Influence of Implant Timing on Peri-Implant Tissue Healing in Interradicular Septal Bone: A Preclinical in Vivo Study.

Aim

This study aimed to assess the influence of implant timing on peri-implant tissue healing and osseointegration around implants placed in the interradicular septal bone of multirooted teeth.

Materials And Methods

In seven beagle dogs, the mandibular second and third premolars with bifurcated roots were extracted. Bone-level implants were placed into the septal bone according to four experimental protocols: Immediate (0 week), Early-1 (2 weeks), Early-2 (4 weeks), and Delayed (8 weeks). All animals were euthanized 16 weeks after tooth extraction. Histomorphometric analysis was performed to assess bone-to-implant contact (BIC), first bone-to-implant contact (fBIC) at the mesial and distal aspects, and peri-implant soft tissue dimensions. Radiographic analysis using micro-computed tomography (micro-CT) was additionally performed to assess fBIC at the buccal and lingual aspects. Statistical analyses were performed using repeated-measures ANOVA for BIC and the Friedman test for fBIC and peri-implant soft tissue parameters, with a significance level set at p < 0.05. Normality and sphericity were confirmed for BIC via Shapiro-Wilk and Mauchly's tests, respectively.

Results

Buccal fBIC values gradually decreased with longer healing periods prior to implant placement (Immediate: 3.21 mm; Early-1: 2.77 mm; Early-2: 2.09 mm; Delayed: 1.82 mm), whereas mesial, distal, and lingual fBIC values were < 1 mm in all groups. None of the intergroup differences in fBIC reached statistical significance. BIC values were also comparable among the groups (54.48%, 48.40%, 45.18%, and 54.54%, respectively). Similarly, peri-implant soft tissue measurements, including gingival margin-to-fBIC (3.17-4.04 mm) and junctional epithelium-to-fBIC (1.27-1.96 mm), did not differ significantly among the groups.

Conclusion

Implant placement performed immediately or at 2, 4, and 8 weeks after tooth extraction without additional bone grafting resulted in successful osseointegration in all groups, with no statistically significant differences in peri-implant tissue healing among the experimental groups.