Fracture Resistance of Various Temporary Crown Materials

2007 ◽  
Vol 8 (1) ◽  
pp. 44-51 ◽  
Author(s):  
Asude Yilmaz ◽  
Seyfettin Baydaş

Abstract Aim The aim of this study was to evaluate the fracture resistance of various provisional crown materials using an in vitro model test system. Methods and Materials In the present study polycarbonate crowns, prefabricated by the manufacturer (3M Polycarbonate Crown), and the temporary crowns, fabricated in the dental laboratory environment, were fabricated using bis-acryl composite (Protemp II), autopolymerizing PMMA resin (BISICO Temp S), and heatpolymerized PMMA resin (Major C&B-V Dentine). All temporary crowns were stored in distilled water for 24 hours at room temperature prior to testing. The crowns were seated on metal dies, fabricated from Cr-Co alloy (AZ Dental, Konstanz, Germany), and then tested using the indenter of a Hounsfield testing machine (Hounsfield Tensometer, Hounsfield Test Equipment, Raydon, England). The tip of the indenter was located at a position one-third of the way down the inciso-palatine surface at 135°. The data were statistically analyzed for differences using one-way analysis of variance (ANOVA) and the Tukey HSD test (P<.05). Additionally, the types of failure obtained from the fracture load test were examined using 10X magnification with a stereo microscope. Results The results of the present study indicated polycarbonate crowns were significantly different from the BISICO Temp S, Protemp II, and Major C&B-V Dentine (P<.05) groups. Conclusion This in vitro study shows polycarbonate crowns may be preferable to the other types of temporary crowns used in this study. Citation Yilmaz A, Baydaş S. Fracture Resistance of Various Temporary Crown Materials. J Contemp Dent Pract 2007 January;(8)1:044-051.

PLoS ONE ◽  
2021 ◽  
Vol 16 (4) ◽  
pp. e0249208
Author(s):  
Seung-rye Song ◽  
Kyeong-Mee Park ◽  
Bock-Young Jung

This study aimed to analyze fracture strength in vitro by varying the axial height of the titanium insert and the labial height of the zirconia abutment in an internal connection implant to identify the titanium insert axial height with optimal mechanical stability. Sixty implants with an internal connection system were used. Two-piece zirconia abutments were used with the titanium inserts. Combinations of different titanium insert axial heights (mm) and zirconia abutment labial heights (mm) constituted five groups: Gr1 (1–3), Gr2 (3–3), Gr3 (3–5), Gr4 (5–3), and Gr5 (5–5). After thermocycling, a fracture load test was performed with a universal testing machine. The initial deformation load and the fracture load were measured and analyzed. The fractured surface and cross-section of the specimens were examined by scanning electron microscopy (SEM). The groups of titanium inserts with axial heights of 3 mm and 5 mm showed significantly greater initial deformation load and fracture load than the group with an axial height of 1 mm (p < 0.05), but there was no significant difference between the two groups with axial heights of 3 mm and 5 mm. The labial height of the zirconia abutment had no significant influence on the initial deformation load and fracture load. In some specimens in Gr4 and Gr5, cracking or bending of the titanium insert and abutment screw was observed on SEM. The axial height of the titanium insert should be designed to not be less than 3 mm to increase the fracture strength and promote the long-term stability of implants.


F1000Research ◽  
2019 ◽  
Vol 8 ◽  
pp. 1491 ◽  
Author(s):  
Bushra Mohammed ◽  
Jylan EL-Guindy

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.


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.


2015 ◽  
Vol 03 (02) ◽  
pp. 080-084
Author(s):  
Vijay Singh ◽  
Poonam Bogra ◽  
Saurabh Gupta ◽  
Navneet Kukreja ◽  
Neha Gupta

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.


2017 ◽  
Vol 7 (2) ◽  
pp. 97-102
Author(s):  
Sabita M Ram ◽  
Naisargi Shah ◽  
Amit M Gaikwad

ABSTRACT Aim To comparatively evaluate the fracture resistance of endodontically treated teeth restored with light-cured composite resin core using two different designs of prefabricated metal posts. Materials and methods A total of 30 single-rooted anterior teeth were selected for the study and endodontically treated. Teeth were sectioned 2 mm above the cementoenamel junction and were randomly divided into two groups (n = 15). Teeth in group I were restored with Parallel post—EG post and group II with parallel post with coronal flare—i post. Light-cured composite core buildup was done in all samples using a customized core former. Compressive load was applied at a 135° angle to the long axis of the tooth at a cross-head speed of 1 mm/minute until visible signs of fracture were observed. Levene's test and t-test were used to determine the difference of the failure loads between the groups (α = 0.05). Results The mean values (standard deviation [SD]) for fracture resistance were 295.55 N and 469.59 N for parallel post—EG post and parallel post with coronal flare—i post respectively. Since the p-value for the t-test is less than 0.05, it indicates that we should reject null hypothesis and conclude that the mean fracture load of parallel post with coronal flare—i post is significantly more than that of mean fracture load of parallel post—EG post. Conclusion The study conducted evaluated that the fracture resistance of endodontically treated teeth with parallel post with coronal flare—i post and core buildup had better strength as compared with parallel post—EG post and core buildup. Clinical significance The present study will help the clinician to select the appropriate prefabricated metal post that will fit exactly into the coronal flare of the canal improving clinical performance, thus increasing the longevity of the restoration. How to cite this article Gaikwad AM, Shah N, Ram SM. A Comparative Evaluation of Fracture Resistance of Endodontically Treated Teeth restored with Composite Resin Core using Two Different Designs of Prefabricated Metal Posts: An in vitro Study. J Contemp Dent 2017;7(2):97-102.


2020 ◽  
Vol 14 (02) ◽  
pp. 245-249
Author(s):  
Haider Hasan Jasim ◽  
Meelad Basil Findakly ◽  
Nada Ali Mahdi ◽  
Mustafa Tariq Mutar

Abstract Objectives The aim of this study was to compare the effects of two margin designs (shoulderless and slight chamfer) with two occlusal thicknesses on fracture resistance and failure mode of the monolithic zirconia crowns. Materials and Methods Forty nickel–chromium dies were duplicated from the previous two prepared teeth using a three-dimensional optical scanner. Nickel–chromium supporting dies were divided into two main groups (n = 20) according to the type of margin design: group A, slight chamfer margin design and group B, shoulderless margin design. These groups were further divided into two subgroups according to the occlusal thicknesses (0.5 and 1 mm). The digital imaging of each die was done using a three-dimensional optical scanner, then zirconia blocks were milled by 5-axis machine. The crowns were cleaned by alcohol, air dried, and cemented by resin cement. Next, the crowns were subjected to 500 hot and cold cycles (30 seconds for each cycle). The samples were subjected to a static load until failure using an electronic universal testing machine and fracture resistance was recorded in Newton (N). Statistical Analysis Data were analyzed using the test of normality (Shapiro–Wilk test) and two-way analysis of variance (ANOVA) test. Results  The highest mean fracture load was recorded by the shoulderless (1 mm occlusal thickness) subgroup (3,992.5 N), followed by shoulderless (0.5 mm occlusal thickness) subgroup (3,244.4 N), and the slight chamfer (1 mm occlusal thickness) subgroup (2,811 N). The lowest mean of fracture load was recorded by slight chamfer (0.5 mm occlusal thickness) subgroup (1,632.9 N). The two-way ANOVA test revealed a significant difference between the four subgroups. Regarding the fracture mode, the slight chamfer subgroups showed a severe fracture of the restoration while the shoulderless subgroups showed a fracture through the midline of the restoration. Conclusion Within the limitation of the comparative study, shoulderless margin design has a more favorable outcome than a slight chamfer design in all thicknesses. Although the restoration with reduced occlusal thickness has lower fracture resistance than 1 mm occlusal thickness, the 0.5 mm restorations still can tolerate occlusal forces.


2014 ◽  
Vol 04 (03) ◽  
pp. 075-079
Author(s):  
Kiran Halkai ◽  
Rahul Halkai ◽  
Mithra N. Hegde ◽  
Vijay Kumar ◽  

Abstract Aim: To compare and evaluate in-vitro the fracture resistance of endodontically treated teeth obturated with resilon & epiphany sealer and guttapercha using different sealers. Epoxy resin based sealer AH-plus and zinc oxide eugenol based sealer-TubliSeal (EWT). Methodology: sixty four human single rooted maxillary anterior teeth, cleaned stored in 0.9% saline. All the teeth were decoronated to root length 14mm and bucco-lingual diameter of 5-7mm, After access openings teeth were instrumented using K3.06 up to final apical size 30/.06 and randomly allocated into 4 experimental groups (n=16 per group). Group 1(Control group): teeth were instrumented but not obturated, Group 2: Resilon cones and epiphany SE-sealer. Group 3: guttapercha cones and epoxy based sealer AH plus. Group 4: guttapercha and Tubli seal EWT. Coronal seal was done using IRM cement. Each of the specimens were tested for fracture resistance by instron universal testing machine. Results: Higher fracture resistance values were observed for group 2 (Resilon & Epiphany SE sealer) followed by group 3(Guttapercha & AH Plus sealer) and group 4(Guttapercha & TubliSeal EWT) when compared to group1 (control-instrumented but not obturated). Conclusion: filling the root canals with contemporary polymer based root canal obturating system- Resilon increased the in vitro fracture resistance of endodontically treated teeth.


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.


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.


2020 ◽  
Author(s):  
Xia Juan ◽  
Wang weidong ◽  
Li Zhengmao ◽  
Lin Bingpeng ◽  
Zhang Qian ◽  
...  

Abstract Background: This study aims to compare the percentage of dentin removed, instrumentation efficacy, root canal filling and load at fracture between contracted endodontic cavities, and traditional endodontic cavities on root canal therapy in premolars. Methods: Forty extracted intact human first premolars were imaged with micro-CT and randomly assigned to the contracted endodontic cavity (CEC) or traditional endodontic cavity (TEC) groups. CEC was prepared with the aid of a 3D-printed template, canals were prepared with a 0.04 taper M-Two rotary instrument, and cavities were restored with resin. Specimens were loaded to fracture in an Instron Universal Testing Machine after a fatigue phase. The data were analyzed by the independent samples T test and Mann-Whitney U test, appropriate post hoc tests. Results: In the premolars tested in vitro, the percentage of dentin removed in the premolars with two dental roots in the CEC group (3.85% ± 0.42%) was significantly smaller (P < 0.05) than in the TEC group (4.94% ± 0.5%). The untouched canal wall (UCW) after instrumentation for TECs (16.43% ± 6.56%) was significantly lower (P< .05) than the UCW (24.42% ± 9.19%) for CECs in single-rooted premolars. No significant differences were observed in the increased canal volume and surface areas in premolars between the TEC and CEC groups (P > 0.05). CECs conserved coronal dentin in premolars with two dental roots but no impact on the instrument efficacy. There were no differences between the CEC groups and the TEC groups in the percentage of filling material and voids (P > 0.05). In addition, the mean load at failure of premolars did not significantly differ between the CEC and TEC groups and there was no significant difference in the type of fracture (P > 0.05). Conclusion: The results of this study suggest that CEC could not improve the fracture resistance of the endodontically treated premolars. The instrumentation efficacy and the percentage of filling material did not significantly differ between CECs and TECs in premolars. Keywords: 3D-printed template, contracted endodontic cavities, instrumentation efficacy, root canal filling, fracture resistance


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