Masticatory function improvement with the use of mandibular single-implant overdentures in edentulous subjects: a systematic literature review.

Introduction: In this systematic review, several masticatory function parameters assessed during mandibular single-implant overdenture (SIO) use were compared to pre- SIO placement values in edentulous patients with aim of contributing to a consensus regarding denture treatment options.

Evidence acquisition: This study was registered a priori in the PROSPERO database (CRD42018106567). Two independent reviewers carried out electronic searches in eight databases, without language or time frame limitations, to collate clinical studies comparing masticatory function of edentulous patients before versus after SIO installation with the implant placed on the mandibular midline. Risk of bias was assessed with a before-and-after tool and evidence certainty level was evaluated with the Grading of Recommendations Assessment, Development and Evaluation program.

Evidence synthesis: Eleven studies were included in this review (1 prospective, 3 crossover trials, 4 randomized clinical trials, 2 paired clinical trials, and 1 pilot). Enrolled patients were mostly over 60 years old; all patients were using conventional complete dentures (CD) prior to SIO installation. Masticatory performance, masticatory efficiency, bite force, and muscle activity were improved after the SIO placement compared to during mandibular CD use. Mandibular movement and masticatory ability data were inconclusive. Most of the studies had low risk of bias, but all had very low certainly level ratings due to methodological heterogeneity.

Conclusions: Placement of SIO improves masticatory function, as reflected mostly by masticatory performance and efficiency data, relative to CD use. Further studies comparing dental rehabilitation options, including SIOs, are needed to improve the quality of evidence in the literature.