Scotchbond Multi-Purpose Research Articles

Impact of functional monomers, bioactive particles, and HEMA, on the adhesive performance of self-etch adhesive systems applied to simulated altered dentin

ObjectivesThis study aimed to evaluate how self-etching/universal dental adhesive systems (DASs) with differing compositions interact with sound (S), post-radiotherapy (irradiated; I), and artificially eroded (E) dentin in terms of bonding properties. Methods: The DASs tested were Adper Scotchbond Multipurpose (MP; control), Clearfil SE Bond (SE), FL Bond II (FL), Adper Single Bond Universal (SU) and BeautiBond Xtreme (BX). They were analyzed for initial and 6-month microtensile bond strength (µTBS, n = 12), mode of failure (40 x), scanning electron microscopy (SEM), surface wettability (W, n = 10), and degree of conversion (DC, n = 3) via Fourier-transform infrared spectroscopy (FTIR). Normal and homogeneous distribution of the data allowed their analyses through ANOVA and Tukey tests (p < 0.05). Results: All DASs except BX exhibited higher µTBS for S decreasing for I and E. BX demonstrated the greatest stability among the altered substrates. FL showed the most hydrophobic properties, likely due to its bioactive components. Universal DASs achieved higher DC, regardless of composition. Conclusions: HEMA-free formulation combined with carboxylic and phosphoric acids in BX, achieved the most stable performance for altered substrates. Clinical SignificanceSince radiotherapy and erosion affect dentin, their characteristics compromise adhesive performance and impair the achievement of durable and satisfactory restorations. The use of universal adhesives less dependent on calcium seems less susceptible to hydrolytic degradation and may be a promising option for maintaining adhesive stability over time.

Marginal integrity of prototype bioactive glass-doped resin composites in class II cavities.

This in vitro study examined the marginal integrity of experimental composite materials doped with bioactive glass (BG). Class-II MOD cavities were prepared and restored with one of the following composite materials: a commercial composite material as a reference (Filtek Supreme XTE), an experimental composite doped with BG 45S5 (C-20), and an experimental composite doped with a fluoride-containing BG (F-20). Six experimental groups (n = 8) were used, as each of the three composites was applied with (+) or without (-) a universal adhesive (Adper Scotchbond Multipurpose). All specimens were subjected to thermocycling (10,000 x, 5-55°C) and then additionally stored in artificial saliva for eight weeks. Scanning electron micrographs of the mesial and the distal box were taken at three time points (initial, after thermocycling, and after eight weeks of storage in artificial saliva). The margins were classified as "continuous" and "non-continuous" and the percentage of continuous margins (PCM) was statistically analyzed (α = 0.05). In most experimental groups, thermocycling led to a significant decrease in PCM, while the additional 8-week aging had no significant effect. F-20 + performed significantly better (p = 0.005) after 8 weeks storage in artificial saliva than the reference material with adhesive, while no statistically significant differences were observed at the other two time points. C-20 + exhibited significantly better PCM than the reference material with adhesive after thermocycling (p = 0.026) and after 8 weeks (p = 0.003). Overall, the experimental composites with BG showed at least as good marginal adaptation as the commercial reference, with an indication of possible re-sealing of marginal gaps. Maintaining or improving the marginal integrity of composite restorations is important to prevent microleakage and its likely consequences such as pulp irritation and secondary caries.

Clinical evaluation of Giomer and self-etch adhesive compared with nanofilled resin composite and etch-and-rinse adhesive – Results at 8 years

ObjectiveThis study aimed to evaluate the long-term clinical performance of Giomer and a self-etch adhesive system compared with a nanofilled resin composite and etch-and-rinse adhesive system in Class I and Class II restorations. MethodThe study was designed to be double-blinded with intra-individual control. 48 patients with 54 pairs of cavities (class I or class II) were recruited. Each pair of restorations was placed with either BEAUTIFIL II (BF) and FL-BOND II (FL) or Filtek Z350 (Z350) and Scotchbond Multi-Purpose (SMP). Clinical evaluation was performed at baseline, 6-month, 18-month, 4-year and 8-year after placement according to modified USPHS criteria. Kaplan-Meier survival analysis and log rank tests were performed (SPSS 20.0, IBM Corporation, US) to compare the survival probability of different restorations.A generalized linear mixed model (GLMM) was adopted to assess the performance of the materials. The McNemar test was used to show significant changes for all the evaluation criteria and difference between them. ResultsAt the eight-year recall, 32 patients with 67 restorations were present. There were twelve restorations in total recorded as failure due to loss of retention, restoration fracture, secondary caries, tooth fracture or endodontic treatment due to pulp necrosis. The survival probabilities and calculated annual failure rate(AFR) of BF and Z350 restorations at 8-year were 87.2 % vs 87.8 % and 1.6 % vs 1.5 % respectively with no significant difference (p > 0.05)between the two materials. Over the recall time range of eight years, decreased possibility of alpha rating was observed for retention, marginal adaptation, marginal staining and surface roughness for both materials (p < 0.05). Decreased possibility of alpha rating was observed for surface staining and secondary caries for Z350 (p < 0.05) and restoration fracture for BF (p < 0.05), respectively. Comparing the two restorative systems over eight years, no significant difference was seen for linear decline of the possibility of alpha rating for any of the criteria evaluated (p > 0.05). ConclusionGiomer material and the self-etch adhesive system had comparable clinical performance with nanofilled resin composite and etch-and-rinse adhesive system over the observation period of eight years.

Sealing of pulp chamber dentin in endodontics: Influence of bond strategy and time-point application

Context: Seal the dentin of the pulp chamber during endodontic treatment to avoid interfering with the restorative treatment performed afterward. Aims: The aim was to evaluate the effect of three adhesive systems applied in different bonding strategies (etch-and-rinse, self-etch, and universal adhesive) and time-point application (immediately after the cavity access preparation or after endodontic obturation) on the hybrid layer formation and dentinal penetrability. Materials and Methods: Forty-eight sound molars were randomly distributed into six groups (n = 10) according to the adhesive system used: Forty-eight sound molars were randomly distributed into six groups (n = 10) according to the adhesive system used and the time-point application: Adper Scotchbond Multi-purpose (AS), Clearfil SE (CF) and Scotchbond Universal (SU) in strategy of immediate endodontic sealing (IES) or delayed endodontic sealing (DES). In IES-AS, IES-CF, and IES-SU groups, dentin sealing was performed immediately after the cavity access, while in DES-AS, DES-CF, and DES-SU, after root canal obturation. The specimens were sectioned in the long axis, in a buccal-lingual direction, and the dentinal penetrability of the adhesive systems was evaluated using confocal microscopy images. Hybrid layer formation was analyzed by scanning electron microscopy images. Statistical Analysis Used: Dentinal penetrability data were analyzed with the ANOVA test and the Kruskal–Wallis test was performed for hybrid layer data (α = 0.05). Results: IES-CF showed the lowest dentinal penetrability (P &lt; 0.05), while the other protocols were similar to each other (P &gt; 0.05). No significant differences were found between groups regarding the hybrid layer formation (P &gt; 0.05). Immediate and DES protocols do not influence the hybrid layer formation, regardless of the bond strategy used. Conclusions: Sealing the pulp chamber dentin before endodontic treatment can improve the bond strength of the final restoration but the formation of the hybrid layer was not influenced by the bond strategy.

Universal Adhesive Application Modes Differentially Affect the Fracture Resistance of Resin Composite Restored Teeth.

This study evaluated the fracture resistance of teeth with mesio-occluso-distal (MOD) resin composite restorations using universal adhesive (Single Bond Universal; SBU) in three different manipulation modes compared with those using two-step self-etch (Clearfil SE bond; CSE) and 3-step etch-and-rinse (Scotchbond Multi-Purpose; SBMP) adhesives at 24 hours and after thermocycling. One hundred and sixty maxillary premolars were assigned into eight groups of 20 each. Intact teeth and nonrestored cavity-prepared teeth served as controls. For the remaining specimens, cavities were restored with resin composite using different adhesives-SBU in self-etch, etch-and-rinse, or selective enamel etching modes; CSE in self-etch or selective enamel etching; and SBMP. Specimens from each group were either stored in 37°C water for 24 hours or further submitted to thermocycling for 30,000 cycles (n=10), then subjected to axial compression stress until fracture. Fracture patterns were observed microscopically. Data were statistically analyzed at a 95% confidence level. Among the restored teeth, mean failure load of the group using SBMP was the highest at both short-term and long-term evaluation periods (p<0.05). Fracture strengths of the SBU groups where enamel was etched with phosphoric acid prior to the adhesive application were similar and were greater than in those specimens without pre-etching (p<0.05). After thermal aging, a significant decrease in fracture resistance value was detected only for the group using SBU in etch-and-rinse application mode (p<0.05). For the self-etch strategy, SBU demonstrated lower load to fracture than CSE following thermocycling; all specimens failed at and beneath the crestal level (p<0.05). Application of SBU universal adhesive in selective enamel etching mode provided higher and more stable fracture resistance of teeth with MOD resin composite restorations than in self-etch mode.

Saliva with different concentrations of enzyme with esterolytic activity, and its effect on the immediate and long-term bond strength of adhesive systems to dentin

The present study evaluated whether different concentrations of albumin would influence the immediate or long-term bond strength of adhesive systems to dentin. Human third molars (N = 90) were sectioned at the dentin-enamel junction to obtain middle dentin occlusal surfaces. After sectioning into discs, the molars were restored with resin composite (Filtek Z250, 3 M/ESPE) by using an etch-and-rinse (Adper Scotchbond Multi-Purpose, 3 M/ESPE) or a self-etch (Clearfil SE Bond, Kuraray) adhesive system. The specimens were then sectioned into beams and stored in artificial saliva containing albumin in regular (100 μg/mL; SA100) or elevated (700 μg/mL; SA700) concentration—both concentrations simulated the range in which this enzyme may be present clinically, depending on the patient's periodontal condition. Beams from the control group (CO) were kept in artificial saliva with no addition of albumin. Half of the beams from each group were stored for 24 h, and the remainder, for 12 months. Then, the microtensile bond strength test was performed, and the failure mode was analyzed (adhesive, cohesive, or mixed). Bond strength data were submitted to the generalized linear model, followed by the Tukey tests, and failure modes were compared using chi-square tests (α = 5%). There were no significant interactions, but there was a significant effect between the albumin concentration (p = 0.015) and the time factor (p = 0.016). The beams stored in SA700 had significantly lower bond strength in comparison with the CO beams, regardless of the adhesive system. At 12 months, the bond strength decreased significantly for all groups. SA700 caused a significant increase in the adhesive failures after 12 months (p = 0.005). It was concluded that the bond strength of both adhesive systems was impaired by the albumin concentration aging.

Bond Strength of Two Resin Cements with Leucite-reinforced Ceramic Using Different Bonding Agents.

To compare the bond strength of two resin cements to leucite-reinforced ceramics using three different boding agents and evaluate the compatibility of bonding agents. Twenty extracted sound human molars were sectioned horizontally 2-3 mm above the cementoenamel junction (CEJ). CAD/CAM ceramic blocks for inLab were also sectioned to create 4 mm thick and bonded to the dentin. The adhesive groups assigned were divided into four adhesive groups: Group I: Variolink II dual-cure resin cement and Scotchbond Multi-Purpose Plus adhesive, group II: Multilink Automix dual-cure resin cement and Multilink primers, group III: Multilink Automix and Clearfil SE bond 2 (CSE2) adhesive, group IV: Multilink Automix and CSE2 with light curing after adhesive application. Five specimens of each group were sectioned perpendicular to obtain six microsticks of 1 × 1 mm width from each sample. Microtensile bond strength data were expressed in MPa. Fracture modes (FrMs) analyzed for the surfaces were divided into six patterns. Microtensile bond strength data were statistically analyzed with one-way ANOVA and Tukey post hoc tests (α = 0.05). T-test was performed at the 5% significance level to analyze groups III and IV with and without light curing. Group I showed the highest μTBS average of 13.67 MPa, group IV showed 12.26 MPa, group III showed 12.15 MPa, and group II showed the lowest average of 10.84 MPa. No significant differences were found between the bonding agents. However, the six types of failure modes, although all observed, were characterized by the adhesive system: Type I: adhesive failure of laminated dentin and ceramic; type II: adhesive failure of laminated ceramic; type III: adhesive failure of laminated dentin; type IV: cohesive failure of luting agent; type V: cohesive failure of dentin, and type VI: mixed failure of adhesion and cohesion. As a result, the FrM most commonly observed was the adhesive failure at the luting cement-ceramic block interface. The combination of resin cements and bonding agents did not significantly affect the bond strength of CAD/CAM ceramic restorations and dentin. Several universal bonding agents are currently available for direct and indirect bonding, and using the same bonding agent for direct and indirect restorations could simplify inventory and benefit routine clinical practice. How to cite this article: Aida N, Koi K, Amaya-Pajares SP, et al. Bond Strength of Two Resin Cements with Leucite-reinforced Ceramic Using Different Bonding Agents. J Contemp Dent Pract 2023;24(11):859-863.

Novel resin-based material containing β-tricalcium phosphate nanoparticles for the reduction of dentin permeability

ObjectivesTo synthesize and characterize a novel dentin adhesive containing Beta-Tricalcium Phosphate (β-TCP) nanoparticles and test its ability to reduce dentin permeability (dP). MethodsExperimental adhesives were prepared by mixing Bis-GMA, TEGDMA, HEMA (50/25/25 wt.%), photo-initiators, and inhibitors. The following groups were tested: Experimental adhesives without β-TCP (Exp.); with 10 wt.% β-TCP (Exp.10 wt.% β-TCP); with 15 wt.% β-TCP (Exp.15 wt.% β-TCP), Scotchbond Multi-Purpose (SBMP) and Clearfil SE Protect Bond (CFPB). Degree of conversion (DC%, 10 and 20 s); Flexural Strength (FS), Knoop Hardness (KHN), and Cell Viability (OD%) tests were performed. dP was evaluated by hydraulic conductance, using human dentin disks (n=12), at three-time intervals: post-EDTA (T0); post-treatment (T1); and post-erosion/abrasion cycling (T2). Data were statistically analyzed (α=0.05). ResultsFor all groups, exposure time for 20 s presented a higher DC% than for 10 s. For FS, filled adhesives did not differ from unfilled and from CFPB. Experimental adhesives did not differ among them and showed lower KHN than the commercial products. Cell viability did not differ among adhesives, except Exp. 15 wt.%, which showed lower OD% than Exp., Exp. 10% and, CFPB. For dP, only Exp.10 and 15 wt.% β-TCP did not present difference between the times T1 and T2. After cycling, Exp.10 wt.% β-TCP presented lower permeability than Exp. and CFPB. ConclusionsThe incorporation of 10 wt.% β-TCP nanoparticles into the resin-based dental material did not affect its mechanical properties and biocompatibility, and promoted the greatest reduction in dentin permeability, sustaining this effect under erosive/abrasive challenges. Clinical significanceA novel resin-based dental material containing β-TCP nanoparticles was able to reduce dentin permeability, maintaining its efficacy after erosive/abrasive challenges. The synthesized material did not affect dental pulp cell viability and might be promising for other conditions that require dental remineralization, such as tooth wear and dental caries.

Bonding stability of universal adhesives to feldspathic ceramic with or without prior silane application.

This study aimed to assess the bonding stability of three universal adhesives to a CAD-CAM feldspathic ceramic with or without prior silane application. The universal adhesives tested were Ambar Universal (FGM), Single Bond Universal (3M), and Ybond Universal (Yller). Scotchbond Multipurpose Plus (3M) was used as a control. The silane used was RelyX Ceramic Primer (3M). Microtensile bond strength (μTBS) to Vitablocs Mark II was measured after 24 h or 6 months of water aging (n = 20). Failure modes were observed through scanning electron microscopy, and pH and degree of C = C conversion (DC) of the adhesives were measured (n = 3). Data were analyzed using One-, Two-, and Three-Way ANOVA. The pH values differed significantly among the adhesives (P<0.001), while the DC was similar (P = 0.141). The universal adhesives showed significant differences in μTBS, with higher immediate results when using silane and lower results after aging. Notably, a significant decrease in μTBS was observed after 6 months when silane was applied. In contrast, the control adhesive exhibited consistent results between the 24-hour and 6-month storage periods. The universal adhesives showed a decrease in μTBS ranging from 25.5% to 40.1% after prolonged storage. Adhesive failures were predominant in all groups. The presence or absence of silane in the adhesive composition did not affect the bonding performance. The application of a separate silane coupling agent improved the immediate bond strength of universal adhesives to CAD-CAM feldspathic ceramic. However, this bond strength significantly decreased after 6 months of water aging. The bond strength remained stable for universal adhesives when applied without silane after 6 months of aging. This article is protected by copyright. All rights reserved.

Effect of Nano-sized Hydroxyapatite Filler on Remineralization Efficacy of an Adhesive Resin: an in vitro study

Aim The aim of this study was to evaluate the remineralization efficacy of an adhesive resin containing nano-sized hydroxyapatite filler. Methodology The study consisted of four groups: control (without filler), 2% hydroxyapatite (HA), 5% HA, and 7% HA. Nano-hydroxyapatite powder was mixed with Scotchbond Multi-Purpose®. The teeth were sectioned to expose the midcoronal dentine. Bonding agents and resin composite restorations were applied. Teeth were incubated in simulated body fluid for 24-h, 30-day, and 90-day intervals. After incubation, the teeth were sliced. Hardness and elasticity modules were obtained for the three different time periods (for a total of n = 360 samples). The detection and measurement of mineral deposition areas were obtained by confocal laser scanning microscopy (CLSM) (for 120 samples). Elemental analysis was performed with energy-dispersive X-ray spectroscopy (EDS) (n = 360 samples). The statistical analysis of each parameter was performed using two-way ANOVA and group comparisons by post hoc tests. Results Study groups and storage periods affected the hardness (p = 0.00) and elasticity scores (p = 0.00). The CLSM results showed that increasing the storage periods and amount of HA resulted in mineral deposition areas (p = 0.02). The calcium and phosphor ion values of dentine that were obtained using EDS were increased (p = 0.00). Conclusion Hydroxyapatite fillers positively affect the remineralization activity of adhesive resins. In terms of remineralization efficacy, the best results were obtained in the 7% HA group.

The Effect of Ground and Unground Enamel on the Clinical Performance of Direct Composite Build-up After Orthodontic Treatment: Five Years of Follow-up.

To assess the clinical performance of restorations with ground and unground enamel for diastema closure. Twenty-four patients attended and received two to ten composite build-ups for diastema closure. The restorations were performed separately by grinding and not grinding the enamel on the proximal surfaces on symmetric teeth. A nanofill direct composite (Filtek Ultimate Universal Restorative System, 3M ESPE, St Paul, MN, USA) was used with a three-step etch-and-rinse adhesive (Scotchbond Multi-Purpose, 3M ESPE) for restorations. Restorations were evaluated according to the modified United States Public Health Service (USPHS) criteria at baseline and 1-, 2-, 3-, 4-, and 5-year recalls. The cumulative success rate of direct composite build-up with ground and unground enamel was 100% and 88.7%, respectively. Six restorations with unground enamel failed due to fracture. No significant difference was found between the restorations with ground enamel and unground enamel with regard to the evaluation criteria. The 5-year success rates of restorations with ground and unground enamel were excellent. The success rate of restorations with ground enamel was higher than that of restorations with unground enamel. Fracture was the reason for failure in the restorations with unground enamel.

Effect of Internal Bleaching on the Microshear Bond Strength of Composite Resin to Dentin in Recently Restored Teeth

Background: This study aimed to assess the effect of internal bleaching on the microshear bond strength of composite resin to dentin in recently restored teeth.&#x0D; Methods: This in vitro, experimental study evaluated 40 sound human premolars. The teeth were sectioned below their cementoenamel junction. Access cavity was prepared, pulpal tissue was removed and filled with glass ionomer. The teeth were then randomly divided into 4 groups. In the control group, no internal bleaching was performed and dentin surface was restored with composite. In group 2, internal bleaching with 35% hydrogen peroxide (Opalescence, ultradent) was performed 4 weeks after composite restoration. Bleaching was performed immediately after restoration of teeth in groups 3 and 4. Teeth were etched with 35% phosphoric acid for 15 seconds, rinsed, dried, and primer and adhesive (Adper Scotchbond Multipurpose) were applied. The teeth were then restored with Z250 (3M ESPE) microhybrid resin composite. Teeth were sectioned into 1 mm2 sections and underwent micro-shear bond strength test. In groups 1 to 3, bond strength was measured after 24 hours while in group 4, it was measured after 1 month. Data were analyzed using one-way ANOVA.&#x0D; Results: The mean micro-shear bond strength of composite to dentin was maximum in group 2 and minimum in group 3. However, the difference in this respect was not significant among the groups (p&gt;0.05).&#x0D; Conclusion: In teeth requiring immediate esthetic restorations, treatments can be performed after non-vital bleaching with no time restriction and adequately high bond strength comparable to non-bleached teeth.

Effect of full-step versus simplified resin cement luting strategies on the push-out bond strength of indirect resin composite restorations bonded to dentin

Indirect restorations made of resin composite materials are increasingly used yet there is no consensus in the literature on how different luting strategies influence the bond strength. The aim of this was to study the influence of luting strategy and aging on the adhesion of indirect restorations on dentin. Bovine incisors (N = 120) received conical cavities and filled them with resin composite. The cone sets were divided into 8 groups (n = 15 each) and the cylinders were cemented according to: ‘Luting strategy’ (U200: Self-adhesive cement resin; ULT: Scotchbond Universal + RelyX Ultimate; SB2: Phosphoric Acid + Adper Single Bond 2 + RelyX ARC; SBMP: Phosphoric Acid + Scotchbond Multi-purpose + ARC) and ‘Aging’ (Tc: With thermocycling/10.000 cycles: 5–55 °C; Without thermocycling). The specimens were subjected to a Push-out Bond Strength (σ) (100 kgf; 0.5 mm/min). Stereomicroscope and scanning electron microscopy (SEM) images were made to classify the failures. Data (MPa) were submitted to two-way-ANOVA, Tukey (α = 5%), and Weibull tests. ANOVA revealed that ‘luting strategy’ and ‘aging’ were statistically significant. When the factor ‘TC’ was evaluated separately, the TC groups presented higher bond strength than the unaged groups. As for the non-thermocycling groups, the different luting strategies had no statistical difference, except for the SB2 group, which was lower than ULT. Among all groups, TC, U200_Tc, SBMP_Tc, and ULT_Tc were statistically similar and significantly higher than that of the SB2-Tc group. The Weibull modulus was statistically different among the groups but characteristic strength was significant. Mixed failures were predominantly observed. Self-conditioning strategy promoted higher bond strength than the two-step conventional strategy but after thermocycling, the two-step conventional strategy presented the worst performance among the experimental groups.

Solvation role of dimethyl sulfoxide on the interaction with dentin bonding systems after 30 months.

To determine whether DMSO could serve as an effective pretreatment to improve the mechanical properties and minimize the degradation of the adhesive interface, through the degree of conversion (DC) and bond strength to dentin of different categories of dentin bonding systems (DBSs) after 30 months. DMSO (0, 0.5, 1, 2, 5, 10vol%) were incorporated into four categories of DBSs: Adper Scotchbond Multipurpose (MP), Adper Single Bond 2 (SB), Clearfil SE Bond (CSE) and Adper Scotchbond Universal (SU). DC was evaluated by Fourier transform infrared spectroscopy (FTIR). For microtensile bond strength test (µTBS), 1 % DMSO were applied on dentin as pretreatment before DBSs. For SU, both strategies were tested. Specimens for µTBS were tested after 24h, 6 and 30 months. DC and µTBS data were subjected to two-way ANOVA and Tukey test (α<0.05). Incorporating 5 %/10 % DMSO increased the DC of CSE. Controversially, when combined with SU, 2 % and 10 % DMSO jeopardized the DC. Regarding µTBS, 1 % DMSO pre-treatment increased the bond strength for MP, SB, SU-ER and SU-SE. After 30 months, MP, SU-ER and SU-SE showed a decrease compared to baseline but remained higher than the control. DMSO pretreatment may be a useful strategy to improve the bond interface over time. Its incorporation seems to favor the non-solvated systems regarding DC while it seems to show long-term benefits for bond strength using 1 % DMSO for MP and SU systems.

Effect of Silica-Modified Aluminum Oxide Abrasion on Adhesion to Dentin, Using Total-Etch and Self-Etch Systems

This study compared the shear bond strength (SBS) and micromorphology of composite resin to human dentin after pre-treatment with silica-modified aluminum oxide air abrasion. Forty-six molar teeth were treated with either Scotchbond Multi-Purpose (SCMP) or Clearfil SE Bond (CLSE) adhesive. Buccal surfaces were pre-treated with the CoJet air abrasion system (SB), and lingual surfaces were controls. The adhesion of light-cured resin composite to the treated dentin surface was evaluated with SBS. After debonding, substrate surfaces were examined with an optical microscope for failure analysis. In addition, 15 molar teeth were sectioned and randomly assigned to one of five groups, according to the dentin surface pre-treatment and adhesive type, and examined with high-vacuum scanning electron microscopy/energy dispersive X-rays (SEM/EDS). The type of adhesive had a significant effect on SBS (p = 0.000); CLSE had the highest values. SB did not affect SBS (p = 0.090). SEM/EDS revealed residual aluminum and/or silicon on all dentin surfaces after SB, except for the control. Treatment with 32% phosphoric acid in the SCMP adhesive decreased the amounts of aluminum and silicon compared to SB dentin only, whereas CLSE resulted in similar quantities of aluminum and silicon as air-abraded dentin. The results of this study indicate that CLSE might have a higher bond strength to dentin than SCMP. Pre-treatment with SB does not appear to affect bonding strength.

Effect of Chlorhexidine-containing Etch-and-Rinse Adhesives on Dentin Microtensile Bond Strength after Biological Loading.

This study compared a 2%-CHX dentin pre-treatment with three CHX adhesives (experimentally admixed 0.1% CHX in primer or bonding agent, or industrially added 0.2% CHX in universal adhesive) by evaluating dentin bond strengths after biological loading in a fully automated artificial mouth model. The occlusal dentin of 50 freshly extracted human third molars was exposed, and the teeth were randomly assigned to 5 groups according to the adhesive protocol (n = 10): 1. control, Scotchbond Multipurpose (3M Oral Care; CTRL); 2. 2% CHX dentin pre-treatment (DENT); 3. 0.1% CHX experimentally admixed into the primer (PRIM); 4. 0.1% CHX experimentally admixed into the bonding agent (BOND); 5. Peak Universal Bond containing 0.2% CHX (Ultradent; PEAK). The teeth were restored with composite resin. Microtensile bond strength testing (bonding area 0.46 mm2 ± 0.04 mm2, crosshead speed 1 mm/min) was performed after 24-h storage in distilled water (baseline) or after 2-day biological loading with S. mutans (demineralization 1 h / remineralization 5 h). The mode of fracture was recorded and exemplary sticks were evaluated under SEM. CTRL exhibited significantly higher μTBS at baseline in comparison to PRIM (p = 0.000), BOND (p = 0.002), and PEAK (p = 0.000). After undergoing the caries model, CTRL demonstrated significantly lower μTBS compared to DENT (p = 0.000), PRIM (p = 0.008), and PEAK (p = 0.000). The same behavior was observed for BOND vs DENT (p = 0.000), PRIM (p = 0.003), and PEAK (p = 0.001). After biological loading, DENT (p = 0.041), PRIM (p = 0.000), and BOND (p = 0.000) exhibited significantly fewer adhesive fractures than CTRL. CHX addition to the primer protects dentin bond strength from declining after biological loading. Thus, it may offer some clinical advantage in terms of secondary caries inhibition around composite restorations. However, since loss of adhesion at baseline was less when 2% CHX was used as a dentin pre-treatment, it can be suggested as a safer option. so that bonding is not undermined by potential chemical interactions from CHX with the adhesives.

Effect of an aluminum chloride hemostatic agent on the dentin shear bond strength of a universal adhesive.

This study investigated the effect of an aluminum chloride hemostatic agent on the shear bond strength (SBS) of a universal adhesive to dentin. Eighty extracted human molars were trimmed at the occlusal dentin surfaces and divided mesiodistally. According to hemostatic agent application, specimens were randomly allocated into control (C) and hemostatic agent (Traxodent; H) groups. Each group was divided into 4 subgroups according to the adhesive system (n = 20): Scotchbond Multi-Purpose (SBER), Clearfil SE Bond (CLSE), All-Bond Universal etch-and-rinse mode (ALER), and All-Bond Universal self-etch mode (ALSE). SBS was measured for half of the specimens at 24 hours, and the other half were thermocycled in water baths (group T). Fracture surfaces were examined to determine the failure mode. The SBS was measured, and data were analyzed using 1-way analysis of variance, the Student's t-test, and the Tukey honestly significant difference test (p = 0.05). No significant differences in SBS were found between groups C and H for any adhesive system at 24 hours. After thermocycling, a statistically significant difference was observed between CT+ALSE and HT+ALSE (p < 0.05). When All-Bond Universal was applied to hemostatic agent-contaminated dentin, the SBS of H+ALSE was significantly lower than that of H+ALER (p < 0.05). The SBER subgroups showed no significant differences in SBS regardless of treatment and thermocycling. When exposed dentin was contaminated by an aluminum chloride hemostatic agent before dentin adhesive treatment, application of All-Bond Universal in etch-and-rinse mode was superior to self-etch mode.

Effect of modeling liquids on resin composite roughness and color parameters after staining and toothbrushing.

This study evaluated surface roughness, color stability, whitening index, and opacity of different types of modeling liquids for resin composite coating after exposure to staining and toothbrushing. Disc-shaped resin composite (Vittra APS, FGM) specimens were fabricated and divided into four groups (n = 10 each): control group, Composite Wetting resin (Ultradent Products), Adper Scotchbond Multipurpose adhesive (3M ESPE), and Adper Universal adhesive (3M ESPE). Surface roughness (Ra) was measured using a rugosimeter, while color stability (∆E00), whitening index (WI), and opacity (%) were measured using a spectrophotometer. Assessments were made at four time points: after polishing (baseline, T1), after immersion in red wine for 24 h (T2), and after 5,000 (T3) and 10,000 (T4) cycles of toothbrushing. Scanning electron microscopy images were captured to analyze the scratches created. The data were statistically analyzed by two-way repeated-measures analysis of variance and Tukey's honestly significant difference tests (α = .05). Modeling with the Wetting resin resulted in higher surface roughness (p < 0.05) and low color stability, which were attributable to porosities. Higher color change values were observed in the control group after staining. Both adhesives showed the lowest mean ΔE00 values (p < 0.005). WI decreased after staining, except with the use of the Universal adhesive (p < 0.005). The lowest opacity values were observed at baseline for all groups (p < 0.005). The Universal and Scotchbond adhesives had lower surface roughness, better color stability, higher WI, and the lowest opacity values after staining with red wine and toothbrushing.

Effect of Er, Cr: YSGG laser irradiation in the physics properties of different dentin bonding systems

The aim of this study was to evaluate the effect of Er, Cr: YSGG laser irradiation in the physics properties of the different dentin bonding systems (DBS) applied in dentin substrate.This study presented two variation factors: laser, divided into two levels (Er, Cr: YSGG [L] and Control - not irradiated [C]) and DBS divided into four levels (AdperTM Scotchbond Multipurpose [MP], AdperTM Single Bond 2 [SB], ClearfilTM SE Bond [CSE], ScotchbondTM Universal Adhesive [SU]). The response variables were water sorption/solubility (mg/mm3) [WS/WSB], degree of conversion (%) [DC], microtensile bond strength (MPa) [MS] and scanning electron microscopy [SEM] for descriptive analysis. After application of DBS over dentin substrate and before curing, in the L groups the irradiation was performed over the primer on MP and CSE and after primer/adhesive on SB and SU. After 7 days, the specimens were cut to obtain squared-shape blocks for WS/WSB, slices for one-year DC/MEV and sticks for one-year MS. The data was analyzed by two-way ANOVA, followed by Tukey test for multiple comparisons (p&lt;0.05).All irradiated groups presented lower WS/WSB than respective control groups. For DC, it was noted a significant difference only for DBS factor. However, laser irradiation promoted a significant drop in MS values, except for SU-L group. In SEM, greater penetration depth of resin tags were found for total-etch DBS, especially when laser irradiated.

Antibacterial effect, cytotoxicity, and bond strength of a modified dental adhesive containing silver nanoparticles.

This study aimed to evaluate the antibacterial effect, cytotoxicity, and microtensile bond strength of an adhesive system containing silver nanoparticles (NAg). NAg was synthesized and incorporated (500 and 1000ppm) into Scotchbond Multi-Purpose (SBMP) primer and bond. A microtensile bond test (μTBS) was performed after 24h and 1year. The adhesive interface was characterized using a confocal Raman microscope. The antibacterial activity was assessed using agar diffusion and biofilm inhibition assays (S. mutans). MTT assay was used to assess the cytotoxicity of NAg-conditioned culture media on human dental pulp stem cells (hDPSCs). The results were statistically analyzed using analysis of variance and Tukey's tests (α = .01). Incorporating 500 and 1000ppm of NAg in the SBMP did not affect the μTBS after 24h (p > 0.05). However, in the 1year evaluation, 500ppm presented the highest μTBS values (p < 0.05). The addition of NAg at 500 and 1000ppm in the primer and bond led to larger inhibition halos and colony-forming units than the control (p < 0.05). For the unpolymerized and polymerized groups, the combination of primer and bond presented the highest cytotoxic effects on hDPSCs (p < 0.05). In conclusion, incorporating 500 or 1000ppm of NAg into an etch-and-rinse adhesive system led to an antibacterial effect without altering the cytotoxicity. SBMP at 500ppm presented a higher μTBS at 1 year.