01-09-2013 | Original Article
Chair-side generated posterior lithium disilicate crowns after 4 years
Published in: Clinical Oral Investigations | Issue 7/2013
Login to get accessAbstract
Objectives
The objective of this prospective clinical study was to evaluate the performance of chair-side generated crowns after 48 months.
Materials and methods
Forty-one posterior full contour crowns made of a machinable lithium disilicate ceramic (e.max CAD LT) were inserted in 34 patients applying a chair-side CAD/CAM technique. One crown per patient was randomly selected for evaluation at baseline, after 6, 12, 24, 36, and 48 months according to modified US Public Health Service criteria.
Results
After a mean observation time of 51 months (min, 48 months; max, 56 months; SD ± 2.3 months), 29 crowns were available for re-examination. Within the observation period, one failure occurred due to a crown fracture after 2.8 years. Four abutment teeth revealed signs of biological complications: Two abutment changed sensibility perception from positive to negative within the first 13 month. Two abutment teeth showed secondary caries below the crown margin, one after the 24, and another after the 48 month recall. Both abutments received cervical adhesive composite fillings. The failure-free rate was 96.3 % after 4 years according to Kaplan–Meier (CI: upper bound, 4.4 years; lower bound, 4.7 years).
Conclusions
Due to the fact that the secondary caries was not caused as a result of an inaccuracy of the crown margins and the endodontic complications were in a normal range, the clinical performance of the crowns was completely satisfying.
Clinical relevance
The chair-side application of lithium disilicate crowns can be recommended.