Early implant placement in ridge preserved extraction sockets: A pre‐clinical in vivo study

Objectives The aim was to analyse the outcomes of early implant placement after 6 and 12 weeks of healing in ridge preserved sites in a canine model. Materials and methods Implants were placed in second maxillary incisors sites in 9 dogs 6 weeks after grafting of the sockets with 90% deproteinized bovine bone mineral in 10% collagen matrix (DBBMC) and closure with resorbable type I/III porcine collagen matrix (PCM). The implants were randomly assigned to 6 (T6) and 12 (T12) weeks of healing. Results The percentage of bone‐to‐implant contact (%BIC), old bone, new bone and residual DBBMC was similar between T6 and T12. In relation to the implant shoulder (IS), the original bone crest (IS‐ROB) was more apical on the buccal than the palatal side. The regenerated bone crest (IS‐C) and IS‐ROB were similar between groups. However, the distance from IS to first bone‐to implant contact (IS‐fBIC) was significantly less in T12 compared with T6 (p = .022; Wilcoxon signed‐rank test). The bucco‐palatal ridge dimensions between T6 and T12 were similar. Conclusions This study confirms that implants can successfully be placed early in ridge preserved maxillary second incisor sites and are osseointegrated by 6 weeks. There were significantly lower IS‐fBIC values at 12 weeks than at 6 weeks on the buccal aspect. The original buccal bone crest underwent greater corono‐apical resorption than the palatal crest. The %BIC, relative proportions of mineralized tissues and dimensions of the alveolar ridge demonstrated stability between 6 and 12 weeks of healing.