Purpose. The purpose of this study was to evaluate the effect of relining of mandibular implant retained overdenture with resilient liner on posterior mandibular ridge resorption.
Material and methods. Twelve completely edentulous patients received 2 implants in the canine area of the mandible and connected with a Dolder bar. Patients were randomly divided in two groups: Group I (non-relined group), patients received bar/clip attachment and acrylic mandibular overdenture without relining. Group II (relined group), patient received bar attachment and acrylic mandibular overdenture totally relined with soft liner (around the bar and the distal extensions of the denture). Proportional measurements in terms of posterior area index (PAI) of the residual ridges were measured on panoramic images of Cone Beam computerized tomography taken after the overdenture insertion (base line, T0) and five years after the overdenture insertion (T5).
Results. Group I demonstrated statistically significant higher mean change in PAI (bone loss) compared to group II. The amount of bone loss was 1.23mm (in group I) and .74mm (in group II) for each 1mm of the residual ridge length. Only group, mandibular bone height, and relining frequencies had a significant correlation with the change in PAI. No significant correlation between age or gender with change in PAI.
Conclusions: Within the limitations of this study, it could be concluded that relined implant retained mandibular overdentures with silicon soft liner over bar attachments is preferred on long term as it reduced posterior mandibular ridge resorption compared to unrelined overdentures