Clinical Acceptability of the Internal Gap of CAD/CAM PD-AG Crowns Using Intraoral Digital Impressions.

Tae-Gyung Kim,Sungtae Kim,Hyunmin Choi,Jae-Hoon Lee,Hong-Seok Moon,Jae-Hong Kim

doi:10.1155/2016/7065454

Abstract

The purpose of this study was to compare the internal gap between CAD/CAM palladium-silver crowns and cast gold crowns generated from intraoral digital versus conventional impressions and to determine the clinical acceptability. Nickel-chrome master dies were made from the prepared resin tooth with the conventional impression method (n = 40). For ICC (Intraoral, CAD/CAM) group, 10 intraoral digital impressions were made, and 10 CAD/CAM crowns of a PD-AG (palladium-silver) machinable alloy were generated. For IC (Intraoral, Cast) group, 10 gold crowns were cast from ten intraoral digital impressions. For CCC (Conventional, CAD/CAM) group, 10 CAD/CAM PD-AG crowns were made using the conventional impression method. For CC (Conventional, Cast) group, 10 gold crowns were fabricated from 10 conventional impressions. One hundred magnifications of the internal gaps of each crown were measured at 50 points with an optical microscope and these values were statistically analyzed using a two-way analysis of variance (α = 0.05). The internal gap of the intraoral digital impression group was significantly larger than in the conventional impression group (P < 0.05). No significant difference was observed between the CAD/CAM group and the cast group (P > 0.05). Within the limitations of this in vitro study, crowns from intraoral digital impressions showed larger internal gap values than crowns from conventional impressions.

Highlights

There are several problems with the conventional analog impression method, including high risk of crosscontamination and technical errors, requirements for several impression materials and laboratory processes, and patient’s discomfort [1, 2]
I-Tero is an independent digital impression device not connected to an in-office milling machine other than the CEREC and E4D intraoral digital impression devices [3]
The purpose of this study was to compare the internal gap between CAD/CAM Pd-Ag (Innovium) crowns and cast gold crowns generated from intraoral digital versus conventional impressions and to determine the clinical acceptability of the internal gap of CAD/CAM Pd-Ag (Innovium) crowns using intraoral digital impressions

Summary

Introduction

There are several problems with the conventional analog impression method, including high risk of crosscontamination and technical errors, requirements for several impression materials and laboratory processes, and patient’s discomfort [1, 2]. One of these is i-Tero digital impression device invented by Cadent in 2005 This electronic impression device scans dental arch and tooth structures while the patient is at chair-side using an oral scanner, with no impression material and tray and displays the 3-dimensional image on the LCD monitor and transmits it to the laboratory technician [2, 4, 5]. In this way, it provides the digital data necessary for fabricating accurate master models to a CAD/CAM machine [2]. I-Tero is an independent digital impression device not connected to an in-office milling machine other than the CEREC and E4D intraoral digital impression devices [3]

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Conclusion