scholarly journals The Influence of Three Different Digital Cement Spacers on the Marginal Gap Adaptation of Zirconia-Reinforced Lithium Silicate Crowns Fabricated by CAD-CAM System

2021 ◽  
Vol 11 (22) ◽  
pp. 10709
Author(s):  
Gil Ben-Izhack ◽  
Asaf Shely ◽  
Sarit Naishlos ◽  
Ari Glikman ◽  
Liad Frishman ◽  
...  
Keyword(s):  
Regions Of Interest ◽  
Lithium Silicate ◽  
Marginal Gap ◽  
Cad Cam ◽  
Monolithic Zirconia ◽  
Bonferroni Test ◽  
Ceramic Crowns ◽  
Post Hoc ◽  
One Way Anova ◽  
Electronic Microscope

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.

scholarly journals (In-Vitro Comparison between Closed Versus Open CAD/CAM Systems) Comparison between Closed and Open CAD/CAM Systems by Evaluating the Marginal Fit of Zirconia-Reinforced Lithium Silicate Ceramic Crowns

2021 ◽  
Vol 11 (10) ◽  
pp. 4534
Author(s):  
Gil Ben-Izhack ◽  
Asaf Shely ◽  
Omer Koton ◽  
Avi Meirowitz ◽  
Shifra Levartovsky ◽  
...  
Keyword(s):  
Computer Aided Design ◽  
Open Systems ◽  
Lithium Silicate ◽  
Marginal Gap ◽  
Computer Aided ◽  
Cad Cam ◽  
Ceramic Crowns ◽  
Aided Design ◽  
Cam Systems

Background: This study compared the marginal gap (MG) and absolute marginal discrepancy (AMD) of computer-aided design and computer-aided manufacturing (CAD–CAM) used in open systems (OSs) and closed systems (CSs) for producing monolithic zirconia-reinforced lithium silicate (ZLS) ceramic crowns. Methods: 60 ZLS ceramic crowns were cemented to abutment acrylic teeth; thirty crowns were designed and milled by an OS, and thirty by a CS. All crowns were sectioned for evaluating the marginal gap by scanning electronic microscopy (SEM). To compare the marginal gap between CS and OS techniques, data were analyzed using the independent-samples Mann–Whitney U Test (α = 0.05). Results: AMD was found to be significantly better for the closed system (p < 0.05). Mean AMD values for the CS were 148 µm, and for the OS it was 196 µm. MG was found to be significantly better for the OS (p < 0.05). Mean MG values for the CS were 55 µm, and for the OS they were 38 µm. Conclusions: The marginal gap in relation to AMD was significantly better for CS. However, the marginal gap in relation to MG was significantly better for OS. Both techniques showed clinically acceptable MG values (<120 µm).

scholarly journals Marginal and Internal Fit of Ceramic Prostheses Fabricated from Different Chairside CAD/CAM Systems: An In Vitro Study

2021 ◽  
Vol 11 (2) ◽  
pp. 857
Author(s):  
Keunbada Son ◽  
Kyu-Bok Lee
Keyword(s):  
Computer Aided Design ◽  
In Vitro Study ◽  
Vitro Study ◽  
Marginal Gap ◽  
Significant Difference ◽  
Cad Cam ◽  
Ceramic Crowns ◽  
Internal Fit ◽  
Cam Systems

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.

scholarly journals Evaluation of Dual-Cure Resin Cement Polymerization under Different Types and Thicknesses of Monolithic Zirconia

2019 ◽  
Vol 2019 ◽  
pp. 1-9 ◽  
Author(s):  
Pinar Turkoglu ◽  
Deniz Sen
Keyword(s):  
Vickers Hardness ◽  
Resin Cement ◽  
Different Types ◽  
Monolithic Zirconia ◽  
Different Depths ◽  
Post Hoc ◽  
One Way Anova

Purpose. The aim of the present study was to investigate the effects of the type and thickness of the zirconia material on the microhardness of the underlying dual-cure resin cement. Materials and Methods. Eight disk-shaped zirconia specimens with a 4-mm diameter and four varying thicknesses (0.5, 1.0, 1.5, and 2.0 mm) were fabricated from two different monolithic zirconia materials: posterior monolithic zirconia (Prettau) and anterior monolithic zirconia (Prettau Anterior). Dual-cure resin cement specimens with a 4-mm diameter and 5-mm height were prepared using Teflon cylinder molds and activated by light beneath the eight zirconia disks and without any zirconia disk for 20 s (n=12). A total of 108 specimens were embedded in acrylic. Vickers hardness of each specimen was measured at three different depths using a microhardness device with a 50-g load. All data were statistically evaluated using three-way ANOVA, one-way ANOVA, independent samples t-tests, and Bonferroni corrected post hoc tests (α=.05). Results. Dual-cure resin cement’s microhardness was significantly higher for the samples polymerized beneath anterior monolithic zirconia compared to posterior monolithic zirconia. The hardness decreased as the thickness increased for both types of zirconia; the latter was attributed to an attenuated curing efficiency. Conclusion. Microhardness of the dual-cure resin cement is influenced by both the type and the thickness of the monolithic zirconia restoration. Polymerization efficiency for resin cement cured under anterior monolithic zirconia may be superior to cured beneath posterior monolithic zirconia.

Premolar Axial Wall Height Effect on CAD/CAM Crown Retention

2016 ◽  
Vol 41 (6) ◽  
pp. 666-671 ◽  
Author(s):  
C Gillette ◽  
R Buck ◽  
N DuVall ◽  
S Cushen ◽  
M Wajdowicz ◽  
...  
Keyword(s):  
Computer Aided Design ◽  
Lithium Disilicate ◽  
Resin Cement ◽  
Failure Resistance ◽  
All Ceramic ◽  
Computer Aided ◽  
Cad Cam ◽  
Ceramic Crowns ◽  
Aided Design ◽  
Post Hoc

SUMMARY Objective: To evaluate the significance of reduced axial wall height on retention of adhesively luted, all-ceramic, lithium disilicate premolar computer-aided design/computer-aided manufacturing (CAD/CAM) crowns based on preparations with a near ideal total occlusal convergence of 10°. Methods: Forty-eight recently extracted premolars were randomly divided into four groups (n=12). Each group received all-ceramic CAD/CAM crown preparations featuring axial wall heights of 0, 1, 2, and 3 mm, respectively, all with a 10° total occlusal convergence. Scanned preparations were fitted with lithium disilicate all-ceramic crowns that were luted with a self-etching resin cement. Specimens were tested to failure at a 45° angle to the tooth long axis with failure load converted to megapascals (MPa) based on the measured bonding surface area. Mean data were analyzed using analysis of variance/Tukey's post hoc test (α=0.05). Results: Lithium disilicate crowns adhesively luted on preparations with 0 axial wall height demonstrated significantly less failure resistance compared with the crowns luted on preparations with axial wall heights of 1 to 3 mm. There was no failure stress difference between preparations with 1 to 3 mm axial wall height. Conclusions: Under conditions of this study, adhesively luted lithium disilicate bicuspid crowns with a total occlusal convergence of 10° demonstrated similar failure resistance independent of axial wall height of 1 to 3 mm. This study provides some evidence that adhesion combined with an ideal total occlusal convergence may compensate for reduced axial wall height.

Comparison of Bond Strength of Monolithic CAD-CAM Materials to Resin Cement Using Different Surface Treatment Methods

2019 ◽  
Vol 10 (2) ◽  
pp. 120-127
Author(s):  
Sevki Cinar ◽  
Bike Altan ◽  
Gokhan Akgungor
Keyword(s):  
Bond Strength ◽  
Surface Treatment ◽  
Surface Treatments ◽  
Resin Cement ◽  
Lithium Silicate ◽  
Treatment Methods ◽  
Cad Cam ◽  
Post Hoc ◽  
Hybrid Ceramic ◽  
Silicate Ceramic

Objective: To compare the bond strength of monolithic CAD-CAM materials to resin cement using different surface treatment methods. Materials and Methods: Lithium disilicate glass ceramic (IPS e-max CAD), zirconia-reinforced lithium silicate ceramic (Vita Suprinity), resin nanoceramic (Lava Ultimate), and hybrid ceramic (Vita Enamic) were used. Five groups of CAD-CAM blocks were treated as follows: control (C), HF etching (HF), HF etching + silanization (HF + S), sandblasting (SB), and sandblasting + silanization (SB + S). After surface treatments, SEM analyses were conducted. Specimens were cemented with self-adhesive resin cement (Theracem) and stored in distilled water at 37°C for 24 h. Shear bond strength (SBS) was measured, and failure types were categorized. Results were analyzed using two-way ANOVA and the post-hoc Tukey test. Results: Statistical analysis revealed significant differences between SBS values obtained for different surface treatments and CAD-CAM block types ( P < .001). Among the CAD-CAM materials, the highest SBS was reported in the HF + S group for Vita Enamic. Although IPS e.max CAD, Vita Suprinity, and Vita Enamic showed higher bond strength when treated with HF + S, Lava Ultimate has the highest bond strength value when treated with SB + S. Conclusions: The bond strength of CAD-CAM materials was influenced by surface treatment. Additionally, silanization significantly improved the bond strength of all materials except Lava Ultimate.

scholarly journals Bulk-Fill Direct Restorative Materials: An In Vitro Assessment of Their Physio-Mechanical Properties

Oral ◽  
2021 ◽  
Vol 1 (2) ◽  
pp. 75-87
Author(s):  
Hui Woon Yeo ◽  
May Yeh Loo ◽  
Mariam Alkhabaz ◽  
Kai Chun Li ◽  
Joanne Jung Eun Choi ◽  
...  
Keyword(s):  
Flexural Strength ◽  
Wear Testing ◽  
Restorative Materials ◽  
Different Depths ◽  
Bonferroni Test ◽  
In Vitro Assessment ◽  
High Level ◽  
Post Hoc ◽  
One Way Anova

Bulk-fill restorative material has gained popularity in clinical practice, due to their perceived timesaving aspect. Objective was to compare the properties of bulk-fill direct restorative materials. Filtek Z350 (CR), Filtek One Bulk Fill Restorative (BF), Fuji IX and EQUIA Forte (EF) were compared. Thirty specimens from each material were prepared according to ISO 4049 for three-point flexural strength. Elastic moduli and hardness (n = 20) were evaluated using nanoindentation. Depth of cure (DC) (n = 20) was measured for BF at three different depths (2, 3, 4 mm) and at two irradiation times (20 and 40 s). Wear testing was carried out for three different periods (3, 6, 12 month(s)). All specimens were stored in 37 °C water for 24 h prior to testing. Results were evaluated using one-way ANOVA followed by a post hoc Bonferroni test (p < 0.05). BF and CR showed a significantly higher flexural strength than other groups (p < 0.05), and the highest Weibull modulus was found in CR. BF showed sufficient DC with at least 85%, at all thicknesses. CR and BF also had a high level of translucency than EF and Fuji IX. Significant differences in flexural strength were found among all materials except between Fuji IX and EF. While all material tested are suitable for use clinically, BF and CR have superior properties than GIC based bulk-fill.

scholarly journals In vitro evaluation of marginal fit of zirconia-reinforced lithium silicate laminate veneers at two thicknesses using different CAD/CAM systems

2020 ◽  
Vol 23 (4) ◽  
pp. 9p
Author(s):  
Manar Ahmed El-Mahdy ◽  
Ahmed Khaled Aboelfadl ◽  
Marwa Mohamed Wahsh
Keyword(s):  
In Vitro Study ◽  
Lithium Silicate ◽  
Milling Machine ◽  
Marginal Fit ◽  
Cad Cam ◽  
Marginal Discrepancy ◽  
Post Hoc ◽  
Laminate Veneers ◽  
Cam Systems

ABSTRACTObjective: The purpose of this in vitro study was to evaluate the marginal fit of laminate veneers made of zirconia-reinforced lithium silicate with two thicknesses using different CAD/CAM systems. Material and methods: 42 Laminate veneers milled from zirconia-reinforced lithium silicate were divided into three main groups according to milling machine used into: group X5, laminate veneers fabricated by inLab MCX5 milling machine; group CM, laminate veneers fabricated by Ceramill motion 2; and group XL, laminate veneers fabricated by inLab MCXL. Each group was divided into two subgroups according to veneer thickness into: subgroup I, 0.5 mm thickness laminate veneers and subgroup II, 0.3 mm thickness laminate veneers. The marginal fit was measured using stereomicroscope. The results were tabulated and statistically analyzed using two-way ANOVA test followed by Tukey’s post hoc test. Comparisons of main and simple effects were done utilizing Bonferroni correction (P ? 0.05). Results: The mean (±SD) highest marginal discrepancy was recorded in subgroup BII at 85.45±1.82 µm while the least mean marginal discrepancy was recorded in subgroup AI 71.24±2.64 µm. Conclusion: Both thicknesses (0.5 mm thickness and 0.3 mm thickness) and all tested CAD/CAM systems produced zirconia-reinforced lithium silicate laminate veneers with clinically acceptable marginal gaps; however, the closed CAD/CAM systems produced veneers with superior marginal fit than open systems at 0.3 mm thickness. The CAD/CAM system with the 5-axis milling machine produced the best marginal fit with 0.5 mm thickness. KEYWORDS Marginal fit; Zirconia-reinforced lithium silicate; Laminate veneers; CAD/CAM; Milling machines. RESUMOObjetivo: O objetivo deste estudo in vitro foi avaliar a adaptação marginal de facetas laminadas de silicato de lítio reforçado com zircônia com duas espessuras, utilizando diferentes sistemas CAD / CAM. Material e métodos: 42 facetas laminadas fresadas a partir de silicato de lítio reforçado com zircônia foram divididos em três grupos principais de acordo com a fresadora usada em: grupo X5, facetas laminadas fabricados pela fresadora inLab MCX5; grupo CM, facetas laminadas fabricados por Ceramill motion 2; e grupo XL, facetas laminadas fabricados pelo inLab MCXL. Cada grupo foi dividido em dois subgrupos, de acordo com a espessura do laminado, em: subgrupo I, facetas laminadas com 0,5 mm de espessura e subgrupo II, facetas laminadas com espessura de 0,3 mm. A adaptação marginal foi medida usando estereomicroscópio. Os resultados foram tabulados e analisados estatisticamente usando o teste ANOVA de dois fatores seguido pelo teste post hoc de Tukey. Comparações dos efeitos principais e simples foram realizadas utilizando a correção de Bonferroni (P ?0,05). Resultados: A maior discrepância marginal média (± DP) foi registrada no subgrupo BII em 85,45 ± 1,82 µm, enquanto a menor discrepância marginal média foi registrada no subgrupo AI 71,24 ± 2,64 µm. Conclusão: Ambas as espessuras (0,5 mm e 0,3 mm) e todos os sistemas CAD / CAM testados produziram facetas de laminado de silicato de lítio reforçadas com zircônia com lacunas clinicamente aceitáveis. No entanto, os sistemas CAD / CAM fechados produziam facetas com adaptação marginal superior aos sistemas abertos com 0,3 mm de espessura. O sistema CAD / CAM com a fresadora de 5 eixos produziu a melhor adaptação marginal com 0,5 mm de espessura.PALAVRAS-CHAVE Adaptação marginal; Silicato de lítio reforçado com zircônia; Facetas laminados; CAD / CAM; Fresadoras.

scholarly journals Comparison of Marginal and Internal Adaptation in Endocrowns Milled from Translucent Zirconia and Zirconium Lithium Silicate

2021 ◽  
Vol 2021 ◽  
pp. 1-9
Author(s):  
Amirhesam Amini ◽  
Somayeh Zeighami ◽  
Safoura Ghodsi
Keyword(s):  
Intraclass Correlation ◽  
Acrylic Resin ◽  
Lithium Silicate ◽  
Marginal Adaptation ◽  
Negative Effects ◽  
Marginal Gap ◽  
Replica Technique ◽  
Direct View ◽  
Cad Cam ◽  
Internal Adaptation

Purpose. This study aimed to compare marginal and internal adaptation in endocrowns made from translucent zirconia and zirconium lithium silicate using CAD-CAM technology. Materials and Methods. Twenty-eight freshly extracted upper molars were mounted in acrylic resin and underwent root canal therapy and endocrown preparation up to 2 mm above the cementoenamel junction. Endocrowns were CAD-CAM milled from zirconium lithium silicate (ZLS) and translucent zirconia (Zr). Internal and marginal adaptation was assessed by the replica technique before cementation. Marginal adaptation was evaluated by a stereomicroscope (×32) before and after cementation and also after thermomechanical aging. Results. The ZLS group showed significantly higher internal adaptation compared to the Zr group ( P  = 0.028), while the marginal adaptation differences, at different times with different methods, were not statistically significant ( P  > 0.05). Axiomarginal angle had the highest and axiopulpal angle showed the lowest adaptation in both groups. The cementation process and thermomechanical aging increased the marginal gap in both groups significantly ( P  < 0.001). The marginal gap assessed by the replica technique before cementation was 7.11 µm higher than direct view under a stereomicroscope with intraclass correlation coefficient of 0.797. Conclusion. Zirconia seems to be an acceptable material for endocrown with comparable internal and marginal adaptation to ZLS. Cementation and thermomechanical aging had significantly negative effects on marginal gap. The marginal gap assessed by the replica technique was higher than direct view under the stereomicroscope technique.

Sign in / Sign up

Export Citation Format

Share Document