Experimental Study Of High Fluidity Bioceramic Materials In Pulp Revascularization Of Rat

Objectives After the establishment of the rat model of periapical periodontitis,the three materials of Ca（OH）₂,MTA and i Root BP were used to establish the model of maxillary first molar pulp revascularization,respectively,and compared with Micro-CT imaging.And quantitatively study the expression results of basic fibroblast growth factor（b FGF）,platelet-derived growth factor（PDGF）,vascular endothelial growth factor（VEGF）and tumor necrosis factor（TNF-α）in the process of dental pulp revascularization,and explore The different mechanisms of action of i Root BP,Ca（OH）₂,and MTA provide a theoretical basis for the application of highly fluid bioceramic materials in the treatment of pulp revascularization.Methods This experiment is divided into two parts:the first part:imaging study of periapical periodontitis and revascularization of young permanent teeth in SD rats;36maxillary first molars of 18 3-week-old SD rats were randomly selected,of which 28 were established The model of periapical periodontitis is divided into 4 weeks old apical periodontitis group A1（4 capsules）,8 weeks old revascularization group A2（12 capsules）,17 weeks old revascularization group A3（12 capsules）,among which The group is divided into A2Ca（OH）2 group,A2MTA group,A2i Root BP group,A3 group is specifically divided into A3Ca（OH）2 group,A3MTA group,A3i Root BP group,each group 4;the other 8 are not treated,divided It is 4 weeks old control group A4（4 tablets）,17 weeks old control group A5（4 tablets）.28 SD rat maxillary first molars were established by endotoxin smear+open method.The periapical periodontitis model was established.The A1 and A4 groups were sacrificed after 1 week of model establishment（4 weeks old）and were sacrificed.Micro-CT detection;A2 and A3 groups were sterilized and blooded on the basis of periapical periodontitis（4 weeks old）,and Ca（OH）₂,MTA,and i Root BP were used to establish dental pulp revascularization models.After 4 weeks of revascularization,rats in group A2（8 weeks old）were sacrificed for Micro-CT scan;after 13 weeks of revascularization,rats in groups A3 and A5（17 weeks old）were sacrificed for Micro-CT scan;Part II:Expression of periapical periodontitis and revascularization factors of young permanent teeth in SD rats.A total of 48 SD maxillary first molars were randomly selected from 24 rats,of which 32 were established to be a model of periapical periodontitis,and were divided into a 4-week-old periapical periodontitis group B1（8）and an 8-week-old revascularization group B2 24),of which B2 group is specifically divided into B2Ca（OH）₂group,B2MTA group,and B2i Root BP group,8 in each group.The other 16 tablets were not treated as the 4-week-old control group B3（8 tablets）and the 8-week-old control group B4（8 tablets）.Groups B1 and B3 were sacrificed 1 week after the establishment of the periapical model（4 weeks old）and obtained maxillary specimens.Each group was randomly selected 4 histological sections for HE staining,immunohistochemical detection of b FGF and PDGF For expression,another 4 were tested with Real Time-PCR to detect the expression of VEGF and TNF-α;group B2 established blood circulation using Ca（OH）₂,MTA,i Root BP 1 week after the establishment of periapical model To reconstruct the model,rats in the B2 and B4 groups（8 weeks old）were sacrificed 4 weeks after revascularization,and b FGF,PDGF,VEGF,and TNF-αwere detected.Finally,the grouping results are statistically analyzed.Results 1 Imaging examination:1 week after apical periodontitis treatment,the apical low-density shadow was larger than that of the control group;at 4 weeks after revascularization intervention,the apical low-density shadow disappeared and the tooth root continued to develop;at 13 weeks after the intervention The medullary cavity narrowed,the root canal wall thickened,and the apical foramen formed.The i Root BP group was the most obvious.The expression of factor 2:（1）HE staining results:B1periapical epithelium hyperplasia enters the apical foramen,and connective tissue and inflammatory cells can be seen;there are new blood vessel endothelial growth in the lumen of each group of B2,and new bone-like in the apical area Tissue;immunohistochemical results:the expression of PDGF and b FGF in B2 was higher than that in control group B4（P<0.05）,i Root BP group was superior to Ca（OH）₂and MTA group.（2）Real-Time PCR results:the expression of VEGF in B2 was higher than that in control group B4（P<0.05）,and the expression of VEGF in i Root BP group was the highest;the expression of TNF-αin B1 was higher than that in B3（P<0.05）,B2 The group was lower than the B1 and B4groups（P<0.05）.Conclusions 1 The experiment successfully established a model of periapical periodontitis and revascularization of young permanent teeth of the rat maxillary first molar;i Root BP can better promote tissue healing and blood vessels than MTA and Ca（OH）₂in pulp revascularization Generation,The highly mobile bioceramic material i Root BP has a good handling feel and can be used as an excellent sealing material in the treatment of pulp revascularization.Figure:9;Table4;References:119...