Relation between implant/abutment vertical misfit and torque loss of abutment screws.
This study investigated whether there is a direct correlation between the level of vertical misfit at the abutment/implant interface and torque losses (detorque) in abutment screws. A work model was obtained from a metal matrix with five 3.75 x 9 mm external hex implants with standard platform (4.1 mm). Four frameworks were waxed using UCLA type abutments and one-piece cast in commercially pure titanium. The misfit was analyzed with a comparator microscope after 20 Ncm torque. The highest value of misfit observed per abutment was used. The torque required to loose the screw was evaluated using a digital torque meter. The torque loss values, measured by the torque meter, were assumed as percentage of initial torque (100%) given to abutment screws. Pearson's correlation (alpha=0.05) between the misfit values (29.08 +/- 8.78 microm) and the percentage of detorque (50.71 +/- 11.37%) showed no statistically significant correlation (p=0.295). Within the limitations of this study, it may be concluded that great vertical misfits dot not necessarily implies in higher detorque values.
Barbosa
Gustavo Augusto Seabra
GA
Department of Dentistry, Federal University of Rio Grande do Norte, Natal, RN, Brazil.
Bernardes
Sérgio Rocha
SR
das Neves
Flávio Domingues
FD
Fernandes Neto
Alfredo Júlio
AJ
de Mattos
Maria da Glória Chiarello
Mda G
Ribeiro
Ricardo Faria
RF
D000044:Dental Abutments; D003758:Dental Implantation, Endosseous / Q000009:adverse effects*; D015921:Dental Implants / Q000009:adverse effects*; D017268:Dental Prosthesis Retention / Q000295:instrumentation*; D019094:Dental Prosthesis, Implant-Supported; D019232:Dental Restoration Failure; D003799:Dental Stress Analysis; D003765:Models, Dental; D017755:Prosthesis Fitting; D019415:Torque
D015921:Dental Implants