Effect of axial loads on implant-supported partial fixed prostheses by strain gauge analysis.
OBJECTIVE
The present study used strain gauge analysis to perform an in vitro evaluation of the effect of axial loading on 3 elements of implant-supported partial fixed prostheses, varying the type of prosthetic cylinder and the loading points.


METHODS
Three internal hexagon implants were linearly embedded in a polyurethane block. Microunit abutments were connected to the implants applying a torque of 20 Ncm, and prefabricated Co-Cr cylinders and plastic prosthetic cylinders were screwed onto the abutments, which received standard patterns cast in Co-Cr alloy (n=5). Four strain gauges (SG) were bonded onto the surface of the block tangentially to the implants, SG 01 mesially to implant 1, SG 02 and SG 03 mesially and distally to implant 2, respectively, and SG 04 distally to implant 3. Each metallic structure was screwed onto the abutments with a 10 Ncm torque and an axial load of 30 kg was applied at five predetermined points (A, B, C, D, E). The data obtained from the strain gauge analyses were analyzed statistically by RM ANOVA and Tukey's test, with a level of significance of p<0.05.


RESULTS
There was a significant difference for the loading point (p=0.0001), with point B generating the smallest microdeformation (239.49 µε) and point D the highest (442.77 µε). No significant difference was found for the cylinder type (p=0.748).


CONCLUSIONS
It was concluded that the type of cylinder did not affect in the magnitude of microdeformation, but the axial loading location influenced this magnitude.
Department of Dental Materials and Prosthodontics, São José dos Campos Dental School, São Paulo State University, São José dos Campos, SP, Brazil. lgovasconcellos11@terra.com.br
Luis Gustavo Oliveira de
LG
Vasconcellos
Renato Sussumu
RS
Nishioka
Luana Marotta Reis de
LM
Vasconcellos
Lea Nogueira Braulino de Melo
LN
Nishioka
D000704:Analysis of Variance; D002858:Chromium Alloys / Q000737:chemistry; D000044:Dental Abutments; D015921:Dental Implants; D017267:Dental Prosthesis Design; D019094:Dental Prosthesis, Implant-Supported; D003799:Dental Stress Analysis / Q000379:methods*; D006801:Humans; D008422:Materials Testing; D013314:Stress, Mechanical; D013499:Surface Properties; D019415:Torque
D002858:Chromium Alloys; D015921:Dental Implants