Effect of silver diamine fluoride on the longevity of the bonding properties to caries-affected dentine.

OBJECTIVES: This study aimed to evaluate the adhesive properties in dentine after the application of silver diamine fluoride (SDF) on carious dentine lesions immediately and after 2 years of water storage. METHODS: 96 human molars used were subjected to artificial dentine caries production, and then randomly divided into 12 experimental groups according to 1. application of an SDF solution (carious dentine lesion without SDF treatment [control], with 12 % silver diamine fluoride [SDF 12 %] or 38 % silver diamine fluoride [SDF 38 %]); 2. Universal adhesives (Clearfil Universal Bond Quick [CUQ] and Single Bond Universal [SBU]); 3. adhesive strategy (etch-and-rinse [ER] and self-etch [SE]). After restoration, the specimens were sectioned and submitted to the microtensile bond strength test (µTBS) and energy-dispersive X-ray spectrometry analysis (SEM/EDX). All tests were performed immediately and after 2 years of water storage. Data from the µTBS were analyzed using four-way ANOVA and Tukey's test (α = 0.05). RESULTS: Only the interaction of factors 'SDF' vs 'time' was significant (p = 0.03). After 2 years of storage, the groups where SDF was applied showed higher µTBS values compared to the control group. No significant decrease in µTBS values was observed for SBU when comparing immediate and 2-year results, but a significant reduction in µTBS values was observed after 2 years for CUQ. CONCLUSION: Independent of the adhesive strategy, the use of SDF may be a promising alternative to maintain the bonding of universal adhesives to carious dentinal lesions. CLINICAL SIGNIFICANCE: This study may clarify and support clinicians regarding the longevity of resin-based restoration in caries-affected dentine treated with silver diamine fluoride.

Prolonged application time effects on universal adhesives in non-carious cervical lesions: An 18-month split mouth randomized clinical trial.

OBJECTIVE: This double-blind, split mouth randomized clinical trial aimed to assess the clinical performance of Clearfil Universal Bond Quick (CBUq) universal adhesive under different application times (no waiting and waiting) compared to Clearfil SE Bond adhesive in non-carious cervical lesions (NCCLs) over 18 months. METHODS: One hundred and eighty-three restorations were distributed randomly into three groups based on the adhesive system and waiting time: CUBq without waiting time (CUBq-NW), CUBq with a 20 s waiting time (CUBq-W), and CSE with a 20 s waiting time. After placement, restorations were evaluated after 18 months using the International Dental Federation (FDI) and United States Public Health Service (USPHS) criteria. Statistical analyses involved Friedman repeated measures analysis of variance and Wilcoxon tests, with a significance level set at 5 %. RESULTS: Over the 18-month period, no restorations were lost across the tested groups. Marginal adaptation evaluation indicated minor discrepancies in 21 restorations (8 CUBq-NW, 6 CUBq-W, and 7 CSE). There were no significant differences observed among the three groups following the 18-month clinical assessment (p > 0.05). Only two restorations showed marginal discoloration after 18 months (1 CUBq-NW and 1 CSE). CONCLUSIONS: The application of Clearfil Universal Bond Quick using either the "waiting" or "no-waiting" technique exhibited excellent clinical results in NCCLs during the 18-month follow-up period, demonstrating comparable performance to Clearfil SE Bond in all assessed outcomes. CLINICAL SIGNIFICANCE: The findings suggest that the new universal adhesive applied using the no-waiting technique demonstrates promising clinical performance when compared to conventional application methods. TRIAL REGISTRATION: ClinicalTrials.gov identifer RBR-69p7mpr.

Effect of the Absence of HEMA on the Bonding Properties of Universal Adhesive Systems Containing 10-MDP: An In Vitro Study.

OBJECTIVES: To evaluate the absence of 2-hydroxyethyl methacrylate (HEMA) on the adhesive properties with enamel and dentin of universal adhesive systems containing 10-methacryloyloxydecyl dihydrogen phosphate (MDP). METHODS AND MATERIALS: One hundred and twelve caries-free third molars were used to test adhesion to dentin (n=64) and enamel (n=48). For each substrate, teeth were divided into eight experimental groups: four different adhesives each using two adhesive strategies. The adhesives used were: (1) Scotchbond Universal (SBU, 3M Oral Care, St Paul, MN, USA) as a HEMA-containing universal adhesive; (2) Gluma Bond Universal (GBU, Kulzer, Hanau, Germany); (3) Solare Universal Bond (SUB, GC, Tokyo, Japan); and (4) Zipbond Universal (ZIP, SDI, Victoria, Australia) as HEMA-free universal adhesives. The adhesive strategies used were etch-and-rinse (ER) and self-etch (SE). For dentin tests, the occlusal third of the crown of all teeth was removed and an adhesive protocol was applied. After completing the restoration, specimens were sectioned into bonded sticks (0.8 mm 2) and tested for microtensile bond strength (µTBS), in situ degree of conversion (DC), and nanoleakage (NL) by scanning electron microscopy. For enamel tests, teeth were sectioned into four parts (buccal, lingual, and proximal), and an adhesive protocol was applied. After completing the restoration, the specimens were tested for their microshear bond strength (µSBS). For in situ degree of conversion (DC) and nanoleakage (NL) evaluation of enamel, the specimens were sectioned in slices to be evaluated. The data for each substrate were subjected to two-way ANOVA and Tukey's test (α=0.05) for each property evaluated. RESULTS: The SBU and ZIP adhesives showed the highest µSBS, and DC (dentin and enamel) and lower NL (dentin) values compared to GBU and SUB (p=0.001). However, SBU showed better results in terms of µTBS and µSBS (SE strategy), and DC (dentin and enamel) than ZIP. Strategy ER presented higher values of µTBS and µSBS when compared to strategy SE (p=0.001), except for SBU. CONCLUSION: The effect of the absence of HEMA in commercial universal adhesive systems on enamel and dentin adhesive properties appears to be material-dependent.

Effect of the Viscosity and Application Time of Different Phosphoric Acids on the Bond Strength and Nanoleakage of Fiber Posts to Root Dentin.

PURPOSE: To evaluate the effect of application time and viscosity of meta-phosphoric acid (MPA) and ortho-phosphoric acid (OPA) on the push-out resin-dentin bond strength (PBS) and nanoleakage (NL) at the adhesive-root dentin interface. METHODS AND MATERIALS: Ninety-six roots of premolars were endodontically prepared and randomly assigned into groups according to the (i) acid (OPA and MPA), (ii) viscosity (gel and liquid), and (iii) application time (7 and 15 seconds). Fiber posts were cemented to the roots, which were then transversally sectioned into serial slices. The slices (cervical, medium, and apical) were subjected to PBS or NL. Analysis of the dentin etching pattern was performed using scanning electron microscopy (SEM). The PBS (MPa) and NL (%) data were subjected to three-way repeated-measures analysis of variance (ANOVA) and Tukey's test (α=0.05). RESULTS: The cross-product interaction was significant for both PBS and NL (p<0.001). No significant difference in the PBS was observed with the use of OPA compared to MPA (p>0.05). Higher PBS values were observed in the groups etched for 15 seconds compared to 7 seconds, regardless of the acid, viscosity, or root third (p<0.05). Lower NL was observed for MPA etching when compared to OPA etching (p<0.05), and these values were not affected by increasing the application time or acid viscosity (p>0.05). A more pronounced etching pattern was observed with OPA than MPA regardless of the acid viscosity. CONCLUSION: The use of 40% meta-phosphoric acid promoted adequate bond strength without increasing dentin demineralization or void spaces in the hybrid layer.

Influence of Irradiance and Exposure Times on the Mechanical and Adhesive Properties of Universal Adhesives with Dentin.

OBJECTIVES: This study evaluated the influence of irradiance/exposure time on the Knoop hardness (KHN) and polymer cross-linking density (PCLD), as well as microtensile bond strength (µTBS), nanoleakage (NL), and in situ degree of conversion (DC) of universal adhesives. METHODS AND MATERIALS: Two universal adhesive systems, Clearfil Universal Bond Quick (CUQ) and Scotchbond Universal Adhesive (SBU), were light-cured using various irradiance/exposure times: 1400 mW/cm2 for 5 s (1400*5); 1400 mW/cm2 for 10 s (1400*10); 3200 mW/cm2 for 5 s (3200*5); and 3200 mW/cm2 for 10 s (3200*10). Adhesive disks from each group were used to measure PCLD by KHN. One hundred and twenty-eight human molars were randomly assigned to 16 groups according to the following variables: adhesive system vs adhesive strategies vs radiance/exposure times. After restoration, specimens were sectioned into resin-dentin sticks and tested for µTBS, NL, and DC. The data from PCLD (%), KHN, µTBS (MPa), NL (%), and DC (%) data were subjected to ANOVA and Tukey's test (α=0.05). RESULTS: Significant reductions in KHN, µTBS, and DC (p=0.00001) values and an increase in NL and PCLD (p=0.00001) values were observed for 3200*10 when compared with other groups. Higher KHN, µTBS, and DC (p=0.000001) values were observed for 3200*5 in comparison with the other groups. The 1400*5 (7 J/cm2) and 1400*10 (14 J/cm2) groups showed intermediate values (p=0.000001). CONCLUSION: Although similar results in terms of hardness, polymer cross-linking density and nanoleakage were observed when 5 seconds at 3200 mW/cm2 and 10 seconds at 1400 mW/cm2 groups were compared, the use of higher irradiance (3200 mW/cm2) for only 5 seconds showed better results in terms of bond strength and degree of conversion for both universal adhesives to dentin. The prolonged exposure time (10 seconds) at the higher irradiance (3200 mW/cm2) showed the worst results.

Effects of Adjacent Tooth Type and Occlusal Fatigue on Proximal Contact Force of Posterior Bulk Fill and Incremental Resin Composite Restoration.

OBJECTIVES: To measure the proximal contact force in newtons (N) between incremental and bulk fill class II resin composite restorations and implant molar teeth or adjacent premolar teeth with simulated periodontal ligament. METHODS: The model used was created with a typodont first molar tooth with two bilateral occlusal-proximal class II cavities, an adjacent tooth simulating an implanted molar tooth (Titamax CM, Neodent, Curtiba, PR, Brazil) and a premolar with simulated periodontal ligament. Two resin composite restorative techniques were used: Inc-Z350XT, (Filtek Z350, 3M Oral Care, St. Paul, MN, USA) inserted incrementally and Bulk-OPUS, (Opus Bulk Fill APS, FGM, Joinville, SC, Brazil) high viscosity bulk fill resin composite (n=10). As a control, a typodont having intact teeth without restorations was used. After the restorative procedure, each specimen was radiographed using a digital system (Dürr Dental, Bietigheim-Bissingen, Germany). The proximal contact force (N) was measured using dental floss with a microtensile machine (Microtensile ODEME, Luzerna, SC, Brazil). The specimens were then subjected to mechanical fatigue cycling to simulate 5 years of aging. All the parameters were measured after aging. The X-rays were blindly qualitatively analyzed by two operators to identify the loss of proximal contact. One-way ANOVA was used for comparing the initial contact force between restored and intact teeth. Two-way ANOVA followed by Tukey testing was performed for contact area data and for the contact force/contact area ratio. The proximal contact force data were analyzed using one-way repeated measurement ANOVA followed by Tukey testing (α=0.05). The X-ray proximal contact analyses were described by the frequency. RESULTS: The initial proximal contact force was similar for intact and restored teeth. The contact force and contact area with the molar were significantly higher than with the premolar; however the contact force/contact area ratio was similar for all tested groups. The bulk fill technique showed a contact force similar to the incremental filling technique. Fatigue resulted in a significant reduction in the proximal contact force (p<0.001), irrespective of the region analyzed or restorative material used. The digital X-rays detected no alteration in the proximal contact after occlusal fatigue. CONCLUSIONS: Larger contact area resulted in higher proximal contact force. Proximal contact force decreased with 5 years of simulated occlusal fatigue. The bulk fill technique showed a proximal contact force similar to that of the incremental filling technique.

Effect of the Photo-initiator System Contained in Universal Adhesives on Radicular Dentin Bonding.

CLINICAL RELEVANCE: The photo-initiator system based on an advanced polymerization system may be an alternative that can be used to overcome the disadvantages of radicular dentin, especially for the apical third. SUMMARY: Objectives: The purpose of this study was to evaluate the effects of universal adhesives with different photo-initiator systems applied in etch-and-rinse (ER) and self-etch (SE) modes on dentin interaction (push-out bond strength [PBS], nanoleakage [NL], and degree of conversion [DC] within the hybrid layer) in the different root thirds after fiber post cementation.Methods and Materials: Roots of endodontically prepared human premolars were randomly divided into six groups according to one of three adhesive systems (Scotchbond Universal [SBU], Ambar Universal [AMB], and Ambar Universal APS [AMB-APS]) and two adhesive strategies (ER and SE) for each system. Posts were cemented, and PBS was tested at 0.5 mm/min. The NL was evaluated by scanning electron microscopy. DC was measured using micro-Raman spectroscopy. The data were analyzed by three-way analysis of variance and Tukey tests (α=0.05).Results: AMB-APS showed similar performance in all root thirds (p>0.05) and higher values of DC, especially in the apical third (p<0.0001). AMB and SBU showed the lowest values in the apical third (p<0.0001).Conclusions: The APS photo-initiator system contained in universal adhesives is a feasible alternative for improving radicular bonding procedure.

Bonding Performance of Universal Adhesive Systems Applied in Etch-and-Rinse and Self-Etch Strategies on Natural Dentin Caries.

OBJECTIVE: This study investigated the bonding performance of three universal adhesive systems applied using etch-and-rinse (ER) or self-etch (SE) strategies on natural dentin caries. MATERIALS AND METHODS: Sixty human third molars were selected for this study: 30 naturally carious (CAD) and 30 sound (SD) teeth. The dentin surfaces were exposed, and teeth were randomly assigned to each evaluated adhesive system: Scotchbond Universal (SBU), Futurabond U (FBU), and Prime&Bond Elect (PBE) and an adhesive strategy: ER or SE. The adhesive systems were applied following the manufacturer's instructions, and the teeth were restored using a resin composite (Filtek Supreme Ultra, 3M). After 24 hours (distilled water at 37°C), samples were sectioned and evaluated using microtensile bond strength analysis (µTBS), micro-Raman spectroscopy to evaluate the degree of conversion within the hybrid layer (DC), and scanning electronic microscopy (SEM) to describe the morphology of the hybrid layer. The µTBS and DC data were analyzed using three-way analysis of variance and Tukey's test for means comparison (α=0.05). The SEM images were analyzed qualitatively. RESULTS: Reduced µTBS values were observed when comparing CAD with SD, regardless of adhesive system or strategy (p<0.0001). SBU showed statistically higher µTBS for both dentin substrates and strategies (p<0.0001). Furthermore, SBU showed greater integrity of the hybrid layer and resin tag formation compared with FBU and PBE. Mean µTBS values for FBU were higher for SD in the SE mode, whereas higher mean µTBS values were observed for CAD in the ER mode, both compared with PBE (p<0.001). CONCLUSION: Bonding performance is reduced on a caries-affected substrate. The ER strategy was not able to improve the bonding performance on natural CAD for universal adhesive systems. Improved bonding performance was obtained when using the Scotchbond Universal system.

Three-Year Effects of Deproteinization on the In Vitro Durability of Resin/Dentin-Eroded Interfaces.

OBJECTIVE: To evaluate the effect of sodium hypochlorite on the immediate and three-year bonding properties of a resin-eroded dentin interface produced by one of two adhesive strategies. METHODS AND MATERIALS: Forty-eight molars were randomly assigned to six experimental groups, according to the combination of the adhesive strategy (etch-and-rinse and self-etch) and the dentin surface (control groups without erosion, eroded dentin surface [ED], and eroded dentin surface + NaOCl 5.2% [ED + NaOCl]). After completing restoration, specimens were stored in water (37°C) for 24 hours and then sectioned into resin-dentin beams (0.8 mm2) to be tested under tension (0.5 mm/min) immediately thereafter or after three years of water storage. To assess nanoleakage (NL), specimens were immersed in silver nitrate solution and examined by scanning electron microscopy at both time points. The dentin-etching pattern was examined under a scanning electron microscope. Data were subjected to appropriate statistical analysis (α=0.05) Results: In both strategies, a more pronounced and significant reduction of the microtensile bond strength (µTBS) values was observed for the ED groups ( p=0.0001) after three years. However, in the ED + NaOCl group, µTBS values were maintained after three years of water storage. Furthermore, application of NaOCl to eroded dentin significantly reduced the immediate NL values and also preserved these values after three years of water storage for both adhesive strategies ( p>0.05). When considering the ED group, a superficial removal of the smear layer and enlarged lumen tubules in comparison to control were present. However, for ED + NaOCl, there was a total removal of the smear layer and significant numbers of collagen fibrils were exposed. CONCLUSION: The use of NaOCl may maintain the long-term stability of a resin-eroded dentin interface formed by etch-and-rinse and self-etch adhesives.

Using CAD/CAM-Modified Correlation Mode to Produce Laminate Veneers: A Six-Month Case Report.

The expectation of an esthetically harmonious smile increases the level of difficulty when treating patients. Laminate veneers stand out as a treatment option for cosmetic rehabilitation in clinical practice, as they are a more conservative procedure and mimic dental structures. These laminate veneers are generally made with different techniques; the most common requires an impression of the prepared tooth, an impression antagonist, fabrication models, and extensive laboratory time. The computer-aided design/computer-aided manufacturing (CAD/CAM) system optimizes the fabrication of prosthetic structures, reducing chairside time and promoting good esthetic results. Thus, the purpose of this case report is to present the esthetic result of multiple CAD/CAM manufactured laminate veneers using a new self-etching glass ceramic primer with a lithium disilicate ceramic, using the modified correlation and biogeneric modes.

Four-year Follow-up of a Direct Anatomical Fiber Post and Esthetic Procedures: A Case Report.

Knowledge about the stability of fiber posts cemented in widened canal spaces over time is scarce in the literature. Thus, the purpose of this case report was to evaluate the performance of a direct anatomical post in a widened canal space over the course of four years. The present clinical case describes the rehabilitation of a widened canal space using a direct anatomical post (a resin composite combined with a prefabricated glass fiber post) associated with an all-ceramic crown and other restorative procedures. This technique is easy to perform and may solve some of the problems associated with the cementation of a poorly adapted fiber post in a widened canal space.