Abstract:

To study the morphology of first maxillary molar main  mesiobuccal(MB) root canal and to observe the clinical effects of cold lateral condensation(CLC) and continuous wave obturation(CW).Methods 80 first maxillary molars were selected in Changchun area;with 8-10# C pioneer file in MB canal,the digital periapical films in buccolingual direction were used to measure the root canal curvature;CT scanning of root canals was performed to measure and calculate the root canal flatness when the root canals were prepared with Mtwo Ni-Ti instruments.The teeth were divided in groups for different curvature and flatness as QWQB type(n=16),QWRB type(n=26),RWQB type(n=14) and RWRB type(n=24).CLC and CW  technique were used separately,and CT scanning of the root canal was performed to calculate the percentage of gutta-percha filled area (PGFA).Results In CLC group,the PGFA was decreased   as the order: QWQB0.05）.The PGFA of QWQB,QWRB and RWQB root canals in CLC  group were smaller  than those in CW  group（P<0.05）；there was no significant difference in the PGFA of RWRB root canal between CW group and CLC group (P>0.05).The whole PGFA in CW group was better than that in  CLC group（P<0.05）.Conclusion The effect of CW technique is better than that of CLC  in treatment of first maxillary molar root canal.

Key words: first maxillary molar, main mesiobuccal canal, morphology, root canal obturation