The effect of different manufacturing techniques on the fit of impant supported fixed prosthesis to implants

Implant-supported treatment options are frequently preferred because of the high wearing comfort of patients, tooth and bone tissue preservation. Due to the biomechanical behavior of the implants, the fit of the implant-supported prosthesis is more important than that of tooth-supported prostheses. Especially distortions that may occur during the manufacturing stages of screw retained prostheses may cause overloads to implants and supported bone tissue after the screws are tightened. Nowadays, CAD / CAM technology stands out for the manufacturing of more passive fitting prostheses. Despite the developments in full ceramic systems, metal-ceramic systems maintain their place as the gold standard especially in long-span and full-arch prosthesis. In metal-ceramic systems, the high temparature applied during the ceramic application phase may cause some distortions in the metal framework. For this reason, we investigated the effect of different techniques on the distortion of the frameworks by using 10 CAD / CAM and 20 cast technique fabricated full-arch lower jaw prosthesis. We also encountered the distortions of porcelain application stages on CoCr frameworks produced by different techniques. In our evaluation, it was found that the frameworks manufactured with CAD/CAM system had better fit and were less affected by porcelain application stages