Radiographic Evaluation of Crestal Bone Level Changes for Allografts or Xenografts Placed during Implant Placement: A Retrospective Study

Abstract

The aim of this study was to evaluate initial peri-implant crestal bone level changes when the allografts and xenografts were placed simultaneously during the implant placement. This retrospective study was planned with the convenient sampling total of 77 implant sites that were bone grafted either with allografts (group I) or xenografts (group II). Using the periapical radiographs obtained after placement of bone grafts as baseline, the changes in the alveolar crestal bone around the implants were evaluated by comparing periapical radiographs taken at 3 months and 6 or 8 months after the surgery. The alveolar bone loss at crestal region at the time of placement of bone grafts were -1.85 ± 1.26 mm at the xenograft sites and -1.75 ± 1.51 mm at allograft sites, respectively (p = 0.791). At the time of reentry, 3 months after tooth extraction and ridge preservation, the bone dimensions were 1.17 ± 0.83 mm for xenograft and 1.00 ± 1.14 mm for allograft (p = 0.523). At the final reentry, bone-grafted sites were divided into after 6 months and after 8 months postoperatively. After 3 months, the allografts showed lesser bone resorption (0.9 ± 0.52 mm) as compared with the xenografts (1.25 ± 1.00 mm). The bone loss after 8 months for the allografts was spiked to 1.83 ± 0.42 mm as compared with the xenografts 1.37 ± 1.12 mm with no statistically significant difference (p >0.05). Both allografts and xenografts present comparable crestal bone level changes around dental implants when simultaneously placed during implant placement surgery. Both allografts and xenografts are suitable for the preservation of the alveolar ridge regarding crestal bone level changes. Selection of allografts and xenografts may not be carried out based upon the crestal bone level changes.