Acid Profiles and pH of Carious Dentin in Active and Arrested Lesions

Abstract

Organic acids in caries lesions play important roles in initiation and progress of dental caries. We investigated relationships between clinical types of dentin caries and acid profile or pH in the lesions. Caries lesions in dentin from 76 permanent teeth were classified into active, arrested, situated beneath a restoration, and unclassified types. The pH of carious dentin was distinctly lower than that of sound dentin (p < 0.001). Carious dentin with a high percentage of lactate had a lower pH than that with a high percentage of acetate and propionate (p < 0.001). Dentin from active lesions showed a mean pH of 4.9, and the dominant acid was lactate (mean percentage, 88.2). In contrast, carious dentin from arrested lesions showed a higher pH, 5.7, with acetate and propionate as the dominant acids (mean percentages of acetate and propionate, 64.0 and 18.2, respectively). The acid profile (mean percentages of acetate and propionate, 54.0 and 27.7, respectively) and pH (mean 5.8) of carious dentin sampled from lesions beneath a restoration were similar to those of dentin from arrested lesions. This study showed a clear relationship between clinical classification of dentin caries and acid profile and pH, suggesting that both factors are important in dentin caries etiology.

The Effect of Antibacterial Monomer MDPB on the Growth of Organisms Associated with Root Caries

“…Whatever was the basis for the inhibition of MDPB activity, this might have effects on the activity of MDPB in vivo. The pH of infected dentin associated with carious lesions is below 5.0, and in some instances it is below 4.0 16) . In these circumstances, the concentration of MDPB either in solution or as a component of a dental material required to inhibit the growth of organisms in dentin may have to be greater than previously considered.…”

A Study of the Effect of Hydrogen Sulfide on Conventional and Resin-Modified Glass-Ionomer Dental Cements

“…discrete F -ions, is significantly reduced [3,4]. This appears to be related to the increase in aluminium under acidic conditions, and the formation of complex species such as AlF 6 3-, or other fluoro-alumino species, such as AlF 2 + and AlF 2+ , as suggested by Crisp and Wilson [5].…”

“…This is the acid that is mainly responsible for dental caries [6], and is also the acid that has been used in erosion testing of cements [7]. However, it is not the only acid that may be present in the mouth.…”

“…However, it is not the only acid that may be present in the mouth. Other organic acids, such as ethanoic (acetic) and propionic acids, are known to be associated with caries, though they tend to occur at much lower concentrations that lactic [6]. In addition, hydrogen sulfide is known to occur under certain conditions.…”

Neutralizing effect by resin-based materials containing silane-coated glass fillers

“…Accordingly, outer lesions recognized on the exposed tooth surfaces are formed in a low pH environment, below 5.5, caused by bacteria in the medium. As active caries is known to occur at a pH of approximately 4.9 and to become arrested when the pH is shifted to approximately 5.7 26) , resin-based material with a neutralizing ability may contribute to the buffering of acids produced by cariogenic bacteria. Undoubtedly the resin-based material coated with 3-aminopropyltrimethoxysilane raised the pH to a significant level that would arrest caries for measurement of pH value in 5 ml de-ionized water.…”