Effect of smear layer removal on the diffusion permeability of human roots.
Ten human maxillary incisors, extracted because of periodontal disease or nonrestorable caries, were obtained and instrumented to a size #70 K-Flex file at the working length using a standard stepback technique. Tritiated water (3H2O) was placed in the root canals and allowed to diffuse to the external surface of the roots until it reached a constant rate. The smear layer in each of the experimental roots was then removed using 0.5 M EDTA followed by 5.25% sodium hypochlorite (NaOCI). The constant rate diffusion of 3H2O was remeasured. The roots were then stored in deionized H2O for 2 months and the constant rate diffusion of 3H2O was remeasured. A statistically significant difference was noted between all three groups. A decrease in the diffusion permeability of the root to 3H2O was noted immediately after smear layer removal and the highest permeability was recorded after storage in the deionized water for 2 months.
Galvan
D A
DA
U.S. Army Dental Activity, Ft. Leonard Wood, MO.
Ciarlone
A E
AE
Pashley
D H
DH
Kulild
J C
JC
Primack
P D
PD
Simpson
M D
MD
D003804:Dentin / Q000502:physiology; D003806:Dentin Permeability; D004058:Diffusion; D006801:Humans; D016369:Smear Layer; D014092:Tooth Root / Q000502:physiology*; D014867:Water
D014867:Water