A five-year clinical evaluation of Class II composite resin restorations

Objectives: To study the clinical efficacy of posterior composite resin res torations placed in general practice after five years. Methods: Two commercial composite resin systems were used. Three general pr actitioners placed the restorations at a Public Dental Health Service Offic e. The patients were not selected specifically for this study. Class II cav ities were restored with Superlux Molar and P-50 APC composite systems on a n alternate basis. At baseline, 63 restorations were placed in molars and p remolars in 45 patients. For primary caries, generally a conservative cavit y design was used (n = 23), while replacements of amalgams resulted in the larger conventional Class II design (n = 40). The restorations were assesse d using a modified USPHS criteria. Wear measurements were determined by the Leinfelder method. Photographs and bite-wing radiographs were taken to sup plement the clinical evaluation of colour match, marginal adaptation and re current caries. Saliva sampling was performed to determine the rate of secr etion and the level of mutans streptococci and lactobacilli. Results: Ar the five-year review 51 restorations were available for examina tion, of which nine restorations were rated clinically unacceptable. Includ ing the failed restorations (n = 7), at the three-year review, a total of 1 6 restorations had failed (27.6%) over a five-year period. The most common reasons for failure were recurrent caries (n = 7) and marginal defects (n = 4). The mean wear of Superlux Molar was 167 mu m and of P-50 APC 158 mu m. Fight of the 11 patients with failed restorations due to caries and margin al defects had high counts of mutans streptococci at baseline. Conclusions: The failures in the present group of patients did not specific ally relate to material, tooth type or cavity design. However, it is sugges ted that patient factors such as caries activity should be monitored and ma naged. (C) 2000 Elsevier Science Ltd. All rights reserved.