en پروتزهای دندانی Prothtodontics پژوهشي Research <p> <strong>Objectives</strong> To evaluate the incidence of prosthetic complications in implant-retained crowns made with UCLA castable abutments and to identify possible risk factors with a view to establishing recommendations to help predict the success of such restorations. </p><p> <strong>Methods</strong> A cohort follow-up study was carried out in 71 partially dentate patients rehabilitated with 93 implant-retained single crowns. Data regarding socio-demographic background, anatomical features, implant-, and prosthesis-related variables were recorded. The incidence rate (%), relative risk (RR) and odds ratio (OR) were applied for predictive risk factors. ANOVA and Student t-tests were used to compare quantitative variables, the chi-square test was used to compare proportions and also a logistic regression analysis was performed. The statistical significance was set at α=0.05. </p><p> <strong>Results</strong> Two implants (2.2%) were lost during the first year of function. The incidence of prosthetic complications in the observed mean period (26.2±15.4 months) was 11.9%, consisting of screw loosening (10.8%) and ceramic fracture (1.1%). A higher tendency for prosthetic complications was noticed in posterior mandibular crowns restoring saddles longer than 10mm with mesiodistal cantilevers longer than 6mm, having natural antagonists, after long-term use (>20 months), with initial torque values superior than 30Ncm. </p><p> <strong>Conclusions</strong> Screw loosening is the most frequent complication in implant-retained crowns fabricated with UCLA abutments cast in cobalt–chromium. Nevertheless, the connection usually remains stable after retightening the screws. A high survival rate was recorded, and these prostheses may be a suitable treatment option. </p><p> <strong>Clinical significance</strong> Based on the study findings, the risk of prosthetic complications is expected to increase when long-span posterior edentulous areas are rehabilitated with single implant-supported crowns. The antagonist occlusal plane should be restored to prevent torsional forces and overloading. Implant systems with initial torque values less than 30Ncm should be selected. </p><hr><p></p><p> <strong>Source: </strong>Journal of Dentistry </p><p><a href="http://www.jodjournal.com/article/S0300-5712(12)00239-4/abstract" target="_blank"><font color="#0033ff"> Full Text</font></a></p> Dental implants, UCLA castable abutments, Cobalt–chromium, Implant-supported crowns, Screw loosening, Ceramic fracture 0 0 http://idai.ir/browse.php?a_code=A-10-32-828&slc_lang=en&sid=1 Javier Montero 10031947532846003620 10031947532846003620 No Department of Surgery, Faculty of Medicine, University of Salamanca (USAL), C/Alfonso X el Sabio, s/n, Campus de Unamuno, E-37007 Salamanca, Spain Guillermo Manzano 10031947532846003621 10031947532846003621 No Department of Surgery, Faculty of Medicine, University of Salamanca (USAL), C/Alfonso X el Sabio, s/n, Campus de Unamuno, E-37007 Salamanca, Spain David Beltrán 10031947532846003622 10031947532846003622 No Department of Surgery, Faculty of Medicine, University of Salamanca (USAL), C/Alfonso X el Sabio, s/n, Campus de Unamuno, E-37007 Salamanca, Spain Christopher D. Lynch 10031947532846003623 10031947532846003623 No Tissue Engineering & Reparative Dentistry, School of Dentistry, Heath Park, Cardiff, UK María-Jesús Suárez-García 10031947532846003624 10031947532846003624 No Department of Buccofacial Prostheses, Faculty of Dentistry, Complutense University of Madrid (UCM), Pza. Ramón y Cajal, s/n, E-28040 Madrid, Spain Raquel Castillo-Oyagüe 10031947532846003625 10031947532846003625 Yes Department of Buccofacial Prostheses, Faculty of Dentistry, Complutense University of Madrid (UCM), Pza. Ramón y Cajal, s/n, E-28040 Madrid, Spain