Overview
The objectives of the present prospective randomized clinical study are to evaluate and to compare the survival and success rates, possible biological and technical complications, and the clinical performance of metal-ceramic, monolithic zirconia and resin-matrix posterior crowns.
The null hypothesis is that no differences would be found between the parameters studied for each type of restoration.
Description
A total of 60 patients, in whom the placement of a crown in the posterior region of the maxilla or mandible was indicated, will be included in the study. The patients will be recruited from the Master of Buccofacial Prostheses and Occlusion (School of Dentistry; University Complutense of Madrid). Prior to treatment, patients will be informed regarding the aims of the study, the clinical procedure, the materials used, the risks and benefits of ceramic restorations and the alternatives to the proposed treatment. All the patients will be provided with a written informed consent for the inclusion in this study, Ninety posterior crowns will be produced and assigned in parallel and randomly to either resin-matrix ceramic, zirconia or metal-ceramic restorations. Three experienced prosthodontists will treat the patients. Abutment preparation will be performed in a standardized manner: circumferentially chamfer (1 mm in width), axial reduction of 1 mm, and an occlusal reduction of 1.5 to 2 mm. The tapering angle between the axial walls will be approximately 10- to 12- degrees. Full-arch digital impressions will be taken using an Intraoral Scanner. The restorations will be cemented with a resin cement. 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
Eligibility
Inclusion Criteria:
- One posterior tooth (molar or premolar) to be crowned,
- Vital abutments or abutments with sufficient endodontic treatment
- Abutment not crowned previously
- Periodontally healthy abutments with no signs of bone resorption or periapical disease --
- Adequate occlusogingival height
- Stable occlusion, and the presence of natural dentition in the antagonist arch.
Exclusion Criteria:
- Patients who present reduced crown length (less than 3 mm occlusogingival height
- Poor oral hygiene, high caries activity, active periodontal disease or bruxism.