Can Fiber Application Affect the Fracture Strength of Endodontically Treated Teeth Restored with a Low Viscosity Bulk-Fill Composite?

Objective. The aim of this study is to evaluate the effects of different fiber insertion techniques and thermomechanical aging on the fracture resistance of endodontically treated mandibular premolar teeth restored using bulk-fill composites. Materials and Methods. Eighty human mandibular premolar teeth were randomly divided into eight groups: Group IN, Group BF, Group PRF1, Group PRF2, Group IN-TMA, Group BF-TMA, Group PRF1-TMA ,and Group PRF2-TMA. Group IN (intact) and Group IN-TMA (intact but subjected to thermomechanical aging) served as control groups. In the other six groups, endodontic treatment was performed and standardized mesio-occluso-distal (MOD) cavities were prepared. In BF, PRF1, and PRF2, the cavities were restored with bulk-fill composite only, bulk-fill/Ribbond, and bulk-fill/additional Ribbond, respectively. In BF-TMA, PRF1-TMA, and PRF2-TMA, the teeth were subjected to thermomechanical aging after the restorations. All of the teeth were fractured on the universal testing machine. Fracture surfaces were analyzed with a stereomicroscope. Results. Control groups showed significantly higher fracture strengths than tested groups (P<0.05). No statistically significant difference was observed among the tested groups (P>0.05). Most of the favorable fractures were seen in PRF1, PRF2, and PRF2-TMA. Most of the unfavorable fractures were seen in BF-TMA. Conclusions. Although fiber insertion with different techniques did not increase the fracture strength of teeth restored with bulk-fill composites, it increased the favorable fracture modes. Thermomechanical aging did not change the fracture strength of the groups.

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Comparative Analysis of Fracture Strength of Remaining Tooth Structure after Endodontic Treatment with Various Access Cavity Preparation Techniques

The Open Dentistry Journal ◽

10.2174/1874210602014010681 ◽

2020 ◽

Vol 14 (1) ◽

pp. 681-686

Author(s):

Mohammed Mustafa ◽

Zaid A. AlJeaidi ◽

Ali Robaian AlQahtani ◽

Mohammed Ali Salem Abuelqomsan ◽

Raneem Suleiman Alofi ◽

...

Keyword(s):

Fracture Strength ◽

Fracture Resistance ◽

Statistical Tests ◽

Testing Machine ◽

Endodontic Treatment ◽

Cavity Preparation ◽

Endodontically Treated Teeth ◽

Tooth Structure ◽

Root Canals ◽

Significant Difference

Background: A perfect balance needs to be maintained between various types of endodontic access cavity preparation designs like - Traditional and conservative designed preparation to have access to the root canal system for proper cleaning and shaping of root canals without compromising the fracture resistance of the tooth structure. Aims and Objectives: We aimed to assess as well as draw comparisons of resistance against fracture of remaining tooth structure post the endodontic treatment after preparing access cavity through a variety of techniques so that we can estimate which type of cavity design technique will help endodontically treated teeth to withstand excessive load without fracture. Methods: Forty-two intact teeth (mandibular molars) were randomly selected and then were assigned to 07 different groups, inclusive of control and test groups. Various designs of access cavity preparation were done on sample teeth. The groups were divided based on different access cavity preparation designs as well as residual walls. The samples were then mounted on a composite cylinder, which was loaded under a mechanical testing machine at 0.5mm/min speed till the tooth structure fractured. This measurement of force was denoted in newton. The later analysis was carried out with the help of two-way Analysis of Variance (ANOVA) as well as Tukey’s post-hoc statistical tests. Results: There was negligible statistically relevant variance in strength towards fracture between traditional and conservative designs in teeth having three remaining walls. However, teeth with only two remaining walls fractured easily. Conclusion: Fracture resistance of teeth with remaining 03 residual walls did not show any significant difference among Traditional (TEC) and Conservative Cavity (CEC) design groups, but increased fracture strength was reported in CEC with 02 residual walls.

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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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Effect Of Accelerating Aging On Retention And The Release Period Of Clips In A Bar Retained Maxillary Implant Overdenture

Integrative Journal of Medical Sciences ◽

10.15342/ijms.2021.385 ◽

2021 ◽

Vol 8 ◽

Author(s):

Dalia El naggar ◽

Ahmed Mohamed Alam-Eldein ◽

Maha Mostafa Halim ◽

Hoda Mohammed Amin Rashad

Keyword(s):

Testing Machine ◽

Accelerated Aging ◽

The Other ◽

Universal Testing Machine ◽

Universal Testing ◽

Retention Loss ◽

Significant Difference ◽

Implant Overdenture

Objectives: This study was made to detect the effect of accelerating aging on retention and measuring the release period of clips in a 2 and 3 bar retained maxillary implant overdenture. Materials and Methods: Four implants were placed in two maxillary edentulous epoxy models. One model had two bar attachments with two clips overdenture while the other model had three bar attachments with three clips in the overdenture. Retention and release period of the clips were checked before applying insertion removal cycles. Retention was measured using universal testing machine after 540 cycles (6 months) and 1080 cycles (1 year) of insertion removal on a chewing simulator.Results and Conclusions: There was a significant difference in retention and release period between two bars and three bars implant retained maxillary overdentures. A significant difference was also seen in each group after accelerated aging. Therefore, the three bar implant retained overdenture had higher retention values than two bar. Retention loss occurred in both groups after the insertion removal cycles. Release period value was lower in two bar overdenture than three bar overdenture.

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Effect of post type on the fracture resistance of endodontically treated premolars

MATEC Web of Conferences ◽

10.1051/matecconf/201814504003 ◽

2018 ◽

Vol 145 ◽

pp. 04003

Author(s):

Ekaterina Karteva ◽

Neshka Manchorova ◽

Dessislava Pashkouleva ◽

Donka Keskinova ◽

Stoyan Vladimirov

Keyword(s):

Fracture Resistance ◽

Survival Rates ◽

Testing Machine ◽

Endodontically Treated Teeth ◽

Honestly Significant Difference ◽

Significant Difference ◽

Tukey Honestly Significant Difference ◽

Root Fractures ◽

Restoration Method ◽

Resistance Rates

Endodontically treated teeth (ETT) are more susceptible to fracture during mastication. The aim of our study was to investigate the fracture resistance of premolars, restored with different techniques. Eighteen human premolars, extracted for orthodontic or periodontal reasons, were used. Mesio-occlusal cavities were prepared on all of them. They were divided into 3 groups according to the restoration method: with a cemented fiber post (FP), with a cemented metal post (MP) and without a post, but restored with a fiber reinforced composite core (FRC). After thermocycling, their fracture resistance was evaluated in a standard testing machine. The results were analyzed with one-way ANOVA and Tukey Honestly Significant Difference (HSD) tests (p<0.05). The fracture modes were also determined. The MP group showed the lowest fracture resistance rates and the highest number of unrestorable root fractures. In conclusion, teeth restored with FRC cores or FP show better survival rates than those restored with metal posts.

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Tooth structure and fracture strength of cavities

Brazilian Dental Journal ◽

10.1590/s0103-64402007000200009 ◽

2007 ◽

Vol 18 (2) ◽

pp. 134-138 ◽

Cited By ~ 11

Author(s):

José Mondelli ◽

Fábio Sene ◽

Renata Pereira Ramos ◽

Ana Raquel Benetti

Keyword(s):

Mass Loss ◽

Fracture Strength ◽

Composite Resin ◽

Testing Machine ◽

Cavity Preparation ◽

Tooth Structure ◽

Universal Testing ◽

Significant Difference ◽

Before And After

This study evaluated, in vitro, the loss of tooth substance after cavity preparation for direct and indirect restorations and its relationship with fracture strength of the prepared teeth. Sixty sound human maxillary first premolars were assigned to 6 groups (n=10). MOD direct composite cavities (Groups I, II and III) and indirect inlay cavities (Groups IV, V and VI) were prepared maintaining standardized dimensions: 2-mm deep pulpal floors, 1.5-mm wide gingival walls and 2-mm high axial walls. Buccolingual width of the occlusal box was established at 1/4 (Groups I and IV), 1/3 (Groups II and V) or 1/2 (Groups III and VI) of the intercuspal distance. Teeth were weighed (digital balance accurate to 0.001 g) before and after preparation to record tooth substance mass lost during cavity preparation. The prepared teeth were submitted to occlusal loading to determine their fracture strength using a universal testing machine at a crosshead speed of 0.5 mm/min. Data were analyzed by two-way ANOVA and Tukey test (alpha= 0.05). 1/4-inlay cavities had higher percent mean mass loss (9.71%) than composite resin cavities with the same width (7.07%). 1/3-inlay preparations also produced higher percent mean mass loss (13.91%) than composite resin preparations with the same width (10.02%). 1/2-inlay cavities had 21.34% of mass loss versus 16.19% for the 1/2-composite resin cavities. Fracture strength means (in kgf) were: GI = 187.65; GII = 143.62; GIII = 74.10; GIV = 164.22; GV = 101.92; GVI = 50.35. Statistically significant difference (p<0.05) were observed between Groups I and IV, II and V, III and VI. Higher tooth structure loss and lower fracture strength were recorded after preparation of inlay cavities, regardless of the width of the occlusal box, compared to the direct composite resin cavities.

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Retention of provisional crowns cemented with eight temporary cements: comparative study

Journal of Applied Oral Science ◽

10.1590/s1678-77572004000300009 ◽

2004 ◽

Vol 12 (3) ◽

pp. 209-212 ◽

Cited By ~ 5

Author(s):

Mariana Ribeiro de Moraes Rego ◽

Luiz Carlos Santiago

Keyword(s):

Tensile Strength ◽

Comparative Study ◽

Testing Machine ◽

Strength Test ◽

The Other ◽

Universal Testing Machine ◽

Tensile Strength Test ◽

Universal Testing ◽

Significant Difference ◽

Crown Preparation

Many temporary cements are commercially available; therefore, it is necessary to indicate them for each clinical requirement with regard to the tensile strength of prosthetic retainers. Thus, the purpose of this study was to compare the retention of provisional crowns cemented with eight temporary cements, over full crown preparations with standardized mechanical principles as height, taper, and length. For that purpose, eighty human first premolars received full crown preparation with standardized height and taper. Provisional crowns were fabricated and luted with eight brands of temporary cements. Twenty four hours after cementation, the restorations were submitted to tensile strength test in a universal testing machine and the data submitted to ANOVA and Bonferroni tests. Mean tensile strength values ranged from 20.1N for Nogenol cement to 67.5N for Hydro C cement. Statistically significant difference (p<0.05) was found between Hydro C and the other groups, except for Temp Bond and Rely X Temp, which presented statistically significant difference when compared to Freegenol and Nogenol temporary cements. The crowns cemented with Hydro C cement were more retentive that than those cemented with the other cements, except for Rely X Temp and Temp Bond. The less retentive crowns were those cemented with Nogenol and Freegenol temporary cements.

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Effects of Denture Base Thicknesses and Reinforcement on Fracture Strength in Mandibular Implant Overdenture with Bar Attachment: Under Various Acrylic Resin Types

European Journal of Dentistry ◽

10.1055/s-0039-1688533 ◽

2019 ◽

Vol 13 (01) ◽

pp. 064-068

Author(s):

Selen Tokgoz ◽

Arda Ozdiler ◽

Burc Gencel ◽

Ergun Bozdag ◽

Gulbahar Isık-Ozkol

Keyword(s):

Fracture Strength ◽

Fracture Resistance ◽

Glass Fibers ◽

Testing Machine ◽

Acrylic Resin ◽

Base Thickness ◽

Denture Base ◽

Significant Difference ◽

Implant Overdenture ◽

Student’S T

Abstract Objective This study aimed to assess the effect of reinforcement, denture base thickness, and acrylic resin types on dynamic and static fracture strength in mandibular implant overdentures with bar attachment. Materials and Methods One hundred and eight experimental mandibular implant overdentures with bar attachments were fabricated in three main groups, namely unreinforced (control: C), reinforced with unidirectional glass fibers (FR), and Co–Cr cast metal (MR). Each group included denture bases of 2-, 3-, and 4-mm thicknesses and produced with conventional (CA) and high-impact acrylic (HIA) resins. Specimens were thermocycled (5,000 times, 5–55°C) then subjected to a 400,000 cyclic load regime. Unbroken specimens were then loaded until fracture by a universal testing machine. Differences in mean fracture resistance among the groups were compared using the one-way analysis of variance (with post hoc Tukey's honestly significant difference test) and Student's t-tests (α = 0.05). Results Fracture strength increased significantly when the denture base thickness was increased (p = 0.001). The 2-mm denture base thickness was not enough for reinforcement. The fracture strength of the FR groups was significantly higher than other groups for 3- and 4-mm thicknesses (p = 0.001). The fracture strength of the HIA resin was significantly higher than CA resin in FR groups (p = 0.029 and p = 0.001). MR groups showed the weakest fracture strength. Conclusions The 2-mm denture base thickness had sufficient fracture strength without reinforcement and a positive relationship between acrylic resin thickness and fracture resistance was found.

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Fracture Strength of Weakened Anterior Teeth Associated to Different Reconstructive Techniques

Brazilian Dental Journal ◽

10.1590/0103-6440201602452 ◽

2016 ◽

Vol 27 (5) ◽

pp. 556-561 ◽

Cited By ~ 1

Author(s):

Mariana Carolina de Lara Ferro ◽

◽

Vivian Colucci ◽

Artur Gaiotto Marques ◽

Ricardo Faria Ribeiro ◽

...

Keyword(s):

Fracture Strength ◽

Testing Machine ◽

Resin Cement ◽

Internal Wall ◽

Endodontically Treated Teeth ◽

Static Tests ◽

Chewing Simulation ◽

Anterior Teeth ◽

Significant Difference ◽

Reconstructive Techniques

Abstract This study evaluated the fracture strength of endodontically treated teeth submitted to reconstructive techniques through dynamic and static tests. Forty human anterior teeth were divided into 4 groups (n=10): GNW (non-weakened) - root restored with glass fiber post (GFP), GW - weakened root restored with GFP, GDA - weakened root restored with direct anatomic GFP, and GIA - weakened root restored with indirect anatomic GFP. The teeth were endodontically treated considering that experimental groups (GW, GDA and GIA) simulated weakened roots for restoration with GFP using different techniques. The GFP was luted with resin cement and the coronal portion was restored with composite resin and metallic crowns. All samples were submitted to chewing simulation at 60 cycles/min in a total of 300,000 cycles. The survival samples were further exposed to compressive loading at a crosshead speed of 1.0 mm/min in a universal testing machine. The load was applied at 135° to the long axis of the tooth until failure. Data were analyzed by ANOVA (a=0.05). After chewing simulation were observed: GNW: 100% of survival roots; GW: 70% of survival roots, and GDA and GIA: 80% of survival roots. The mean fracture strength values (N) were 280.6 (GNW), 239.0 (GW), 221.3 (GDA), and 234.1 (GIA) without significant difference among the groups (p=0.7476). The results suggested similar fracture strength in both weakened and non-weakened teeth regardless the reconstructive technique of root internal wall. Higher incidence of catastrophic fracture was observed in weakened teeth without restoration of the root internal wall.

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Fracture Strength of Ceramic Bracket Tie Wings Subjected to Force Direction

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.330-332.1353 ◽

2007 ◽

Vol 330-332 ◽

pp. 1353-1356

Author(s):

Kyoung Nam Kim ◽

Sang Bae Lee ◽

H.J. Kim ◽

J.S. Choi ◽

Kwang Mahn Kim ◽

...

Keyword(s):

Fracture Strength ◽

Testing Machine ◽

Compressive Force ◽

Test Device ◽

Steel Cylinder ◽

Paired Samples ◽

Universal Testing ◽

Significant Difference ◽

Force Direction ◽

Ceramic Bracket

In this study, the effects of bracket designs and force direction on fracture strength of alumina bracket were evaluated. Two differently designed alumina brackets (MISO, HT Co., Ltd., Seoul, Korea) were tested. Each bracket was bonded with orthodontic adhesive to stainless steel cylinder. Compressive force was applied to the tie wing of bracket at 30°, 60°, and 90° to the long axis of the test device. Fracture strengths were assessed by using a universal testing machine (Instron 3366, Instron Co., Ltd., U.S.A.). Fractured bracket surfaces were examined using SEM. Statistical analysis was performed by using SPSS 9.0 for Windows program. Paired samples t-tests and Kruskal-wallis tests were used at P<0.05. The fracture strength ranged from 150 N with the occlusal wing to 63 N with the cervical wing in bracket A. A significant difference was founded in fracture strength between the bracket designs and force directions. Based on this result, it could be concluded that bracket designs and force direction was important rule to improve fracture strength of ceramic bracket.

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Effects of intracanal medicaments and the remaining cavity wall on fracture strength of endodontically treated molars

Brazilian Dental Science ◽

10.14295/bds.2018.v21i1.1506 ◽

2018 ◽

Vol 21 (1) ◽

pp. 79

Author(s):

Keziban Olcay ◽

Ata Nisa Coban ◽

Sema Belli

Keyword(s):

Fracture Strength ◽

Testing Machine ◽

Cavity Wall ◽

Endodontically Treated Teeth ◽

Tooth Structure ◽

Significant Difference ◽

Maxillary Molar ◽

Univariate Anova ◽

Molar Teeth ◽

Post Hoc

Objective: The aim of this study was to investigate the effects of the short-term intracanal application of two medicaments on the fracture strength of root-filled molar teeth with different levels of tooth structure loss. Material and Methods: Standard access cavities of totally 84 intact maxillary molar teeth were prepared in 72 teeth and were divided into 3 main groups. Standard access cavities were kept in the first group, while mesio-occlusal-distal cavities (MOD) were prepared in the second and third groups. One-half of the palatinal walls were removed in the third group. Twelve sound teeth were used in the fourth group as control. Each group was then assigned into two subgroups according to the medicament used (n=12): 2% chlorhexidine gel and calcium hydroxide. Samples were stored at 37°C and 100% humidity for 1 week. Then the teeth were inserted into a universal testing machine and vertically loaded (5 mm/min) from the occlusal surface. The data was recorded in Newtons and statistically evaluated using a Univariate ANOVA and a Tukey as post hoc test. Results: A significant difference was found among the test groups (p<0.01). No significant difference was found according to the medicament used (p>0.05), however the number of remaining walls significantly affected the fracture strength (p<0.01). The first group with access cavity showed mostly repairable fractures (60%–80%) whereas the others showed mostly non-repairable fracture patterns (60%–90%). Conclusion: In conclusion, the fracture strength of endodontically treated teeth is related to the structure loss rather than the intracanal medicament used. KeywordsEndodontically treated teeth; Fracture strength; Intracanal medicament; Remaining cavity wall; Root facture.

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