Evaluation of Marginal and Internal Fit of A CAD/CAM Monolithic Zirconia‐Reinforced Lithium Silicate Porcelain Laminate Veneer System

2021 ◽  
Author(s):  
Mirza Rustum Baig ◽  
Aqdar A. Akbar ◽  
Mohammad Y Sabti ◽  
Zahra Behbehani
Materials ◽  
2021 ◽  
Vol 14 (21) ◽  
pp. 6346
Author(s):  
Haneen A. Sadeqi ◽  
Mirza Rustum Baig ◽  
Mohammad Al-Shammari

Fit accuracy and fracture strength of milled monolithic zirconia (Zi) and zirconia-reinforced lithium silicate (ZLS) crowns are important parameters determining the success of these restorations. This study aimed to evaluate and compare the marginal and internal fit of monolithic Zi and ZLS crowns, along with the fracture load, with and without mechanical aging. Thirty-two stone dies acquired from a customized master metal molar die were scanned, and ceramic crowns (16 Zi Ceramill Zolid HT+ and 16 ZLS Vita Suprinity) were designed and milled. Absolute marginal discrepancies (AMD), marginal gaps (MG), and internal gaps (IG) of the crowns, in relation to the master metal die, were evaluated using x-ray nanotomography (n = 16). Next, thirty-two metal dies were fabricated based on the master metal die, and crowns (16 Zi; 16 ZLS) cemented and divided into four groups of eight each; eight Zi with mechanical aging (MA), eight Zi without mechanical aging (WMA), eight ZLS (MA), and eight ZLS (WMA). Two groups of crowns (Zi-MA; ZLS-MA) were subjected to 500,000 mechanical cycles (200 ± 50 N, 10 Hz) followed by axial compressive strength testing of all crowns, until failure, and the values were recorded. Independent sample t tests (α = 0.05) revealed no significant differences between Zi and ZLS crowns (p > 0.05); for both internal and marginal gaps, however, there were significant differences in AMD (p < 0.005). Independent samples Mann–Whitney U and Kruskal–Wallis tests revealed significant differences between the two materials, Zi and ZLS, regardless of fatigue loading, and for the individual material groups based on aging (α = 0.05). Multiple comparisons using Bonferroni post-hoc analysis showed significant differences between Zi and ZLS material groups, with or without aging. Within the limitations of this study, the ZLS crown fit was found to be on par with Zi, except for the AMD parameter. As regards fracture resistance, both materials survived the normal range of masticatory forces, but the Zi crowns demonstrated greater resistance to fracture. The monolithic Zi and ZLS crowns seem suitable for clinical application, based on the fit and fracture strength values obtained.


Author(s):  
Zahra Khamverdi1 ◽  
Elmira Najafrad ◽  
Maryam Farhadian

Objectives: Marginal and internal fit of restorations are two important clinical factors for assessing the quality and durability of computer-aided design/computer-aided manufacturing (CAD/CAM)-fabricated monolithic zirconia restorations. The purpose of this study was to evaluate the marginal and internal fit of CAD/CAM zirconia crowns with two different scanners (i3D scanner and 3Shape D700). Materials and Methods: Twelve extracted sound human posterior teeth were prepared for full zirconia crowns. Two different extraoral scanners namely i3D scanner and 3Shape D700 were used to digitize type IV gypsum casts poured from impressions. The crowns were milled from presintered monolithic zirconia blocks by a 5-axis milling machine. The replica technique and MIP4 microscopic image analysis software were utilized to measure the marginal and internal fit by a stereomicroscope at ×40 magnification. The collected data were analyzed by paired t-test. Results: The mean marginal gap was 203.62 μm with 3Shape D700 scanner and 241.07 μm with i3D scanner. The mean internal gap was 192.30 μm with 3Shape D700 scanner and 196.06 μm with i3D scanner. The results of paired t-test indicated that there was a statistically significant difference between the two scanners in marginal fit (P=0.04); while, there was no statistically significant difference in internal fit (P=0.761). Conclusion: Within the limitations of this study, the results showed that type of extraoral scanner affected the marginal fit of CAD/CAM fabricated crowns; however, it did not have a significant effect on their internal fit.


Materials ◽  
2020 ◽  
Vol 13 (19) ◽  
pp. 4239
Author(s):  
Roxana-Diana Vasiliu ◽  
Sorin Daniel Porojan ◽  
Liliana Porojan

The accuracy of newly developed ceramic materials is still being studied. Marginal and internal adaptation are known factors that have an essential impact on the long term success of dental restorations. The aim of this in vitro study was to evaluate the marginal and internal fit of heat-pressed and milled monolithic glass-ceramic restorations based on their ceramic type, processing technique, and in vitro thermocycling. Thirty-two crowns were studied and divided into four groups (n = 8), according to the ceramic material (feldspathic glass-ceramic (F) and zirconia reinforced lithium silicate glass-ceramic (ZLS)) and to their technological obtaining processes (milling (M) and heat-pressing (P)). A typodont preparation was scanned with a D2000 3D scanner to obtain identical 32 resin 3D-printed abutment teeth. Marginal and internal gaps were measured using the silicone replica technique under 40× magnification. The crowns were further cemented and thermally aged for 10,000 cycles After cementation and thermocycling of the samples, marginal and internal gaps were assessed using micro-CT (micro-computed tomography)) analysis. Data were statistically analyzed using statistical tests. Significant differences were found before and after cementation and thermocycling among the tested materials (p < 0.05). Related to technological processing, significant differences were seen in the marginal area between FP and FM (p < 0.05) Significant differences were also found in the axial and occlusal areas between the ZLSP and ZLSM. Thermocycling and cementation did not have a significant effect on the tested materials (p < 0.05). The technological processes influenced the marginal and internal fit of the crowns in favor of the CAD/CAM (computer aided design/computer aided manufacturing)technologies. Thermal aging had little effect on marginal adaptability; it increased the values for all the tested samples in a small way, but the values remained in their clinically acceptable range for all of the crowns.


2021 ◽  
Vol 11 (22) ◽  
pp. 10709
Author(s):  
Gil Ben-Izhack ◽  
Asaf Shely ◽  
Sarit Naishlos ◽  
Ari Glikman ◽  
Liad Frishman ◽  
...  

Background: This study compared the influence of three different radial spacers (60,90,120 microns) on the marginal gap adaptation by using computer-aided manufacturing (CAD-CAM) for producing monolithic zirconia reinforced lithium silicate (ZLS) ceramic crowns. Methods: A total of 45 abutment acrylic teeth were divided into three groups of different radial spacers (60, 90, and 120 microns). In each group 15 teeth were scanned by Omnicam intra oral scanner and ZLS crowns were ground. For each unit the marginal gap was evaluated at four regions of interest by scanning electronic microscope (SEM). To compare the marginal gap between the three groups a one-way ANOVA with post-hoc Bonferroni test was preformed (α = 0.05). Results: The marginal gap for a 60 microns (162.99 ± 16.25 µm) radial spacer was found significantly higher than 90 (41.85 ± 3.57 µm) and 120 (41.85 ± 5.3 µm) microns radial spacers (p < 0.05). Between 90- and 120-micron radial spacers no difference was obtained. (p < 0.05). Conclusions: A radial spacer of 60 microns showed a significantly higher marginal gap compared to 90 and 120 microns and was not clinically accepted (>120 microns). For both 90 and 120 microns the marginal gap was clinically accepted (<120 microns) with no difference between the groups. The radial spacer which should be optimum for CELTRA® DUO crowns is 90 microns.


2020 ◽  
Vol 24 (1) ◽  
Author(s):  
Mosharraf Mosharraf ◽  
Amir Azizi ◽  
Babak Naziri ◽  
Majid Abolhasani

Objective: Studies demonstrated that as one of the newly developed restorative materials, monolithic zirconia resolved several issues of zirconia restoration. Therefore, marginal accuracy and internal fit are necessary for clinical success and quality of restorations, and cement space may influence the marginal fit. Thus, the present research aimed to investigate the effects of the cement thickness and kind of restoration on the marginal discrepancy. Material and methods: In this study, 20 maxillary left first molars, prepared by DRSK Co., were used to fabricate a full crown. Two types of material included monolithic zirconia (Zolid) and Sintron were used to make a full crown. Samples from each group were scanned by dental laboratory 3D scanner and designed and processed using CAD-CAM. The samples were divided into four groups of five with 30- and 50- µm cement spaces. In order to assess the vertical marginal discrepancy, the crowns were fitted on their respective teeth without using any mediator and examined by a micro-CT scanner. Data were analyzed by SPSS software. Results: It has been found that marginal discrepancy in Sintron is higher than the discrepancy of monolithic zirconia. In fact, monolithic zirconia with 50-micron cement space exhibited the least marginal discrepancy and the cement space in Sintron did not significantly influence the marginal discrepancy. Conclusion: It has been concluded that the material kinds and cement space influence the restoration marginal discrepancy constructed by digital workflow.  KEYWORDSDental cements; Dental marginal adaptation; X-Raymicrotomography.


2018 ◽  
Vol 19 (4) ◽  
pp. 230-233
Author(s):  
Adrian Mihai Varvară ◽  
◽  
Ralph Boutros ◽  
Anca Ştefania Mesaroş ◽  
Elena Bianca Varvară ◽  
...  

2021 ◽  
Vol 11 (2) ◽  
pp. 857
Author(s):  
Keunbada Son ◽  
Kyu-Bok Lee

The purpose of this in vitro study was to evaluate marginal and internal fits of ceramic crowns fabricated with chairside computer-aided design and manufacturing (CAD/CAM) systems. An experimental model based on ISO 12836:2015 was digitally scanned with different intraoral scanners (Omnicam (CEREC), EZIS PO (DDS), and CS3500 (Carestream)). Ceramic crowns were fabricated using the CAD/CAM process recommended by each system (CEREC, EZIS, and Carestream systems; N = 15). The 3-dimensional (3D) marginal and internal fit of each ceramic crown was measured using a 3D inspection software (Geomagic control X). Differences among the systems and various measurements were evaluated using the Kruskal–Wallis test. Statistically significant differences were validated using pairwise comparisons (α = 0.05). Occlusal gaps in the CEREC, EZIS, and Carestream groups were 113.0, 161.3, and 438.2 µm, respectively (p < 0.001). The axial gaps were 83.4, 78.0, and 107.9 µm, respectively. The marginal gaps were 77.8, 99.3, and 60.6 µm, respectively, and the whole gaps were 85.9, 107.3, and 214.0 µm, respectively. Significant differences were observed with the EZIS system compared with the other two systems in terms of the marginal gap sizes. The CEREC system showed no significant differences among the four measured regions. However, the EZIS and Carestream systems did show a statistically significant difference (p < 0.05). All three systems were judged to be capable of fabricating clinically acceptable prostheses, because the marginal gap, which is the most important factor in the marginal fit of prostheses, was recorded to be below 100 µm in all three systems.


2020 ◽  
Vol 75 (9) ◽  
pp. 505-510
Author(s):  
Veerasamy Yengopal

1. Prosthetic outcomes and clinical performance of CAD-CAM monolithic zirconia versus porcelain-fused-to-metal implant crowns in the molar region - 2. The effect of using a mobile application to improve oral hygiene among adolescents receiving fixed orthodontic treatment: A RCT


Author(s):  
Safoura Ghodsi ◽  
Sasan Raseipour ◽  
Mohammedreza Hajimahmoodi ◽  
Mohammad Mroue
Keyword(s):  
Cad Cam ◽  

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