Examining the Fracture Strength of Implant-based Fixed Partial Prostheses with Different Dimensions of Connectors in the System CAM/CAD/Zir

Abstract

This study investigated the fracture strength of fixed partial prostheses based on implants. Restoration of shape, function, comfort, beauty, speech and health in edentulous and semi-edentulous patients is one of the goals of modern dentistry, and today it is possible to achieve these goals through treatment with dental implants. Despite the fact that dental implants are a suitable replacement for lost teeth. Implant-based prosthetic treatments have various biological and biomechanical problems. Prosthetic complications in implant-based restorations are very diverse and include mechanical problems in prefabricated components of the implant, such as loosening or breaking of the abutment screw, and technical complications such as ceramic chipping and frequent loss of cement. Also, the loss of interproximal contact between the implant-based fixed prosthesis and the adjacent tooth has been reported, which causes problems such as food entrapment, periodontal defects, and caries of the adjacent tooth. The survival rate and complications of implant-based fixed restorations have been investigated, and a high rate of mechanical complications after a five-year period has been reported. It has been shown that despite the high survival rate of fixed prostheses based on implants, biological and technical problems were common. The most common complication in single-unit prostheses based on the implant is loosening of the abutment screw, and its rate is reported between 5% and 48%. This complication may not cause the failure of the treatment, but it is significantly related to the time and cost required for maintenance and has a negative effect on the patient's satisfaction with the implant treatment. Abutment screw loosening is somewhat related to the implant system used and the applied forces. Porcelain failure is the second most common prosthetic complication in implant-based prostheses, and its rate has been reported in different studies between 3.8% in all-ceramic veneers and 3.2% in metal-ceramic veneers. The rate of loss of cement has been reported in different articles in the period of 2.5 years, 1.6%. Different cements are used to bond fixed restorations to implants. This issue, along with different cementing techniques, is effective in the amount of cement loss.