New Dual-cure Resin-based Material in Occlusal and Occluso-proximal Restorations of Primary Teeth: Results of a Randomized Clinical Trial.

Background: The clinical performance of new restorative materials must be evaluated before recommending its use in primary teeth. Aim: This randomized clinical trial evaluated the survival rates of restorations in single and occluso-proximal cavities of primary teeth performed with a new dual-cure resin-based material in comparison with a resin-modified glass ionomer cement after 12 months of follow-up. Materials and methods: A total of 107 restorations were placed in 27 children by one experienced pediatric dentist. Two materials were tested: Vitremer and a dual-cure resin-based material with (CentionN+Adh) and without (Cention N-Adh) adhesive system application. Two calibrated and blinded examiners evaluated the restorations at 3, 6, and 12-month. The longevity of the restorations was analyzed using Kaplan-Meier survival curves and Log-rank test (α = 5%). Results: The overall survival rates after 12-month were 81.9% for Vitremer, 70.4% for Cention N+Adh, and 66.7% for Cention N-Adh, which had the poorer performance (HR = 0.54; 95% CI= 0.31-0.95; p = 0.031). When considering the type of the cavities, the difference was significant only for occluso-proximal cavities when Cention N-Adh was used (HR = 0.46; CI = 0.26-0.81; p = 0.008). Conclusion: All evaluated materials are suitable for restoring occlusal cavities after selective caries removal. However, Cention N needs to be used with adhesive in occluso-proximal cavities. Clinical significance: Cention-N can be used for deciduous teeth restorations, with similar longevity rates as resin modified glass ionomer cements.Trial registration number RBR-9nqszr. How to cite this article: da Cunha CM, Wambier LM, Paris Matos TD, et al. New Dual-cure Resin-based Material in Occlusal and Occluso-proximal Restorations of Primary Teeth: Results of a Randomized Clinical Trial. Int J Clin Pediatr Dent 2022;15(1):38-46.

Universal adhesives and dual-cured core buildup composite material: adhesive properties.

OBJECTIVE: Dual-cured buildup composites and simplified light-cured adhesive systems are mixed with a chemical activator to prevent the incompatibility between them. To evaluate microshear bond strength (µSBS) and nanoleakage (NL) of three universal adhesives used under buildup composites using different curing modes, at baseline and after 6-months (6m). METHODOLOGY: Dentin specimens of 55 molars were assigned to: Clearfil Universal Bond[CFU], Prime&Bond Elect[PBE] and One Coat 7 Universal[OCU]. All-Bond Universal[ABU] and Adper Scotchbond Multi-Purpose[SMP] were used as controls. CFU, PBE, and OCU were: light-cured [LC], dual-cured using a self-curing activator [DC], and self-cured, using a self-curing activator and waiting for 20 min [SC]. Upon the application of the adhesive, transparent matrices were filled with a dual-cured buildup composite and light cured, then tested in mSBS. For NL, the specimens were submersed in ammoniacal silver nitrate and sectioned to observe under the SEM. Three-way ANOVA and Tukey's test were applied (α=0.05). RESULTS: OCU/LC-PBE/LC resulted in higher mean µSBS than ABU/LC. For SMP/DC higher mean µSBS were obtained than for both CFU/DC and OCU/DC (baseline). No universal adhesive was significantly affected by curing mode or storage time. CFU, PBE, and OCU did not undergo significant changes in any curing mode (p>0.05). NL (baseline) PBE/LC resulted in higher %NL compared to ABU/LC. SMP/DC resulted in higher %NL than CFU/DC-OCU/DC. CFU/LC/DC resulted in lower %NL than CFU/SC. PBE/SC resulted in lower %NL than PBE/DC. OCU/LC/SC showed lower %NL than OCU/DC. OCU showed significant lower %NL than CFU and PBE. All CFU groups, as well as OCU/SC, resulted in increased %NL at 6m when compared with baseline. CONCLUSION: For universal adhesives used in etch-and-rinse mode, self-cured activator and different curing modes did not influence µSBS. However, some interactions were observed for NL, but this influence was material-specific.

Universal adhesives and dual-cured core buildup composite material: adhesive properties

Abstract Dual-cured buildup composites and simplified light-cured adhesive systems are mixed with a chemical activator to prevent the incompatibility between them. Objective: To evaluate microshear bond strength (μSBS) and nanoleakage (NL) of three universal adhesives used under buildup composites using different curing modes, at baseline and after 6-months (6m). Methodology: Dentin specimens of 55 molars were assigned to: Clearfil Universal Bond[CFU], Prime&Bond Elect[PBE] and One Coat 7 Universal[OCU]. All-Bond Universal[ABU] and Adper Scotchbond Multi-Purpose[SMP] were used as controls. CFU, PBE, and OCU were: light-cured [LC], dual-cured using a self-curing activator [DC], and self-cured, using a self-curing activator and waiting for 20 min [SC]. Upon the application of the adhesive, transparent matrices were filled with a dual-cured buildup composite and light cured, then tested in mSBS. For NL, the specimens were submersed in ammoniacal silver nitrate and sectioned to observe under the SEM. Three-way ANOVA and Tukey's test were applied (α=0.05). Results: OCU/LC-PBE/LC resulted in higher mean μSBS than ABU/LC. For SMP/DC higher mean μSBS were obtained than for both CFU/DC and OCU/DC (baseline). No universal adhesive was significantly affected by curing mode or storage time. CFU, PBE, and OCU did not undergo significant changes in any curing mode (p>0.05). NL (baseline) PBE/LC resulted in higher %NL compared to ABU/LC. SMP/DC resulted in higher %NL than CFU/DC-OCU/DC. CFU/LC/DC resulted in lower %NL than CFU/SC. PBE/SC resulted in lower %NL than PBE/DC. OCU/LC/SC showed lower %NL than OCU/DC. OCU showed significant lower %NL than CFU and PBE. All CFU groups, as well as OCU/SC, resulted in increased %NL at 6m when compared with baseline. Conclusion: For universal adhesives used in etch-and-rinse mode, self-cured activator and different curing modes did not influence μSBS. However, some interactions were observed for NL, but this influence was material-specific.

18-month clinical evaluation of a copper-containing universal adhesive in non-carious cervical lesions: A double-blind, randomized controlled trial.

OBJECTIVE: This study aimed to evaluate the addition of copper nanoparticles (CuNp) on the clinical performance of a universal adhesive system used as etch-and-rinse (ER) and self-etch (SE). METHODS: 216 restorations were randomly placed in 36 subjects according to the following groups: ERcu = etch-and-rinse with 0.1% CuNp; ERct = etch-and-rinse without CuNp; SEcu = self-etch with 0.1% CuNp; SEct = self-etch without CuNp. Resin composite was placed incrementally and light-cured. The restorations were evaluated at baseline and 6, 12 and 18 months using the FDI and USPHS criteria. Statistical analyses were performed using appropriate tests (α = 0.05). RESULTS: The addition of CuNp did not increase the clinical performance (FDI / USPHS) of the universal adhesive tested after 18-month when applied in the ER mode (p > 0.05). The addition of CuNp in SE restorations increased the retention rate significantly and decreased the marginal discrepancies after 18 months (p < 0.05). CONCLUSION: The clinical performance of universal adhesive was significantly increased when applied in the SE mode with the addition of copper nanoparticles. CLINICAL RELEVANCE: This is the first study that demonstrates a slight improvement in the clinical performance of universal adhesive systems in non-carious cervical lesions when added CuNp in lower concentration.

Effect of MDP-containing Silane and Adhesive Used Alone or in Combination on the Long-term Bond Strength and Chemical Interaction with Lithium Disilicate Ceramics.

PURPOSE: To evaluate the effect of a silane and an adhesive containing MDP, used alone or combined in the same solution, on the microshear bond strength (µSBS) to lithium disilicate ceramics immediately and after 1-year water storage, and compare the bond strength results with the Raman spectra of the treated lithium disilicate surfaces. MATERIALS AND METHODS: A total of 30 CAD/CAM blocks of lithium disilicate (LD; IPS e.max CAD) were cut into four square sections (6 x 6 x 6 mm; n = 60 per group) and processed as recommended by the manufacturer. The LD specimens were divided into 12 groups according to the following independent variables: silane coupling agent (no silane; silane without 10-MDP [MBS, Monobond S]; silane with 10-MDP [MB+, Monobond Plus]) and adhesive + luting composite (no adhesive + Enforce; no adhesive + RelyX Ultimate; Prime & Bond Elect [PBE], a silane- and MDP-free universal adhesive + Enforce; Scotchbond Universal Adhesive [SBU], a silane- and MDP-containing universal adhesive + RelyX Ultimate). After each treatment, cylindrical, transparent matrices were filled with a luting composite and light cured. Specimens were stored in water (37°C for 24 h or 1 year) and submitted to the microshear bond strength (µSBS) test. The failure pattern and µSBS were statistically evaluated (α = 0.05). In addition, specimens were examined for chemical interaction using Raman spectroscopy. RESULTS: The use of the adhesive PBE alone showed higher mean µSBS compared with both groups with silane (MSB or MB+) without PBE (p < 0.001) at 24 h. The use of the SBU adhesive or MBS silane alone, as well as MB+ associated with SBU, showed higher mean µSBS (p < 0.001) at 24 h. After 1-year water storage, all groups showed a significant decrease in mean µSBS. However, the application of PBE or SBU associated with MB+ silane showed higher 1-year mean µSBS (p < 0.001). In terms of chemical interaction, when silane (MSB or MB+) was applied, only a slight decrease of Si-O peaks occurred. Otherwise, when PBE or SBU adhesives were applied, methacrylate peaks were only observed in the SBU groups. CONCLUSION: The best results in terms of bond strength after water storage were obtained when an MDP-containing silane was associated with a universal adhesive. The use of a simplified bonding protocol that includes either a silane or a universal adhesive is not recommended.

Acid Etching with Modified Phosphoric Acid to Increase the Longevity of the Bonded Interface.

PURPOSE: To evaluate the effect of three phosphoric acids modified with chlorhexidine (CHX), benzalkonium chloride (BAC), or proanthocyanidins (PRO) and one conventional phosphoric acid (CON) on the immediate (24 h; IM) and 1-year composite-dentin microtensile bond strength (µTBS) and nanoleakage (NL), using an etch-and-rinse adhesive. MATERIALS AND METHODS: A flat dentin surface was exposed on 28 caries-free extracted molars, which were then randomly assigned to four groups (n = 7). After etching and rinsing with one phosphoric acid per group, the adhesive (Adper Single Bond 2) was applied on a moist dentin surface. Composite buildups (Filtek Z350) were constructed incrementally and bonded stick specimens (0.8 mm2) were prepared and submitted to the microtensile test (0.5 mm/min) immediately (24 h) or after 1 year of water storage. For nanoleakage, 2 bonded sticks from each tooth at each storage period were immersed in 50 wt% ammoniacal silver nitrate, polished, and analyzed by SEM in backscattered mode. Data were submitted to a two-way ANOVA and Tukey's test (α = 0.05). RESULTS: After 1 year, stable µTBS values were observed only for the modified phosphoric acids (CHX, BAC, and PRO). Also, NL was more evident in the CON group than in the CHX, BAC and PRO groups (p < 0.05) after 1-year water storage. CONCLUSIONS: Compared to the control, the phosphoric acid etchants which contained protease inhibitors (CHX, BAC and PA) promoted the stability of composite-dentin microtensile bond strength and showed less nanoleakage after 1 year of water storage. They represent an effective way of prolonging the stability of the composite-dentin bonds without creating an additional bonding step.

Effect of self-curing activators and curing protocols on adhesive properties of universal adhesives bonded to dual-cured composites.

OBJECTIVES: To measure microshear bond strength (µSBS) and nanoleakage (NL) of self-etch universal adhesives under core buildup restorations using different curing protocols, at 24h and after 6-month water storage. METHODS: Middle dentin of 55 molars was divided into: Clearfil Universal Bond [CFU], Prime&Bond Elect [PBE], and One Coat 7 Universal [OCU]. All-Bond Universal [ABU] and Clearfil SE Bond [CSE] were used as control. CFU, PBE and OCU were: light-cured [LC], dual-cured [DC] and self-cured [SC]. Data were analyzed separately (two-way ANOVA), Tukey's test (α=0.05). RESULTS: µSBS: At 24h OCU/LC resulted in statistically higher µSBS than ABU. CSE/DC showed statistically higher µSBS than all DC adhesives. PBE/LC resulted in significant lower µSBS than the respective DC/SC modes (p<0.001). At 6-month, both CFU and PBE (LC/SC), resulted in a significant decrease in µSBS. µSBS for OCU/DC decreased significantly (p<0.001) compared to the respective LC/SC modes. NL: At 24h, ABU showed %NL similar to CBU/LC and OCU/LC (p>0.05). CSE/DC resulted in significantly higher %NL than OCU/DC but significantly lower than PBE/DC. CFU/LC/SC resulted in significantly lower %NL than CFU/DC. PBE/SC resulted in significant lower %NL than PBE/LC and PBE/DC. OCU/LC and OCU/DC resulted in significant lower %NL than OCU/SC (p<0.001). At 6-month ABU, CSE, CFU/LC and CFU/SC, resulted in a significant increase in %NL. SIGNIFICANCE: Self-cured activator and different curing protocols influenced µSBS and NL of self-etch universal adhesives, but this influence was material-dependent.

The role of copper nanoparticles in an etch-and-rinse adhesive on antimicrobial activity, mechanical properties and the durability of resin-dentine interfaces.

OBJECTIVES: To evaluate the effect of addition of copper nanoparticles at different concentrations into an etch-and-rinse adhesive (ER) on antimicrobial activity, Knoop microhardness (KHN), in vitro and in situ degree of conversion (DC), as well as the immediate (IM) and 2-year (2Y) resin-dentine bond strength (µTBS) and nanoleakage (NL). METHODS: Seven experimental ER adhesives were formulated according to the amount of copper nanoparticles incorporated into the adhesives (0 [control], 0.0075 to 1wt.%). We tested the antimicrobial activity of adhesives against Streptococcus mutans using agar diffusion assay after IM and 2Y. The Knoop microhardness and in vitro DC were tested after IM and 2Y. The adhesives were applied to flat occlusal dentine surfaces after acid etching. After resin build-ups, specimens were longitudinally sectioned to obtain beam-like resin-dentine specimens (0.8mm2), which were used for evaluation of µTBS and nanoleakage at the IM and 2Y periods. In situ DC was evaluated at the IM period in these beam-like specimens. Data were submitted to appropriate statistical analyses (α=0.05). RESULTS: The addition of copper nanoparticles provided antimicrobial activity to the adhesives only in the IM evaluation and slightly reduced the KHN, the in vitro and in situ DC (copper concentrations of 1wt.%). However, KHN increase for all concentrations after 2Y. After 2Y, no significant reductions of µTBS (0.06 to 1% wt.%) and increases of nanoleakage were observed for copper containing adhesives compared to the control group. CONCLUSION: Copper nanoparticles addition up to 0.5wt.% may provide antimicrobial properties to ER adhesives and prevent the degradation of the adhesive interface, without reducing the mechanical properties of the formulations.

Evaluation of Bond Strength, Marginal Integrity, and Fracture Strength of Bulk- vs Incrementally-filled Restorations.

PURPOSE: This study evaluated the effect of application technique and preparation size on the fracture strength (FS), microtensile bond strength (µTBS) and marginal integrity (MI) of direct resin composite restorations. MATERIALS AND METHODS: Conservative (5 × 2 × 2 mm) or extended (5 × 4 × 2 mm) preparations below the cementoenamel junction were performed in 140 human maxillary premolars (n = 70 per group). After adhesive application (XP Bond), half of each group was restored with the bulk technique (one 4-mm increment of Surefill SDR Flow plus one 1-mm horizontal capping layer of TPH3 [Spectrum TPH3 resin composite]) and half incrementally (TPH3 in three horizontal incremental layers, 1.5 to 2 mm each), all using a metal matrix band. After storage (24 h at 37°C), the proximal surfaces of each tooth were polished with Sof-Lex disks. For FS measurement, 60 restorations were mounted in a universal testing machine and subjected to a compressive axial load applied parallel to the long axis of the tooth, running at a crosshead speed of 0.5 mm/min. For µTBS testing, 40 teeth were longitudinally sectioned to obtain resin-dentin bonded sticks from the cavity floor (bonded area: 0.8 mm2). Specimens were tested in tension at 0.5 mm/min. The external marginal integrity of both proximal surfaces was analyzed using SEM of epoxy resin replicas. The µTBS, marginal integrity, and fracture resistance data were subjected to two-way ANOVA, and Tukey's post-hoc test was used for pair-wise comparisons (a = 0.05). RESULTS: Fracture resistance, microtensile bond strength, and marginal integrity values were not statistically significantly affected by application technique or preparation size (p = 0.71, p = 0.82, and p = 0.77, respectively). CONCLUSIONS: The use of a bulk-fill flowable composite associated with a conventional resin composite as a final capping layer did not jeopardize the fracture strength, bond strength to dentin, or marginal integrity of posterior restorations.

Laboratory Performance of Universal Adhesive Systems for Luting CAD/CAM Restorative Materials.

PURPOSE: To evaluate the microshear bond strength (µSBS) of several universal adhesive systems applied on five different indirect restorative materials. MATERIALS AND METHODS: Five CAD/CAM materials were selected: 1) indirect resin composite (LAV); 2) feldspathic glass ceramic (VTR); 3) leucite-reinforced glass-ceramic (EMP); 4) lithium disilicate ceramic (EMX); 5) yttrium-stabilized zirconium dioxide (CZI). For each material, 15 blocks were cut into 4 rectangular sections (6 × 6 × 6 mm) (n = 60 per group), and processed as recommended by the respective manufacturer. For each indirect material, the following adhesive systems were applied according to the respective manufacturer's instructions: 1) AdheSE Universal [ADU]; 2) All-Bond Universal (ABU); 3) Ambar Universal (AMB); 4) Clearfil Universal (CFU); 5) Futurabond U (FBU); 6) One Coat 7 Universal (OCU); 7) Peak Universal Bond (PUB); 8) Prime&Bond Elect (PBE); 9) Scotchbond Universal Adhesive (SBU); 10) Xeno Select (XEN, negative control). After the application of the adhesive system, cylinder-shaped transparent matrices were filled with a dual-curing resin cement (NX3) and light cured. Specimens were stored in water (37°C for 24 h) and tested in shear mode at 1.0 mm/min (mSBS). The failure pattern and µSBS were statistically evaluated (a = 0.05). RESULTS: LAV, VTR, and EMP showed a greater number of cohesive fractures than EMX and CZI (p < 0.0001). PUB was the only adhesive for which the mean µSBS reached the highest ranking of statistical significance for all five substrates. When each adhesive was compared across the five substrates, 8 out of 10 (ADU, ABU, AMB, CFU, OCU, PUB, PBE, and SBU) reached the statistically highest mean µSBS when applied on CZI. CONCLUSION: The specific chemical composition of universal adhesives was not the decisive factor in the bond strength values measured for different CAD/CAM indirect materials. There was a wide variability in mean µSBS when different universal adhesives were applied to the several CAD/CAM indirect materials. Most universal adhesives bonded well to air-abraded zirconia.

Protocolo das possibilidades técnicas de aplicação dos sistemas adesivos universais: revisão de literatura com relato de caso / Clinical strategies using universal adhesive systems: literature review with case report

Este relato de caso demonstra a utilização clínica de um novo sistema adesivo universal, Xeno Universal (Dentsply DeTrey, Alemanha) descrevendo quatro formas possíveis de aplicação: autocondicionante, com ou sem condicionamento seletivo do esmalte, ou com condicionamento ácido total, seguido da aplicação do adesivo sobre dentina seca ou úmida. Os adesivos universais de uma maneira geral são de fácil aplicação e versáteis, uma vez que o mesmo produto pode ter várias formas de aplicação, reduzindo o tempo clínico e em muitas situações a sensibilidade técnica. No entanto, mais estudos laboratoriais e clínicos que comprovem a eficácia deste novo adesivo universal em particular são necessários, antes que seu uso seja bem indicado aos cirurgiões-dentistas.

This case report describes the clinical application of a new universal adhesive system, Xeno Universal (Dentsply DeTrey, Germany) describing four application modes: self-etching, with or without selective enamel etching, or total etching followed by adhesive application on dry or moist dentin. Universal adhesive systems usually are versatile and easy to use, facilitating the operator, since the same product has several technical possibilities, thus reducing the operating time and the technique sensitivity. However, long-term laboratory studies and more clinical reports and/or clinical trials are needed to prove the quality of this new universal adhesive system, before dentists can start using them in their dental offices.

Mechanical properties and modeling of drug release from chlorhexidine-containing etch-and-rinse adhesives.

OBJECTIVES: To evaluate the effects of chlorhexidine (CHX) addition in different concentrations into simplified etch-and-rinse adhesives on the ultimate tensile strength (UTS), water sorption (WS), solubility (SO) and the rate of CHX release over time. METHODS: We added CHX diacetate to Ambar [AM] (FGM) and XP Bond [XP] (Dentsply) in concentrations of 0, 0.01, 0.05, 0.1 and 0.2 wt%. For UTS (n=10 for each group), adhesive specimens were constructed in an hourglass shape metallic matrix with cross-sectional area of 0.8 mm(2). Half of specimens were tested after 24 h and the other half after 28 days of water storage in tension of 0.5 mm/min. For WS and SO (n=10 for each group), adhesive discs (5.8 mm×1.0 mm) were prepared into a mold. After desiccation, we weighed and stored the cured adhesive specimens in distilled water for evaluation of the WS, SO and the cumulative release of CHX over a 28-day period. For CHX release (n=10 for each group), spectrophotometric measurements of storage solution were performed to examine the release kinetics of CHX. We subjected data from each test to ANOVA and Tukey' test (α=0.05). RESULTS: XP Bond adhesive showed significantly more WS and SO and lower UTS than Ambar. In general, the addition of CHX did not alter WS, SO and UTS of the adhesives. XP showed a higher CHX release than AM (p<0.05) in all concentrations and the final amount of CHX release was directly proportional to the initial CHX concentration added to the adhesives. After 28 days of water storage, approximately 20% of CHX was released from XP and 8.0-12.0% from AM. CONCLUSIONS: Addition of CHX to commercial adhesive is a feasible method to provide a controlled release of CHX over time without jeopardizing WS, SO and UTS of the adhesives. SIGNIFICANCE: Manufacturers should consider adding CHX to commercial adhesives to provide a controlled release of CHX over time.