Diffusion of resin monomers through human carious dentin in vitro

Abstract

The diffusion of 2-hydroxyethylmethacrylate (HEMA) and triethylene glycol dimethacrylate (TEGDMA) from light cured bonding resin-composite resin restorations through human carious dentin was investigated. Extracted human molar teeth with different degrees of caries were obtained from consenting donors. Teeth were classified into three groups according to caries severity (mild, moderate and severe) using subjective criteria. The outer carious lesions were then removed guided by a proprietary caries detector dye. Teeth with exposure of the pulp space after caries removal were excluded from the study. A polypropylene chamber was attached to the cemento-enamel junction of each tooth to contain 1 ml distilled water. Each cavity was restored with a HEMA containing bonding resin then a TEGDMA-containing resin composite. Water samples were retrieved over a time course and analyzed by high performance liquid chromatography. There was great variation between teeth in HEMA and TEGDMA permeability. The cumulative amounts released were of similar magnitude to those observed in non-carious teeth for the mild and moderately-severe groups. However, the cumulative amounts released were markedly greater in severely carious teeth than in those with moderate or mild caries.

Morphological and Mechanical Characterization of the Acid-base Resistant Zone at the Adhesive-dentin Interface of Intact and Caries-affected Dentin

“…Since the caries-affected intertubular dentin is already partially demineralized and more porous, caries-affected dentin is softer than normal dentin (Ogawa & others, 1983;Hamid & Hume, 1997), and this was confirmed in this study. The intertubular dentin of caries-affected dentin is more permeable to primer than that of normal dentin.…”

Bioavailability of Components of Resin-Based Materials Which Are Applied To Teeth

“…Measurement of such diffusion in carious teeth in vitro (Hamid and Hume, 1995) showed a moderate reduction in HEMA and TEGDMA permeability beneath mild and moderate caries but not, however, in teeth with severe caries lesions, where permeability was markedly higher. This matter requires further investiga-tion, Tagami et al (1992) reported that the hydraulic conductance of the dentin beneath caries lesions was greatly reduced compared with that of normal dentin.…”

In Vitro Analysis of AHPlus and MM-Seal by ESR and Thermoanalytical Methods

“…In vitro methods have been recommended by the American National Standards Institute, the American Dental Association [15] for evaluation of the cytotoxicity of endodontic materials. For biomedical applications using new polymeric composite materials, it is significant to know quantively the amount of residual monomer release from the surface of the polymerized composite, because of the likely harmful effects of residual monomers on tissues [16][17][18][19][20][21][22][23][24][25]. It is well known that oxygen presence inhibits free radical polymerization of monomers of the resin.…”