Supplementary retreatment for filling removal in flattened root canals: An ex vivo microcomputed tomography study
Karina Ines Medina Carita Tavares, Airton Oliveira Santos-Junior, Jáder Camilo Pinto, Fernanda Ferrari Esteves Torres, Juliane Maria Guerreiro-Tanomaru, Mário Tanomaru-FilhoAbstract
Context:
Supplementary retreatment procedures may improve the removal of filling material from flattened root canals.
Aims:
The study aimed to compare the effectiveness of three supplementary retreatment techniques in flattened root canals by evaluating the reduction of remaining filling material as well as canal transportation and centralization.
Subjects and Methods:
Thirty maxillary second premolars with flattened root canals, defined by a buccolingual diameter at least four times greater than the mesiodistal diameter, were prepared using HyFlex EDM 25/0.08 and filled with gutta-percha with AH Plus sealer. After retreatment with ProDesign Logic (PDL) Retreatment and apical enlargement using PDL 40/0.05, the root canals were randomly allocated to one of three supplementary techniques (
Statistical Analysis Used:
Analysis of variance and Tukey tests, paired
Results:
Hedström file and FPDL significantly reduced the amount of remaining filling material, whereas XPFR showed no significant reduction. XPFR left significantly more remaining filling material than FPDL in the entire canal and all thirds, and more than the Hedström file in the apical third. No difference in canal transportation and centralization was detected among techniques.
Conclusions:
FPDL and Hedström file promoted greater filling material removal after retreatment of flattened canals while preserving canal geometry.