Evaluation of Recession Defects Treated With Coronally Advanced Flaps and Either Recombinant Human Platelet-Derived Growth Factor-BB Plus ?-Tricalcium Phosphate or Connective Tissue: Comparison of Clinical Parameters at 5 Years

• Autores: Michael K. McGuire, E. Todd Scheyer, Mark B. Snyder
• Localización: Journal of periodontology, ISSN 0022-3492, Nº. 10, 2014, págs. 1361-1370
• Idioma: inglés
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• Resumen

  • Background: In a previously reported split-mouth, randomized controlled trial, Miller Class II gingival recession defects were treated with either a connective tissue graft (CTG) (control) or recombinant human platelet-derived growth factor-BB + ?-tricalcium phosphate (test), both in combination with a coronally advanced flap (CAF). At 6 months, multiple outcome measures were examined. The purpose of the current study is to examine the major efficacy parameters at 5 years.

    Methods: Twenty of the original 30 patients were available for follow-up 5 years after the original surgery. Outcomes examined were recession depth, probing depth, clinical attachment level (CAL), height of keratinized tissue (wKT), and percentage of root coverage. Within- and across-treatment group results at 6 months and 5 years were compared with original baseline values.

    Results: At 5 years, all quantitative parameters for both treatment protocols showed statistically significant improvements over baseline. The primary outcome parameter, change in recession depth at 5 years, demonstrated statistically significant improvements in recession over baseline, although intergroup comparisons favored the control group at both 6 months and 5 years. At 5 years, intergroup comparisons also favored the test group for percentage root coverage and change in wKT, whereas no statistically significant intergroup differences were seen for 100% root coverage and changes to CAL.

    Conclusions: In the present 5-year investigation, treatment with either test or control treatments for Miller Class II recession defects appear to lead to stable, clinically effective results, although CTG + CAF resulted in greater reductions in recession, greater percentage of root coverage, and increased wKT.

    Achieving successful long-term clinical outcomes is the primary goal in treating the functional and esthetic problems resulting from gingival recession (GR). These clinical problems (e.g., chronic dentinal sensitivity, esthetic deficiencies, poor plaque control) require effective surgical interventions that result in minimal short- and long-term sequelae. A number of systematic reviews have examined a range of therapeutic approaches to recession defects, including the coronally advanced flap (CAF) alone, CAF in combination with the subepithelial connective tissue graft (CTG), guided tissue regeneration (GTR), acellular dermal matrix (ADM), and enamel matrix derivative (EMD).1-12 When examining specific clinical parameters, alternative protocols to CAF + CTG often appear quite effective. However, most current reviews suggest that only CAF + CTG appears to be consistently effective across all measured outcome parameters, especially root coverage stability over time.1,2,4-9,11-15 CAF + CTG, although often considered the gold standard for root coverage treatment, has a number of disadvantages: 1) an additional surgery to obtain donor tissue is needed; 2) increased morbidity may result from the harvesting procedure; and 3) a finite amount of autogenous donor tissue is available, restricting the number of possible treated sites per patient visit.16,17 In addition, evidence suggests that CAF + CTG has limited ability to regenerate missing tissues of the attachment apparatus when treating recession defects. Instead, most studies support healing through either connective tissue adaptation with adjacent root surfaces or a long junctional epithelium.17-22 As a result of these disadvantages, along with limited ability to effect true periodontal regeneration, alternatives to CAF +CTG continue to be sought.14,23-33 Recent advances in recombinant growth factor technology may offer viable alternatives to CTG, including the potential to regenerate missing cementum, periodontal ligament, and supporting alveolar bone.

    In a published study, McGuire et al.34 examined growth factor�mediated clinical and histologic results for the treatment of human Miller Class II recession defects treated with a composite graft of recombinant human platelet-derived growth factor-BB (rhPDGF-BB) and ?-tricalcium phosphate (?-TCP) in conjunction with CAF. In the randomized controlled trial (RCT) portion of the study, 30 patients with contralateral recession defects ?3 mm deep and ?3 mm wide were treated with either CTG (control) or 0.3 mg/mL rhPDGF-BB + ?-TCP + an absorbable collagen wound healing dressing (test), each in combination with CAF. At the end of 6 months, both the test and control treatments demonstrated significant improvements from baseline. Statistically significant results favoring CTG included recession depth reduction, percent root coverage, and recession width reduction, whereas mid-buccal probing depth reduction (PDR) favored the growth factor�mediated treatment. There were no statistically significant differences detected between test and control groups for height of keratinized tissue (wKT), patient satisfaction, and esthetic results. According to the authors, at 6-month follow-up, both test and control treatments appeared to be viable alternative treatments for Miller Class II recession defects.34,35 Although 6-month follow-up durations yield valuable outcome information, longer-term data validating stable recession treatment clinical results over time are desirable. Systematic reviews of GR RCTs require at least a 6-month post-surgery follow-up and often extend an additional 6 months.2,3,6,8-12 Occasionally, longer RCT follow-up times extending to 2 years post-grafting are included in systematic reviews of GR treatment. Apart from systematic reviews, a number of individually reported studies examining a variety of treatment protocols extend GR treatment follow-up times from 4 to 14 years, reporting a wide range in stability of outcome measures initially reported at 6 to 12 months.36-40 The purpose of the current study is to examine the major patient-centered and clinical quantitative parameters initially reported by McGuire et al. in 2009,34 ?5 years after original treatment with either CTG or rhPDGF-BB + ?-TCP + an absorbable collagen wound healing dressing, each in conjunction with CAF.