Expression Of SPARC And Type ? Collagen In The Periodontal Tissue Of Mice During The Teeth Extrusion

Objective:The purpose of the present study was to establish mouse models having un-opposed molars to study morphologic changes and examine the expression of SPARC and type ?collagen in the periodontal tissue of mice during the teeth extrusion,then knew about the mechanisms involved in teeth extrusion and laid the foundation of oral clinical repair work.Methods:There are 30 C57BL/6 mice were divided into two groups after removing the right upper molars,they were morphological observation group and Micro-CT group.Morphological observation group was divided into five subgroups,they were normal group(untreated group),three-day group,six-day group,nine-day group,twelve-day group after right upper molars extraction,five mice each group.Mandibles from morphological observation group were embedded after execution at pre-selected time points.Subsequently,samples were prepared for HE staining,Masson staining and immunohistochemical staining to observe the morphologic changes and examine the expression of SPARC and type ? collagen,then to discuss the relationship between them.Mice in the Micro-CT group were measured the relative levels of molar supereruption at different time point after teeth extraction.Results:The right mandibular molars extruded following the time after teeth extraction and the variation of it was significant.The results of HE staining showed that there were new bone depositing around periodontal tissue after right mandibular molars extruded.The results of Masson staining showed that the distribution of collagen fiber in periodontalmembrane was more tighter.The results of immunohistochemical staining showed that the expression of SPARC and type ? collagen was increased in periodontal tissue of right mandibular molars following the time after teeth extraction and the variation of it was significant(p < 0.05),the expression of SPARC and type ? collagen had positive correlation(r=0.951,p<0.05).Conclusion:During the period of 12 days after right upper molars extraction,The expression of SPARC and type ? collagen was increased following the right mandibular molars extrusion,they might play a role on teeth extrusion.