RESUMEN
Objective:To evaluate the effects of resistance of bonded amalgam restorations to fracture after treatment.Methods: Fifty healthy extracted maxillary teeth were selected,ten of them as control.The remainder were prepared a mesial occlusal distal(MOD) cavity.All of the teeth were then divided into five groups: 1st group: control;2nd group: direct restoration;3rd group: Luting;4th group: GC Fuji Ⅱ;5th group: RelyX ARC.All specimens were placed in a 37 degree centigrade humidity chamber for 72 h.The samples were thermocycled for 2 500 cycles at a temperature of 5 ℃ and 55 ℃.The samples use fatigue testing and observe by scanning electron microscope.Results:The preparation and restoration groups required significantly less force to fracture than the control group.The group with glass-ionomer cement bonding and composite resin bonding showed no significantly fracture resistance.Conclusion:Bonded amalgam restoration is a effective technique.At the same time glass-ionomer cement bonding and composite resin bonding shows no significantly fracture resistance.
RESUMEN
Objective: To evaluate fracture resistance of teeth restored with inlay restorations of direct and indirect composite resin. Methods:Three dimensional finite element analysis (3D FEA) was used in present research. Two types of load were applied to investigate the change of tooth fracture resistance after restored with MOD inlay. Group 1,2,3,and 4 were restored with four kinds of materials:group 1,indirect composite resin inlay( Tescera, Bisco USA);group 2, direct composite inlay(Renew Bisco USA);group 3,ceramic; and group 4, Co-Cr alloy. Defect tooth or intact one was served as the control group. Results:Tooth fracture resistance in group 1,2,3 and 4 were improved, Fracture resistance in group 1 and 2 were similar to intact tooth group, while the fracture resistance in group 3 and 4 was different effect when compared to intact tooth. Conclusion: Both direct and indirect composite resin inlay could strengthen fracture resistance of restored teeth. No obvious difference between direct and indirect composite resin on tooth resistance was found.