Purpose: The objectives of this two-period, crossover, mono-centred, double-blind, randomised controlled trial (RCT) were to compare two different materials used for full arch implant-supported prosthetic restorations with regard to patient preference and impact on a patient's quality of life. Materials and methods: Edentulous patients requesting one full arch restoration in the mandible or maxilla supported by dental implants were included in this study. Patients were randomised to receive either a full arch zirconia framework hand-veneered with ceramic, or a full arch zirconia framework hand-veneered with composite material. After 1 month, the first randomised restoration was substituted by the other, which was left in function for a further observation period of 1 month. Outcome measures were: patient preference and satisfaction (OHIP-21), complications, visual analogue scales for chewing comfort, aesthetic acceptance, phonetic comfort, full mouth plaque score (FMPS). Results: Twenty-four patients were randomised to the treatments in the two periods. There was one dropout. At the end of the study, 16 patients (70%) preferred to wear ceramic prosthesis and 7 patients (30%) preferred to wear composite prosthesis (ceramic preference: 70%; 95%CI from 47 to 87%; P = 0.0605). Difference in OHIP-21 reduction between the two treatments was not significant (difference 0.5, 95%CI from -2.8 to 3.8, P = 0.7788). There was one minor complication during the ceramic period in one patient and one minor complication during the composite period in another patient (odds ratio 1.00, 95%CI from 0.06 to 15.99, P = 1.0). The difference in FMPS between treatments was not significant (0.5, 95%CI from -1.3 to 2.2, P = 0.5731). Difference in VAS between the two treatments was not significant for general satisfaction (P = 0.2067), chewing comfort (P = 0.8345) and phonetics (P = 0.9167). Difference in VAS between the two treatments was significant for aesthetic acceptance favouring the ceramic prosthesis (difference 0.9, 95%CI from 0.006 to 1.8, P = 0.0486). Conclusions: No difference between the two treatments was detected for preference, changes of OHIP-21, complications, reduction of FMPS, VAS changes regarding patient satisfaction, chewing and phonetics. Nevertheless, a slight difference was detected in the VAS regarding aesthetic acceptance favouring the ceramic material. Funding: The study was supported by Nobel Biocare (grant 2012-1077). Thanks to this contribution, the patients who consented to participate in this RCT were not charged for the material provided by Nobel Biocare. In addition, the patients benefited from a further back-up prosthesis that was provided to them completely free of charge.
Keywords: ceramics, composite resins, cross-over studies, dental implant, patient preference, patient satisfaction
Conflict of interest statement: This is an author-driven study. The supporting company had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript. The authors prepared the protocol of this study and the supporting company was permitted to review the manuscript and suggest changes, however, the authors exclusively retained the final decision on content.
