Quantitative study of the proportion of the pore volume of human fluorotic enamel filled by resin infiltrant.

AIM: Capillarity theory predicts that the pore volume infiltrated by a liquid in a body with tubular capillaries is directly proportional to the capillary radius. The expected volume available for infiltration is the loosely bound water volume, which can be related to the capillary radii. We tested the hypothesis that the proportion of the pore volume infiltrated by resin infiltrant (V(ratio)(resin)) is correlated and agrees with the proportion of the pore volume with loosely bound water ( [Formula: see text] ). DESIGN: Seven human fluorotic third molars (4 unerupted and 3 erupted; TF scores 4 to 7; fluoride content of inner coronal dentin ranged from 143 to 934mug Fluoride/g) were prepared and resin infiltration was performed during 10min in fluorotic enamel ground sections. Penetration depths were measured (polarizing microscopy and CLSM) and mineral volume and non-mineral volumes were measured at histological points (n=92) along transversal lines traced from the enamel surface to the enamel-dentin junction. RESULTS: No well-mineralized surface layer was found. Infiltration depths ranged from 250mum to 900mum. V(ratio)(resin) ranged from 1.8 to 17.7% (mean of 10.13%+/-4.1%), was lower than [Formula: see text] (p<0.00001 Hedge's g=1.51, 95% CI: 1.18/1.83), and correlated positively with [Formula: see text] (R=0.684; 95% CI: 0.557/0.780) and negatively with the air volume remained after infiltration (R=-0.79; 95% CI: -0.698/-0.780). [Formula: see text] exceeded V(ratio)(resin) in 5% (1/4 of [Formula: see text] ) on average. CONCLUSION: [Formula: see text] and V(ratio)(resin) correlated well, but lacked good agreement. Organic matter, firmly bound water and air remained in enamel pores after resin infiltration.