Clinical Evaluation of Composite-ceramic Implant-supported Posterior Crowns (Cerasmart)

The objectives of the present study are to analyze and to compare the survival rates and possible biological and technical complications arising from the use of composite-ceramic posterior implant-supported crowns with those obtained when using their counterparts prepared using monolithic zirconia restorations. The null hypothesis is that no differences would be found between the parameters studied for each type of restoration.

Eighty patients in need of posterior implant-supported crowns (n=80) were recruited from the Master of Buccofacial Prostheses and Occlusion, Faculty of Odontology, University Complutense of Madrid, Madrid, Spain. Before treatment, all participants were informed of the purpose of the study, the clinical procedures, the material to be used, and the advantages and risks of the restorations. They were asked to give their written informed consent to participate in the study. Eighty posterior implant-supported crowns were produced and allocated in parallel an randomly to either monolithic zirconia or composite-ceramic restorations by means of a randomization list. A total of 40 implant-supported crowns were placed using monolithic zirconia and 40 composite-ceramic. The clinical procedures were performed by two experienced clinicians. Full-arch impressions were taken using addition silicone. The restorations were cemented using a resin-based cement. The occlusion was adjusted and the surfaces polished after cementing. All restorations were prepared by an experienced technician. The restorations will be examined at one week (baseline), 1, 2, and 3 years by two researchers who were not involved in the restorative treatment. Each assessor evaluated the restoration independently, and the worst assessment will be used in the event of discrepancies.