Effect of desensitizing toothpastes on dentin

Abstract

The objective of this study was to analyze the effects of toothbrushing with desensitizing toothpastes on dentin permeability and dentinal tubule occlusion. Fifty rats provided two hundred incisor teeth divided into five groups: DW, brushed with distilled water (control); FT, brushed with fluoride toothpaste; SCT, brushed with strontium chloride toothpaste; PCT, brushed with potassium citrate toothpaste; and PNT, brushed with potassium nitrate toothpaste. Cavities were prepared to expose the dentinal tubules, and the incisor teeth were brushed using the experimental agents. After each treatment, Evans blue dye solution was applied to the teeth. Dentin permeability was analyzed using scanning electron microscopy and energy-dispersive X-rays (EDX). There were significant differences (p < 0.0001, ANOVA) among the groups regarding dentin permeability, number of dentinal tubules, diameter of dentinal tubules, and opened tubular area. In the SCT, PCT and PNT groups, opened and partially occluded tubules, deposits, and a few smear layers were observed. In the DW and FT groups, most of the dentinal tubules were open, with no deposits or smear layers on the dentin. EDX revealed peaks of calcium and phosphorus in all of the groups, as well as traces of strontium in the SCT group and of potassium in the PCT and PNT groups. Desensitizing toothpaste decreased dentin permeability, although it produced only partial dentin tubule occlusion.

Evaluation of ex vivo effectiveness of commercial desensitizing dentifrices

“…Improvements in the oral health status of the worldwide population are currently noteworthy, as well as the efficacy of dental treatments, which leads to lower rates of caries and periodontal diseases, thus contributing to the maintenance of the teeth in the oral cavity for longer (1). These factors, combined with the longer life expectancy of the world population, can indirectly lead to increased rate of dentin hypersensitivity (DH), since the higher the individual’s age and the number of teeth he has, the greater the chances of having DH (1,2).…”

“…These factors, combined with the longer life expectancy of the world population, can indirectly lead to increased rate of dentin hypersensitivity (DH), since the higher the individual’s age and the number of teeth he has, the greater the chances of having DH (1,2). DH is described as a short, severe pain with fast onset, which may be either localized or generalized (3,4).…”

“…Namely, we can cite the following applications: high or low intensity laser (4), fluoride varnish (6), oxalate (6,7), composite resin (5) and glass ionomer (5), in addition to periodontal surgeries (5,8). However, the use of desensitizing dentifrices is the first choice for most patients (1,4,6,9). It is noteworthy that these are dose dependent, requiring routine applications (10).…”

“…It is noteworthy that these are dose dependent, requiring routine applications (10). Another important fact is that dentin, when hypersensitive, features tubules with diameters of 0.83 µm, i.e., the dentifrices should ideally have particles with an average diameter such that they can penetrate the dentinal tubules, thus facilitating the release of chemicals which will bind to dentin (1,4,8). To the best of the authors’ knowledge, studies evaluating the size and stability of the particles with regards to commercial desensitizing dentifrices have not yet been conducted.…”

A Comparison of Dentin Tubule Occlusion Properties of Dipotassium Oxalate against Potassium Nitrate: An In Vitro Study

“…Their study revealed that potassium nitrate could partially obstruct dentinal tubules after 4 days of daily application. 21 James et al utilized extracted human molars and subjected them to toothpaste and mouthwash that contained potassium nitrate. Through SEM analysis, they were able to show that human dentinal tubules show occlusion within 3 days of application.…”