[Risk factors for class II dental restoration survival:a practice-based study]

The aim of this practice-based cohort study was to determine the performance and influence of possible variables in class II restorations related to practice, patient, tooth, and restoration. To do this, electronic patient files from 11 general practices in the Netherlands were collected, and 31,472 restorations placed between January 2015 and October 2017 were analysed. The observation time of restorations varied from 0 to 2.7 years, resulting in a mean annual failure rate (AFR) of 7.8% at 2 years. However, wide variation in AFRs existed among the operators, varying between 3.6% and 11.4%. An excess of patient-related variables, such as age, general health, periodontal status, caries risk and the presence of parafunctional habits and tooth or restoration-related factors, increases the risk of reintervention. Restorations placed due to fracture were more prone to fail than restorations placed due to caries. This study demonstrated that a wide variety of risk factors on the practice, patient, and tooth levels influences the survival of class II restorations.