Comparative Clinical Examination Regarding Soft-Tissue Development Related to Zirconia Restaurations

Objectives: It was the aim of this clinical examination to analyze middle-term results of clinically available full ceramic zirconia (ZrO2) abutments and cemented crown caps (Procera AllZirkon) in the side tooth area, which were screw-fixed on Brånemark implants. These shall be compared with approved aluminium oxide crown systems (Procera AllCeram crowns) in the context of a human prospective study. Methods: 20 patients were included consecutively in the study, each with one Procera abutment and crown (n = 10 ZrO2, n = 10 AL2O3) by randomisation. All patients were examined in the context of a special clinical and radiological follow-up two weeks and six months after insertion of abutments and veneered crown caps. Possible changes of the peri-implant soft (measured by the papilla index according to Jemt) and hard tissue (radiologically) were evaluated. Another topic was the evaluation of the subjective aesthetic overall impression of patient and therapist using a visual analogous scale – (VAS). Results: Concerning the radiological and periodontal parameters, good tissue compatibility was observed for both materials analyzed after two weeks and after six months. The analysis of the resulting soft tissue situation according to the papilla index to Jemt tended to reveal a more favourable development in the group with zirconia restorations. The subjective assessment of patient and dentist opinion concerning colour, form, emergence profile and aesthetics of the inserted abutment-crown combination showed a very good result for the two materials investigated. Conclusion: Due to advantages in material property zirconia abutments and crown caps might be the preferable choice, but the clinical results of this study were comparable for both materials analyzed. Acknowledgment: We appreciate Nobel Biocare allocating the abutments and caps.