Influence of Ceramic Thickness and Ceramic Materials on Fracture Resistance of Posterior Partial Coverage Restorations

2015 ◽  
Vol 40 (2) ◽  
pp. 211-217 ◽  
Author(s):  
EM Bakeman ◽  
N Rego ◽  
Y Chaiyabutr ◽  
JC Kois
Keyword(s):  
Glass Ceramic ◽  
Fracture Resistance ◽  
Testing Machine ◽  
Lithium Disilicate ◽  
Ceramic Materials ◽  
Tooth Structure ◽  
Partial Coverage ◽  
Significant Difference ◽  
Ceramic Thickness ◽  
Ceramic Restorations

SUMMARY This study evaluated the influence of ceramic thickness and ceramic materials on fracture resistance of posterior partial coverage ceramic restorations. Forty extracted molars were allocated into four groups (n=10) to test for two variables: 1) the thickness of ceramic (1 mm or 2 mm) and 2) the ceramic materials (a lithium disilicate glass-ceramic [IPS e.max] or leucite-reinforced glass ceramic [IPS Empress]). All ceramic restorations were luted with resin cement (Variolink II) on the prepared teeth. These luted specimens were loaded to failure in a universal testing machine, in the compression mode, with a crosshead speed of 1.0 mm/min. The data were analyzed using two-way analysis of variance and the Tukey Honestly Significantly Different multiple comparison test (α =0.05). The fracture resistance revealed a significant effect for materials (p<0.001); however, the thickness of ceramic was not significant (p=0.074), and the interaction between the thickness of ceramic and the materials was not significant (p=0.406). Mean (standard deviation) fracture resistance values were as follows: a 2-mm thickness of a lithium disilicate bonded to tooth structure (2505 [401] N) revealed a significantly higher fracture resistance than did a 1-mm thickness of leucite-reinforced (1569 [452] N) and a 2-mm thickness of leucite-reinforced ceramic bonded to tooth structure (1716 [436] N) (p<0.05). There was no significant difference in fracture resistance values between a lithium disilicate ceramic at 1-mm thickness (2105 [567] N) and at 2-mm thickness. Using a lithium disilicate glass ceramic for partial coverage restoration significantly improved fracture resistance compared to using a leucite-reinforced glass ceramic. The thickness of ceramic had no significant effect on fracture resistance when the ceramics were bonded to the underlying tooth structure.

scholarly journals Overlays or Ceramic Fragments for Tooth Restoration: An Analysis of Fracture Resistance

2014 ◽  
Vol 15 (1) ◽  
pp. 56-60
Author(s):  
Matheus Coelho Bandéca ◽  
Adriana Santos Malheiros ◽  
Rudys Rodolfo de Jesus Tavarez ◽  
Leily Macedo Firoozmand ◽  
Mônica Barros Silva
Keyword(s):  
Fracture Resistance ◽  
Testing Machine ◽  
Resin Cement ◽  
Posterior Teeth ◽  
Tooth Structure ◽  
Significant Difference ◽  
Group 3 ◽  
Group 2 ◽  
Ceramic Restorations ◽  
Group 1

ABSTRACT Purpose The aim of this study was to evaluate the mode of fracture and resistance of partial ceramic restorations of posterior teeth. Materials and methods Thirty healthy upper premolars were selected and divided into three groups (n = 10): Group 1— control, healthy unrestored teeth, group 2—teeth restored with ceramic fragments; and group 3—teeth restored with ceramic overlays. The restorations were manufactured with feldspathic ceramic and cemented with RelyX ARC resin cement. After being stored in distilled water for 7 days, the teeth were subjected to axial compression mechanical testing with a universal testing machine. Force was applied to the long axis of the tooth at a speed of 0.5 mm/min until fracture. The data were analyzed with one-way ANOVA and Tukey's test (5%). The mode of fracture was scored according to the degree of involvement of the tooth structure and the type of restoration. Results A significant difference (p < 0.05) was showed between groups 2 (1155 N) and 3 (846.6 N), but there was no significant difference between group 1 and the other groups (1046 N), More extensive fractures were prevalent in the healthy teeth group (Group 1), which had no occlusal coverage; less severe fractures were found in groups 2 and 3. Conclusion We conclude that teeth restored with ceramic fragments may offer greater resistance to fractures compared to teeth that have overlay restorations. How to cite this article de Jesus Tavarez RR, Firoozmand LM, Silva MB, Malheiros AS, Bandéca MC. Overlays or Ceramic Fragments for Tooth Restoration: An Analysis of Fracture Resistance. J Contemp Dent Pract 2014;15(1):56-60.

scholarly journals LED and Halogen Light Transmission through a CAD/CAM Lithium Disilicate Glass-Ceramic

2015 ◽  
Vol 26 (6) ◽  
pp. 648-653 ◽  
Author(s):  
Carolina Nemesio de Barros Pereira ◽  
Cláudia Silami de Magalhães ◽  
Bruno Daleprane ◽  
Rogéli Tibúrcio Ribeiro da Cunha Peixoto ◽  
Raquel da Conceição Ferreira ◽  
...  
Keyword(s):  
Regression Model ◽  
Glass Ceramic ◽  
Light Transmission ◽  
Light Attenuation ◽  
Lithium Disilicate ◽  
Strong Negative Correlation ◽  
Halogen Light ◽  
Significant Difference ◽  
Cad Cam ◽  
Ceramic Thickness

The effect of thickness, shade and translucency of CAD/CAM lithium disilicate glass-ceramic on light transmission of light-emitting diode (LED) and quartz-tungsten-halogen units (QTH) were evaluated. Ceramic IPS e.max CAD shades A1, A2, A3, A3.5, high (HT) and low (LT) translucency were cut (1, 2, 3, 4 and 5 mm). Light sources emission spectra were determined. Light intensity incident and transmitted through each ceramic sample was measured to determine light transmission percentage (TP). Statistical analysis used a linear regression model. There was significant interaction between light source and ceramic translucency (p=0.008) and strong negative correlation (R=-0.845, p<0.001) between ceramic thickness and TP. Increasing one unit in thickness led to 3.17 reduction in TP. There was no significant difference in TP (p=0.124) between shades A1 (ß1=0) and A2 (ß1=-0.45) but significant reduction occurred for A3 (ß1=-0.83) and A3.5 (ß1=-2.18). The interaction QTH/HT provided higher TP (ß1=0) than LED/HT (ß1=-2.92), QTH/LT (ß1=-3.75) and LED/LT (ß1=-5.58). Light transmission was more effective using halogen source and high-translucency ceramics, decreased as the ceramic thickness increased and was higher for the lighter shades, A1 and A2. From the regression model (R2=0.85), an equation was obtained to estimate TP value using each variable ß1 found. A maximum TP of 25% for QTH and 20% for LED was found, suggesting that ceramic light attenuation could compromise light cured and dual cure resin cements polymerization.

scholarly journals Effect of Thermo-Mechanical Aging and Repressing on Fracture Resistance of Lithium Disilicate Crowns

2021 ◽  
Vol 24 (3) ◽  
Author(s):  
Amr El-Etreby ◽  
Mahmoud Metwally ◽  
Gihan EL-Nagar
Keyword(s):  
Glass Ceramic ◽  
Fracture Resistance ◽  
Glass Ceramics ◽  
Lithium Disilicate ◽  
Mean Value ◽  
Resistance Testing ◽  
Novel Approach ◽  
Significant Difference ◽  
Keywords Fracture ◽  
Mechanical Aging

Objective: The recycling of heat pressed lithium disilicate glass-ceramic leftover material has been reported to be done by dental laboratories. The effect of this procedure on the fracture resistance of single crowns is unknown, especially when it is functioning inside the oral cavity with subsequent exposure to temperature changes and cycles of mastication. Material and Methods: A total of 28 lithium disilicate glass-ceramic crowns (IPS emax Press) were constructed and randomly assigned into two groups (n = 14); Group (P): Included crowns fabricated from new e.max ingots. Group (R): Included crowns fabricated from repressed e.max buttons. Specimens of each group were divided into two equal subgroups (n = 7) according to whether the aging of specimens will be performed or not before fracture resistance testing. Subgroup (N), samples were subjected to fracture resistance without thermo-mechanical aging, while subgroup (A), samples were subjected to thermo-cycling and cyclic loading before being subjected to fracture strength testing. Different methods; SEM, XRD, EDAX were used to characterize the properties of lithium disilicate glass-ceramics before and after repressing. Results: The highest statistically significant fracture resistance value was recorded for the subgroup (RN) repressed/non-aged, followed by the subgroup repressed/aged (RA), while the lowest statistically significant mean value was recorded for the subgroup pressed/aged (PA). There was no significant difference between pressed/non-aged (PN) and repressed/aged (RA) subgroups. Conclusion: Repressing of leftover buttons may increase the fracture resistance of IPS emax Press crowns. Thermo-mechanical aging may negatively affect the fracture resistance of IPS emax Press crowns, yet Repressing may decrease this effect. Clinical implications: This is a novel approach that targets a point of research that has not been investigated before. It elaborates how repressing may decrease the effect of aging and increase the fracture resistance of lithium disilicate crowns. Thus, recycling of lithium disilicate glass ceramics might decrease its failure and prolong their serviceability.   Keywords Fracture resistance; Heat pressed; Lithium disilicate; Recycling; Repressing; Thermo-mechanical aging.

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

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.

scholarly journals In Vitro Comparative Analysis of Fracture Resistance of Lithium Disilicate Endocrown and Prefabricated Zirconium Crown in Pulpotomized Primary Molars

2019 ◽  
Vol 7 (23) ◽  
pp. 4094-4100
Author(s):  
Yasmine El Makawi ◽  
Nagwa Khattab
Keyword(s):  
Fracture Resistance ◽  
Testing Machine ◽  
Compressive Force ◽  
Lithium Disilicate ◽  
Resin Cement ◽  
Primary Molars ◽  
Second Primary ◽  
Post Hoc ◽  
Ceramic Restorations

AIM: This study aimed to evaluate the effect of lithium disilicate endocrowns compared to prefabricated zirconia crown used for restoring pulpotomized primary molars, on their Fracture Resistance and to compare the loads to failure these different ceramic restorations with previously reported posterior occlusal forces. METHODS: Twenty mandibular left second primary molars were randomly distributed into two groups (n = 10 in each group) the zirconia Crown (Nusmile zr.) Group (G1) and the lithium disilicate (IPS e.max Press) Endocrown Group (G2). In all groups pulpotomy procedure was done before preparation then each sample was prepared based on their allocated restoration, both zirconia crown (Nusmile zr.) and endocrown (IPS e.max Press) were cemented by dual-cure resin cement. All samples were loaded to failure using a universal testing machine (Instron, USA), and the compressive force was applied. The data were analysed using one-way (ANOVA) and Tukey’s post hoc significance difference tests. Differences were considered significant at (p< 0.05). RESULTS: Group zirconia crown (G1) showed significantly higher fracture strength than Group (G2) lithium disilicate endocrown (p < 0.05). CONCLUSION: The zirconia crown showed higher fracture resistance than lithium disilicate endocrown. However, both tested zirconia crown and lithium disilicate endocrown withstood the application of axial occlusal forces greater than the reference values for posterior occlusal loads.

scholarly journals Does Preheating Resin Cements Affect Fracture Resistance of Lithium Disilicate and Zirconia Restorations?

Materials ◽  
2021 ◽  
Vol 14 (19) ◽  
pp. 5603
Author(s):  
Amal Abdelsamad Sakrana ◽  
Walid Al-Zordk ◽  
Heba El-Sebaey ◽  
Ahmed Elsherbini ◽  
Mutlu Özcan
Keyword(s):  
Fracture Resistance ◽  
Lithium Disilicate ◽  
Resin Cement ◽  
Cement Type ◽  
Mean Values ◽  
Preheating Temperature ◽  
Significant Difference ◽  
Ceramic Restorations ◽  
The Impact ◽  
Adhesive Cement

This paper assesses the impact of preheating of adhesive cement on the fracture resistance of lithium disilicate and zirconia restorations. Methods: A total of 80 human maxillary premolar teeth were assigned into 8 groups (n = 10) according to material type (either lithium disilicate or zirconia) and type of resin cement (either LinkForce or Panavia SA) with preheating temperature at 54 °C or at room temperature (25 °C). Teeth were prepared and restored with either lithium disilicate or zirconia restorations. After cementation, specimens were thermal cycled (10,000 cycles, 5 °C̸55 °C), then load cycled for 240,000 cycles (50 N). Each specimen was statically loaded until fracture and the load (N) at fracture was recorded, then the failure mode was detected. Statistical analysis of data was performed (p ≤ 0.05). Results: There was no significant difference (p = 0.978) in fracture mean values between LinkForce and Panavia SA. Statistically significant difference (p = 0.001) was revealed between fracture resistance of lithium disilicate restorations cemented with LinkForce at 25 °C and at 54 °C; however there was no significant difference (p = 0.92) between the fracture resistance of lithium disilicate restorations cemented with Panavia SA used at 25 °C and at 54 °C. Regarding the interaction between ceramic material, cement type, and cement preheating, there was no significant effect (p > 0.05) in fracture resistance. The cement type does not influence the fracture resistance of ceramic restorations. Preheating of resin cement has negatively influenced the fracture resistance of all tested groups, except for lithium disilicate cemented using LinkForce cement.

scholarly journals Evaluation of fracture resistance of endodontically treated teeth restored with prefabricated posts and composites with varying quantities of remaining coronal tooth structure

2005 ◽  
Vol 13 (2) ◽  
pp. 141-146 ◽  
Author(s):  
Murilo Pereira de Melo ◽  
Accácio Lins do Valle ◽  
Jefferson Ricardo Pereira ◽  
Wellington Cardoso Bonachela ◽  
Luiz Fernando Pegoraro ◽  
...  
Keyword(s):  
Fracture Resistance ◽  
Testing Machine ◽  
Acrylic Resin ◽  
Group Iv ◽  
Coronal Structure ◽  
Endodontically Treated Teeth ◽  
Tooth Structure ◽  
Group Iii ◽  
Group I ◽  
Significant Difference

OBJECTIVES: The aim of this study was to evaluate the influence of remaining coronal tooth structure on endodontically treated teeth restored with prefabricated posts and two different composites for core build-up: dual-cured resin (Enforce Core) and light-cured resin (Z-250). METHODS: Fourty freshly extracted canines were endodontically treated and divided into four groups: Group I - teeth with 3mm remaining coronal structure, restored with Enforce Core; Group II - teeth with 3mm remaining coronal structure, restored with Z-250; Group III - teeth with no remaining coronal structure, restored with Enforce; Group IV - teeth with no remaining coronal structure, restored with Z-250. After restoration, the teeth were embedded in acrylic resin and the fracture resistance was measured on a universal testing machine at 45 degrees to the long axis of the tooth until failure. RESULTS: Data were analyzed by two-way analysis of variance, which showed significant differences between groups (p=0.00). The Tukey test did not show significant differences between specimens with and without remaining coronal structure. Conversely, significant difference was observed between groups with different core build-up. The highest values of fracture resistance were found in the group restored with light-cured resin. SIGNIFICANCE: The remaining coronal tooth structure did not influence the resistance of endodontically treated teeth; however, the change of core build-up was able to modify this resistence.

scholarly journals Impact of Chemical Aging on the Fracture Resistance of Two Ceramic Materials: Zirconia-Reinforced Lithium Silicate and Lithium Disilicate Ceramics

2020 ◽  
Vol 8 (D) ◽  
pp. 189-193
Author(s):  
Mohamed S. Mohamed ◽  
Cherif A. Mohsen ◽  
Hisham Katamish
Keyword(s):  
Fracture Resistance ◽  
Testing Machine ◽  
In Vitro Study ◽  
High Strength ◽  
Lithium Disilicate ◽  
Ceramic Materials ◽  
Lithium Silicate ◽  
Chemical Aging ◽  
Ceramic Blocks

BACKGROUND: The reason for the development of high strength zirconia is that zirconia offers enough high strength of about 1000 MPa and high strength glass ceramic in the range of 360–400 MPa, to provide safely ceramic options for many indications. AIM: This study aims to evaluate the fracture resistance of zirconia-reinforced lithium silicate (ZLS) ceramic and lithium disilicate ceramic restorations. MATERIALS AND METHODS: In this in vitro study, forty crowns were fabricated by CAD/CAM technology, all samples were divided into two groups (n = 20) according to ceramic material used: Group Z ZLS ceramic (celtra due) and Group L lithium disilicate ceramic blocks (IPS E-MAX). Further subdivided into two subgroups according to the aging procedure (n = 10): (a) Subgroup – ZA: Aging. (b) Subgroup – ZB: No aging. (c) Subgroup – LA: Aging. (d) Subgroup – LB: No aging. All samples were subjected to universal testing machine (Instron) to evaluate the effect of the chemical aging on the fracture resistance. STATISTICAL ANALYSIS: One-way ANOVA analysis was used to compare measurements among groups. RESULTS: ZLS showed higher fracture resistance than lithium disilicate, but there was no statistical difference between them. Aging affected on the fracture resistance of two different ceramic materials but within an acceptable range. CONCLUSION: ZLS gave rise to higher fracture resistance than lithium disilicate and aging decrease fracture resistance of both types of ceramic. The postulated hypothecs of this study were zirconia reinforced, lithium silicate will be higher fracture resistance than lithium disilicate, and chemical aging will have a huge effect.

scholarly journals Debonding Time and Dental Pulp Temperature With the Er, Cr: YSGG Laser for Debonding Feldespathic and Lithium Disilicate Veneers

2019 ◽  
Vol 10 (3) ◽  
pp. 211-214 ◽  
Author(s):  
Marzieh Alikhasi ◽  
Abbas Monzavi ◽  
Hooman Ebrahimi ◽  
Maryam Pirmoradian ◽  
Ahmadreza Shamshiri ◽  
...  
Keyword(s):  
Glass Ceramic ◽  
Temperature Increase ◽  
Lithium Disilicate ◽  
Ceramic Materials ◽  
Resin Cement ◽  
P Value ◽  
Significance Level ◽  
Ysgg Laser ◽  
Significant Difference ◽  
Pulp Temperature

Introduction: The removal of ceramic veneers is a time-consuming procedure in a dental office. Little research has been done in alternative removal techniques for ceramic veneers. The objective of this study was to evaluate the removal of feldspathic and lithium disilicate reinforced glass ceramic veneers by Er, Cr: YSGG and to measure debonding time and pulpal temperature increase during veneer removal. Methods: Fifty-seven bovine incisor teeth were prepared and divided into 3 groups. Ceramic specimens with a thickness of 0.7mm, a width of 4mm and a length of 8 mm were fabricated from feldspathic ceramic, lithium disilicate reinforced glass ceramic HT (high translucency) and lithium disilicate reinforced glass ceramic MO (medium opacity) (19 for each group). Specimens were cemented on the labial surface of incisors using resin cement. The Er, Cr: YSGG laser was applied to each specimen at 2.5 W and 25 Hz. Debonding time was measured for each specimen, and the intrapulpal temperature was detected in 3 specimens for each group. Data were analyzed via one-way analysis of variance (ANOVA) at significance level of 0.05 (α = 0.05). Results: Mean debonding time was 103.68 (26.76), 106.58 (47.22) and 103.84 (32.90) seconds for feldspathic, lithium disilicate MO, and lithium disilicate HT respectively. There was no significant statistical difference among the groups (P value = 0.96). The intrapulpal temperature increase was less than 1°C in all groups. Conclusion: Er, Cr: YSGG can successfully be used to efficiently debond feldspathic and lithium disilicate reinforced glass ceramic veneers. There was no significant difference for debonding time among these ceramic materials. During ceramic laminate veneer removal by laser irradiation, no irritating temperature rise was detected.

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.

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