Dentin permeability of the apical third in different groups of teeth

Rodrigo Gonçalves Ribeiro,Melissa Andreia Marchesan,Jesus Djalma Pécora,Ricardo Gariba Silva,Manoel D Sousa-Neto

doi:10.1590/s0103-64402010000300007

Rodrigo Gonçalves Ribeiro, Melissa Andreia Marchesan + Show 3 more

Open Access

https://doi.org/10.1590/s0103-64402010000300007

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Abstract

This ex vivo study evaluated dentin permeability of the root canal in the apical third of different human groups of teeth. Eighty teeth were used, 8 from each dental group: maxillary and mandibular central incisors, lateral incisors and canines, maxillary first premolars (buccal and palatal roots), mandibular first premolars, and maxillary and mandibular second premolars, totalizing 88 roots that were distributed in 11 groups. The root canals were instrumented, irrigated with 1% NaOCl and 15% EDTA. Roots were immersed in 10% copper sulfate for 30 min and then in 1% rubeanic acid alcohol solution for the same period; this chemical reaction reveals dentin permeability by the formation of copper rubeanate, which is a dark-colored compound. Semi-serial 100-µm-thick cross-sections were obtained from the apical third of the roots. Five sections of each apical third were washed, dehydrated, cleared and mounted on glass slides for examination under optical microscopy. The percentage of copper ion infiltration and the amount of tubular dentin were quantified by morphometric analysis. The penetration of copper ions in the apical third ranged from 4.60 to 16.66%. The mandibular central and lateral incisors presented the highest dentin permeability (16.66%), while the maxillary canines and mandibular second and first premolars presented the lowest dentin permeability (4.60%, 4.80% and 5.71%, respectively; p<0.001). The other teeth presented intermediate permeability. In conclusion, dye penetration into dentin tubules at the apical region is strongly dependent on the group of teeth evaluated.

Highlights

Different methodologies have been used to evaluate the root canal dentin permeability before and after the use of irrigating solutions, i.e., radioisotopes [1], histochemical method [2,3], and dyes [4,5].The variations in dentin microstructure, its chemical composition, the formation of dentin tubules, the deposition of the mineralized matrix during dentinogenesis, the inherent permeability of dentin, and the different types of dentin have been extensively investigated [5,6,7,8,9,10]
Dentin permeability can be influenced by physiologic changes that lead to the formation of sclerotic dentin [4,5,6]
Based on the fact that the apical third of the root canal is less permeable than the middle and cervical thirds [2,11,12], this ex vivo evaluated the apical permeability of the different groups of teeth and the pattern of distribution of tubular and sclerotic dentin

Summary

Introduction

Different methodologies have been used to evaluate the root canal dentin permeability before and after the use of irrigating solutions, i.e., radioisotopes [1], histochemical method [2,3], and dyes [4,5].The variations in dentin microstructure, its chemical composition, the formation of dentin tubules, the deposition of the mineralized matrix during dentinogenesis, the inherent permeability of dentin, and the different types of dentin have been extensively investigated [5,6,7,8,9,10]. Different methodologies have been used to evaluate the root canal dentin permeability before and after the use of irrigating solutions, i.e., radioisotopes [1], histochemical method [2,3], and dyes [4,5]. Dentin permeability can be influenced by physiologic changes that lead to the formation of sclerotic dentin [4,5,6]. Penetration of microorganisms into dentin tubules can be influenced by the type of dentin. Based on the fact that the apical third of the root canal is less permeable than the middle and cervical thirds [2,11,12], this ex vivo evaluated the apical permeability of the different groups of teeth and the pattern of distribution of tubular and sclerotic dentin

Methods

Results

Conclusion