Longevity of composite restorations is definitely not only about materials

Objectives: This review study provides an overview of factors that influence the longevity of all types of direct resin composite restorations. Methods: A systematic search was performed in PubMed, Scopus, and Web of Science databases for articles reporting data from primary longitudinal clinical studies on composite longevity published 2011-2021. Prospective or retrospective studies with restorations in permanent dentition, with follow-up periods of at least 5 years were included. Results: In total, 33 articles were included with different study designs, practice settings, datasets, countries of origin, and sample sizes. Annual failure rates of restorations ranged from 0.08% to 6.3%. Survival rates varied between 23% and 97.7%, success rates varied between 43.4% and 98.7%. Secondary caries, fractures, and esthetic compromise were main reasons for failures. Risk factors for reduced restoration durability included patient-level factors (e.g., caries risk, parafunctional habits, number of check-ups per year, socioeconomic status), dentist factors (different operators, operator's experience), and tooth/ restoration factors (endodontic treatment, type of tooth, number of restored surfaces). Patient gender and the composite used generally did not influence durability. Significance: A number of risk factors are involved in the longevity of composite restorations. Differences between composites play a minor role in durability, assuming that materials and techniques are properly applied by dentists. Patient factors play a major role in