Microhardness of light- and dual-polymerizable luting resins polymerized through 7.5-mm-thick endocrowns

Gregor, Ladislav; Bouillaguet, Serge; Onisor, Ioana Maria; Ardu, Stefano; Krejci, Ivo; Rocca, Giovanni Tommaso

doi:10.1016/j.prosdent.2014.02.008

Cited by 57 publications

(47 citation statements)

References 27 publications

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“…Previous studies even showed that periodontal ligament simulation could change the fracture strength results and failure modes in a positive way in that the ligament could serve as a shock absorber [28,29]. In previous studies while some did not fill the canal [30], others did fill the canals with endodontic filling materials [3,6,16]. Although filling the canal may be considered clinically more relevant, in this study, in order to find out the material strength and their adhesion to the tooth solely, this factor was not considered.…”

Section: Discussionmentioning

confidence: 99%

Fracture strength, failure type and Weibull characteristics of lithium disilicate and multiphase resin composite endocrowns under axial and lateral forces

et al. 2016

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OBJECTIVE Multiphase resin composite materials have been advocated as an alternative to reinforced ceramics but limited information is available to date on their stability. This in vitro study evaluated the effect of axial and lateral forces on the strength of endocrowns made of Li2Si2O5 and multiphase resin composite. METHODS Sound human molars (N=60, n=10 per group) were randomly divided into 6 groups: Group C: Control, no preparation or restoration; Group LI: Endocrown made of Li2Si2O5 (IPS e.max CAD) and Group LA: Endocrown made of multiphase resin composite material (Lava Ultimate). After decapitation and endodontic preparation, immediate dentin sealing was performed. Following CAD/CAM fabrication, their cementation surfaces were silica coated (CoJet System) and silanized (ESPE-Sil). Endocrowns were then adhesively cemented (Variolink II). All specimens were thermocycled (×10,000 cycles). While half of the specimens in each group were subjected to axial (C(A), LI(A), LA(A)), the other half was subjected to lateral static (C(L), LI(L), LA(L)) loading (1mm/min). Failure type and location after debonding/fracture were classified. Data were analyzed using ANOVA and Tukey's post hoc test ( =0.05). Two-parameter Weibull distribution values including the Weibull modulus, scale (m) and shape (0), values were calculated. RESULTS Under axial loading, mean fracture strength (N) did not show significant difference between groups: LAA (2675±588)(a), LIA (2428±566)(a), CA (2151±672)(a) (p>0.05) and under lateral loading, LAL (838±169)(A) presented significantly lower mean values than those of other groups: CL (1499±418)(B), LIL (1118±173)(B) (p<0.05). Both endocrown materials and the control group were more vulnerable to lateral loading than axial loading. Under axial loading, Weibull distribution presented higher shape (0) for Groups LIA (5.35) and LAA (5.08) than that of the control (3.97) and under lateral loading LIL (7.5) showed higher shape (0) than those of other groups (4.69-6.46). After axial loading, failure types were mainly cohesive in the material and after lateral loading primarily adhesive between the material and dentin for both LI and LA, most of which were repairable. SIGNIFICANCE Under axial loading, molars restored with endocrowns performed similar with both Li2Si2O5 and multiphase resin composite but the latter was less durable under lateral loading. loading LI L (7.5) showed higher shape ( 0 ) than those of other groups (4.69-6.46). After axial loading, failure types were mainly cohesive in the material and after lateral loading primarily adhesive between the material and dentin for both LI and LA, most of which were repairable.Significance. Under axial loading, molars restored with endocrowns performed similar with both Li 2 Si 2 O 5 and multiphase resin composite but the latter was less durable under lateral loading.Keywords: CAD/CAM; Composite; Ceramic; Endocrowns; Endodontics; Hybrid materials; Lithium disilicate IntroductionSevere coronal tooth structure loss due to extensive caries o...

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Section: Discussionmentioning

confidence: 99%

Fracture strength, failure type and Weibull characteristics of lithium disilicate and multiphase resin composite endocrowns under axial and lateral forces

et al. 2016

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“…However, the process of polymerization of resin cements was previously characterized using Knoop-hardness [30, 31]. Vickers [32, 33] and Knoop hardness [34] have been applied to test the degree of polymerization [32, 34] and polymerization shrinkage [33]. All 4 tested cements reached a constant level of hardness after 1 day of storage time, indicating that the polymerization was substantially finished.…”

Section: Discussionmentioning

confidence: 99%

Assessing degradation of composite resin cements during artificial aging by Martens hardness

2017

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BackgroundAim of the study was to verify the efficiency of Martens hardness measurements in detecting the degradation of composite resin cements during artificial aging.MethodsFour cements were used: Variolink II (VL2), RelyX Unicem 2 Automix (RUN), PermaFlo DC (PDC), and DuoCem (DCM). Specimens for Martens hardness measurements were light-cured and stored in water at 37 °C for 1 day to allow complete polymerization (baseline). Subsequently the specimens were artificially aged by water storage at 37 °C or thermal cycling (n = 6). Hardness was measured at baseline as well as after 1, 4, 9 and 16 days of aging. Specimens for indirect tensile strength measurements were produced in a similar manner. Indirect tensile strength was measured at baseline and after 16 days of aging (n = 10). The results were statistically analyzed using one-way ANOVA (α = 0.05).ResultsAfter water storage for 16 days hardness was significantly reduced for VL2, RUN and DCM while hardness of PDC as well as indirect tensile strength of all cements were not significantly affected. Thermal cycling significantly reduced both, hardness and indirect tensile strength for all cements. No general correlation was found between Martens hardness and indirect tensile strength. However, when each material was analyzed separately, relative change of hardness and of indirect tensile strength revealed a strong linear correlation.ConclusionsMartens hardness is a sensible test method to assess aging of resin composite cements during thermal cycling that is easy to perform.

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“…A better light penetration through the definitive restoration during light polymerization can therefore be achieved, allowing the use of light-cured luting resin composites for cementation in alternative to the chemical or dual cured resins. 16 If the pulp chamber cavity is completely filled by a resin base, the coronal restoration is better referred to as an overlay restoration rather than an endocrown.…”

Section: Introductionmentioning

confidence: 99%

The effect of a fiber reinforced cavity configuration on load bearing capacity and failure mode of endodontically treated molars restored with CAD/CAM resin composite overlay restorations

Rocca

Saratti

Cattani-Lorente

et al. 2015

Journal of Dentistry

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Microhardness of light- and dual-polymerizable luting resins polymerized through 7.5-mm-thick endocrowns

Cited by 57 publications

References 27 publications

Fracture strength, failure type and Weibull characteristics of lithium disilicate and multiphase resin composite endocrowns under axial and lateral forces

Fracture strength, failure type and Weibull characteristics of lithium disilicate and multiphase resin composite endocrowns under axial and lateral forces

Assessing degradation of composite resin cements during artificial aging by Martens hardness

The effect of a fiber reinforced cavity configuration on load bearing capacity and failure mode of endodontically treated molars restored with CAD/CAM resin composite overlay restorations

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