Clinical Evaluation Of RelyX^TM Ultimate And Clearfil SAC On Bonding To Zirconium Oxide Ceramic Crowns

Objective: The aim of the study was to evaluate the clinical bonding efficiency of zirconium oxide ceramic crowns with RelyXTM Ultimate and Clearfil SAC resin cement.To compare the success rate of these two groups and provide some references for clinical application.Methods: Forty(40)teeth were selected and restored with zirconium oxide ceramic crown.The inclusion criteria of the selected teeth were as follows:(1)Complete root of all teeth;(2)Healthy periodontal conditions;(3)Good occlusion;(4)More than 5mm of occluso-gingival distance;(5)Normal pulpal vitality of the tooth;(6)Teeth with perfect root canal therapy;(7)Repaired with fiber post.The periodontal conditions were healthy and no obvious bone resorption by X-ray examination.The abutment of fixed bridge,immature permanent teeth,night bruxism and obvious inclined teeth were not included in the sample.40 cases were randomly divided into two groups.Zirconium oxide ceramic crown repair and cementing the zirconium oxide ceramic crowns with RelyXTM Ultimate or Clearfil SAC based on the principle of zirconium oxide ceramic crown preparation was carried out.Patients were followed up for 12 months.The evaluation criteria was in accordance with the standard criteria of the USPHS((US Public Health Service Criteria,USPHS)and was divided into three levels(A,B and C)depending on the evaluation results.Results: After checking the restoration retention,marginal adaptation,we learntthat 40 zirconium oxide ceramic crowns achieved level A after the try-in according to the evaluation criteria.12 months later,the follow up rate was 100%.After checking again,the result showed that there were 5 failure cases in C group: the margin of two crowns were not smooth,reaching level B;the color has changed on the edge of one crown,but can remove by polishing;periodontal condition of two cases were compromised,reaching level B;the other 15 cases all reached level A.In the R group,20 cases all reached level A.Conclusion: The application of RelyXTM Ultimate on cementing zirconium oxide ceramic crowns has achieved an excellent result,better than that of Clearfil SAC.