Libros

Purpose: To evaluate the performance of fixed complete dental prostheses supported by axial and tilted implants after at least 3 years of follow-up. Materials and Methods: An electronic search plus a hand search up to April 2021 was undertaken. Clinical studies were selected using specific inclusion criteria, independent of the study design. The main outcomes were cumulative implant survival rate, marginal bone level changes, and complications, after ≥ 3 years of follow-up. The difference in outcomes between axial and tilted implants and between the maxilla and mandible was evaluated using meta-analysis and the Mantel-Cox test. Results: Out of 824 articles retrieved, 24 were included. In total, 2,637 patients were rehabilitated with 2,735 full prostheses (1,464 maxillary, 1,271 mandibular), supported by 5,594 and 5,611 tilted and axial implants, respectively. In a range between 3 and 18 years of follow-up, 274 implants failed. The cumulative implant survival rate was 93.91% and 99.31% for implants and prostheses, respectively. The mean marginal bone level change was moderate, exceeding 2 mm in only two studies. Marginal bone loss was significantly lower around axial compared with tilted implants (P < .0001), whereas it was not affected by arch (maxilla vs mandible; P = .17). Conclusion: Fixed complete dental prostheses supported by tilted and axially placed implants represent a predictable option for the rehabilitation of edentulous arches. Further randomized trials are needed to determine the efficacy of this surgical approach and the remodeling pattern of marginal bone in the long term. Palabras clave: axial implants, immediate loading, mandible, marginal bone loss, maxilla, tilted implants

Purpose: The aim of this prospective study was to establish if ultrashort implants are a reliable therapeutic solution by evaluating their effect on mean crestal bone loss and assessing their survival and success rates. Materials and Methods: Patients were treated using 6-, 9-, and 11-mm-long implants with sandblasted and acid-etched surfaces and fitted with fixed partial prostheses. Clinical and radiographic examinations were scheduled yearly. Data collected included the implant positioning site, implant length and diameter, peri-implant bone loss (PBL), and clinical and anatomical C/I ratios. Results: One hundred eleven implants (6-mm-long, 30.6%) were positioned; two implants were lost before loading. During the 36-month followup, no other implants were lost (98.2% survival rate, 100% from loading), but four implants did not meet the criteria for success, due to excessive crestal bone loss, resulting in a 94.6% success rate, 96.3% from loading. Success rates and peri-implant bone loss were not significantly different among implants with different lengths. No correlation was observed between implant length and bone resorption. Conclusion: Six-millimeter-long implants did not show different results in comparison with 9- and 11-mm-long implants. They can be considered a reliable solution for implant prosthetic rehabilitation and a dependable and minimally invasive therapeutic option in areas showing severe bone resorption. Palabras clave: crown-implant ratio, implant length, implant success rate, prospective study, ultrashort implants

Objective: To test the hypothesis of the outcome of complete arch flapless guided implant surgery mandibular rehabilitations in the presence or absence of a residual band of keratinized mucosa (KM) 6 mm wide in the vestibular-lingual aspect, with and without a modification of the surgical protocol. Method and Materials: Thirty-nine patients were included in this study (12 men and 27 women), with a mean age of 62.5 years (range, 42 to 79 years), divided into 3 groups of 13 patients according to the status of residual band of KM: group 1, KM 6 mm rehabilitated through a modified guided surgical protocol with flap opening to preserve KM; group 2, KM >= 6 mm; and group 3, KM 6 mm; patients from both groups 2 and 3 were rehabilitated through flapless guided implant surgery without modification of the protocol. Group 2 and 3 patients were age- and sex-matched with group 1. Outcome measures were clinical attachment loss (CAL) >= 2 mm after 1 year (backward conditional regression), incidence of dehiscences, dental plaque, bleeding, and implant infections. The level of significance chosen was 5%. Results: Thirty-nine patients with 156 implants were followed for 1 year, and no dropouts occurred. Absence of a residual band of KM >= 6 mm in the vestibular-lingual aspect was significantly associated with CAL (odds ratio, 39.1; P = .036) and dehiscences (P = .003). Conclusion: Within the limitations of this study, the absence of a residual band of KM >= 6 mm wide in the vestibular-lingual aspect in patients rehabilitated in the complete edentulous mandible with flapless guided implant surgery may be associated with CAL and a higher incidence of dehiscences after 1 year of follow-up. This possible association needs to be confirmed in studies with stronger designs and longer follow-ups. Palabras clave: flapless surgery, guided surgery, immediate function, implant

Objectives: This study aimed to evaluate the long-term prognosis of immediately loaded fixed full prostheses for the treatment of edentulous patients with extreme bone atrophy in the posterior mandibular region. Material and Methods: Twenty-four edentulous patients with atrophic posterior mandibles were treated by means of a complete prosthesis sustained by both axial and tilted fixtures. The insertion of tilted implants was carefully planned by means of computed tomography scan analysis and measuring width and height of residual bone. Implant type, length, and diameter were chosen, as well as implant angulation, according to the All-on-Four protocol and avoiding the course of the mandibular nerve. The prosthesis was delivered no later than 2 days after implant surgery. Implant survival and prosthesis success were assessed clinically and radiographically up to 42 months of follow-up. Measurement of peri-implant bone loss was based on periapical radiographs after 12 months of loading. Results: All implants survived and all prostheses were successful at the time of this study reporting. The mean follow-up was 30.1 months with a range of 14 to 44 months. The average peri-implant bone loss was 0.85 mm after 12 months (0.8 mm for tilted implants and 0.9 mm for axial implants). No significant difference in marginal bone loss was observed between axial and tilted implants. Conclusions: The immediate rehabilitation of patients with extreme atrophic mandibles can be successful with careful planning and particular attention during the surgical placement of the implants, as shown by the excellent outcomes of the present study. Palabras clave: endosseous implants, extreme atrophy, immediate loading, mandible, tilted implants

Purpose: This article reports preliminary results of a single-cohort prospective study that sought to evaluate a new surgical protocol for the immediate rehabilitation of edentulous maxilla without using bone grafting. Materials and Methods: Twenty consecutive patients in need of a full-arch maxillary rehabilitation were included in the study. Each patient received four tilted implants that engaged the posterior and the anterior sinus wall and two axial implants in the anterior maxilla. A total of 120 implants (30 Brånemark System MK IV and 90 NobelSpeedy Groovy) was inserted. Acrylic resin provisional prostheses were delivered within 4 hours of implant placement, and definitive restorations were placed 4 to 6 months later. Follow-up visits were scheduled every 6 months for the first 2 years and yearly thereafter. At each follow-up appointment, plaque and bleeding indexes were scored, periapical radiographs were obtained to assess marginal bone level changes, and patient satisfaction was recorded by means of a questionnaire. Results: The follow-up ranged between 18 and 42 months (average, 27.2 months). No implants failed. All prostheses were stable and functional. No adverse events occurred. At 1 year, mean marginal bone loss around axial and tilted implants was similar: 0.8 mm for axial implants (SD 0.4, n = 30) and 0.9 mm for tilted implants (SD 0.5 mm, n = 60) (P > .05). Plaque and bleeding scores decreased over time, and patient satisfaction with both esthetics and function increased. Conclusions: This technique can be considered a viable treatment modality for the immediate rehabilitation of the edentulous maxilla, as it provides optimal support in the posterior region, minimizes distal cantilevers, and avoids bone grafting or sinus augmentation. Palabras clave: dental implants, edentulous maxilla, immediate function, immediate loading, tilted implants

The aim of this study was to evaluate stress patterns at the bone-implant interface of tilted versus nontilted implant configurations in edentulous maxillae using finite element models of two tilted and one nontilted configuration. Analysis predicted the maximum absolute value of principal compressive stress near the cervical area of the distal implant for all models. The tilted configurations showed a lower absolute value of compressive stress compared with the nontilted, indicating a possible biomechanical advantage in reducing stresses at the bone-implant interface.