pockets are present or where the gingiva has receded and the cementum is exposed. Cementum that has become exposed, form ing part of the clinical crown, is often removed in the course of scaling, root planing, or brush ing. Note: Cementum deposition is a continuous process that proceeds at varying rates throughout life. Gementam formation-is most rapid in the apical regions, where it compensates for tooth eruption, which itself compensates for attrition.

~~• they are involved in humoral (antibody-mediated) and cell-mediated immunity~~

*** This is false; B cells are not involved with cell-mediated immunity. Lymphocytes: the three main types of lymphocytes are distinguished on the basis of their receptors for antigens: T lymphocytes, B lymphocytes, and natural killer (NK) cells. • T cells: recognize diverse antigens using a low-affinity transmembranous complex, the T cell antigen receptor (TCR). T cells are subdivided based on whether they pos sess the coreceptors CD4 or CD8. Note: They are important in cell-mediated immu nity, Type 4 hypersensitivity reactions (contact dermatitis), and in the modulation of _antibody-mediated immunity. : • B cells: help control extracellular antigens, such as bacteria, fungal, yeast, and viri ons. B cells recognize diverse antigens using the B cell antigen receptor (BCR). After antigen exposure, some B cells differentiate to form plasma cells, which secrete. IgM. Others differentiate into memory B cells. Note: They are important in antibody-me diated immunity. (• Natural killer (NK) cells: recognize and kill certain tumor and virally infected cells.

Note: Patients with periodontitis often have T lymphocytes sensitized to plaque bacter ial antigens. misc. When trauma from occlusion results from reduced ability of the tissues to resist the occlusal forces, it is known as:

~~• primary occlusal trauma~~

~~• secondary occlusal trauma~~

~~• tertiary occlusal trauma~~

~~misc.~~

~~Which of the following is true of cementum? Select all that apply.~~

~~• the main function is to compensate for tooth wear~~

~~• it is produced by cells of the periodontal ligament~~

~~• the deposition of new cementum continues periodically throughout life whereby root fractures may be repaired~~

~~• the cementum is indistinguishable on radiographs~~

~~• it is lighter in color than dentin, contains 45% to 50% inorganic substance, and its permeability diminishes with age~~

When occlusal forces exceed the adaptive capacity of the tissues, tissue injury results. The result ant injury is termed trauma from occlusion. Trauma from occlusion refers to tissue injury, not oc clusal force. An occlusion that produces such injury is called a traumatic occlusion. Trauma from occlusion may be: • Acute: results from an abrupt occlusal impact, such as that produced by biting on a hard ob ject. Restorations or appliances that interfere with or alter the direction of occlusal forces on the teeth may also induce acute trauma. It results in tooth pain, sensitivity to percussion, and in creased tooth mobility. • Chronic: is more common than the acute form and is of greater clinical significance. It most often develops from gradual changes in occlusion produced by tooth wear, drifting movement, and extrusion of teeth, combined with parafunctional habits such as bruxism and clenching, rather than as a sequela of acute periodontal trauma.

When trauma from occlusion is the result of alterations in occlusal forces, it is called "primary trauma from occlusion." It occurs if trauma from occlusion is considered the primary etiologic factor in periodontal destruction and if the only local alteration to which the tooth is subjected is from occlusion. Important: Changes produced by primary trauma do not alter the level of con nective tissue attachment and do not initiate pocket formation. This is probably because the supracrestal gingival fibers are not affected and, therefore, prevent apical migration of the junc tional epithelium.

Secondary trauma from occlusion occurs when the adaptive capacity of the tissues to withstand occlusal forces is impaired by bone loss resulting from marginal inflammation. This reduces the pe riodontal attachment area and alters the leverage on the remaining tissues. The periodontium be comes more vulnerable to injury, and previously well-tolerated occlusal forces become traumatic. Tissue response to traumatic occlusion occurs in three stages; injury, repair, and adaptive remod eling of the periodontium.

• it is produced by cells of the periodontal ligament • the deposition of new cementum continues periodically throughout life whereby root fractures may be repaired • the cementum is indistinguishable on radiographs • it is lighter in color than dentin, contains 45% to 50% inorganic substance, and its permeability diminishes with age

~~Important: the main function is the attachment of principal fibers of the PDL.~~

Other functions include: 1. Compensates Jrrrjheloss of tooth surface due to occlusal wear by apical deposition of cementum throughout life. /\JProJ;ects the root surface from resorption during vertical eruption and tooth movement. 3. Has a reparative function; allows reattachment of connective tissue following perio dontal treatment. Note: Cementum repair requires the presence of viable connective tissue. If epithelium proliferatesinto an areTofresorption, repair will not take place. Cementum . repair can occur in devitalized as well as vital teeth. The inorganic content of cementum (hydroxyapatite) is 45% to 50%, which is less than that of bone (65%), enamel (97%), or dentin (70%). The cementum at and immediately subjacent to the cementoenamel junction (CEJ) is of par ticular clinical importance in root-scaling procedures. Three types of relationships involving the cementum may exist at the CEJ. In about 60% to 65% of cases, cementum overlaps the enamel; in about 30%, an edge-to-edge butt joint exists; and in 5% to 10%, the cementum and enamel fail to meet.

Note: Unlike bone, which is continuously remodeled, the cementum grows slowly in thickness throughout life, by apposition of new cementum at the surface. While cementum can be resorbed, it is not continuously remodelled like bone. misc. The most common indication to splint mobile teeth is to:

~~• improve patient comfort and to provide better control of the occlusion if the anterior teeth are mobile~~

~~• improve oral hygiene~~

~~• prevent a natural unopposed tooth from migrating~~

~~> prevent maxillary central incisors from separating after closure of diastema~~

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~~misc. In combined endodontic-periodontic lesions, it is generally wise to treat:~~

~~• the periodontic component first~~

~~• the endodontic component first~~

~~• both components at the same time~~

~~• them any way you want to~~

Splinting therapy may be applied with bonded external appliances, intracoronal appliances, or in direct cast restorations to connect multiple teeth, with the goal of improving tooth stability. Unsta ble teeth may be caused by a lack of periodontal support from bone loss, a lack of support from tooth loss, or the need to splint abutment teeth to support pontics.

There is no reason for splinting nonmobile teeth as a preventive measure. Splinting is only one measure used in the treatment of periodontal disease. Splinting should be used with other neces sary measures, such as root planing, oral hygiene instructions, pocket elimination, and occlusal ad justment. Loose teeth splinted to adjacent teeth may become stabilized. When many teeth are loose, adjacent sextants should be included in the splint. Teeth tend to loosen buccolinguallv yet may remain firm mesiodistally. Even when teeth do not tighten, the splint serves as an orthopedic brace that permits useful function of loose teeth. A variety of means may be utilized to achieve tempo rary stabilization. Whatever means are used, special attention should be paid to making the splint amenable to oral hygiene procedures and instructing the patient on plaque control around the splint.

1. Indications for splinting are (1) mobility of teeth that is increasing or that impairs pa- Notes tient comfort, (2) migration of teeth, or (3) prosthetics where multiple abutments are necessary. 2. Before considering splinting, the clinician must identify the etiology of the instabil ity. Any inflammation of the periodontal supporting apparatus must be controlled before making a decision on splinting because inflammation can produce mobility in the pres ence of normal occlusal forces and normal periodontal support. 3. Adequate crown length on the teeth being splinted is critical so that the interproximal connectors do not impinge on the interdental papilla. 4. Adequate space must exist between the connector and the papilla for access with den tal floss anteriorly and with an interproximal brush on posterior teeth.

~~• the endodontic component first~~

In patients with a dental abscess, the differential diagnosis between periodontal and en dodontic origin can usually be established by the history, clinical examination, and radi ographs. The true combined lesion results from the development and extension of an endodontic lesion into an existing periodontal lesion (pocket)/Ttie pain from the loss of pulpal vitality is the most common presenting complaint of patients with combined le sions. The "symptoms reported are those most often found with pulpal disease. Thermal pulptesting provides information relative to the status of the pulp, and dental radiographs can confirm the presence of apical changes and the extent of bone loss. Careful probing confirms the presence and morphology of any periodontal pocket and permits location of the communication with the apical lesion.

In combined endodontic-periodontic lesions, it is generally wise to treat the endodon tic component first, because in many cases, this will lead to complete resolution of the problem. After successful endodontic treatment, the residual periodontal pocket that remains can be more predictably treated. The periodontal therapeutic objectives vary with the extent and configuration of the residual periodontal lesion. Important: The long-term prognosis for a tooth with a combined lesion is closely related to the extent and configuration of the periodontal attachment loss. With advanced hori zontal bone loss, even an optimal endodontic result may not be sufficient to retain the tooth. If the periodontal lesion is an advanced, multiwalled vertical defect, the success of therapy likely depends on the ability to fill or regenerate attachment to obliterate the de fect. misc. Trauma from occlusion can produce radiographically detectable changes in all of the following EXCEPT one. Which one is the EXCEPTION!

~~• lamina dura~~

~~' periodontal pockets~~

~~• width of the PDL space~~

~~• morphology of the alveolar crest~~

~~> density of the surrounding cancellous bone~~

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~~misc. Extrinsic dental stains include:~~

~~green to brown stains caused by erythroblastosis fetalis~~

~~brown, black, green, or orange stains caused by chromogenic bacteria in plaque~~

~~red to brown stains caused by congenital porphyria~~

~~• gray or brownish stains caused by tetracycline~~

99 copyright O 2013-2014 - Dental Decks PERIODONTICS jeriodontal pockets *** Periodontal pockets are not caused by occlusal trauma. A local irritant and inflam mation are necessary to cause apical shift of the epithelial attachment. The most common clinical sign of occlusal trauma is'tooth mobility. Other clinical signs of occlusal trauma include^migration of teeth and the Itenderness of teeth to percussion. Traumatic lesions manifest more clearly in the faciolingual aspects because, mesiodis tally, the tooth has the added stability provided by the contact areas with adjacent teeth. Radiographic signs of trauma from occlusion: • Widening of the periodontal ligament space • Thickening of the lamina dura • Angular bone loss and infrabony pocket formation • Root resorption • Hypercementosis Note: Trauma from occlusion is reversible, that is, the body can repair the damage if the excessive occlusal forces are eliminated. Other findings associated with excessive occlusal forces: • Alternating areas of resorption and repair of the alveolar bone • Fibrosis of the alveolar bone marrow spaces • Cemental resorption leading to dentinal resorption • Cemental tears • Possible ankylosis • Occasional pulpal necrosis and calcification Radiographic changes that may be seen on teeth that are no longer in function: • Reduced trabeculation of bone • Narrowing of the periodontal ligament space

~~• brown, black, green, or orange stains caused by chromogenic bacteria in plaque~~

Stains can be identified by location: • Intrinsic - stains that occur within the tooth substance • Extrinsic - stains that occur on the external surface of the tooth Stains can be identified by sources of the discoloration: • Endogenous - stain that originates from within the tooth. Endogenous stains are al ways intrinsic and frequently are discolorations of the dentin reflected through the enamel. Examples of sources: drugs (tetracycline, systemic fluoride), changes in pulp tissue of pulpless teeth, imperfect tooth development (amelogenesis imperfecta) • Exogenous - stain that originates from an external source. Brown, black, green, and orange stains are generally seen on the labial surface of an terior teeth and are usually caused by poor oral hygiene. Some theories attribute the change in color to by-products of some bacteria. Black stain is generally seen in the cer vical portion of molar teeth in children. Green and orange stains are supposedly asso ciated with an increased amount of caries and, actually, they represent pigmentation of dental plaque. Black line, tobacco, orange and green stains are all exogenous extrin sic stains, initially at least. With time, both green and tobacco stains may become in corporated within the tooth. At this po]nt, their classification changes. They become exogmojos Intrinsic stains. -vStfyer amalgarn andSeopical fluoride are also examples of exogenous intrinsic stains. An exogenous intrinsic stain is one that originates from a source outside the tooth and sub sequently becomes incorporated within the tooth structure. oh

~~Abrasives:~~

~~• compose 5% to 10% of dentifrices~~

~~• compose 10% to 20% of dentrifrices~~

~~• compose 20% to 40% of dentrifices~~

~~• compose 50% to 65% of dentrifices~~

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~~misc.~~

~~Water irrigation devices (oralirrigators) have beeni shown to:~~

~~• eliminate plaque~~

~~• clean nonadherent bacteria and debris from the oral cavity more effectively than toothbrushes and mouth rinses~~

~~• disinfect pockets for up to 12 hours~~

~~• prevent calculus formation~~

Dentifrices aid in cleaning and polishing tooth surfaces. They are used mostly in the form of pastes, although tooth powders and gels are also available. Dentifrices are made up of abrasives (e.g., silicon oxides, aluminum oxides, granular polyvinyl chlorides), water, humectants, soap or detergent, flavoring and sweetening agents, therapeutic agents (e.g., fluorides, pyrophosphates), coloring agents, and preservatives. Abrasives (compose 20%, to 40% of dentifrices) are insoluble inorganic salts that enhance the abrasive action of toothbrushing as much as 40 times. Tooth powders are much more abrasive than pastes and contain about 95% abrasive materials. The abrasive quality of dentifrices affects enamel only slightly and is a much greater concern for patients with ex posed roots. Dentin is abraded 25 times faster and cementum 35 times faster than enamel, so root surfaces are easily worn away, leading to notching and root sensitivity. Note: Typically, more wear occurs on maxilary than mandibular teeth and on the left half than on the right half of the dental arch. Important: In dentifrices, fluoride ion must be available in the amount of iQflfltaJHK) parts per million (ppm) to achieve caries reduction effects. "Calculus control toothpastes," also referred to as "tartar control toothpastes," contain pyrophosphates and have been shown to reduce the deposition of new calculus on teeth. These ingredients interfere with crystal formation in calculus but do not affect the fluo ride ion in the paste. Dentifrice with pyrophosphates has been shown to reduce the for mation of new supragingival calculus by 30% or more. Pyrophosphate-containing toothpastes donoj affect subgingival calculus formation or gingival inflammation. The inhibitory effect reduces the deposition of new supragingival calculus but will not affect existing calculus deposits.

• clean nonadherent bacteria and debris from the oral cavity more effectively than toothbrushes and mouth rinses Oral irrigators for daily home use by patients work by directing a high-pressure, steady or pulsating stream of water through a nozzle to the tooth surfaces. Most often, a device with a built-in pump generates the pressure. Oral irrigators clean nonadherent bacteria and debris from the oral cavity more effectively than toothbrushes and mouth rinses. When used as adjuncts to toothbrushing, these devices can have a beneficial effect on periodontal health by reducing the accumulation of plaque and calculus and decreasing inflammation and pocket depth.

Oral irrigation has been shown to disrupt and detoxify subgingival plaque and can be use ful in delivering antimicrobial agents into periodontal pockets. Note: Daily supragingival irrigation with a dilute antiseptic, chlorhexidine, for 6 months resulted in significant re ductions in bleeding and gingivitis compared with water irrigation and chlorhexidine rinse controls. Irrigation with water alone also reduced gingivitis significantly, but not as much as the dilute chlorhexidine.

Important: Oral irrigators may be contraindicated in patients requiring antibiotic pre medication prior to dental treatment since these devices have the potential for causing a bacteremia. The patient's physician should be consulted.

~~Remember: The pathology associated with gingivitis is completely reversible with the removal of plaque and the resolution of the inflammation. oh~~

~~The effectiveness of toothbrushing is best measured by:~~

~~• the amount and location of plaque~~

~~• the caries experience~~

~~• the toothbrushing frequency~~

~~• the condition of the toothbrush~~

~~Which component of Super Floss" is most effective in cleaning around appli ances and between wide spaces?~~

~~• stiffened end~~

~~•spongy floss~~

~~• regular floss~~

103 copyright e 2013-2014 - Dental Decks PERIODONTICS • the amount and location of plaque Over the years, many different toothbrushing methods have been described and promoted as being efficient and effective. These methods can be categorized primarily according to the pattern of motion when brushing and are primarily of historical interest, as follows: • Roll: Roll method or modified Stillman technique • Vibratory: Stillman, Charters, and Bass techniques • Circular: Fones technique • Vertical: Leonard technique • Horizontal: Scrub technique Studies evaluating the effectiveness of the most common techniques have demonstrated no clear superiority for any method. The scrub technique is probably the simplest and most common method of brushing. Patients with periodontal disease are most frequently taught a sulcular brushing technique using a vibratory motion to improve access in the gingival areas. The method most often recommended is the Bass technique because it emphasizes sulcular placement of bristles. Bass method: • Place toothbrush so that the bristles are angled approximately 45 degrees from the tooth surfaces. This allows the bristles to extend into the gingival sulcus when pressure is ap plied to the brush in a horizontal direction. • Start at the most distal tooth in the arch, and use a vibratory, back-and-forth motion to brash Other methods of brushing, such as the modified Stillman and Charters, are variations of the Bass technique also designed to achieve thorough plaque removal at the gingival margins. They emphasize stimulation of the gingival circulation, which has not been demonstrated to achieve healing results beyond those achieved by good plaque removal. Important: No matter what toothbrushing method is chosen, the manual toothbrush should have soft nylon bristles and a small head. They should be replaced about every 3 months. . °.,-"'"

~~• spongy floss~~

Super Floss® is ideal for cleaning braces, bridges, and wide gaps between teeth. Its three unique components - a stiffened end, spongy floss, and regular floss - all work together for maximum benefits.

Three components: • Stiff-end threader so you can floss under appliances • Spongy floss cleans around appliances and between wide spaces • Regular floss removes interproximal subgingival plaque Indications for use of Super Floss® include plaque removal around the following: - Isolated teeth - Teeth separated by a diastema - Wide embrasures where interdental papillae have been lost - Fixed partial dentures (bridgework) - Orthodontic appliances - Implants oh

~~Which of the following oral hygiene a ids is appropriate for cleaning a Class II furcation?~~

~~• stim-u-dent®~~

~~• interproximal brushes~~

~~• interdental stimulator~~

~~• perio-aid®~~

~~• oral irrigator~~

~~oh To date, the ADA has accepted two agents for treatment of gingivitis, these are:~~

~~• prescription solutions of chlorhexidine digluconate oral rinse~~

~~• prescription solutions of tetracycline oral rinse~~

~~• nonprescription essential oil oral rinse~~

~~• nonprescription solutions of penicillin oral rinse~~

A tapered, round toothpick is inserted into the hole in the carrier and is then broken off. The tip is left in and is used in a tracing motion along the gingival margins. It is also help ful in cleaning furcations that are accessible. • Stim-U-Dent® (balsa wood wedges): these are of primary importance in gingiva] igassage. They are also good for patients with interdental recession. These picks (tri angular in cross section) are small enough to fit into most interdental spaces. As a sup plement to brushing, they are useful for dislodging interproximal debris often missed by meticulous brushing and for massaging the underlying interproximal gingiva. • Interproximal brushes (Proxabrush): are used for interdental cleansing when the interdental space is wide. The brushes are replaceable. • Interdental stimulator: consists of a rubber tip of smooth or ribbed conical shape at tached to a handle or to the end of a toothbrush. Its action massages and stimulates cir culation of the interdental gingiva and may increase the tone of the tissue. It is not recommended for areas in which the papillae are normal and fill the interproximal spaces. It may cause injury to the gingival tissue.

Remember: 1. Nothing replaces brushing and flossing for removal of or disruption of plaque. 2. Frequent brushing and flossing helps to prevent calculus formation by breaking up the matrix of plaque. 3. New plaque growth occurs shortly after brushing and flossing (starts interproxi mal and works its way around the tooth).

• prescription solutions of chlorhexidine digluconate oral rinse • nonprescription essential oil oral rinse The agent that has shown the most positive antibacterial results to date is chlorhexidine, a diguanidohexane with pronounced antispetic properties. The 0.12% chlorhexidine digluconate preparation available in the United States for reducing plaque and gingivitis has been shown to be equally effective as the higher-concentration product (0.2%, aqueous solution). Localized, reversible side effects of chlorhexidine use may occur; primarily brown staining of the teeth, tongue, and silicate and resin restorations and transient impairment of taste perception. Chlorhexidine has very low sytemic toxic activity in humans, has not produced any appreciable re sistance of oral microorganisms, and has not been associated with teratogenic alterations. Note: 0.12% chlorhexidine contains 12% alcohol Chorhexidine's effectiveness may be explained by the fact that it leaves the greatest residual concentration in the mouth after its use. It is approved by the ADA as an antimicrobial and antigin- givitis agent. Examples include: Peridex and Periogard. Important: Substantivity is the ability of drugs to adsorb onto and bind to soft and hard tis sues. The substantivity of chlorhexidine was first described in the 1970s. Due to this property, chlorhexidine can maintain effective concentration for prolonged periods of time. Essential oil mouth rinses contain thymol, eucalyptol, methanol, and methyl salicylate. These products also contain alcohol (up to 24% depending on the preparation). An example is I^isterine. A product containing triclosan has shown some effectiveness in reducing plaque and gingivitis. It is available in toothpaste form, and the active ingredient is more effective in combination with zinc citrate or a copolymer of methoxyethylene. Other oral rinse products on the market have shown some evidence of plaque reduction, although long-term improvement in gingival health has not been substantiated. These include stgjjnous flu oride, cejylpyridinium chloride (quaternary ammonia compounds), and s^aguinarine. pdl/g ie attachment apparatus is composed of all of the following EXCEPT one. Which one is the EXCEPTION!

~~• periodontal ligament~~

~~• cementum~~

~~• alveolar bone~~

~~• gingiva~~

~~Which of the following is the only local delivery system of antibiotics acccepted by the ADA and is available in the United States and a number of other countries?~~

~~• 10%doxycyclinegel -* fo&\c&a&~~

~~• 2% minocycline microspheres —£ fi^^es-tj ^»~~

~~• 25% metronidazole gel~~

~~• chlorhexidine (2.5mg) in gelatin matrix —^ f U\i©CkvLf .~~

The periodontium conists of the investing and supporting tissues of the tooth: gingiva, periodontal ligament, cementum, and alveolar bone. It has been divided into two parts: 1. Gingiva: the main function of which is protecting the underlying tissues 2. Attachment apparatus: composed of the: • Periodontal ligament • Cementum • Alveolar bone The cementum is considered a part of the periodontium because, with the bone, it serves as the support for the fibers of the periodontal ligament.

The gingival fluid (sulcular fluid) contains components of connective tissue, epithelium, inflammatory cells, serum, and microbial flora inhabiting the gingival margin or the sul cus (pocket). In the healthy sulcus, the amount of gingival fluid is very small. During in flammation, however, the gingival fluid flow increases, and its composition starts to resemble that of an inflammatory exudate.

~~The main route of the' gingival fluid diffusion is through the basement membrane, through the relatively wide intracellular spaces of the junctional epithelium, and then into the sul cus.~~

The gingival fluid is believed to: • Cleanse material from the sulcus • Contain plasm'a proteins that may improve adhesion of the epithelium to the tooth • Possess antimicrobial properties • Exert antibody activity to defend the gingiva

~~nt*1 \ct&0 /T^ 10% doxycycline gel~~

The limitations of mouth rinsing and irrigation have prompted research for the development of alternative de livery systems. Recently, advances in delivery technology have resulted in the controlled release of drugs. • Subgingival Doxycycline: the FDA approved 10% doxycycline in a gel system using a syringe (ATRIC- DOX. It is the only local delivery system accepted by the ADA. • Subgingival Minocycline: the FDA recently approved a new, locally delivered, sustained-release form of minocycline microspheres (ARESTIN) for subgingival placement as an adjunct to scaling and root planing. The 2% minocycline is encapsulated into bioresorbable microspheres in a gel carrier. • Subgingival Metronidazole: a topical medication containing an oil-based metronidazole 25% dental gel (glycerol monooleate and sesame oil) has been tested in a number of studies. This product is hot available in the U.S. • Chlorhexidine in a gelatin matrix: a resorbable delivery system has been tested for the subgingival placement of chlorhexidine gluconate with positive clinical results. PerioChip is a small chip (4.0 x 5.0 x 0.35 mm) composed of a biodegradable hydrolyzed gelatin matrix, cross-linked with glutaraldehyde and also containing glycerin and water, into which 2.5 mg of chlorhexidine gluconate has been incorporated per chip.

Systemic administration of antibiotics: • Tetracyclines: used to treat LAP (locally aggressive periodontitis): have the ability to concentrate in the periodontal tissues and inhibit the growth of Actinobacillus actinomycetemcomitans (Aa). Note: Suban- timicrobial-dose doxycycline (SDD) is a 20-mg dose of doxycycline (Periostat) that is approved and indi cated as an adjunct to scaling and root planing in the treatment of chronic periodontitis. It is taken twice daily for 3 months, up to a maximum of 9 months continuous dosing. • Metronidazole: is effective againstAa when used in combination with other agents. It is effective against anearobes such as Pprphyromonas gingivalis and Pyevotella intermedia. • Penicillins (amoxicillin and amoxicillin-clavulanatepotassium [Augmentin]): may be useful in the man- agment of aggressive periodontitis (both localized and generalized forms). • Cephalosporins: not often used to treat dental-related infections. • Clindamycin: used when patients are allergic to penicillin. .' • Ciprofloxacin: is the only antibiotic in periodontal therapy to which all strains of Aa are susceptible. • Macrolides (erythromycin, spiramycin, and azithromycin): only azithromycin is used and appears to con centrate in gingival tissues. pdl/g The gingival fibers are arranged in three groups. Which of the following is not one of those groups?

~~• circular group~~

~~•gingivodental group~~

~~•apical group~~

~~• transseptal group~~

~~pdl/g~~

~~Of the choices listed below, which one describes the boundaries that define the attached gingiva?~~

~~> from the gingival margin to the interdental groove~~

~~• from the free gingival groove to the gingival margin~~

~~> from the mucogingival junction to the free gingival groove~~

~~> from the epithelial attachment to the cementoenamel junction~~

The connective tissue of the marginal gingiva is densely collagenous, containing a prominent sys tem of collagen fiber bundles called the gingival fibers. They consist of type I collagen. The gin gival fibers have the following functions: 1. To brace the marginal gingiva firmly against the tooth. 2. To provide the rigidity necessary to withstand the forces of mastication without being de flected away from the tooth surface. 3. To unite the free marginal gingiva with the cementum of the root and the adjacent attached gin giva- The gingival fibers are arranged in three groups: • Gingivodental group: these fibers are those on the facial, lingual, and interproximal surfaces. They are embedded in the cementum just beneath the epithelium at the base of the gingival sul cus. • Circular group: these fibers course through the connective tissue of the marginal and inter dental gingivae and encircle the tooth in ringlike fashion. They resist rotational forces. • Transseptal group: these fibers are located interproximally and form horizontal bundles that extend between the cementum of approximating teeth into which they are embedded. They lie in the area between the epithelium at the base of the gingival sulcus and the crest of the inter dental bone. They are sometimes classified with the principal fibers of the PDL.

1. The attachment apparatus is a term used to describe these gingival fibers and the Notes epithelial attachment. 2. Some studies have also described two more gingival fiber groups: (1) a group of semicircular fibers and (2) a group of transgingival fibers 3. Tractional forces in the extracellular matrix produced by fibroblasts are believed to be the forces responsible for generating tension in the collagen. This keeps the teeth tightly bound to each other and to the alveolar bone.

~~• from the mucogingival junction to the free gingival groove (base of the sulcus)~~

In an adult, normal gingiva covers the alveolar bone and tooth root to a level just coronal to the CEI. The gingiva is divided anatomically into marginal, attached, and interdental areas. • Marginal or unattached gingiva: is the terminal edge or border of the gingiva surrounding the teeth in collarlike fashion. In about 50% of cases, it is demarcated from the adjacent attached gin giva by a shallow linear depression, the free gingival groove. Usually about 1 mm wide, the marginal gingiva forms the. soft tissue wall of the gingival sulcus. • Attached gingiva: is continuous with the marginal gingiva. It is firm, resilient, and tightly bound to the underlying periosteum of alveolar bone. The facial aspect of the attached gingiva extends to the relatively loose and movable alveolar mucosa and is demarcated by the mucogingival junction. *** The width of the attached gingiva is an important clinical parameter. It is the distance be tween the mucogingival junction and the projection on the external surface of the bottom of the gingival sulcus or the periodontal pocket. It should not be confused with the width of the kera tinized gingiva because the latter also includes the marginal gingiva. *** The width of the attached gingva on the facial aspect differs in different areas of the mouth. It is generally greatest in the incisor region and narrower in the posterior segments. *** Because the mucogingival junction remains stationary throughout adult life, changes in the width of the attached gingiva are caused by modifications in the position of its coronal portion. The width of the attached gingiva increases with age and in supraerupted teeth. • Interdental gingiva: occupies the gingival embrasure, which is the interproximal space beneath the area of tooth contact. The interdental gingiva can be pyramidal or can have a "col" shape. The shape of the gingiva in a given interdental space depends on the contact point between the two ad joining teeth and the presence or absence of some degree of recession. Note: "Stippling" of the attached gingiva refers to the irregular surface texture of the attached gingiva, similar to the surface of an orange peel. Stippling occurs at the intersection of epithelial ridges that causes the depression and the interspersing of connective tissue papillae between these intersections, giving rise to the small bumps. pdl/g

~~The principal fibers of the periodontal ligament are arranged in four groups.~~

~~The molecular configuration of collagen fibers in the periodontal ligament provides them with a tensile strength greater than that of steel.~~

~~• both statements are true~~

~~• both statements are false~~

~~• the first statement is true, the second is false~~

~~• the first statement is false, the second is true~~

~~pdl/g~~

~~Because of the high turnover rate, the connective tissue of the gingiva has a remarkably good healing and regenerative capacity.~~

~~The reparative capacity of the gingival connective tissues is not as great as that of the periodontal ligament or the epithelial tissue.~~

~~• both statements are true~~

~~• both statements are false~~

~~• the first statement is true, the second is false~~

~~• the first statement is false, the second is true~~

111 copyright © 2013-2014 - Dental Decks PERIODONTICS • the first statement is false, the second is true The most important elements of the periodontal ligament are the principal fibers, which are col lagenous and arranged in bundles and follow a wavy course when viewed in longitudinal section. The terminal portions of the principal fibers that are inserted into cementum and bone are termed Sharpey fibers. The principal fibers of the periodontal ligament are arranged in six groups that develop sequentially in the developing root: •JTranssegtal fibers: extend interproximally over the alveolar bone crest and are embedded in the cementum of adjacent teeth. These fibers keep all the teeth aligned (they maintain the integrity of the dental arches). Note: These fibers may be considered as belonging to the gingivTrJeTaTise ""mey'do not haveosseous attachment. » Alveolar crest fibers: extend obliquely from the cementum just beneath the junctional ep ithelium to the alveolar crest. These fibers prevent the extrusion of the tooth and resist lateral tooth movements. • Horizontal fibers: extend at right angles to the long axis of the tooth from the cementum to the alveolar bone. •jOblique fibers: the largest group in the periodontal ligament, they extend from the cementum in a coronal direction obliquely to the bone. They bear the brunt of vertical masticatory stresses and transform them into tension on the alveolar bone. • Apical fibers: radiate in a rather irregular manner from the cementum to the bone at the api cal region of the socket. They do not occur on incompletely formed roots. • Tjiterradicular fibers: fan out from the cementum to the tooth in the furcation areas of multi rooted teeth. Note: Small collagen fibers associated with the larger principal collagen fibers have been found. These fibers run in all directions, forming a plexus called the indifferent fiber plexus. Important: The molecular configuration of collagen fibers provides them with a tensile strength greater than that of steel. Consequently, collagen imparts a unique combination of flexibility and strength to the tissues.

~~• both statements are true~~

The dominant cellular element in the gingival connective tissue is the fibroblast. Numerous fibroblasts are found between the fiber bundles. Fibroblasts are of mesenchymal origin and play a major role in the development, maintenance, and repair of gingival connective tissue. Mast cells are numerous in the connective tissue of the oral mucosa and the gingiva. Fixed macrophages and histiocytes are present in the gingival connective tissue as components of the mononuclear phagocyte system and are derived from blood monocytes. Adipose cells and eosinophils, although scarce, also are present in the lamina propria. In clinically normal gingiva, small foci of plasma cells and lymphocytes are found in the connective tissue near the base of the sulcus. These inflammatory cells usually are present in small amounts in clinically normal gingiva.

Three sources of blood supply to the gingivaare as follows: 1. Supraperiosteal arterioles: along the"facial and lingual surfaces of the alveolar bone, from which capillaries extend along the sulcular epithelium and between the rete pegs of the external gingival surface. 2. Vessels of the PDL:which extend into the gingiva and anastomose with capillaries in the sulcus area. 3. Arterioles: which emerge from the crest of the interdental septa and extend parallel to the crest of the bone to anastomose with vessels of the PDL. The lymphatic drainage of the gingiva brings in the lymphatics of the connective tissue papil lae. It progresses into the collecting network external to the periosteum of the alveolar process, then to the regional lymph nodes, particularly the submaxillary group. Within the gingival connective tissues, most nerve fibers are myelinated and are closely as sociated with the blood vessels. Gingival innervation is derived from fibers arising from nerves in the PDL and from the labial, buccal, and palatal nerves. pdl/g

~~Cervical line contours are closely related to the attachment of the gingiva at the neck of the tooth. The greatest contour of the cervical lines and gingival attachments occur on:~~

~~• the distal surface of anterior teeth~~

~~• the distal surface of posterior teeth~~

~~• the mesial surface of anterior teeth~~

~~• the mesial surface of posterior teeth~~

~~The junctional epithelium consists of a collarlike band of stratified squamous nonkeratinizing epithelium.~~

~~The reduced enamel epithelium is not essential for its formation.~~

~~• both statements are true~~

~~• both statements are false~~

~~• the first statement is true, the second is false~~

~~• the first statement is false, the second is true~~

*** The mesial surface of the maxillary central has the greatest curvature.

All teeth generally have a greater proximal cervical line (CEJ) curvature on the mesial than the distal. Also, the proximal cervical line (CEJ) curvatures are greater on the in cisors and tend to get smaller when moving toward the last molar, where there may be no curvature at all.

~~The cementoenamel junction of all teeth curves in two directions: • Toward the apex on the facial and lingual surfaces • Away from the apex on the mesial and distal surfaces~~

~~In the absence of periodontal disease, the configuration of the crest of the interdental alveolar septa is determined by the position of the CEJ on adjacent teeth.~~

The width of the interdental alveolar bone is determined by the tooth form present. Rel atively flat proximal tooth surfaces call for narrow septa, whereas in the presence of an extremely convex tooth surface, wide interdental septa with flat crests are found.

• both statements are true The junctional epithelium consists of a collarlike band of stratified squamous nonkera tinizing epithelium. It is three to four layers thick in early life, but the number of layers in creases with age to 10 or even 20 layers. Also, the junctional epithelium tapers from its coronal end, which may be 10 to 29 cells wide to one or two cells at its apical termination, located at the CEJ in healthy tissue. These cells can be grouped in two strata; the basal layer facmg trie connective tissue and the suprabasal layer extending to the tooth surface. Note: The length of the junctional epithelium ranges from 0.25 to 1.35 mm (average is 0.97 mm). The junctional epithelium is formed by the confluence of the oral epithelium and the reduced enamel epithelium during tooth eruption. However, the reduced enamel epithelium is not es sential for its formation; in fact, the junctional epithelium is completely restored after pocket instrumentation or surgery, and it forms around an implant. The junctional epithelium is attached to the tooth surface (epithelial attachment) by means of an internal basal lamina. It is attached to the gingival connective tissue by an external basal lamina. The internal basal lamina consists of a lamina densa (adjacent to the enamel) and a lamina lucida to which hemidesmosomes are attached. Hemidesmosomes have a decisive role in the firm attachment of the cells to the internal basal lamina on the tooth surface^ «w For a new attachment to form after periodontal treatment, the following must occur: '|/\t 1. Complete removal of calculus, altered cementum, diseased junctional epithelium, antral pocket epithelium 2. Need undifferentiated mesenchymal cells Important: The junctional epithelium in disease (which is referred to as a long junctional ep ithelium) is different from the junctional epithelium in health. In disease, migration of the junctional epithelium occurs, along with degeneration in the connective tissue under the at tachment; as the junctional epithelium proliferates along the root surface (gets longer), the coronal portion detaches. Barrier membranes, which are often used to treat bony defects, help to prevent this long junctional epithelium from forming. pdl/g

~~Which of the following types of oral mucosa is not keratinized under normal conditions?~~

~~• buccal mucosa~~

~~• vermillion border of the lips~~

~~• hard palate~~

~~• gingiva~~

~~pdl/g~~

~~The narrowest band of attached gingiva is found:~~

~~on the lingual surfaces of maxillary incisors and the facial surfaces of maxillary first molars~~

~~• on the facial surfaces of mandibular second premolars and the lingual surface of canines~~

~~• on the facial surfaces of the mandibular canine and first premolar and the lingual surfaces adjacent to the mandibular incisors and canines~~

~~• none of the above~~

115 copyright © 2013-2014 - Dental Decks PERIODONTICS • buccal mucosa The three functional types of oral mucosa are lining, masticatory, and specialized mucosa. These terms provide functional descriptions of the oral mucosa in specific locations. • Masticatory mucosa: covers the gingiva and hard palate. - Epithelium: it has a keratinized or parakeratinized stratified squamous epithelium. - Lamina propria: has two layers: a thick papillary layer of loose connective tissue and a deep reticular layer of dense connective tissue. • Lining mucosa: covers all of soft tissue of the oral cavity except the gingiva, hard_rjalate, and dorsal surface of the tongue. - Ejplthelium: Generally, the epithelium of the lining mucosa is nonkeratinized. Qalfae^ver- millipn.border of the lip, however, it is keratinized. If subject to unusual frictional stress, the epithelium may become parakeratinized or keratinized. Other cells found in the epithelium of the lining mucosa are Langerhans cells, melanocytes, and Merkel cells. - Lamina propria: Under the epithelium of the lining mucosa, a loose connective tissue with thin collagen fibers forms a papillary lamina propria that carries blood vessels, lymphatic ves sels, and nerves. - Submucosal Adistinct submucosa underlies the lining mucosa, except on the inferior of the tongue. The submucosa contains large bands of collagen and elastic fibers that bind the mucosa "trTtne underlying muscle. The submucosa also contains the larger nerves, blood vessels, and lymphatic vessels that supply the neurovascular networks of the lamina propria throughout the oral cavity. In the lips, tongue, and cheeks, the submucosa contains many minor slaivary glands. - Specialized mucosa: is restricted to the dorsal surface of the tongue, and is characterized by the presence of surface papillae of several types and by taste buds in the epithelium^ The ep ithelium is keratinized. Important: All oral mucosa, whether keratinized, nonkeratinized, or parakeratinized, is of the stratified squamous type of epithelium and the underlying central core of connective tissue. Al though the epithelium is predominantly cellular in nature, the connective tissue is less cellular and composed primarily of collagen fibers and ground substance.

~~• on the facial surfaces of the mandibular canine and first premolar and the lingual surfaces adjacent to the mandibular incisors and canines~~

*** Narrow gingival zones may occur also at the mesiobuccal root of maxillary first molars, associated with prominent roots and sometimes with bony dehiscences, and at the mandibular third molars.

The width of the attached gingiva is determined by subtracting the sulcus or pocket depth from the total width of the gingiva (gingival margin to mucogingival line). This is done by stretching the lip or cheek to demarcate the mucogingival line while the pocket is being probed. The amount of attached gingiva is generally considered to be insufficient when stretching of the lip or cheek induces movement of the free gingival margin.

The width of the attached gingva on the facial aspect differs in different areas of the mouth. It is generally greatest in the incisor region (3.5-4.5 mm in maxilla, 3.3-3.9 mm in mandible), and narrower in the posterior segments (1.9 mm in maxillary and 1.8 mm in mandibular first premolars) ."*'*

Important: A "functionally adequate" zone of gingiva is defined as one that is kera tinized, firmly bound to tooth and underlying bone,*about 2.0 mm or more in width, and resistant to probing and gaping when the lip or cheek is distended.

1. The "attached" gingiva is structured to withstand frictional stresses of mas- Notes tication and brushing. 2. The alveolar mucosa appears to be well adapted to permit movement but is not able to withstand frictional stresses. pdl/g . • •. are the most common cells in the peridontal ligament and appear as ovoid or elongated cells oriented along the principal fibers, exhibiting pseudopodialike processes.

~~• cementoblasts~~

~~• osteoblasts~~

~~• fibroblasts~~

~~• macrophages~~

~~pdl/g~~

~~Bone consists of:~~

~~• two-thirds organic matter and one-third inorganic matrix~~

~~• one-third organic matter and two-thirds inorganic matrix~~

~~• one-half organic matter and one-half inorganic matrix~~

~~• two-thirds inorganic matter and one-third organic matrix~~

117 copyright © 2013-2014 - Dental Decks PERIODONTICS • fibroblasts Types of cells identified in the periodontal ligament: • Connective tissue cells fvflrjroblasts, cignientoblasts, and osteoblasts. Fibroblasts are the most common cells; they synthesize collagen and possess the capacity to phagocytize "old" collagen fibers. Note: Cementoclasts and osteoclasts are also seen in the cemental and osseous surfaces of the PDL. • Epithelial rest cells: the epithelial rests of Malassez form a latticework in the PDL and are con sidered remnants of Hertwig root sheath, which disintegrates during root development. They are distributed close to the cementum throughout the PDL of most teeth and are most numerous in the apical and cervical areas. ^ • ^^ • Defense cells: includeWrtrophils, lymphocytes, macrophages, mast cells, and eosinophils. These cells, as well as those associated with neurovascular elements, are similar to the cells in other connective tissues. The functions of the periodontal ligament are categorized into: Physical: attachment of the tooth to the bone via principal fibers and the absorption of occlusal forces. Formative: formation of connective tissue components by activities of connective tissue cells (cementoblasts, fibroblasts, and osteoblasts). Remodeling: by activities of connective tissue cells that are able to form as well as resorb ce mentum (cementoblasts or cementoclasts), the PDL (fibroblasts orfibroclasts), and the alveolar bone (osteoblasts or osteoclasts). Nutritive: through blood vessels that maintain the vitality of its various cells. Sensory: carried by the trigeminal nerve, proprioceptive and tactile sensitivity is impartedI through PDL (sensation of contact between teeth). Note: The PDL also contains a large proportion of ground substance, filling the spaces between the fibers and cells. It consists of two main components: glycosaminoglycans, such as hyaluronic acid jmd proteoglycans, and glycoproteins, such as/ibronectin and laminin. The PDL may also contain calcified masses called cementicles, which are adherent to or detached from the root surfaces. These develop from calcified epithelial rests.

~~• two-thirds inorganic matter and one-third organic matrix~~

The alveolar process is the portion of the maxilla and mandible that forms and supports the tooth sockets (alveoli). It forms when the tooth erupts to provide the osseous attachment to the forming PDL; it disappears gradually after the tooth is lost. The alvolar process consists of the following: • An external plate of cortical bone formed by haversian bone and compacted bone lamellae. • The inner socket wall of thin, compact bone called the alveolar bone proper is seen as the lam ina dura in radiographs. Histologically, it contains a series of openings (cribriform plate) through which neurovascular bundles link the PDL with the central component of the alveolar bone, the cancellous bone. • Cancellous trabeculae, located between the two compact layers, acts as supporting alveolar bone. The interdental septum consists of cancellous supporting bone enclosed within a com pact border. In addition, the bones of the jaw include thebasal bone, which is the portion of the jaw located api cally but unrelated to the teeth. Most of the facial and lingual portions of the sockets are formed by compact bone alone; cancel lous bone surrounds the lamina dura in apical, apicolingual, and interradicular areas. Osteoblasts, the cells that produce the organic matrix of bone, are differentiated from pluripotent follicle cells. Alveolar bone is formed during fetal growth by intramembranous ossification and con sists of a calcified matrix with osteocytes enclosed within spaces called lacunae. Bone consists of two-thirds inorganic matter and one-third organic matrix. The inorganic matrix is composed principally of the minerals calcium and phosphate, along with hydroxyl, carbonate, cit rate, and trace amounts of other ions, such as sodium, magnesium^ and fluoride. The mineral salts are in the form of hydroxyapatite crystals and constitute approximately two thirds of the bone structure. The organic matrix consists mainly of collagen type I (90%), with small amounts of noncollage- nous proteins such as osteocalcin, osteonectin, bone morphogenetic protein, phosphoproteins, and proteoglycans. Although the average width of the periodontal ligament space is documented to be about , considerable variation exists.

~~• 0.002 mm~~

~~• 0.2 mm~~

~~• 2.0 mm~~

~~• 20 mm~~

~~The principal fibers of the peridontal ligament are composed mainly of colla gen type III.~~

~~The amount of collagen in a tissue can be determined by its glycine content.~~

~~• both statements are true~~

~~• both statements are false~~

~~• the first statement is true, the second is false~~

~~• the first statement is false, the second is true~~

***The periodontal space is diminished around teeth that are not in function and in unerupted teeth, but it is increased in teeth subjected to hyperfunction.

The periodontal ligament is composed of a complex vascular and highly cellular connec tive tissue that surrounds the tooth root and connects it to the inner wall of the alveolar bone. It is continuous with the connective tissue of the gingiva and communicates with the marrow spaces through vascular channels in the bone.

The PDL is abundantly supplied with sensory nerve fibers capable of transmitting tactile, pressure, and pain sensations by the trigeminal pathways. Nerve bundles pass into the PDL from the periapical area and through channels from the alveolar bone that follow the course of the blood vessels. The bundles divide into single myelinated fibers, which ulti mately lose their myelin sheaths and end in one of four types of neural termination:

1. Free endings, which have a treelike configuration and carry pain sensation. 2. Ruffini-like mechanoreceptors, located primarily in the apical area. 3. Coiled Meissner corpuscles, also mechanoreceptors, found mainly in the midroot region. 4. Spindlelike pressure and vibration endings, which are surrounded by a fibrous capsule and located mainly in the apex. A J *

~~Note: Orthodontic treatment is possible because the PDL continuously responds and changes as a result of the functional requirements imposed on it by externally applied forces.~~

~~• both statements are false~~

Collagen is synthesized by fibroblasts, chondroblasts, osteoblasts, odontoblasts, and other cells. The several types of collagen are all distinguishable by their chemical composition, distribution, function, and morphology. The principal fibers of the periodontal ligament are composed mainly of collagen type I, whereas reticular fibers are composed of colla gen type III. Collagen type IV is found in the basal lamina.

Collagen is a protein composed of different amino acids, the most important of which are glycine, pro fine, hydroxylysine, and hydroxyproline. The amount of collagen in a tisue can be determined by its hydroxyproline content. Collagen is responsible for maintenance of the framework and tone of tissue.

1. Less regularly arranged collagen fibers are found in the interstitial connective Notes tissue between the principal fiber groups; this tissue contains the blood vessels, lymphatics, and nerves. 2. Although the PDL does not contain mature elastin, two immature forms are found; oxytalan and eluanin. The so-called oxytalan fibers run parallel to the root surface in a vertical direction and bend to attach to the cementum in the cer vical third of the root. They are thought to regulate vascular flow. 3. The principal fibers are remodelled by the PDL cells to adapt"to physiologic needs and in repsonse to different stimuli. A/An of the saliva causes precipitation of calcium phosphate salts by lowering the precipitation constants.

~~• decrease in the pH~~

~~• increase in the pH~~

~~• decrease in the viscosity~~

~~• increase in the viscosity~~

~~pdl/g~~

~~The sulcular epithelium is a:~~

~~• thick, keratinized stratified squamous epithelium without rete pegs~~

~~• thick, nonkeratinized stratified squamous epithelium with rete pegs~~

~~• thin, keratinized nonstratified squamous epithelium with rete pegs~~

~~• thin, nonkeratinized stratified squamous epithelium without rete pegs~~

The theoretic mechanisms by which plaque becomes mineralized can be grouped into two main cat egories: 1 .Mineral precipitation results from a local rise in the degree of saturation of calcium and phos phate ions, which may occur through the following mechanisms: • An increase in the pH of the saliva causes precipitation of calcium phosphate salts by low ering the precipitation constants. The pHaaajUje_devated by the losj»of carbon dioxide and the fojaaation of ammonia by dental plaque bacteria. • Colloidal proteins in saliva bind calcium and phosphate ions and maintain a supersaturated solution with respect to calcium phosphate salts. With stagnation of saliva, colloids settle out, and the supersaturated state is no longer maintained, leading to precipitation of calcium phos phate salts. • Phosphatase liberated from dental plaque, desquamated epithelial cells, or bacteria precip itates calcium phosphate by hydrolyzing organic phosphates in saliva, thus increasing the con centration of free phosphate ions. 2. Seeding agents induce small foci of calcification that enlarge and coalesce to form a calcified mass. This concept is referred to as the epjtactic concept, or more appropriately, heterogenous jjLUcleation. It is suspected that the intercellular matrix of plaque plays an active role as the seed ing agent. The carbohydrate-protein complexes may initiate calcification by removing calcium from saliva (chelation) and binding with it to form nuclei that induce subsequent deposition of minerals. Note: Mineralization of plaque starts extracellularly around both gram-positive and gram-nega tive organisms.(^acderion^^fsvd.yeillonella species have the ability to form intracellular hy droxyapatite crystals. Remember: Materia alba is a concentration of njjcroorganisms, dgsquamated epithelial cells, leukocytes, and amixture of salivary proteins and lipids, with few or no food particles, and it lacks the regular internal pattern observed in plaque.

~~thin, nonkeratinized stratified squamous epithelium without rete pegs~~

The epithelial component of the gingiva shows regional morphologic variations that reflect tis sue adaptation to the tooth and alveolar bone. These variations include: • Oral (outer) epithelium: covers the crest and outer surface of the marginal gingiva and the surface of the attached gingiva. On average, the oral epithelium is 0.2 to 0.3 mm in thickness. It is keratinized or parakeratinized. The oral epithelium is composed of four lay ers: stratum basale. stratum spinosum, stratum granulosum, and stratum.cprneum. • Sulcular epithelium: lines the gingival sulcus; it is a thin, nonkeratinized stratified squa mous epithelium without rete pegs, and it extends from the coronal limit of the junctional epithelium to the crest of the gingival margin. • Junctional epithelium: consists of a collarlike band of stratified squamous jtonksra- tinizing epithelium. It is three to four layers thick in early life, but the number of layers in creases with age to 10 or even 20 layers. Also, the junctional epithelium tapers from its coronal end, which may be 10 to 29 cells wide to one or two cells at its apical termination, located at the CEJ in healthy tissue. These cells can be grouped in two strata; the basal layer facing the connective tissue and the suprabasal layer extending to the tooth surface. The length of the junctional epithelium ranges from fL21.fo..l..3.5 mm. Important: The attachment of the junctional epithelium to the tooth is reinforced by the gin gival fibers, which brace the marginal gingiva against the tooth surface. For this reason, the junctional epithelium and the gingival fibers are considered a functional unit, referred to as the dentogingival unit. Note: Histologically, the best way to distinguish the free gingiva from the epithelial attach ment is the fact that the epithelium of the epithelial attachment does not contain rete pegs and the free gingiva does. Rete pegs are epithelial projections that extend into the gingival con nective tissue. Connective tissue projections that extend into the overlying epithelium are called connective tissue papillae. p/c >ental plaque is composed primarily of:

~~• microorganisms~~

~~• water~~

~~• minerals~~

~~• tissue cells~~

~~P/c The source of mineralization for supragingival calculijsis :~~

~~• desquamated epithelial cells~~

~~• gingival crevicular fluid~~

~~• phosphatases formed by bacterial plaque~~

~~• saliva~~

~~123 copyrights > 2013-2014 -Dental Decks PERIODONTICS • microorganisms~~

Dental plaque is defined clinically as a structured, resilient, yellow-grayish substance that adheres tena ciously to the intraoral hard surfaces, including removable and fixed restorations. Plaque is primarily composed of bacteria in a matrix of salivary glycoproteins and extracellular poly saccharides. The micoroorganisms exist within an intercellular matrix that also contains a few host cells, such as epithelial cells, macorphages, and leukocytes.

Dental plaque is broadly classified as: •\Supragingival plaquejfis found at or above the gingival margin; when in direct contact with the gin gival margin" it is referred to as marginal plaque. Gram-positive cocci and short rods predominate at the tooth surface, whereas gram-negative rods and filaments, as well as spirochetes, predominate in the outer surface of the mature plaque mass. •..Subgingival plaque: is found below the gingival margin, between the tooth and the gingival pocket epithelium. In general, the subgingival microbiota differs in composition from the supragingival plaque, primarily because of the local availability of blood products and the low oxidation-reduction (redox) potential, which characterizes the anaerobic environment. • Cervical plaque: - Tooth associated: gram-positive rods and cocci - Tissue associated: gram-negative rods and cocci, filaments, flagellated rods, and spirochetes • Deeper parts of the pocket: - Tooth associated: gram-negative rods - Tissue associated: gram-negative rods, flagellated rods, and spirochetes. Filamentous organ isms become fewer. Key point:The composition of the subgingival plaque depends on the pocket depth. The apical part is dominated by spirochetes, cocci, and rods, whereas in the poronaLpart, more filaments are observed. Important: The overall pattern observed in dental plaque development shows a shift from the early aer obic environment characterized by gram-positive facultative species to a highly oxygen-deprived envi ronment in which gram-negative anaerobic microorganisms predominate.

~~• saliva~~

Calculus is dental plaque that has undergone mineralization. It forms on the surfaces of natural teeth and dental prostheses. Saliva is the source of mineralization for supragingival calculus, whereas the serum transudate called gingival crevicular fluid furnishes the miner als for subgingival calculus. • Supragingival calulus: is located coronal to the gingival margin. It is usally white or pale yellow in color and is hard with a claylike consistency. It is easily removed by a professional cleaning. The two most common locations for supragingival calculus to develop are the buccal surfaces of the maxillary molars and the lingual surfaces of the mandibular anterior teeth. Saliva from the parotid gland flows over the facial surfaces of the maxillary molars through Stensen duct, whereas the orifices of Wharton duct and Bartholin duct empty onto the lingual surfaces of the mandibular incisors from the submandibular and sublingual glands, respectively. • Subgingival calculus: is located below the crest of the marginal gingiva. It is typically hard and dense and frequently appears dark brown or greenish black (due to exposure to gin gival crevicular fluid) while being firmly attached to the tooth surface. Differences in the manner in which calculus is attached to the tooth surface affect the relative ease or difficulty encountered in its removal. It has been shown that calculus can attach to tooth surfaces through four modes: L Attachment by.means of an organic pellicle on enamel: most common mode 2. Mechanical locking into surface irregularities 3. Close adaptation of calculus undersurface depressions to the gently sloping mounds of the unaltered cementum surface 4. Penetration of calculus bacteria into cementum Important: A reduction in gingival inflammation and probing depths with a gain in clinical attachment can be observed after removal of subgingival plaque and calculus. p/c

~~Specific bacteria are implicated in periodontal disease and are commonly found at the site of infection. The Red complex bacteria consist of the following. Select all that apply.~~

~~• porphyromonas gingivalis~~

~~• tannerella forsythia~~

~~• treponema denticola~~

~~• eikenella corrodens~~

~~p/c~~

~~Nearly all human oral bacteria exhibit, j cell-to-cell recognition of genetically distinct cell types.~~

~~• adhesion~~

~~• pleomorphism~~

~~• coaggregation~~

~~• organization~~

~~125 copyright O 2013-2014 - Dental Decks PERIODONTICS • porphyromonas gingivalis Rzditannerell a forsythia •Treponema denticola~~

Recent sudies of plaque samples looking for 40 subgingival microorganisms using a DNA hybridization methodology, defined "complexes" of periodontal microorganims. The composition of the different complexes was based on the frequency with which different clusters of microorganisms were recovered. The early (pri mary) colonizers are either independent of defined complexes (Actinomyces naeslundii, A. viscosus) or mem bers of the yellow (Streptococcus spp.) or purple complexes (Actinomyces odontolyticus). The microorganisms primarily considered secondary (late) colonizers fell into the green, orange or red com plexes. The green complex includes Eikenella corrodens, Actinobacillus actinomycetemcomitans serotype a, and Capnocytophaga species. The orange complex includes Fusobacterium, Prevotella, and Campylobacter species. The green and orange complexes include species recognized as pathogens in periodontal and nonpe- riodontal infections. The red complex consists of Porphyromonas gingivalis, Treponema denticola, and Tan nerella forsythia. This complex is of particular interest because it is associated with bleeding on probing, which is an important clinical parameter of destructive periodontal diseases. Plaque as a biofllm: The dental plaque biofilm has a similar structure to all biofilms (composed of micro- colonies encased in a polysaccharide matrix). It is heterogenous in structure, with clear evidence of open fluid- filled channels running through the palque mass. These water channels permit the passage of nutrients and other agents throughout the biofilm, acting as a primitive "circulatory" system. The intercellular matrix con sists of organic and inorganic materials derived from saliva, gingival crevicular fluid, and bacterial products.

Important: In a biofilm, bacteria have the capacity to communicate with each otherfcalled quorum sensing).: This involves the regulation of expression of specific genes through the accumulation of signaling compounds that mediate intercellular communication. When these signaling compounds reach a threshold level (called quorum cell density), gene expression can be activated. Note: The high density of bacterial cells in a biofilm also facilitates the exchange of genetic information among cells of the same species and across species and even genera. Conjugation, transformation, plasmid transfer, and transposon transfer have all been shown to occur more easily in a biofilm. Remember: Following a prophy, plaque is most likely to accumulate on the interproximal tooth surfaces first.

~~• coaggregation~~

The process of plaque formation can be divided into three major phases: 1. The formation of the pellicle on the tooth surface: all surfaces of the oral cavity are coated with a pellicle (the initial phase of plaque development). Within nanoseconds after vigorously polishing the teeth, a thin, saliva-derived layer called the acquired pellicle, covers the tooth sur face. This pellicle conists of numerous components, including glycoproteins (mucins), proline- rich proteins, phosphoproteins (e.g., statherin), histidine-rich proteins, enzymes (e.g., 'atpha-amylase), and other molecules that can function as adhesion sites for bacteria (receptors). Note: The mechanisms involved in enamel pellicle formation include electrostatic, van der Waals, and hydrophobic forces. 2. Initial adhesion and attachment of bacteria: - Phase 1: Transport to the surface: involves the initial transport of the bacterium to the tooth surface. - Phase 2: Initial adhesion: results in an initial, reversible adhesion of the bacterium, medi ated through van der Waals and electrostatic forces. - Phase 3: Attachment: after initial adhesion, a firm anchorage between bacterium and sur face will be established. - Phase 4: Colonization of the surface and biofilm formation: read #3 below 3. Colonization and plaque maturation: When the firmly attached microorganisms start grow ing and the newly formed bacterial clusters remain attached, mjcrofipjonies or a biofilm can de velop. From this stage forward, new mechanisms are involved because new intrabacterial connections may occur. At least 18 genera from the oral cavity have shown some form of coag- ., greagation (cell-to cell recognition, of genetically distinct partner cell types). Essentially all oral bacteria (but especially Fusobacterium nucleatum) possess surface rnplecules that foster some type of cell-to-cell interaction. This process occurs primarily through the highly specific stere ochemical interaction of protein and carbohydrate molecules located on the bacterial cell sur faces, in addition to the less specific interactions resulting from hydrophobic, electrostatic, and van der Waals forces. At least two-thirds of the inorganic component of calculus is crystalline in structure. Of the four main crystal forms, which one is more common in the mandibular anterior region?

~~magnesium whitlockite~~

~~brushite~~

~~octcalcium phosphate~~

~~• hydroxyapatite~~

~~Early or young plaque consists primarily of~~

~~• filaments~~

~~• cocci~~

~~• rods~~

~~• vibrios~~

127 copyright O 2013-2014 - Dental Decks • brushite Supragingival calculus consists of inorganic (70%-90%) and organic components. The inor ganic portion consists of 76% calcium phosphate, 3% calcium carbonate, and traces of mag nesium phosphate, and other metals. The principal inorganic components are calcium (39%); phosphorus (19%); carbon dioxide (1.9%); magnesium (0.8%); and trace amounts of sodium, zinc, strontium, bromine, copper, manganese, tungsten, gold, aluminum, silicon, iron, and flu orine. At least two-thirds of the inorganic component is crystalline in structure. The four main crystal forms are as follows: • Hydroxyapatite (58%) • Magnesium whitlockite (21%) • Octacalcium phosphate (12%) • Brushite (9%>) Generally, two or more crystal forms are typically found in a sample of calculus. Hydroxya patite and octacalcium phosphate are detected most frequently (in 97% to 100% of all supragingival calculi) and constitute the bulk of calculus. Bjrai&hjte is more common in the mandibular anterior region and magnesium whitlockite in the posterior areas. The organic component of supragingival calculus consists of a mixture of protein-polysaccharide complexes, desquamated epithelial cells, leukocytes, and various types of microor ganisms. The composition of subgingival calculus is similar to that of supragingival calculus, with some differences. Subgingival calculus has the same hydroxyapatite content, more magne sium whitlockite, and less brushite.and octacalcium than supragmgival"calculus. The ratio of calcium to phosphorus is higher subgingivally, and the sodium content increases with the depth of periodontal pockets. Salivary proteins present in supragingival calculus are not found sub gingivally. Note: Calculus (both supragingival and subgingival) located on interproximal surfaces can be seen on bite-wing radiographs as interproximal spurs.

• COCCI Bacterial plaque is the primary etiologic factor for the initiation of periodontal disease. Plaque formation be gins immediately after a tooth surface is cleaned. The rate of plaque formation is affected by diet, age, salivary flow, oral hygiene, tooth alignment, systemic disease, and host factors. Changes in the types of organisms occur within plaque as the plaque matures. • Days 1 to 2: young plaque consists primarily of cocci (i.e., Streptococcus mutans and sanguis) • Days 2 to 4: cocci still dominate but there are increasing numbers oifjJamgrtous forms and slender rods. Gradually the filamentous forms replace many of the cocci. • Days 4 to 7: filaments increase in numbers, and a more mixed flora begins to appear with rods, filamen tous forms, and fusobacteria. • Days 7 to 14: vibrios and spirochetes appear, and the number of white blood cells increases. More gram- negative and anaerobic organisms" appear. The signs of inflammation are beginning to be observable in the gingiva. • Days 14 to 21: vibrios and spirochetes are prevalent in older plaque, along with filamentous forms. Gin givitis is evident clinically. As plaque ages: • The number of cocci decreases and the number of rods, fusiform, filaments, and spirochetes increases • The number of aerobic bacteria decreases and the number of anaerobic bacteria increases • The number of gram-positive organisms decreases and the number of gram-negative organisms increases Key point: As the biofilm (plaque) matures, there is a shift from a predominance of facultative, gram-posi tive bacteria to gram-negative, anaerobic bacteria. The transition from gram-positive to gram-negative microorganisms observed in the structural develop ment of dental plaque is paralleled by a physiologic transition in the developing plaque. The early col onizers (e.g., Streptococci, Actinomyces species) use oxygen and lower the redox potential of the environment, which then favors the growth of anaerobic species. Gram-positive species use sugars as an energy source and saliva as a carbon source. The bacteria that predominate in mature plaque are anaer obic and asaccharolytic and use amino acids and small peptides as energy sources. 1. The organic constituents of plaque include polysaccharides (dextran), proteins (i.e., albumin), Notes glycoproteins (from saliva), and lipid material. 2. The inorganic components of plaque are predominantly calcium and phosphorus, with trace amounts of other minerals, including sodium, potassium, and fluoride. 3.The source of inorganic constituents of supragingival plaque is primarily saliva. poc/fur

~~When evaluating an osseous defect, the only way to determine the number of walls left surrounding the tooth is by:~~

~~periodontal probing~~

~~radiographs~~

~~exploratory surgery~~

~~> testing for mobility~~

~~poc/fur~~

~~Angular defects are classified on the basis of:~~

~~• the number of osseous walls that were destroyed by periodontal disease~~

~~• the number of osseous walls left surrounding the tooth~~

~~• the number of osseous walls that will remain after surgery~~

~~• periodontal probe readings~~

*** This is because a dense buccal and/or lingual plate of bone will tend to mask the defect, blocking it out on the radiographs. This information can only be determined by exploratory surgery.

~~Important: Radiographs will not show: 1 • The.number ofwajlsjeft surrounding the tooth 2. The exact configuration of the defect 3. The location of the epithelial attachment~~

Remember: The two most critical parameters for the prognosis of a periodontally involved tooth are mobility and attachment loss (which is most critical). Angular defects are classi fied on the basis of the number of osseous walls. Angular defects may have one, two, or three walls. The number of walls in the apical portion of the defect may be greater than that in its occlusal portion, in which case the term "combined osseous" defect is used.

Pocket depth is the distance between the base of the pocket and the gingival margin. The level of attachment, on the other hand, is the distance between the base of the pocket and a fixed point on the crown, such as the CEJ. Changes in the level of attachment can be caused only by gain or loss of attachment and thus provide a better indication of the degree of peri odontal destruction.

Pocket formation causes loss of attachment of the gingiva and denudation of the root surface. The severity of the attachment loss is generally, but not always, correlated with the depth of the pocket. This is because the degree of attachment loss depends on the location of the base of the pocket on the root surface, whereas the pocket depth is the distance between the base of the pocket and the crest of the gingival margin. Pockets of the same depth may be associa ted with different degrees of attachment loss and pockets of different depths may be associat ed with the same amount of attachment loss.

~~• the number of osseous walls left surrounding the tooth~~

Horizontal bone loss is the most common pattern of bone loss in periodontal disease. The bone is re duced in height, but the bone margin remains approximately perpendicular to the tooth surface. The in terdental septa and facial and lingual plates are affected, but not necessarily to an equal degree around the same tooth. Vertical or angular defects are those that occur in an oblique direction, leaving a hollowed-out trough in the bone alongside the root; the base of the defect is located apical to the surrounding bone. In most instances, angular defects have accompanying intrabony periodontal pockets; intrabony pockets, how ever, always have an underlying angular defect. Angular defects are classified on the basis of the number of osseous walls. Angular defects may have one, two, or three walls. The number of walls in the apical portion of the defect may be greater than that in its occlusal portion, in which case the term "combined osseous defect" is used. Important: Surgical exposure is the only sure way to determine the presence and configuration of vertical osseous defects. 1. Osseous craters are concavities in the crest of the interdental bone confined within the fac- Notes ialana lingual walls. Craters have been found to make up about one-mird (35.2%,) of all def ects and about two-third_s (62%) of all mandibulardefects. They are more common in post- terior segments tKarTTrTanterlor segments. They are best treated with osseous surgery (rec ontouring). 2.The relative degree of success of periodontal bone grafting is reported to vary directly with the number of bony walls of the defect (vascularized, osseous surface area) and inversely with the surface area of the root against which the graft is implanted. Thus, a narrow, three- walled angular defect usually yields the greatest succsess, a two-walled defect the next best, and a one-walled defect the least. 3. A dehiscence is a loss of the buccal or lingual bone overlaying the root portion of a tooth, leaving the area covered by soft tissue only. 4. The three-wall vertical defect was originally called an intrabony defect. The term "intra bony" was later expanded to designate all vertical defects. 5. The one-wall vertical defect is also called a hemiseptum. ~$^2iprabon y pockets are associated with horizontaU?one loss. Tijexar^jyEryrrtaossMus. poc/fur The principal differences between intrabony and suprabony pockets are the relationship of the soft tissue wail of the pocket to the alveolar bone, thepat- tern of bone destruction, and the direction of the transseptal fibers of the periodontal ligament.

~~In intrabony pockets, the base of the pocket is apical to the crest of the alve olar bone, and the pocket wall lies between the tooth and the bone.~~

~~• both statements are true~~

~~• both statements are false~~

~~• the first statement is true, the second is false~~

~~• the first statement is false, the second is true~~

~~poc/fur~~

~~Which type of pocket is formed by gingival enlargement without destruction of the underlying periodontal tissues?~~

~~gingival pocket~~

~~• periodontal pocket~~

~~• suprabony pocket~~

~~• intrabony pocket~~

Distinguishing Features of Suprabony and Intrabony Periodontal Pockets Suprabony Pocket Intrabony pocket 1. Base of pocket is coronal to level of alveolar 1. Base of pocket is apical to crest of alveolar bone so that bone. the bone is adjacent to soft tissue wall. 2. Pattern of destruction of underlying bone is 2. Pattern of bone destruction is vertical (angular) horizontal. 3. Interproximally, transseptal fibers that are 3. Interproximally, transseptal fibers are oblique rather than restored during progressive periodontal disease horizontal. They extend from cementum beneath base of are arranged horizontally in the space between pocket along alveolar bone and over crest to the base of pocket and alveolar bone. cementum of adjacent tooth 4. On facial and lingual surfaces, periodontal 4. On facial and lingual surfaces, periodontal ligament fi ligament fibers beneath pocket follow their bers follow angular pattern of adjacent bone. They normal horizontal-oblique course between the extend from cementum beneath base of pocket along tooth and bone. alveolar bone and over crest to join with outer periosteum.

~~Reproduced with permission, from Newman MG, Takei HH, Klokkevold PR, Carranza FA. Carranza's Clinical Periodontology,10th ed. Elsevier, 2006.~~

~~• gingival pocket~~

~~Deepening of the gingival sulcus may occur by coronal movement of the gingival mar gin, apical displacement of the gingival attachment, or a combination of the two processes.~~

Pockets can be classified as follows: • Gingival pocket. (pseudopocket): this type of pocket is formed by gingival enlarge ment without destruction of the underlying periodontal tissues. All gingival pockets are suprabony (the base of the pocket is coronal to the crest of the alveolar bone). The sul cus is deepened because of the increased bulk of the gingiva. • Periodontal pocket: this type of pocket occurs with destruction of the supporting periodontal tissues. Progressive pocket deepening leads to destruction of the support ing periodontal tissues and loosening and exfoliation of the teeth. Two types of periodontal pockets exist: • Intrabony (infrabony, subcrestal, or intra-alveolar): in which the bottom of the pocket is apical to the level of the adjacent alveolar bone • Suprabony (supracrestal or supra-alveolar): in which the bottom of the pocket is coronal to the underlying alveolar bone. Clinical signs that suggest the presence of periodontal pockets include a bluish red, thick ened marginal gingiva; a bluish red, vertical zone from the gingival margin to the alveo lar mucosa; gingival bleeding and suppuration; tooth mobility, diastema formation; and symptoms such as localized pain or "pain deep in the bone." The only reliable method of locating periodontal pockets and determining their extent is careful probing of the gingi val margin along each tooth surface. poc/fur

~~Furcation involvements have been classified as grades I, II, III, and IV accord ing to the amount of tissue destruction. Grade II is:~~

~~• incipient bone loss~~

~~• partial bone loss (cul-de-sac)~~

~~> total bone loss with through-and-through opening of the furcation~~

~~• similar to the above, but with gingival recession exposing the furcation to view~~

~~poc/fur~~

~~In intrabony pockets:~~

~~• the bone loss is vertical in nature~~

~~• the bone loss is horizontal in nature~~

~~• transseptal fibers are horizontal~~

~~• supracrestal fibers follow the normal bone contour~~

The term furcation involvement refers to the invasion of the bifurcation and trifurcation of multirooted teeth by periodontal disease. The denuded furcation may be visible clinically or covered by the wall of the pocket. The extent of involvement is determined by exploration with a blunt probe, along with a simultaneous blast of warm air to facilitate visualization. Furcation involvements have been classified as grades I, II, III, and TV according to the amount of tissue destruction. • Grade I: is incipient bone loss • Grade II: is partial bone loss (cul-de-sac) • Grade III: is total bone loss with through-and-through opening of the furcation • Grade IV: is similar to Grade III, but with gingival recession exposing the furcation to view Findings that complicate furcation involvement and account for some painful symptoms in clude caries of the cementum and dentin, tooth resorption in the furcation, abscess formation • llX'ri"lll'l*l"l'r"* I^TM—«^MI"H l—'l * M1" "ft r* Ill"" I I Mil MM fill II !•••!! ' in the furcation, and involvement of the pulp via lateral canals in the furcation. Definitive di agnosis of furcation involvement is made by careful clinical probing. X-rays are helpful but only as an adjunct to the clinical examination. The major principle of treatment of involved furca is to eliminate the involvement whenever possible. A variety of methods are available for treatment. Not all of them provide for elimi nation of the furcation; some provide only for increased accessibility for plaque removal. Bone grafts have relatively little effectiveness in treating furcations. However, guided tissue re generation is used to treat Grade II furcations with good success. Note: Furcation involvement iror f maxillary second molars have the poorest prognosis following therapy- f-f^' Important: Microscopically, furcation involvement presents no unique pathologic features. It is simply a phase in the rootward extension of the periodontal pocket.

~~• the bone loss is vertical in nature~~

~~ABC~~

Different types of-periodontal pockets. A, Gingival pocket. There is no destruction of the supporting periodontal tissues. B, Suprabony pocket. The base of the pocket is coronal to the level of the underlying bone, Bone loss is horizontal. C, Intrabony pocket. The base of the pocket is apical to the level of the adjacent bone. Bone loss is vertical. poc/fur

~~Drug-induced gingival enlargement consists of a pronounced hyperplasia of the connective tissue and epithelium.~~

~~Drug-induced gingival enlargement may occur in mouths with little or no plaque and may be absent in mouths with abundant deposits.~~

~~• both statements are true~~

~~• both statements are false~~

~~• the first statement is true, the second is false~~

~~• the first statement is false, the second is true~~

~~When using the periodontal probe to measure pocket depth, the measure ment is taken from the:~~

~~• base of the pocket to the CEJ~~

~~• free gingival margin to the CEJ~~

~~• junctional epithelium to the margin of the free gingiva~~

~~« base of the pocket to the mucogingival junction~~

136 copyright © 2013-2014- Dental Decks PERIODONTICS • both statements are true Gingival enlargement is a well-known consequence of the administration of some anticonvul sants, immunosuppressants, and calcium channel blockers. Clinical and microscopic features of the enlargements caused by the different drugs are similar. The growth starts as a painless, beadlike enlargement of the interdental papilla and extends to the facial and lingual gingival margins. As the condition progresses, the marginal and papillary en largements unite; they may develop into a massive tissue fold covering a considerable portion of the crowns, and may interfere with occlusion. When uncomplicated by inflammation, the lesion is mulberry-shaped, firm, pale pink, and re silient, with a minutely lobulated surface and no tendency to bleed. The presence of the enlarge ment makes plaque control difficult, often resulting in a secondary inflammatory process that complicates the gingival overgrowth caused by the drug. Secondary inflammatory changes not only add to the size of the lesion caused by the drug, but also produce a red or bluish-red discol oration, obliterate the lobulated surface demarcations, and increase bleeding tendency. Anticonvulsants: the first drag-induced gingival enlargements reported were those produced by phenytoin (Dilantin). Other hydantoins known to induce gingival enlargement are ethotoin (Peganone) and mephenytoin (Mesantoin). Other anticonvulsants that have the same side effect are the succinimides (ethosuximide [Zarontin], methsuximide [Celontin], and valproic acid [De pakene]). Immunosuppressants: Cyclosporine is a potent immunosuppressive agent used to prevent organ transplant rejection and to neat several diseases of autoimmune origin. Cyclosporine-induced gin gival enlargement is.more vascularized than phenytoin enlargement. Another immunosuppressive drug, tacrolimus, has been used effectively and results in much less gingival overgrowth. Calcium channel blockers are drugs developed for the treatment of cardiovascular conditions. These drugs are the dihydropyridine derivatives (amlodipine [Lotrel, tiorvasc],felodipine [Plendil], nicardipine [Carden], nifedipine [Adalat, Procardia]); the benzothiazine derivatives (diltiazem [Cardizem, Dilacor-XR, Tiazac]); and the phenylalkylamine derivatives (verapamil [Calan, Isoptin, Verelan, Covera-HS]).

~~• junctional epithelium to the margin of the free gingiva~~

Periodontal probes are used to measure the depth of pockets and to determine their con figurations. The typical probe is a tapered, rodlike instrument calibrated in millimeters, with a blunt, rounded tip. Ideally, probes are thin, and the shank is angled to allow easy insertion into the pocket. The probe is inserted along the long axis of the tooth into the pocket with a firm, gentle pressure (approximately 10 to 20 grams) until resistance is met. The probe is walked around each surface of the tooth. This method is less painful and more efficient, provides a complete and accurate assessment of the depth of the epithelial attachment and will detect bony defects better.

Periodontal probing provides the most accurate assessment of periodontal pocket depth. The true topography of vertical osseous defects cannot be determined by radiographic ex amination alone. Bone levels may be high, yet pockets may be deep. Extensive bone loss may exist and, yet, be unaccompanied by pockets if the gingiva has receded. The most important reason for using the periodontal probe is that it determines the loss of at tachment.

1. Bleeding scores: bleeding is still the most reliable indicator of the presence Notes of gingival or periodontal inflammation. ISftW 2. Plaque score: with plaque disclosing solution, used to help visualize plaque for the patient and clinician. Also used at multiple visits to show patients im provement in their level of oral hygiene. 3. Recession is measured in millimeters from the CEJ to the marginal gin giva of each tooth root. How should a periodontal probe be adapted in an interproximal area?

~~> it should be parallel to the long axis of the tooth at the point angle~~

~~• it should be parallel to the long axis of the tooth at the contact area~~

~~• it should touch the contact area and the tip should angle slightly beneath and beyond the contact area~~

~~• it should be perpendicular to the long axis of the tooth in front of the contact area~~

~~prob~~

~~How should the periodontal probe be inserted into the sulcus?~~

~~• perpendicular to the long axis of the tooth~~

~~• with a firm pushing motion~~

~~• with a short oblique stroke~~

~~• parallel to the tooth surface~~

138 copyright e 2013-2014 - Dental Decks PERIODONTICS • it should touch the contact area and the tip should angle slightly beneath and beyond the contact area *** The periodontal probe may be angled approximately 10° on each interproximal sur face so that the tip of the probe is placed apical to the contact point of adjacent teeth and may detect any interdental crater, but, in most instances, the direction of the probing is par allel to the long axis of the tooth.

Periodontal measurements are taken by inserting the probe under the marginal gingiva and gently moving it down to the junctional epithelium (feels soft, elastic, and resilient). In a healthy site, the tip of the probe stops within the junctional epithelium and, in a dis eased site, it penetrates into the connective tissue. In severe disease, the probe tip may pen etrate to the alveolar bone.

1. The clinical probing depth is always greater than the histologic sulcus or Notes pocket depth. Probing accuracy is only within +/- 1 mm. 2. The calibrated periodontal probe should have a tapered shaft approximately 0.5 mm in diameter at the tip. It is important to have uniform instruments throughout the practice to ensure as much standardization as possible. 3. Furcation areas can be best evaluated with the curved #2 Nabers probe. t%/Yh& periodontal probe can also be useful in the detection of subgingival de posits.

~~• parallel to the tooth surface~~

The tip of the probe should always be kept in contact with the tooth, thus preventing soft tissue injury. The probe is gently "walked" along the junctional epithelium in an up-and- down motion (called circumferential probing), always remaining under the gingival margin. It is imperative that the probe be walked along the entire gingival sulcus since the depth of the epithelial attachment varies. Six measurements are recorded - three from the buccal and three from the lingual: distobuccal, buccal, mesiobuccal, distolingual, lin gual, and mesiolingual. These measurements are the distance in millimeters from the base of the pocket (junctional epithelium) to the margin of the free gingiva.

1 .The most important reason for using the periodontal probe is that it deter- Notes mines the loss of attachment. These measurements are taken both before and after scaling and root planing procedures to evaluate the tissue response and the effectiveness of treatment. 2. Probing is performed with firm, gentle pressure. The correct probe force (ap proximately 10 to 20 grams) depresses the thumb pad approximatelyJ_mmJo 2 mm. prob

~~If you should meet resistance after inserting the periodontal probe into the sulcus, you should:~~

~~remove the probe and reinsert it in a different spot~~

~~lift the probe away from the tooth and attempt to move it apically~~

~~force the probe beyond the obstruction~~

~~remove the probe and select one with a narrower diameter~~

~~record the measurement where the probe stopped~~

~~prob~~

~~Which of the following is the most common error when performing peri Iodonta l probing? using the wrong type of probe~~

~~incorrectly reading the periodontal probe~~

~~• excessively angling the probe when inserting it interproximally beyond the long axis of the tooth~~

~~• forgetting to also probe the lingual of every tooth~~

Often when probing, the passage of the probe may be blocked by a hard, unyielding ledge. This is usually calculus. Gently lift the probe away from the tooth, placing it against the tissue wall of the pocket and attempt to proceed apically again. If the ob struction was indeed calculus and it has now been bypassed, then the probe should now move deeper into the pocket until the junctional epithelium is reached. The tip of the probe should be placed back against the tooth once the obstruction has been bypassed.

~~Remember: The probe should be inserted parallel to the vertical axis of the tooth and "walked" circumferentially around each surface of each tooth to detect the areas of deepest penetration.~~

1. Recession is the measurement of the migration of the free gingival margin Notes apical to the CEJ of the tooth. Recession is measured as a positive value. The recession measurement added to probe depth at a particular site indicates the amount of periodontal attachment that has been lost at that site. When the gin gival margin is coronal to the CEJ, the recession measurement has a negative value. 2. To measure the amount of attached gingiva: (1) Place the probe on the ex ternal surface of the gingiva and measure from the mucogingival junction to the gingival margin to determine the width of the total gingiva. (2) Insert the probe and measure probing depth. (3) Subtract the probing depth from the total gingi val measurement to get the width of the attached gingiva.

~~• excessively angling the probe when inserting it interproximally beyond the long axis of the tooth~~

*** This will give greater probe readings than are actually present.

Tilting the probe could affect the accuracy of the measurements. If the probe is angled too much, it will extend beyond the contact area, and if it isn't angled enough, then it will be at the line angle instead of under the contact area. Both mistakes will result in inaccurate readings. The tip should be flat against the tooth near the gingival margin with the probe approximately parallel with the long axis of the tooth for insertion.

Note: In the presence of inflammation, the probe may extend apical to.the most coronal extent of the junctional epithelium (bottom of pocket) and give a slightly greater depth than is actually present.

~~Important: If a patient is at risk for subacute bacterial endocarditis, he or she needs to be premedicated before performing periodontal probing. ~\?^"~~

Remember: Bacteremia can occur even with mastication or brushing. However, it does not last long. The important consideration is the presence or absence of periodontal in flammation. The presence of inflammation leads to a longer duration of bacteremia with resultant risks for patients at risk of acute bacterial endocarditis. SDIlNOGOmBd sjpag ieiuaQ - pL0c"-£ LOZ © }i]6uAdo:> ZH

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~~The most accepted theory as to the cause of root sensitivity is the:~~

~~• bayer's theory~~

~~1 chemiosmotic theory~~

~~• hydrodynamic theory~~

~~•quantum theory~~

~~Toothbrush trauma (abrasion) usually occurs on:~~

~~• centrals and laterals~~

~~• canines and premolars~~

~~• second and third molars~~

~~• first and second molars~~

The Hydrodynamic theory postulates that the pain of root sensitivity results from indirect innervation caused by dentinal fluid movement in the tubules, which stimulates mechanoreceptors in the pulp. Root hypersensitivity is a relatively common problem in periodontal practice. It may occur sponta neously when the root becomes exposed as a result of gingival recession or pocket formation, or it may appear after scaling and root planing and surgical procedures. The primary symptom is cold sensitiv ity. Plaque and food debris, if allowed to remain on exposed root surfaces, often lead to increased sen sitivity. Note: To reduce the sensitivity to thermal change after removal of a periodontal dressing, it is best to keep the roots free of plaque. The most common agents used by the patient for oral hygiene are dentifrices. Although many dentifrice products contain fluoride, additional active ingredients for desensitization are strontium chloride, potas sium nitrate, and sodium citrate. The ADA has approved the following dentifrices for desensitizing pur poses: Se«sodyne and ThermoDent, which contain strontium chloride; Qgst Sensitivity Protection, Denquel, and Promise, which contain potassium nitrate; and Protect, wfcrhcontams sodium citrate. Important: Desensitizing agents act through the precipitation of crystalline salts on the dentin surface, which block dentinal tubules. Various office treatments for the desensitization of hypersensitive dentin: • Cavity varnishes • Antiinflammatory agents • Treatments that partially obturate dentinal tubules - Burnishing of dentin - Fluoride compounds - Silver nitrate • Sodium fluoride - Zinc chloride-potassium ferrocyanide • Stannous fluoride - Formalin - Iontophoresis - Calcium compounds: - Strontium chloride • Calcium hydroxide - Potassium oxalate • Dibasic calcium phosphate - Restorative agents - Dentin bonding agents

~~• canines and premola~~

*** Toothbrush trauma (abrasion) usually occurs on teeth that are the most prominent in the dental arch.

The maintenance of oral health is enhanced by the use of a soft-bristle toothbrush with a dentifrice of optimum abrasiveness and a dental floss. A hard-bristle toothbrush is capa ble of causing gingival recession and abrasion of enamel and/or cementum and should be avoided. The abrasive quality of dentifrices affects enamel, but abrasion is more of a concern for patients with exposed dentin because dentin is abraded 25 times faster and cemgjvtjjBi^^jjaesi,,fajs.l;gr than enamel. This can lead to root surface abrasion and root sensitivity Hard tissue damage from oral hygiene procedures is mainly due to abrasive dentifrices, whereas gingival lesions can be produced by the toothbrush alone..*,

Trauma from toothbrushing may result in the following: • Recession of the marginal gingiva • Lacerations of the soft tissues including the attached gingiva and the alveolar mu cosa • V-shaped notches in the cervical areas of teeth • Gingival clefts: narrow grooves that extend from the crest of the gingiva to the at tached gingiva

~~Note: The location of the above alterations is frequently inversely related to the right- or left-handedness of the patient.~~

Remember: In gingival atrophy or recession, the tissue appears to be otherwise nor mal. The gingiva is thin, finely textured and pale pink in color with normal papillae. The gingival sulci are very shallow. Plaque is minimal. it rt sens/rec The most important factor in the control of hypersensitive roots among pat ients with periodontal disease after gingival recession has exposed the cerv ical portions of teeth is:

~~• prescription of home fluoride rinses~~

~~• minimal removal of tooth structure during root planing~~

~~• the application of desensitizing agents that contain fluoride~~

~~• thorough daily plaque control~~

~~scal/rp/gc~~

~~When extensive scaling and root planing must be performed, the best ap proach would be:~~

~~• a series of appointments set up to scale and root plane a segment or quadrant of teeth at a time (thoroughly and completely)~~

~~• gross debridement (sub-and supragingival) of the entire mouth, followed by a series of appointments for fine scaling and polishing~~

~~• perform everything in a single appointment~~

~~• none of the above~~

144 copyright O 2013-2014 - Dental Decks PERIODONTICS ,1 I I •• I • thorough daily plaque contro Sometimes these areas will become sensitive if the root is exposed. The patient will complain of cold sensitivity. The hypersensitivity will sometimes subside in time with daily plaque removal using a soft brush (this will help desensitize the root surface by allowing reminer alization of the root surface). Remember: Gingival recession can also occur secondary to pe riodontal therapy. This may have additional significance in the older patient, namely, increased risk for cervical abrasion and dentinal sensitivity, and most importantly, predisposition to root caries. The acids and toxins produced by the plaque organisms are very irritating to the pulp by way of the odontoblastic processes. This irritation of the pulp heightens its sensitivity to other stim uli. No attempt to reduce hypersensitivity will be successful unless the roots are consistently kept free of plaque. Desensitizing agents can be applied by the patient at home or by the dentist or hygienist in the dental office. The most likely mechanism of action is the reduction in the diameter of the denti nal tubules so as to limit the displacement of fluid in them. This can be attained by: • formation of a smear layer produced by burnishing the exposed surface • topical application of agents that form insoluble precipitates within the tubules • impregnation of tubules with plastic resins • sealing of the tubules with plastic resins The hygienist or dentist should evaluate the brushing technique and monitor hard and soft tis sue conditions at each recall visit. Faulty placement, overaggressive movement or pressure, or the use of a hard toothbrush can lead to hard and soft tissue damage.

~~The most common cause of gingival recession is tooth injury (abrasion). This type of reces sion is common on the left canines of right-handed persons (or right canines of left-handed per sons).~~

~~• a series of appointments set up to scale and root plane a segment or quadrant of teeth at a time (thoroughly and completely)~~

1. There is potential for abscess formation in a deep pocket when only a su- Notes perficial scaling is performed. 2. OHI may be more effective if a patient can see healing tissue in an area that has been completely debrided and compare it to tissue in an untreated area. 3. A patient who has had a gross debridement will see a marked visual im provement of the oral cavity and may not understand the importance and ne cessity of the deep scaling and root planing appointments. This may cause the patient to not follow through with the scheduled treatment, and the pa tient's periodontal condition will be allowed to deteriorate further. 4.Important: Clinical evaluation of the soft tissue response to scaling and root planing, including probing, should not be conducted earlier than 2 weeks post operatively. Reepithelialization of the wounds created during instrumentation takes 1 to 2 weeks. Until then, gingival bleeding on probing can be expected, even when calculus has been completely removed because the_so_ft tissue wound is not epifheliaiized. T.lf any bleeding or swelling is noted in localized areas of the mouth during the reevaluation appointment, check for and remove any residual calculus deposits that might remain. 6. In root planing, ideally, the working stroke should begin at the apical edge of the junctional epithelium (the base of the pocket). Which of the following presents the most difficulty in performing a thorough scaling and root planing?

~~• mesial surfaces of maxillary premolars~~

~~• proximal surfaces of mandibular incisors~~

~~' triturations of maxillary molars~~

~~distal surfaces of mandibular molars~~

~~scal/rp/gc~~

~~Some degree of curettage is done unintentionally when scaling and root plan ing are performed; this is called inadvertent curettage.~~

~~Curettage accomplishes the removal of the chronically inflamed granulation tissue that forms in the lateral wall of the periodontal pocket.~~

~~• both statements are true~~

~~• both statements are false~~

~~• the first statement is true, the second is false~~

~~• the first statement is false, the second is true~~

Mesial surfaces of maxillary premolars and the proximal surfaces of mandibular inci sors are most likely to have flutings. Also, root proximity is a major problem when per forming scaling and root planing on mandibular incisors.. Trifurcations on maxillary first molars are the most difficult of all to root plane.

*** Key point: anatomic features of teeth frequently limit the effectiveness and efficiency of calculus removal.

Remember: If, while root planing, you find only a thin ring of calculus in the bottom third of a deep pocket, you can assume that the calculus previously extended the full length of the pocket but the top part was previously removed. Likewise, if, after scaling and root planing, the patient returns in 1 week with hard, black deposits of calculus around the gingival margin, this indicates that a reduction in inflammation occurred after the proce dure and old calculus is now exposed.

1. The best criterion to evaluate the success of scaling and root planing is no ev- Notes idence of bleeding on probing. Remember: Bleeding on probing indicates in flammation in the tissue. The amount of inflammation present is used to determine the effectiveness of periodontal instrumentation and home care by the patient. 2..Cementum,dfjafcin, and^aleulus are removed during root planing. 3. Tactile sensitivity refers to the ability to distinguish degrees of roughness and smoothness on the tooth surface.

• both statements are true The word curettage is used in periodontics to mean the scraping of the gingival wall of a periodontal pocket to separate diseased soft tissue. Scaling reters to the removal of deposits from the root surface, whereas planing means smoothing the root to remove infected and necrotic tooth substance. A differentiation has been made between gingival and subgingival curettage. •.Gingival curettage: consists of the removal of the inflamed soft tissue.lateral to the pocket wall ^Subgingival curettage: refers to the procedure that is performed apical to the epithelial attachment, severing the connective tissue attachment down to the osseous crest. Indications for curettage are very limited. It can be used after scaling and root planing for the following purposes: "**-<" 1. Curettage can be performed as part of new attachment attempts in moderately deep in trabony pockets located in accessible areas where a type of^efosed" surgery is deemed ad visable. 2. Curettage can be done as a nondefinitive procedure to reduce inflammation before using other methods for pocket elimination or when more aggressive surgical techniques (e.g., flaps) are^entraindicated. 3. Curettage is also frequently performed on recall visits as a method of maintenance treat ment for areas of recjorrent inflammation and pocket depth. Important: Curettage does not eliminate the causes of inflammation (i.e., bacterial plaque and deposits). Therefore, curettaKshouMalwuysbe preceded by scaling and root planing. Note: Gingival curettage always requires some type of local anesthesia The curette is selected so that the cutting edge will be against the tissue (e.g., Gracey #13-14 for distal surfaces, Gracey #11-12 for mesial surfaces). Curettage can also be performed with a 4R-4L Columbia Unjversal curette. scal/rp/gc

~~The main objective of root planing is:~~

~~• to remove chronically inflamed tissues~~

~~• to change the bacterial microflora~~

~~• to remove etiologic agents from the root surface~~

~~• to eliminate pockets~~

~~scal/rp/gc~~

~~Maximum shrinkage after gingival curettage can be expected from tissue that is:~~

~~• fibrotic~~

~~• edematous~~

~~• fibroedematous~~

~~• formed within an intrabony pocket~~

148 copyright © 2013-2014 - Dental Decks PERIODONTICS • to remove etiologic agents from the root surface The major objective of scaling and root planing is to remove etiologic agents that promote gingival inflam mation in the periodontal tissues. Removal of plaque, calculus, and endotoxins results in a subsequent shift from disease-associated, gram-negative anaerobes to health-associated, gram-positive, facultative microorganims. Important: By providing smooth root surfaces, there will be a reduced potential for bacterial accumulation, which is done in an attempt to achieve soft-tissue reattachment. Scaling and root planing are techniques of instrumentation applied to the root surface to divest it of plaque, cal cified deposits, and softened or roughened cementum. When thoroughly performed, techniques produce a smooth, clean, hard polished root surface. Scaling with root planing is the primary treatment for periodon tal inflammation. In simple cases, this treatment is useful in reducing shallow pockets and reducing the num ber of bacteria within these shallow pockets and may be the only treatment necessary. In severely advanced periodontal disease where surgery may not be possible, scaling with root planing is the only treatment feasi ble. Since the removal of plaque and deposits is the definitive treatment for periodontal inflammation, scal ing with root planing is more frequently used than any other type of therapy. The most effective instrument for subgingival scaling and root planing is a sharp curette. They are generally smaller than scalers and are designed to permit atraumatic entry to the subgingival space. The tactile sensitiv ity of most curettes is greater than scalers, and, as such, curettes are well suited for subgingival calculus de tection, calculus removal, and root planing. Each working end has a cutting edge on both sides of the blade and a rounded toe. There are two basic types of curettes: universal and area-specific (Gracey curettes). Double-ended Gracey curettes are paired in the following manner: • Gracey #1-2 and 3-4: anterior teeth • Gracey #5-6: anterior teeth and premolars • Gj^Ci^4Cfi^-affldJi=lfl^4ios.texka:Jeeth:.facial and lingual surfaces • Gracey #11-12: posterior teeth: mesial surface • Gracey #13-14:posterior teeth: distal surface Extended-shank curettes: have a longer terminal shank, a thinned blade, and a large-diameter terminal shank. They are available in finishing for light scaling) or rigid (for removal of heavy or tenacious calculus) designs. Mini-bladed curettes: have shorter blades (half the length) that allow easier insertion and adaptation. Gracey curvettes: are mini-bladed curettes with a more curved blade. Langer and mini-Langer curettes: combine the shank design of Gracey curettes with the universal blade de sign (90-degree angle of the face and lower shank).

• edematous Indications for curettage are very limited. It can be used after scaling and root planing for the following purposes: 1. Curettage can be performed as part of new attachment attempts in moderately deep in trabony pockets located in accessible areas where a type of "closed" surgery is deened ad visable. 2. Curettage can be done as a nondefmitive procedure to reduce inflammation before pocket elimination using other methods or when more aggressive surgical techniques (e.g., flaps) are contraindicated. 3. Curettage is also frequently performed on recall visits as a method of maintenance treat ment for areas of recurrent inflammation and pocket depth. Contraindications of gingival curettage as a definitive procedure include: •™***^Acute periodontal inflammation • Firm, fibrotic tissue • Intrabony pockets • Mucogingival involvements • When the lateral gingival wall is extremely thin 1. Patients with edematous and granulomatous inflammation respond better to Notes curettage than do those with conditions of fibrous hyperplasia. 2. For a new attachment to occur: (1) An adequate number of undifferentiated mesenchymal cells must be present. (2) Complete removal of junctional and pocket epithelium must be accomplished. (3) The complete removal of calculus and/or al tered cementum must be accomplished. Important: It is recommended that all students read The American Academy of Periodon- tology Statement Regarding Gingival Curettage. This can be found on the Internet at: http://www.perio.org/resources-products/pdf/38-curettage.pdf scal/rp/gc

~~Ultrasonic instrumentation is accomplished with a:~~

~~• heavy touch and light pressure, keeping the tip perpendicular to the tooth surface and constantly in motion~~

~~• light touch and heavy pressure, keeping the tip parallel to the tooth surface and stat ionary~~

~~• light touch and light pressure, keeping the tip parallel to the tooth surface and const antly in motion~~

~~• heavy touch and heavy pressure, keeping the tip perpendicular to the tooth surface and stationary~~

~~scal/rp/gc~~

~~Which of the following is the instrument of choice for removing deep sub gingival calculus, for root planing altered cementum, and, for removing the soft tissue lining the periodontal pocket?~~

~~• curette~~

~~• sickle scaler~~

~~• hoe <~~

~~• file~~

150 copyright © 2013-2014 - Dental Decks PERIODONTICS • light touch and light pressure, keeping the tip parallel to the tooth surface and constantly in motion Ultrasonic instruments have been widely used as a valuable adjunct to conventional hand instru mentation for many years. The selection of either ultrasonic or hand instrumentation should be de termined by the clinician's preference and experience and the needs of each patient. The success of either treatment method is determined by the time devoted to the procedure and the thorough ness of root debridement. In practice, clinicians typically use a combination of both ultrasonic and hand instrumentation to achieve thorough debridement. Ultrasonic instrumentation is accomplished with a light touch and light pressure, keeping the tip parallel to the tooth surface and constantly in motion. Leaving the tip in one place for too long or using the point of the tip against the tooth can produce gouging and roughening of the root sur face or overheating of the tooth. The working end of the ultrasonic instrument must come in con tact with the calculus deposit to fracture and remove it. The working tip must contact all aspects of the root surface to remove plaque and toxins thoroughly. Although as much as 1 Ommor more of the length of the ultrasonic tip vibrates, only a small portion of it can be adapted to contact the curved root surface at any one time or point. As with hand instruments, a series of focused, over lapping strokes must be activated to ensure complete root coverage. Important: Subgingival root surface roughness does not seem to interfere with healing after scal ing and root planing. Thus, it does not appear useful to reinstrument root surfaces with hand in struments after a clinically detectable smooth surface has been created with sonic or ultrasonic scaler. Contraindications to the use of ultrasonic and sonic scaling devices: ^-01der cardiac pacemakers vMSiown communicable diseases that can be transmitted by aerosols ^Patients at risk for respiratory disease, including patients who are immunosuppressed or have chronic pulmonary disorders •^Patients with titanium implants, porcelain or bonded restorations (unless you use plastic- tipped inserts)

• curette Each working end of a curette has a cutting edge on both sides of the blade and a rounded toe. The curette is finer than the sickle scalers and does not have any sharp points or corners other than the cutting edges of the blade. Therefore, curettes can be adapted and provide good access to deep pockets, with minimal soft tissue trauma. In cross section, the blade appears semicircular with a convex base. The lateral bor der of the convex base forms a cutting edge with the face of the smemicircular blade. There are cutting edges on both sides of the blade. There are two basic types of curettes: • Universal curettes: have cutting edges that may be inserted in most areas of the dentition by alter ing and adapting the finger rest, fulcrum, and hand position of the operator. The blade size and the angle and length of the shank may vary, but the face of the blade of every universal curette is at a 90- degree angle (perpendicular) to the lower shank when seen in cross section from the tip. The blade of the universal curette is curved in one direction from the head of the blade to the toe. • Area-Specific curettes: Gracey curettes are representative of the area-specific curettes, a set of sev eral instruments designed and angled to adapt to specific anatomic areas of the dentition. The Gracey curettes also differ from the universal curettes in that the blade is not at a 90-degree angle to the lower shank. The term offset blade is used to describe Gracey curettes, because they are angled approxi mately 60 to 70 degrees from the lower shank. 1. Using curettes with short, even working strokes followed by longer ones is the most effect- Notes ive and efficient way of performing root planing. The correct cutting edge can be seen as a larger, outer curve. 2. Final root planing strokes are longer and lighter than scaling strokes. 3. Root planing strokes become lighter as the cementum becomes smoother. 4. Exploratory scaling and root planing strokes differ in angulation, pressure, length, and direction. Remember: To establish the correct working angle once a curette is inserted subgingivally, the shank must be moved away from the tooth to open the angle of the blade to the tooth surface. At proper working angulation (less.than.90° but more than 45°), the lower shank of a.Gracey curette is parallel to the tooth surface being scaled. The lower shank of a universal curette would be tilted slightly toward the tooth. scal/rp/gc

~~In magnetostrictive ultrasonic units the pattern of vibration of the tip is linear.~~

~~In piezoelectric ultrasonic units the pattern of vibration of the tip is elliptical.~~

~~• both statements are true~~

~~• both statements are false~~

~~• the first statement is true, the second is false~~

~~• the first statement is false, the second is true~~

~~scal/rp/gc~~

If a patient experiences sensitivity while being scaled with an ultrasonic scal ing device, all of the following actions will be appropriate to counter this problem EXCEPT two. Which two are inappropriate?

~~• proceeding to another tooth and then returning to the sensitive tooth later in the appointment~~

~~• moving the instrument slower~~

~~• making necessary adjustments to the water spray~~

~~• turning up the power of the device~~

~~• using less pressure~~

152 copyright © 2013-2014 - Dental Decks PERIODONTICS • both statements are false The two types of ultrasonic units are magnetostrictive and piezoelectric. In both types, alternating elec trical current generates oscillations in materials in the handpiece that cause the scaler tip to vibrate. De pending on the manufacturer, these ultrasonic vibrations at the tip of the instruments of both types range from 20,000 to 45,000 cycles per second. In magnetostrictive units, the pattern of vibration of the tip is elliptical, which means that all sides of the tip are active and will work when adapted to the tooth. In piezoelectric units, the pattern of vibration of the tip is linear, or back and forth, meaning that the two sides of the tip are the most active. Sonic units consist of a handpiece that attaches to a compressed air line and uses a variety of specially designed tips. Vibrations at the sonic tip range from 2-flUO. to tiSOOrjTs which provides less power for cal culus removal than ultrasonic units. Ultrasonic and sonic tips are designed to operate in a wet field with a water spray directed at the end of the tip. Within the water droplets of this spray mist are tiny vacuum bubbles that quickly collapse, re leasing energy in a process known as cavitation. The cavitating water spray serves to flush calculus, plaque, and debris dislodged by the vibrating tip from the pocket. Mag>cjtjictiye ultrasonic tips gen erate heat and require this water for cooling. Sonic and piezoelectric units do not generate this heat but still utilize water for cooling frictional heat and flushing away debris. Rental Endoscope: this device consists of a resusable fiberoptic endoscope over which is fitted a dis posable sterile sheath. It fits onto periodontal probes and ultrasonic instruments that have been designed to accept it. This device allows clear visualization deeply into subgingival pockets and furcations. It per mits operators to detect the presence and location of subgingival deposits. EVA system (enhanced visual assessment): this system uses motor-driven diamond files to correct over hanging or overcontoured proximal alloy or resin restorations. Prophy-Jet air-powder polishing device: was the first specially designed handpiece to deliver an air- powered slurry of warm water and sodium.bic.arbonate for polishing. It is very effective for the removal of extrinsic stains and soft deposits. Note: Polishing powders containing aluminum trihydroxide or other substances rather than sodium bicarbonate are being used to offset the abrasive effect of sodium bicar bonate on restorations as well as dentin and cementum. Contraindications to the use of air-powered pol ishing devices are those patients with respiratory illnesses, hejnodialysis, hypertension, and infectious diseases. .

~~• moving the instrument slower • turning up the power of the device~~

*** The opposite of these is true!! All of the rest are appropriate actions to be considered in that situation.

If sensitivity is encountered during use: • Lighten the pressure • Adjust the water spray: increase water flow to cool the tip • Move to another tooth and then return later to the sensitive tooth •Decrease the power

~~Power-driven instruments work best with quick hand movement ~ rapid, controlled movements.~~

~~Remember: *** The ultrasonic principle is based on the use of high-frequency sound waves. scal/rp/gc~~

~~Air is used to deflect the free gingival margin to detect:~~

~~• the CEJ~~

~~• smooth root surfaces~~

~~• subgingival calculus~~

~~• inflammation~~

~~scal/rp/gc~~

~~The primary function of which instrument is to fracture or crush large deposits of tenacious calculus?~~

~~• hoe scalers * • files~~

~~• chisel scalers~~

~~• quetin furcation curettes~~

One of the uses of the air syringe is to detect calculus, both supra- and subgingival. Supragingival calculus is often seen more easily when it is dry (saliva often conceals it), and deflecting the free gingival margin slightly makes subgingival calculus easier to de tect.

When using the explorer to detect calculus, a light instrument grasp should be utilized to increase tactile sensitivity. The lateral side of the tip of the instrument should be placed in contact with the tooth surface when exploring for calculus. Dried calculus is easier to detect than wet calculus with the explorer because it is less slippery.

~~• files~~

The five basic scaling instruments are as follows: > •(Curette) the curette is the instrument of choice for removing deep subgingival calculus, root planingVrtered cementum, and removing the^stoft tissue lining the periodontal pocket. Each working end has a cutting edge on both sides of the blade and a rounded toe. The curette is finer than the sickle scalers and does not have any sharp points or corners other than the cutting edges of the blade. Therefore, curettes can be adapted and provide good ac cess to deep pockets with minimal soft tissue damage. -• Sickle sc&ler&supragingival scalers): have a flat surface and two cutting edges that con verge in a sharply pointed tip. The shape of the instrument makes the tip strong so that it will not break off during use. The sickle scaler is used primarily to remove supragingival cal culus. r- * Files: have a series of blades on a base. Their primary function is to fracture or crush large deposits of tenacious calculus or burnished sheets of calculus. Files" can easily gouge and roughen root surfaces when used improperly. Therefore, they are not suitable for fine scal ing and root planing. '•Chisel scalers:, are designed for the proximal surfaces of teeth too closely spaced to per mit the use of other scalers and are usually used in the anterior part of the mouth. They are double-ended instruments with a curved shank at one end and a straight shank at the other; the blades are slightly curved and have a straight cutting edge beveled at 45 degrees. The chisel is inserted from the facial surface. The instrument is activated with aEushnujtion, while the side of the blade is held firmly against the root. |jT.oe scalerp are used for scaling.ofled^esjjrringsof calculus. The blade is bent at a 99- degree angle; the cutting edge is formed by the junction of the flattened terminal surface with the inner aspect of the blade. The cutting edge is beveled at 45 degrees. Note: McCall's #3, 4, 5, 6, 7, and 8 are a set of six hoe scalers designed to provide access to all toomsurfaces. Each instrument has a different angle between the shank and handle. scal/rp/gc

~~While scaling subgingivally, the tip of the curette breaks off. All of the fol lowing are appropriate actions to take to try and remove this tip EXCEPT one. Which one is the EXCEPTION!~~

~~• use a push stroke to force the tip out of the sulcus~~

~~• gently examine the gingival sulcus~~

~~• take a periapical radiograph of the area~~

~~• place the patient in an upright position scal/rp/gc~~

~~While scaling subgingivally, the tip of the curette breaks off. All of the fol lowing are appropriate actions to take to try and remove this tip EXCEPTone. Which one is the EXCEPTION!~~

~~use a push stroke to force the tip out of the sulcus~~

~~gently examine the gingival sulcus~~

~~• take a periapical radiograph of the area~~

~~• place the patient in an upright position~~

~~scal/rp/gc~~

~~It is impossible to carry out peridontal procedures efficiently with dull instru ments.~~

~~A sharp instrument cuts more precisely and quickly than a dull instrument.~~

~~• both statements are true~~

~~• both statements are false~~

~~• the first statement is true, the second is false~~

~~• the first statement is false, the second is true~~

156 copyright © 2013-2014 - Dental Decks PERIODONTICS • use a push stroke to force the tip out of the sulcus *** Never use a push stroke, this could force the tip further into the sulcus. Gently examine the sulcus using a curette in a spoon-like stroke, attempting to pull the fragment out. The procedure should be stopped immediately and the patient placed in an upright position. Be fore proceeding subgingivally, check the floor of the mouth and the mucobuccal fold for the frag ment. A periapical radiograph should then be taken before going any further to locate the fragment. Try not to alarm the patient. The last thing you want is for the patient to become frantic. The best way to prevent curette breakage is to use proper sharpening techniques to maintain the original instrument design and to discard instruments when the blade starts to thin out. A thinner blade is weaker and will break more easily. Remember: The Schwartz PeriotrieverS;are highly magnetized instruments designed for the re trieval of broken instrument tips from the periodontal pocket. \x^

Comparison of Area-Specific (Gracey) and Universal Curettes Gracey Curette Universal Curette Area of use Set of many curettes, designed for One curette designed for all areas and surfaces specific areas and surfaces Cutting Edge Use One cutting edge used; work with Both cutting edges used; work with either outer outeredge only or inner edge Curvature Curved in two planes; blade curves Curved in one plane; blade curves up, not to the uEandiaJJSJMe side Blade angle Offset blade; face of blade beveled Blade not offset; face of blade beveled at 90 at 60 degrees to shank degrees to shank

~~• both statements are true~~

To do its job at all, a dull instrument must be held more firmly and pressed harder than a sharp instru ment. This reduces tactile sensitivity and increases the possibility that the instrument will inadvertently slip. The objective of sharpening is to restore the fine, thin, linear cutting edge of the instrument. This is done by grinding the surfaces of the blade until their junction is once again sharply angular rather than rounded. It is important to restore the cutting edge without distorting the original angles of the instrument. When these angles have been altered, the instrument does not function as it was designed to function, which limits its effectiveness. Principles of sharpening: • Choose sharpening stone appropriate for instrument (flat, cone, coarse, etc.) • Use a sterilized sharpening stone if the instrument to be sharpened will not be resterilized before it is used on a patient . • Establish the proper angle between the stone and the surface of the instrument • Maintain a stable, firm grasp of both the instrument and the sharpening stone • Avoid excessive pressure • Avoid formation of a "wire edge," which is produced when the direction of the sharpening stroke is away from, rather tharTinto or toward, the cutting edge. When back-and-forth or up-and-down sharpemng strokes are used, formation of a wire edge can be avoided by finishing with a down stroke toward the cutting edge. • Lubricate the stone during sharpening. Oil should be used for natural stones and water for synthetic stones • Sharpen instruments at first sign of dullness Note: The technique for sharpening a universal curette can be used to sharpen a Gracey curette. How ever, bear in mind that the Gracey's cutting edge is offset and it also curves, unlike the universal's cut ting edge. Remember: India and Arkansas oilstones are examples of natural abrasive stones. Carborundum, ruby, and ceramic stones are synthetically produced. scal/rp/gc

~~When sharpening, a wire edge is produced:~~

~~• only when using a coarse artificial stone~~

~~• when using a mounted ruby stone only~~

~~• when no oil is used for lubrication of the stone~~

~~• when the last stroke of the stone is drawn away from the cutting edge~~

~~scal/rp/gc~~

~~A curette designed to scale and root plane anterior teeth with deep pockets will have a:~~

~~• short, straight shank~~

~~• long, straight shank~~

~~• short, angled shank~~

~~• long, angled shank~~

Avoid formation of a "wire edge," which is produced when the direction of the sharpening stroke is away from, rather than into or toward, the cutting edge. When back-and-forth or up-and-down sharpening strokes are used, formation of a wire edge can be avoided by finishing with a down stroke toward the cutting edge. '^'J^^iU)MipgllllWflllWW™r~^^ The cutting edge of an instrument is formed by the angular junction of two surfaces of its blade. The cutting edges of a curette, for example, are formed where the face of the blade meets the lat eral surfaces. When the instrument is sharp, this junction is a fine line running the length of the cut ting edge. As the instrument is used, metal is worn away at the cutting edge, and the junction of the face and lateral surface becomes rounded or dulled. Thus, the cutting edge becomes a rounded sur face rather than an acute angle.

Sharpening stones can be categorized by their method of use: • Mounted rotary stones: these stones are mounted on a metal mandrel and used in a motor- driven handpiece. They may be cylindrical, conical, or disc-shaped. These stones are generally not recommended for routine use because they (1) are difficult to control precisely, (2) tend to wear down the instrument quickly, and (3) can generate considerable frictional heat, which may affect the temper of the instrument. • Unmounted stones: come in a variety of sizes and shapes. Unmounted stones may be used in two ways: the instrument may be stabilized and held stationary while the stone is drawn across it, or the stone may be stabilized and held stationary while the instrument is drawn across it. 1. The optimal internal angle between the face of the Wade and the lateral surface of Notes a universal curette and a Gracey curette is 70° to 80°. fSg$*i>*** 2. An instrument whose cutting edge is 90° or more will slip over calculus deposits and requires heavy lateral pressure to remove calculus deposits. 3. The best grasp to use when holding an instrument to be sharpened is the palm grasp.

~~• long, straight shank~~

How an instrument shank is designed influences the intended use of the instrument. It is rec ommended that an instrument with a rigid shank be used for removal of heavy calculus de posits. *** Straight shames are used in the anterior areas and contra:angled shanks areja^m the posterior areas. Rigid, thick shank: • Stronger • Less flexible • Provides less tactile sensitivity • Stronger instruments are needed for heavy calculus removal Less rigid, more flexible shank: • Provides more tactile sensitivity • Used for removing fine calculus and for root planing Important: The Gracey curettes differ from the universal curettes in that the blade is not at a 90-degree angle to the lower shank. The term offset blade is used to describe Gracey curettes, because they are angled approximately 60 to 70 degrees from the lower shank. ^/ ^ttgulatinn}efers to the angle between the face of the bladed instrument and the tooth surface°ltJtnayalso be called the tooth-blade relationship. During scaling and root planing, op timal angulation is between 45: and 90 degrees. With angulation of less than 45 degrees, the cutting edge will not bite into or engage the calculus properly. Instead, it will slide over the calculus, smoothing or "burnishing" it. If angulation is more than 90 degrees, the lateral sur face of the blade, rather than the cutting edge, will be against the tooth, and the calculus will not be removed and may become burnished. Q^ Note: When gingival curettage is indicated, angulation greater than 90 degrees is deliberately established so that the cutting edge will engage and remove the pocket lining. scal/rp/gc

~~are used selectively on line angles 01 negotiated with other strokes. — •~~

~~• vertical strokes~~

~~• oblique strokes~~

~~• horizontal strokes~~

~~• circular strokes~~

159 copyright © 2013-2014 - Dental Decks PERIODONTICS • horizontal strokes There are three basic strokes used during instrumentation. Any of these basic strokes may be activated by a pull or a push motion in a vertical, oblique, or horizontal direction. Vertical and oblique strokes are used the most frequently. Horizontal strokes are used selectively on line angles or deep pockets that can not be negotiated with vertical or oblique strokes. The direction, length, pressure, and number of strokes necessary for either scaling or root planing are determined by four major factors: (1) gingival position and tone, (2) pocket depth and shape, (3) tooth contour, and (4) the amount and nature of the calculus or roughness., • Exploratory stroke: is a light, "feeling" stroke that is used with probes and explorers to evaluate the~dimensions of the pocket and to detect calculus and irregularities of the tooth surface. The instru ment is grasped lightly and adapted with light pressure against the tooth to achieve maximal tactile sensitivity. • Scaling stroke: is a short, powerful pull stroke that is used with bladed instruments for the removal of both supragingival and subgingival calculus. The scaling motion should be initiated in the forearm and transmitted from the wrist to the hand with a slight flexing of the fingers. The scaling stroke is not initiated in the wrist or fingers nor is it carried out independently without the use of the forearm. • Root planing stroke: is a moderate to light pull stroke that is used for final smoothing and planing of the root surface. With a moderately firm grasp, the curette is kept adapted to the tooth with even, lateral pressure. A continuous series oflong, overlapping shaving strokes is activated. As the surface becomes smoother and resistance diminishes, lateral pressure is progressively reduced. 1. "Pulling" strokes are safer than "pushing" strokes because the push stroke may force cal- Notes cuius into the supporting tissues. The push stroke, especially in an apical direction, is not t recommended. 2. Probing stroke: upward and downward movement within a periodontal pocket. 3. The modified pen grasp is the most useful grasp for periodontal instrumentation. 4. The lower third of the working end, which is the last few millimeters adjacent to the toe or tip, must be kept in constant contact with the tooth while it is moving over the tooth. 5. For subgingival insertion of a bladed instrument such as a curette, angulation should be as close to 0 degree as possible. During scaling and root planing, optimal angulation is be tween 45 and 90 degrees.