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This article investigated the effects of airborne-particle abrasion and nanosilica (nano-Si) infiltration treatment on the surface characteristics of dental zirconia. A total of 15 unsintered zirconia ceramic green bodies (10 × 10 × 3 mm) were divided into three groups (n = 5): Group C, no treatment after sintering; Group S, airborne-particle abrasion with 50-µm aluminum oxide particles after sintering; and Group N, infiltration of nano-Si followed by sintering and hydrofluoric acid (HF) etching. The zirconia disks' surface roughness was analyzed by atomic force microscopy (AFM). The surface morphology of the specimens was analyzed using scanning electron microscopy (SEM), and the chemical composition was analyzed by energy-dispersive x-ray (EDX). Data were statistically analyzed by Kruskal-Wallis test (P < .05). Zirconia surface treatments by infiltration of nano-Si, sintering, and HF etching showed multiple changes in the surface features. The surface roughness of Groups C, S, and N were 0.88 ± 0.07 µm, 1.26 ± 0.10 µm, and 1.69 ± 0.15 µm, respectively. The surface roughness of Group N was significantly higher than that of Groups C and S (P < .05). EDX analysis showed peaks that corresponded to silica (Si) after infiltration with colloidal Si that disappeared following acid etching. Infiltrating nano-Si increases the surface roughness of zirconia. The formation of retentive nanopores on the surface potentially improves the zirconia-resin cement bonding strengths. [ABSTRACT FROM AUTHOR]

Objectives: The objective was to evaluate the polymerization efficiency of different bulk-fill resin-based composites cured by monowave and polywave light-curing units, by assessment of the degree of conversion and Vickers microhardness at different depths. Method and materials: Two commercially available bulk-fill resin-based composites were used: Filtek One Bulk Fill Restorative (3M ESPE) and Tetric N-Ceram Bulk Fill (Ivoclar Vivadent). The light-curing units utilized were two LED light-curing units: a monowave LED light-curing unit (BlueLEX LD-105, Monitex) and a polywave LED light-curing unit (Twin Wave GT-2000, Monitex). For each test, 20 cylindrical specimens (4 mm diameter, 4 mm thickness) were prepared from each bulk-fill resin-based composite using a split Teflon mold. Ten specimens were light-cured by the monowave light-curing unit and the other ten were light-cured by the polywave light-curing unit according to the manufacturer's recommendations. Attenuated total reflectance-Fourier transform infrared spectroscopy (ATRFTIR) was used to assess the degree of conversion, and a Vickers microhardness tester was used to assess Vickers microhardness. Statistical analysis was performed using three-way ANOVA and Tukey post-hoc tests (P < .05). Results: The degree of conversion and Vickers microhardness in bulk-fill resin-based composites containing only camphorquinone as photoinitiator were similar when cured with either monowave or polywave light-curing units. However, bulk-fill resin-based composites containing a combination of photoinitiators exhibited significantly higher degree of conversion and Vickers microhardness when cured with a polywave light-curing unit. Although all groups showed statistically significant differences between the top and bottom surfaces regarding degree of conversion and Vickers microhardness, all of them showed bottom/top ratios > 80% regarding degree of conversion and Vickers microhardness. Conclusion: The polywave light-curing unit enhanced the polymerization efficiency of bulk-fill resin-based composites especially when the latter contained a combination of photoinitiators, but does not prevent the use of a monowave light-curing unit. [ABSTRACT FROM AUTHOR]

Objectives: To evaluate the effect of sonic oscillation on penetration depth and marginal adaptation of resin-based fissure sealants. Method and materials: Thirty-six extracted human third molars were randomized into three groups: in the HF group, teeth were sealed with a filled-resin-based sealant (Helioseal F); in the Sonic-HF group, teeth were sealed with Helioseal F and subjected to sonic oscillation (Compothixo Device, 140 Hz vibration frequency and ± 150 µm amplitude) before curing; in the CO group, teeth were sealed with an unfilled-resin-based sealant (Clinpro). All teeth were thermocycled for 1,500 cycles at 5°C and 55°C, then sectioned buccolingually into four sections (mesial, two middle, and distal). Sections were evaluated under SEM for marginal adaptation and scored. For penetration depth, three independent measurements from each tooth were recorded under SEM, and data were subjected to statistical analysis. Results: The group subjected to sonic oscillation (Sonic HF) resulted in significantly superior penetration depth and marginal adaptation compared with the HF group, but with no significant difference compared with the CO group. Conclusions: Sonic activation of resin-based sealant increased penetration depth into fissures and marginal adaptation to the enamel wall without decreasing filler load or compromising sealant mechanical properties. [ABSTRACT FROM AUTHOR]

Purpose: This study aimed to investigate the bonding effectiveness of two HEMA/BPA-free universal adhesives (UAs) to flat dentin, to characterize their adhesive-dentin interfacial ultrastructure, and to measure their water sorption (Wsp), water solubility (Wsl), and hydrophobicity. Materials and Methods: The immediate and aged (50,000 thermocycles) microtensile bond strength (μTBS) to flat dentin of the HEMA/BPA-free UAs Healbond Max (HbMax; Elsodent) and Healbond MP (HbMP; Elsodent) as well as the reference adhesives OptiBond FL (Opti-FL; Kerr), Clearfil SE Bond 2 (C-SE2; Kuraray Noritake), and Scotchbond Universal (SBU; 3M Oral Care) was measured. The adhesive-dentin interfaces of HbMax and HbMP were characterized by TEM. Wsp and Wsl of all adhesive resins and of the primer/adhesive resin mixtures of HbMax, Opti-FL, and C-SE2 were measured. Hydrophobicity was determined by measuring the contact angle of water dropped on adhesive-treated dentin. Results: In terms of μTBS, HbMax and HbMP performed statistically similarly to Opti-FL and C-SE2, but outperformed SBU. Aging only significantly reduced the μTBS of SBU when applied in E&R bonding mode. TEM revealed typical E&R and SE hybrid-layer ultrastructures at dentin, while electron-lucent globules of unknown origin, differing in size and shape, were observed within the adhesive resin of HbMP and even more frequently in that of HbMax. Higher Wsp was measured for the primer/adhesive resin mixtures than for the adhesive resins. Opti-FL was more hydrophobic than all other adhesives tested. Conclusion: The HEMA/BPA-free UAs bonded durably to flat dentin with bond strengths comparable to those of the goldstandard E&R/SE adhesives and superior to that of the HEMA/BPA-containing 1-step UA. [ABSTRACT FROM AUTHOR]

Purpose: To assess the handling properties and clinical function of a new class of material, a so-called mineral-organic bone adhesive (Tetranite; TN), which as yet has no precedent in orthopedic or oral and maxillofacial surgery, for clinically unstable implants placed in immediate extraction sockets and immediately temporized in the anterior maxilla. Materials and Methods: A cohort of up to 15 patients requiring between one and four immediate dental implants placed into maxillary extraction sockets from canine to canine were eligible for inclusion. Implants had to be unstable with an insertion torque of < 15 Ncm. Implants were then stabilized using TN, which was allowed to set before reassessing stability using both torque and resonance frequency measurements. Implant stability quotients (ISQs) taken after TN setting were compared to ISQs taken prior to its application, and the implants had to demonstrate resistance to a forward torque of 20 Ncm to be considered stable. ISQs were monitored at 1 week and 1, 3, 7, and 12 months postplacement. In addition, peri-implant tissue health was monitored, adverse events were recorded, and implant success was determined at 1 year postplacement. Results: Eleven patients received a total of 14 implants. Three out of the first six implants failed within 1 month (50%), and thus a protocol amendment was made to remove steps considered potentially destructive to the bonding process. As a result of these amendments, only one further failure was experienced for the next eight implants placed (12.5%). Mean ISQ data averaged for buccolingual and mesiodistal measurements demonstrated a baseline value before TN application of 59.1 Ncm (SD: ± 9.7; range: 40.5 to 73.0). After final setting of the TN, mean ISQ measured 71.9 Ncm (± 6.5; 56.0 to 80.0). At 3 months, just prior to restoration placement, mean ISQ measured 71.0 Ncm (± 6.6; 57.0 to 78.0). Thereafter, the mean ISQ continued to increase at both the 7- and 12-month follow-ups with scores of 78.9 (± 4.6; 72.0 to 84.5) and 80.3 (± 3.8; 74.5 to 85.0), respectively. The surviving 10 implants went on to be fully restored and remained in function beyond the end of the study period to yield a final success rate of 71.4%. Conclusions: The purpose of a first-in-human study is to demonstrate an extrapolation of preclinical data into the controlled human clinical arena. It is an opportunity to learn what does and does not translate well from experimental data. In that regard, the current pilot study can be deemed a complete success. The implant survival rate of 71.4%, while disappointing, should be considered in light of the protocol amendments identified, the user handling experience learned, and the opportunity to modify the material to better perform in the human patient, as all represent important lessons learned. The notable increase in ISQ sheds light on the nature by which the glue was substituted for bone to yield a stable implant by the end of the study period. [ABSTRACT FROM AUTHOR]

To examine whether the effectiveness of current dentin-priming approaches requiring solvated hydrophilic resins may be replicated by modifying the infiltration dynamics of neat methacrylate-based monomers into dry-etched dentin using dimethyl sulfoxide (DMSO) pretreatments. Methods: H 3 PO 4 -etched mid-coronal dentin surfaces from human molars were air-dried for 30 s and randomly pretreated with 50 %(v/v) ethanolic DMSO for 20 or 60 s. Untreated samples and an isolated wet-bonding group served as controls. Samples were bonded with a three-step etch-and-rinse adhesive or simply with the solvent-free hydrophobic-rich resin. Restored crown segments (n = 7/group) were stored in distilled water for 24 h and sectioned for microtensile bond strength testing. Resin-dentin beams (0.8 mm2) were tested under tension until failure (0.5 mm/min) after 24 h or 2 years of storage in artificial saliva at 37 °C. Nanoleakage evaluation and hybrid layer characterization were performed by SEM. Bond strength data was examined by three-way ANOVA followed by Tukey and Dunnett's test (α = 0.05). Results: Pretreatments significantly affected the ability of neat and solvated resins to bond to etched-dry dentin (p = 0.001). Ageing significantly lowered bond strengths depending on resin composition and DMSO-application times (p = 0.007). While hybridization of DMSO-treated dentin with the solvated resin produced no significant reductions in bond strengths after ageing (p < 0.05) improving hybrid layer integrity, direct bonding of the neat hydrophobic-rich resin matched the long-term bonding performance of the "gold standard" wet-bonding protocol (p > 0.05). Significance : Lowering dentin's hydration state via DMSO-dry bonding allows direct coupling of neat methacrylate-based resins, which may contribute to developing new strategies to ultimately extend the durability of resin-dentin interfaces. [ABSTRACT FROM AUTHOR]

Background: Pulpal extension depth (PED) is critical for endocrowns restored teeth stability and longevity. There is a conflicting result regarding the minimum PED needed for the success of endocrowns. The aim of the current study was to compare Fracture resistance, failure mode, and restorability of CAD-CAM zirconia endocrowns with different pulpal extension depths bonded to maxillary molars. Materials and methods: Forty maxillary 1st molars were selected, decoronated, and randomly divided into 4 main groups (n = 10) according to the PED measured from the pulpal floor to the occlusal end of the wall height into; group D2, PED was 2 mm, group D3, PED was 3 mm, group D4, PED was 4 mm, group D5 PED was 5 mm. Teeth were prepared and secured in resin dies with pseudo periodontal ligament. Specimens from all groups were individually scanned using an intra oral digital scanner. Monolithic zirconia endocrowns were constructed and bonded to their corresponding. Following thermal cycling, each specimen was axially loaded in a universal testing machine at a 0.5 mm/min crosshead speed. Failure modes were inspected, and restorability of specimens was recorded. Data was collected, tabulated, and statistically analyzed. Results: Descriptive statistics displayed higher mean value of the D2 group (3657 1673.8 N) followed by the D3 group (3009.3 853.5 N), then the D4 group (2087.3 413.9 N) and finally the D5 group (1972.7 ±330.4 N). At a 95% confidence level, one-way analysis of variance (ANOVA) revealed significant differences between tested groups. (P = 0.014). Regarding failure mode, D2 recorded 100% restorable failures, followed by D3 (90%) and D4 (60%), while the least was D5 (50%). Conclusions: Endocrowns with 2 mm PED recorded the highest fracture resistance and the highest restorable failure modes. Endocrowns with 5 mm PED recorded the lowest fracture resistance and the lowest restorable failure modes. Tall walls should be shortened during the preparation of endocrowns in maxillary molars. [ABSTRACT FROM AUTHOR]

Background: Hydrophilic monomer 2-hydroxyethyl methacrylate (HEMA)-free adhesive systems are gaining increasing popularity nowadays. Although the addition of HEMA to dental adhesives improves dentin wettability and resin diffusion into demineralized collagen fibrils, HEMA's high hydrophilicity can lead to hydrolytic degradation of the adhesive interface. Thus, HEMA-free adhesive systems have been developed. Unfortunately, the lack of HEMA in the adhesive composition may lead to a separation phase between hydrophobic and hydrophilic components. The aim of this systematic review was to evaluate the clinical performance of HEMA-free adhesive systems and compare them with HEMA-containing ones. Methods: An electronic search of The National Library of Medicine (MEDLINE/PubMed) was conducted. Eligibility criteria were reporting empirical data from clinical studies published between 2013 and 2023 about the clinical performance of HEMA-free adhesive systems for direct resin composite restorations. Studies with at least 2-year clinical follow-up done in permanent dentition in any form of cavities were selected. The included studies were assessed for risk of bias using the modified Cochrane Collaboration tool criteria. Results: The database search returned 147 studies; a total of 7 studies were included in this review; the majority of studies reported no significant difference between the two types of adhesives for the parameter of retention. Conclusions: HEMA-free adhesive systems exhibited good clinical performance with regard to retention. There was some concern about their influence on marginal adaptation and marginal discoloration due to the conflicted results reported by the included trials. Thus, the results need to be confirmed with long-term evaluations. Systematic review registration: PROSPERO CRD42023448952. [ABSTRACT FROM AUTHOR]

Background: Short dentin etching, a relatively recent technique, aims to improve resin-dentin bonding by preserving hydroxyapatite crystals within the collagen spaces. This study explores short dentin etching's potential in mitigating over-etching issues in deep proximal dentin/cementum margins, an aspect not previously investigated. This study evaluates the microtensile bond strength (μTBS) and marginal adaptation of two universal adhesives using different etch-and-rinse strategies (15-second and 3-second etching) and self-etch strategies, both immediate and post-thermal cycling and mechanical loading. Methods: Eighty-four molars underwent μTBS testing, categorized by the universal adhesive type (Tetric Uni and Prime&Bond Uni) (n = 42) and adhesive strategy (n = 14) with half tested after 24 h and the rest post aging. Forty-two molars received occluso-mesial preparations with proximal margins in dentin/cementum and were restored accordingly. Scanning electron microscope (SEM) examination of epoxy replicas for the restoration/gingival dentin interfaces was conducted after 24 h and aging. Dentin etching patterns were assessed using SEM. A three-way ANOVA evaluated μTBS data, while a two-way ANOVA and paired sample t-test analyzed marginal adaptation data (significance level is α = 0.05). Results: Adhesive type, strategy, and aging significantly influenced μTBS. After aging, Tetric Uni subgroups displayed higher bond strength compared to Prime&Bond Uni subgroups. Marginal adaptation was unaffected by adhesive type or strategy, although aging reduced bond strength and adaptation for both adhesives. Conclusions: The etch-and-rinse protocol yielded higher μTBS results for the HEMA-free isopropanol-based adhesive (Prime&Bond Uni). Marginal integrity was similar for both adhesives. The 3-second and 15-second etching times produced consistent results in all tests and for both adhesives. Clinical significance: The adhesive protocol for bonding universal adhesives to dentin is contingent on the adhesive composition. [ABSTRACT FROM AUTHOR]

Background: Repairing composite resins is a less invasive alternative to complete restoration replacement. To achieve a successful bond between the existing and newly applied composite materials, various surface preparation methods, such as sandblasting and acid etching, have been explored. The aim of the study was to evaluate the effect of different surface treatments on the repair bond strength of a universal nanohybrid composite resin restorative material before and after thermal aging, by utilizing a micro-shear bond strength (µSBS) test. Methods: For the micro-shear bond strength test, a total of 120 cylindrical (3mmX2mm) nanohybrid resin based composite specimens were prepared. The prepared specimens were divided into three groups (n = 40/per group) based on surface treatment methods: a non-aged group, 10,000 thermal cycle aging and 50,000 thermal cycle aging. The aged and non-aged specimens were further divided into four groups according to adhesive application modes and surface pretreatment methods: 1.universal adhesive/self-etch mode, 2.aluminum oxide sandblasting + universal adhesive/self-etch mode, 3.universal adhesive/etch-and-rinse mode, 4.aluminum oxide sandblasting + universal adhesive/etch-and-rinse mode. Subsequently, 0.8mmX2mm disc shape light cure resin based composite specimens were applied with a direct placement technique on the treated surfaces of all samples for repair. µSBS test was performed using a universal testing machine at a crosshead speed of 1 mm/min. Kruskal-Wallis and Mann-Whitney tests were performed for statistical analysis. Results: The µSBS values of the non-aged group were higher than those of the 10,000 and 50,000 thermal cycle groups, with no significant differences within the non-aged subgroup (p > 0.05). In the aged groups, significant differences were observed between adhesive application modes and surface treatments. Specifically, the etch-and-rinse mode showed higher bond strengths than the self-etch mode after 50,000 thermal cycles (p < 0.05). Sandblasting combined with universal adhesive (self-etch mode) improved bond strength, especially in the 10,000 thermal cycle group (p < 0.05). Conclusion: Aging reduced the bond strength of composite resin repairs, with the etch-and-rinse mode outperforming the self-etch mode in aged specimens. Sandblasting alone did not enhance bond strength. These findings highlight the importance of considering aging and adhesive strategies to optimize repair outcomes, with further research needed on long-term durability. [ABSTRACT FROM AUTHOR]

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]

Background: This study aimed to assess the influence of different pretreatment protocols and antioxidants application on the shear bond strength (SBS) of universal adhesive to sound (SoD) and caries-induced dentin (CID). Methods: One hundred and twenty posterior teeth had their occlusal enamel removed, then the specimens were divided into two main groups according to dentin substrates; SoD and CID, three subgroups according to pretreatments protocols control (no pretreatment), NaOCl-treated, and Er, Cr:YSGG-treated and two divisions according to antioxidant application (with and without sodium ascorbate (SA) application). All-Bond Universal (ABU) universal adhesives was applied in self-etch (SE) mode then resin composite discs were built. The specimens were stored in distilled water for 24-hr at 37°C before SBS testing. Three-way ANOVA and Tukey HSD tests were used for data analysis (a = 0.05). Results: 6% NaOCl resulted in a significant reduction in SBS in SoD without antioxidant application. 10% SA application showed significant increase in SBS for 6% NaOCl group only in SoD. Laser application recorded a significantly higher SBS compared to 6% NaOCl group without or with antioxidant application, while 10% SA application revealed a significant increase in SBS for control group only. Conclusions: Er, Cr:YSGG laser irradiation followed by antioxidant application has the potential to enhance the bonding quality of both tested dentin substrates. NaOCl application has significantly compromised the bonding to SoD and CID substrates. [ABSTRACT FROM AUTHOR]

Background: Conservative dentistry introduced modern restoration designs, contributing to the greater use of partial-coverage ceramic restorations. New strong bondable ceramic materials made fabricating partial coverage ceramic restorations easier to restore the badly destructed teeth. Aim of the study: This study investigated the impact of three distinct overlay preparation designs on the marginal fit (both before and after thermal aging) and the fracture resistance of overlay restorations fabricated using advanced zirconia-reinforced lithium disilicate (ALD) CAD/CAM glass-ceramic blocks. Materials and methods: Using a standardized preparation protocol, three typodont molars were prepared to receive three different indirect overlay ceramic restoration designs. The typodont teeth were duplicated to get 27 resin dies that were randomly allocated into three groups (n = 9) based on the preparation design; group (O): a traditional overlay preparation with anatomical occlusal reduction, group (OS): anatomical occlusal reduction with circumferential shoulder finish line, and group (OG): anatomical occlusal reduction with a central groove preparation at the mid-occlusal surface. After standardized restorations fabricated following the manufacturer's guidelines, the restorations were cemented to their corresponding dies and exposed to thermal aging corresponding to 6-month clinical service. Marginal gap was measured before and after thermal aging procedure using an optical microscope. To measure fracture resistance, specimens were loaded till failure using the universal testing machine. The Kruskal Wallis test was utilized to assess data among the groups, followed by Dunn's post hoc test with Bonferroni correction. Differences in the marginal fit before and after thermal aging were evaluated using Wilcoxon Sign Rank test. Results: A statistically significant difference in marginal fit was observed between the studied groups, with a p-value of 0.032 where group OS has the lowest micro gap compared to group OG and group O. The fracture resistance group (O) recorded the highest fracture resistance with a statistically significant difference between the studied groups at p value = 0.043. Conclusions: Adjusting the tooth preparation significantly influenced both the fracture resistance load and the marginal fit observed for advanced zirconia-reinforced lithium disilicate glass-ceramic (ALD) overlays. [ABSTRACT FROM AUTHOR]

Polyetheretherketone (PEEK) has emerged as a revolutionary material in modern dentistry because of its unique combination of mechanical strength, biocompatibility, and versatility. This literature review examines the current applications and future potential of PEEK in various dental disciplines. PEEK's favorable properties, including its low specific weight, high strength-to-weight ratio, and ability to be easily machined, have led to its adoption in prosthetics, implantology, and dental esthetic restorations. This material has shown promise for fabricating crowns, bridges, removable partial denture frameworks, and implant components. PEEK's radiolucency and bone-like elastic modulus make it particularly suitable for dental implants and abutments. Additionally, its resistance to degradation and compatibility with various surface treatments enhances its long-term performance in the oral environment. While challenges such as bonding to other dental materials and aesthetic limitations exist, ongoing research is addressing these issues through surface modifications and composite formulations. As the dental field continues to evolve, PEEK's adaptability and biocompatibility position it a key player in the development of next-generation dental materials and techniques, potentially transforming patient care and treatment outcomes in dentistry. [ABSTRACT FROM AUTHOR]

Objective To evaluate the effect of silane-free universal adhesives systems on the repair shear bond strength (SBS) of sonic-activated bulk-fill [SonicFill (SF) Kerr, USA] composite applying additional silane in the repair of bulk-fill composite. Methods Sonic-activated bulk-fill composite samples (n=40) were prepared using a teflon mold (6 mm x 4 mm) and polymerized. Then all samples were kept in an incubator to simulate the aging process at 37 °C for one month. Aged composite samples were embedded in acrylic resin. For the repair, the specimen surfaces were roughened with a diamond bur. They were divided into 2 groups (n=20) according to the adhesive system used and then into two subgroups (n=10) as additional silane was applied or unapplied. Adhesive systems Ambar Universal Bond (AUB), (FGM, Brazil), G-Premio Bond (GPB) (GC, USA) and silane (G-Multi primer GC, Tokyo, Japan) were applied according to the manufacturer's instructions. Samples were subjected to a shear bond test in a universal testing device. For statistical analysis, one-way ANOVA test was performed (p<0.05). Results The highest SBS value was obtained in the silane-treated AUB group (21.88±6.4), while the lowest SBS value was obtained in the silane-treated GPB group (16.07±6.2). No statistically significant difference was observed between all groups (p<0.05). Conclusion Additional silane application does not affect the SBS of universal adhesives on an SF composite material. Keywords:Bulk-fill composite repair, sonic-activated bulk-fill composite, surface treatments, silane agent, universal adhesive: [ABSTRACT FROM AUTHOR]

Objective: This randomized controlled trial compared the 1-year clinical efficacy of Scotchbond Universal Adhesive Plus (SBU+) with that of its predecessor Scotchbond Universal Adhesive (SBU) to restore Class I and Class II preparations using the self-etch strategy in adult patients. Materials and methods: Fifty-one subjects participated in this study. Two posterior teeth in each subject were randomized to a restoration with SBU+ or to a restoration with SBU (control) using the self-etch strategy. Teeth were restored with Filtek Universal Restorative. Restorations were evaluated at baseline, 6 months and 1 year using the FDI criteria. The Wilcoxon signed-rank test was used to compare outcomes. Results: No restorations were graded as “Insufficient/Unsatisfactory” or “Poor” for any of the FDI criteria at the baseline, 6-month, or 1-year visits. At 1 year the retention rate was 100% for both SBU+ and SBU. For fracture of the restorative material 42/44 SBU+ restorations (95%) and 44/44 SBU restorations (100%) were graded “Excellent/Very Good” (p > 0.05). All restorations were clinically acceptable for marginal adaptation at 1 year with no statistical differences between the two adhesive materials. There were no recurrent caries lesions at the 1-year visit. Conclusions: The clinical efficacy of the SBU+ at 1-year was not different to that of its predecessor SBU in Class I and Class II restorations of adult patients using the self-etch strategy. Clinical relevance: The two dental adhesives used in this clinical trial showed excellent results in posterior restorations at 1 year without using a separate phosphoric etching step. [ABSTRACT FROM AUTHOR]

Root-filled, cracked or very weak back teeth pose perennial problems for patients and dentists alike. A biologically sensible and perhaps unorthodox approach to create occlusal clearance is by adding direct resin composite pragmatically to the biting surfaces of various other much sounder teeth. Doing additive bonding first loads those sounder teeth preferentially, without damaging them, while creating 'adequate' clearance space between the occlusal surface of the structurally compromised back tooth and its opponents during all jaw movements. Once the space is gained over the occlusal aspects of that root-filled tooth (or other cracked or weak teeth), it is kept by immediately bonding some strikingly different-coloured restorative material onto the strongest part of its occlusal surface at that same visit. The empirical composite devices that are bonded on to the chosen stronger teeth are maintained in position during the adaptation period by the patient to their pragmatic new occlusion, but they are modifiable, if that is ever required. Their adaptation to this new occlusion can be verified easily with the patient prior to making them a cuspal-coverage protective restoration for their weak tooth. At any mutually convenient time afterwards, simply grinding off the obviously contrasting-coloured composite off the weak tooth provides most of the occlusal space required for that cuspal-coverage restoration, but without having to remove significantly more sound tooth tissue to achieve that outcome. CPD/Clinical Relevance: A pragmatic approach to create occlusal clearance for structurally compromised premolars and molars is described. [ABSTRACT FROM AUTHOR]

Inadequate marginal sealing in endodontically treated teeth can lead to microleakage and treatment failure. The purpose of this in vitro study was to quantify and compare the quality of the marginal seal when different materials and bonding techniques were used to restore endodontic access cavities in zirconia cylinders. Fifty custom zirconia cylinders (10.0 mm in diameter x 14.0 mm in height; wall thickness of 1.5 mm) were prepared with simulated endodontic access cavities (5.0 mm in diameter). The cylindrical specimens were divided into 5 groups, each assigned a different method of access cavity restoration (n = 10 per group): direct glass ionomer cement restorations; direct composite resin restorations adhesively bonded without prior aluminum oxide (AI2O3) particle abrasion of the zirconia surface; direct composite resin restorations adhesively bonded after AI2O3 particle abrasion of the zirconia surface; custom zirconia inlays adhesively bonded without AI2O3 particle abrasion of the zirconia surface or inlay; and custom zirconia inlays adhesively bonded after AI2O3 particle abrasion of the zirconia surface and inlay. Specimens were immersed in 2% methylene blue solution and stored in a humidified incubator at 37°C, and dye penetration was quantified with a spectrophotometer (at 450 nm) every 7 days for 28 days. Statistical analysis was conducted using 2-way analysis of variance with the Tukey test and chi-square analysis. Statistically significant differences in dye penetration were observed, with microleakage influenced by the restoration material and bonding protocol. Zirconia inlays placed after AI2O3 abrasion exhibited the least leakage, showcasing significantly superior sealing compared with direct composite resin restorations without AI2O3 abrasion. The results indicated that AI2O3 particle abrasion is essential for secure bonding of restorations to zirconia. The results of the study confirm that glass ionomer cement should be avoided for long-term restoration of access cavities in zirconia restorations due to its inferior microleakage prevention. Instead, composite resins and zirconia are favored, with AI2O3 air abrasion showing the potential to enhance marginal seal in endodontically treated teeth. [ABSTRACT FROM AUTHOR]

To evaluate the effect of adhesive coats application on the enamel microtensile bond strength (µTBS) of universal adhesives, morphological etching pattern and their chemical interaction with hydroxyapatite (HA). Two universal adhesives were investigated: Scotchbond Universal (SBU, 3 M) and Prime&Bond Universal (PBU, Dentsply). The adhesives were applied in self-etching mode on bovine enamel (n = 8) in one (1L), two (2L) or three coats (3L) and light-cured as per manufacturers' instructions. As controls adhesives were applied to etched enamel (H3PO4-37% phosphoric acid). Bonded specimens were cut into sticks that were stored in deionized water for 24 h or 6 months prior to µTBS testing. Two-way ANOVA and Tukey's test were used for statistical analysis of bond strength with α = 5%. For morphological SEM analysis, enamel surfaces were treated as aforementioned and immediately rinsed with acetone. The intensity of monomer-calcium salt formation from each treatment was measured via infrared spectroscopy (ATR-FTIR). All treatments presented no significant reduction on µTBS after aging (p > 0.05). However, SBU attained highest µTBS when applied in 3L. PBU showed higher µTBS when applied to H3PO4 etched enamel than 1L or 2L. Etching pattern was enhanced by 3L application, particularly with PBU. Chemical interaction was notably higher for SBU than PBU, with no relevant differences with more layers or prior H3PO4-etching. The application of three adhesive coats of universal adhesives in self-etch mode using may enhance the bonding performance and etching pattern to enamel, surpassing the H3PO4-etched enamel bond for SBU. The chemical interaction with calcium from enamel is not affected by number of coats or prior phosphoric acid etching. [ABSTRACT FROM AUTHOR]

Background: The fracture of an endodontic instrument within the root canal system can occur during root canal therapy, complicating thorough cleaning and shaping. Consequently, managing the broken fragment becomes crucial. Methods: Eighty Nickel-titanium (NiTi) #20 K-files (Mani, Tochigi, Japan) were cut 8 mm from the tip, fixed into a corkboard, and classified into five groups (n = 14 each). The microtube-based methods included: microtube with cyanoacrylate glue (group 1), light-cured flowable composite resin (group 2), wire (group 3), internal shaft (group 4), and laser (group 5). Each method grasped the separated instrument's free end above the corkboard, and a pull-out test was performed using a universal testing machine(UTM). Additionally, 10 samples were separated in extracted canine root canals, and the temperature of the outer surface of the root was measured using the microtube and laser methods. Results: Groups 1 and 4 exhibited significantly greater pull-out force compared to the other groups (p < 0.001). Groups 2 and 5 demonstrated significantly lower pull-out forces (p < 0.001). In Group 5, the temperature increase was 11 °C on the tube surface and 3 °C on the root surface. Conclusion: All microtube-based techniques are effective for fractured instrument removal, with cyanoacrylate glue and laser methods being particularly suitable for cases that require higher force. [ABSTRACT FROM AUTHOR]

Background: According to anecdotal reports, SDF's ability to arrest caries can be enhanced by light-curing in a clinical setting. The purpose of the present study was to explore the dental professionals' perceptions of using SDF and to understand the barriers and enabling factors to using SDF with and without light-curing. Methods: A qualitative study was conducted with dental professionals who had experience with using SDF with and without light-curing. A purposive heterogeneous and convenience sampling approach was applied to ensure the inclusion of participants with different employment and experience levels. Eighteen participants (dental students (undergraduate and postgraduate), dental personnel (practicing dentists and dental hygienists), and academics) with ages ranging from 22 to 53 years old participated in the study. The data were collected through a semi-structured open-ended questionnaire. Manual line-by-line coding and content analysis methods were used for data analysis. Results: Most participants indicated a preference for light-curing, citing perceived benefits, such as quicker treatment, convenience, better visibility, prevention of saliva contamination, and ensuring thorough SDF coverage. However, some participants voiced concerns, based either on existing practice guidelines or due to insufficient evidence regarding the efficacy of light-curing. Additionally, one participant proposed a hybrid approach based on tooth location, suggesting avoiding using light-curing on anterior teeth, while utilizing it on posterior teeth. Conclusion: The participants' responses indicated that the use of SDF with and without light-curing each has its merits. Using SDF with light-curing emerged as the preferred method due to perceived benefits. e.g., quicker treatment, better moisture control. However, concerns regarding existing guidelines and the lack of robust evidence for its efficacy were also identified. This study highlights the need for additional research to address the knowledge gaps and provide stronger evidence to support the use of light-curing after SDF application. [ABSTRACT FROM AUTHOR]

Objective: To evaluate the shear bond strength (SBS) and adhesive remnant index (ARI) scores of metal brackets to glazed lithium disilicate reinforced glass-ceramics and zirconia according to various surface treatment protocols. Methods: A total of 240 lithium disilicate ceramic (LD) and 240 zirconia (Zr) blocks were randomly divided according to sandblasting, hydrofluoric acid (HF) etching, universal primer use, and the adhesive system applied. A maxillary canine metal bracket was bonded to each sample with resin cement (Transbond XT, TXT). SBS tests and ARI score analysis were performed. Four-way ANOVA followed by Tukey's post hoc test was used for SBS differences, and Fisher's exact test was used for the ARI scores (p < 0.05). Results: All groups combining a universal primer with a universal adhesive with and without sandblasting provided satisfactory SBS values for both LD and Zr. Fractures of the samples were observed only for LD in the groups combining HF with universal primers and universal adhesives with and without sandblasting. Conclusions: Combining a universal primer with a universal adhesive could be recommended for orthodontic bonding to both LD and Zr. Regarding their risks (i.e., damaging the restoration surface or burning the oral tissues), sandblasting or HF might not be necessary despite the presence of glaze covering the ceramic surface. [ABSTRACT FROM AUTHOR]

Background: The clinical performance of dental materials can be predicted via artificial aging approaches. The bracket bonding procedure may cause irreversible alterations to the enamel surface. The aim of this study was to introduce a novel artificial aging protocol and evaluate its effect on the discoloration of both bracket-bonded and unbonded teeth while also comparing the effects of four orthodontic adhesives on enamel color and whiteness. Methods: One hundred permanent lower incisors from humans were randomly divided into five groups, each including 20 specimens. The lower incisor metal brackets were bonded to the teeth via four different orthodontic adhesives (Transbond XT, Kurasper F, Bisco ORTHO, and Light Bond), and a control group was established. To simulate the cumulative effects of aging on the oral cavity, all the samples were subjected to mechanical cyclic loading (50,000 cycles), hydrothermal cycling (10,000 cycles), or exposure to stained beverages (25 days). A colorimeter device was used to measure the color of the teeth before and after testing. Statistical differences were calculated via one-way analysis of variance (ANOVA) and Tukey's test. Results: The combined aging protocol resulted in statistically significant and clinically unacceptable differences in tooth color alterations and whiteness index values across all groups (p < 0.05). The control group presented the least significant discoloration, whereas the bracket-bonded groups presented greater discoloration. Furthermore, there were statistically significant differences among the bracket-bonded groups (p < 0.05). Conclusions: The combined artificial aging protocol can be employed to simulate the macroenvironmental conditions of the oral cavity in laboratory investigations. The composition of the orthodontic adhesive also influences the severity of tooth discoloration. [ABSTRACT FROM AUTHOR]

Background: Achieving a stable bond with zirconia requires mechanical and chemical bonding methods. Information regarding the optimal treatment method for zirconia with varying yttrium content is scarce. This study evaluated the effect of different surface treatments on the shear bond strength of zirconia with various yttria contents. Materials and methods: A total of 168 disc-shaped zirconia specimens were classified into 12 groups based on the surface treatment method, including airborne-particle abrasion (APA), selective infiltration etching (SIE), hot etching (HE), and control group with no treatment; and yttria contents including Zolid Zi (4.5–5.6 wt% yttrium), Zolid HT White (6.7–7.2 wt% yttrium), and Ceramill Zolid FX (9.15–9.55 wt% yttrium). The surface roughness (Ra and Rz) of the specimens and the shear bond strength was measured (α = 0.05). Results: The results indicated that the mean bond strength of all specimens was higher after different surface treatments compared to the control group, of which the APA method resulted in higher bonding strength in all kinds of zirconia than other methods (P < 0.05). In all types of zirconia, a significant difference was observed in surface roughness (Ra and Rz) resulting from various surface treatment methods (P < 0.001). Interaction of surface treatment methods and zirconia type significantly affected shear bond strength and surface roughness (P < 0.05). Conclusion: APA significantly enhanced shear bond strength and surface roughness across all zirconia types and yttria contents. The SIE and HE methods also showed promising results. Zolid Zi showed superior bond strength, whereas Zolid FX demonstrated reduced bond strength. [ABSTRACT FROM AUTHOR]

Pre-etching ceramic restorations in dental laboratories is preferred by numerous dentists due to the potential health concerns associated with handling hydrofluoric acid (HF) if not managed correctly. This study aimed to evaluate the effect of different surface treatments on the shear bond strength (SBS) between lithium disilicate ceramics and self-adhesive resin cement. For this study, a total of 60 IPS e. max CAD (Ivoclar Vivadent) lithium disilicate specimens were prepared. Specimens were randomly divided into six groups, with 10 specimens per each. Different surface treatments were applied (1: Control group no surface treatment (C); 2: 10% hydrofluoric with silane coupling agent (HFS); 3: 10% hydrofluoric acid only (HF); 4: Sandblasting with 50 μm aluminum-oxide powder (AO); 5: Sandblasting with 30 μm silica-coated aluminum-oxide powder (SC), and 6: Er,Cr:YSGG laser (L). SBS tests were performed, and data analyzed using one-way ANOVA and Tukey's multiple comparisons. The difference between the mean average of SBS was statistically significant among all different surface treatments (p ≤ 0.05) except for the L group with a (p = 1.00). The highest mean value was observed in the HFS followed by the HF group. Whereas the L group showed no statistical significance in comparison with the C group (p > 0.05). Hydrofluoric acid etching in combination with a silane coupling agent was the most effective surface treatment for bonding lithium disilicate ceramics with resin cement. In contrast, laser irradiation was the least effective among all other groups. [ABSTRACT FROM AUTHOR]

Introduction: Ensuring strong adhesion of composite resin to dentin requires isolation, as moisture contamination from gingival fluid, blood, or saliva can weaken the bond. This can lead to microleakage, restoration loss, recurrent caries, postoperative sensitivity and discolouration. Long-lasting restorations are crucial in adhesive dentistry, but contamination often results in adhesion failure. To restore bond strength, various decontamination procedures are recommended. Aim: To evaluate and compare the effects of different contaminants and ethanol decontamination on the shear bond strength of one-step self-etch versus universal adhesives to dentin. Materials and Methods: This in-vitro study, conducted in the Department of Conservative Dentistry and Endodontics at Sibar Institute of Dental Sciences in Guntur, Andhra Pradesh, India, from July 2023 to October 2023, utilised the buccal surfaces of 70 human molars. The molars were divided into two groups (n=35): Group 1 - One-step self-etch adhesive and Group 2 - Universal adhesive. Each group was further subdivided into five sub-groups (n=7): Control (Subgroup A), Saliva contamination (Subgroup B) Blood contamination (Subgroup C) Saliva contamination followed by ethanol decontamination (Subgroup D) and Blood contamination followed by ethanol decontamination (Subgroup E) followed by ethanol decontamination. A plastic tube loaded with composite resin was placed over the dentin surface and light-cured. Shear bond strength at the dentin-composite interface was evaluated using a Universal Testing Machine (UTM). One-way Analysis of Variance (ANOVA) for intergroup comparison followed by Tukey's post-hoc test for multiple comparisons was performed. Differences were considered significant at p-value ≤0.05 between groups. Results: The average shear bond strength (MPa) for subgroups in both adhesive groups showed a statistically significant difference (p-value ≤0.05). Subgroup A had the highest bond strength (25.786 MPa and 46.943 MPa) and subgroup C had the lowest (8.986 MPa and 9.871 MPa). In both groups, the mean shear bond strength followed this order: Subgroup A > D > E > B > C. Comparison between Group 1 and Group 2 using an independent t-test showed no statistically significant difference in any subgroup (p-value >0.05). Conclusion: The present in-vitro study found that blood and saliva contamination reduced shear bond strength to dentin, with blood having a greater impact. Decontamination with ethanol improved bond strength in both adhesive groups. [ABSTRACT FROM AUTHOR]

This study aimed to evaluate the shear bond strength (SBS) when bonding a universal resin cement to a disilicate glass‐ceramic using different adhesive protocols. Sixty specimens were etched with 10% hydrofluoric acid (HF) for 20 s and assigned to one of four treatment protocols (n = 15): The Positive control protocol comprised use of a universal adhesive system + adhesive resin cement; the Test1 protocol comprised use of a new universal adhesive system + universal resin cement; the Test2 protocol comprised use of a silane coupling agent + universal resin cement; and the use of a universal resin cement without adhesive and silane served as the Negative control. One of the two resin cement cylinders built on each specimen in each group was used to test for 24‐h SBS, while the other was thermocycled and then tested for SBS. Data were submitted to two‐way ANOVA, Tukey's test, and Weibull analysis. The negative control (24 h) showed the lowest SBS mean value. The Test2 protocol resulted in the highest SBS mean value after thermocycling. Adhesive and mixed failures were prevalent in all groups. No statistical difference in m values was observed among the groups at 24 h. After thermocycling, the two Test protocols showed the highest m values. The m values were significantly lower after thermocycling than at 24 h for all groups. After thermal aging, The Test2 protocol resulted in a statistically significantly higher SBS mean value after thermal aging than seen for the other groups. [ABSTRACT FROM AUTHOR]

This study assessed the bond strength of resin‐based restorative materials to fast‐setting calcium silicate cement (Aarhus Uinversity, Denmark) when treated with each of two one‐bottle universal adhesive systems. The cement surface (N = 256) was treated with a self‐priming adhesive and a self‐etch phosphate monomer‐containing adhesive with and without etching of the cement surface. Specimens then received either resin composite or compomer restorative materials (n = 32). The bond strength was measured after 1 day and 1500 thermocycles (n = 16). The failure type was visually inspected. The cement‐adhesive‐restorative material interface was visualized using scanning electron microscopy (SEM). The data were analyzed using multiple linear regression. Restorative material type, resin adhesive system, and thermocycling had a statistically significant effect on the bond strength. Compomer restorative material and self‐etch universal adhesive system demonstrated statistically significantly higher bond strength values to fast‐setting calcium silicate cement, predominantly exhibiting cement cohesive failure. Etching the cement surface enhanced the bond strength of the self‐priming universal adhesive. Thermocycling significantly reduced the bond strength. SEM showed self‐etch universal adhesive seemingly diffused over the etched cement surface compared to other groups. Self‐etch phosphate monomer‐containing universal adhesive and compomer resulted in the highest bond strength to fast‐setting calcium silicate cement. [ABSTRACT FROM AUTHOR]

A promising approach for managing root caries is the use of cross‐linking agents to stabilize collagen. However, despite testing various natural and synthetic agents in vitro, their efficacy remains uncertain. The aim of this review was to examine which cross‐linking agent performs better in reducing root caries lesion depth and the release of hydroxyproline, which is a marker of collagen degradation. Studies evaluating the impact of cross‐linking agents on dentin were included, while studies performed on enamel surface/cell cultures and studies evaluating collagenase inhibitors were excluded, among others. A comprehensive search covered eight databases, and study quality was assessed using the QUINN Tool for in vitro dental studies. Synthesis of the results was done using a Bayesian network meta‐analysis to compare agents. Fifty studies involving 31 cross‐linking agents were included for qualitative synthesis. The network meta‐analysis for lesion depth involved 284 samples across 36 comparisons and ranked cross‐linking agents in terms of their caries lesion depth‐reducing effect (from best to worst): naringin > quercetin > riboflavin > proanthocyanidins > hesperidin > glutaraldehyde > cranberry > grape seed extract > untreated controls. Only naringin, quercetin, proanthocyanidins, and glutaraldehyde showed statistically significant efficacy over untreated controls. Cranberry extract excelled in reducing hydroxyproline release, followed by proanthocyanidins. In conclusion, proanthocyanidins positively affected both outcomes, suggesting they are prime candidates for translational research. Clinical studies are now essential to evaluate their real‐world effectiveness against root caries. PROSPERO‐CRD42023404911. [ABSTRACT FROM AUTHOR]

Introduction: Erbium‐doped yttrium‐aluminum‐garnet (Er:YAG) laser debonding of zirconia and lithium disilicate restorations is increasingly used for a range of clinical applications. Using rotary instruments to remove such restorations for any purpose has proven to be challenging. Erbium laser has been reported to be a conservative method for removing ceramic restorations. There is little data in the literature about the effect of adhesive resin cement type on the debonding time of the ceramic restoration using the Er:YAG laser. Objectives: To evaluate and compare the time required for the Er:YAG laser to debond zirconia and lithium disilicate crowns bonded with a 2‐ and 1‐bottle adhesive resin cement systems. Materials and Methods: Forty extracted premolar teeth were prepared and scanned for milled 40 CAD/CAM crowns. Teeth were randomly assigned into groups (n = 10 per group): 3 mol% yttria‐partially stabilized zirconia crowns 3Y‐PSZ (G1a) bonded with Panavia™ V5 (2‐bottle adhesive resin cement), Zirconia 3Y‐PSZ crowns (G1b) bonded with RelyX™ Ultimate (1‐bottle adhesive resin cement), and for the lithium disilicate crowns bonded with the two types of cements (G2a, G2b). Each specimen was irradiated with an Er:YAG laser at 335 mJ, 15 Hz, 5.0 W, and 50‐ms pulse duration (super short pulse mode). The irradiation time required for crowns to be successfully debonded was recorded for each specimen. Data were statistically analyzed using ANOVA and Tukey HSD post‐hoc test (p < 0.05), at the 95 percent level of confidence. The intaglio surface of the debonded crown was analyzed using scanning electron microscopy (SEM). Results: The mean ± standard deviation times needed for crown debonding were 5.75 ± 2.00 min for the G1a group, 4.79 ± 1.20 min for group G1b, 1.69 ± 0.49 min for group G2a, and 1.12 ± 0.17 for group G2b. There was no statistically significant difference in debonding time between the 2‐ and 1‐ bottle adhesive resin cement within the groups G1a and b (p = 0.2914), or between groups G2a b (p = 0.7116). A statistically significant difference (p < 0.05) was found between groups G1a and G2a and b and between groups G1b and G2a and b were SEM analysis showed no changes in the microstructure of the ceramic surface after Er:YAG laser irradiation. Conclusion: Zirconia and lithium disilicate restorations can be debonded using Er:YAG lasers in a safe and efficient manner. There is no significant difference in the debonding time between the 2‐ and 1‐ bottle adhesive resin cement systems used in this study. Clinical Significance: Retrieving zirconia and lithium disilicate ceramics can be a challenging process when using diamond rotary instruments. ER:YAG lasers may efficiently debond these ceramics from the tooth structure, independent of the bonding process used for bonding them. [ABSTRACT FROM AUTHOR]

To review the published evidence for the role of cross-head speed on the apparent mechanical properties and bond strength of filled resins to tooth structure in order to identify the causes of inconsistency and contradictory results. The data for all available mechanical test results for studies involving dental resins at more than one strain rate was collected from 22 papers. Statistical reanalysis using linear regression was used to test the hypothesis that cross-head speed was correlated with the outcome, with the implication of causality, in each case. In many cases the expected trend was found, in others not. However, it was apparent that the quality of data was often less than can be achieved, and that known interferences have not been recognized. Experimental work for the effect of cross-head speed on bond strength and other properties for dental resin-based materials has often failed to reach the standard which is required for useful data and thus better comprehension of behaviour. Other relevant conditions, such as temperature and water saturation, are in need of attention in this context. [ABSTRACT FROM AUTHOR]

This systematic review evaluated the effect of different hydrofluoric acid (HF) etching regimens and a self-etch ceramic primer (SECP) on the flexural strength (FS) and fatigue failure load (FFL) of glass-ceramic materials.The identification of relevant studies was conducted by two authors in five databases: PubMED, Scopus, Web Of Science, LILACS and Virtual Health Library (BVS) until July 2022 with no year limit. The analysis was conducted in RevMan 5.4.1 Software (Cochrane Collaboration) using Random effect model at 5 %. The risk of bias of the included studies were assessed. From the 5349 articles identified, 34 were included for quantitative analysis. Meta-analysis showed that for predominantly glassy ceramics, etching with HF 5 % had no significant impact on FS, however, HF acid etching with concentrations greater than 5 % negatively impacted FS. For lithium disilicate glass-ceramics (LDGC) HF acid etching, negatively influenced FS, while increasing the FFL. HF etching negatively affected FS of hybrid ceramics. The self-etch ceramic primer and HF acid etching showed a similar impact on FFL and FS. This meta-analysis indicates that the impact of SECP and HF acid etching on the mechanical behavior of glass ceramics is material-dependent. [ABSTRACT FROM AUTHOR]

This study aimed to evaluate the bond strength of adhesively cemented lithium disilicate restorations to dentin by applying different pretreatments and cleaning methods. Twenty-five human posterior teeth were mounted in an acrylic mold, flattened to expose mid-coronal dentin, and divided into five groups based on different pretreatments and cleaning methods prior to adhesive cementation. After cementation, the teeth were sectioned to obtain 1 mm2 specimens, yielding 15 specimens in each group that were subjected to aging and thermocycling process, followed by a microtensile bond test and failure mode assessment. The highest bond strength values were in the control group and in the group that was treated with fluoride and where the temporary cement was removed using pumice, whereas the lowest values were in groups that were cleaned by excavator irrespective of whether they were treated with fluoride or not. However, all groups showed mainly cohesive failure without any statistically significant differences. To eliminate any possible negative impact of eugenol on adhesion to dentin, surface cleaning by rotational brush and pumice is recommended prior to cementing lithium disilicate restorations. [ABSTRACT FROM AUTHOR]

Statement of the Problem: Dentin bonding with etch-and-rinse adhesives involves demineralizing the 5-8µm of the surface dentin to create micro space for resin infiltration. The presence of continuous fluid movement in dentin tubules and positive pulpal pressure prevents complete water replacement by resin monomers. This results in areas of demineralized dentin, which contain collagen fibers without resin infiltration. The exposed collage fibers are subjected to enzymatic degradation leading to less durable hybrid layer. Purpose: The aim of this study was to evaluate the remineralizing effect of the nanoparticles on the resin dentin bonding interface. Materials and Method: The three experimental remineralizing nanoparticles were characterized for their morphology, size, and composition. A total of 48 extracted non-carious human third molar teeth were sectioned at 2 mm below the cemento enamel junction. Class I cavity was prepared and the tooth samples were placed in an intra pulpal pressure simulation device. After etching of the prepared cavity, the samples were randomly divided into four groups (n=10) as follows: (1) control group(c) (n=10) (2) Nano-hydroxyapatite (nHAP) (n=10) (3) Chitosan-nanohydroxyapatite (Chi-nHAP) (n=10) (4) Mesoporous silica-hydroxyapatite (MS-nHAP) (n=10). After 30 days remineralization period, the samples were evaluated for micro tensile bond strength, hybrid layer morphology, and mineral composition of the hybrid layer. The results were analyzed statistically by one-way ANOVA and Tukey's multiple post hoc tests. Results: Scanning electron microscopic observation of nanoparticles revealed irregular particle shapes with calcium phosphate ratio of 1.60. The zeta analyzer showed a mean diameter of 161.0 nm, 323.0nm, 185.0nm for nHAP, Chi-nHAP, and MS-nHAP respectively. Post hoc Bonferroni test revealed significantly higher bond strength for nHAP, Chi-nHAP, and MS-nHAP when compared to control group. MS-nHAP resulted in the uniform deposition of apatite crystal on the surface without any evidence of dentinal tubules openings and had higher mineral to matrix ratio compared to other groups. Conclusion: MS-nHAP nanoparticles can be considered as a reliable source of calcium and phosphate for biomimetic remineralization of hybrid layer. Application of nanoparticle remineralization precursors before application of dentin bonding agents results in remeralization of exposed collagen fibers thereby improving the clinical longevity of hybrid layer. [ABSTRACT FROM AUTHOR]

Statement of the Problem: Dentin adhesion is challenging and needs modifications. Newly introduced nature-derived materials may be a useful solution in improving dentin adhesion. The use of natural antimicrobial agents for pretreating prepared dentin surfaces before restoration has become of interest. Purpose: The present study investigated the effect of natural compounds on the shear bond strength (SBS) of resin composite adhesively bonded to dentin. Materials and Method: Sixty extracted human molar teeth were randomly divided into six groups (n= 10); Group I: two-step etch and rinse adhesive system, Adper Single Bond 2 (SB2) (experimental control), Group II: 2.5% Chitosan+etch+SB2, Group III: 15% Neem (Azadirachta indica)+etch+SB2, Group IV: 15% Tulsi (Ocimum sanctum)+etch+SB2, Group V: 2% Aloe vera+etch+SB2, and group VI: 2% Chlorhexidine (CHX)+etch+SB2. Resin composite (Z350, 3M ESPE USA) was placed over the prepared dentin surfaces and was light cured. Data analysis was performed using One-way ANOVA and post hoc Tukey's test (p< 0.05). Results: Neem specimens showed the highest mean SBS, statistically greater than the control (p= 0.042). Other experimental groups showed no significant differences in SBS comparison to the control. The mean SBS values of 2.5% Chitosan, 15% Neem, 15% Tulsi, and 2% Aloe vera were significantly higher than 2% CHX (p= 0.046, p= 0.001, p= 0.010 and p =0.002 respectively). Conclusion: Dentin pretreatment with Neem may improve the bond strength of a two-step etch and rinse adhesive system. The application of Chitosan, Tulsi, Aloe vera, and CHX did not demonstrate significantly different SBS values from that of the Control, although CHX was lower. [ABSTRACT FROM AUTHOR]

Statement of the Problem: One of the most important factors in the clinical longevity of composite resin restorations is proper adhesion, which is achieved using phosphoric acid. Different phosphoric acid products might affect the micro-shear bond strength of composite resin to enamel. Purpose: The present study aimed to evaluate the micro-shear bond strength of composite resin to sound enamel using six different brands of acid-etch agents. Materials and Method: The present in vitro study was carried out on 72 extracted sound human (mandibular and maxillary) first premolar teeth. The teeth crowns were divided into two equal parts with a mesiodistal cut and randomly assigned to six groups in terms of the acid etchant brand: Ultra-etch, SDI, Morvabon, FGM, Nik Darman, and Experimental. The bonding procedure was carried out using the Margin Bond enamel adhesive. Tygon tubes (1×0.7 mm) containing composite resin were bonded to each enamel surface. After 24 hours of storage in distilled water, each sample underwent a shearing force with a crosshead speed of 0.5 mm/min. The morphologic changes were evaluated using scanning electron microscopy. The data were analyzed with SPSS using one-way ANOVA and Tukey test (p< 0.05). Results: One-way ANOVA showed that micro-shear bond strength in different etchant agents have significant differences (p< 0.001). The highest and lowest composite resin micro-shear bond strengths belonged to Ultradent and SDI brands, respectively. The enamel surfaces in the SDI group revealed residual debris after dissolution. Conclusion: Preparation of the enamel surface with different phosphoric acid products might affect the micro-shear bond strength and enamel surface morphology differently. Further clinical studies are suggested to evaluate the effect of different types and concentrations of acid etching agents on the enamel and dentin bonds. [ABSTRACT FROM AUTHOR]

Objectives: This study was designed to assess the effectiveness of chitosan as a coupling agent for improving the tensile bond strength of fiber posts. Methods: A total of 91 single-rooted mandibular teeth were root canal-filled. Post spaces were created and categorized into seven groups: Group A (Control), Group B (Silane), Group C (Chitosan), Group D (37% Phosphoric acid + Silane), Group E (37% Phosphoric acid + Chitosan), Group F (10% Hydrogen Peroxide + Silane), and Group G (10% Hydrogen Peroxide + Chitosan). Posts were cemented and tensile bond strength was measured, while the morphological structure of the fiber posts was analyzed using Scanning Electron Microscopy. One-way (ANOVA) and Tukey's multiple comparison tests were performed at a level of significance of 5%. The percentages of fracture patterns among the groups were compared. Results: 10% Hydrogen peroxide + Chitosan exhibited the significantly highest tensile bond strength (p < 0.001). Adhesive failures were more frequent in Groups A, B, C, and D, whereas cohesive failures within the resin cement were predominant in Groups E, F, and G. Conclusions: The protocol of using 10% hydrogen peroxide followed by a chitosan coupling agent significantly improved tensile bond strengths for glass fiber posts, which highlights the potential of using chitosan as a natural biopolymer and an alternative to synthetic coupling agents to develop more effective bonding strategies for dental restorations. [ABSTRACT FROM AUTHOR]

Statement of the Problem: One of the most important factors in the clinical longevity of composite resin restorations is proper adhesion, which is achieved using phosphoric acid. Different phosphoric acid products might affect the micro-shear bond strength of composite resin to enamel.Purpose: The present study aimed to evaluate the micro-shear bond strength of composite resin to sound enamel using six different brands of acid-etch agents.Materials and Method: The present in vitro study was carried out on 72 extracted sound human (mandibular and maxillary) first premolar teeth. The teeth crowns were divided into two equal parts with a mesiodistal cut and randomly assigned to six groups in terms of the acid etchant brand: Ultra-etch, SDI, Morvabon, FGM, Nik Darman, and Experimental. The bonding procedure was carried out using the Margin Bond enamel adhesive. Tygon tubes (1×0.7 mm) containing composite resin were bonded to each enamel surface. After 24 hours of storage in distilled water, each sample underwent a shearing force with a crosshead speed of 0.5 mm/min. The morphologic changes were evaluated using scanning electron microscopy. The data were analyzed with SPSS using one-way ANOVA and Tukey test (p< 0.05).Results: One-way ANOVA showed that micro-shear bond strength in different etchant agents have significant differences (p< 0.001). The highest and lowest composite resin micro-shear bond strengths belonged to Ultradent and SDI brands, respectively. The enamel surfaces in the SDI group revealed residual debris after dissolution.Conclusion: Preparation of the enamel surface with different phosphoric acid products might affect the micro-shear bond strength and enamel surface morphology differently. Further clinical studies are suggested to evaluate the effect of different types and concentrations of acid etching agents on the enamel and dentin bonds.

Aim: This study aimed to evaluate the bond strength of adhesively cemented lithium disilicate restorations to dentin by applying different pretreatments and cleaning methods. Material and Methods: Twenty-five human posterior teeth were mounted in an acrylic mold, flattened to expose mid-coronal dentin, and divided into five groups based on different pretreatments and cleaning methods prior to adhesive cementation. After cementation, the teeth were sectioned to obtain 1 mm2 specimens, yielding 15 specimens in each group that were subjected to aging and thermocycling process, followed by a microtensile bond test and failure mode assessment. Results: The highest bond strength values were in the control group and in the group that was treated with fluoride and where the temporary cement was removed using pumice, whereas the lowest values were in groups that were cleaned by excavator irrespective of whether they were treated with fluoride or not. However, all groups showed mainly cohesive failure without any statistically significant differences. Conclusions: To eliminate any possible negative impact of eugenol on adhesion to dentin, surface cleaning by rotational brush and pumice is recommended prior to cementing lithium disilicate restorations.

This systematic review evaluated the effect of different hydrofluoric acid (HF) etching regimens and a self-etch ceramic primer (SECP) on the flexural strength (FS) and fatigue failure load (FFL) of glass-ceramic materials.The identification of relevant studies was conducted by two authors in five databases: PubMED, Scopus, Web Of Science, LILACS and Virtual Health Library (BVS) until July 2022 with no year limit. The analysis was conducted in RevMan 5.4.1 Software (Cochrane Collaboration) using Random effect model at 5 %. The risk of bias of the included studies were assessed. From the 5349 articles identified, 34 were included for quantitative analysis. Meta-analysis showed that for predominantly glassy ceramics, etching with HF 5 % had no significant impact on FS, however, HF acid etching with concentrations greater than 5 % negatively impacted FS. For lithium disilicate glass-ceramics (LDGC) HF acid etching, negatively influenced FS, while increasing the FFL. HF etching negatively affected FS of hybrid ceramics. The self-etch ceramic primer and HF acid etching showed a similar impact on FFL and FS. This meta-analysis indicates that the impact of SECP and HF acid etching on the mechanical behavior of glass ceramics is material-dependent.

This study investigated the effect of erbium, chromium: yttrium-scandium-gallium-garnet (Er,Cr:YSGG) laser conditioning on dentin bond strength and nanoleakage of different universal and self-etch adhesives. A total of 84 intact human third molar teeth were cut at the dentin level, and half of them were laser conditioned. The specimens were divided into three groups; two different universal resins and one self-etch adhesive resin were applied and composite resin restorations were created. For the microtensile bond strength (pTBS) test, 20 microspecimens were prepared from the laser and control group of each adhesive (n = 20) and tested with a universal device. For nanoleakage observation, 10 specimens were prepared from each group (n = 10) and stored in silver nitrate solution, and then the amount of nanoleakage was analyzed by field emission scanning electron microscopy (FESEM). Data were analyzed with two-way ANOVA, Tukey's honestly significant difference, and chi-square tests. The mean dentin bond strength of all adhesives in the laser groups was found to be statistically significantly lower than those of the control groups (P < .05). No difference was found between the mean bond strength of the adhesives in the laser and control groups (P > .05). Higher nanoleakage was observed in all adhesives in the laser groups compared to the control groups (P < .05). Irradiation of the dentin surface with Er,Cr:YSGG could adversely affect the piTBS and nanoleakage, likely by affecting the structure of the hybrid layer. [ABSTRACT FROM AUTHOR]

Purpose: To evaluate the marginal leakage of three different types of bonding agents used with two posterior composites and a giomer, available commercially. Material and methods: Class II box-only cavities were prepared on 90 mandibular first molars with margins extending 1 mm beyond the cementoenamel junction. The samples were divided into nine groups based on three different bonding agents, two different composites, and a giomer. Cavities were restored per the manufacturer's description. Teeth were subjected to a thermocycling procedure (500Ã--, 5°C to 55°C) and dye penetration by immersing in a 2% methylene blue solution (Merck Specialties) for 24 hours. The marginal adaptation was evaluated as a continuous margin at the gingival level under a stereomicroscope. The results were analyzed using the Kruskal-Wallis and Mann-Whitney U tests. Results: The results of the groups with the total-etch technique showed no statistical difference between the nanohybrid Filtek Z250 XT (3M ESPE) and fine hybrid SwissTEC composite (Coltène\Whaledent AG). The groups with the self-etch technique showed no statistical difference when used with either of the two composites. The acid-etch technique showed better marginal adaptation than the self-etch technique. When the giomer (Beautifil II, Shofu) was used with the total-etch technique, it showed better adaptation than when used with the self-etch technique but overall showed more marginal leakage than the composites. Conclusion: The total-etch technique provided better marginal adaptation for the composites and giomer compared to the self-etch technique. Clinical significance: The demand for esthetic restorations continues to increase, and composite restorations are now considered the material of choice for Class II cavities. There are various concerns with composite restorations, one of them being good marginal adaptation to increase the life of the restoration. This study evaluated marginal leakage with the nanohybrid composite Filtek Z250 XT, fine hybrid composite SwissTEC, and a giomer when used with the total-etch technique and self-etch technique and reported satisfactory adaptation with the total-etch technique. [ABSTRACT FROM AUTHOR]

The purpose of this study was to evaluate the effect of 2% chlorhexidine (CHX) on an etch-and rinse adhesive to dentin. Caries-free molars were selected and processed to expose a flat dentin surface. The specimens were bonded with a composite resin by an etch-and-rinse adhesive, which was pretreated with 2% CHX for 0, 15, 30, 45, and 60 seconds. The microtensile bond strength (MTBS) was evaluated before and after thermocycling. No significant differences were observed between groups before thermocycling. The 60-second CHX-pretreated group showed a significantly greater MTBS than the control group after thermocycling. The 2% CHX pretreatment could improve the bonding strength of the etch-and-rinse adhesive and slow down the aging progress of the bonding interface. [ABSTRACT FROM AUTHOR]

This article investigated the effects of airborne-particle abrasion and nanosilica (nano-Si) infiltration treatment on the surface characteristics of dental zirconia. A total of 15 unsintered zirconia ceramic green bodies (10 x 10 x 3 mm) were divided into three groups (n = 5): Group C, no treatment after sintering; Group S, airborne-particle abrasion with 50-p.m aluminum oxide particles after sintering; and Group N, infiltration of nano-Si followed by sintering and hydrofluoric acid (HF) etching. The zirconia disks' surface roughness was analyzed by atomic force microscopy (AFM). The surface morphology of the specimens was analyzed using scanning electron microscopy (SEM), and the chemical composition was analyzed by energy-dispersive x-ray (EDX). Data were statistically analyzed by the Kruskal-Wallis test (P < .05). Zirconia surface treatments by infiltration of nano-Si, sintering, and HF etching showed multiple changes in the surface features. The surface roughness of Groups C, S, and N were 0.88 ± 0.07 µm, 1.26 ± 0.10 µm, and 1.69 ± 0.15 µm, respectively. The surface roughness of Group N was significantly higher than that of Groups C and S (P < .05). EDX analysis showed peaks that corresponded to silica (Si) after infiltration with colloidal Si that disappeared following acid etching. Infiltrating nano-Si increases the surface roughness of zirconia. The formation of retentive nanopores on the surface potentially improves the zirconia-resin cement bonding strengths. [ABSTRACT FROM AUTHOR]

Two fractured maxillary central incisors were restored via the crown fragment reattachment technique with adhesive systems and composite resin material. A long-term successful outcome was achieved after 4 years of follow-up. The patient presented with fractured maxillary central incisors, and a comprehensive intraoral and radiographic examination revealed that both teeth had extended crown fractures with no pulpal exposure (Class II, Ellis and Davey). The tooth fragments were thoroughly cleaned and inspected before being repositioned. Both fragments were in excellent condition with almost no pieces missing. Therefore, the proposed treatment was fragment reattachment. After verifying the repositioning and adaptation of the fractured fragments, a flowable composite was used to perform the reattachment procedure under rubber dam isolation. With modern dental adhesives, the reattachment of tooth fragments in good condition is considered a more conservative option for restoring tooth morphology, esthetics, and function. Although one tooth showed signs of irreversible pulpitis and required root canal treatment 2 weeks after the restoration, the clinical and radiographic evaluations at the 4-year follow-up visits confirmed the success of the restorative treatment. The restorations showed good functional and esthetic outcomes after 4 years of follow-up. [ABSTRACT FROM AUTHOR]

Abstract In this multi-parameter study, the effect of diverse factors related to adhesive application on the activation of host-derived gelatinases was investigated by gelatin zymography, in-situ zymography, fluorogenic DQ-gelatin assay and micro-tensile bond-strength (μTBS) testing. Gelatin zymography disclosed the presence of gelatinases in phosphoric acid-etched dentin powder, while two gold-standard adhesives generated no measurable MMP activation. In-situ zymography revealed that the interfacial gelatinolytic activity from specimens treated with the two adhesives appeared similar as that of the EDTA negative control, indicating no detectable gelatinases were activated upon adhesive treatment. In solution, MMP-2/9 activity significantly decreased upon interaction with both adhesives (two-way linear mixed effects model [LMEM]: p 0.05). Taken together, the two adhesives did not activate but rather inhibited the release and activation of dentinal gelatinases.

Objective: This systematic review evaluated how different storage times and conditions affect universal adhesives' bond strength and degree of conversion (DC).Methods: A literature search was conducted in PubMed, Scopus, Web of Science, and Google Scholar databases for articles published from January 1st, 2000, until May 15th, 2022. The researchers comprehensively evaluated the articles using a multi-step process to identify articles relevant to the topic of interest. Quality assessment was performed through the ROBDEMAT tool. Due to the high heterogeneity in the preliminary data, performing a meta-analysis was not feasible.Results: A total of 3169 records were obtained, and after removing duplicates, 2267 remained. Following title and abstract screening, 2253 studies were excluded based on the predetermined exclusion criteria. Of the 14 remaining studies, seven were further excluded due to the use of non-universal adhesives, experimental adhesives, or lack of aging protocols. Ultimately, seven studies were included in this systematic review. All studies focused on bond strength, with only one addressing DC. The Findings showed that aging or different storage conditions generally led to reduced bond strength and DC values in universal adhesives, although exceptions with stable or improved properties were noted.Conclusions: Adhesives with higher pH and those containing methacrylamides, HEMA-free compositions, or hydrolytically stable monomers showed better durability than others. Strict adherence to storage instructions, lower storage temperatures, and immediate recapping of adhesive bottles after use is recommended to maintain adhesive properties. These findings provide insights for optimizing the long-term performance of universal adhesives in clinical settings.