Alternative Aging Solutions to Accelerate Resin-Dentin Bond Degradation.

PURPOSE: This study evaluated the effect of aging solutions on the durability of resin-dentin bonds by means of microtensile bond strength (µTBS) and nanoleakage (NL) tests. MATERIALS AND METHODS: The adhesive system Adper Single Bond 2 (3M ESPE) was applied according to the manufacturer's instructions to the flattened occlusal surface of 40 extracted human molars. After bonding, teeth were sectioned to obtain bonded sticks (0.8 mm2 area) which were tested in tension immediately or after different storage periods (1 week, 1 month, or 6 months). Bonded sticks were kept immersed in 5 different solutions: 1) distilled water (DW); 2) 99.9% propionic acid (PA); 3) 99% acetic acid (AA); 4) 75% ethanol (ET), and 5) mineral oil (MO). To determine NL, bonded sticks from each experimental condition were immersed in silver nitrate and analyzed by SEM. Data were analyzed by two-way repeated measure ANOVA and Tukey's test (α=0.05). RESULTS: Faster degradation of bond strength (1 week) could be seen for AA and ET (p<0.05) in comparison with DW. Specimens stored in PA and DW showed bond strengths significantly reduced after one and six months, respectively (p<0.05). No degradation of the resin-dentin bond strengths was observed for specimens stored in MO (p>0.05). Nanoleakage increased for all groups except MO after storage. CONCLUSION: Propionic acid, acetic acid, and ethanol can be used as alternative aging solutions to more quickly obtain results on the bond resistance to degradation.

A new universal simplified adhesive: 36-Month randomized double-blind clinical trial.

STATEMENT OF THE PROBLEM: It is still debatable which technique should be used with universal adhesives, either etch-and-rinse (wet or dry) or self-etch strategy (with or without selective enamel etching). PURPOSE OF THE STUDY: To evaluate the 36-month clinical performance of Scotchbond Universal Adhesive (SU, 3M ESPE) in non-carious cervical lesions (NCCLs) using two evaluation criteria. METHODS/MATERIALS: Thirty-nine patients participated in this study. Two-hundred restorations were assigned to four groups: ERm: etch-and-rinse+moist dentin; ERd: etch-and-rinse+dry dentin; Set: selective enamel etching; and SE: self-etch. The same composite resin was inserted for all restorations in up to 3 increments. The restorations were evaluated at baseline and at 6-, 18-, and 36-months using both the FDI and the USPHS criteria. Statistical analyses were performed with Friedman repeated measures ANOVA by rank and McNemar test for significance in each pair (α=0.05). RESULTS: Eight restorations (ERm: 1; ERd: 1; Set: 1 and SE: 5) were lost after 36 months, but only significant for SE when compared with baseline (p=0.02 for either criteria). Marginal staining occurred in 6.8% of the restorations (groups ERm, ERd, and Set) and 17.5% of the restorations (group SE), with significant difference for each group when compared with baseline using the FDI criteria (p<0.04), while statistical significance was reached only for SE when compared with baseline using the USPHS criteria (p<0.03). Twenty-eight and 49 restorations were scored as bravo for marginal adaptation using the USPHS and FDI criteria, respectively, with significant difference for each group when compared with baseline (p<0.05). CONCLUSIONS: While there was no statistical difference among bonding strategies when a universal adhesive was used, there were signs of degradation when the universal adhesive was applied in SE mode. The FDI criteria remain more sensitive than the USPHS criteria, especially for the criteria marginal staining and marginal adaptation.

In-office bleaching with a two- and seven-day intervals between clinical sessions: A randomized clinical trial on tooth sensitivity.

OBJECTIVES: In-office bleaching is usually performed in 2-3 sessions with one-week interval. The impact of shorter interval times on tooth sensitivity has not been evaluated. This study aimed to compare the absolute risk of tooth sensitivity (TS) and colour change after in-office bleaching with a two- and seven-day intervals between sessions. METHODS: We selected for this randomized, single-blind study, 40 patients with colour C2 or darker. We performed two bleaching sessions with a 35% hydrogen peroxide gel with either a 1-week or 2-day interval. We recorded the TS up to 48 h with a VAS scale and the colour at baseline and 30 days after bleaching with a value-oriented shade guide and a spectrophotometer. The risk and intensity of TS were compared with the Fisher's exact test and two-way repeated measures ANOVA. Colour change (ΔSGU and ΔE) were evaluated by Student's t-test (alpha=5%). RESULTS: Approximately 60% of the participants reported TS (65% and 55% for the 7 and 2-day groups). A significant whitening of approximately 6 shade guide units was detected for both groups. No difference was detected between groups. CONCLUSIONS: The reduction of the interval between bleaching sessions from seven to two days reduced the treatment time without increasing the bleaching-induced TS (clinicaltrials.gov identifier: NCT1959789). CLINICAL SIGNIFICANCE: In-office bleaching with a 2-day interval did not increase the risk and intensity of bleaching-induced tooth sensitivity.

A new universal simplified adhesive: 6-month clinical evaluation.

STATEMENT OF THE PROBLEM: Multimode adhesives, which can be used as etch-and-rinse or as self-etch adhesives, have been recently introduced without clinical data to back their use. PURPOSE OF THE STUDY: To evaluate the 6-month clinical performance of Scotchbond Universal Adhesive (SU; 3M ESPE, St. Paul, MN, USA) in noncarious cervical lesions (NCCLs) using two evaluation criteria. METHODS/MATERIALS: Thirty-nine patients participated in this study. Two hundred restorations were assigned to four groups: SU-TEm: etch-and-rinse + moist dentin; SU-TEd: etch-and-rinse + dry dentin; SU-SEet: selective enamel etching; and SU-SE: self-etch. The composite resin Filtek Supreme Ultra (3M ESPE) was placed incrementally. The restorations were evaluated at baseline and after 6 months using both the World Dental Federation (FDI) and the United States Public Health Service (USPHS) criteria. Statistical analyses were performed with Friedman repeated measures analysis of variance by rank and McNemar test for significance in each pair (α = 0.05). RESULTS: Only four restorations (SU-SE: 3 and SU-TEm: 1) were lost after 6 months (p > 0.05 for either criteria). Marginal discoloration occurred in one restoration in the SU-SE group (p > 0.05 for either criteria). Only 2/200 restorations were scored as bravo for marginal adaptation using the USPHS criteria (one for SU-SE and one for SU-SEet, p > 0.05). However, when using the FDI criteria, the percentage of bravo scores for marginal adaptation at 6 months were 32%, 36%, 42%, and 46% for groups SU-TEm, SU-TEd, SU-SEet, and SU-SE, respectively (p > 0.05). CONCLUSIONS: The clinical behavior of the multimode adhesive does not depend on the bonding strategy at 6 months. The FDI evaluation criteria are more sensitive than the USPHS criteria. CLINICAL SIGNIFICANCE: At 6 months, the clinical behavior of the new multimode adhesive Scotchbond Universal was found to be reliable when used in noncarious cervical lesions and may not depend on the bonding strategy employed.

Perioperative use of an anti-inflammatory drug on tooth sensitivity caused by in-office bleaching: a randomized, triple-blind clinical trial.

OBJECTIVES: The aim of this study was to determine the effect of etoricoxib 60 mg on tooth sensitivity (TS) caused by in-office bleaching. MATERIALS AND METHODS: A triple-blind, parallel design, randomized clinical trial was conducted on 30 healthy, young adults who received either a placebo or etoricoxib. The drugs were administered 1 h before the bleaching process and after 24 h. Treatment was performed with 35 % hydrogen peroxide gel. The TS was recorded on three scales: VAS, 0-4, and 0-100. Shade evaluations were performed before and 30 days after bleaching with a visual shade guide and a spectrophotometer. The percentage of patients who reported TS at least once during treatment and the TS intensity were evaluated by Fisher's exact and Mann-Whitney U tests, respectively. Tooth color changes were evaluated by repeated measures ANOVA. RESULTS: There were no significant differences in the percentage of patients with TS, intensity of TS, and color between the groups. CONCLUSIONS AND CLINICAL SIGNIFICANCE: The anti-inflammatory medication etoricoxib 60 mg was unable to reduce the presence and intensity of TS. NCT01300780 (protocol No. 17838/2010).