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.

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.

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.

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.

The purpose of the present study was to evaluate the direct and indirect composite restorations which had been placed for 1 year.

The composite restorations which had been placed between 1999. Mar and 1999, Dec was evaluated after 1 year. For direct restorations, Spectrum (Dentsply, USA) and Z100 (3M, USA) were used in the anterior teeth and Surefil (Dentsply, USA) were used. For class V restorations of anterior and posterior teeth, Spectrum was used. For indirect restorations, Targis/Vectris system (Vivadent/Ivoclar, Liechtenstein) was used. 2 examiners evaluated marginal quality, proximal contact, discoloration, presence of 2^nd caries, loss of filling and hypersensitivity of restorations. The restorations was clinically evaluated by modified methods based on USPHS.

60 teeth were evaluated. 59 were clinically acceptable and 1 restoration which was placed in class v cavity in the posterior tooth was fallen out. In most cases, the restorations were clinically acceptable. For restorations which had been directly placed in the class II cavities, loose proximal contact was indicated as the main complaints.

Most of Anterior and posterior restorations which bad been directly or indirectly placed for 1 year were clinically acceptable. For posterior teeth, loose proximal contact was indicated as the main problem in the directly placed Class II restorations. Long term clinical study is needed.