Long-term Survival Rates of Implants Supporting Overdentures

Abstract

The study aims were to evaluate survival rates of dental implants in patients wearing maxillary and mandibular overdentures in relation to age, sex, smoking, implant splinting or non-splinting, the maxilla rehabilitated, and number of implants per dental arch. This was a prospective study of patients who were completely edentulous in either mandible or maxilla or both, rehabilitated with implant-retained overdentures, with a follow-up of at least 3 years. 95 patients with 107 overdentures were supported by 360 implants were included in the study. Rehabilitations were monitored over an average of 95 ± 20.3 months (range 36-159). Implant survival in the maxilla was 91.9% and in the mandible 98.6%, representing a statistically significant difference (P < .05). Age, sex and implant splinting did not influence survival rates significantly. Smokers presented a lower survival rate. Implant numbers in the maxilla had a significant influence on survival, 100% for 6 but 85.7% for 4. Three mandibular implants achieved higher survival rates (100%) but with 2 (96.6%) or 4 (99%) survival was lower, although without significant difference. Long-term results suggest that 3-implant mandibular overdentures have an equivalent survival rate to 4-implant overdentures. In the maxilla, results showed that 6 implants may be the best treatment strategy. For smokers with fewer implants retaining the overdentures, there were higher numbers of implant failures.

Maxillary Overdenture Retained with an Implant Support CAD-CAM Bar: A 4 Years Follow Up Case

“…The oral rehabilitation of edentulous jaw by combining 4 implants, 2 straight medially and 2 tilted distally, was developed to overcome the anatomic limitations related to bone loss, and where it is difficult to treat the patients without complex augmentative techniques [3, 4]…”

Comparative study of splinted and unsplinted implant-retained maxillary overdentures without palatal coverage: A literature review

“…In fact, the great majority of the studies showed different numbers of implants for the rehabilitation of maxillary edentulous patients. It has been reported in long terms of results that the installation of six implants in the maxilla would be the best strategy to obtain good dental implants survival rates [30,34]. Therefore, the use of six implants for maxillary IODs was expected to present satisfactory results by performing a favorable distribution of the masticatory loads under the prosthesis, but with a higher cost and, eventually, with a bone grafting requirement.…”

Evidence‐Based Criteria for Differential Treatment Planning of Implant Restorations for the Maxillary Edentulous Patient

“…The resorptive pattern of the maxilla, when extensive, may also lead to dissatisfaction with certain prosthetic designs, since almost 90% have a smile extended to second premolars, which impacts buccal corridor esthetics . Given these risk factors, it is not surprising that the survival rate and patient satisfaction of maxillary implant prostheses is lower than similar data reported on the mandible . Because of these challenges, there continues to be controversy on the appropriate implant treatment for the edentulous maxilla.…”

“…Three assessments are critical to a proper selection of prosthetic design: esthetic factors, occlusal vertical dimension (OVD), and radiographic data . The preference of a removable design will be influenced by the need for lip and cheek support, which often can be predicted by the thickness of a buccal flange of an existing complete denture .…”

“…In a recent consensus report, Godfredsen et al noted that there were no RCTs available to demonstrate that a particular number of implants for maxillary IODs offered better biological, technical, or patient‐mediated outcomes. However, Balaguer et al in a longitudinal prospective study (36‐ to 159‐month follow‐up) of 107 maxillary overdentures reported a significantly higher implant survival with six implants compared to four. In a meta‐analysis on maxillary IODs, Slot et al also reported a statistical difference in four‐ and six‐implant designs.…”