Effect of Finish Line Design on the Fit Accuracy of CAD/CAM Monolithic Polymer-Infiltrated Ceramic-Network Fixed Dental Prostheses: An In Vitro Study

Abstract

A polymer-infiltrated ceramic network (PICN) material has recently been introduced for dental use and evidence is developing regarding the fit accuracy of such crowns with different preparation designs. The aim of this in vitro study was to evaluate the precision of fit of machined monolithic PICN single crowns in comparison to lithium disilicate crowns in terms of marginal gap, internal gap, and absolute marginal discrepancies. A secondary aim was to assess the effect of finish line configuration on the fit accuracy of crowns made from the two materials. Two master metal dies were used to create forty stone dies, with twenty each for the two finish lines, shoulder and chamfer. The stone dies were scanned to produce virtual models, on which ceramic crowns were designed and milled, with ten each for the four material–finish line combinations (n = 10). Marginal gaps and absolute marginal discrepancies were evaluated at six pre-determined margin locations, and the internal gap was measured at 60 designated points using a stereomicroscope-based digital image analysis system. The influence of the material and finish line on the marginal and internal adaptation of crowns was assessed by analyzing the data using two-way analysis of variance (ANOVA), non-parametric, and Bonferroni multiple comparison post-hoc tests (α = 0.05). ANOVA revealed that the differences in the marginal gaps and the absolute marginal discrepancies between the two materials were significant (p < 0.05), but that those the finish line effect and the interaction were not significant (p > 0.05). Using the Mann–Whitney U test, the differences in IG for ‘material’ and ‘finish line’ were not found to be significant (p > 0.05). In conclusion, the finish line configuration did not seem to affect the marginal and internal adaptation of PICN and lithium disilicate crowns. The marginal gap of PICN crowns was below the clinically acceptable threshold of 120 µm.

The Effect of Preparation Design on the Marginal Adaptation of Monolithic Crowns Made of New CAD/CAM Ceramic Material An In-Vitro Study

“…In general, the values of the marginal gap of the three tested groups in this study were found to be within the previously mentioned accepted range of marginal discrepancies. (16,21,(31)(32)(33) The observed significantly lower marginal gap value in the Verti group can be attributed to the restoration margin ending with an acute angle, it results in a shorter distance between the tooth and the restoration margin. This phenomenon has been elucidated by Schillinburg et al (34) and Wahsh et al (31) Advanced lithium disilicate ceramic material was chosen in this study because it is a relatively innovative type of CAD/CAM material on the market that combines aesthetic and high strength benefits.…”

Porous Lithium Disilicate Glass–Ceramics Prepared by Cold Sintering Process Associated with Post-Annealing Technique

“…Lithium disilicate (Li 2 Si 2 O 5 , written as LD) glass–ceramics, the microstructure of which features interlocked rod-like LD crystals embedded in glass matrix [ 1 , 2 , 3 ], have gained much attention in prosthetic dentistry since 1998 [ 4 ]. In recent years, a novel restorative material, polymer-infiltrated-ceramic-network material (PICN), has gained researchers’ attention [ 5 , 6 , 7 ]. It features excellent mechanical properties [ 5 , 6 ] through interpenetrating polymers into porous ceramics.…”

“…In recent years, a novel restorative material, polymer-infiltrated-ceramic-network material (PICN), has gained researchers’ attention [ 5 , 6 , 7 ]. It features excellent mechanical properties [ 5 , 6 ] through interpenetrating polymers into porous ceramics. Until now, polymer-infiltrated porous feldspar ceramics [ 7 ], polymer-infiltrated porous zirconia ceramics [ 6 ], and other porous ceramics systems [ 5 , 8 ] have been successfully prepared.…”

“…It features excellent mechanical properties [ 5 , 6 ] through interpenetrating polymers into porous ceramics. Until now, polymer-infiltrated porous feldspar ceramics [ 7 ], polymer-infiltrated porous zirconia ceramics [ 6 ], and other porous ceramics systems [ 5 , 8 ] have been successfully prepared. However, there has not been a report regarding polymer-infiltrated porous LD glass–ceramics.…”

Effect of internal structures on the accuracy of 3D printed full-arch dentition preparation models in different printing systems

“…High-accuracy and high-stability casts guarantee the accuracy of prostheses and the credibility of experimental results. 21 22 Therefore, the research on model accuracy has always been a topic interest, even though the research object has been changing. Studies on the printing accuracy of full arch, 4 partial arch, 23 and implant restoration models, 24 and short unit preparations 25 26 have been relatively comprehensive, but there is a lack of research on the accuracy of 3D printed full-arch preparation models using different internal structures of models in different printing systems.…”