| Fiber posts were widely used in clinic,because of excellent physical and chemical properties.It could protect teeth for high mechanical strength, especinlly similar elastic modulus with dentin.Now the research was focused on the adhesive materials because the failure of post system and adhesion were the main reason of restoration failures.Nowadays,there were many researches about adhesive and core materials to the fiber posts but not conclusive.A kind of general material which was used for fiber post bonding and core forming was put on to the market and was very convenient to clinic operation.So far,there were no reports about it in the country and we made a research about such kind of a trial resin material.The objection of this research was to value bonding strength and biocompatibility of this trial material.There were three groups in the experiment which were A:the trial resin material.B:Clearfil DC Core(Kuraray,Japan),C:Luxa Core-Dual(DMG, Germany).We compared the bonding strength of these three kinds of material with root canal dentin by the way of micro push-out,then observed the two bonding surfaces between fiber post and cement or between cement and dentin. And then,the strength of anti-fracture in non-vital teeth was compared after post cementation and core forming.At last,biological safety of this trial resin was valued by way of acute general toxicity test,oral mucous membrane irritation test and cytotoxicity test.The results were followed:1 The bonding strength of three kind of cement in upper,middle and apical 1/3 of the root were sperately:A 12.58±3.64 MPa,8.23±4.15 MPa,6.82±1.96 MPa,B 14.64±3.47 MPa,9.27±3.71 MPa,7.67±2.33 MPa,C 11.85±2.83 MPa,6.21±3.42 MPa,5.38±2.14 MPa.The statistical analysis showed that there were no significant difference between bonding strength of group A and B in the upper 1/3 of the root,which were both lower than that of group C; either between group A and B in the both middle and optical 1/3,which were higher than that of group C.The trial resin material had satisfying bonding strength and could reach bonding strength level of the commercial resin cement2 The integrity between root canal and cement of group A and B was more complete than the other group,so was the surface between fiber post and cement of group A and C.The micro-structure of bonding surface with trial resin was satisfying,but the bubble occasionally came out in the group A,and need improve operation form.3 The anti-fracture strength with different resins in non-vital teeth were:A 606.04±44.25N,B 538.68±53.29N,C 500.60±46.01N.There were statistical difference among them,and group B and A were much lower than group A. Therefore,resin materials had some in fluences in the anti-fracture strength and the trial resin in this experiment performed best. 4 There were no positive reaction to the trial resin material in acute general toxicity test;and the level of cytotoxicity was laid into 0-1.Furthermore.the results of oral mucous irritation test were also negative.
|
PDF Full Text Request