Purpose: To assess the clinical outcomes of maxillary overdentures supported by dental implants by conducting a literature review. Materials and Methods: An electronic search was undertaken in March 2019. Eligibility criteria included publications reporting cases of implant-supported maxillary overdentures with follow-up information. Results: A total of 131 publications were included (1,478 overdentures supported by 6,681 implants). The mean number of attachments per overdenture was 3.8 ± 1.2 (range: 1 to 9), and a bar-clip system was used in about half of the cases. The prostheses were followed up for a mean of 47.9 ± 32.8 (range: 1 to 240) months. A total of 401 implants (6.0%) failed in 219 patients (14.8%), and 55 prostheses (3.7%) failed at a mean of 40.2 ± 53.2 (range: 6 to 240) months after placement. Most of the failures happened within the first year after placement for both implants (52.1%) and prostheses (41.8%). Patients with fewer implants per prosthesis presented higher prosthesis failure rates than patients with more implants per prosthesis. The cumulative survival rate for dental implants after 19 years was 70.4%, and for implant-supported maxillary overdentures was 79.8%. Presence of palatal coverage and/or metallic structure/reinforcement does not seem to have an influence on failure rate. Of the most commonly used attachment systems, the ball/O-ring and the Ceka were the ones with the highest rates of patients having at least one implant failure. Conclusion: Most of the prosthesis failures were due to loss of implants, and the first year was the most critical period for failures. The number of dental implants placed per patient seemed to have an impact on the occurrence of overdenture failure.

The aim of this study was to compare the clinical outcomes of implant-supported overdentures (ODs) with either bar-clip or ball attachments. The implant, prosthesis failure, and technical complications were the outcomes analyzed in this retrospective clinical study conducted in a specialty clinic. Seventy-five patients with 242 implants supported by 76 ODs (36 maxillary, 40 mandibular) were included in the study and followed up for 88.8 ± 82.9 months (mean ± standard deviation). Bar-clip and ball attachments were used in 78.9% and 21.1% of the cases, respectively. Forty-three implant failures (17.8%) in 17 prostheses (17/76; 22.4%) were observed in this study. The average period of implant failure was 43.3 ± 41.0 months, and most of them were maxillary turned implants. The bar-clip system demonstrated more complications in the attachment parts compared to the ball attachment system. Poor retention of the prosthesis was similar between the two systems. Loss of implants resulted in the failure of 10 ODs in this study. ODs opposed by natural dentition or fixed prostheses presented with more complications. The Cox proportional hazards model did not show a significant effect on prosthesis failure for any of the factors. These findings indicated that patients with ODs need constant maintenance follow-ups to address the technical complications and perform prosthodontic maintenance regardless of the attachment system used.

Objectives/aim To analyze and compare costs of different prosthetic rehabilitations for the edentulous maxilla. Materials and methods Patients with edentulous maxillae were rehabilitated with either of three implant-supported prosthetic protocols; removable overdenture supported by 2 implants (ISOD 2), fixed dental prostheses supported by 4 (ISFAFDP 4) or 6 (ISFAFDP 6) implants. Cost of treatment and costs during follow-up were registered and compared. Results Twenty-four patients were included: six patients received ISOD 2 treatment, eight patients received ISFADP 4 treatment and ten patients received ISFADP 6 treatment. Initial costs for ISFAFDP 6 were higher than costs for ISFAFDP 4 and ISOD 2, but there were no differences in cost for maintenance i.e., the ISOD treatment remained the least costly treatment alternative after 1-year follow-up. Discussion The lack of difference in cost for maintenance and repair over the first year suggests that implant-supported overdentures will remain the least costly treatment option for the edentulous maxilla, at least in a short-term perspective. Conclusions Removable maxillary overdentures supported by 2 implants may be a valid low cost treatment option.