Study On The Effect Of The CAD/CAM Zirconia All-ceramic Crowns Restoration On Periodontal Tissue’s Health

Objective:The paper is focusing on investigating the effect of CAD/CAM zirconia all-ceramic crowns restoration on the state of periodontal health. It makes an investigation on risky factors influencing of periodontal health by CAD/CAM zirconia all-ceramic crowns restoration. And it also provides scientific method and basis for maintaining the periodontal health of the abutment teeth for patients of CAD/CAM zirconia all-ceramic crowns restoration.Testing Subjects and Methods:Firstly, choose 64 abutments of 55 patients randomly to give full crown restoration. The experimental group is the 32 abutments of 29 patients which would be restored by CAD/CAM zirconia all-ceramic crowns. The controlled group is the 32 abutments of 26 patients which would be restored by Ni-Cr alloy PFM. The volume of GCF, the level of IL-6 and TNF-α of the 64 patients are examined at the pre-restoration and post-restoration stages. Meanwhile, the examination of 64 patients periodontal clinical indicators, which include gingival sulcus bleeding index(SBI), probingdepth(PD), plaque index(PLI) and attachment loss(AL) are recorded. Secondly, analyze the main risky factors of periodontal tissue’s health by CAD/CAM zirconia all-ceramic crowns restoration by using the method of questionnaire investigation, and record periodontal clinical indicators examination of 190 abutments of 146 patient.Results:1.The experimental group(the group of zirconia all-ceramic crowns restoration)conparison study between the pre-restoration and post-restoration stages: The volume of GCF, the level of l L-6 and TNF-α compared have no significant differences(P>0.05. SBI, PD, PLI and AL have no significant differences(P>0.05).2.The controlled group(the group of Ni-Cr alloy PFM restoration) conparison study between the pre-restoration and post-restoration stages: The volume of GCF, the level of l L-6 and TNF-α have significant differences(P<0.05). SBI, PD and PLI have significant differences(P<0.05). AL has no significant differences(P>0.05).3.The comparison between the experimental group and the controlled group after restoration:The volume of GCF, the level of l L-6 and TNF-α have significant differences(P<0.05). SBI, PD and PLI have significant differences(P<0.05). AL has no significant differences(P>0.05).4.Through analyzing the examination of periodontal clinical indicators of 190 abutments by CAD/CAM zirconia all-ceramic crowns restoration, PD, AL, SBI, gingival edge dyeing and restoration marginal recurrent caries between the pre-restoration and post-restoration stages have no significant differences( P > 0.05). PLI between the pre-restoration and post-restoration stages have significant differences(P<0.05). Through analyzing the main risky factors of PLI of abutments by CAD/CAM zirconia all-ceramic crowns restoration, the conclusion is drawn that the patients’ s age, smoking habit, habit of brushing teeth, the habit of dental flossing, mental pressure and the periodontal treatmen in 3 months before the return visit have significant differences(P<0.05).Conclusion:1. Compared between the pre-restoration and post-restoration stages in 12 months of the group of CAD/CAM zirconia all-ceramic crowns restoration(P>0.05), there is no inflammatory change in periodontal tissues.2.Comparedbetween the pre-restoration and post-restoration in 12 months of the group of Ni-Cr alloy PFM restoration(P<0.05), there are inflammatory changes in periodontal tissues.3.Compared the group of Ni-Cr alloy PFM restoration with the group of CAD/CAM zirconia all-ceramic crowns restoration(P<0.05). According to the result of the experiment,we recommendedus using CAD/CAM zirconia all-ceramic crowns to restoration tooth.4. According to the study, the patients’ s age, smoking habit, the habit of brushing teeth, the habit of dental flossing, mental pressure and the periodontal treatmen in 3 months before the return visit may be the main risky factors of the periodontal tissue’s health.