scholarly journals Fracture Resistance of Primary Zirconia Crowns: An In Vitro Study

Children ◽  
2022 ◽  
Vol 9 (1) ◽  
pp. 77
Author(s):  
AlWaleed Abushanan ◽  
Rajashekhara B. Sharanesha ◽  
Bader Aljuaid ◽  
Tariq Alfaifi ◽  
Abdullah Aldurayhim

In this study, we evaluated the fracture resistance of three commercially available prefabricated primary zirconia crowns and their correlation with dimensional variance. Methods: a total of 42 zirconia crowns were selected from three companies, (1) NuSmile primary zirconia crowns, (2) Cheng Crowns zirconia, and (3) Sprig EZ crowns. The crowns were divided into two groups based on their location in the oral cavity and further divided into subgroups based on the brand. All of the samples were subjected to fracture tests using a universal testing machine. Results: the mean load observed was highest with Cheng Crowns zirconia anterior crowns (1355 ± 484) and the least load was seen with Sprig EZ anterior crowns with a mean load of 339 ± 94. The mean load observed was highest with Cheng Crowns zirconia posterior crowns (1990 ± 485) followed by NuSmile posterior crowns and the least load was seen with Sprig EZ posterior crowns with a mean load of 661 ± 184. Conclusion: the Cheng crowns showed the highest fracture resistance amongst all three groups. Overall, the zirconia crowns (anterior and posterior) tested showed optimum mechanical properties to withstand the masticatory forces.

2021 ◽  
Vol 9 (10) ◽  
pp. 115
Author(s):  
Amirali Zandinejad ◽  
Marta Revilla-León ◽  
Mohammad Mujtaba Methani ◽  
Leila Nasiry Khanlar ◽  
Dean Morton

(1) Background: This study compared the fracture resistance of additively manufactured monolithic zirconia and bi-layered alumina toughened zirconia crowns on implants. (2) Methods: Maxillary model with a dental implant replacing right second bicuspid was obtained. Custom abutments and full-contour crowns for additively manufactured monolithic zirconia and bi-layered alumina reinforced zirconia crowns (n = 10) were fabricated. The crowns were cemented to implant-supported zirconia abutments and the assembly fixed onto resin blocks. Fracture resistance was measured using a universal testing machine at a crosshead speed of 2 mm/min. A Kruskal–Wallis test was used to analyze the data. (3) Results: Although additively manufactured monolithic zirconia crowns demonstrated a higher mean fracture resistance than bi-layered alumina toughened zirconia crowns, statistical analysis revealed no significant difference in fracture resistance between the two groups. All specimens fractured at the implant–abutment interface. (4) Conclusions: Additively manufactured bi-layered alumina toughened zirconia crowns demonstrated similar fracture resistance to additively manufactured monolithic zirconia crowns when cemented to implant-supported zirconia abutments.


2021 ◽  
Vol 24 (4) ◽  
Author(s):  
Ayman Sabbah ◽  
Mostafa Kamel

Objective: This study aimed to assess the fracture resistance of primary molars restored with endocrowns compared to prefabricated zirconia crowns. Methods: Twelve sound, defect-free primary second molars were selected and divided into two groups: group I included 6 molars restored with zirconia crowns, while group II included 6 teeth restored with endocrowns. For both groups access cavity was prepared for the teeth to open pulp chamber. Fracture resistance of both groups was tested using a universal testing machine. Results: Zirconia crown showed statistically significantly higher mean fracture resistance than Endocrown (P-value = 0.001, Effect size = 2.72). Conclusion: Pulpotomized primary molars restored with Zirconia crowns showed significantly higher mean fracture resistance compared to primary molars restored with endocrowns, meanwhile both restorations have shown higher mean fracture resistance than the maximum biting force in children. Keywords  Composite resins; Endocrown; Fracture strength; Zirconia crowns.


2016 ◽  
Vol 42 (6) ◽  
pp. 464-468 ◽  
Author(s):  
Anuya Patankar ◽  
Mohit Kheur ◽  
Supriya Kheur ◽  
Tabrez Lakha ◽  
Murtuza Burhanpurwala

This in vitro study evaluated the effect of different levels of preparation of an implant abutment on its fracture resistance. The study evaluated abutments that incorporated a platform switch (Myriad Plus Abutments, Morse Taper Connection) and Standard abutments (BioHorizons Standard Abutment, BioHorizons Inc). Each abutment was connected to an appropriate implant and mounted in a self-cured resin base. Based on the abutment preparation depths, 3 groups were created for each abutment type: as manufactured, abutment prepared 1 mm apical to the original margin, and abutment prepared 1.5 mm to the original margin. All the abutments were prepared in a standardized manner to incorporate a 0.5 mm chamfer margin uniformly. All the abutments were torqued to 30 Ncm on their respective implants. They were then subjected to loading until failure in a universal testing machine. Abutments with no preparation showed the maximum resistance to fracture for both groups. As the preparation depth increased, the fracture resistance decreased. The fracture resistance of implant abutment junction decreases as the preparation depth increases.


2020 ◽  
Vol 54 (2) ◽  
pp. 115-120
Author(s):  
Leyona Pushpa Femina I. ◽  
Chandrashekar B.S. ◽  
Arun A.V ◽  
Aravind S. Raju ◽  
Ramesh Kumar P.C. ◽  
...  

Objectives: The aim was to assess the mechanical properties of the three types of thermoplastic aligner materials before and after in vitro aging with carbonated drinks. Materials and methods: Twelve samples of thermoplastic aligner materials produced by three different manufacturers (Leone S.P.A, Florence, Italy; Duran, SCHEU-dental GmbH, Iserlohn, Germany; Essix ACE, Dentsply Raintree Essix, United States) were selected. Samples were thermoformed and later aged in vitro at a constant temperature in artificial saliva along with carbonated drinks (10 min each day) for 2 weeks. The mechanical properties were characterized using universal testing machine such as instron (MultiTest 10-i) and the results were compared with the control groups (before exposure to carbonated drinks). Results: All the above-mentioned thermoplastic materials tested showed an insignificant ( p > 0.05) decrease in stiffness, yield strength, and elastic modulus after aging. The stiffness of the thermoplastic materials increased with an increase in thickness. The flexure modulus was higher for the thinner materials, whereas it was lower for the thicker materials. Conclusion: Experimental results indicate that the aligner material will remain stable during and following exposure to carbonated drinks, which suggests that the orthodontic force from thermoplastic appliances does not decrease with clinical usage of carbonated drinks.


2019 ◽  
Vol 7 (23) ◽  
pp. 4089-4093
Author(s):  
Jyothi Bommanagoudar ◽  
Shashidhar Chandrashekhar ◽  
Shilpa Sharma ◽  
Hiten Jain

AIM: To evaluate and compare the effect of enamel preparation designs bevel, chamfer and stair-step chamfer on the fracture resistance of nanocomposite. METHODS: The sample group of this study consisted of 72 non-carious permanent maxillary central incisors. The sample is divided into four groups of 18 each. Group, I control Group II bevel preparation, Group III chamfer preparation, group IV stair step chamfer preparation. After the specific preparation, each tooth is filled with nanocomposite using bulk pack technique. The teeth were subjected to fracture resistance test under Universal testing machine and then were examined under a stereomicroscope to evaluate the type of bond failure. The results were subjected to statistical analysis. RESULTS: Results of the One-Way ANOVA revealed a significant difference in the mean peak failure load values of the four different groups. (P < 0.001) Tukey’s Post-Hoc comparison test revealed that there was a significant difference in the mean peak failure load values of the bevel and chamfer preparation. But there was no significant difference between chamfer and stair-step chamfer preparation designs. CONCLUSION: Stair-step chamfer preparation demonstrated comparable values to Chamfer preparation but also involved the removal of less amount of tooth structure adjacent to the fractured edge and good esthetic technique.


Polymers ◽  
2021 ◽  
Vol 13 (8) ◽  
pp. 1234
Author(s):  
António Sérgio Silva ◽  
Aurora Carvalho ◽  
Pedro Barreiros ◽  
Juliana de Sá ◽  
Carlos Aroso ◽  
...  

Thermal and self-curing acrylic resins are frequently and versatilely used in dental medicine since they are biocompatible, have no flavor or odor, have satisfactory thermal qualities and polishing capacity, and are easy and fast. Thus, given their widespread use, their fracture resistance behavior is especially important. In this research work, we comparatively analyzed the fracture resistance capacity of thermo and self-curing acrylic resins in vitro. Materials and Methods: Five prosthesis bases were created for each of the following acrylic resins: Lucitone®, ProBase®, and Megacryl®, which were submitted to different forces through the use of the CS® Dental Testing Machine, usually mobilized in the context of fatigue tests. To this end, a point was defined in the center of the anterior edge of the aforementioned acrylic resin bases, for which the peak tended until a fracture occurred. Thermosetting resins were, on average, more resistant to fracture than self-curable resins, although the difference was not statistically significant. The thermosetting resins of the Lucitone® and Probase® brands demonstrated behavior that was more resistant to fracture than the self-curing homologues, although the difference was not statistically significant. Thermosetting resins tended to be, on average, more resistant to fracture and exhibited the maximum values for impact strength, compressive strength, tensile strength, hardness, and dimensional accuracy than self-curing resins, regardless of brand.


2007 ◽  
Vol 21 (1) ◽  
pp. 51-57 ◽  
Author(s):  
Ana Cristina Soares Santos ◽  
André Tortamano ◽  
Sandra Regina Frazatto Naccarato ◽  
Gladys Cristina Dominguez-Rodriguez ◽  
Julio Wilson Vigorito

This in vitro study was designed to compare the forces generated by commercially available elastomeric chains and NiTi closed coil springs, and to determine their force decay pattern. Forty elastomeric chains and forty NiTi closed coil springs were divided into 4 groups according to the following manufacturers: (1) Morelli®, (2) Abzil®, (3) TP Orthodontics® and (4) American Orthodontics®. The specimens were extended to twice their original length and stored in artificial saliva at 37°C. Initial force was measured by means of an Instron universal testing machine and then at 1, 4, 7, 14, 21, and 28 days. The results revealed that the elastomeric chains delivered a mean initial force of 347 g for Morelli®, 351 g for American Orthodontics®, 402 g for Abzil®, and 404 g for TP Orthodontics®. The NiTi closed coil springs generated a mean initial force of 196 g for American Orthodontics®, 208 g for TP Orthodontics®, 216 g for Abzil®, and 223 g for Morelli®. The mean percentage of force decay observed after 28 days for the elastomeric chains was 37.4% for TP Orthodontics®, 48.1% for American Orthodontics®, 65.4% for Morelli®, and 71.6% for Abzil®. After 28 days, the NiTi closed coil springs presented a mean percentage of force decay of 22.6% for American Orthodontics®, 29.8% for Abzil®, 30.6% for Morelli®, and 45.8% for TP Orthodontics®. At the end of the study, significant differences were observed between the elastomeric chains and the NiTi closed coil springs. The results indicated that the studied NiTi closed coil springs are more adequate for dental movement than the elastomeric chains.


2015 ◽  
Vol 5 (1) ◽  
pp. 22-26
Author(s):  
Muzin Shahi Shaik ◽  
Snigdha Pattanaik ◽  
Sudhakar Pathuri ◽  
Arunachalam Sivakumar

Introduction: Bond strength is an important property and determines the amount of force delivered and treatment duration in orthodontics. Many light-cured bonding materials are being used; but it is required to determine the most efficient one withdesired bond strength. Objective: To determine and compare the shear bond strength of three visible light-cured composites (Transbond XT, Heliositand Enlight) and two self-cured composites (Rely-a-bond and Concise). Materials & Method: 100 extracted premolars were collected and randomly divided into 5 test groups of different adhesives. Brackets were bonded to the teeth in each test group with the respective adhesive according to the manufacturer’s instructions. Each specimen was debonded using Universal Testing Machine and the shear bond strength for each specimen was calculated. All the groups were compared by ANOVA one-way test. Results: There were statistically significant differences among the five groups (P<0.05). The shear bond strength of Enlight (13.92 ± 3.92) is similar to Transbond XT (14.30 ± 4.35). Conclusion: Light cure composites showed higher bond strength than self cure composites.


2019 ◽  
Vol 28 (8) ◽  
pp. 893-897 ◽  
Author(s):  
Amirali Zandinejad ◽  
Mohammad Mujtaba Methani ◽  
Emet D. Schneiderman ◽  
Marta Revilla‐León ◽  
Dean Morton BDS

2008 ◽  
Vol 9 (4) ◽  
pp. 17-25 ◽  
Author(s):  
Ilser Turkyilmaz ◽  
Suat Gokce ◽  
Emine Celik-Bagci

Abstract Aim The aim of this study was to investigate the influence of three different thicknesses of In-Ceram core on the load at fracture of all-ceramic crowns. Methods and Materials Thirty standardized crown-shaped nickel-chromium alloy dies were fabricated using a milling machine. Twenty dies were prepared with a 1 mm shoulder for Groups A and B. The only difference in the ten dies used for Group C was a smaller 0.5 mm lingual shoulder. The thicknesses of In-Ceram were 0.5 mm, 1.5 mm, and 0.75 mm for Groups A, B, and C. All all-ceramic crowns were fabricated in accordance with the manufacturer's instructions. After cementation of the crowns, their fracture resistance was tested with a universal testing machine. The load was directed to a point located 3 mm from the lingual aspect of the incisal edge at 30 degrees to the long axis of each specimen until catastrophic failure occurred. Results The mean loads at fracture for Groups A, B, and C were 1117±388 N, 2083±385 N, and 1439±368 N, respectively. No statistically significant difference in load at fracture between Groups A and C was found (p>0.05). However, the differences were statistically significant between Groups A and B (p<0.001) and Groups B and C (p<0.001). Conclusion Under the guidelines of this study, increasing the thickness of the In-Ceram core increased the fracture resistance of the all-ceramic crowns. Clinical Significance The sufficient thickness of the In-Ceram core of all-ceramic crowns is an important factor in fracture resistance. Therefore, dental practitioners should be careful in patient selection; if the horizontal overlap of a tooth to be restored is too limited, then all-ceramic crowns may not be a feasible option. Citation Gokce S, Celik-Bagci E, Turkyilmaz I. A Comparative in vitro Study of the Load at Fracture of Allceramic Crowns with Various Thicknesses of In-Ceram Core. J Contemp Dent Pract 2008 May; (9)4:017-025.


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