L. Bjorndal et A. Thylstrup, A STRUCTURAL-ANALYSIS OF APPROXIMAL ENAMEL CARIES LESIONS AND SUBJACENT DENTIN REACTIONS, European journal of oral sciences, 103(1), 1995, pp. 25-31
The present study examines the correlation between caries lesions in e
namel and the corresponding dentin reactions in proximal tooth surface
s with lesions ranging from enamel lesions to cavitations without dent
in exposure. Using quantitative imbibition technique, the highest degr
ee of tissue porosity, irrespective of lesion activity, was always not
ed along a Central-Traverse (CT), which followed the direction of the
rods from the deepest point of penetration to the surface. The conical
shape of approximal enamel lesions can thus be seen as the result of
systematic variations in porosity along the rods determined by the spe
cific interproximal environment. The initial dentin reaction, related
to the enamel lesion approaching the enamel-dentin junction (EDJ), was
seen as a local dentin translucency where the CT crossed the EDJ. Res
ults from histomorphometric analyses revealed that, when the enamel le
sions reached the EDJ, brownish discoloration in the dentin never exce
eded the histologic contact area between the enamel lesion and the EDJ
. In relation to the less advanced parts of the individual enamel lesi
on, the dentin responded with formation of translucent dentin. These r
eactions did not occur beyond an area determined by lines in the direc
tion of the rods from the peripheral part of the enamel lesion towards
the EDJ. The results did not support the view that dentin caries spre
ads along the enamel-dentin junction. The peripheral dentin translucen
cy is therefore generated by stimuli transmitted along the rods of the
less advanced parts of the enamel lesions.