Influence of untreated periodontitis on osseointegration of dental implants in a beagle dog model

Abstract

Background: There have been previous studies on the relationship between periodontitis and periimplantitis, but limited information is available on how periodontitis affects osseointegration and wound healing of newly placed dental implants adjacent to natural teeth. The objective of the present experiment was to evaluate healing around dental implants adjacent to teeth with untreated experimental periodontitis.

Methods: The experiment included 6 male beagle dogs. Scaling and plaque control procedures were performed in 3 dogs (the control group). In the other 3 dogs (the experimental group), retraction cords and ligature wires were placed subgingivally around all premolars and the first molars. Induced experimental periodontitis was confirmed after 3 months. Each control or experimental group was divided into 2 subgroups depending on the timing of implant placement (immediate/delayed). Twelve dental implants (2 implants for each dog) were placed immediately and the other 12 dental implants (2 implants for each dog) were placed two months after extraction. The animals were sacrificed 2 months after implant placement. Histological and histometric analysis were performed.

Results: Four implants (3 from immediate and 1 from delayed placement) failed in the experimental group. There were significant differences in the percentage of bone-to-implant contact and marginal bone volume density between the control and the experimental groups. Both parameters were significantly lower in the experimental group than in the control group (P<0.05). There was a tendency toward more marginal bone loss in the experimental group than the control group.

Conclusion: Immediately placed implants have a higher failure rate than delayed placed implants. Untreated experimental periodontitis was correlated with a compromised osseointegration in delayed placed implants.