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

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.

After bilateral extraction of the mandibular second and third premolars and a 3-month healing period, 30 SLActive(®) 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).

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).

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.