Practical small animal periodontology (Proceedings)

The largest portion of our dentistry case load in everyday practice involves the treatment of periodontal disease. No other oral malady will present itself more commonly. At the same time proper evaluation of the stage of periodontal disease is determined with probing, visual examination and radiographically. This lecture will take a look at several examples of cases that are commonly encountered in veterinary practice and take you through the steps required to resolve these cases therapeutically. Infrabony pocket repair is one of the most challenging aspects of periodontal care. The discussion below is an adjunct to the case format lecture and is provided for future reference.

The goal and rationale in approaching surgical therapy for infrabony pockets is to create the ideal environment for new attachment of periodontal ligament fibers to new cementum and for gingival epithelium to adhere to tooth structure. This process starts with the provision of adequate visualization with the aid of a mucoperiosteal flap. This allows the operator to thoroughly clean diseased tissue from the defect and the gingiva through root planning and subginvial curettage. Once completed, a variety of products may be used to enhance the healing effort to create new attachment.

Several compounds are currently in use to biomodify the root surface to enhance new attachment. Discussion of all such compounds is beyond the scope of this paper, however citric acid and 24% EDTA are two common compounds traditionally used for root surface treatments. Both act to demineralize the root surface in an attempt to expose collagen fibers creating an ideal surface for population with periodontal ligament cells. It has been shown that treatments with both agents attract fibroblasts that act with other cells to initiate the process of collagen synthesis which is the structural component of periodontal ligament fibers. 24% EDTA was chosen in this case for several reasons. Although effective at demineralizing the root surface citric acid has a necrotizing effect on the surrounding tissues due to its low ph. 24% EDTA operates at a neutral ph and promotes the healing of periodontal tissue. Materials used for grafting in infrabony defects are also classified regarding their ability to be osteogenic, osteoinductive or osteoconductive. Osteogenic compounds have cells capable of synthesizing new bone within the compound itself. The most common example of an osteogenic graft material is cancellous bone grafts from the patient. The added anesthesia time and technical difficulty involved with obtaining this material makes it a less viable choice despite the desirability of its osteogenic nature. Osteoinductive materials contain cells that promote patient cell transformation to osteoblasts. One such material is decalcified freeze-dried bone allograft (DFDBA) which contains bone morphogenic protein. Although an excellent alternative to autogenous bone grafts cost is a major deterrent with this material. Osteoconductive compounds act as a matrix for migration of cells that aid in the production of new bone. Examples include hydroxyapatite, tricalcium phosphate and bioactive glass. Bioactive glass was the compound used in this case for several reasons. It is approved for veterinary use as a grafting material to treat infrabony defects. It has been shown to be effective in treating infrabony defects in humans and in the dog and cat.

It is capable of impeding the downgrowth of epithelial tissues that prevent new attachment of the periodontal ligament and has proven superior to hydroxyapaitie and tricalium phosphate in its ablility to do so. It has also been shown to have an antibacterial effect against oral microbes in vitro.

Consideration was given to the use of a membrane to aid exclusion of unwanted tissue migration into the pocket during healing. Research involving Class II furcations in humans has shown no benefit when using a membrane over that of bioiactive glass. The favorable long term outcome described in this case report supports the use of bioactive glass and 24% EDTA in the manner described to treat infrabony defects in dogs.

References

Carranza FA Rationale for Periodontal Treatment In: Clincial Periodontolgy, 9th Edition, Saunders, Philadelphia, WB Saunders 507-511 (2002)

Bergenholtz A, Babay N Scanning electron microscopy of the root surface texture of extracted periodontally diseased teeth following various etching and chelating regimens. Int J Periodontics Restorative Dent 1998 Apr;18(2):171-9

Babay N Attachment of human gingival fibroblasts to periodontally involved root surface following scaling and/or etching procedures: a scanning electron microscopy study. Braz Dent J 2001;12(1):17-21

Carranza FA Tooth Supporting Structures In: Clincial Periodontolgy, 9th Edition,Saunders, Philadelphia, WB Saunders 35-42 (2002)

Blomlof JP, Blomlof LB, Lindskog SF Smear removal and collagen exposure after non- surgical root planing followed by etching with an EDTA gel preparation. J Periodontol 1996 Sep;67(9):841-5

Blomlof J, Jansson L, Blomlof L, Lindskog S Root surface etching at neutral pH promotes periodontal healing. J Clin Periodontol 1996 Jan;23(1):50-5

Carranza FA et al Regenerative Osseous Surgery In: Clincial Periodontolgy, 9th Edition Saunders, Philadelphia, WB Saunders 809-820 (2002)

Wiggs RB, Lobprise HB. Periodontology. In: Wiggs RB, Lobprise HB VeterinaryDentistry Principles and Practice. Philadelphia, Lippincott, 222 (1997)

Deforge DH, Evaluation of Bioglass/Perioglass (Consil) synthetic bone graft particulate in the dog and cat. J Vet Dent 1997 Dec;(14):4

Han J, Meng H, Xu L Clinical evaluation of bioactive glass in the treatment of periodontal intrabony defects Zhonghua Kou Qiang Yi Xue Za Zhi 2002 May;37(3):225-7

Park JS, Suh JJ, Choi SH, Moon IS, Cho KS, Kim CK, Chai JK Effects of pretreatment clinical parameters on bioactive glass implantation in intrabony periodontal defects. J Periodontol 2001 Jun;72(6):730-40

Karatzas S, Zavras A, Greenspan D, Amar S Histologic observations of periodontal wound healing after treatment with PerioGlas in nonhuman primates. Int J Periodontics Restorative Dent 1999 Oct;19(5):489-99

Allan I, Newman H, Wilson M Particulate Bioglass reduces the viability of bacterial biofilms formed on its surface in an in vitro model. Clin Oral Implants Res 2002 Feb;13(1):53-8

Stoor P, Soderling E, Salonen JI Antibacterial effects of a bioactive glass paste on oral microorganisms. Acta Odontol Scand 1998 Jun;56(3):161-5

Yukna RA, Evans GH, Aichelmann-Reidy MB, Mayer ET Clinical comparison of bioactive glass bone replacement graft material and expanded polytetrafluoroethylene barrier membrane in treating human mandibular molar class II furcations. J Periodontol 2001, Feb;72(2):125-33