Comparative clinical study of conventional dental implant and mini dental implant-retained mandibular overdenture: a 5- to 8-year prospective clinical outcomes in a previous randomized clinical trial

Abstract

Objectives: To compare the long-term prospective clinical outcomes in a previous randomized controlled clinical trial (RCT) of 2 Mini Dental Implant (2MDI), 4 Mini Dental Implant (4MDI), and 2 Conventional Dental Implant (2CDI)-retained mandibular overdenture with follow-up between 5 to 8 years. Materials and Methods: Thirty-seven patients formerly participated in Comparative Clinical Study of CDI and MDI for Mandibular Overdenture were requested for examination of clinical outcomes. A total of 104 implants were placed with mean follow-up periods 6.64±0.60 years. In Groups 1 (2MDI) and Group 2 (4MDI), implants were placed and immediately loaded with Equator® attachments to retained mandibular overdenture. In group 3 (2CDI), implants were placed and delayed 3 months for denture loading with ball attachment. Success rate, survival rate, clinical implant performance scale (CIP scale), peri-implant tissue status, prosthetic complication, implant stability quotient (ISQ), marginal bone level change (MBLC), and patient satisfactions were analyzed. Results: After 5 to 8 years follow-up, success rate in Group 1, 2, and 3 were 90.91%, 93.33%, and 54.55%, respectively. The success rate in Group 3 was significantly lesser than Group 1 (p=0.016) and Group 2 (p<0.001). Survival rate in Group 1, 2, and 3 were 100%, 96.67%, and 90.91%, respectively, and showed no significant differences. Mean ISQ reported no significant differences between groups. Mean MBLC were 0.57±1.19 mm, 0.68±0.90 mm and 1.55±1.60 mm in Group 1, 2, and 3, respectively. Group 3 reported significantly greater mean MBLC than Group 1 (p=0.016) and Group 2 (p=0.011), but Group 1 and 2 were not significantly differences. The overall patient satisfactions were reported as not significant differences between groups. Conclude: Two MDI-retained mandibular overdentures with immediate loaded protocol performed had favorable clinical outcomes, cost effectiveness, and overall patient satisfactions after 5 to 8 years follow-up.