scholarly journals In Vitro Fatigue and Fracture Load of Monolithic Ceramic Crowns Supported by Hybrid Abutment

2021 ◽  
Vol 15 (1) ◽  
pp. 664-671
Author(s):  
Noor Nawafleh ◽  
Shareen Elshiyab ◽  
Andreas Öchsner ◽  
Roy George
Keyword(s):  
Clinical Performance ◽  
Testing Machine ◽  
Lithium Disilicate ◽  
Fracture Load ◽  
Control Group ◽  
Supporting Structure ◽  
Significant Difference ◽  
Fatigue And Fracture ◽  
N Loading

Objective: This study evaluated the performance of zirconia and lithium disilicate crowns supported by implants or cemented to epoxy resin dies. Methods: Eigthy zirconia and lithium disilicate crowns each were prepared and assigned in four groups according to the crown material and supporting structure combinations (implant-supported zirconia, die-supported zirconia, implant-supported lithium disilicate, and die-supported lithium disilicate). Ten crowns in each group acted as control while the rest (n=10) underwent thermocycling and fatigue with 100 N loading force for 1.5 million cycles. Specimens were then loaded to fracture in a universal testing machine. Data were analysed using one-way ANOVA and Tukey multiple comparison test with a 95% level of significance. Results: No implants or crown failure occurred during fatigue. The mean fracture load values (control, fatigued) in newton were as follows: (4054, 3344) for implant-supported zirconia, (3783, 3477) for die-supported zirconia, (2506, 2207) for implant-supported lithium disilicate, and (2159, 1806) for die-supported lithium disilicate. Comparing the control with the corresponding fatigued subgroup showed a significantly higher fracture load mean of the control group in all cases. Zirconia showed a significantly higher fracture load mean than lithium disilicate (P=0.001, P<0.001). However, comparing crowns made from the same material according to the supporting structure showed no significant difference (P=0.923, P=0.337). Conclusion: Zirconia and lithium disilicate posterior crowns have adequate fatigue and fracture resistance required for posterior crowns. However, when heavy fatigue forces are expected, zirconia material is preferable over lithium disilicate. Zirconia and lithium disilicate implant-supported crowns cemented to hybrid abutments should have satisfactory clinical performance.

scholarly journals Evaluation of fracture resistance of Cerasmart and lithium disilicate ceramic veneers with different incisal preparation designs: an in vitro study

F1000Research ◽  
2019 ◽  
Vol 8 ◽  
pp. 1491 ◽  
Author(s):  
Bushra Mohammed ◽  
Jylan EL-Guindy
Keyword(s):  
Hybrid Material ◽  
Fracture Resistance ◽  
Testing Machine ◽  
In Vitro Study ◽  
Lithium Disilicate ◽  
Fracture Load ◽  
Significant Difference ◽  
Preparation Design ◽  
Laminate Veneers

Background: Cerasmart hybrid material offers specific advantages such as less fragility and more flexibility than glass ceramics. This material also has the option of readily modifying or repairing the surface and favorable stress-absorbing characteristics. In our study, Cerasmart hybrid and lithium disilicate ceramic laminate veneers with two different preparation designs were compared with regards to their fracture resistance. Methods: A total of 52 of comparable human central maxillary incisors were used. Group A (n=26) was made up of Cerasmart hybrid ceramic laminate veneers were fabricated from Cerasmart blocks, while Group B (n=26) was made up of lithium disilicate ceramic laminate veneers were made of IPS e.max pressable ingots. Each group was subdivided in two equal subgroups according to preparation designs. Subgroup I comprised Featheredge preparation design and subgroup II: Wraparound preparation design. All samples were subjected to thermocycling between 5°C and 55°C in a water bath for a total of 1750 cycle with 10 seconds dwell time at each bath. The fracture load strength test was performed using a universal testing machine. Results: There was no statistically significant difference between all groups. E.max wraparound group recorded the highest fracture resistance mean value (422.1 N) followed by Cerasmart wraparound group (317.23 N), then e.max featheredge group (289.6 N), and finally Cerasmart featheredge group (259.3 N) had the lowest value as analyzed by one-way ANOVA. Conclusions: The Cerasmart hybrid material could be considered as a valid alternative to the widely used IPS e.max material. The fracture resistance of laminate veneers is not influenced by different type of preparation designs.

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

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.

Influence of Different Restoration Techniques on Fracture Resistance of Root-filled Teeth: In Vitro Investigation

2018 ◽  
Vol 43 (2) ◽  
pp. 162-169 ◽  
Author(s):  
ME Hshad ◽  
EE Dalkılıç ◽  
GC Ozturk ◽  
I Dogruer ◽  
F Koray
Keyword(s):  
Fracture Strength ◽  
Resin Composite ◽  
Testing Machine ◽  
Compressive Force ◽  
Control Group ◽  
Hybrid Resin ◽  
Flowable Composite ◽  
In Vitro Investigation ◽  
Significant Difference

SUMMARY Objective: The purpose of this study was to determine the fracture strength of endodontically treated mandibular premolar teeth restored with composites and different reinforcement techniques. Methods and Materials: Forty-eight freshly extracted human mandibular premolar teeth were randomly divided into four groups: group IN, group CR, group FRC, and group PRF. Group IN consisted of teeth with intact crowns and served as the control group. In the other three groups, endodontic treatment was performed and standard mesio-occluso-distal (MOD) cavities were prepared. Then cavities were restored with hybrid resin composite only, flowable composite and hybrid resin composite, and Ribbond, flowable composite and hybrid resin composite in groups CR, FRC and PRF, respectively. All of the teeth were subjected to fracture by means of a universal testing machine, and compressive force was applied with a modified stainless-steel ball at a crosshead speed at 0.5 mm/min. Results: The highest values were observed in group IN, while the lowest values were determined in group CR. There was not any statistically significant difference between group CR and group FCR (p&gt;0.05). When groups CR, FCR, and PRF were compared, group PRF showed significantly better fracture strength than did groups CR and FCR (p&lt;0.05). It was determined that there was not any significant difference between group IN and group PRF (p&gt;0.05). Conclusions: Polyethylene ribbon fiber considerably increases the fracture strength of mandibular premolar teeth with MOD cavities restored with composite.

Comparison of the Initial Repeated Bond Strength among Three Orthodontic Bonding Systems

2014 ◽  
Vol 1025-1026 ◽  
pp. 385-390
Author(s):  
Niwat Anuwongnukroh ◽  
Surachai Dechkunakorn ◽  
Jirawat Arunakol ◽  
Wassana Wichai
Keyword(s):  
Bond Strength ◽  
Shear Bond Strength ◽  
Tooth Movement ◽  
Testing Machine ◽  
Control Group ◽  
Instron Testing Machine ◽  
Significant Difference ◽  
Bonding Systems ◽  
Experimental Group

One of the problems that often occurred during orthodontic treatment is bracket failure. This is usually the result either of the patient’s accidentally, applying inappropriate forces to the bracket or of a poor bonding technique. Thus, a significant number of teeth have to be rebonded in an orthodontic practice. Objective: The aim of this study was to evaluate the in vitro initial repeated shear bond strength of the three adhesive systems at two and five minutes after placement of a bracket. Materials and Methods: The three bonding agent adhesives are System1+, Rely-a-bond, Unite. Two hundred and forty human premolar teeth were divided into two groups, a control and an experimental group. Each group was further divided into three subgroups for bonding brackets with the three different adhesives. Only the teeth in the experimental group were sequentially bonded and debonded two times with the same adhesive. The teeth in control and experimental groups were tested for shear bond strength (at two and five minutes after the bracket was bonded) with an Instron testing machine. Results: The studies were found that : (1) there were differences between the shear bond strength of each adhesive in the control and experimental group. Unite had the highest shear bond strength followed by Rely-a-bond and System1+ at two minutes and five minutes, (2) the experiment group ( rebonded brackets) had higher shear bond strength than control group and Unite had in significant difference (p<0.05) of initial repeated bond strength with System1+ and Rely-a-bond at two minutes and five minutes and (3) there were mostly significant difference (p<0.05) between repeated shear bond strength at two minutes and repeated shear bond strength at five minutes. Conclusion: There were significant difference of the initial repeated shear bond strength of each adhesive. The orthodontists should be aware of applying force for tooth movement into the repeated bonding brackets.

scholarly journals Evaluation and Comparison of Two Different Mouthwashes on Frictional Resistance Between Orthodontic Bracket and Archwire: An in Vitro Study

2019 ◽  
Vol 53 (2) ◽  
pp. 117-125
Author(s):  
Jayanti Choudhary ◽  
B Shashikumar ◽  
Anand K Patil
Keyword(s):  
Stainless Steel ◽  
Artificial Saliva ◽  
Steel Wire ◽  
Testing Machine ◽  
Frictional Resistance ◽  
Control Group ◽  
Tea Tree ◽  
Custom Made ◽  
Significant Difference

Aims: This study aimed to evaluate and compare the effect of tea tree oil (TTO) mouthwash and chlorhexidine (CHX) mouthwash on frictional resistance. Settings and Design: In vitro. Materials and Methods: In total, 60 extracted premolars were mounted on a custom-made acrylic fixture. These 60 premolars were randomly divided into 3 groups of 20 each, on which 0.022″ × 0.028″ slot MBT stainless steel brackets were bonded and 0.019″ × 0.025″ rectangular stainless steel wire was ligated with an elastomeric module. The 3 groups included a control group where the samples were immersed in artificial saliva and 2 experimental groups immersed in 0.2% CHX and TTO mouthwash, respectively, for 1.5 hours. Postimmersion static frictional resistance was evaluated on a universal testing machine at crosshead speed of 0.5 mm/min. Statistical Analysis Used: Tukey’s post hoc procedure. Results: This study showed a statistically significant difference in the frictional resistance between saliva and CHX groups and CHX and TTO groups ( P < .05). No statistically significant difference was observed between saliva and TTO groups ( P > .05). The frictional resistance was more in the CHX mouthwash group than in the TTO mouthwash group. Conclusions: Frictional resistance was lesser in the TTO mouthwash than in the CHX mouthwash. Based on this result, TTO mouthwash can be used instead of CHX mouthwash as an oral hygiene aid in patients with orthodontic treatments.

scholarly journals Effect of MTA versus CEM apical plugs on fracture resistance of endodontically treated simulated immature teeth restored with cast metal posts: an in-vitro study

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Ensieh Grayli ◽  
Abbas Dashtban ◽  
Leyla Shadan ◽  
Naser Behnampour ◽  
Elham Afshari
Keyword(s):  
Fracture Resistance ◽  
Testing Machine ◽  
In Vitro Study ◽  
Control Group ◽  
Significance Level ◽  
Cast Metal ◽  
Immature Teeth ◽  
Gutta Percha ◽  
Significant Difference

Abstract Background Endodontically treated immature teeth which are restored with cast metal posts are of the most susceptible teeth to fracture. An apical plug is usually used as root end filling in order to seal the wide apical foramen. The current study was performed to evaluate the effect of different apical plug materials (MTA and Calcium enriched mixture cement) at varied thicknesses on fracture resistance of teeth restored with cast metal posts. Methods A total of 40 extracted intact single-rooted human mandibular premolars (removed for orthodontic reasons) were used in the study. The coronal part of each tooth was removed and root canal preparation was performed. A size 4 Gates Glidden drill was used to enlarge the canal and was passed through the apical foramen in order to simulate an immature apex. Samples were randomly divided into 5 groups (n = 8) according to apical plug (control group: No plug, group MTA5: 5 mm MTA plug, group CEM5: 5 mm CEM plug, group MTA3: 3 mm MTA plug, group CEM3: 3 mm CEM plug). Post-space preparations were performed and cast metal post-and-cores were fabricated and cemented. Fracture resistance was assessed using a universal testing machine. Fracture thresholds were recorded and data were analyzed using One-way ANOVA and Dunnett’s T3 tests with significance level at P value < 0.05. Results The analysis showed a significant difference of fracture resistance between groups (P value < 0.05). The mean fracture resistance of samples in control group was significantly lower than MTA5 (P value = 0.003). There was no significant difference between other groups (P value > 0.05). Conclusions Within the limits of this study, the evidence indicated that placement of a 5 mm MTA apical plug increased the fracture resistance in simulated immature teeth which are restored with cast metal posts, compared to control group (gutta-percha and sealer). While the results were not as promising for a 3 mm MTA apical plug or either 3 or 5 mm CEM apical plug.

scholarly journals Comparative analysis of flexural strength of abraded and polished porcelain surfaces – an in vitro study

2021 ◽  
Vol 14 (1) ◽  
pp. 61-67
Author(s):  
Prathibha Nandagiri ◽  
◽  
Mamidi Praveen ◽  
Shikha Singh ◽  
Monika Singh ◽  
...  
Keyword(s):  
Flexural Strength ◽  
Testing Machine ◽  
The Other ◽  
Control Group ◽  
P Value ◽  
Diamond Bur ◽  
Significant Difference ◽  
Fine Diamond ◽  
Ceramic Restorations

Typically, prosthodontists adjust ceramic restorations glazed surface by grinding prior to insertion. Such alterations of surfaces are necessary for the correction of occlusal interferences. We aimed to evaluate and compare the change in flexural strength of ceramic surfaces after re-glazing and polishing. This study included 40 samples of ceramic blocks that were fabricated and glazed, and then fired in accordance with the manufacturer’s recommendations. The sample was randomly divided into four groups of 10 samples each. The first group was the control group with unaltered glazed samples. The second group was abraded with an extra-fine diamond bur followed by re-glazing, and the other two groups were polished with two commercially available polishing kits after abrading them with an extra-fine diamond bur. The samples were tested for their flexural strength using a universal testing machine. On the application of the F test on the means of all the groups, a value greater than 0.05 was found, which meant that there is no statistically significant difference in flexural strength values between the groups (P-value>0.05). Since the flexural strength values of the polished group were comparable to the other groups, polishing can be used instead of re-glazing for ceramic restorations. This reduces an additional clinical appointment for the patient and saves working time.

scholarly journals Effect of Different Time Periods of Vital Bleaching on Flexural Strength of Bovine Enamel and Dentin Complex

2007 ◽  
Vol 8 (3) ◽  
pp. 21-28 ◽  
Author(s):  
Marjaneh Ghavamnasiri ◽  
Sara Abedini LNU ◽  
Alireza Mahdizadeh Tazangi
Keyword(s):  
Flexural Strength ◽  
Artificial Saliva ◽  
Testing Machine ◽  
Control Group ◽  
Mean Values ◽  
Significant Difference ◽  
Time Periods ◽  
Group 2 ◽  
Bovine Enamel

Abstract Aim The aim of this in vitro study was to evaluate the effect of 20% carbamide peroxide (CP) on the flexural strength (FS) of bovine enamel and dentin complex. Methods and Materials One hundred sound bovine teeth were selected for use. Blocks (2×3×8 mm) from the middle portion of the facial surfaces of each crown were sectioned from the teeth. The specimens were randomly divided into five groups (n=20) based on the time period of vital bleaching. Group 1 comprised the control group kept in artificial saliva. The experimental groups subjected to immersion in 20% CP, Opalescence, for four, six and eight weeks, respectively (eight hours daily). Mechanical testing was performed 24 hours after the last treatment using an Instron Universal Testing Machine with a crosshead speed of 0.5 mm/min. The results were analyzed by one-way analysis of variance (ANOVA) and Tukey's test (α=0.05). Results Mean values for FS were 141.27, 103.06, 120.71, 130.23, and 117.90 (Mpa), respectively. Statistically significant differences in FS were noted among the groups. A statistically significant difference was observed between Group 2 (two week bleach) and the control. Conclusion Application of 20% CP bleach for two weeks provided significant decreases in FS of bovine enamel and dentin complex. Similar decreases were not observed among the other groups. Citation Ghavamnasiri M, Abedini S, Tazangi AM. Effect of Different Time Periods of Vital Bleaching on Flexural Strength of Bovine Enamel and Dentin Complex. J Contemp Dent Pract 2007 March;(8)3:021-028.

scholarly journals Comparative Evaluation of Flexural Strength of Nano-zirconia-integrated Pressable Feldspathic and Lithium Disilicate Ceramics

2018 ◽  
Vol 19 (3) ◽  
pp. 339-344
Author(s):  
Chengalvarayan Sasikala ◽  
N Gopi Chander
Keyword(s):  
Flexural Strength ◽  
Computer Aided Design ◽  
Comparative Evaluation ◽  
Testing Machine ◽  
Lithium Disilicate ◽  
Control Group ◽  
Significant Difference ◽  
Computer Aided ◽  
Feldspathic Porcelain ◽  
Zirconia Nanoparticles

ABSTRACT Aim The purpose of the study was to evaluate and compare the flexural strength of nano-reinforced zirconia feldspathic porcelain, lithium disilicate ceramics, and zirconia. Materials and methods Ten bar-shaped specimens of computer-aided design (CAD)/computer-aided manufacturing (CAM) zirconia, reinforced feldspathic porcelain, and reinforced lithium disilicate were fabricated in accordance to International Organization for Standardization (ISO 6872; n = 10). Feldspathic porcelain and lithium disilicate ceramic specimens were reinforced with 5, 10, 15, and 20% of zirconia nanoparticles through a customized technique. The specimens were subjected to three-point flexural strength test using universal testing machine (UTM) and examined for crack propagation using a scanning electron microscope (SEM). One­way analysis of variance (ANOVA) and Tukey test were used to analyze the data (p < 0.05). Results The flexural strength of feldsphatic porcelain increased with the increase in the concentration of zirconia particles. The mean flexural strength of 5, 10, 15, and 20% nano-zirconia-incorporated lithium disilicate was 93.8, 97.1, 100.6, and 100.8 MPa respectively, and was lower than the control group (221.7 MPa). A significant difference in the flexural strength was found with the incorporation of nano-zirconia particles. Conclusion The flexural strength of zirconia-integrated feldspathic porcelain increased and lithium disilicate ceramics decreased with the nano-zirconia reinforcement. Clinical significance The simplified approach of reinforcing feldspathic porcelain with zirconia nanoparticles can be adapted in clinical situations of higher masticatory forces. How to cite this article Sasikala C, Chander NG. Comparative Evaluation of Flexural Strength of Nano-zirconia-integrated Pressable Feldspathic and Lithium Disilicate Ceramics. J Contemp Dent Pract 2018;19(3):339-344.

scholarly journals Reinforcement effect of intra-orifice barrier materials in teeth treated with regenerative endodontic procedure: Research article

2021 ◽  
Vol 15 (2) ◽  
pp. 111-114
Author(s):  
Sevinç Aktemur Türker ◽  
Keziban Olcay ◽  
Sena Kaşıkçı ◽  
Fatma Zühal Yurdagül
Keyword(s):  
Fracture Resistance ◽  
Testing Machine ◽  
Glass Ionomer Cement ◽  
In Vitro Study ◽  
Cervical Region ◽  
Control Group ◽  
Barrier Materials ◽  
Immature Teeth ◽  
Significant Difference

Background. Regenerative endodontic treatment (RET) is a clinically advanced procedure for necrotic immature teeth. However, root canal walls of these teeth are brittle especially in the cervical region and need reinforcement. This in vitro study is conducted to evaluate the effect of intra-orifice barrier materials on the fracture resistance of immature teeth treated with regenerative procedure. Methods. Forty-eight maxillary central incisors were used. Twelve intact teeth were selected for the control group. Remained teeth were prepared using peeso drills to simulate immature teeth and assigned into three groups according to the intra-orifice barrier material placed over MTA (n=12); Composite resin (CR), ProRoot MTA and Resin-modified glass ionomer cement (RMGIC). Fracture strength test was applied using a universal testing machine. One-way ANOVA and Tukey post hoc tests were used at P=0.05. Results. A significant difference was obtained among groups (P<0.05). MTA showed the lowest fracture resistance (P<0.05). However, no significant difference was found among RMGIC, CR, and control groups (P>0.05). Conclusion. Intra-orifice restorative materials have reinforcement affect in immature teeth treated with regenerative endodontic procedure. RMGIC or CR can be regarded as a viable choice to reduce the occurrence of cervical root fracture of immature teeth treated with a regenerative therapy.

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