Healing of peri-implant tissues after flapless and flapped implant installation

Aim: The aim of this study was to investigate the consequences of different flapless procedures for the installation of dental implants on peri-implant bone response. Materials and methods: After bilateral extraction of the mandibular second and third premolars and a 3-month healing period, 30 SLActive (R) implants were installed for 3 months in 10 Beagle dogs according to three different surgical approaches, i.e.: (1) flapped (F), (2) tissue punch flapless (P), and (3) direct flapless (DF). Results: At harvesting, 29 implants were analysed. Micro-computed tomography and histomorphometrical evaluation (which also included the mobile implants) showed comparable results in bone volume (F = 55 +/- 9, P = 51 +/- 4, DF = 54 +/- 5) and crestal bone level (F = 3420 +/- 762, P = 5358 +/- 1681, DF = 3843 +/- 433). However, the implants inserted using the punch approach revealed a significantly lower first bone contact (F = 3420 +/- 762, P = 5358 +/- 1681, DF = 3843 +/- 433) and bone-to-implant contact percentage (F = 70 +/- 12, P = 48 +/- 23, DF = 73 +/- 12). Considering the gingival response, the barrier epithelium was also significantly deeper around the implants installed using the punch approach (F = 1383 +/- 332, P = 2278 +/- 1154, DF = 1107 +/- 300). Conclusions: The results indicate that a flapless surgical technique can be used for the installation of oral implants. In addition, using a tissue punch wider than the implant diameter should be avoided, as it can jeopardize the outcome of the implantation procedure.