Extent of diffusion of organic molecules in the enamel tissue of dogs

Abstract

The objective of this study was to evaluate the extent of diffusion of organic molecules in the enamel tissue, of permanent teeth. The experimental study was performed in vivo on dogs. To the experimental dogs the molars on the right side of the lower jaw underwent enamel tissue reduction without additionally placing any tooth protection. Teeth on the left side of the lower jaw were left intact thus representing the control. After 12 months animals were sacrificed, experimental and control teeth extracted and the study of diffusion in vitro carried on. For that purpose an organic spin marker 4-amino - 2,2,6,6,-tetramethyl-piperdinyl 1-oxi (4-Amino-Tempo) was selected. The property of this marker is that it contains a nitroxide radical which is stable in a neutral and base environment, and due to the unbound spin of the free radical it is highly suitable for the electronic paramagnetic resonance method (EPR). Studies on the diffusion of organic spin markers in the enamel tissue are performed by submerging the prepared tooth in a water solution containing the marker substance. From the intensity of the EPR spectrum filmed after tooth withdrawal from the water solution, distribution diffusion time and penetration depth of marker molecules were established. Coefficients of organic spin marker diffusion and saturation concentrations of marker molecules in the enamel were determined. The observed variations in the area! and time for distribution of diffused molecules were explained by the binding possibility of the NO-radical from the marker molecule to the enamel tissue. The results of the experiment contained in this work contribute to a better understanding of the spin marker organic molecule movement through the enamel tissue which is controlled by the mechanism of diffusion and chemical bonding of the marker molecule to the enamel structure. The results of the experimental research also indicate the harmful effects of leaving the enamel tissue without protection.

U ovom radu prikazani su rezultati dubine difuzije organskih molekula u gleđnom tkivu stalnih zuba. Eksperimentalna istraživanja in vivo vršena su na psima. Na molarima desne strane donje vilice, kod svih životinja eksperimentalno je izvršena redukcija gleđnog tkiva, bez postavljanja zaštite, dok su zubi leve strane mandibule ostali intaktni i predstavljali su kontrolnu grupu. Period in vivo je trajao 12 meseci, posle čega su životinje žrtvovane, eksperimentalni I kontrolni zubi izolovani I nastavljeno ispitivanje procesa difuzije in vitro. U te svrhe izabran je organski spinski marker 4-amino-2,2,6,6-teramentil-piperidinil-1-oksi (4-Amino Tempo). Osobina ovog markera je da ima u svom sastavu nitroksidni radikal koji je stabilan u neutralnoj i baznoj sredini, a zbog nesparenog spina slobodnog radikala veoma je pogodan za istraživanja metodom elektronske paramagnetne resonance.