Effect Of Collagen Sponge On The Expression Of Gene During The Healing Process Of Alveolar Fossa After Tooth Extraction

Healing of dental extraction wound is a complex process involving the formation of blood clot,blood clot organization,granulation tissue formation,epithelium covering the extraction wound,and finally bone tissue formation.In this process,the maintenance of alveolar bone mass is very important for implant denture.At present,the methods reported in the literature to promote the healing of tooth extraction wound are difficult to be widely used in clinical practice because of the complicated operation methods,high cost,psychological rejection and other factors.Therefore,it is extremely urgent to explore a simple method which can effectively reduce bone resorption and shorten the waiting time for tooth repair.Collagen sponge has good biocompatibility,strong hemostatic effect and adsorption function.It is easy to deposit calcium ion and phosphate ion locally.It can provide enough space for blood clot agglutination in bone cavity after tooth extraction and promote osteogenesis effectively.At present,collagen sponge is widely used to fill the bone cavity and the buried tooth cavity after the operation of jaw cyst,which showed wonderful hemostatic effect,and the speed of bone formation in the cavity improved significantly.Experimental studies on collagen sponges promoting healing of alveolar socket have been reported successively,but there is a lack of gene level studies.The aim of this study was to investigate the effect of collagen sponge on the expression of osteogenesis-related genes in alveolar fossa tissues,and to provide a preliminary reference for exploring the mechanism of collagen sponge promoting osteogenesis.Objective:To explore the expression of gene during early bone healing of alveolar fossa after tooth extraction.Methods:1.Establishment of tooth extraction model:SD rats were anesthetized with 10%chloral hydrate and fixed in supine position on the operating table.The first molar gingival of the right maxillary was separated after Iodophor disinfection in the operating area.The teeth were extracted.The Collagen sponge was placed in the alveolar fossa.The left side was the control side.Observe the breathing of rats to avoid suffocation.Mice recovered well after operation.Four mice were sacrificed at 1,2,4 and 8 weeks after tooth extraction.The alveolar bone and granulation tissue of the dental socket of the mice were taken for gene detection.2.Detection of osteogenesis-related gene expression by real-time quantitative PCR:According to the kit operation procedure,RNA was extracted from the samples.The cDNA was obtained after reverse transcription,and stored in refrigerator at-20 ?.Then the expression of gene was measured by real-time quantitative PCR.The difference of gene expression between the experimental group and the control group was calculated by 2-??CT method.Results:1.At 1,2,4 and 8 weeks after surgery,expression of gene in alveolar fossa tissue of the experimental group was significantly higher than that of the control group(P<0.05).2.In the experirmental group,The expression peak of ALP gene appeared at second weeks after operation.The expression peak of other genes(Osterix gene,Runx2 gene or Vegf gene)appeared at forth week after operation.Conclusions:1.ALP gene,Osterix gene,Runx2 gene and Vegf gene were expressed in both experimental and control side tissues.Collagen sponge could upregulate the expression of these genes.2.The expression of ALP gene,Osterix gene,Runx2 gene and Vegf gene increased at first weeks and then decreased.