No abstract available.

No abstract available.
Dentistry

No abstract available.
Dentistry ; Endodontics ; Korea

No abstract available.

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Electronics ; Electrons ; Publications

No abstract available.
Dentistry ; Endodontics ; Peer Review

No abstract available.
Dentistry ; Endodontics ; Peer Review

OBJECTIVES: This study investigated the effects of the color components of light-cured composite resin before and after polymerization on degree of conversion (DC) and biaxial flexural strength (FS). MATERIALS AND METHODS: Four enamel shades (A1, A2, A3, A4) and two dentin shades (A2O, A3O) of Premisa (Kerr Co.) and Denfil (Vericom Co.) were evaluated on their CIE L*, a*, b* color components using the spectrophotometer before curing, after curing and at 7 day. The DC of same specimens were measured with Near-infrared spectrometer (Nexus, Thermo Nicolet Co.) at 2 hr after cure and at 7 day. Finally, the FS was obtained after all the other measurements were completed at 7 day. The correlations between each color component and DC and FS were evaluated. RESULTS: The light-curing of composite resin resulted in color changes of Premisa in red-blue direction and Denfil in green-blue direction. The DC and FS were affected by product, time and shade (3-way ANOVA, p < 0.05) and product and shade (2-way ANOVA, p < 0.05), respectively. Premisa only showed a significant correlation between the DC and CIE a* component - before and after polymerization (Pearson product moment correlation, p < 0.05). The FS of Premisa showed significant negative correlations with CIE a* and CIE b* components. CONCLUSIONS: The DC and FS of the light-curing composite resin were affected by the color components of the material before and after polymerization.
Dental Enamel ; Dentin ; Polymerization ; Polymers

OBJECTIVES: In most retrospective studies, the clinical performance of restorations had not been considered in survival analysis. This study investigated the effect of including the clinically unacceptable cases according to modified United States Public Health Service (USPHS) criteria into the failed data on the survival analysis of direct restorations as to the longevity and prognostic variables. MATERIALS AND METHODS: Nine hundred and sixty-seven direct restorations were evaluated. The data of 204 retreated restorations were collected from the records, and clinical performance of 763 restorations in function was evaluated according to modified USPHS criteria by two observers. The longevity and prognostic variables of the restorations were compared with a factor of involving clinically unacceptable cases into the failures using Kaplan-Meier survival analysis and Cox proportional hazard model. RESULTS: The median survival times of amalgam, composite resin and glass ionomer were 11.8, 11.0 and 6.8 years, respectively. Glass ionomer showed significantly lower longevity than composite resin and amalgam. When clinically unacceptable restorations were included into the failure, the median survival times of them decreased to 8.9, 9.7 and 6.4 years, respectively. CONCLUSIONS: After considering the clinical performance, composite resin was the only material that showed a difference in the longevity (p < 0.05) and the significantly higher relative risk of student group than professor group disappeared in operator groups. Even in the design of retrospective study, clinical evaluation needs to be included.
Acrylic Resins ; Glass ; Humans ; Longevity ; Retrospective Studies ; Silicon Dioxide ; United States Public Health Service