A 3-year clinical evaluation of two composite resins in class-II cavities

The purpose of this investigation was to study the clinical performance of a new system with a proposed expanding liner for composite restorations introduced in the late 1980s. The present study reports on baseline data and the result after 3 years. One hundred and four class-II cavities in 95 patients were alternatively restored by Superlux Molar and the reference material P-50 APC by 12 general practitioners in 3 public dental health clinics. After 3 years 82 restorations (79%) were available for examination. The restorations were evaluated on the basis of USPHS criteria after 1 week and again after 3 years. Stone casts were used to quantitatively categorize wear in accordance with the Leinfelder method. Color slides and bitewings were taken to supplement the clinical evaluation of color match and marginal adaptation, respectively, and secondary caries. The failure rate (USPHS rating, Charlie) was four restorations of Superlux Molar and seven of P-50 APC. The average wear after 3 years of Superlux Molar was 131 microm and of P-50 APC, 128 microm. There were no statistically significant differences between the two materials with regard to, for example, handling characteristics, anatomic form, color match, marginal discoloration, or failures. A significantly higher wear rate was found after 3 years in patients with a high level of salivary lactobacilli (> 10(5) colony-forming units (CFU)/mL at base line) compared with those with lower levels. This suggests that an acidic environment might enhance the wear rate.