Submerged flapless technique vs. conventional flap approach for implant placement: experimental domestic pig study with 12-month follow-up

Abstract

OBJECTIVES: The aim of our study was to compare osseointegration and peri-implant crestal bone resorption in submerged flapless and conventional flap surgery over a 12-month follow-up. MATERIALS AND METHODS: The study used five domestic pigs. Implants were inserted 9 weeks after tooth extraction. Each animal received six implants in the mandible, following a split-mouth design: one side was treated using a flapless technique using mini-incisions, while a flap was raised on the other. The animals were sacrificed at 2 weeks, 1, 3, 6 and 12 months after implant placement. Radiographic images were taken to analyze crestal bone loss, and samples were extracted for histopathological and bone-to-implant contact (BIC) analyses. RESULTS: Significantly, greater crestal bone loss (P = 0.005) was obtained in the flap group compared with the flapless group. The flapless group presented significantly higher percentages of BIC (P < 0.05) at 3, 6 and 12 months compared with the conventional flap group. CONCLUSIONS: Within the limitations of this experimental animal study, it may be concluded that the type of surgery (flap or flapless) affects peri-implant bone preservation and osseointegration of regular platform implants. Flapless surgery is associated with peri-implant crestal bone preservation. Flapless surgery in combination with submerged implants allows higher osseointegration values.