Fracture Resistance of Primary Molars Restored with Endocrowns Versus Zirconia Crowns (An in Vitro Study)

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.

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Comparison of the Effects of Three Different Nickel–titanium Rotary Instruments on the Fracture Resistance of Obturated Roots: An in vitro Study

Journal of Contemporary Dentistry ◽

10.5005/jp-journals-10031-1191 ◽

2017 ◽

Vol 7 (2) ◽

pp. 86-90

Author(s):

Vanitha U Shenoy ◽

Ritesh B Pawar ◽

Sumanthini MV ◽

Saimanaaz AH Shaikh

Keyword(s):

Fracture Resistance ◽

Testing Machine ◽

In Vitro Study ◽

Nickel Titanium ◽

Endodontically Treated Teeth ◽

Term Survival ◽

Group I ◽

Rotary Instruments ◽

Niti Instruments

ABSTRACT Aim The aim of the article is to compare the effects of three different nickel–titanium (NiTi) rotary instruments on the fracture resistance of obturated roots. Materials and methods A total of 100 permanent mandibular premolars were randomly divided into four groups of 25 teeth each and biomechanical preparation was done: group I: stainless steel K-hand files (HFs), group II: ProTaper NiTi instruments (PT), group III: HyFlex CM NiTi instruments (HCM), and group IV: K3XF NiTi instruments. Following root canal preparation, the canals were obturated using lateral condensation. A light body silicone impression material was used to simulate the periodontal ligament (PDL). Fracture resistance was tested in an Instron testing machine. Statistical analysis Data were analyzed with Kruskal–Wallis test. Results There was no difference in significance (p < 0.05) among the different groups tested with respect to their fracture resistances. Conclusion The present study concluded that rotary instrumentation could result in an increased chance for dentinal defects as compared with hand instrumentation. Greater taper rotary NiTi instruments do not increase the fracture susceptibility of roots, which in turn depends on various factors other than instrumentation alone. Clinical significance Greater taper achieved by rotary NiTi files during canal preparation facilitates efficient irrigation and complete debridement. Root fracture might occur as a result of microcracks or craze lines that propagate with repeated stress application by occlusal forces and also during canal preparation. Based on the results obtained, it can be decided whether the use of the newer rotary NiTi system contributes to endodontic success and long-term survival of endodontically treated teeth. How to cite this article Shaikh SAH, Shenoy VU, Sumanthini MV, Pawar RB. Comparison of the Effects of Three Different Nickel–titanium Rotary Instruments on the Fracture Resistance of Obturated Roots: An in vitro Study. J Contemp Dent 2017;7(2):86-90.

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Fracture Resistance of Primary Zirconia Crowns: An In Vitro Study

Children ◽

10.3390/children9010077 ◽

2022 ◽

Vol 9 (1) ◽

pp. 77

Author(s):

AlWaleed Abushanan ◽

Rajashekhara B. Sharanesha ◽

Bader Aljuaid ◽

Tariq Alfaifi ◽

Abdullah Aldurayhim

Keyword(s):

Mechanical Properties ◽

Oral Cavity ◽

Fracture Resistance ◽

Testing Machine ◽

In Vitro Study ◽

Universal Testing ◽

Zirconia Crowns ◽

Fracture Tests ◽

The Mean

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.

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COMPARISON OF THE FRACTURE RESISTANCE OF REATTACHED TOOTH FRAGMENT VERSUS COMPOSITE CORE BUILD-UP USING THREE DIFFERENT POST SYSTEMS IN ENDODONTICALLY TREATED ANTERIORS – AN IN VITRO STUDY.

International Journal of Medical and Biomedical Studies ◽

10.32553/ijmbs.v4i5.1147 ◽

2020 ◽

Vol 4 (5) ◽

Author(s):

Thendral S ◽

Rajesh Gopal V ◽

Benin Paulaian Paulaian ◽

Sudharsana S ◽

Jaikolden K

Keyword(s):

Fracture Strength ◽

Fracture Resistance ◽

Testing Machine ◽

In Vitro Study ◽

Positive Control ◽

Endodontically Treated Teeth ◽

Fracture Fragment ◽

Group I ◽

Group Ii

Objective: To compare the fracture resistance of endodontically treated teeth restored with Parapost, Everstick and Ribbond post systems. Materials and Methods: Root canal therapy was performed in 40 maxillary anteriors. The coronal portion of the teeth were sectioned at the junction of coronal and middle third of the crown and they were divided into four groups [n=10] .Group I served as a positive control. In group II, III and IV Parapost, Everstick and Ribbond were used respectively to restore the tooth. In group II the sectioned coronal fragment was reattached and in group III and IV core build up was done using composite. Specimens were loaded until failure in a universal testing machine and the resistance to fracture was calculated. Statistical Analysis: Datas were analysed using One Way ANOVA and Dunnett test. Results: Mean fracture resistance was as follows: Control – 393.0 N, Parapost – 238.0 N, Ribbond – 134.0 N, Everstick - 222N. The fracture strength of Parapost with reattached fracture fragment showed statistically significant fracture strength values when compared with Ribbond and Everstick where composite was used as a core build up material Keywords: Fracture resistance, Reattachment, Everstick, Ribbond, Parapost

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Effect of Hand and Rotary Instruments on the Fracture Resistance of Teeth: An In Vitro Study

Dentistry Journal ◽

10.3390/dj8020038 ◽

2020 ◽

Vol 8 (2) ◽

pp. 38

Author(s):

Nisha Acharya ◽

Md Riasat Hasan ◽

Dashrath Kafle ◽

Anil Chakradhar ◽

Takashi Saito

Keyword(s):

Fracture Resistance ◽

Testing Machine ◽

Compressive Load ◽

In Vitro Study ◽

Group Iv ◽

Group Iii ◽

Group I ◽

Significant Difference ◽

Group Ii

Objective: Endodontic treatment should be both conservative and effective. Endodontic instruments with a greater taper are used for coronal flaring, for proper debridement with efficient irrigation. However, increased taper of an instrument can remove a larger amount of pericervical dentin, compromising the strength of the tooth. The aim of this study was to determine the effect of hand files, ProTaper Universal, ProTaper Next, and V Taper rotary instrument systems on the fracture resistance of teeth. Materials and Methods: In total, 60 extracted human maxillary first premolars were divided into four groups—Group I (Hand Files; HF), Group II (ProTaper Universal; PT), group III (ProTaper Next; PTN) and Group IV (V Taper; VT) (N = 15). Each group was instrumented with the respective instrument system, irrigated, obturated, restored, and mounted in cold cure acrylic. A universal load-testing machine (Shimadzu, Japan) was used to apply a vertical compressive load. The maximum force was recorded in Newton. Analysis of variance (ANOVA) and Independent t-tests were applied to compare the maximum mean force required to fracture the tooth. Results: There was a statistically significant difference in fracture resistance between Group I (HF) and Group II (PT) and between Group II (PT) and Group IV (VT) (p < 0.001). Similarly, a significant difference was observed between Group II (PT) and Group III (PTN) (p < 0.01). Furthermore, a significant difference was observed between Group I (HF) and Group III (PTN), and between Group III (PTN) and Group IV (VT) (p < 0.05), too. However, there was no statistically significant difference between Group I (HF) and group IV (VT) (p > 0.05). Conclusion: Rotary files with more taper seem to remove more pericervical dentin than traditional manual and rotary files with less taper, thus altering the strength of the tooth.

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The Fracture Resistance of Additively Manufactured Monolithic Zirconia vs. Bi-Layered Alumina Toughened Zirconia Crowns When Cemented to Zirconia Abutments. Evaluating the Potential of 3D Printing of Ceramic Crowns: An In Vitro Study

Dentistry Journal ◽

10.3390/dj9100115 ◽

2021 ◽

Vol 9 (10) ◽

pp. 115

Author(s):

Amirali Zandinejad ◽

Marta Revilla-León ◽

Mohammad Mujtaba Methani ◽

Leila Nasiry Khanlar ◽

Dean Morton

Keyword(s):

Fracture Resistance ◽

Testing Machine ◽

In Vitro Study ◽

Universal Testing ◽

Significant Difference ◽

Implant Abutment ◽

Zirconia Crowns ◽

Monolithic Zirconia ◽

Ceramic Crowns

(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.

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Comparison of Enamel Preparations - Bevel, Chamfer and Stair Step Chamfer on Fracture Resistance of Nano Filled Resin Composites Using Bulk Pack Technique - An In Vitro Study

Open Access Macedonian Journal of Medical Sciences ◽

10.3889/oamjms.2019.853 ◽

2019 ◽

Vol 7 (23) ◽

pp. 4089-4093

Author(s):

Jyothi Bommanagoudar ◽

Shashidhar Chandrashekhar ◽

Shilpa Sharma ◽

Hiten Jain

Keyword(s):

Fracture Resistance ◽

Failure Load ◽

Testing Machine ◽

In Vitro Study ◽

Control Group ◽

Tooth Structure ◽

Group I ◽

Significant Difference ◽

The Mean

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.

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Comparison of Fracture Resistance in Thermal and Self-Curing Acrylic Resins—An In Vitro Study

Polymers ◽

10.3390/polym13081234 ◽

2021 ◽

Vol 13 (8) ◽

pp. 1234

Author(s):

António Sérgio Silva ◽

Aurora Carvalho ◽

Pedro Barreiros ◽

Juliana de Sá ◽

Carlos Aroso ◽

...

Keyword(s):

Fracture Resistance ◽

Research Work ◽

Testing Machine ◽

In Vitro Study ◽

Dimensional Accuracy ◽

Acrylic Resin ◽

Thermosetting Resins ◽

Acrylic Resins ◽

The Difference

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.

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Comparative Evaluation of Fracture Resistance of Endodontically Treated Teeth Restored with Resin Fiber Post and Stainless Steel Post: An In Vitro Study

Dental Journal of Advance Studies ◽

10.1055/s-0038-1672019 ◽

2015 ◽

Vol 03 (02) ◽

pp. 080-084

Author(s):

Vijay Singh ◽

Poonam Bogra ◽

Saurabh Gupta ◽

Navneet Kukreja ◽

Neha Gupta

Keyword(s):

Stainless Steel ◽

Fracture Resistance ◽

Testing Machine ◽

Compressive Force ◽

Control Group ◽

Fiber Post ◽

Endodontically Treated Teeth ◽

Group I ◽

Significant Difference

AbstractFracture resistance of endodontically treated teeth restored with post. Aims: This study aims to compare the fracture resistance of endodontically treated teeth restored with resin fiber and stainless steel post. Commercially available prefabricated resin fiber post(Dentsply Maillefer Easy Post), prefabricated stainless steel post(Coltene/Whaledent Parapost) were used. Methods and Material: Forty five maxillary central incisors were obturated and divided into 3 groups: Control Group (Group I) without any post (n = 15), Resin Fiber Post Group (Group II) (n = 15) and Stainless Steel Post Group (Group III) (n = 15). In all Groups except control group, post space was prepared; a post was cemented, and a core build-up was provided. All the specimens were subjected to compressive force under a universal testing machine until fracture. Statistical analysis used: The results were analyzed using the variable analysis test (ANOVA). Results: One-way analysis of variance revealed significant difference among test groups. The control group demonstrated highest fracture resistance (925.2183 N), followed by the resin fiber post group (486.7265 N) and stainless steel post group (423.539N). Conclusions: Teeth restored with resin fiber post showed higher fracture resistance values than prefabricated stainless steel post.

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“Ormocer an innovative technology”: A replacement for conventional cements and veneer? A comparative in vitro analysis

European Journal of Dentistry ◽

10.4103/ejd.ejd_113_16 ◽

2017 ◽

Vol 11 (01) ◽

pp. 058-063 ◽

Cited By ~ 1

Author(s):

Vini Rajeev ◽

Rajeev Arunachalam ◽

Sanjna Nayar ◽

P. R. Arunima ◽

Sivadas Ganapathy ◽

...

Keyword(s):

Bond Strength ◽

Testing Machine ◽

In Vitro Study ◽

Sem Analysis ◽

Innovative Technology ◽

Group I ◽

Luting Cement ◽

Significant Difference ◽

Vitro Analysis

ABSTRACT Objective: This in vitro study was designed to assess shear bond strength (SBS) of ormocer flowable (OF) resin as a luting agent, ormocer as an indirect veneer material with portrayal of modes of failures using scanning electron microscope (SEM). Materials and Methods: Sixty maxillary central incisors were divided into Group I, II, and III with 20 samples each based on luting cement used. They were OF, self-adhesive (SA) cement, and total etch (TE) cement. These groups were subdivided into “a” and “b” of ten each based on the type of veneering materials used. Veneer discs were fabricated using Ormocer restorative (O) and pressable ceramic (C). Specimens were thermocycled and loaded under universal testing machine for SBS. The statistical analysis was done using one-way ANOVA post hoc Tukey honest significant difference method. Results: A significant difference was observed between the Groups I and II (P < 0.05). The highest mean bond strength when using ormocer veneer was obtained with the Group Ia (19.11 ± 1.92 Mpa) and lowest by Group IIa (8.1 ± 1.04 Mpa), whereas the highest mean bond strength while using ceramic veneer was of similar range for Group Ib (18.04 ± 4.08 Mpa) and Group IIIb (18.07 ± 1.40 Mpa). SEM analysis revealed OF and TE presented mixed type of failure when compared with SA where failure mode was totally adhesive. Conclusion: OF was found equally efficient like TE. Bond strength of ormocer as a veneer was not inferior to ceramic making it one of the promising additions in the field of dentistry.

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