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 copyright e 2013-2014 - Dental Decks PERIODONTICS 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 interradic- ular 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 3 copyright © 2013-2014 - Dental Decks PERIODONTICS 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*<P • Autogenous bone grafts: ^> , ^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.