Comparisons of ammonia- and water-based silver-containing solutions on dentin bonding and enzymatic activity: 1-yr evaluation.

OBJECTIVE: To evaluate the effects of an ammonia-based and a water-based silver-containing solutions on bonding performance and matrix-metalloproteinases (MMPs) activity of a universal adhesive to dentin after 1 year of artificial aging. METHODS: Mid-coronal dentin surfaces of 60 sound human molars were exposed and the following groups were formed according to the surface pre-treatment and etching mode of the universal adhesive (Zipbond Universal, SDI) (n = 10): G1) Zipbond in the self-etch mode (ZSE); G2) Riva Star (SDI) applied before ZSE; G3) Riva Star Aqua (SDI) applied before ZSE; G4) Zipbond in the etch-and-rinse mode (ZER); G5) Riva Star applied before ZER; G6) Riva Star Aqua applied before ZER. The specimens were sectioned and subjected to microtensile bond strength (µTBS) test at baseline (T0) and after 12 months (T12) of artificial storage. Scanning electron microscope (SEM) and energy dispersive spectroscopy analysis (EDS) were also conducted. Three additional molars per group were processed for the in situ zymography analysis at T0 and T12. Data were statistically analyzed (p < 0.05). RESULTS: Dentin pre-treatments and aging decreased bonding values, regardless of the etching mode (p < 0.05). No differences in µTBS were observed between the two silver-containing solutions, both at T0 and T12. Riva Star Aqua and etching significantly increased the MMPs activity, independent of the storage period (p < 0.05). SIGNIFICANCE: Dentin surface pre-treatment with silver-containing solutions negatively affects the bonding performances of resin composite restorations placed with a universal adhesive. However, the ammonia-based product Riva Star might show better stability in the long term, due to lower activation of MMPs.

Bond Strength to Lithium-Disilicate Ceramic after Different Surface Cleaning Approaches.

PURPOSE: To evaluate the effect of different lithium-disilicate (LiSi) glass-ceramic surface decontamination procedures on the shear bond strength (SBS) to resin cement. MATERIALS AND METHODS: Seventy CAD/CAM LiSi ceramic specimens (IPS e.max CAD, Ivoclar) were cut and sintered. Fifty specimens were treated with 5% hydrofluoric acid (HF) for 20 s, while 20 were left untreated. All 70 specimens were then contaminated with human saliva and try-in silicone paste. The following surface cleaning methods were investigated (n = 10): C: water rinsing (control); PA: 37% H3PO4 etching for 20 s; E: 70% ethanol applied for 20 s; CP: cleaning paste (Ivoclean, Ivoclar) brushed for 20 s; HFSEP: self-etching ceramic primer (Monobond Etch&Prime, Ivoclar) rubbed for 20 s; HF: 5% HF applied for 20 s or no HF etching prior to contamination; SEP: self-etching ceramic primer rubbed for 20 s and no HF etching prior to contamination. Composite cylinders were created and luted with an adhesive resin cement to the decontaminated surfaces. After storage for 24 h at 37°C, the SBS test was conducted. Two fractured specimens per group were observed under SEM to perform fractographic analysis. The data were statistically analyzed with p set at <0.05. RESULTS: The type of surface cleaning approach influenced bond strength (p < 0.001). HFSEP, SEP, and HF attained higher SBS (p < 0.001) compared to other groups. None of the approaches were able to completely remove contaminants from the ceramic surfaces. SEM images showed residual traces of contaminants on CP-treated surfaces. CONCLUSIONS: The self-etching ceramic primer enhanced bond strength to contaminated LiSi ceramic surfaces, irrespective of previous treatment with hydrofluoric acid.

The Influence of Different Bleaching Protocols on Dentinal Enzymatic Activity: An In Vitro Study.

This study aimed to investigate matrix metalloproteinase (MMP) activity in human dentin using in-situ and gelatin zymography, after at-home and in-office bleaching, related to their clinical exposure times. Dentin specimens (n = 5) were treated with 35% hydrogen peroxide (50 min per session/4 sessions), 10% carbamide peroxide (180 min/21 sessions), or no treatment. All were subjected to in-situ zymography. Dentin slices were, subsequently, obtained, covered with fluorescein-conjugated gelatin, and examined with confocal laser-scanning microscopy. The fluorescence intensity was quantified and statistically analyzed using one-way ANOVA and Bonferroni tests (α = 0.05). Furthermore, gelatin zymography was performed on protein extracts obtained from dentin powder (N = 8 teeth), treated with hydrogen peroxide or carbamide peroxide, with different exposure times (10/50 min for hydrogen peroxide; 252/1260 min for carbamide peroxide). The results of the in-situ zymography showed no statistical differences between the bleached specimens and the control group, with a medium level of gelatinolytic activity expressed in the dentin tubules. The results of gelatin zymography showed an increased expression of pro-MMP-9 in carbamide peroxide groups. The expression of pro-MMP-2 decreased in all the experimental groups. The bleaching treatments performed on the enamel of sound teeth do not influence dentinal enzymatic activity. However, when unprotected dentin tissue is bleached, matrix metalloproteinases are more expressed, particularly when carbamide peroxide is used, proportional to the exposure time.

Evaluation of Fiber Post Adhesion to Root Dentin Achieved with Different Composite Cements: 1-year In Vitro Results.

PURPOSE: To evaluate push-out bond strength (PBS) and interfacial nanoleakage (NL) of adhesively luted fiber posts using different composite cements and polymerization protocols. MATERIAL AND METHODS: 100 premolars were endodontically treated and assigned to the following groups (n=10): RelyX Universal light-cure (3M Oral Care); RelyX Universal self-cure (3M Oral Care); Maxcem Elite Chroma light-cure (Kerr); Maxcem Elite Chroma self-cure (Kerr); Calibra Universal light-cure (Dentsply Sirona); Calibra Universal self-cure (Dentsply Sirona); Multilink Automix light cure (Ivoclar Vivadent); Multilink Automix self-cure (Ivoclar Vivadent); Luxacore Z Dual light-cure (DMG); Luxacore Z Dual self-cure (DMG). Half of the teeth from each group were subjected to the PBS test after 24 h (T0), while the other half was tested after 12 months (T12) of artificial saliva aging. An additional 4 teeth per group were prepared for NL expression. PBS values were analyzed using multivariate ANOVA and Tukey's post-hoc test. NL scores were analyzed using chi-squared tests (α = 0.05). RESULTS: Statistical analysis revealed that the variables "cement" and "aging" significantly influenced PBS (p < 0.05), but not "polymerization" and "root region" (p > 0.05). Significantly lower PBS values (p < 0.05) were detected for the Calibra Universal groups compared to other cements, while the RelyX Universal groups performed equally well (p > 0.05) or better than other cements (p < 0.05). At T12, PBS values increased in the majority of groups, irrespective of root region (p < 0.05). Differences in NL expression were present at T0, and in general, the aging process increased marginal infiltration. CONCLUSION: Aging and choice of composite cement influenced PBS, while root region and polymerization protocol seemed to have no influence on posts' resistance to dislodgment.

The influence of selective enamel etch and self-etch mode of universal adhesives' application on clinical behavior of composite restorations placed on non-carious cervical lesions: A systematic review and meta-analysis.

BACKGROUND: To answer the PICOS question: "Is the risk of retention loss equal for SEE and SE approach when universal adhesives and composite restorations are indicated for restoring NCCLs?" METHODS: Web of Science, PubMed, Cochrane Central Register of Controlled Trials, Scopus, Scientific Electronic Library Online, LILACS, Google Scholar™ and OpenGrey were searched. Only randomized controlled clinical trials in which NCCLs were restored with composites and universal adhesives applied in SEE or SE mode were included. The articles were assessed for the risk of bias, after which meta-analyses were run (fixed-effects model was applied; heterogeneity was explored using Cochran Q test and I2 statistics; α = 0.05) and the certainty of evidence was assessed by the GRADE tool. RESULTS: Fifteen articles were included in qualitative, while 7 articles were included in quantitative analysis. Seven studies were judged as "low" risk of bias, while 8 were considered as "unclear" risk of bias. Statistically significant difference for retention were observed at 6- and 18/24 months (p = 0.05; OR=0.42, 95% CI [0.18, 0.99]; very low certainty of evidence and p = 0.007; OR=0.31, 95% CI [0.13, 0.72]; low certainty of evidence, respectively), favoring SEE approach. No other significant differences in clinical outcomes were observed between SEE and SE approach (very low certainty of evidence). SIGNIFICANCE: When restoring NCCLs, clinicians might consider applying universal adhesives in SEE mode since it could lead to more predictable retention compared to SE approach up to 2 years of follow-up.

Is clinical behavior of composite restorations placed in non-carious cervical lesions influenced by the application mode of universal adhesives? A systematic review and meta-analysis.

OBJECTIVE: To answer the following PICOS question: "Is the risk of retention loss, marginal discoloration, marginal adaptation and postoperative sensitivity (POS) equal for etch-and-rinse (EAR) compared to self-etch (SE) or selective-enamel etch (SEE) mode when restoring non carious cervical lesions (NCCLs) with universal adhesives?". METHODS: PubMed, Scopus, Web of Science, Cochrane Central Register of Controlled Trials, Scientific Electronic Library Online, LILACS, OpenGrey and Google Scholar™ were searched. Randomized controlled clinical trials in which resin composites and universal adhesives were used for restoration of NCCLs were considered. Cochrane Risk of Bias Tool was used to assess the risk of bias. Meta-analyses were performed using Revman; random-effects models were applied, and heterogeneity was tested using the I2 index. The significance level was set at p < 0.05. Certainty of evidence was assessed by GRADE tool. RESULTS: After screening, 20 articles were included in qualitative, while 14 articles were used for quantitative synthesis. Twelve studies ranked as "low", while 8 studies scored as "unclear" for risk of bias. At 12- and 18/24-months the risk for retention loss was higher for SE than for EAR groups (p = 0.005; RR = 0.22, 95% CI [0.08, 0.63],[moderate certainty of evidence and p = 0.0002; RR = 0.32, 95% CI [0.17, 0.58], moderate certainty of evidence, respectively). No significant differences were observed for marginal discoloration and adaptation (p > 0.05). The probability of POS occurrence was less in SE than in EAR groups (RR = 2.12, 95% CI [1.23, 3.64], moderate certainty of evidence). The certainty of evidence for other outcomes was scored as "low" or "moderate", depending on the follow-up period. SIGNIFICANCE: Using universal adhesives in EAR or SEE mode provides more predictable retention, while SE strategy reduces the risk of POS occurrence.