Preload and torque removal evaluation of three different abutment screws for single standing implant restorations.
Several authors still consider the mechanical problems of fracture and component loosening as the main causes of failure of implant-supported restorations. The purpose of this in vitro study was to compare the preload of three types of screw for transmucosal abutment attachment used in single implant-supported prosthesis through strain gauge and removal torque measurements. Three external hex fixtures were used, and each received a transmucosal abutment (Cera One), which was fixed to the implant with its respective screw: Group A- gold screw, Group B- titanium screw and Group C- surface-treated titanium screw (Ti-Tite). Ten screws of each type were attached applying a 30.07+/-0.28 Ncm torque force and maintained in position for 5 minutes. After this, the preload values were measured using strain gauges and a measurement cell. Gold screws presented higher preload values (131.72+/-8.98 N), followed by surface-treated titanium screws (97.78+/-4.68 N) and titanium screws (37.03+/-5.69 N). ANOVA (p<0.05) and Tukey's test (p<0.05) were applied. Statistically significant differences were found among the groups for both preload and removal torque values. In conclusion, gold screws may be indicated to achieve superior longevity of the abutment-implant connection and, consequently, prosthetic restoration due to greater preload values yielded.
Stüker
Rafael Augusto
RA
Pontifical Catholic University of Rio Grande do Sul, Porto Alegre, RS, Brazil. rafaelstuker@yahoo.com.br
Teixeira
Eduardo Rolim
ER
Beck
João Carlos Pinheiro
JC
da Costa
Nilza Pereira
NP
D020099:Coated Materials, Biocompatible / Q000737:chemistry; D000044:Dental Abutments; D019250:Dental Implants, Single-Tooth; D003764:Dental Materials / Q000737:chemistry; D017267:Dental Prosthesis Design; D017268:Dental Prosthesis Retention; D019094:Dental Prosthesis, Implant-Supported; D019232:Dental Restoration Failure; D006047:Gold Alloys / Q000737:chemistry; D006801:Humans; D008422:Materials Testing; D013314:Stress, Mechanical; D013997:Time Factors; D014025:Titanium / Q000737:chemistry; D019415:Torque
D020099:Coated Materials, Biocompatible; D003764:Dental Materials; D006047:Gold Alloys; D014025:Titanium