Effects of rotary brush active application on enamel etching patterns of self-etch adhesive systems.

Abstract.

Repair of aged bulk-fill composite with posterior composite: Effect of different surface treatments.

OBJECTIVE: In the present study, the ability of posterior resin composite to repair aged bulk-fill resin composite and vice versa were assessed by shear bond strength testing. MATERIALS AND METHODS: Resin composite substrates were aged and surfaces were abraded with abrasive papers, then bulk-fill substrates were repaired with posterior resin composite and vice versa using different surface treatments (no surface treatment [control]; etching with 37% phosphoric acid [H3 PO4 ] for 20 seconds; etching with 10% hydrofluoric acid [HF] for 20 seconds; etching with 37% H3 PO4 for 20 seconds + adhesive application; etching with 10% HF for 20 seconds + adhesive application; adhesive application only). Shear bond strengths (SBS) were then measured and surface roughness values (Ra) were determined. Cohesive strengths of nonaged resin composites were measured and used as reference groups. Resin composite surfaces after acid etching were evaluated by SEM. Data were analyzed using ANOVA and Fisher's LSD tests (P < .05). RESULTS: ANOVA showed that resin composite repair type did not affect SBS significantly (P = .850), while it showed that surface treatments significantly affected the SBS (P = .000). Only a combination of etching with 10% HF for 20 seconds with resin adhesive application provided similar SBS values with those of the positive control. CONCLUSIONS: It was concluded that the aged bulk-fill resin composite would be effectively repaired with conventional posterior resin composite or vice versa if proper repair protocol was deployed. CLINICAL SIGNIFICANCE: The combination of 10% HF etching and adhesive application would provide efficient repair strength when the aged bulk fill resin composite is repaired with conventional posterior resin composite or vice versa.

The durability of adhesion to Er,Cr:YSGG laser-irradiated enamel.

BACKGROUND AND AIMS: Adhesion durability of resin adhesives with Er,Cr:YSGG laser irradiated-enamel has been rarely investigated in the literature. Thus, the present study evaluated the influence of long-term water storage (12-month) on resin bond strength with the enamel irradiated with Er,Cr:YSGG laser irradiation deployed different settings. MATERIALS AND METHODS: The flattened enamel samples of 35 bovine teeth, which were embedded into acrylic blocks, were randomly divided into 7 groups (n = 5), according to surface treatments using Er,Cr:YSGG laser with different parameters 6 W/20 Hz, 6 W/35 Hz, 6 W/50 Hz, 3 W/20 Hz, 3 W/35 Hz, 3 W/50 Hz or no laser treatment (Bur-treating as a control). Adper Single Bond 2 was applied to the prepared enamel and the composites were placed and cured. Resin-enamel sticks with an approximate cross-sectional area of 0.8 mm2 were obtained, and microtensile bond strength (µTBS) tests were performed at 24-hour and 12-month of water storage after bonding. The µTBS data were analyzed with two-way ANOVA and Tukey tests (p < 0.05). RESULTS: 24-hour water storage after bonding, the µTBS to laser-irradiated enamel in the 6W/ 20 Hz group was significantly lower than those of bur-treated. However, 3 W/50 Hz showed significantly higher µTBS than those of bur-treated. Two-way ANOVA revealed that 12-month water storage did not influenced µTBS. CONCLUSION: It may be concluded that, initial bond strength to Er,Cr:YSGG laser irradiated-enamel might be significantly influenced by power and pulse frequency settings. However, resin bonding to laser-irradiated enamel was stable over 12-month water storage regardless of tested laser parameters.

Bonding performance of universal adhesives to er,cr:YSGG laser-irradiated enamel.

Universal adhesives have been recently introduced for use as self-etch or etch-and-rinse adhesives depending on the dental substrate and clinical condition. However, their bonding effectiveness to laser-irradiated enamel is still not well-known. Thus, the aim of this study was to compare the shear bond strength (SBS) of universal adhesives (Single Bond Universal; Nova Compo-B Plus) applied to Er,Cr:YSGG laser-irradiated enamel with SBS of the same adhesives applied in self-etch and acid-etching modes, respectively. Crown segments of sixty bovine incisors were embedded into standardized acrylic blocks. Flattened enamel surfaces were prepared. Specimens were divided into six groups according to universal adhesives and application modes randomly (n = 10), as follows: Single Bond Universal/acid-etching mode; Nova Compo-B Plus/acid-etching mode; Single Bond Universal/self-etching mode; Nova Compo-B Plus/self-etching mode; and Single Bond Universal/Er,Cr:YSGG Laser-etching mode; Nova Compo-B Plus/Er,Cr:YSGG Laser-etching mode. After surface treatments, universal adhesives were applied onto surfaces. SBS was determined after storage in water for 24 h using a universal testing machine with a crosshead speed of 0.5 mm min-1 . Failure modes were evaluated using a stereomicroscope. Data was analyzed using two-way of analyses of variances (ANOVA) (p = 0.05). Two-way ANOVA revealed that adhesive had no effect on SBS (p = 0.88), but application mode significantly influenced SBS (p = 0.00). Acid-etching significantly increased SBS, whereas there are no significant differences between self-etch mode and laser-etching for both adhesives. The bond strength of universal adhesives may depend on application mode. Acid etching may significantly increase bond strength, while laser etching may provide similar bond strength when compared to self-etch mode.

A review of ethanol wet-bonding: Principles and techniques.

Conventional water wet-bonding technique has been advocated by many scientists, but the excess water will induce suboptimal polymerization of dental adhesives, phase separation, and nanoleakage, which will influence the longevity of resin-dentin interfaces. Recent studies have put forward a new concept, ethanol wet-bonding. This technique can increase in dentin bond durability. This review focuses on the principles of ethanol wet-bonding, its surface treatment methods.

Influence of different Er,Cr:YSGG laser parameters on long-term dentin bond strength of self-etch adhesive.

The aim of the present study was to evaluate the effects of erbium, chromium: yattrium-scandium-gallium-garnet (Er,Cr:YSGG) laser frequency on microtensile bond strength (µTBS) of a self-etch adhesive to dentin after 15-month water storage. The Er,Cr:YSGG laser can safely be used on dental hard tissue. However, no study has compared the effects of Er,Cr:YSGG laser parameters and aging by water storage on the bonding effectiveness of self-etch adhesives to dentin. Thirty-five bovine teeth were randomly assigned to the following seven groups (n = 5): group I (diamond bur with high-speed handpiece (control)), group II (Er,Cr:YSGG laser 3 W/50 Hz), group III (Er,Cr:YSGG laser 3 W/35 Hz), group IV (Er,Cr:YSGG laser 3 W/20 Hz), group V (Er,Cr:YSGG laser 6 W/50 Hz), group VI (Er,Cr:YSGG laser 6 W/35 Hz), and group VII (Er,Cr:YSGG laser 6 W/20 Hz). Clearfil SE Bond was applied to the prepared dentin, and the composites were placed and cured. Resin-dentin sticks with an approximate cross-sectional area of 0.8 mm(2) were obtained, and bond strength tests were performed at 24 h and 15 months of water storage after bonding. Data were analyzed with Kruskal-Wallis and Mann-Whitney U tests (p < 0.05). Laser irradiation resulted in significantly lower bond strengths when compared to bur treating. Fifteen-month water storage reduced bond strength for all groups. There was no significant difference among the effects of different laser frequencies on bond strength. It can be concluded that Er,Cr:YSGG laser used at the tested parameters may alter the dentin bond durability of self-etch adhesive.

Effects of Er,Cr:YSGG laser parameters on dentin bond strength and interface morphology.

Previous studies have shown the effects of Er,Cr:YSGG laser irradiation on the dentin bond strength; but there are few reports that show the significance of the irradiation with different laser parameters on dentin bond strength and interface morphology. This in-vitro study attempted to evaluate the microtensile bond strength (µTBS) and interface morphology of resin-dentin interfaces, either followed by treatment with Er,Cr:YSGG laser irradiation with different parameters or not. The flattened dentin samples of 35 bovine teeth were embedded into acrylic blocks and randomly divided into seven groups according to surface treatments using Er,Cr:YSGG lasers with different parameters: 3 W/20 Hz, 3 W/35 Hz, 3 W/50 Hz, 1.5 W/20 Hz, 1.5 W/35 Hz, 1.5 W/50 Hz, or no laser treatment (n = 5). Composite buildups were done over bonded surfaces and stored in water (24 hours at 37°C). Specimens were sectioned into sticks that were subjected to µTBS testing and observed under FE-SEM. Control groups (27.70 ± 7.0) showed statistically higher values than laser-irradiated groups. There were no significant differences among laser groups. Despite that, increasing the pulse frequency yielded slightly higher bond strength. Depending on laser settings, Er,Cr:YSGG laser irradiation caused interfacial gaps and resin tags with wings morphology. With the parameters used in this study, Er,Cr:YSGG laser irradiation promoted morphological changes within resin-dentin interfaces and negatively influenced the bond strength of adhesive systems.

Effect of simplified ethanol-wet bonding on dentin bonding durability of etchand-rinse adhesives.

This in vitro study evaluated the effects of simplified ethanol-wet bonding technique on dentin bonding durability of two etchand-rinse adhesives to bovine dentin. Sixteen freshly extracted bovine incisors were divided into four groups according to bonding technique (water-wet or ethanol-wet bonding) and adhesive (Single Bond 2 or Prime & Bond NT). After etching and rinsing, dentin surfaces were left either water-moist or immersed in ethanol. Following adhesive application and composite build-up, bonded teeth were sectioned into sticks for microtensile bond strength (µTBS) testing conducted after 24-h and 12-month water storage. There were no significant differences in bond strength among the groups at 24 h. At 12 months, the bond strengths of adhesives to dentin were significantly decreased (p<0.05). Simplified ethanol-wet bonding did not improve the resin-dentin bonding durability of tested etch-and-rinse adhesives.

Letter to the Editor regarding "Depletion of water molecules during ethanol wet-bonding with etch and rinse dental adhesives".

I would like to comment on the above titled paper that recently published in Materials Science and Engineering C 33:21-27 (2013). I mentioned potential deficiencies in the study design. Then, I argued some statements made in the paper about interactions between bounded water around collagen molecules and resin infiltration, hence longevity of resin bonding. It is important to highlight these concerns regarding this paper so that readers are provided with another view of the ethanol wet-bonding concept.

Bond durability of contemporary adhesive systems to pulp chamber dentin.

Objective: The purpose of this study was to evaluate long-term bond strengths of dentin adhesive systems, which include one-step self-etch adhesive systems (Optibond All-in-one, Kerr; Adper Prompt L-POP, 3 M ESPE), a three-step etch-and-rinse adhesive (Optibond FL, Kerr) and two-step self-etch adhesive (AdheSE Bond, Ivoclar), applied to pulp chamber dentin surfaces after 12-month water storage by using microtensile bond strength (µTBS) test. Materials and methods: Dentin adhesive systems were applied to unprepared pulp chamber dentin surfaces according to manufacturer's directions, respectively (n = 5). After applying adhesive systems, composite buildups were done incrementally. Bond strengths to pulp chamber dentin surfaces were determined using µTBS test after water storage for 24 h and 12 month. Kruskal-Wallis analysis and Mann-Whitney U-test for pairwise comparisons were used to determine statistical differences in µTBS between the groups at a significance level of 5%. Results: There were no significant differences in µTBS between storage periods for tested adhesives regardless adhesive class. Conclusion: Bond durability of tested adhesive systems, including one-bottle self-etch adhesives with pulp chamber dentin surfaces, may be considered stable after 12-month water storage. Therefore, one-step self-etch, also called "user-friendly" adhesives may perform and traditional three-step etch-and-rinse adhesives in the long-term when used for bonding to pulp chamber dentin surfaces.