Assunção, Wirley Goncalves [UNESP]Barão, Valentim Adelino Ricardo [UNESP]Delben, Juliana Aparecida [UNESP]Gomes, Érica Alves [UNESP]Garcia, Idelmo Rangel [UNESP]2014-05-272014-05-272011-01-01Journal of Prosthodontic Research, v. 55, n. 1, p. 12-18, 2011.1883-1958http://hdl.handle.net/11449/72248Purpose: The aim of this study was to evaluate the effect of different levels of unilateral angular misfit on preload maintenance of retention screws of single implant-supported prostheses submitted to mechanical cycling. Materials and methods: Premachined UCLA abutments were cast with cobalt-chromium alloy to obtain 48 crowns divided into four groups (n=12). The crowns presented no misfit in Group A (control group) and unilateral misfits of 50μm, 100μm and 200μm in the groups B, C and D, respectively. The crowns were attached to external hexagon implants with a titanium retention screw with torque of 30N/cm. Oblique loading of 130N at 2Hz was applied on each replica, totalizing 5×104 and 1×106cycles. Detorque values were measured initially and after each cycling period. Data were evaluated by analysis of variance and Tukey's HSD test (p<0.05). Results: All groups presented reduced initial detorque values (p< 0.05) in comparison to the insertion torque (30. ± 0.5. N/cm) and Group A (25.18. N/cm) exhibited the lowest reduction. After mechanical cycling, all groups presented detorque values from 19.5. N/cm to 22.38. N/cm and the mechanical cycling did not statistically influence the detorque values regardless the misfit level of the replicas. Conclusion: The unilateral misfit influenced the preload maintenance only before mechanical cycling. The mechanical cycling did not influence the torque reduction. © 2010 Japan Prosthodontic Society.12-18engDental implantImplant-supported prosthesisMechanical cyclingMisfitPreloadchromium derivativedental alloydental caredenturemechanical stressmethodologyprosthesistooth crowntooth prosthesistorqueChromium AlloysCrownsDental AbutmentsDental AlloysDental Prosthesis DesignDental Prosthesis RetentionDental Prosthesis, Implant-SupportedDental Stress AnalysisProsthesis FittingStress, MechanicalTorqueArtigo10.1016/j.jpor.2010.05.002Acesso restrito2-s2.0-786497262554438747643373395