Histologic Assessment of Peri-implant Tissues Around Endosseous Dental Implants Placed Along with Intentionally Retained Root Fragment in Animal Models: A Systematic Review.

Purpose: To evaluate whether the placement of endosseous dental implants along with intentionally retained root fragments enhances peri-implant histologic characteristics and outcomes in healthy animal models.

Materials And Methods: Two review authors independently performed electronic literature searches across the PubMed/MEDLINE, LILACS, EBSCOhost, and Science Direct databases by using different keywords and Medical Subject Headings terms to identify relevant articles. Only preclinical animal trials evaluating the histology of peri-implant tissues around endosseous dental implants placed along with intentionally retained root fragments were included in the review. The risk of bias assessment was investigated using the Systematic Review Centre for Laboratory animal Experimentation (SYRCLE) tool, and the reporting quality of each trial was evaluated using the Animal Research: Reporting in Vivo Experiments guidelines.

Results: Seven preclinical trials including a total of 33 animals and 155 endosseous dental implants were eligible for the analysis. One trial reported the histologic assessment of peri-implant tissues around endosseous dental implants with ankylotic root fragments, whereas the other six studies used nonankylotic root fragments. The effects of the length of retained root fragments on peri-implant tissues were reported in two trials that showed contrasting results. The effects of the width of retained root fragments were assessed in two trials reporting that a remaining thickness < 2 mm and buccal bone thickness > 3 mm favors alveolar bone preservation over a period of 12 weeks. Although the mean quality assessment score for all preclinical trials was moderately high, the summary for the risk of bias presented a high risk.

Conclusion: Limited data and short-term preclinical evidence showed optimal peri-implant histologic findings of endosseous dental implants placed along with intentionally retained root fragments. However, further preclinical histologic evaluation with homogenous populations and long-term controlled clinical studies are needed to substantiate its applicability in clinical situations.