First Maxillary Molars MB Root Canal Morphology’s Effect On The Root Canal Obturation

First maxillary molars mesiobuccal canals’ morphology is verycomplicated， which causes pulpitis and periapical periodontitisfrequently, also a difficulty for RCT. This experiment types firstmaxillary molars MB and using cold lateral compaction and continuouswave technique RCT methods for different types, observing the rootcanals’ obturation for the theory basis on the RCT.Objective: To study first maxillary molars MB root canalmorphology when filled with cold lateral compaction and continuouswave technique.Methods80first maxillary molars were selected in Changchun area,with8-10#C pioneer file in mesiobuccal canal, digital periapical filmsin buccolingual direction was used to measure the root canal curvature;CT scanning of root canals was performed to measure and calculate theroot canal flatness when the root canals were prepared with Mtwo Ni-Tiinstruments. The teeth were divided in groups for different curvature andflatness as QWQB type, QWRB type, RWQB type and RWRB type.Cold lateral compaction (CLC) and continuous wave technique (CW)were used separately; CT scanning of the root canal was performed tocalculate the percentage of gutta-percha filled area (PGFA).Results: In CLC group, PGFA ascending as the order:QWQB<RWQB<QWRB<RWRB, there was no significant differencebetween various group（sP<0.05）；in CW group, there was no significantdifference between four groups（P>0.05）.The QWQB,QWRB and RWQB root canals’ PGFA in CW group were larger than those in CLCgroup（P<0.05）；there was no significant difference between CW groupand CLC group of RWRB root canal’s PGFA(P>0.05). The whole CWgroup is better than the CLC group（P<0.05）.Conclusion: Continuous wave technique is better than cold lateralcompaction when doing first maxillary molars root canal therapy.