Histopathological comparative analysis of periimplant bone inflammatory response after dental implant insertion using flap and flapless surgical technique. An experimental study in pigs

AimTo evaluate by histopathological analysis the peri-implant bone inflammation degree, in certain time intervals (7, 14, 21 and 28days), following mini-incision flapless and flap implant placement. Material and methodsThe experiment was conducted on four domestic pigs. Nine weeks prior to implant insertion, second and third mandibular premolars were extracted. Each animal received six implants in lower jaw. On one randomly chosen side of jaw flapless technique using mini-incision was performed, while on the other side implants were inserted after flap raising. After 7, 14, 21, and 28days, the experimental animals were sacrificed. Following mandibular resection and decalcification, the samples for histopathological analysis of the peri-implant bone were obtained in the empty implant bed area, from the buccal side of the mandible, adjacent to implant neck region and parallel to crestal edge of implant bed. The degree of inflammatory response of the peri-implant bone was estimated through ordinal scores from 0 to 2. ResultsSeven days after the surgery all samples in the flap group had score 2 indicating high inflammation degree, in contrast to lower inflammatory reaction in flapless group. On the 14th and 21st postoperative day decreasing of inflammation degree was noted in all samples of the flapless group (score 1), while in flap group samples presented scores 1 and 2. Twenty-eight days after the implant placement, further reduction of inflammation in the flapless group (33% of samples had score 0) was observed. ConclusionFlapless technique in comparison to conventional flap procedure minimizes postoperative bone inflammatory reactions.