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...

OBJECTIVES In this randomized split-mouth clinical trial the survival rate and quality of survival of indirect resin composite and ceramic laminate veneers were evaluated. METHODS A total of 48 indirect resin composite (Estenia; n = 24) and ceramic laminate veneers (IPS Empress Esthetic; n = 24) were placed on maxillary anterior teeth. Veneer preparations with incisal overlap were performed using a mock up technique. Survival of the restoration was considered the primary outcome measure and reported using Kaplan-Meier statistics and survival curves compared by means of Log Rank (Mantel-Cox) test. After luting, restorations were evaluated by calibrated operators at baseline and every year thereafter, using modified USPHS criteria and compared by means of Mann-Whitney U test. RESULTS In total, 6 failures were observed, consisting of debonding (n = 3) and fracture (n = 3), all in the group of the indirect resin composite laminate veneers. Cumulative chance on survival after 10 years of the indirect resin composite and ceramic veneers was 75% (se 3,8%) and 100% respectively (p = 0.013). Of the surviving 42 laminate veneers, the variables 'color match' (p = 0.002), 'surface roughness' (p = 0.000), 'fracture of the restoration' (p = 0.028), and 'wear of the restoration' (p = 0.014), were significantly less favourable among the composite laminate veneers as well. CONCLUSIONS The ceramic veneers on maxillary anterior teeth in this study performed significantly better compared to the composite indirect laminate veneers after a decade, both in terms of survival rate and in terms of quality of the surviving restorations. CLINICAL RELEVANCE When indicated, anterior ceramic laminate veneers may be preferred over indirect composite laminate veneers.

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Adhesive procedures have changed the way to restore endodontically treated teeth (ETT). It started with the shift from cast post-and-core to fiber post. The original focus on strength also shifted towards failure modes, revealing that catastrophic failures are still a concern when restoring endodontically-treated teeth even with fiber posts. As an alternative, postless approaches have been proposed in order to improve the chances of repair. The goal of this critical review is to present a survey of the current knowledge on adhesive approaches to restore endodontically treated teeth with and without extensive coronal tissue loss. The preservation of tooth structure of endodontically treated teeth is paramount. Partial versus full coverage of ETT, the role of the ferrule, the post type effect on catastrophic failures and postless alternatives as endocrowns and postless build-ups are reviewed. There is a consensus that the remaining tooth structure plays an important role in ETT survival, although the current literature still is contradictory on the influence of post type on root fractures as well as the benefits of avoiding a post or partially restoring a tooth. More clinical studies should be carried out with the modern postless adhesive alternatives to conventional approaches.

OBJECTIVES Adhesion on dentin is less reliable than on enamel, which could affect the durability of laminate veneers (LV). Immediate dentin sealing (IDS) is suggested instead of delayed dentin sealing (DDS) to overcome hypersensitivity and prevent debonding from dentin. This study evaluated the effect of IDS and DDS on the durability of Li2Si2O5 laminate veneers in vitro. METHODS Window preparations were made on the labial surfaces of sound maxillary central incisors (N=50). They were randomly divided into five groups: Group 1: Enamel only+H3PO4+Adhesive (control); Group 2: <1/4 dentin+H3PO4+DDS (2 weeks later); Group 3: Complete dentin+H3PO4+DDS (2 weeks later); Group 4: <1/4 dentin+H3PO4+IDS; Group 5: Complete dentin+H3PO4+IDS. Li2Si2O5 laminate veneers (e.max Press) were bonded to the labial surfaces of the teeth with adhesive resin cement (Variolink Veneer). IDS layers were silicacoated (CoJet System) and silanized (ESPE-Sil). The teeth with their bonded laminates were thermocycled (10.000× cycles) and then subjected to static loading (1mm/min). Failure type and location after debonding 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 Mean fracture strength (N) per group in descending order was as follows: Group 5 (576±254), Group 4 (478±216), Group 1 (473±159), Group 2 (465±186), and Group 3 (314±137). The presence of complete dentin exposure sealed with DDS after 2 weeks on the bonded surface (Group 3) resulted in significantly lower fracture strength results than those in group 5 with IDS (p=0.034). Weibull distribution presented higher shape (0) for Group 1 (3.67), than those of other groups (2.51-2.89). Failure types were predominantly adhesive failure between the cement and the laminate veneer in Groups 1, 2, 4 whereas Group 3 presented more often complete adhesive failures between the cement and dentin. In Group 5, failures showed some IDS and cement with or without ceramic fracture attached on the tooth. SIGNIFICANCE When laminate veneers are bonded to a large dentin substrate, application of immediate dentin sealing improves adhesion and thereby, the fracture strength of Li2Si2O5 laminate veneers. Gresnigt, Marco M M; Cune, Marco S; de Roos, Joanne G; Özcan, Mutlu (2016) ABSTRACTObjectives. Adhesion on dentin is less reliable than on enamel, which could affect

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