Effect Of The Position Of The Cervical Margin Of Porcelain Fused To Metal Crown On Periodontal Tissue

[Objective (s)] By detecting different neck edge location of the porcelain fused with metal (PFM) crowns gingival crevicular fluid volume and composition before and after repair, and combining the clinical test indicators, analysis testing index changes, to investigate the PFM crowns cervical margin position effects on periodontal tissue.[Methods] Sixty patients who needed PFM crown for the mandibular fist molar were randomly divided into groups of 30 patients each according to the neck edge position of PFM crown design divided into group A (0.5 mm) under crown in gingiva and group B (crown level gum). Testing before crown repair, repair after 1 month,3 months,6 months gingival crevicular fluid (GCF) quantity of aspartic aminotransaminase (AST) and alkaline phosphatase (ALP), gingival index (GI) and alkaline phosphatase (ALP) and clinical index of gingival index (GI) and gingival crevicular exploration of probing depth (GCD) changes.[Results] 1. Group A (crown margin in subgingival 0.5mm):amount of gingival crevicular fluid, ALP and AST content and the clinical indexes of GCD and GI scores, in crown repair,1 month,3 months,6 months increased significantly, the difference is statistically significant (P< 0.05);2.Group B (crown and neck margin flat gum):there was no significant difference (P>0.05) 3. between the two groups at the same time point of the difference was statistically significant (>0.05 P)[Conclusion(s)] Based on the results of this study,the PFM crown with gingival margin at gingival level is better than that under gingival leve lin terms of its benefit to periodontal health.