Comparison of soft tissue healing around implants in beagle dogs: flap surgery versus flapless surgery

Objective. The objective of this study was to compare soft tissue healing after implant placement in flap and flapless surgery in the dog model. Study Design. Mandibular premolars were extracted from 10 beagle dogs. The extraction sockets were allowed to heal for 8 weeks. After healing, 3 implants on each side of the mandible were implanted using either flap or flapless techniques. One implant was installed on each side at the 0-, 4-, and 6-week time point. Eight weeks later, the peri-implant soft tissue healing was subjected to clinical and immunohistochemical analysis. Results. It was revealed that vascular endothelial growth factor (VEGF) expression, peri-implant crevicular fluid (PICF) volume, and the aspartate aminotransferase and alkaline phosphatase activity in PICF increased significantly in the 2-week flap group compared with the 2-week flapless group. Microvascular density and VEGF expression in the 8-week flap group was statistically significantly lower than the 8-week flapless group and normal group. Buccal gingival recession was less pronounced in the flapless group than in the flap group after 4 and 8 weeks. Conclusions. Within the limits of this study, the results demonstrate that flapless surgery contributes to better esthetic outcomes in implants compared with the flap approach. (Oral Surg Oral Med Oral Pathol Oral Radiol 2013;115:e21-e27)