IMPLANT

Tooth Extraction—An Opportunity for Site Preservation

or a patient, the loss of a tooth flat basilar bone.9-11 induces not only emotional Alveolar bone survives only in the Ftrauma but also physical presence of dentition. The existence deformity. Removal spurs bone of intact teeth in a partially edentu- resorption, which increases over lous ridge defies or at least delays the time. As the soft-tissue drape follows sort of severe loss reported above Michael Sonick, DMD the osseous contour, such remodel- because the bone remains to support Director of Sonick Seminars ing may result in a depressed mucos- them; this is the concept fundamental Private Practice 8 Periodontics and Implant Dentistry al profile, especially if a thin biotype to the use of overdentures. Despite Fairfield, Connecticut exists. This becomes a possible visu- adjacent teeth, some level of resorp- Phone: 203.254.2006 al concern. Immediately after extrac- tion occurs after the removal of 1 Email: [email protected] Web site: www.sonickdmd.com tion, the socket walls undergo inter- tooth, depending on a host of factors. nal and external turnover, resulting These influencing variables include: Board Member Contemporary Esthetics in crestal bone loss as well as hori- • Anatomy. A thicker, wider ridge zontal reduction. Buccolingual loss tends to resorb less, possibly overall exceeds that in the vertical because of higher vascularity. As it direction, though both occur. Several is typically thinner, the buccal wall investigations report horizontal and diminishes more than the lingual vertical deficits of 3.0 mm to 6.0 mm 2 to 4 months after tooth removal. and 1.0 mm to 2.0 mm, respectively, It experiences 56% horizontal re- per site after an initial healing period sorption compared to 30% vertical of 4 months.1-5 and is in a position roughly 2.0 mm Debby Hwang, DMD The newly edentulated jaw apical to its lingual counter- 12,13 Private Practice exhibits 10 times more resorption in part. A naturally thin wall Fairfield, Connecticut the first year than in those subse- encloses fewer vessels and marrow 203.254.2006 quent, with 4 times greater mandibu- spaces for regeneration and may Email: [email protected] 6 Web site: www.sonickdmd.com lar reduction than maxillary. Up to be easily broken (see Trauma). 25% horizontal and 4.0 mm vertical • Trauma. Fracture of the alveolus loss occurs within the first year.7,8 In sustained before or during extrac- 3 years, ridge volume diminishes by tion will lead to greater osseous 40% to 60%.8 After 25 years, the resorption. Iatrogenic buccal plate mandible loses nearly 8.0 mm of height damage from surgery may occur without teeth. A ridge with long-term and hinders ideal healing. Re- edentulism may be comprised of just moval of an ankylosed tooth often

38 CONTEMPORARY ESTHETICS | FEBRUARY 2007 necessitates extensive preparation not have restoration performed? Steps for Socket Preservation around it, again generating fur- Regardless of the prosthetic plan for 1. Flap design—Perform a sulcular ther bone loss. the newly edentulous area, it is better incision circumferentially around • Pathology. Any infective process, to have more bone present than less. the tooth with scalpel to sever soft- including periodontitis and peri- A patient with no immediate plans tissue fibers (Figures 3B and 6B). odontal or endodontic abscesses, for any type of tooth replacement in Try not to raise a flap unless the destroys bone. Patients with the site may change his or her plans buccal plate is not intact or surgical severe as time passes. For those who seek extraction is necessary. First, probe demonstrate little initial bone rehabilitation with removable partial to determine the existence of labial around the extracted tooth and , a bulkier ridge improves bone (Figure 6C). If a flap must be adjacent teeth, thus complicating force distribution as well as mechani- raised, perform an envelope flap repair and restoration. In addi- cal support and retention. A wider (no verticals) by extending the sul- tion, cysts, tumors, or congenital pontic site eases restorability and cular incision to the mesial or distal disorders may instigate loss. esthetics for conventional fixed par- of the adjacent teeth. Vertical inci- • Genetic predisposition. It is probable tial denture fabrication. Last, a site sions may compromise the blood that genetics affect the healing planned for implant replacement supply, but if one is anticipated, sequence but it is unknown how requires a ridge with enough verti- place it in the manner demonstrat- exactly or to what extent. Some cal and horizontal proportions for ed (Figure 6D). patients naturally possess less stability and proper mucosal con- 2. Atraumatic removal of tooth— osteoclastic activity than others. tour. The absolute minimum Remember that atraumatic equals • Medical status and drugs. Me- amount of bone surrounding an removal of no bone from the tabolic diseases, especially if implant on the buccal or lingual is extraction site. Section any multi- poorly controlled, alter tissue 1.0 mm, but in the anterior zone, at rooted tooth with a long carbide turnover. Diabetes, for instance, least 2.0 mm of facial bone must bur to separate the roots. Use a disturbs collagen turnover and occur to resist recession.22 periotome to sever the periodontal bone formation.14 Habits such as If retaining as much bone as ligament (PDL) fibers from the smoking similarly interrupt wound possible is preferable, how do we tooth. Insert the device into the healing.15,16 Smoking increases the combat the natural resorption that PDL space at the line angles and risk for localized alveolitis postex- occurs postextraction? That is, how palatally, parallel to the root, apply traction as well.17,18 One class of do we maintain the bone already apical force incrementally. The bone-sparing drugs, IV bisphos- present? Termed “ridge preserva- periotome should advance further phonates, may be associated with tion” or “socket preservation,” this apically with time. If more mobili- the development of osteonecrosis, procedure of site maintenance usu- ty is required, elevate the root gen- especially after dental procedures. ally involves the major steps listed tly with a small straight or Molt Current guidelines suggest that below. The general goal is to pre- elevator. If a root remains recalci- patients on these medications vent resorption and not necessarily trant to multiple applications of cannot undergo elective dental to augment the ridge, though this these methods or if ankylosis is sus- procedures.19-21 may be a desired secondary goal. pected, use of a long, thin diamond Preservation upholds enough bone bur is suggested. Apply a bur to the Extraction Socket Remodeling to facilitate an uncomplicated Stage PDL space around the tooth. Extraction socket remodeling 1 surgery (Figures 1 and 2). Most Remove loosened roots with an is complex. But why does bone studies on this subject attempt elevator or forceps. resorption matter from a clinical preservation, not enhancement at 3. Degranulation—Remove soft tissue standpoint? Is preservation of a site the time of extraction, and this will and debris with curettes and necessary if the patient elects to be the focus of this article as well. Neumeyer bur application. This

CONTEMPORARY ESTHETICS | FEBRUARY 2007 39 IMPLANT DENTISTRY

bur will remove soft tissue but bony crest or further coronally if made, primary closure may occur leave hard structures intact. Irrigate desired (Figures 3D and 4A). by creating a split-thickness dissec- with saline or 0.12% 5. Membrane application—If the buccal tion at the thick, apical aspect of solution. wall is thin or not intact, contain the flap (periosteal release). The 4. —If the socket does not the bone graft with a membrane of tissue may be advanced over the bleed, decorticate it apically with a choice placed on the buccal wall socket. If this is the goal, make sure small round bur to induce bleed- (Figure 7A). Make sure it is at least there is no tension of the flap. ing. Be careful not to fenestrate the 1.0 mm away from the necks of the Perform further periosteal release buccal or lingual wall or penetrate adjacent teeth, though it may con- as necessary. If no vertical incisions surrounding structures (eg, teeth, tact the roots. If desired, the buccal were made, place a collagen plug sinus, etc). Place graft material of wall may be built up 1.0 mm to 2.0 on top of the socket to cover the choice into the socket. Condense mm horizontally with more bone bone graft. The plug may be flat- gently with a cotton tip applicator graft material under the membrane. tened to enhance surface area or instrument handle. Fill up to the 6. Closure—If vertical incisions were (Figures 4B and 4C). The plug

Each figure contains four panels. Starting from the top left and proceeding clockwise, these are designated from A to D.

Figure 1— A: A parulis at the apex of tooth Figure 2—A: Maxillary teeth. B: Ridge Figure 3—A: Tooth No. 7. B: Sulcular incision No. 9, which exhibits endodontic failure. B: preservation performed with FDBA and performed. C: Atraumatic removal of tooth Socket preservation performed with freeze- collagen plugs contained with 4-0 expanded and degranulation. D: Placement of FDBA dried bone allograft (FDBA) and a collagen polytetrafluoroethylene (ePTFE) sutures. C: to the crest of the socket. plug contained with 4-0 chromic gut. C: Six- Uncomplicated implantation 4 months postex- week healing. D: Implant placement without traction. D: Healing abutments placed for one- need for further grafting. stage surgery.

Figure 4—A: Occlusal view of FDBA in sock- Figure 5—A: Horizontal mattress suture Figure 6—A: Hopeless tooth No. 8. B: et. B: Placement of collagen plug. C. Occlusal placed. B: Occlusal view of preservation. C: Atraumatic extraction executed. C: Probing view of collagen plug. D: Suturing with 4-O Ridge 3 months postextraction. D: Buccal wall reveals thin buccal plate. D: Vertical incision chromic gut. stays whole at implantation. placed at distal line angle of tooth distal to extraction site. Note termination of the inci- sion is at a 90-degree angle to ease suturing. Tooth No. 8 mesial papilla raised with sulcular extension on buccal to improve visualization.

40 CONTEMPORARY ESTHETICS | FEBRUARY 2007 IMPLANT DENTISTRY

Each figure contains four panels. Starting from the top left and proceeding clockwise, these are designated from A to D.

Figure 7—A: Absorbable collagen membrane Figure 8—A: Three-months healing of tooth Figure 9—A: Tooth No. 8 exhibits fracture. B: placed over grafted socket. B: Suturing with No. 8 site. B: Ridge preserved and filled with Atraumatic extraction performed. C: Collagen 4-O ePTFE material. C: Occlusal view reveals hard tissue. C: Horizontal bulk maintained. D: membrane placed at missing buccal plate collagen plug placed on top of membrane. D: Implant placed without buccal compromise. region. D: Membrane adapted to mimic labial One-week healing. plate with a .

bone-forming cells), and xenografts (animal bone) as well as alloplasts (synthetic bone) are osteoconductive (serve as scaffolds for bone-forming cells). Most studies on socket preser- vation involve allografts and xenografts. Allografts, such as dem- ineralized or mineralized freeze-dried Figure 10—A: Occlusal view of extraction Figure 11—A: Interim removable partial socket with nonintact buccal plate. B: denture for tooth No. 8 in place. B: Occlusal bone allograft (DFDBA and FDBA), Occlusal view of membrane positioning. C: view reveals collagen plug placed over mem- appear to work. Because it contains Placement of FDBA in socket with absorbable brane and secured with 4-O ePTFE sutures. calcium and phosphate salts, FDBA membrane containing it labially. D: Membrane resorbs more slowly than DFDBA, suture over socket with 5-O chromic gut. allowing for better space mainte- nance; a positive attribute for implant allows for soft-tissue growth over because the host bone must grow site development.23 Xenografts resorb itself. If a membrane was used, into the site, replace graft material, very slowly as well. In fact, one inves- ensure that the flap or at least a mature, and remodel. If implant tigation showed graft particles that collagen plug covers it entirely therapy is desired, a minimum lasted 44 months after placement.24 (Figures 7B and 7C). Suture with of 3 months should pass before Despite a potentially greater propor- 4-0 suture material (Figures 4D, implantation. tion of graft material that remains, 5A, 5B, 7B, and 7C). Use gut if no the dental literature does not reflect immediate temporization is antici- Material Options higher implant failure with the use of pated or a nonabsorbable material What materials should be used in xenograft.25 It is best to use either an if there is. socket preservation? There is no con- auto-, allo-, or xenograft for preser- 7. Healing—Recall the patient at 1 to 2 sensus in the dental literature with vation, because strong evidence does weeks, 4 weeks, and 3 months respect to graft types and membrane. not exist for alloplasts. If the restora- postextraction to assess healing. In general, autografts (self bone) are tive plan warrants a longer-lasting Sutures may be removed 7 to 14 osteogenic (possess bone-forming graft, then use FDBA. days after surgery. Healing of bone cells), allografts (non-self human The indication for membrane use grafting takes at least 3 months bone) are osteoinductive (attract is in the case of buccal wall dehiscence

42 CONTEMPORARY ESTHETICS | FEBRUARY 2007 or fenestration (Figures 9 through 11). Preservation of alveolar bone in extraction incidence of painful socket. Br J Oral sockets using bioabsorbable membranes. J Maxillofac Surg. 1988;26(5):402-409. In the former scenario, the most coro- Periodontol. 1998;69(9):1044-1049. 19. Novartis Important Safety Information. nal area of the buccal wall is gone; in 4. Lekovic V, Kenney EB, Weinlaender M, et al. September 2005. Available at: http://- the latter case, the coronal most por- A bone regenerative approach to alveolar www.us.zometa.com/info/patientsafetyinfo.jsp. ridge maintenance following tooth extrac- Accessed August 27, 2006. tion remains intact, but a window of tion. Report of 10 cases. J Periodontol. 20. American Academy of bone is absent apically. The membrane 1997;68(6):563-570. Statement on Bisphosphonates. August 2005. 5. Schropp L, Wenzel A, Kostopoulos L, et al. Available at: http://www.perio.org/resources- acts as the missing buccal wall and Bone healing and soft-tissue contour products/bisphosphonates.htm. Accessed August helps to contain the socket graft changes following single-tooth extraction: a 27, 2006. material. Both nonabsorbable and clinical and radiographic 12-month prospec- 21. Ruggiero SL, Gralow J, Marx RE, et al. tive study. Int J Periodontics Restorative Practical guidelines for the prevention, diag- absorbable membranes can be used Dent. 2003;23(4):313-323. nosis, and treatment of osteonecrosis of the successfully. The advantage of an 6. Atwood DA. Reduction of residual ridges in jaw in patients with cancer. J Oncol Prac. the partially edentulous patient. Dent Clin 2006;2(1):7-14. absorbable membrane is that it does North Am. 1973;17(4):747-754. 22. Spray JR, Black CG, Morris HF, et al. The not require removal and may react 7. Carlsson GE, Ragnarson N, Astrand P. influence of bone thickness on facial margin- Changes in height of the in al bone response: stage 1 placement through better if exposed.26,27 If a buccal wall edentulous segments. A longitudinal clinical stage 2 uncovering. Ann Periodontol. remains intact and has a surfeit and radiographic study of full upper denture 2000;5(1):119-128. of bone, at least 1.0 mm to 2.0 mm, a cases with residual lower anteriors. Odontol 23. Wang HL, Cooke J. Periodontal regeneration Tidskr. 1967;75(3):193-208. techniques for treatment of periodontal diseases. membrane may not be necessary. 8. Tallgren A. The continuing reduction of the Dent Clin North Am. 2005;49(3):637-659, vii. residual alveolar ridges in complete denture 24. Skoglund A, Hising P, Young C. A clinical and wearers: a mixed-longitudinal study covering histologic examination in humans of the Conclusion 25 years. J Prosthet Dent. 1972;27(2):120-132. osseous response to implanted natural bone Socket preservation using bone grafts 9. Cawood JI, Howell RA. A classification of the mineral. Int J Oral Maxillofac Implants. edentulous jaws. Int J Oral Maxillofac Surg. 1997;12(2):194-199. with or without membranes appears to 1988;17(4):232-236. 25. Wallace SS, Froum SJ. Effect of maxillary arrest vertical resorption entirely and 10. Misch CE, Judy KW. Classification of partial- sinus augmentation on the survival of ly edentulous arches for implant dentistry. Int endosseous dental implants. A systematic reduce horizontal loss to roughly 1.0-mm J Oral Implantol. 1987;4(2):7-13. review. Ann Periodontol. 2003;8(1):328-343. to 1.5 mm instead of the 3.0-mm to 6.0- 11. Zarb GA, Zarb FL. Tissue integrated dental 26. Friedmann A, Strietzel FP, Maretzki B, et al. mm reduction seen without interven- prostheses. Quintessence Int. 1985;16(1):39-42. Histological assessment of augmented jaw 12. Araujo MG, Lindhe J. Dimensional ridge bone utilizing a new collagen barrier mem- 2,3,28-30 tion. Interestingly, a few studies alterations following tooth extraction. An brane compared to a standard barrier mem- show a 1.0 mm gain in vertical experimental study in the dog. J Clin brane to protect a granular bone substitute 2,28 Periodontol. 2005;32(2):212-218. material. Clin Oral Implants Res. 2002;- dimension after preservation. 13. Botticelli D, Berglundh T, Lindhe J. Hard-tis- 13(6):587-594. Gentle manipulation of tissue is the sue alterations following immediate implant 27. Moses O, Pitaru S, Artzi Z, et al. Healing of key. Maintenance of the bony archi- placement in extraction sites. J Clin dehiscence-type defects in implants placed Periodontol. 2004;31(10):820-828. together with different barrier membranes: a tecture allows the practitioner to 14. Nevins ML, Karimbux NY, Weber HP, et al. comparative clinical study. Clin Oral Implants fashion the most natural and stable Wound healing around endosseous implants Res. 2005;16(2):210-219. in experimental diabetes. Int J Oral 28. Vance GS, Greenwell H, Miller RL, et al. restoration possible, which is some- Maxillofac Implants. 1998;13(5):620-629. Comparison of an allograft in an experimen- thing the patient will appreciate. 15. Labriola A, Needleman I, Moles DR. tal putty carrier and a bovine-derived Systematic review of the effect of smoking on xenograft used in ridge preservation: a clini- nonsurgical periodontal therapy. Periodontol cal and histologic study in humans. Int J Oral References 2000. 2005;37:124-137. Maxillofac Implants. 2004;19(4):491-497. 1. Camargo PM, Lekovic V, Weinlaender M, et 16. Trombelli L, Cho KS, Kim CK, et al. Impaired 29. Vasilic N, Henderson R, Jorgenson T, et al. The al. Influence of bioactive glass on changes in healing response of periodontal furcation use of bovine porous bone mineral in combina- alveolar process dimensions after exodontia. defects following flap surgery in tion with collagen membrane or autologous Oral Surg Oral Med Oral Pathol Oral Radiol smokers. A controlled clinical trial. J Clin fibrinogen/fibronectin system for ridge preser- Endod. 2000;90(5):581-586. Periodontol. 2003;30(1):81-87. vation following tooth extraction. J Okla Dent 2. Iasella JM, Greenwell H, Miller RL, et al. 17. Larsen PE. Alveolar osteitis after surgical Assoc. 2003;93(4):33-38. Ridge preservation with freeze-dried bone removal of impacted mandibular third molars. 30. Zubillaga G, Von Hagen S, Simon BI, et al. allograft and a collagen membrane compared Identification of the patient at risk. Oral Surg Changes in alveolar bone height and width fol- to extraction alone for implant site develop- Oral Med Oral Pathol. 1992;73(4):393-397. lowing post-extraction ridge augmentation ment: a clinical and histologic study in 18. Meechan JG, Macgregor ID, Rogers SN, et using a fixed bioabsorbable membrane and humans. J Periodontol. 2003;74(7):990-999. al. The effect of smoking on immediate post- demineralized freeze-dried bone osteoinduc- 3. Lekovic V, Camargo PM, Klokkevold PR, et al. extraction socket filling with blood and on the tive graft. J Periodontol. 2003;74(7):965-975.

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