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Objective: To give a current review of silane adhesion chemistry, applications of silane coupling agents and related surface pretreatment methods in contemporary dentistry., Methods: Silane coupling agents are adhesion promoters to chemically unify dissimilar materials used in dentistry. Silanes are very effective in adhesion promotion between resin composites and silica-based or silica-coated indirect restorative materials. It is generally accepted that for non-silica-based restorations, surface pretreatment is a mandatory preliminary step to increase the silica content and then, with help of silane, improve resin bonding. This review discusses the silane-based adhesion chemistry, silane applications in dentistry, surface pretreatment methods, and presents the recent development of silane coupling agents., Results: A silane coupling agent is considered a reliable, good adhesion promoter to silica-based (or silica-coated) indirect restorations. Surface pre-treatment steps, e.g., acid etching for porcelain and tribo-chemical silica-coating for metal alloys, is used before silanization to attain strong, durable bonding of the substrate to resin composite. In clinical practice, however, the main problem of resin bonding using silanes and other coupling agents is the weakening of the bond (degradation) in the wet oral environment over time., Significance: A silane coupling agent is a justified and popular adhesion promoter (adhesive primer) used in dentistry. The commercial available silane coupling agents can fulfil the requirements in clinical practice for durable bonding. Development of new silane coupling agents, their optimization, and surface treatment methods are in progress to address the long term resin bond durability and are highly important., (Copyright © 2017 The Academy of Dental Materials. Published by Elsevier Ltd. All rights reserved.)

This study aimed to investigate the effects of femtosecond laser (Fs) and/or air-abrasion protocols on surface roughness (Ra) of zirconia and resin bond strength. Eighty zirconia samples were randomly divided into eight subgroups according to surface treatment protocols: Control (C), Air-abrasion before sintering (ABS), Air-abrasion after sintering (AAS), Air-abrasion before and after sintering (ABS + AAS), Fs laser before sintering (FBS), Fs laser before sintering + air-abrasion after sintering (FBS + AAS), Fs laser after sintering (FAS), and Fs laser after sintering + air-abrasion after sintering (FAS + AAS). Measurements of Ra values were obtained using a surface profilometer. Surface morphological properties were evaluated with scanning electron microscopy (SEM), and crystallographic changes were examined by X-Ray diffractometry (XRD). Self-adhesive resin cement was bonded to zirconia samples, and shear bond strength (SBS) tests were performed. The data were statistically analyzed by one-way ANOVA, followed by Tamhane tests. The control group displayed the lowest Ra and SBS values among all groups. The highest Ra and SBS values were found in the FBS and FBS + AAS groups. Air-abrasion applied before sintering significantly increased the Ra of specimens. FAS, FAS + AAS, and ABS + AAS groups exhibited higher SBS values than AAS and ABS (p < .05). Air-abrasion applied after Fs laser did not produce any significant change in the Ra and SBS compared to Fs laser alone (p > .05). Femtosecond laser application may be a promising method to enhance the surface roughness of zirconia and improve resin bond strength. Air-abrasion at pre- and post-sintered stages may also be a viable surface treatment option., (© 2020 Wiley Periodicals LLC.)

Background: Resin cements often require substrate-specific pretreatment. Recently, universal adhesive systems have been introduced, simplifying procedures by eliminating the need for multiple adhesives and offering options that do not require light curing. This study investigated the bonding performance of universal adhesive systems combined with dual-polymerising resin cements on enamel, dentin, zirconia, lithium disilicate ceramics (LDS), and resin blocks. Methods: Two universal adhesive and dual-polymerising resin cement combinations from the same manufacturer were tested: Bondmer Lightless II (BLII) with Estecem II (ECII), and Scotchbond Universal Plus adhesive (SBU) with RelyX Universal resin cement (RXU). Enamel, dentin, zirconia (Katana Zirconia UTML), LDS (IPS e.max CAD CEREC), and resin blocks (Katana Avencia P Block) were used as substrates. The universal adhesive was applied to all bonding surfaces, followed by resin cement application in micro-bore Tygon tubes and light curing for 40 s. Micro-shear bond strength (μSBS) was measured after 0 thermal cycles (0TC) or 10,000 thermal cycles (10kTC) (n = 20). Statistical analyses were conducted using t-tests and Welch's t-tests with Bonferroni correction (α = 0.05), and failure modes were examined. Results: In the BLII/ECII group, the mean μSBS values exceeded 15 MPa for all substrates at 0TC. After thermocycling, μSBS increased significantly for the enamel (p < 0.05), remained unchanged for dentin and zirconia (p > 0.05) and decreased for LDS and resin blocks (p < 0.05). In the SBU/RXU group, 0TC μSBS values exceeded 15 MPa for enamel, zirconia, and resin blocks, but thermocycling significantly decreased μSBS for all substrates (p < 0.05). Comparison between BLII/ECII and SBU/RXU group showed no significant differences for enamel and resin blocks at 0TC (p > 0.05), but the BLII/ECII group exhibited higher SBS in the other groups (p < 0.05). Adhesive failure was the most frequently observed failure type across all groups. Conclusion: The adhesive performance on diverse dental substrates including enamel, dentin, zirconia, LDS, and resin blocks was notably affected by the selection of universal adhesive systems in combination with dual-polymerising resin cements that were applied. The BLII/ECII combination demonstrated long-term stable bonding performance for enamel, dentin, and zirconia. [ABSTRACT FROM AUTHOR]

In recent years, high esthetic expectations and natural appearance demands from patients have increased the popularity of ceramic restorations. The purpose of this study was to investigate the influence of restoration thicknesses and different resin cement brands on the translucency and final color of different types of monolithic zirconia and lithium disilicate ceramics. A total of 160 disc-shaped specimens (10-mm diameter; 1 mm, or 1.5 mm thick) were produced using different types of monolithic zirconia (Katana Zirconia UTML, Katana Zirconia ML, Katana Zirconia STML Blocks; Kuraray) and lithium disilicate ceramic (IPS e.max Press, Ivoclar Vivadent) (n = 40 discs per material, with 20 discs per thickness). Two different brands of dual-cured resin cements (RelyX Ultimate, 3M ESPE; and BisCem, Bisco) were applied to the specimen surfaces. The translucency and color changes of the lithium disilicate and monolithic zirconia ceramics were examined before and after cementation using a spectrophotometer. Within the limitations of this in vitro study, the resin cement brand and ceramic thickness variation influenced the translucency and final color of the monolithic zirconia and lithium disilicate ceramic specimens. [ABSTRACT FROM AUTHOR]

Background: Zinc-oxide eugenol (ZOE) cements are among the most used temporary materials in dentistry. Although ZOE has advantages over other temporary fillers, its mechanical strength is weaker, so researchers are working to improve it. E-glass fibers have emerged as promising reinforcing fibers in recent years due to their strong mechanical behavior, adequate bonding, and acceptable aesthetics. Objectives: To evaluate and compare the compressive strength, surface microhardness, and solubility of the ZOE and those reinforced with 10 wt.% E-glass fibers. Methods: A total of 60 ZEO specimens were prepared; 30 specimens were reinforced with 10 wt.% E-glass fibers, considered modified ZOE. The characterization of the E-glass fibers was performed by XRF, SEM, and PSD. The compressive strength, surface microhardness, and solubility were evaluated. Independent sample t-tests were used to statistically assess the data and compare mean values (P ≤ 0.05). Results: The results revealed that the modified ZOE showed a significantly higher mean value of compressive strength and surface microhardness while having a significantly lower mean value of solubility compared to unmodified ZOE (P ≤ 0.05). Conclusion: The modified ZOE with 10 wt.% E-glass fibers had the opportunity to be used as permanent filling materials. [ABSTRACT FROM AUTHOR]

Aim: Using a dip-coating technique, this study evaluated the microshear bond strength of resin cement to zirconia surfaces coated with nanosilica and nanoalumina. Methods: Zirconia blocks (n = 56) were categorized into seven groups based on surface treatment: untreated (control), tribochemical silica coating (positive control), dip coating with pure nanosilica, pure nanoalumina, and nanosilica-nanoalumina mixtures at 75:25, 50:50, and 25:75 volume ratios. The coated surfaces underwent characterization using a Scanning Electron Microscope (SEM), Energy Dispersive Spectroscopy (EDS), X-ray Diffraction (XRD), and Atomic Force Microscopy (AFM). Resin cylinders were cemented onto the treated zirconia surfaces, and microshear bond strength testing was performed. Differences in bond strength between groups were analyzed using One-way ANOVA and Tukey's post-hoc test (p < 0.05). Results: SEM revealed that nanosilica coatings formed island-like agglomerations, nanosilicananoalumina produced porous layers, and nanoalumina formed a dense cover layer. XRD detected only the tetragonal phase in coated zirconia, indicating no phase transformation compared to tribochemical silica coating. Microshear bond strength was higher for all coating groups than for controls (p < 0.05). The 75:25 nanosilica-nanoalumina demonstrated greater bond strength than other ratios. Conclusion: Dip-coating proved effective in enhancing resin-zirconia bonding without causing surface damage. Among the various ratios, the 75:25 nanosilica-nanoalumina mixture exhibited optimal bond strength. [ABSTRACT FROM AUTHOR]

To evaluate the effect of CAD/CAM materials surface treatments for bonding of different cementing systems on shear bond strength, including conventional and silane-containing resin cements, after 24 h and one year of water storage. Samples (12 mm × 6 mm × 1 mm) of each CAD/CAM material (IPS E.Max; Suprinity; Enamic; Cerec Bloc; IPS Empress) were divided into 4 groups: G1) 4.5% hydrofluoric acid (HFA) + silane + adhesive + RelyX Veneer (conventional); G2) HFA + Clearfil Ceramic Primer + Tooth Primer + Panavia V5 (conventional); G3) HFA + Panavia SA Cement Universal; G4) blasting with Al2O3 + Panavia SA Cement Universal. After the bonding procedures, two resin cement cylinders (1.5 mm × 1.5 mm) were constructed on each sample and tested after 24 h or one year of water-storage, using shear bond strength testing (n = 10). Data were submitted to generalized linear models' analysis (p <.05). The conventional treatment for glass ceramics with HFA and silanization or priming (G1 and G2) did not necessarily yielded higher bond strength than the simplified technique (G3 and G4). For IPS E.Max and Suprinity, all protocols had bond strength reduction after one year. For Enamic, Cerec Bloc and IPS Empress, G3 did not reduced statistically at one year. Panavia SA Cement Universal seemed not appropriate when IPS E.Max and Suprinity were blasted with Al2O3. On the other hand, the bond strength to etched or blasted with Al2O3 Enamic, Cerec Bloc and IPS Empress showed no difference or was higher than conventional luting protocols. [ABSTRACT FROM AUTHOR]

Background: This study aimed to investigate different surface treatments thought to increase the bond strength between zirconia ceramic and adhesive resin cement. Methods: The samples were prepared in 15 × 10 × 2 mm dimensions by cutting off monolithic zirconia ceramic blocks (Incoris TZI; Sirona, Germany). Surface roughness measurements were made with a profilometer, the average surface roughness (Ra1) was recorded, and five different surface treatments were applied. Group 1: Control group. No surface treatment was applied. Group 2: Sandblasted with Al2O3 under pressure of 50 μm. Group 3: Sandblasted with 30 μm Al2O3 - SiOx under pressure, then tribochemical silica coating, silane bonding agent, and ceramic primer were applied. Group 4: Samples were etched in a hot acid solution containing methanol, HCl, and chloride at 100 °C. Group 5: Samples were coated in a solution containing Grade C Aluminum Nitrite at 75 °C for 15 Sects. 12,000 thermal aging was carried out to all samples. Then, samples were bonded to a composite surface (Filtek Z250) with two different types of adhesive cement (Panavia F 2.0, Rely X U200) (n = 10). A load was applied to the samples attached to the Universal Test Device for the SBS, and the SBS was recorded. The surface roughness measurements of all samples were made again, and the average surface roughness Ra2 was recorded. The data was analyzed with a two-way ANOVA test. Bonferroni correction was used for multiple comparisons of the groups. p = 0.005 was accepted as the statistically significant value. Results: There was no statistically significant difference between the groups in the Ra1 measurements (p = 0.031). There was a statistically significant difference between the Ra2 values of Groups 4 and 5 and the Ra2 values of Groups 1,2 and 3 in the Ra2 measurements (p < 0.001). There was no statistically significant difference between the SBS values of the groups (p > 0.005). Also, there was no statistically significant difference in the SBS values of all groups for the two different cements tested (p > 0.005). Conclusions: None of the surface treatments applied to monolithic zirconia ceramic samples increased the SBS between ceramic and adhesive resin cement. [ABSTRACT FROM AUTHOR]

OBJECTIVE: To compare the shear bond strength (SBS) of orthodontic brackets bonded to three different types of ceramic surfaces (feldspathic, lithium disilicate, and zirconium) using Assure® Plus All and Transbond™ XT adhesives. MATERIALS AND METHODS: The sample comprised 72 monolithic computer‑aided design and computer‑aided manufacturing (CAD/CAM) ceramic samples that were randomly divided into six groups of 12 specimens each. Three groups (G1, feldspathic ceramic; G3, lithium disilicate ceramic; G5, zirconium surfaces) were bonded to metal brackets using Assure® Plus All adhesive, whereas the remaining three groups (G2, G4, G6; with the ceramic type in the same order as that in the previous groups) were bonded to metal brackets using Transbond™ XT. The samples were then subjected to 10,000 thermocycles. The SBS was calculated using the shear tests. The site of bonding failure was classified using the adhesive remnant index (ARI) score. One‑way analysis of variance (ANOVA) and Kruskal–Wallis tests were used for statistical analyses at a 5% significance level. RESULTS: Statistically significant differences were observed in the mean SBS values of the groups (P < 0.001). The mean SBS for G6 (zirconium plus Transbond™ XT) (2.52 MPa) was significantly lower than that for all other groups. Furthermore, statistically significant differences were found in the ARI score distribution among the groups (P < 0.001). Differences were identified between G6 and G3 (lithium disilicate Plus All Assure® Plus All) and G5 (zirconium plus Assure® Plus All). CONCLUSIONS: The mean bonding strength of brackets with Assure® Plus All was higher than that with Transbond™ XT for all three types of ceramics. However, all groups, except the zirconium plus Transbond™ XT group, showed acceptable bonding strength for orthodontic purposes. The application of hydrofluoric acid followed by silane and finally the Assure® Plus All adhesive system is adequate for bonding brackets to any of the ceramic tested surfaces. [ABSTRACT FROM AUTHOR]

Objective: We aimed to introduce the concept of "Selective adhesive luting—SAL" which is explained through clinical steps and supported by preliminary laboratory evidence. Clinical Considerations: Cementation with rubber dam is difficult to perform in case of short abutment teeth and/or subgingival crown margins. By means of universal resin cements/universal adhesive systems, which can be employed in self‐adhesive as well as adhesive luting procedures, this paper presents a novel technique allowing clinicians to perform reliable cementation where rubber dam isolation is difficult. The SAL technique entails the application of a universal adhesive system only on easily accessible abutment surfaces, enabling simultaneous adhesive and self‐adhesive luting in different portions of the abutment. The SAL clinical workflow is explained through prosthodontic rehabilitation of maxillary right central incisor affected by microdontia and restored with a lithium‐disilicate crown. Furthermore, our laboratory microshear bond strength study supports the rationale behind SAL application demonstrating higher bond strength even when the adhesive resin is placed only on one portion of the cementation substrate. Clinical Significance: This article advocates the application of SAL technique in clinical situations where effective adhesive luting is uncertain, since it can improve the adhesion between the tooth and universal resin cements. [ABSTRACT FROM AUTHOR]

Purpose: To assess and compare the impact of various computers aided design/manufacturing (CAD/CAM) materials on internal and marginal discrepancies, fracture resistance and failure probability of Endocrown restorations with 3D Finite Element analysis. Material and methods: Forty devitalized human maxillary first molars were collected. After endodontic treatment, they classified into 4 groups (n = 10) based on the materials used for endocrown fabrication. Group V (Vita-Enamic), Group N (Nacera Hybrid), Group T (Translucent Prettau Zirconia) and Group P (Pekkton ivory). All samples were exposed to artificial aging method simulating one year of clinical service. Silicone replica technique and stereomicroscope (25X) utilized to evaluate the marginal and internal gaps of endocrowns at different areas. Fracture resistance test used for cemented specimens followed by qualitative investigation utilizing Stereomicroscopy. Four models representing four endocrown systems used for restoration of severely-damaged endodontically treated upper first molar were generated for finite element analysis (FEA). Axially and centrally static occlusal compressive load was applied. Modified Von Mises and maximum principal stress values on the remaining tooth structure, cement lines and restorative materials were assessed independently. Resulted data were statistically analyzed at P-value ≤ 0.05. Results: In the current study, the highest mean values of internal and marginal discrepancies (μm) among studied groups were reported for Zirconia group (100.300 and 102.650) respectively, while the lowest mean value of internal discrepancy (μm) was observed for Nacera group (69.275) and the lowest mean value of marginal discrepancy (μm) was observed for PEKK group (78.4750). Regarding internal discrepancy, Vita-Enamic and PEKK groups did not exhibit any statistically significant differences (P = 0.293), however zirconia and the other tested groups exhibited statistically significant differences in the mean values of the marginal gap region (p 0.05).On the other hand, PEKK group showed the highest mean value of fracture resistance (1845.20 N) and the lowest value was observed for Vita-Enamic group (946.50 N). Regarding to stress distributions through 3D FEA, and according to modified von Mises (mvM) analysis, the greatest possible stress values were noticed in PEKK model in relation to tooth structure, cement line, and flowable composite as the following: (93.1, 64.5, 58.4 MPa) respectively, while Zirconia revealed lower maximum stress values (11.4, 13.6, 11.6 MPa) respectively. Conclusions: Statistically excellent marginal and internal fit was observed for PEKK in relation to other used endocrown materials. Also, PEKK material explained fracture resistance comparable to zirconia value while the lowest value was detected for Vita Enamic material. [ABSTRACT FROM AUTHOR]

Background: This study evaluated the effect of ceramic primers containing 10-methacryloyloxydecyl phosphate (10-MDP) and γ-methacryloxypropyl trimethoxysilane (γ-MPTS) agents on the shear bond strength (SBS) of CAD/CAM ceramics with different chemical structures and resin cement. Methods: A total of 640 CAD/CAM ceramic specimens were obtained from Vita Mark II (VM), IPS E.max CAD (EM), Vita Suprinity (VS) and Vita Enamic (VE). The specimens were divided into two groups: etched with hydrofluoric acid (HF) and unetched. Each group was treated with a different ceramic primer (Clearfil Ceramic Primer Plus, G-Multi Primer and Monobond S), except for an untreated group (n = 10). After ceramic primers and resin cement were applied to each ceramic surface, half of the specimens were thermally aged at 10,000 cycles, 5–55 ± 1 °C, with a dwell time of 30 s. The SBS was tested with a universal testing machine at a 0.5 mm/min crosshead speed. Data were analysed by using statistical software (SPSS 20). Normal data distribution was checked with the Shapiro‒Wilk test. Three-way ANOVA was used to analyse the difference between the numeric data of the HF etched and thermally aged groups. A post hoc Tukey test was applied in the paired comparison of significant difference. The statistical significance level was accepted as p < 0.05. Results: The highest SBS values were obtained in the HF etched G-Multi primer applied nonaged EM group (28.3 ± 2.62 MPa), while the lowest values were obtained in the nonetched and thermally aged EM group that received no treatment (2.86 ± 0.04 Mpa). The SBS significantly increased in all specimens on which the ceramic primer was applied (p < 0.001). Thermal ageing had a significant negative effect on the SBS values in all groups (p < 0.001). Conclusion: The positive combined effects of the 10-MDP and γ-MPTS agents resulted in a significant increase in the bonding strength of the resin cement to the CAD/CAM ceramics. In addition, the increase in the amount of inorganic filler provided a favourable effect on durable adhesion. [ABSTRACT FROM AUTHOR]

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Background: Evaluating the effect of different surface treatment methods on the micro-tensile bond strength (µTBS) of two different resin-matrix computer-aided design/computer-aided manufacturing (CAD/CAM) ceramics (RMCs). Methods: A standardized inlay preparations were performed on 100 intact maxillary premolars. According to the type of the restorative material, the teeth were randomly divided into two equally sized groups (n = 50): (polymer-infiltrated ceramic (Vita Enamic) and resin-based composites (Lava Ultimate)). The inlays were fabricated using CAD/CAM technology. In each group, the specimens were randomly assigned to five subgroups (n = 10) according to the surface treatment method: group 1 used was the control group (no surface treatment); group 2, was treated with air abrasion with 50 μm Al2O3 (A) and universal adhesive (UA); group 3, was treated with air abrasion with 50 μm Al2O3 (A) and silane coupling agent (S); group 4, was treated with hydrofluoric acid (HF) and universal adhesive (UA) and group 5, was treated with Hydrofluoric acid (HF) + silane coupling agent (S). The inlays were then cemented to their respective preparations using dual-cure self-adhesive resin cement (RelyX U200, 3 M ESPE) according to the manufacturer's instructions. The µTBS test was conducted in all groups, and stereomicroscope and scanning electron microscope were used to inspect the failure mode. The data were statistically analyzed using a two-way analysis of variance (ANOVA) and Tukey's post-hoc multiple comparison tests at a significance level of p < 0.05. Results: Surface treatments significantly increased the µTBS of the materials compared to the control group (p < 0.05). For CAD/CAM RBCs, the µTBS value highest in group 2 whereas, for PICN, the µTBS value was highest in group 3. Cohesive failure of CAD/CAM restorative material was the most predominant mode of failure in all treated groups, whereas adhesive failure at restoration-cement interface was the most predominant failure mode in the control group. Conclusion: Surface treatments increase the µTBS of resin-matrix CAD/CAM ceramics to tooth structure. Air abrasion followed by universal adhesive and hydrofluoric acid followed by silane application appears to be the best strategies for optimizing the bond strength of CAD/CAM RBCs and PICN respectively. [ABSTRACT FROM AUTHOR]

Objective: This study aims to evaluate and compare the film thickness obtained with a resin cement and two composite resins, preheated and/or ultrasonically vibrated, as luting agents. Materials and methods: One hundred and twenty‐six (126) pairs of resin discs were randomly assigned to six experimental groups (n = 21) according to luting agent (Variolink Esthetic LC, IPS Empress Direct or Estelite Omega) and cementation technique (preheating at 68°C and/or ultrasonic vibration). Specimens were luted by applying a controlled force. Following sectioning and film thickness measurement through field emission gun scanning electron microscopy, statistical analysis was carried out considering a 5% significance level. Results: Statistically significant lower film thickness was observed in Variolink Esthetic LC group when compared to all composite resin groups (p < 0.001), except IPS Empress Direct preheated and ultrasonically vibrated group (p = 0.073). IPS Empress Direct with ultrasonic vibration yielded statistically lower film thickness values than Estelite Omega groups, regardless of luting technique (p < 0.05). Ultrasonically vibrated Estelite Omega groups showed statistically lower film thickness values than solely preheated groups (p < 0.05). Conclusions: Both Variolink Esthetic LC and IPS Empress Direct preheated and ultrasonically vibrated provided the lowest film thickness. The addition of ultrasonic vibration during cementation proved to be effective in reducing film thickness of both tested composite resins. Clinical significance: The cementation technique will have variable results depending on the luting material. Adhesive cementation protocols with composite resins should mainly consider ultrasonic vibration, but also preheating, as strategies for reducing film thickness. The tested resin cement, alongside with IPS Empress Direct composite resin preheated and ultrasonically vibrated, provided the lowest film thickness among the tested materials and techniques. [ABSTRACT FROM AUTHOR]

To examine the effect of mold enclosure and chisel design on macro shear fatigue bond strengths of dental adhesive systems. The fatigue bond strength testing was conducted with two commercially available dental adhesive systems, (1) OptiBond eXTRa and (2) Scotchbond Universal, for bonding a resin composite (Filtek Supreme Ultra) to both enamel and dentin using a mold enclosure and a non‐mold enclosure with a knife‐edge and two sized notched‐edge chisel assemblies for loading. As a loading reference for the fatigue testing, macro shear bond strengths of the adhesive systems to enamel and dentin were conducted using a mold enclosure and a knife‐edge chisel assembly. The shear bond strengths with the mold enclosure using knife‐edge chisel assembly did not exhibit a significant difference between the adhesive systems for either enamel or dentin. The fatigue bond strengths of bonded specimens demonstrated significant differences when comparing the mold enclosure and non‐mold enclosure, but not between knife‐edge and notched‐edge chisel assemblies. The fatigue bond strengths of dental adhesive systems demonstrated significantly higher values when using mold‐enclosed bonded specimens than a non‐mold enclosure, regardless of type of chisel assembly. [ABSTRACT FROM AUTHOR]

Purpose: To evaluate the influence of different surface treatments of six novel CAD/CAM materials on the bonding effectiveness of two luting composites. Materials and Methods: Six different CAD/CAM materials were tested: four ceramics - Vita Mark II; IPS Empress CAD and IPS e.max CAD; Celtra Duo - one hybrid ceramic, Vita Enamic, and one composite CAD/CAM block, Lava Ultimate. A total of 60 blocks (10 per material) received various mechanical surface treatments: 1. 600-grit SiC paper; 2. sandblasting with 30-μm Al2O3; 3. tribochemical silica coating (CoJet). Subsequent chemical surface treatments involved either no further treatment (control), HF acid etching (HF), silanization (S, or HF acid etching followed by silanization (HF+S). Two specimens with the same surface treatment were bonded together using two dual-curing luting composites: Clearfil Esthetic Cement (self-etching) or Panavia SA Cement (self-adhesive). After 1 week of water storage, the microtensile bond strength of the sectioned microspecimens was measured and the failure mode was evaluated. Results: The bonding performance of the six CAD/CAM materials was significantly influenced by surface treatment (linear mixed models, p < 0.05). The luting cement had a significant influence on bond strength for Celtra Duo and Lava Ultimate (linear mixed models, p < 0.05). Mechanical surface treatment significantly influenced the bond strength for Celtra Duo (p = 0.0117), IPS e.max CAD (p = 0.0115), and Lava Ultimate (p < 0.0001). Different chemical surface treatments resulted in the highest bond strengths for the six CAD/CAM materials: Vita Mark II and IPS Empress CAD: S, HF+S; Celtra Duo: HF, HF+S; IPS e.max CAD: HF+S; Vita Enamic: HF+S, S. For Lava Ultimate, the highest bond strengths were obtained with HF, S, HF+S. Failure analysis showed a relation between bond strength and failure type: more mixed failures were observed with higher bond strengths. Mainly adhesive failures were noticed if no further surface treatment was done. The percentage of adhesive failures was higher for CAD/CAM materials with higher flexural strength (Celtra Duo, IPS e.max CAD, and Lava Ultimate). Conclusion: The bond strength of luting composites to novel CAD/CAM materials is influenced by surface treatment. For each luting composite, an adhesive cementation protocol can be specified in order to obtain the highest bond to the individual CAD/CAM materials. [ABSTRACT FROM AUTHOR]

This study aimed to investigate whether inorganic elements of polymer-infiltrated ceramic (PIC) and microfilled resin (MFR) for CAD/ CAM would affect initial bond strength to luting agent. Inorganic elements of PIC and MFR were different with shape and ingredient observed by SEM, STEM and EDS. Microtensile bond strengths (μTBS) value of PIC was increased by 10-methacryloyloxydecyl dihydrogen phosphate (MDP) and acetic acid (AA)- or MDP-activated silane treatment, and further increased by succeeding heat treatment (HT). The μTBS of MFR was increased by MDP and MDP-activated silane, but decreased by AA-activated silane without HT. The HT improved the μTBS of MFR with AA-activated silane, but conversely for MDP-activated silane. Only in MFR, phosphoric acid (PA) application before each surface treatment dramatically decreased the μTBS of AA-activated silane. FTIR peaks in MFR shifted according to phosphate group’s peak. MFR would possess high phosphate group adsorption capacity, with MDP effectively improving its bonding capability. [ABSTRACT FROM AUTHOR]

Background: An occurrence of secondary caries around the indirect restoration margin is reported to remain a leading cause of failures. Objective: This study aimed to test the interfacial microleakage of conventional glass-ionomer (CGI), resin-modified glass ionomer (RMGI) and Nano-hybrid composite (CR) restorations at a full veneer margin crown. Methods: Ninety human extracted molar teeth were divided into three groups (n = 30). Each group was subdivided into three subgroups (n = 10) according to the extent of the structural defects; The structural defect in G1 had a depth of 1.5 mm, width and length at 2 mm and 1 mm intrusion within the crown cervical margin. The corresponding structural defect dimension values for G2 were 2, 5, 4 and 2 mm with defects extending onto the root structure. Meanwhile, G3: structural deficiency of 2 mm depth, 3 mm width and 3 mm length and with 1.5 mm extension into the prepared teeth. These structural defects in each subgroup were restored with CGI, RMGI and CR. Artificial carious lesion formation was induced at the cervical finish line with a demineralizing solution. The artificial carious lesions were restored as per the group distribution. Subsequently, teeth samples were prepared and cemented with Nickel-chromium full coverage restorations utilizing glass-ionomer luting cement. Teeth samples were thermocycled, isolated with nail varnish, and immersed in 0.1% methylene blue for 24 h. The teeth samples were sectioned longitudinally, dye penetration was evaluated with a stereomicroscope. The data were analyzed with Kruskal-Wallis and Mann-Whitney U tests. Results: CGI-G1 recorded the highest micro-leakage score at 1.450; while CR-G3 recorded the least score (0.350). At a cementum-restoration interface, CR-G1 (0.850) documented the lowest micro-leakage; RMGI-G3 had a greater value at 1.700. Conclusions: The hybrid CR could be effectively used to restore the restoration of a marginal gap around crown margins. [ABSTRACT FROM AUTHOR]

Objectives: To address contemporary concepts in adhesive dental materials with emphasis on the evidence behind their clinical use. Overview Adhesive dentistry has undergone major transformations within the last 20 years. New dental adhesives and composite resins have been launched with special focus on their user‐friendliness by reducing the number of components and/or clinical steps. The latest examples are universal adhesives and universal composite resins. While clinicians prefer multipurpose materials with shorter application times, the simplification of clinical procedures does not always result in the best clinical outcomes. This review summarizes the current evidence on adhesive restorative materials with focus on universal adhesives and universal composite resins. Conclusions: (a) Although the clinical behavior of universal adhesives has exceeded expectations, dentists still need to etch enamel to achieve durable restorations; (b) there is no clinical evidence to back some of the popular adjunct techniques used with dental adhesives, including glutaraldehyde‐based desensitizers and matrix metalloproteinase inhibitors; and (c) the color adaptation potential of new universal composite resins has simplified their clinical application by combining multiple shades without using different translucencies of the same shade. Clinical Significance: New adhesive restorative materials are easier to use than their predecessors, while providing excellent clinical outcomes without compromising the esthetic quality of the restorations. [ABSTRACT FROM AUTHOR]

The main purpose of this study is to evaluate the influence of different types of ceramics and surface treatment methods on the shear bonding strength(SBS). Three different CAD/CAM ceramics were divided into 4 groups, respectively according to the following surface treatments: no treatment; etching with 4.5% HF acid; Nd:YAG laser irradiation; Nd:YAG laser followed by HF acid etching and then a silane-coupling agent and resin cement (Variolink N) were applied to each block. All specimens were stored in water for 24 h. Surface morphology of each specimen was evaluated and the SBS value was measured. The data were statistically analyzed by two-way ANOVA and LSD's multiple comparison test (p < 0.05). Among Celtra Duo, highest SBS values were obtained in NY groups (14.80 MPa), followed by NY + HF group and HF group; the significantly highest SBS values of IPS Empress CAD specimens were obtained in HF group (13.54 MPa) (p < 0.05) and the remaining groups were not observed significant differences (p > 0.05). Among IPS e.max CAD, the HF group (14.70 MPa) showed the highest bond strength, followed by NY + HF and NY groups. There were no significant differences between NY and NY + HF group (p > 0.05). Nd:YAG laser irradiation significantly improved the surface of Celtra Duo and IPS e.max materials, but this setting of Nd:YAG laser was not appropriate for IPS Empress CAD. [ABSTRACT FROM AUTHOR]

GIC is a dental restorative material which can be used as a filling material and as a luting cement. Nanotechnology is the use of systems, modifications and materials within the range of the nanometer scale. It is used to create more complex structures and better materials in a smaller scale which has better properties than the conventional type. Nanotechnology GIC can be formed by incorporation of nano fillers. Addition of nanoparticles can aid in improving the mechanical properties of the set GIC. The property of fluoride release is not affected by the addition of nanoparticles. This review focuses on the properties of nanotechnology GIC and how it differs from conventional GIC. The relevant articles were collected from various search engines including pubmed, google scholar and MESH within the timeframe of 2000 to 2020. The fluoride release of nano RMGIC is comparable to that of conventional RMGIC but lesser than conventional GIC cement. The property of fluoride release is comparative to that of conventional RMGIC. The nano RMGIC bonds as effectively as conventional GIC to the enamel and dentin but has considerably lesser bonding efficiency as compared with conventional RMGIC. It has a better flow than normal GIC. In conclusion, this study can aid in creating awareness about the newer technologies in the field of dentistry. Comparison of nanotechnology with conventional GIC would help in identifying the advantages and disadvantages of the newer techniques and create ideas to rectify the discrepancies. [ABSTRACT FROM AUTHOR]

This in vitro study aimed to evaluate the effect of two different polymer-based CAD/CAM materials,resin-nano ceramic (Lava Ultimate [LVU]) and composite (CERASMART [CS]), their different surface pre-treatments, and use of different resin cements on the μTBS of adhesively bonded CAD/CAM onlays to dentin. CAD/CAM materials were cut into slabs and divided into five groups according to the surface pre-treatments applied: Silane Primer, OptiBond XTR adhesive, Silane Primer+OptiBond XTR adhesive, Single Bond Universal (SBU), and RelyX Ceramic Primer+SBU. The LVU and CS specimens were bonded to the mid-coronal dentin of 50 non-carious human molars using NX3 resin cement with OptiBond XTR or RelyX Ultimate with SBU. μTBS was evaluated after 5,000 thermocycling and analysed with three-way-ANOVA and post-hoc Tukey's tests (p<0.05). The μTBS was significantly influenced by the type of CAD/CAM material (p<0.0001) surface pre-treatments (p<0.05) and resin cements (p<0.05). Regardless of the pre-treatments and resin cements, bonding of the composite CAD/CAM material to dentin was higher than the resin nano-ceramic material. [ABSTRACT FROM AUTHOR]

Although the effects of cigarette smoking on several dental problems have been widely studied, the association between tobacco exposure and resin-ceramic bonding is rarely reported. This study investigated the resin-ceramic adhesion (shear bond strength, SBS) and associated risk factors on three selected dental CAD/CAM ceramics using a novel model to simulate the exposure to cigarette smoking. Specimens from IPS e.max® CAD, Vitabloc® Mark II for Cerec and Zirconia Cercon were prepared and treated using silicacoating and silane. A layer of resin cement was applied on the treated ceramic surfaces and light activated. Specimens were placed in a chamber and challenged with various numbers of cigarettes (0, 1, 5, 10, and 15). Then, the specimens were subjected to SBS test and fractured surfaces were examined using scanning electron microscopy (SEM) and energy-dispersive X-ray spectrometry (EDX) to determine the failure mode and surface composition. Overall, the mean SBS of IPS e.max®CAD (9.6 ± 3.4 MPa), Vitabloc®Mark II for Cerec (9.3 ± 2.5 MPa) and Zirconia Cercon (8.7 ± 3.0 MPa) did not show any statistical significant difference (p = 0.192 > 0.05), such that the adhesion of resin bonded to glass-based ceramics (IPS e.max® CAD and Vitabloc® Mark II for Cerec) decreased with cigarette smoke exposure, but increased for the resin bonded to zirconia ceramic (Zirconia Cercon). Furthermore, the number of cigarettes has a statistically significant effect on the SBS (p = 0.001), such that in general 5 cigarettes yielded the lowest mean SBS (7.6 ± 2.1 MPa). SEM-EDX analyses showed mostly adhesive failures in all experimental groups with changes in surface morphology and chemical composition after smoking challenge. Cigarette smoking produces a different effect on resin-ceramic bonding depending on ceramic type that may be due to chemical reactions in the bonding interface and changes in temperature and moisture. Further work should explore the mechanism to which cigarette smoke affects the resin-ceramic bonding and its clinical relevance. [ABSTRACT FROM PUBLISHER]