Experimental Research On Expression Of Bone Morphogenetic Protein-2 In The Ectopic Osteogenesis Progress Of Decalcificated Dentin Datrix

Objective:Though ectopic osteogenesis exprimental research and Immunohistochemical technique, to observe and evaluate bone morphogenetic protein-2 in decalcifica-ted dentin matrix.Method:24 2-2.5KG New zealand white rabbits randomly divided into 8 groups, each group of 3。Feeding with a standard rabbit diet, water is no restricted.To make 4 muscle bags on the erector spinae in each rabbit. On one side filled with manufactured decalcificated dentin matrix,on the other side filled with self-made decalcificated dentin matrix and a few sutures as the control group. The rabbits were sacrificed after 1,2,3,4,6,8,12,16 weeks and the samples examined by immunohistochemical staining to indentificate the BMP-2. The brown staining cell is the positive cell with BMP-2 inside.The Staining intensity is judged by the rule below.No brown for 0 point;Light brown for 1 point;brown for 2 point and nigger-brown for 3 point. The percentage of positive cells was count the positive cells from 100 cells in 400 times view,which accounted for the proportion of positive cells, taking the average of 5 views.The results was semi quantitative analysised:the positive express rate is multiplyed by the staining intensity and the percentage of positive cells.All the datas were analysised by SPSS17.0 statistical software.Results:1 General observationAll 24 rabbits survived.Two hours after surgery, no wound was exudated,the Suture was fixed. After 1 day,the rabitts’ diet、action and defecation were normal,no DDM was excreted.After 2 weeks,the suture on the wound continue to fall off, the wound healed gradually. After 16 weeks,the wound was completely coverd by new hair. the rabitts’ diet、action were normal.2 Immunohistochemical stainingIn the manufactured group, BMP-2 cells appears at 1 weeks,with light brown staining and small staining area.In 2 weeks, the staining area and intensity increased slightly.In 3、4 weeks,the staining intensity turn to brown or dark brown.The staining area in 4 weeks reachd the maximum level.In 6、8 weeks,the staining turn to be brown or light brown,the staining area decreased.In 12 weeks the staining turn to be brown or light brown,the staining area continuly decreased.The staining intensity and area in 16 weeks were the minimum.The brown stained area appeard around the DDM at the first week,and then gradually went away from DDM.In the self-made group, BMP-2 cells appears at 1 weeks,with light brown staining. The brown stained area appeard around the DDM..In 2 weeks, the staining area increased slightly,the color turned to be light brown. The brown stained area gradually went away from DDM. In 3、4 weeks,the staining intensity and size reachd the maximum level. The brown stained area appeard far away from DDM. In 6、8、12、16 weeks,the staining area and indensity decreased.In the control group,there was no Persuasive brown staining area appear.On the contrary, hematoxylin staining of the muscle cells appeard.Over time,there was no obvious change. In 6、8、12、16 weeks,the blue staining muscle cells appeared.3.The results of statistical software SPSS.The product group and self-made group showed positive expression of BMP-2 in the first weeks. The expression intensity of each week were different. From 1 to 4 weeks, the staining area increased slightly,then he staining area and indensity decreased from 6 to 16weeks. Between each time point, the difference was statistically significant(P<0.05).The arithmetic product of the manufactured group is:0.0289±0.0088.0.0427±0.0050.0.0709±0.0102、0.1136±0.0146、 0.0380±0.0063、0.0125±0.0012、0.0035±0.0016、0.0029±0.0007; the arithmetic product of the self-made group is:0.0231±0.0142、0.0237±0.0020、 0.0518±0.0042、0.0599±0.0086、0.0272±0.0051、0.0053 ±0.0006、0.0027 ±0.0005、0.0055±0.0033; the arithmetic product of the control group is:0.0009 ±0.0014、0.0002±0.0002、0.0004±0.0003.0.0006±0.0004、0.0003±0.0002、 0.0006±0.0003、0.0003±0.0002、0.0001±0.0002。The control group showed negative expression rate on each week. There was no significant difference between each week. The positive expression in the product group was significantly higher than the self-made group.The control group was the minimum. There were statistically significant differences between the 3 groups(P<0.05).Conclusions:1. After DDM had been implanted in the rabbit erector spinae bags, there has no Immunological rejection and tissue inflammation in the observative period.Which demonstates that DDM has well histocompatibility.2. The product group and self-made group detected the positive cell in each week,and the positive express rate was significantly higher compared with controls. When DDM was imlanted,it can increase the content of BMP-2 locally.3.The positive expression in the product group was significantly higher than the self-made group, the difference was statistically significant(P<0.05).