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

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.

Evaluation of marginal/internal fit of fixed dental prostheses after digital, conventional, and combination impression techniques: A systematic review

“…Furthermore, in an in vitro study performed by Svanborg et al [40], there was no statistically significant difference in marginal and internal fit values of cobalt-chromium alloy CAD/CAM crowns fabricated fully digitally or after scanning of a conventional cast. In contrast, Kim et al [9] reported that gold casted and palladium-silver alloy milled crowns fabricated after conventional impression making presented a significantly superior internal fit than crowns manufactured fully digitally or after digital impression and printing of the working cast. However, a clinical trial from Koulivand et al [42] resulted in a significantly lower marginal discrepancy for the digital group (TRIOS scanner) than conventionally manufactured cobalt-chromium alloy milled crowns.…”

“…Specifically, zirconia-, lithium disilicate-, and PFM/alloy-based restorations were investigated in terms of marginal discrepancy after digital vs. conventional impression making. In five of the selected articles, the investigators included protocols that tested more than one restorative material, that is, zirconia, lithium disilicate, or alloys [9][10][11][12][13].…”

Comparison of digital and silicone impressions for single-tooth implants and two- and three-unit implants for a free-end edentulous saddle

“…However, digital impressions using IOS have facilitated the designing of zirconia superstructures using CAD and machining using CAM [ 16 , 17 ], which have streamlined the process of prosthesis fabrication; thus, reducing the treatment time, laboratory time, and errors [ 8 , 18 ]. Several studies have reported on the performance of IOSs.…”

Assessment of marginal fit and the match of crowns made of various materials in the CAD/CAM technology to the abutment tooth

“…Kolejnym krokiem jest planowanie, projektowanie i realizacja leczenia protetycznego przez wykonanie uzupełnień protetycznych. 2,3 Innym zastosowaniem odwrotnej inżynierii może być kontrola wykonanych uzupełnień protetycznych przed ich zacementowaniem w jamie ustnej pacjenta. 4 Dzięki możliwości dokładnego skanowania zarówno modeli pacjenta, jak i powierzchni uzupełnienia protetycznego przy użyciu skanerów laboratoryjnych o wysokiej rozdzielczości, możliwe jest skontrolowanie parametrów dopasowania i szczelności brzeżnej uzupełnienia protetycznego bez…”

“…Wielu autorów podkreśla ich istotność z punktu widzenia prewencji powstawania próchnicy wtórnej pod uzupełnieniem, czy zapobieganiu odcementowaniu, a co za tym idzie, długoczasowej przeżywalności tego typu prac. 3,5 Z tego powodu, uznano właśnie te parametry, jako najważniejsze na początkowym etapie weryfikacji metodą inżynierii odwrotnej. W celu wykonania uzupełnień protetycznych, możliwe jest wykorzystanie wielu materiałów.…”