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Objectives: This randomized controlled clinical trial evaluated the 3-year clinical performance of a hybrid (Clearfil AP-X; AP) and a flowable (Clearfil Flow FX; FX) resin composite in 98 non-carious cervical lesions. Methods:Twenty-two patients, 11 male and 11 female (mean age: 61.9 years, range: 29-78 years) regularly visiting the Nagasaki University Hospital, participated in the study. Each patient received both materials randomly. All restorations (48 restorations for AP and 50 restorations for FX) were placed in conjunction with an all-in-one system (Clearfil S 3 Bond) by one dentist. The restorations were blindly evaluated by two examiners at baseline, 6 months, 1, 2 and 3 years using modified USPHS criteria. The data were statistically analyzed using the Cochran's Q test and Fisher's exact test.Results: All the patients were examined at each recall. However, five restorations could not be evaluated at 3-year recall as two teeth had been extracted and three restorations had been lost. The only minor problem was the integrity of the enamel margin. The incidence and extent of marginal staining increased with time, but it was still superficial. Marginal staining occurred adjacent to 11 restorations for AP and 12 restorations for FX after 3 years. Neither lesion size nor depth had influence on marginal staining adjacent to each type of resin composite. There were no significant differences in the clinical performances between AP and FX for each variable. Conclusions:Under the protocol used in this study, both types of resin composite in conjunction with S 3 Bond demonstrated an acceptable clinical performance up to 3 years.

Objectives: This randomized controlled clinical trial evaluated the 2-year clinical performance of S 3 Bond (S3) and G-Bond (GB) in 108 non-carious cervical lesions. Methods:Twenty-three patients, 12 male and 11 female (mean age: 61.8 years, range: 30-79 years) regularly visiting the Nagasaki University Hospital of Medicine and Dentistry, participated in the study. Each patient received both materials randomly. All restorations (53 restorations for S3 and 55 restorations for GB) were placed by one dentist. The restorations were blindly evaluated by two examiners at baseline, 6 months, 1 and 2 years using modified USPHS criteria. The data were statistically analyzed using the Cochran Q test and Fisher's exact test.Results: One restoration of each material was lost during 2 years. The only minor clinical problem was the integrity of the enamel margin. Slight marginal staining occurred adjacent to 11 restorations of both S3 and GB. There was no significant difference in the clinical performance between S3 and GB for each variable. Conclusions:Under the protocol used in this study, S3 and GB have demonstrated an acceptable clinical performance up to 2 years.A systematic review of current clinical trials has revealed that one-step self-etch systems are not as effective as conventional three-step total-etch systems and two-step self-etch systems. 1)In order to address this problem, several newer one-step self-etch systems with a relatively thin adhesive layer were, approximately 10 μm, developed a few years ago.2-11)

Objectives: The incidence of non-carious cervical lesions (NCCLs) has been increasing.The clinical performance of resin composites in NCCLS was previously unsatisfactory due to their non-retentive forms and margins lying on dentin. In order to address this problem, a lot of effort has been put into developing new dentin adhesives and restorative techniques. This article discusses these challenges and the criteria used for evaluating clinical performance as they relate to clinical studies, especially long-term clinical trials. Polymerization contraction, thermal changes and occlusal forces generate debonding stresses at adhesive interfaces.Methods: In laboratory studies, we have investigated how these stresses can be relieved by various restorative techniques and how bond strength and durability can be enhanced. Lesion forms, restorative techniques, adhesives (adhesive strategies, bond strengths, bond durability, and the relationship between enamel and dentin bond strengths) were found to have a complex relationship with microleakage. With regard to some restorative techniques, only several short-term clinical studies were available.

This study investigated the effect of a caries-detecting solution on the tensile bond strength（TBS）to sound bovine dentin -which was either rinsed thoroughly of or contaminated with the caries-detecting solution.Caries Detector（1.0％ acid red in propylene glycol）was applied on flat dentin surfaces for 10 seconds, rinsed, and dried with syringe air. In another group, Caries Detector was not rinsed but air-dried. Then, the surfaces were treated with one of the following adhesive systems: Clearfil Protect Bond, Clearfil SE Bond, One-Up Bond F, or Single Bond. Furthermore, an ingredient of Caries Detector, either 1.0％ acid red aqueous solution or propylene glycol, was applied to evaluate the effect of each component. In the control groups, Caries Detector was not applied to the dentin surfaces. Finally, a resin composite was light-cured and the TBS measured. Fractured specimens and treated dentin surfaces were observed by SEM. Caries Detector did not reduce the tensile bond strength of any adhesive system（p＞0.05）when rinsed thoroughly. On the other hand, when dentin surface was contaminated with Caries Detector, TBS decreased significantly with Clearfil SE Bond and Single Bond. As for the ingredients of Caries Detector, the effect of acid red on TBS was not significant, but that of propylene glycol was significant.