生物陶瓷封闭剂nRoot和生物陶瓷牙胶尖的根尖封闭性研究OACSTPCD

Objective To evaluate in vitro the apical sealing property of nRoot,a new domestic bioceramic root canal sealing agent,and the apical sealing property of bioceramic tooth adhesive tip when applying bioceramic root canal sealing agent,providing a theoretical basis for clinical material selection.Methods Single-canal premolars were randomly divided into four experimental groups and two control groups.The crowns were removed from the cemento-enamel junction.The root canal was prepared by gradual deepening technique,and then the root canal was obturated by using bioceramic sealant modified hot gutta-percha vertical compression filling technique recommended by Martin Trope.Group A:nRoot root sealer combined with bioceramical tooth tip.Group B:nRoot root canal sealer combined with common gum tip.Group C:iRoot SP root canal sealer combined with bioceramical tooth tip.Group D:iRoot SP root canal sealer combined with common gum tip.Group E and group F were positive control group and negative control group respectively.The apical closure of each group was observed by dye permeation method and scanning electron microscope.The longer the dye permeation length was,the wider the microgap was,the worse the apical closure was.Results Dye penetration test results show that,group A(2.455±0.137)mm,group B(2.830±0.148)mm,group C(2.426±0.130)mm,group D(2.774±0.163)mm.There was no significant difference between iRoot SP and nRoot(P＞0.05).There was a significant difference between bioceramics and common dental gums(P＜0.05),and the average value of dye Penetration of bioceramics dental gums was lower than that of common dental gums.There was no significant interaction between root canal sealant and gum tip(P＞0.05).Scanning electron microscopy results showed that micro-gaps of varying sizes were visible at the interface between filling materials and dental tissue in all groups.groups B and D with common gutta tips showed larger micro-gaps,while groups A and C with bioceramic gutta tiPs showed smaller micro-gaps.There was no significant difference in microgap width between group B and group D,and between group A and group C.Conclusion ①nRoot,a new bioceramics root canal sealer,has similar aPical closure as iRoot SP.②When using bioceramic root canal sealer,the aPical closure of bioceramic gutta-percha tips is better than that of common gutta-percha tips.③The effects of root canal sealant and gutta-percha tip on the apical closure were independent and did not interfere with each other.