Periodontal Disease: Part IV
Treatment Strategies Cont. (Surgical Removal of Diseased Tissue)
Geneviève Bussac, DDS, DUICP
Surgical Removal of Diseased Tissue
Periodontal surgery was formerly perceived as an excisional process. Although the objective of such therapy--the elimination of periodontal pockets--was accomplished, generations of patients experienced postoperative sensitivity and aesthetically compromised teeth. In reality, periodontal surgery is reconstructive and regenerative in nature, and recent surgical innovations have improved the success and predictability of aesthetic treatment. Gingival recession defects can be treated with a variety of periodontal plastic surgical techniques such as laterally or coronally positioned flaps, free gingival grafts, subepithelial connective tissue grafts, and guided tissue regeneration (GTR) procedures. The preparation of the affected tooth root is required in the initial therapeutic phase. Once root planing has been completed, demineralization is performed with citric acid to establish a joint at the cementoenamel junction and enhance connective tissue attachment of the selected graft to the root surface.
When the lateral slide technique was first introduced by Grupe and Warren, it was the only surgical procedure that could predictably achieve root coverage in marginal tissue recession. This procedure can be effective in many instances, although it cannot be performed on multiple recessions, gingival tissue of insufficient dimension, or when the interdental bone and tissues have been lost. The lateral sliding technique is indicated for single-site recession, and can provide aesthetic results without the need to involve a second surgical site as a donor. Coronally positioned flaps can be utilized for the treatment of single-tooth recession associated with multiple adjacent tooth recession. In order to be successful, this modality requires the presence of a minimum (3 mm) of keratinized tissue, adequate thickness of the keratinized apical gingiva, and a sufficient vestibular tissue depth to permit flap mobilization. In addition, no loss of interdental soft tissue or bone can be present. The subepithelial connective tissue graft was originally described by Langer et al, and may be an alternate method of performing periodontal surgery.1 This technique can provide increased blood supply to the graft through an overlying flap, and is indicated for single and multiple recessions with aesthetic considerations. Ultimately, the restoration of lost interdental papilla between anterior dentition represents a significant aesthetic challenge for the clinician - this condition has been addressed with limited success using surgical and nonsurgical means.2
The use of an acellular, biocompatible connective tissue matrix has been proposed to treat soft tissue defects; this procedure attempts to avoid the use of a tissue donor site and potential complications that arise from anatomical variation among patients. The dermal matrix is an allograft of human skin that has been freeze-dried following the elimination of its epithelium and all cellular components. The matrix is generally combined with a coronally positioned pedicle flap procedure. Once the flap surgery has been performed, a dose of doxycycline is administered locally. Postoperative evaluation of the sites treated with a connective tissue graft and the acellular dermal matrix have exhibited similar results. These conclusions were similar to those of researchers who analyzed the clinical effectiveness of a connective tissue graft (including periosteum used as a barrier) for GTR in interproximal bony defects.3,4
Since bone and gingival loss from advanced periodontal disease compromise the prognosis of the teeth, numerous procedures have attempted to use mucogingival surgery to achieve root coverage and cicatrization with neoattachment. The objective of GTR is the selective repopulation of a diseased root surface with cells from the periodontal ligament through the use of a barrier membrane. The placement of a cell-occlusive physical barrier between the connective tissue and the alveolar bone defect prevents the collapse of the soft tissue, selective reparation from the desmodontal and bone cells while excluding the gingival cells and creates a space where blood can clot and provide a blood supply for bone formation. The histological analysis of regenerated periodontal tissue demonstrates new bone with numerous osteocytes.
Nonresorbable barrier membranes composed of expanded polytetrafluoroethylene have also been successfully utilized for guided bone regeneration. Since a second surgical stage is required to facilitate barrier removal, considerable research has been directed toward the development of a suitable resorbable alternative that can eliminate this second surgery. Contemporary bioresorbable materials are composed of copolymer lactide and glycolyde, vicryl, and collagen (Figure 1). Every barrier must satisfy criteria for biocompatibility, cell exclusivity, tissue integration, spacemaking, and clinical manageability, or it risks the failure of the GTR procedure.
Numerous studies have verified that the membrane can be contaminated by infections generated during GTR procedures. Since surgical complications and wound infections can reduce the clinical attachment, these difficulties should be avoided in order to ensure the success of the periodontal therapy. The premature exposure and absence of oral hygiene is followed by the fixation of the bacteria on the surface of the membrane. One recent study compared the in vivo bacterial colonization of three different methods of tissue regeneration and noted that plaque accumulation on the membranes appeared to be related to the textural and structural characteristics of the surface.5 Consequently, selection of the appropriate periodontal technique is critical to the oral health of the patient.
For more that a decade, considerable effort has been spent on the development of materials and bioactive molecules (eg, growth and differentiation factors) capable of regenerating lost bone.6 Large defects may require the use of bone grafts and guided bone regeneration to facilitate periodontal regenerative therapy. The graft material supports the membrane and prevents its collapse into the space required for bone regeneration. The graft also induces new bone growth through osteoconduction, osteoinduction, or a combination of these principles. The literature describes multiple bone grafting procedures that have been used in periodontal therapy, including the use of autogenous grafts with conductive and inductive properties. Although these procedures can be successful, the risks to the patient are compounded by the need for a donor site. Accordingly, allografts (ie, demineralized freeze-dried bone) xenografts, and alloplastic grafts (eg, bioceramics, bioactive glass synthetic ceramics, polymethacrylates) have all been developed as alternatives to the use of autogenous bone. These materials have varying osteoconductive properties and should be free of pathogens and infective agents.
The Dual Approach to Therapy
In order to provide a more effective means of treating periodontal disease, contemporary research has investigated the direct cause of tissue breakdown - the host response and its related matrix metalloproteins. It is anticipated that the modulation of the host response with a dual approach will reduce the tissue breakdown.
One component of this approach involves tetracycline, which has long been used as an adjunct to periodontal therapy due to its antimicrobial properties. Tetracycline solutions are effective against gram-negative bacteria, and demonstrate a tendency to concentrate in the crevicular fluid in a manner that prolongs the antimicrobial therapeutic activity. Research has demonstrated the presence of an independent mechanism in tetracycline that provides additional therapeutic benefits.7 The mechanism is able to initiate fibroblast and connective tissue attachment that promotes the regeneration of lost periodontal tissues; it also develops anti-inflammatory properties in the treatment of specific manifestations of periodontal disease. Tetracycline also exhibits unique anticollagenase activity that inhibits the connective tissue degradation and bone resorption characteristic of the periodontal disease process.
Golub et al also confirmed the role of osteoblast collagenase in the process of bone resorption and determined that the combination of nonsteroidal anti-inflammatory drugs (NSAIDs) with tetracycline can synergistically reduce tissue breakdown in periodontitis. As a result of tetracycline's ability to modulate various host responses through the inhibition of metalloproteinase and its ability to enhance collagen and bone formation, the researchers formulated a low-dose (20 mg) doxycycline (LDD) capsule. According to preliminary study,8 this regimen could significantly inhibit mammalian collagenase activity in the gingival tissue and crevicular fluid; it was also able to prevent the progression of periodontal disease without producing typical antibiotic side effects.
Upon consideration of these studies, it is apparent that LLD has several important effects on periodontal disease. In addition to the inhibition of collagenase and gelatinase, matrix metalloproteins are not able to inactivate the serum protein and the X1 proteinase inhibitor. The LLD also inhibits the degradation of noncollagenase matrix constituents (eg, elastic fibers, fibronectin, proteoglycans). In addition to this anticollagenase property, doxycycline is known to inhibit connective tissue destruction during periodontal disease by preventing the production of reactive oxygen metabolites from bone and leukocyte cells. Although LDD does not affect the plaque index and severity of gingival inflammation, it reduces the severity of breakdown and improves the probing depth and attachment loss. This apparent dissociation between inflammatory and tissue destruction indices has previously been explained by Greenwald et al.9 Low-dose doxycycline has been developed to facilitate enzymatic action without a concurrent tetracycline-resistance or side effects.
The second aspect of the dual approach to periodontal therapy requires the utilization of NSAIDs, which have been demonstrated to prevent or reduce the production of the mediators that can cause alveolar bone resorption through the modification of the host immunoinflammatory response. The efficacy of systemic use of an antibiotic (doxycycline) and an NSAID (ibuprofen) used separately or in combination was evaluated as an adjunctive treatment to scaling and root planing for adult periodontitis.10 The results of this combined therapy indicated significant clinical improvement in the achievement of an overall gain of clinical attachment and the reduction of gingival inflammation and probing depth.
According to recent epidemiological surveys, millions of patients are affected by periodontal diseases. Since risk factors have demonstrated a direct relationship with the manifestation of periodontal diseases, these factors must be carefully evaluated prior to the initiation of periodontal treatment. Periodontal infections are themselves a high risk factor for other diseases (eg, heart disease), and clinicians have a responsibility to encourage patients to improve their oral health to avoid negative effects intraorally or in the body. It is critical, therefore, to disseminate this information to patients. The extensive experience we have with varying methods of rendering periodontal treatment allows the optimal solution to be adapted to each complex presentation of disease. When this scientific support and clinical experience is applied in concert with a team approach, the patient is the ultimate beneficiary of improved health care.
- Langer B, Calagna L. The subepithelial connective tissue graft. J Prosthet Dent 1980;44(4):363-367.
- Nordland WP, Tarnow DP. A classification system for loss of papillary height. J Periodontal 1998;69:1124-1126.
- Kwan SK, Lekovic V, Camargo PM, et al. The use of autogenous periosteal grafts as barriers for the treatment of intrabony defects in humans. J Periodontol 1998;69(11):1203-1209.
- Trombelli L, Tatakis DN, Scabbia A, Zimmerman GJ. Comparison of mucogingival changes following treatment with coronally positioned flap and guided tissue regeneraion procedures. Int J Periodont Rest Dent 1997;17(5):449-455.
- De Sanctis M, Zucchelli G, Clauser C. Bacterial colonization of bioabsorbable barrier material and periodontal regeneration. J Periodontol 1996;67(11):1193-1200.
- Giannobile WV, Ryan S, Shih MS, et al. Recombinant human osteogenic protein-1(OP-1) stimulates periodontal wound healing in Class III furcation defects. J Periodontol 1998;69(2):129-137.
- Golub LM, Ramamurthy NS, McNamara TF, et al. Tetracyclines inhibit connective tissue breakdown: New therapeutic implications for an old family of drugs. Crit Rev Oral Biol Med 1991;2(3):297-321.
- Crout RJ, Lee HM, Schroeder K, et al. The "cyclic" regimen of low-dose doxycycline for adult periodontitis: A preliminary study. J Periodontol 1996;67(5):506-514.
- Greenwald RA, Moak SA, Golub LM. Low dose doxycycline inhibits pyridinoline excretion in selected patients with rheumotoid arthritis. Ann NY Acad Sci 1994;732:419-421.
- Ng VW, Bissada NF. Clinical evaluation of systemic doxycycline and ibuprofen administration as an adjunctive treatment for adult periodontitis. J Periodontol 1998;69(7):772-776.