Comparison of GPX with or without solvent and hand files in removing filling materials from root canals--an ex vivo study.
OBJECTIVE
The aim of this study was to compare GPX instruments and hand files for gutta-percha removal.


METHODS
Fifty maxillary central incisors with a single straight canal were instrumented and filled. The teeth were divided into 5 groups of 10 specimens each, according to the gutta-percha removal techniques: group 1: GPX (21-mm-long teeth); group 2: GPX and xylol as solvent (21-mm-long teeth); group 3: GPX (25-mm-long teeth); group 4: GPX and xylol as solvent (25-mm-long teeth); and group 5: hand files and xylol as solvent. The amount of time for gutta-percha removal and the number of fractured instruments were evaluated. Radiographs were taken, and the teeth were grooved longitudinally and split. The area of residual debris was measured using Sigma Scan software.


RESULTS
The time for filling material removal was significantly shorter when GPX was used (P < .05). Overall, hand files and solvent produced fewer remnants of filling materials (P < .05). In the GPX 25 mm-long teeth group, the filling material was not removed in the apical third.


CONCLUSIONS
Under the experimental conditions, the GPX instruments proved to be faster than hand instruments in removing root filling materials; however, hand instruments left a smaller amount of residual filling materials on the canal walls. The GPX instruments did not pull the gutta-percha beyond its tip.
Bauru School of Dentistry, University of São Paulo, Bauru, Brazil. lucianavb@uol.com.br
Luciana Viti
LV
Betti
Clovis Monteiro
CM
Bramante
Ivaldo Gomes
IG
de Moraes
Norberti
N
Bernardineli
Roberto Brandão
RB
Garcia
D003722:Dental Alloys / Q000737:chemistry; D003786:Dental Pulp Cavity / Q000473:pathology*; D003804:Dentin / Q000473:pathology; D004867:Equipment Design; D004868:Equipment Failure; D006171:Gutta-Percha / Q000737:chemistry*; D006801:Humans; D008422:Materials Testing; D019233:Retreatment; D012387:Root Canal Filling Materials / Q000737:chemistry*; D012389:Root Canal Obturation; D018915:Root Canal Preparation / Q000295:instrumentation*; D012997:Solvents / Q000627:therapeutic use*; D013193:Stainless Steel / Q000737:chemistry; D013997:Time Factors; D019227:Tooth Apex / Q000473:pathology; D014992:Xylenes / Q000627:therapeutic use; D015035:Zinc Oxide-Eugenol Cement / Q000627:therapeutic use
D003722:Dental Alloys; D012387:Root Canal Filling Materials; D012997:Solvents; D014992:Xylenes; D015035:Zinc Oxide-Eugenol Cement; D013193:Stainless Steel; D006171:Gutta-Percha