Fracture Resistance of Computer Aided Endocrowns versus Conventional Core-Supported Computer Aided Full Crowns = Résistance aux Fractures des Endo-Couronnes Assistées par Ordinateur par Rapport aux Couronnes Conventionnelles Assistées par Ordinateur

2019 ◽  
Vol 10 (2) ◽  
pp. 54-59
Author(s):  
Rayyan , Mohammad M. ◽  
Hussien , Ahmed Naguib ◽  
Naguib , Hanan ◽  
Makarem , Hiba
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.


Materials ◽  
2019 ◽  
Vol 12 (10) ◽  
pp. 1623 ◽  
Author(s):  
Ting-Hsun Lan ◽  
Chin-Yun Pan ◽  
Pao-Hsin Liu ◽  
Mitch M. C. Chou

The aim of this study is to determine the minimum required thickness of a monolithic zirconia crown in the mandibular posterior area for patients with bruxism. Forty-nine full zirconia crowns, with seven different occlusal thicknesses of 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, and 1.0 mm, were made by using a computer-aided design/computer-aided manufacturing system (CAD/CAM). Seven crowns in each group were subjected to cyclic loading at 800 N and 5 Hz in a servohydraulic testing machine until fracture or completion of 100,000 cycles. Seven finite element models comprising seven different occlusal thicknesses of 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, and 1.0 mm were simulated using three different loads of vertical 800 N, oblique 10 degrees 800 N, and vertical 800 N + x N torque (x = 10, 50, and 100). The results of cyclic loading tests showed that the fracture resistance of the crown was positively associated with thickness. Specimen breakage differed significantly according to the different thicknesses of the prostheses (p < 0.01). Lowest von Mises stress values were determined for prostheses with a minimal thickness of 1.0 mm in different loading directions and with different forces. Zirconia specimens of 1.0 mm thickness had the lowest stress values and high fracture resistance and under 800 N of loading.


2015 ◽  
Vol 40 (2) ◽  
pp. 201-210 ◽  
Author(s):  
HM El-Damanhoury ◽  
RN Haj-Ali ◽  
JA Platt

SUMMARY This study assessed marginal leakage and fracture resistance of computer-aided design/computer-aided manufacturing (CAD/CAM) fabricated ceramic crowns with intracoronal extensions into the pulp chambers of endodontically treated teeth (endocrowns) using either feldspathic porcelain (CEREC Blocks [CB], Sirona Dental Systems GmbH, Bensheim, Germany), lithium disilicate (e.max [EX], Ivoclar Vivadent, Schaan, Liechtenstein), or resin nanoceramic (Lava Ultimate [LU], 3M ESPE, St Paul, MN, USA).). Thirty extracted human permanent maxillary molars were endodontically treated. Standardized preparations were done with 2-mm intracoronal extensions of the endocrowns into the pulp chamber. Teeth were divided into three groups (n=10); each group was restored with standardized CAD/CAM fabricated endocrowns using one of the three tested materials. After cementation with resin cement, specimens were stored in distilled water at 37°C for one week, subjected to thermocycling, and immersed in a 5% methylene-blue dye solution for 24 hours. A compressive load was applied at 35 degrees to long axis of the teeth using a universal testing machine until failure. Failure load was recorded, and specimens were examined under a stereomicroscope for modes of failure and microleakage. Results were analyzed using one-way analysis of variance and Bonferroni post hoc multiple comparison tests (α=0.05). LU showed significantly (p&lt;0.05) higher fracture resistance and more favorable fracture mode (ie, fracture of the endocrown without fracture of tooth) as well as higher dye penetration than CB and EX. In conclusion, although using resin nanoceramic blocks for fabrication of endocrowns may result in better fracture resistance and a more favorable fracture mode than other investigated ceramic blocks, more microleakage may be expected with this material.


2019 ◽  
Vol 8 (11) ◽  
pp. 1932 ◽  
Author(s):  
Amesti-Garaizabal ◽  
Agustín-Panadero ◽  
Verdejo-Solá ◽  
Fons-Font ◽  
Fernández-Estevan ◽  
...  

Background: The aim of this systematic review and meta-analysis was to determine the fracture resistance and survival rate of partial indirect restorations inlays, onlays, and overlays fabricated using computer-aided design and computer-aided manufacturing (CAD-CAM) technology from ceramics, composite resin, resin nanoceramic, or hybrid ceramic and to analyze the influence of proximal box elevation on fracture resistance. Materials and methods: This systematic review was based on guidelines proposed by the preferred reporting items for systematic reviews and meta-analyses (PRISMA). An electronic search was conducted in databases US National Library of Medicine National Institutes of Health (PubMed), Scopus, Web of Science (WOS), and Embase. In vitro trials published during the last 10 years were included in the review. Results: Applying inclusion criteria based on the review’s population, intervention, comparison, outcome (PICO) question, 13 articles were selected. Meta-analysis by restoration type estimated the fracture resistance of inlays to be 1923.45 Newtons (N); of onlays 1644 N and of overlays 1383.6 N. Meta-analysis by restoration material obtained an estimated fracture resistance for ceramic of 1529.5 N, for composite resin of 1600 Ne, for resin nanoceramic 2478.7 N, and hybrid ceramic 2108 N. Conclusions: Resin nanoceramic inlays present significantly higher fracture resistance values. Proximal box elevation does not exert any influence on the fracture resistance of indirect restorations.


Medicina ◽  
2020 ◽  
Vol 56 (3) ◽  
pp. 132
Author(s):  
Georgina García-Engra ◽  
Lucia Fernandez-Estevan ◽  
Javier Casas-Terrón ◽  
Antonio Fons-Font ◽  
Pablo Castelo-Baz ◽  
...  

Background and Objectives: To evaluate in vitro the fracture resistance and fracture type of computer-aided design and computer-aided manufacturing (CAD-CAM) materials. Materials and Methods: Discs were fabricated (10 × 1.5 mm) from four test groups (N = 80; N = 20 per group): lithium disilicate (LDS) group (control group): IPS e.max CAD®; zirconium-reinforced lithium silicate (ZRLS) group: VITA SUPRINITY®; polymer-infiltrated ceramic networks (PICN) group: VITA ENAMIC®; resin nanoceramics (RNC) group: LAVA™ ULTIMATE. Each disc was cemented (following the manufacturers’ instructions) onto previously prepared molar dentin. Samples underwent until fracture using a Shimadzu® test machine. The stress suffered by each material was calculated with the Hertzian model, and its behavior was analyzed using the Weibull modulus. Data were analyzed with ANOVA parametric statistical tests. Results: The LDS group obtained higher fracture resistance (4588.6 MPa), followed by the ZRLS group (4476.3 MPa) and PICN group (4014.2 MPa) without statistically significant differences (p < 0.05). Hybrid materials presented lower strength than ceramic materials, the RNC group obtaining the lowest values (3110 MPa) with significant difference (p < 0.001). Groups PICN and RNC showed greater occlusal wear on the restoration surface prior to star-shaped fracture on the surface, while other materials presented radial fracture patterns. Conclusion: The strength of CAD-CAM materials depended on their composition, lithium disilicate being stronger than hybrid materials.


Materials ◽  
2021 ◽  
Vol 14 (20) ◽  
pp. 6199
Author(s):  
Naoko Suzaki ◽  
Satoshi Yamaguchi ◽  
Eriko Nambu ◽  
Ryousuke Tanaka ◽  
Satoshi Imazato ◽  
...  

The prevention of root fractures of pulpless teeth is an important clinical issue to maintain healthy teeth through lifetime. The aim of this study was to examine a clinically effective treatment method for strengthening vulnerable pulpless teeth using CAD/CAM (computer-aided design/computer-aided manufacturing) fiber-reinforced post-core by conducting a fracture resistance test. A post-core made with a fiber-reinforced resin disk TRINIA (TR, SHOFU, Kyoto, Japan) was fabricated using a CAD/CAM system. The fiber-layer orientation of the CAD/CAM post-core was parallel to the axis of the restored tooth. A post-core using a conventional composite and a fiber post (CF) was also prepared. A fracture resistance test of teeth restored with the post-cores and zirconia crowns was conducted using a universal testing machine, and fracture patterns were identified by micro-CT observation. The fracture load of the roots restored with TR was 1555.9 ± 231.8 N, whereas that of CF was 1082.1 ± 226.7 N. The fracture load of TR was 43.8% that was significantly higher than that of CF (Student’s t-test, p < 0.05). The restored teeth with CAD/CAM resin post-core were found to be repairable even after fracture. These results suggest that the CAD/CAM indirect fiber post-core has the potential to strengthen the vulnerable pulpless teeth.


2017 ◽  
Vol 42 (3) ◽  
pp. 327-334 ◽  
Author(s):  
A Hayes ◽  
N Duvall ◽  
M Wajdowicz ◽  
H Roberts

SUMMARY Purpose: The purpose of this study was to evaluate the effect of endocrown pulp chamber extension on mandibular molar fracture resistance. Methods and Materials: A total of 36 recently extracted mandibular third molars of approximate equal size were sectioned at the facial lingual height of contour followed by endodontic access into the pulp chamber. The specimens were then randomly divided into three groups (n=12) and pulpal and root canal contents removed. Pulp chamber floors were established at 2, 3, and 4 mm from the occlusal table using a three-step etch-and-rinse adhesive and a flowable resin composite. The prepared specimens were then embedded in auto-polymerizing denture base resin with surface area available for adhesive bonding determined using a digital recording microscope. Specimens were restored using a standardized template with a chairside computer-aided design/computer-aided manufacturing unit with the endocrown milled from a lithium disilicate glass–ceramic material. Restoration parameters of occlusal table anatomy and thickness were standardized with the only parameter difference being the pulp chamber extension depth. The endocrown restorations were luted with a self-adhesive resin luting agent and tested to failure after 24 hours on a universal testing machine, with force applied to the facial cusps at a 45° angle to the long axis of the tooth. The failure load was converted into stress for each specimen using the available surface area for bonding. Mean failure load and stress among the three groups was first subjected to the Shapiro-Wilk and Bartlett tests and then analyzed with an analysis of variance with the Tukey post hoc test at a 95% confidence level (p=0.05). Results: The 2- and 4-mm chamber extension groups demonstrated the highest fracture resistance stress, with the 3-mm group similar to the 2-mm group. The 3- and 4-mm chamber extension group specimens demonstrated nearly universal catastrophic tooth fracture, whereas half the 2-mm chamber extension group displayed nonrestorable root fractures. Conclusions: Under the conditions of this study, mandibular molars restored with the endocrown technique with 2- and 4-mm pulp chamber extensions displayed greater tooth fracture resistance force as well as stress. All groups demonstrated a high number of catastrophic fractures, but these results may not be clinically significant because the fracture force results are higher than normal reported values of masticatory function.


2015 ◽  
Vol 123 (2) ◽  
pp. 122-129 ◽  
Author(s):  
Akio Harada ◽  
Keisuke Nakamura ◽  
Taro Kanno ◽  
Ryoichi Inagaki ◽  
Ulf Örtengren ◽  
...  

2019 ◽  
Vol 44 (3) ◽  
pp. 312-321 ◽  
Author(s):  
C Papadopoulos ◽  
D Dionysopoulos ◽  
K Tolidis ◽  
P Kouros ◽  
E Koliniotou-Koumpia ◽  
...  

SUMMARY Aims: To evaluate the effect of two composite restorative techniques (direct bulk fill vs indirect CAD/CAM) on the fracture resistance and mode of fracture of extended mesio-occlusal-distal (MOD) cavity preparations. Methods: Fifty-one sound human mandibular third molars were divided into three groups (n=17). Extended bucco-lingual MOD cavities were prepared. Teeth in group 1 were restored with a bulk-fill resin composite (Filtek Bulk-Fill Posterior Restorative), teeth in group 2 were restored with composite computer-aided design/computer-aided manufacturing (CAD/CAM) inlays (Lava Ultimate), and teeth in group 3 served as control and remained intact. All specimens were submitted to thermocycling, and a fracture resistance test was performed using a Universal testing machine (0.5 mm/min). Mode of fracture was classified into five types. One-way analysis of variance and the Duncan test were used to analyze the fracture load data at a significance level of α = 0.05. A chi-square test was used for the analysis of fracture mode between the restorative groups. Results: Statistical analysis showed significant differences in fracture resistance among the experimental groups. The teeth restored with the bulk-fill composite exhibited lower fracture resistance (1285.3±655.0 N) when compared to the teeth restored with the composite CAD/CAM inlays (1869.8±529.4 N) (p&lt;0.05). Mode of fracture showed the same distribution between the restorative groups. Conclusions: Although both types of restorations failed at loads larger than those found in the oral cavity, the CAD/CAM composite inlays increased the fracture resistance of teeth with large MOD cavities when compared to direct bulk-fill composite restorations. The majority of fracture types were intraorally repairable for both restorative techniques.


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