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

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.

Folia Medica ◽  
2020 ◽  
Vol 62 (3) ◽  
pp. 546-552
Author(s):  
Aleksandra Pecheva ◽  
Kostadin Georgiev ◽  
Snezhana Tsanova ◽  
Ralitsa Raycheva

Introduction: One method to evaluate the clinical success of cemented restorations is measuring the marginal adaptation. There is a correlation between the fitting of the restoration and problems caused by clinically undetectable passage of bacteria between the tooth structure and the veneer. Aim: To evaluate in comparison the marginal adaptation of veneers produced via CAD/CAM and press technique. Materials and methods: 32 extracted incisors are divided into two equal-number groups (n=16) according to the production technique &ndash; CAD/CAM zirconium veneers and press-ceramic veneers. Cut sections are examined under a SEM magnification. Marginal accuracy is measured as the distance between the finish line of the tooth and the margin of the veneer at eight fixed locations. Results: The mean values of marginal gap of group 1 are: external adaptation &ndash; 79.88&plusmn;3.71 &micro;m; internal adaptation &ndash; 79.14&plusmn;15.70 &micro;m; cervical adaptation &ndash; 82.39&plusmn;28.55 &micro;m; incisal adaptation &ndash; 86.85&plusmn;21.72 &micro;m. The mean values of marginal gap of group 2 are: external adaptation &ndash; 100.31&plusmn;2.16 &micro;m; for internal adaptation &ndash; 101.01&plusmn;12.51 &micro;m; cervical adaptation &ndash; 91.55&plusmn;3.31 &micro;m; incisal adaptation &ndash; 93.76&plusmn;2.54 &micro;m. Conclusions: Veneers produced via CAD/CAM technology have better fit at the external and internal marginal wall. There is no statistically significant difference between the gaps at the cervical and the incisal areas.


Author(s):  
Abdulrahman Alhaddad ◽  
Samar Abuzinadah ◽  
Abdullah Al-Otaibi ◽  
Abrar Alotaibi ◽  
Mohsen Alfkih ◽  
...  

Background: Zirconia-based restorations have become more popular in dentistry during the last two decades. Patients choose metal-free restorations, preferring materials with similar attributes to natural teeth and similar light scattering characteristics, resulting in a nice esthetic appearance. Restoring a root canal treated teeth is one of the hot topics today. endo crown materials can be either; feldspathic, glass-ceramic, monolithic hybrid ceramic or composite material. Considering the marginal gap of endocrown, an important cause of failure of treatment, the current study evaluated the marginal gap of CAD‐CAM concocted endo-crowns. Materials and Methods: This research is an analysis systemic review study was conducted between January 2020 and October 2021. We followed the PRISMA principles and recorded this systematic review using the PROSPERO database to find and identify published literature related to the marginal adaptation of CAD-CAM-fabricated endocrown. The search will include all relevant articles through the end of 2021. Finally, 24 papers on marginal clearance and fracture resistance in coronary arteries were reviewed. Results: The electronic database search yielded 98 studies that were relevant. After cross-referencing, further seven studies were added. After a full-text analysis and duplicate reduction, 74 of the 98 articles were eliminated. 5 clinical (prospective) studies, 19 in vitro studies were found. Conclusion: This analysis of the recent literature on the marginal seating integrity and fracture resistance of CAD/CAM made-up endo-crowns showed that the endo-crown had superior marginal seating integrity than classical full crown. CAM/CAM showed statistically significant higher mean fracture resistance than MAD/MAM.


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.


2016 ◽  
Vol 41 (6) ◽  
pp. 607-616 ◽  
Author(s):  
MD Gaintantzopoulou ◽  
HM El-Damanhoury

SUMMARY The aim of the study was to evaluate the effect of preparation depth and intraradicular extension on the marginal and internal adaptation of computer-aided design/computer-assisted manufacture (CAD/CAM) endocrown restorations. Standardized preparations were made in resin endodontic tooth models (Nissin Dental), with an intracoronal preparation depth of 2 mm (group H2), with extra 1- (group H3) or 2-mm (group H4) intraradicular extensions in the root canals (n=12). Vita Enamic polymer-infiltrated ceramic-network material endocrowns were fabricated using the CEREC AC CAD/CAM system and were seated on the prepared teeth. Specimens were evaluated by microtomography. Horizontal and vertical tomographic sections were recorded and reconstructed by using the CTSkan software (TView v1.1, Skyscan).The surface/void volume (S/V) in the region of interest was calculated. Marginal gap (MG), absolute marginal discrepancy (MD), and internal marginal gap were measured at various measuring locations and calculated in microscale (μm). Marginal and internal discrepancy data (μm) were analyzed with nonparametric Kruskal-Wallis analysis of variance by ranks with Dunn's post hoc, whereas S/V data were analyzed by one-way analysis of variance and Bonferroni multiple comparisons (α=0.05). Significant differences were found in MG, MD, and internal gap width values between the groups, with H2 showing the lowest values from all groups. S/V calculations presented significant differences between H2 and the other two groups (H3 and H4) tested, with H2 again showing the lowest values. Increasing the intraradicular extension of endocrown restorations increased the marginal and internal gap of endocrown restorations.


2021 ◽  
Vol 11 (10) ◽  
pp. 4534
Author(s):  
Gil Ben-Izhack ◽  
Asaf Shely ◽  
Omer Koton ◽  
Avi Meirowitz ◽  
Shifra Levartovsky ◽  
...  

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).


2021 ◽  
Vol 10 (17) ◽  
pp. e162101724429
Author(s):  
Lucas José de Azevedo-Silva ◽  
Brunna Mota Ferrairo ◽  
Renato José Berro-Filho ◽  
Fernanda Ferruzzi Lima ◽  
José Henrique Rubo

Marginal and internal adaptation are parameters of crucial importance to the success of prosthetic crowns. Automatized process creates an expectative of superior or equivalent results compared to restorations manufactured ​​by conventional lost-wax technique. The purpose of this study was to evaluate the marginal adaptation and internal adaptation (cement space) of metal-ceramic crown copings produced by lost-wax (LW) and direct metal laser sintering (DMLS) techniques. An artificial lower first molar was prepared for a full crown, duplicated in plaster and scanned. Twenty metal-ceramic crown copings were fabricated in cobalt-chromium by the two techniques (n=10). The copings were filled with low viscosity silicone and seated on the prepared tooth, resulting in a replica of the internal space. The pellicle formed was embedded in heavy body silicone, sectioned and captured by means of a stereomicroscope at 50x magnification, according to replica technique (RT). Shapiro-Wilk test followed by Holm-Sidak test were used for statistical analysis (α=.05). Marginal adaptation presented no difference between LW (101.5 ± 41.6) and DMLS (86.3 ± 39.9) groups (p=0.24). Conventional LW technique showed significantly lower occlusal (p<0.008) and axial spaces (p<0.03).  Measurements of all regions showed numerically larger adaptation values than that defined during design​​ for DMLS group. Both the LW technique and the DMLS technique are within the clinically acceptable.


2018 ◽  
Vol 43 (5) ◽  
pp. 530-538 ◽  
Author(s):  
M Zimmermann ◽  
A Valcanaia ◽  
G Neiva ◽  
A Mehl ◽  
D Fasbinder

ABSTRACT Objective: CAM fabrication is an important step within the CAD/CAM process. The internal fit of restorations is influenced by the accuracy of the subtractive CAM procedure. Little is known about how CAM strategies might influence the fit of CAD/CAM fabricated restorations. The aim of this study was to three-dimensionally evaluate the fit of CAD/CAM fabricated zirconia-reinforced lithium silicate ceramic partial crowns fabricated with three different CAM strategies. The null hypothesis was that different CAM strategies did not influence the fitting accuracy of CAD/CAM fabricated zirconia-reinforced lithium silicate ceramic partial crowns. Methods and Materials: Preparation for a partial crown was performed on a maxillary right first molar on a typodont. A chairside CAD/CAM system with the intraoral scanning device CEREC Omnicam (Dentsply Sirona, York, PA, USA) and the 3+1 axis milling unit CEREC MCXL was used. There were three groups with different CAM strategies: step bur 12 (12), step bur 12S (12S), and two step-mode (12TWO). The zirconia-reinforced lithium silicate ceramic Celtra Duo (Dentsply Sirona) was used as the CAD/CAM material. A new 3D method for evaluating the fit was applied, consisting of the quadrant scan with the intraoral scanning device CEREC Omnicam. The scan of the PVS material adherent to the preparation and the preparation scan were matched, and the difference analysis was performed with special software OraCheck (Cyfex AG, Zurich, Switzerland). Three areas were selected for analysis: margin (MA), axial (AX), and occlusal (OC). Statistical analysis was performed using 80% percentile, one-way ANOVA, and the post hoc Scheffé test with α=0.05. Results: Statistically significant differences were found both within and between the test groups. The aspect axial fit results varied from 90.5 ± 20.1 μm for the two-step milling mode (12TWO_AX) to 122.8 ± 12.2 μm for the milling with step bur 12S (12S_AX). The worst result in all groups was found for the aspect occlusal fit with the highest value for group 12S of 222.8 ± 35.6 μm. Group two-step milling mode (12TWO) performed statistically significantly better from groups 12 and 12S for the occlusal fit (p&lt;0.05). Deviation patterns were visually analyzed with a color-coded scheme for each restoration. Conclusions: CAM strategy influenced the internal adaptation of zirconia-reinforced lithium silicate partial crowns fabricated with a chairside CAD/CAM system. Sensible selection of specific areas of internal adaptation and fit is an important factor for evaluating the CAM accuracy of CAD/CAM systems.


2018 ◽  
Vol 21 (3) ◽  
pp. 296
Author(s):  
Marília Pivetta Rippe ◽  
Elen Guerra ◽  
Arianne Vallim Pinto Coelho ◽  
Lilian Costa Anami ◽  
Renata Marques de Melo Marinho ◽  
...  

<p><strong>Objective:</strong> The aim of this study was to evaluate the internal and marginal adaptation of inlays fabricated from different types of impressions (conventional and digital) and different ceramics (feldspathic and lithium disilicate). <strong>Material and Methods:</strong> Forty premolars were prepared for all-ceramic inlay restoration and assigned to 4 groups (n=10), according to the impression method (conventional with addition silicone and digital impressions) and ceramic type (lithium disilicate and feldspathic ceramic blocks). For each type of impression, 10 inlays were fabricated from lithium disilicate blocks and the other 10 from feldspathic ceramic blocks, by means of the CAD-CAM system. The internal adaptation was analyzed by replica. The marginal fit was analyzed under a stereomicroscope by directly measuring the gap formed between the inlay and the tooth in the proximal and occlusal regions. <strong>Results:</strong> The marginal or internal adaptations were not affected by type of impression (conventional = digital impression), irrespective of the ceramic type. Only the internal adaptation was affected by material, i.e., feldspathic ceramic had lower values than disilicate ceramic, when considering the digital impression. <strong>Conclusion:</strong> The conventional and digital impressions promote similar marginal and internal adaptation of tested feldspathic and disilicate ceramic inlays. For digital impression the feldspathic ceramic showed better internal adaptation than lithium disilicate. </p><p><strong>Keywords</strong></p><p>Ceramics; Dental internal adaptation; Dental marginal adaptation; Dental impression technique.</p>


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