The Relationship of Zirconium Thickness Used in Crown Bridge Prosthesis with Tooth Preparation

Abstract

The aim of this in vitro study is to investigate the relationship of two different crown preparations (conventional cutting and guide groove cutting methods) with the ideal thickness of Monolithic Zirconium Crowns used in crown bridge prostheses. For our study, 39 prefabricated lower right molar teeth (no: 46) placed on the Frasaco phantom mandible were used. These prefabricated teeth were scanned with the Sirona Cerec imaging system. Sixteen of these teeth were prepared with the classical method, while the other twenty-three teeth were prepared with guide slotted tooth cutting. Then, saggital and frontal sections of the images between the prepared crown and the original were taken with the Cerec system, and the material removal thicknesses were examined for both sections. 3D scans of each cut prefabricated tooth were standardized from 9 regions that we took as reference. 3D scans made with CAD-CAM were sent to 3D4U Teknoloji LTD.ŞTİ. The measurements made by the company on 3D scans were tabulated to show the averages of each practitioner, and the numerical values were analyzed statistically, grouping as Guide slotted cutting system and conventional method cutting system, and the measurements were compared. For the study, two different cross-section measurements were made, consisting of 4 measurement points in the sagittal and 5 measurement points in the frontal. The cuts were made by five different practitioners. Cut measurements of five different practitioners were generally made with two different methods. The measurements were compared by grouping them as guide slotted cutting system (ROK) and classical conventional cutting system (KK). The averages of AK, Ufuk and Ref sections were calculated for the guide grooved cutting group, and the mean of NK and Alev measurements for the conventional classical cutting group. In our study, classical cutting results with the conventional method were found to be higher in all sections. Guide grooved cutting results were found to be significantly lower in all measurements except one of the sagittal section; Section 13/F1 (p