Fracture RESISTANCE and Color Stability of two hybrid ceramic veneers VERSUS LITHIUM DISILICATE GLASS CERAMIC VENEERS

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.

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FRACTURE RESISTANCE, FINITE ELEMENT ANALYSIS AND WEIBULL RISK OF FAILURE FOR ENDODONTICALLY TREATED MOLARS RESTORED WITH LITHIUM DISILICATE AND HYBRID CERAMIC ENDOCROWNS WITH TWO PREPARATION DESIGNS

Egyptian Dental Journal ◽

10.21608/edj.2017.76330 ◽

2017 ◽

Vol 63 (4) ◽

pp. 2803-2820

Author(s):

Rania Amin ◽

Mostafa Abdellatif ◽

Heba Eltayeb

Keyword(s):

Finite Element Analysis ◽

Finite Element ◽

Fracture Resistance ◽

Lithium Disilicate ◽

Element Analysis ◽

Risk Of Failure ◽

Hybrid Ceramic

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

Operative Dentistry ◽

10.2341/12-459-l ◽

2015 ◽

Vol 40 (2) ◽

pp. 211-217 ◽

Cited By ~ 14

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.

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Effect of adhesive luting on the fracture resistance of zirconia compared to that of composite resin and lithium disilicate glass ceramic

Restorative Dentistry & Endodontics ◽

10.5395/rde.2017.42.1.1 ◽

2017 ◽

Vol 42 (1) ◽

pp. 1 ◽

Cited By ~ 3

Author(s):

Myung-Jin Lim ◽

Kwang-Won Lee

Keyword(s):

Glass Ceramic ◽

Fracture Resistance ◽

Composite Resin ◽

Lithium Disilicate ◽

Adhesive Luting

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Fracture Resistance of Teeth Restored With All-ceramic Inlays and Onlays: An In Vitro Study

Operative Dentistry ◽

10.2341/12-211-l ◽

2013 ◽

Vol 38 (6) ◽

pp. 626-634 ◽

Cited By ~ 18

Author(s):

S Saridag ◽

M Sevimay ◽

G Pekkan

Keyword(s):

Fracture Strength ◽

Glass Ceramic ◽

Fracture Resistance ◽

In Vitro Study ◽

Lithium Disilicate ◽

Vitro Study ◽

Zirconia Ceramic ◽

All Ceramic ◽

Restorative Materials

SUMMARY Fracture resistance of inlays and onlays may be influenced by the quantity of the dental structure removed and the restorative materials used. The purpose of this in vitro study was to evaluate the effects of two different cavity preparation designs and all-ceramic restorative materials on the fracture resistance of the tooth-restoration complex. Fifty mandibular third molar teeth were randomly divided into the following five groups: group 1: intact teeth (control); group 2: inlay preparations, lithium-disilicate glass-ceramic (IPS e.max Press, Ivoclar Vivadent AG, Schaan, Liechtenstein); group 3: inlay preparations, zirconia ceramic (ICE Zirkon, Zirkonzahn SRL, Gais, Italy); group 4: onlay preparations, lithium-disilicate glass-ceramic (IPS e.max Press); and group 5: onlay preparations, zirconia ceramic (ICE Zirkon). The inlay and onlay restorations were adhesively cemented with dual polymerizing resin cement (Variolink II, Ivoclar Vivadent AG). After thermal cycling (5° to 55°C × 5000 cycles), specimens were subjected to a compressive load until fracture at a crosshead speed of 0.5 mm/min. Statistical analyses were performed using one-way analysis of variance and Tukey HSD tests. The fracture strength values were significantly higher in the inlay group (2646.7 ± 360.4) restored with lithium-disilicate glass-ceramic than those of the onlay group (1673.6 ± 677) restored with lithium-disilicate glass-ceramic. The fracture strength values of teeth restored with inlays using zirconia ceramic (2849 ± 328) and onlays with zirconia ceramic (2796.3 ± 337.3) were similar to those of the intact teeth (2905.3 ± 398.8). In the IPS e.max Press groups, as the preparation amount was increased (from inlay to onlay preparation), the fracture resistance was decreased. In the ICE Zirkon ceramic groups, the preparation type did not affect the fracture resistance results.

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