ABSTRACT
This study evaluated the effects of ultrasonic activation (US) associated to glycolic acid (GA) on smear layer, dentin structure and bond strength (BS) of filling/restorative material to root dentin. The roots were used for antimicrobial activity, dentin structure and BS evaluation, being distributed into seven groups, according to irrigation protocols: G1:DW+US; G2:17% EDTA; G3:QMix; G4:17% GA; G5:17% EDTA+US; G6:QMix+US; G7:17% GA+US. Scanning electronic microscopy, transmission electronic microscopy and push-out were performed, with specific statistical analysis for each evaluation. The highest smear layer removal occured in Groups 6 and 7 (p<0.05), and the largest collagen dispersion in Group 7, being similar to Group 2 and 5 (p>0.05). The highest BS of filling and restorative material occurred in Groups 6 and 7, and Groups 5, 6 and 7, respectively, being similars between them (p>0.05). The use of GA+US promoted effective smear layer removal and dentin structure preservation, improving the BS of filling/restorative material to root dentin.
Subject(s)
Acids , Edetic Acid , EndodonticsABSTRACT
Objective To evaluate the bond strength of GuttaFlow sealers to root canal walls after final rinse with two novel fi nal irrigation regimens, QMiX and 17%EDTA+0.2%Cetrimide (CTR). Methods Thirty single-canal teeth were prepared chemomechanically using 5.25% sodium hypochlorite (NaOCl) as root canal irrigants. The teeth were then randomly distributed into three groups(n=10)according to the final irrigation protocol:QMiX group,17% EDTA followed by CTR group and control group(normal saline,NS).After the filling with GuttaFlow using a lentulo spiral,the roots were transversally sectioned to obtain 2 mm thick dentinal slices.Then a push-out bond strength test was carried out,and failure mode was determined at×24 magnification.Results The push-out bond strength was significantly higher in QMiX group than that of EDTA+CTR group and NS group(P<0.05),and no significant difference was observed between EDTA+CTR and NS groups(P>0.05).The failure patterns were mainly mixed.Conclusion The QMiX,as the final irrigant,can improve the bond strength of silicone-based sealer GuttaFlow.
ABSTRACT
Objective:To evaluate the bond strength of root canal sealer AH Plus and GuttaFlow to root canal walls after final rinse with 4 different final irrigation regimens.Methods:60 teeth with single-canal were prepared chemomechanically using 5.25% sodi-um hypochlorite (NaOCl)as root canal irrigant.The teeth were then randomly distributed into 3 groups(n =20)according to the final irrigation protocol:1 7% EDTA followed by 2% chlorhexidine(CHX)(group 1 ),5.25% NaOCl followed by 1 7% EDTA(group 2), 0.9% normal saline(NS)(group 3).The root canals were then filled with sealers using a lentulo spiral and each group was distribu-ted into 2 subgroups according to the sealers(n =1 0):a.AH Plus;b.GuttaFlow.The roots were transversally sectioned to obtain 2mm thick dentinal slices.Then a push-out bond strength test was carried out and failure mode was observed by stereomicroscope. Results:The bond strength of AH Plus was significantly higher than that of GuttaFlow(P 0.05).When the root canals were filled with GuttaFlow,the push-out strength of group 1 ,2 and 3 was (1 .40 ±0.59)MPa, (1 .26 ±0.62)MPa and (1 .05 ±0.27)MPa respectively(P >0.05).The failure modes of AH Plus and GuttaFlow were both mainly mixed,but the proportion of adhesive failure in the canals filled with GuttaFlow were obviously higher than AH Plus.Conclusion:The bond strength to root canal wall of GuttaFlow is significantly lower than that of AH Plus.1 7% EDTA followed by 2% CHX as fi-nal irrigant can reduce the bond strength of AH Plus but has no marked effect on GuttaFlow.