Efficacy of Acellular Dermal Matrix and Coronally Advanced Flaps for the Treatment of Induced Gingival Recession Defects: A Histomorphometric Study in Dogs Khalid Al-Hezaimi,* † Ivan Rudek, ‡ Khalid Saleh Al-Hamdan,* † Fawad Javed,* Giovanna Iezzi, § Adriano Piattelli, § and Hom-Lay Wang i Background: Gingival recession (GR) defects can be treated by various methods, including acellular dermal ma- trix (ADM) or coronally advanced flaps (CAFs). The aim of this histomorphometric experiment is to compare the effi- cacy of ADM and CAF for treating GR defects in dogs. Methods: In eight beagle dogs, a critical-size labial GR de- fect was surgically induced on bilateral maxillary cuspids un- der general anesthesia. Test sites received ADM and CAF, and control sites underwent CAF treatment alone. Plaque in- dex (PI), bleeding index (BI), and gingival index (GI) were measured at 4 weeks (baseline), 8 weeks, and 16 weeks. Width of keratinized gingiva (KG) was determined at baseline and at 16 weeks. Depth of recession and width of GR below the cemento-enamel junction (CEJ) was also determined. After 4 months, animals were sacrificed, and jaw blocks were his- tomorphometrically assessed for tissue thickness and distance from the stent to the gingival margin (GM) and to the CEJ. Results: At 4-, 8-, and 16-week intervals, there was no significant difference in the BI, GI, and PI at the test and con- trol sites. At 16 weeks, thickness of KG was significantly higher at the control sites than test sites (P <0.01). There was no difference in the midfacial recession depth and reces- sion width at the test and control sites at baseline and before euthanasia (16 weeks). Histomorphometrically, there was no significant difference in tissue thicknesses and distances from the stent to the GM and CEJ in the test and control sites. Conclusion: ADM might yield similar results to a CAF alone and could decrease the amount of KG. J Periodontol 2013;84:1172-1179. KEY WORDS Acellular dermal matrix; connective tissue; gingival recession; periodontal diseases; surgical flaps; tissues. V arious treatment strategies have been proposed for the treat- ment of gingival recession (GR) defects. 1,2 One of the earliest tech- niques used for root coverage was the thin free gingival graft (FGG) tech- nique. 3-5 The thin FGG was later mod- ified as the thick FGG; however, the efficacy for root coverage remained dubious. 6,7 Although this technique showed acceptable outcomes in shal- low recession defects, the overall pro- cedure was a failure. 6,7 Nearly three decades ago, the connective tissue graft (CTG) was introduced for ridge augmentation and then for root cover- age. 8,9 Using CTG, successful GR de- fect coverage may be achieved with less donor tissue because re- vascularization occurs from both the periosteal or osseous base and the overlying flap. 7,8 Coronally advanced flaps (CAFs) and their modifications have also been used for treating re- cession defects. 10-12 Compared to other root coverage procedures, CAFs provide a better contour and color match to the site and do not require a donor site. 10 However, lack of height and thickness of gingiva apical to the recession may limit the use of CAFs. Simultaneously, GR treated with * Eng. AB Research Chair for Growth Factors and Bone Regeneration, 3D Imaging and Biomechanical Laboratory, College of Dentistry and College of Applied Medical Sciences, King Saud University, Riyadh, Saudi Arabia. † Department of Periodontics and Community Dentistry, College of Dentistry, King Saud University. ‡ School of Dentistry, University of Michigan, Ann Arbor, MI. § Department of Medical, Oral and Biotechnological Sciences, University of Chieti-Pescara, Chieti-Pescara, Italy. i Department of Periodontics and Oral Medicine, School of Dentistry, University of Michigan. doi: 10.1902/jop.2012.120380 Volume 84 • Number 8 1172