Histomorphologic and histomorphometric evaluation of various endosseous implant healing chamber configurations at early implantation times: A study in dogs

Aim: The objective of this study was to evaluate the early healing of endosseous implants presenting various healing chamber configurations in a beagle dog mandible model. Methods: The four premolars of 12 beagle dogs were extracted and allowed to heal for a period of 8 weeks. Implants allowing six different healing chamber configurations were placed in each dog (three per side, six configurations per dog). The animals were sacrificed after 3 and 5 weeks in vivo (n=6 per time in vivo), and the implants were non-decalcified processed to slides of ∼30 μm thickness. Bone-to-implant contact (BIC) and bone area fraction occupied (BAFO) within the healing chamber were quantified. Statistical analysis was performed by a GLM ANOVA model at 5% significance level. Results: Osseointegration and healing with woven bone filling throughout all healing chambers was observed. Replacement of woven bone by lamellar bone showing primary osteonic structures was observed at 5 weeks. BIC was significantly affected by healing chamber configuration (P<0.001) and was not affected by time in vivo (P>0.42) at 3 and 5 weeks in vivo. BAFO was not affected by healing chamber configuration (P>0.14) however significantly increased over implantation time (P<0.001). Conclusion: Regardless of healing chamber design and dimensions considered, healing allowed the devices osseointegration. However, healing chamber configuration significantly affected osseointegration measurable parameters such as BIC.