Retreatment efficacy of gutta-percha removal using a clinical microscope and ultrasonic instruments: part I--an ex vivo study.
OBJECTIVE
This study compared the efficacy of gutta-percha/sealer removal from endodontically treated extracted human teeth with and without the aid of a clinical operating microscope/ultrasonic instruments.


METHODS
Forty human extracted maxillary central incisors were prepared using a modified crown-down technique and filled with lateral compactation. Teeth were divided into 2 groups: group I, re-treated using a conventional technique with burs and solvent; and group II, re-treated using a conventional technique with burs and solvent plus clinical operating microscope/ultrasonic tips. Teeth were split longitudinally and photographed, and coded photos transfered to a computer workstation. Total canal space and remaining gutta-percha/sealer were quantified, and ratio of remaining filling material and root canal periphery was computed. Mean percentage of remaining gutta-percha/sealer in each group was compared using analysis of variance.


RESULTS
The average percentage of remaining gutta-percha/sealer was 25.21% in group I and 9.31% in group II, showing a statistically significant difference (P = .05).


CONCLUSIONS
The use of the dental operating microscope and ultrasonic tips removed the filling material from root canal walls better, but all examined teeth, in both groups, had remaining filling material on canal walls.
de Mello Junior
Jose Eduardo
JE
Center for Dental Research, São Leopoldo Mandic, Campinas, Brazil.
Cunha
Rodrigo Sanches
RS
Bueno
Carlos Eduardo da Silveira
CE
Zuolo
Mario Luis
ML
D003786:Dental Pulp Cavity / Q000473:pathology*; D006171:Gutta-Percha / Q000627:therapeutic use*; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008866:Microsurgery / Q000295:instrumentation*; D010781:Photography; D019233:Retreatment; D012387:Root Canal Filling Materials / Q000627:therapeutic use*; D012388:Root Canal Irrigants / Q000627:therapeutic use; D018915:Root Canal Preparation / Q000295:instrumentation*; D012973:Sodium Hypochlorite / Q000627:therapeutic use; D012997:Solvents / Q000627:therapeutic use; D014464:Ultrasonic Therapy / Q000295:instrumentation*
D012387:Root Canal Filling Materials; D012388:Root Canal Irrigants; D012997:Solvents; D006171:Gutta-Percha; D012973:Sodium Hypochlorite