Clinical performance and marginal adaptation of class II direct and semidirect composite restorations over 3.5 years in vivo Roberto C. Spreafico a , Ivo Krejci b , Didier Dietschi b, * a Private office, Via Indipendenza 6, 21052 Busto Arzisio-Italy b Department of Cariology and Endodontology, School of Dentistry, University of Geneva, 19 Rue Barthe ´le ´my Menn, 1205 Geneva, Switzerland Received 17 October 2003; received in revised form 29 October 2004; accepted 2 November 2004 KEYWORDS Posterior composite; Class II restorations; Direct–semidirect techniques; Clinical trial; Marginal adaptation Summary Objective. The study evaluated the clinical performance and marginal adaptation of direct and semi-direct class II composite restorations in a split-mouth design over 3.5 years. Design. 44 upper posterior teeth in 11 adults with primary carious lesions were treated with 22 direct and 22 semi-direct restorations. Conventional cavities were prepared for both types of restorations. A fine fine hybrid composite (APH) and a multifunctional adhesive system (Prisma universal bond 3) were used for all restorations. The incremental ‘3-sited light curing’ technique was applied to direct restorations. Semi-direct inlays were prefabricated on silicone casts and post-cured using light and heat. Clinical performance was evaluated using modified USPHS parameters, while marginal adaptation was judged on replicas, using SEM and a standardized evaluation technique. Results. Clinical results after 3.5 years revealed a 100% retention rate with no fractures, sensitivity or recurrent caries for both types of restorations. SEM-evaluation of the occlusal margins showed at the tooth-restoration interface relatively low rates of marginal openings over the observation period (4–8%). Marginal restoration fractures ranged between 1 and 2%, marginal tooth fractures between 3 and 9%. Differences between the restorative techniques and after the different time observation periods were not statistically significant. Proportions of marginal fractures and openings at the restoration-luting composite interface were less than 10% after 3.5 years. Conclusion. The results indicated no significant differences for direct and semi-direct fine hybrid composite restorations in medium size cavities in posterior teeth with respect to clinical performance and marginal adaptation over 3.5 years. q 2005 Elsevier Ltd. All rights reserved. Journal of Dentistry (2005) 33, 499–507 www.intl.elsevierhealth.com/journals/jden 0300-5712/$ - see front matter q 2005 Elsevier Ltd. All rights reserved. doi:10.1016/j.jdent.2004.11.009 * Corresponding author. Address: Faculte de Medecine, Section de Medecine Dentaire, Universite de Geneve, 19 Rue Barthelemy Menn, 1205 Geneve, Switzerland. Tel: C41 22 382 91 65; fax: C41 22 781 12 97. E-mail address: didier.dietschi@medecine.unige.ch (D. Dietschi).