Comparison of two types of xenogeneic matrices to treat single gingival recessions: A randomized clinical trial.

BACKGROUND: Xenogeneic matrices (XMs) have been increasingly used for root coverage procedures. This study compared the use of two types of XM (collagen matrix [CM] and xenogeneic acellular dermal matrix [XDM]) associated with the coronally advanced flap technique (CAF) to treat single gingival recessions. METHODS: Seventy-five patients presenting single RT1 gingival recession were treated by CAF (control group, n = 25), CAF+CM (test group 1, n = 25), or CAF+XDM (test group 2, n = 25) and completed 6-month follow-up. Clinical, patient-centered, and esthetic assessments were performed and intra- and intergroup differences were analyzed. RESULTS: At 6 months, the mean recession reduction for CAF, CAF+CM, and CAF+XDM was 2.4 ± 0.8 mm, 2.4 ± 0.9 mm and 2.1 ± 0.8 mm, respectively (P > 0.05). The corresponding mean percentage of root coverage was 78.9% ± 26.2% for CAF, 78.0% ± 28.5% for CAF+CM, and 65.6% ± 26.9% for CAF+XDM (P > 0.05). Dentin hypersensitivity and esthetic conditions showed significantly improvements in all groups. Test groups presented significant gains in gingival thickness (GT; CAF+CM: 0.4 ± 0.3 mm; CAF+XDM: 0.4 ± 0.2 mm) compared to the control group (CAF: 0.0 ± 0.1 mm; P < 0.05). CONCLUSION: The CAF, CAF+CM, and CAF+XDM treatments each provided similar results in the treatment of single gingival recessions. The addition of either CM or XDM to CAF increases the GT.

Effects of Nd:YAG laser irradiation on root canal dentin wall: a scanning electron microscopic study.

OBJECTIVE: The purpose of this study was to evaluate, by scanning electron microscopy (SEM), the effects of Nd:YAG laser irradiation applied perpendicular or parallel to the root canal dentin wall. METHODS: Thirty human teeth were divided into two groups: Group A (20 roots), laser application with circular movements, parallel to the dentin root surface; and Group B (10 roots), roots cut longitudinally and laser applied perpendicular to the root surface. Group A was subdivided into A1 (10 roots), laser application with 100 mJ, 15 Hz and 1.5 W; and A2 (10 roots) with 160 mJ, 15 Hz, and 2.4 W. Group B was subdivided into B1 (10 hemisections) and B2 (10 hemi-sections) with parameters similar to A1 and A2. Four applications of 7-sec duration were performed, with a total exposure of 28 sec. SEM evaluations were made in the cervical, middle, and apical thirds, with 500x and 2000x magnifications. Morphological changes scores were attributed, and the results were submitted to Kruskal Wallis statistical test (5%). RESULTS: Significant statistical differences were found between groups Aand B (p = 0.001). In groups A1 and A2, few areas of dentin melting were observed. In groups B1 and B2, areas of melting dentin covering dentin surface were observed. CONCLUSIONS: It was concluded that intracanal laser application with circular movements (parallel to the surface) produces limited morphological changes in root canal dentin wall.