Study On Resistance Of Different Kinds Of Post - Core Repairing Thin - Walled Root Canals

Objective:Three different materials repairing the flexural strength and fractured tooth form were used for thin wall tubes after root canal treatment by in vitro resistance test, compared the strength of three kinds of pile nuclear and root canal treatment after the influence of tooth bending performance, providing scientific basis for clinical application.Methods:within 60 months of the removal of similar form and complete mandibular first premolars, root length≥13.0 mm, root canal therapy were randomly divided into six groups concluding dentin shoulder collar height and the kinds of pile nuclear for two factor, each group of 10. Each group first reoccupied after cyclic loading fatigue experiments on universal material testing machine to test its fracture strength. Loading point was located in the teeth cut one-third of lingual, loading direction and tooth long axis 135° angle, loading speed of 1.0mm/min, continuous sample loading until fracture occurs, recording fracture type instantaneous force value and experimental specimen tooth damage occurs.Results:(1) Test results of destructive mechanical tests for CAD/CAM integration of the quartz fiber post nuclear and gold alloy casting pile nuclear repair group, there was no statistically significant difference (p> 0.05);But above into quartz fiber post and resin core group, the difference was statistically significant (p<0.05). (2) Test results of Herschel exact probability analysis method, different materials of pile nuclear fix fracture type distribution differences had no statistical significance (P> 0.05);Different dentin shoulder collar height of tooth root tube wall fracture type distribution difference between groups was statistically significant (P<0.05).Conclusion:(1)CAD/CAM quartz fiber post and gold alloy casting pile repair big taper tube might be able to obtain a better clinical effect and have high bending strength. (2) Different materials of pile nuclear repair fracture type distribution among each tooth are the same; Dentin shoulder collar is 2 mm and 0 mm on the fracture types distribution.