Immediate loading of two unsplinted mandibular implants in edentulous patients with an implant-retained overdenture: an observational study over two years.

OBJECTIVES Immediate loading of two unsplinted mandibular implants by means of an overdenture may be a viable and cost-effective treatment option to improve the patient's oral health-related quality of life. We therefore conducted a prospective observational study to estimate implant survival and patient satisfaction after an immediate loading protocol in edentulous patients. MATERIALS AND METHODS Twenty edentulous patients who received two interforaminal implants (Straumann Standard implant, length 12 mm) were included in our study. Immediately after implant placement, ball attachments with a diameter of 2.25 mm were placed on the implants and the respective matrices were directly incorporated in the existing complete denture. Clinical recalls were scheduled 1 week, 1, 3, 6 months, and 1 and 2 years after implant placement. The following clinical parameters were assessed: gingival bleeding index (GBI), visual plaque index (VPI), and soft tissue overgrowth. In addition, we also assessed radiological bone level change (RBLC) using panoramic radiographs, and patient satisfaction using a visual analogue scale at baseline, after 6 months and 2 years. RESULTS No implant failures occurred during the 2-year observation period, resulting in a survival rate of 100%. The mean RBLC was 0.67 mm (95% Confidence Interval [95% CI]: 0.47-0.86 mm) two years after surgery. The GBI and VPI after two years were 24 (95% CI: 9-38)% and 36 (95% CI: 19-53)%, respectively. Soft tissue overgrowth was 1.6 mm (95% CI: 1.1-2.1) on average after two years. In a multivariate regression model, patients with a GBI ≥50% on average showed an increased RBLC (-0.6 mm, p = 0.007). High patient ratings were recorded for overall satisfaction. Overall patient satisfaction measured on a scale between one and ten was 5.2 (95% CI: 2.1-8.5) before implant placement and 9.5 (95% CI: 9.1-10) after 2 years. CONCLUSION Immediate loading of two unsplinted interforaminal implants in overdenture patients using ball attachments is a clinically viable treatment option that leads to a high survival rate and oral health-related quality of life.