Influence of II type collagenase level in gingival crevicular fluid on the two different marginal shapes of all ceramic crown of anterior teeth

Objective To investigate the changes of the level of Ⅱ type collegenase(COLⅡ) in gingival crevicular fluid(GCF) before and after restoration with two kinds of all-ceramic crown shouldered design.Methods The patients who received all ceramic crowns were divided randomly into 90° shoulder margin group and chamfer margin group,and each group with 20 teeth.The COL-Ⅱ level in GCF were analyzed before tooth preparation,one month,three months,six months and twelve months after all ceramic crown placement.The COL-Ⅱ level in GCF was detected by using ELISA method.Results According to 3 months after the crown restoration,the COL-Ⅱ level in GCF of 90° shoulder margin group was obviously higher than that of chamfer margin group,showing a statistic significance(P 0.05).As to 6,12months after the crown restoration of two groups,the COL-Ⅱ level was different to that of two groups either before tooth reparation or 1,3 months after all ceramic crown cementation,showing a statistic significance also(P 0.01).Two groups had no significant difference in the COL-Ⅱ level between 6,12 months after restoration and before tooth reparation.Conclusion The chamfer margin of all ceramic crown can be recommended use in clinic.The periodontal tissue can be recovered over six months after restoration.