Immediate Loading of Implants Supporting Mandibular Overdentures

Objectives: The aim of this study was to evaluate and present treatment outcomes of mandibular overdentures retained by two unsplinted, immediately-loaded implants and compare these results with those for conventionally-loaded implants.
Methods: 26 edentulous patients (14 females, 12 males) had 2 interforaminal implants placed with a 1-stage protocol. The patients were each treated with a mandibular overdenture supported by ball abutments. In the test group, the overdenture was loaded one week (immediate loading) after surgery and in the control group, the overdenture was loaded three months (conventional loading) after surgery. Implant stability measurements were made with resonance frequency analysis (RFA) technique. An RFA measurement produces an implant stability quotient (ISQ) unit for each implant, which is derived from the stiffness of the implant/bone complex. Standardized clinical and radiographic parameters were recorded at surgery, and after 1, 2, 3, 4, and 6 years.
Results: No implants were lost, and 1.19±0.2 mm marginal bone resorption was noted for all implants after 6 years. The test and control groups had 1.17±0.3mm, and 1.21±0.2mm of marginal bone loss respectively. The ISQ values for the test group was 74.9±3.8 at the time of surgery and 74.5±2.8 at the 6-year follow-up. The control group had mean ISQ values of 75±4.5 and 73.6±2.0 at the time of surgery and 6-year follow-up respectively. There were no stastically significant differences (p>0.05) between the two groups at any follow-up period. Also, the clinical peri-implant parameters (plaque index, bleeding index, probing depths, gingival index) and marginal bone levels exhibited no statistically significant differences between the two groups over 6 years.
Conclusions: The results of this clinical trial show that immediate loading of 15mm-long TiUnite implants supporting mandibular overdentures may be a feasible option to restore edentuluous mandibles.