European Oral Research (Jan 2019)
Evaluation of fracture resistance of roots-filled with various root canal sealers at different time periods
Abstract
PurposeThe reinforcement effect of 3 various root canal sealers (AH 26, MTA Plus sealer andBioRoot RCS) and gutta-percha at different time periods (1 week and 1 month) wereevaluated in the present study.Materials and MethodsSingle-rooted, single-canalled, cracks-free 80 mandibular premolars weredecoronated to a length of 13mm. Group PC (positive control, n=10): samples wereleft unprepared and unfilled. Seventy samples were prepared by using the ProTaperRotary System up to F4. Group NC (negative control, n=10): samples were leftunfilled. Remaining 60 samples were assigned into 3 groups; Group 1: AH 26 + F4gutta-percha (GP); Group 2: MTA Plus sealer + F4 GP and Group 3: BioRoot RCS + F4GP. Filled samples were divided into subgroups according to storage time: Samplesin Groups 1A, 2A, and 3A were stored for 1 week; while Groups 1B, 2B and 3B werestored for 1 month at 100% humidity to allow the complete setting of the sealers(n=10, for each). A universal testing machine at a crosshead speed of 1.0 mm/minwas used for fracture testing. For each specimen, the force at the time of fracturewas recorded and the data were analyzed statistically.ResultsThe highest fracture resistance values were obtained in Group PC, while the lowestvalues were obtained in Group NC. Groups PC and NC were statistically differentfrom each other and from other groups, regardless of time (p<0.05). Fractureresistance values of Group AH 26/GP were statistically different from MTA Plussealer/GP (p<0.05) and were statistically similar with BioRoot RCS/GP, irrespective oftime. Within group comparisons revealed that there were no statistically differencesbetween samples filled with same sealer at different time periods.ConclusionRoot canal preparation caused decreased fracture resistance. All sealers increasedthe force values needed to fracture the filled samples compared to unfilled ones.Time factor had no effect on the fracture resistance values.
