Machining Accuracy of Crowns by CAD/CAM System Using TCP/IP: Influence of Restorative Material and Scanning Condition

Abstract

The purpose of this study was to determine the optimal condition for fabricating accurate crowns efficiently using an internet-based CAD/CAM system. The influences of three different CAD/CAM restorative materials (titanium, porcelain, and composite resin) and three different step-over scanning distances (0.01 mm, 0.11 mm, and 0.21 mm) were evaluated, and their interactive effects were carefully examined.Several points on the inner and outer surfaces of machined crowns -as well as height -were measured. These measurements were then compared with the original models, from which machining accuracy was obtained. At all measuring points, the inner surface of all crowns was machined larger than the die model, whereas the cervical area of porcelain crown was machined smaller than the crown model. Results of this study revealed that a step-over distance of 0.11 mm was an optimal scanning condition, taking into consideration the interactive effects of scanning time required, data volume, and machining accuracy.

A systematic review of CAD/CAM fit restoration evaluations

“…Following the electronic search of the two databases (Pubmed and Embase library), 230 articles were found. After reading the titles and abstracts, 140 papers were excluded from the study and 90 articles were selected for data analysis …”

The accuracy of the CAD system using intraoral and extraoral scanners for designing of fixed dental prostheses

“…Reference data for the master model were obtained using a coordinate measuring machine (E-DC-M400, Tokyo Seimitsu, Tokyo, Japan; CMM). Measurements were taken with a horizontal probe measurement load of 15 gf, and a vertical probe measuring load of 25 gf at an ambient operating temperature of 21.0±2.0°C 15) .…”

Dentistry 4.0 Concept in the Design and Manufacturing of Prosthetic Dental Restorations

“…To eliminate the lack of dimensional inaccuracy of manufactured prosthetic restorations, computer-aided design/computer-aided manufacturing CAD/CAM and full digitization of the manufacturing technologies [91,171,176,178,185,187,192,[349][350][351][352][353][354][355][356][357][358][359][360][361][362][363][364][365] are used. The manufacturing of metal foundations is increasingly used by machining with milling Co-Cr alloys, titanium alloys, as well as prefabricated ceramics, including oxides zirconia and alumina, and reinforced with lithium disilicate, as well as poly (methyl methacrylate) (PMMA) and wax.…”

“…An essential goal of using CAD technology in dental prosthetics is to increase the accuracy of the production process [349][350][351][352][353][354][355][356][357][358][359][360][361][362][363][364][365]370,[372][373][374][375][376][377]. One of the essential criteria for the long-term success of prosthetic restorations [378][379][380][381][382] is the highest possible compatibility of prosthetic restorations with the patient's anatomical features.…”