2 Year Follow-up of Indirect Resin Composite Restorations Luted With Different Adhesive Resin Cement: A Randomized Clinical Trial

Study design The ethical committee of Istanbul Medipol University approved this clinical study. Patients were given written informed consent to participate before treatment and agreed to a recall program at baseline 2 weeks, 6 months, and thereafter annually. All restorative procedures were carried out by one experienced dentist from the Department of Restorative Dentistry at Istanbul Medipol University.

Inclusion and exclusion criteria

Patients in need of removal of old large amalgam restorations or having extensive caries lesions were recruited for the study. Inclusion and exclusion criteria were as follows:

Adults of at least 18 years of age, with good oral hygiene, having an antagonist tooth in occlusion, being mentally in a good state to provide written consent to participate in the clinical study, and willing to attend the scheduled follow-up appointments. Exclusion criteria included the presence of teeth with severe periodontal problems, high caries risk, and bruxism.

Cavities were prepared according to common principles, which included an occlusal reduction of 1.5-2 mm with a wide isthmus and rounded occlusal-axial angles, and an axial wall of 1.5 mm in thickness. Where possible, the gingival margins were prepared entirely in enamel at the cemento-enamel junction, and cavities for overlays included both buccal and lingual/palatal cusps. Both cavity types (onlays and overlays) were prepared with rounded internal angles, with a divergence of 6-15° between the walls and margins with a 90° cave surface.