Effect Of Immediate And Delayed Post Space Preparation On Apical Dye Leakage Using Two Different Sealers

Objective:Using dye penetration in a pressure-driven system.Compare the effect of immediate versus delayed post space preparationon the permeability of remaining endodontic obturation with different sealer.Methods:One hundred and twenty-eight single rooted premolars were instrumented with step-back techniqueand obturated by lateral compaction technique.The teeth were divided into eight groups with randomized block design.Group A1(n=16),obturated with gutta-percha and AH-plus sealer,immediate post space preparation.GroupA2(n=16),obturated with gutta-percha and pro-root MTA sealer,immediate post space preparation.GroupB1(n=16),obturated with gutta-percha and AH-plus sealer sealer,delayed post space preparation.GroupB2(n=16),obturated with gutta-percha and pro-root MTA sealer,delayedpost space preparation.GroupC1(n=16),obturated with gutta-percha and AH-plus sealer,no post space space preparation.GroupC2(n=16),obturated withgutta-percha and pro-root MTA sealer,no post space preparation.Negative group (n=16),obturated with gutta-percha and AH-plus sealer,no post space preparation.Positive group (n=16),obturated with gutta-percha but no sealer,no post space preparation.Post space preparation was finished with3#peeso reamer leaving5mm of apical filling.All specimens were sealed with ZOE temporary filling material,and exposed to synthetic tissue fluid at37°C for4weeks.Beforeleakage assessment,all specimens were thermocycled for500timesat5°C and55°C in water baths.Each group divided into two subgroups,to investigate leakage from cervix–to–apex and from apex–to–cervix.With dye penetration in a pressure-driven system.The teeth were then cleared,the depth of dye penetration was measure with stereomicroscope.Results:The leakage from cervix–to–apex1.GroupA1(AH-plus sealer/immediate post space preparation,11.21±0.96mm)had a less leakagethan groupB1(AH-plus sealer/delayed post space preparation,12.53±1.37mm),and a significant difference was confirmed (P<0.05).2.There was no significant difference between groupA1(AH-plus sealer/immediate post space preparation,11.21±0.96mm)and groupC1(AH-plus sealer/no post space preparation,10.62±0.54mm);more leakage was found in groupB1(AH-plus sealer/delayed post space preparation,12.53±1.37mm)than groupC1(AH-plus sealer/no post space preparation,10.62±0.54mm),and a significant difference was confirmed (P<0.05).3.There was no significant difference between groupA2(pro-root MTA sealer/immediate post spacepreparation,11.00±0.88mm),groupB2(pro-root MTA sealer/delayed post space preparation,10.96±0.76mm)andgroupC2(pro-root MTA sealer/no post space preparation,10.18±0.63mm)(P>0.05).4.There was a significant difference between groupB1(A H-plus sealer/delayed post space preparation,12.53±1.37mm)and groupB2(pro-root MTA sealer/delayed post space preparation,10.96±0.76mm)in the delayed postpreparation(P<0.05).5.In the groups with immediate post space preparation and no post preparation,no significantdifference was found between groupA1(AH-plus sealer/immediate post space preparation,11.21±0.96mm)and groupA2(pro-root MTA sealer/immediate post space preparation,11.00±0.88mm)or groupC1(AH-plus sealer/no post space preparation,10.62±0.54mm)and groupC2(pro-root MTA sealer/no post space preparation,10.18±0.63mm)(P>0.05).Theleakage from apex–to–cervix1.The leakage in groupA1(AH-plus sealer/immediate post space preparation,11.21±0.96mm) and groupB1(AH-plus sealer/delayed post space preparation,12.53±1.37mm)was much more than that in groupC1(AH-plus sealer/no post space preparation,10.62±0.54mm),and a significant difference was confirmed (P<0.05).But there was no significant difference between groupA1(AH-plus sealer/immediate post space preparation,11.21±0.96mm) and groupB1(AH-plus sealer/delayed post space preparation,12.53±1.37mm)(P>0.05).2.There was no significant difference among groupA2(pro-rootMTA sealer/immediate post space preparation,11.00±0.88mm)、groupB2(pro-root MTA sealer/delayed post space preparation,10.96±0.76mm)and groupC2(pro-root MTA sealer/no post space preparation,10.18±0.63mm)（P>0.05）.3.In the groups of immediate post space prepar ation and delayed post preparation,the groups sealed with pro-rootMTA (groupA2,groupB2)had a better sealing ability than those withAH-plus(groupA1，groupB1),significant differences were found in these groups(P<0.05).conclusions:1.There was more leakage after delayed post space preparation in the group sealed with AH-plus.Immediate post space preparation made a negative effect on the leakage from apex–to–cervix.2.The roots sealed with MTA after post space preparation did not differ from those with no post space preparation.MTA had a better sealing ability than AH-plus.3. It’s better to prepare the post space immediately after root canal therapy,because that person has become intimately familiar with the root canal anatomy. Operation will be more easy to reduce the negative impact of improper operation...