Analysis of apical root transportation associated with ProTaper Universal F3 and F4 instruments by using digital subtraction radiography.
BACKGROUND
The aim of this study was to assess the occurrence of apical root transportation after the use of ProTaper Universal rotary files sizes 3 (F3) and 4 (F4).


METHODS
Instruments were worked to the apex of the original canal, always by the same operator. Digital subtraction radiography images were produced in buccolingual and mesiodistal projections. A total of 25 radiographs were taken from root canals of human maxillary first molars with curvatures varying from 23-31 degrees. Quantitative data were analyzed by intraclass correlation coefficient and Wilcoxon nonparametric test (P = .05).


RESULTS
Buccolingual images revealed a significantly higher degree of apical transportation associated with F4 instruments when compared with F3 instruments in relation to the original canal (Wilcoxon test, P = .007). No significant difference was observed in mesiodistal images (P = .492).


CONCLUSIONS
F3 instruments should be used with care in curved canals, and F4 instruments should be avoided in apical third preparation of curved canals.
Kunert
Gustavo Golgo
GG
School of Dentistry, Universidade Luterana do Brasil (ULBRA), Canoas, RS, Brazil. g.kunert@click21.com.br
Camargo Fontanella
Vania Regina
VR
de Moura
Abílio Albuquerque Maranhão
AA
Barletta
Fernando Branco
FB
D003786:Dental Pulp Cavity / Q000033:anatomy & histology / Q000000981:diagnostic imaging*; D006801:Humans; D008422:Materials Testing; D008963:Molar / Q000000981:diagnostic imaging; D009811:Odontometry; D019252:Radiography, Dental, Digital / Q000379:methods*; D018915:Root Canal Preparation / Q000295:instrumentation* / Q000379:methods; D013382:Subtraction Technique; D019227:Tooth Apex / Q000033:anatomy & histology / Q000000981:diagnostic imaging*