Clinical evaluation of the functional criterions for ceramic crowns made from zirconia reinforced lithium silicate

Abstract

Background & Aim: ceramic crowns have become a very common cosmetic choice due to their highly aesthetic properties in addition to their long-term clinical survival, and considering the various methods of manufacturing ceramic crowns it has left the practitioner facing a difficulty when it comes to choosing the best technique there is for manufacturing ceramic crown, thus the aim of this study is to evaluate the functional criterions of the crowns that are fabricated  from zirconia , IPS emax press and zirconia reinforced lithium silicate(ZLS).

Materials and Methods: The research sample consisted of (60) crowns (N=60) that have been done on 13 patients and it was divided into three equal groups (n1=n2=n3=20). In the first group, ceramic crowns were fabricated from ZLS, in the second group, ceramic crowns were fabricated from (IPS e.max Press) and in the third group, crowns were fabricated from zirconia. The functional criterions of crowns were evaluated according to the World Dental federation (FDI) (fractures or cracks – marginal adaptation – proximal anatomical form – patient satisfaction of the aesthetical and functional properties) after one week- 3 – 6 – 12 months of the cementation. data analysis was done using Mann-Whitney U test and using Friedman test for correlated samples for studying the significance of statistical differences at significance level (0.05=α).

Results: the results of evaluating the functional criterions of  crowns were clinically accepted, whereas there were no statistically significance differences in all of the functional evaluation criterions and in all of the follow-up periods, except for the marginal adaptation criterion, the marginal gap in the ceramic crowns made from IPS emax press was lower than the crowns made from zirconia and the ceramic crowns made from zirconia reinforced lithium silicate(ZLS) with a statistically significance difference after 3, 6 and 12 months of Follow-up.

Conclusions: in the limits of this study we conclude that ceramic crowns made from IPS emax press had a lower marginal gap than crowns made from zirconia and (ZLS), Moreover no differences were detected in the clinical functional evaluated criterions between the three types of crowns  (fractures and cracks, proximal anatomical form, patient satisfaction).