Retrospective, cross-sectional study on immediately loaded implant-supported mandibular fixed complete-arch prostheses fabricated with the passive fit cementation technique.

STATEMENT OF PROBLEM: Mandibular fixed complete-arch dental prostheses on dental implants have been benefiting patients for a long time, but problems with passive fitting between the metallic framework of the prostheses and the implants might influence its long-term success. PURPOSE: The purpose of this cross-sectional study of immediately loaded mandibular fixed complete-arch dental prostheses was to evaluate the survival and success rates of prostheses, the survival rates of dental implants, the occurrence of complications in the prostheses and implants, participant satisfaction, and the association between cantilever length and prosthesis complications. MATERIAL AND METHODS: Data were collected from the participants' records. The exposure variables were participant related (sex and age) and treatment related (number of implants and length of cantilever). The outcome variables were the survival and success of the prostheses and implants, complications, and participant satisfaction. The Fisher or chi-square tests was used for the association between 2 qualitative variables (α=.05). RESULTS: Two hundred ninety consecutive participants (1429 implants) with a mean follow-up time of 4.4 years were included. The survival rate for the prostheses was 98.6 and the success rate was 96.6%. The implant survival rate was 99.6%. Sixty-seven participants experienced a prosthetic complication, the most common being tooth fracture. Only 2.45% (n=35) of the implants were associated with screw loosening. Of the total number of participants, 86.9% were completely satisfied with their treatment. The length of the cantilever (up to 25 mm) was not associated with complications (P>.05). CONCLUSIONS: Implant-supported mandibular fixed complete-arch dental prostheses fabricated with a passive fit technique provide successful treatment for patients with edentulism. The success and survival rates of implants and prostheses were high. Only straightforward complications were observed. Cantilever length was not associated with complications.

Bone behavior in atrophic edentulous mandibles after rehabilitation with immediate loaded implant: a short-term radiographic and tomographic study.

PURPOSE: To evaluate bone response in the posterior area of edentulous mandibles rehabilitated with fixed prosthesis supported on dental implants considering baseline severity of mandibular atrophy. MATERIAL AND METHODS: The sample included 15 patients in whom 5 implants were inserted between the mental foramens. The prosthesis followed a cantilever extension from 15 to 20 mm. They were divided into 2 groups (severe and moderate) according to the degree of the atrophy presented. Panoramic x-ray and computerized tomography were obtained immediately after rehabilitation (T0) and after 8 months (T8). Linear measurements of the alveolar bone height at the posterior area of the mandible, 5, 10, and 15 mm from the long axis of the most distal implants, were recorded. Density measurements were also achieved at the same sites. RESULTS: A slight bone increase in both groups was observed but with no statistically significant difference according to the baseline degree of atrophy. CONCLUSIONS: There was slight qualitative and quantitative bone improvement in the posterior area of the mandibles with the use of immediately loaded implant-supported fixed prostheses during the observed period. These results suggest that long-term follow-up is very important to understand bone behavior after rehabilitation.