Microstrain around dental implants supporting fixed partial prostheses under axial and non-axial loading conditions, in vitro strain gauge analysis.
The current study used strain gauge analysis to perform an in vitro evaluation of the effect of axial and non-axial loading on implant-supported fixed partial prostheses, varying the implant placement configurations and the loading points. Three internal hexagon implants were embedded in the center of each polyurethane block with in-line and offset placements. Microunit abutments were connected to the implants using a torque of 20 N · cm, and plastic prosthetic cylinders were screwed onto the abutments, which received standard patterns cast in Co-Cr alloy (n = 10). Four strain gauges (SGs) were bonded onto the surfaces of the blocks, 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 using a 10-N·cm torque, and axial and non-axial loads of 30 kg were applied at 5 predetermined points. The data obtained from the strain gauge analyses were analyzed statistically through the repeated measures analysis of variance and the Tukey test, with a conventional level of significance of P < 0.05. The results showed a statistically significant difference for the loading point (P = 0.0001), with point E (nonaxial) generating the highest microstrain (327.67 μ[Latin Small Letter Open E]) and point A (axial) generating the smallest microstrain (208.93 μ[Latin Small Letter Open E]). No statistically significant difference was found for implant placement configuration (P = 0.856). It was concluded that the offset implant placement did not reduce the magnitude of microstrain around the implants under axial and non-axial loading conditions, although loading location did influence this magnitude.
From the Departments of *Dental Materials and Prosthodontics †Bioscience and Buccal Diagnosis, and ‡Social Dentistry and Children's Clinic, School of Dentistry of São José dos Campos, São Paulo State University (UNESP), São Jose dos Campos, Brazil.
Luis Gustavo Oliveira
LG
de Vasconcellos
Renato Sussumu
RS
Nishioka
Luana Marotta Reis
LM
de Vasconcellos
Ivan
I
Balducci
Alberto Noriyuki
AN
Kojima
D001696:Biomechanical Phenomena; D000044:Dental Abutments; D003722:Dental Alloys / Q000737:chemistry; D015921:Dental Implants; D017267:Dental Prosthesis Design; D019094:Dental Prosthesis, Implant-Supported; D003799:Dental Stress Analysis / Q000379:methods; D003779:Denture Design; D003781:Denture Retention / Q000295:instrumentation; D003830:Denture, Partial, Fixed; D006801:Humans; D008422:Materials Testing; D013314:Stress, Mechanical; D019415:Torque
D003722:Dental Alloys; D015921:Dental Implants