Are Root-Supported Overdentures Still an Alternative to Implant-Supported Overdentures? A Scoping Review

Purpose To compare the outcomes of prosthodontic treatment for subjects wearing a complete maxillary denture opposing a root-supported mandibular overdenture (RSO) or an implant-supported mandibular overdenture (ISO). Methods A literature search was performed in seven electronic databases: MEDLINE via PubMed interface, Embase, Cochrane Library, Cumulative Index to Nursing and Allied Health Literature, Scopus, Web of Science, and AgeLine. The search terms were developed by the primary investigators and the health sciences librarian, who then started with PubMed and adapted the original search strategy for the other databases. Included articles were those that compared the outcomes for mandibular RSOs and those with ISOs, for persons wearing a maxillary complete denture. Results Seven articles were included in the review. There were limitations in this review because of small sample sizes, short study durations, and different methodologies. Also, no comparative studies were identified for clinically important outcomes, such as survival rates of abutments, prosthodontics/maintenance problems, and longitudinal cost of care. For prosthodontic complications, patient satisfaction, and ability to clean, no differences were reported. For oral tactile sensibility, RSOs presented significantly improved sensibility, whereas ISOs had higher maximum bite force capability, but the difference was not statistically significant, except when subjects had a cross-bite or a lingualized occlusion. Conclusions The results of this scoping review were not conclusive, except for maximum bite force, where ISOs seem to perform better than RSOs by the measured criteria. ISOs had higher survival rates than RSOs, and required less maintenance, but were more expensive. It was disappointing to find so few studies comparing these clinical treatment modalities, which suggests that either treatment may be clinically acceptable and depends upon a shared decision between patients and their dentists.