Ceramics with framework of zirconium oxide have high fracture strength and high survival rates clinically .
We did a systematic review of strategies and methods describing the treatment of teeth with onlay or crown and the subsequent clinical of failure of these restorations.
Our research group, Clinicians Report or CR Foundation, has confirmed both types of data.
Your question concerning which is the best type of crown is commonly asked.
It has been reported that onlays and overlays have been proposed for restoring root filled teeth .While a porcelain-fused-to-metal crown can serve as a strong and esthetic restoration, patients too often receive this type of restorations for minor irregularities that could have been better handled by conservative treatment .It has been reported that distortion related to margin design in porcelain-fused-to-metal restoration creates a space for accumulation of bacterial plaque which could lead to gingival inflammation.Principal reasons for failure were secondary caries fractures, marginal deficiencies, wear and postoperative sensitivity.Minimally invasive dentistry, in cases in which it is appropriate, is a concept that preserves dentition, supports structures and involves low cost therapy.