The Effect Of BFGF-collagen Composite Membrane On Direct Pulp Capping In Rats

ObjectiveThe bFGF-collagen membrane as the direct pulp capping agent was applied in theexposed pulp model in rats at the present study. The reaction of dental pulp andtertiary dentin bridge were observed.MethodsbFGF-collagen membrane was prepared, and its property was tested by SEM, andpH was detected. Eighteen male Sprague-Dawley rats were randomly divided into twogroups:9in Group Ca(OH)2and9in Group bFGF-collagen. Endodontic entry cavitywas prepared on the occlusion of the first molars in maxillary of each rat. The animalswere sacrificed at wks of2,4,8.The first molars in maxillary of each rat were fixed,decalcified and cut into slices. The sections were taken to hematoxylin-eosin staining(HE staining) and immunohistochemical staining of ALP, TGF-β1and COL-I. Thearea of tertiary dentin at wk of8was calculated by image analysis software. The dateswere analysed by SPSS13.0Levene’s test and t-test. P<0.05was consideredstatistically significant.Results(1) General observation results: At wks of2and4, both groups had no tertiary dentinformed; At wk of8, milky white tissue could be found in different sizes in bothgroups.(2) HE staining results: At wk of2, different degrees of inflammation under the cavitywere found in both groups. The inflammatory reaction in Group bFGF-collagen waslighter than Group Ca(OH)2. Functional stages of odontoblasts was observed in1casein Group bFGF-collagen; at wk of4, the formation of incomplete dentin bridge wereobserved in2cases in Group Ca(OH)2and4cases in Group bFGF-collagen. At wk of8, both groups had no obvious inflammatory reaction. Dentin bridge could be found inboth groups. Complete dentin bridge was observed in1case in Group bFGF-collagen.(3) Immunohistochemical results: The sections of2wk were stained with ALP,TGF-β1and COL-I immunohistochemical staining.1) ALP was located in the cytoplasm of cells. In Group Ca(OH)2, the surface of normal pulp was positive of ALP.In Group bFGF-collagen, the surface of normal dental pulp was strongly positive ofALP.2) TGF-β1was located in the cytoplasm of cells. In Group Ca(OH)2, the surfaceof normal pulp was positive of TGF-β1. In Group bFGF-collagen, the surface ofnormal dental pulp was strongly positive of TGF-β1.3) COL-I was located in theconnective tissue of pulp. In Group Ca(OH)2,the immunohistochemical stainingpositive expression of COL-I was uneven. In Group bFGF-collagen, theimmunohistochemical staining positive expression of COL-I was even.(4) Measure the area of tertiary dentin: The area of tertiary dentin in wk of8wascalculated by image analysis software. The dates were analysed by SPSS13.0t-test.The mean area of tertiary dentin of Group bFGF-collagen (1.82981mm2) was greaterthan Group Ca(OH)2(1.33591mm2). There was no significant difference betweenGroup Ca(OH)2and Group bFGF-collagen (P>0.05).Conclusion1、The bFGF-collagen composite membrane as direct pulp capping agent has noobvious irritation to pulp tissue.2、Compared with Ca(OH)2, bFGF-collagen composite membrane can promotepulp-dentin complex in the formation of dentin bridge much earlier and faster.3、The bFGF-collagen composite membrane can be used as an ideal agent indirect pulp capping.The bFGF-collagen composite membrane shows good physical and chemicalproperties, good mechanical properties and biocompatibility. As direct pulp cappingagent, it can promote the pulp-dentine complex in repairition and the formation oftertiary dentin. The bFGF-collagen composite membrane can be used as an ideal pulpcapping agent.