The effectiveness of iontophoresis in enhancing remineralisation of carious lesions

Abstract

Tooth decay is an outcome of the acid from sugar on the dental plaque accumulated on the tooth structure. When plaque is left undisturbed, the acid starts removing minerals from the tooth structure (demineralisation), establishing caries with no cavity and ending with the destruction of the tooth structure if no treatment has taken place before then. Teeth have two anatomical structures: a crown and a root. The dental plaque shows more build-up on the root surface, reflecting the importance of taking care of root carious lesions in an early stage. As the lifespan of human beings becomes longer and people keep their teeth longer, the root surface is increasingly exposed as a result of ageing, leading to high risk of root caries. This research aims to compare the conventional remineralisation methods, which have been widely used, with a novel remineralisation method using an electrical current, to see if there is any enhancement in the remineralisation process specifically impacting root caries. Experiments using natural tooth caries will create many variations, leading to difficulty comparing outcomes. Therefore, developing artificial caries on extracted teeth in the laboratory will help to limit variations. This method was designed to mimic a typical caries lesion in a patient’s mouth. 30 human extracted teeth, free of caries, were used in this research. The tooth samples were divided into seven groups as follows: healthy teeth, artificially decayed teeth without treatment, artificially decayed teeth subjected to a remineralisation solution without additives, artificially decayed teeth subjected to remineralisation solution with additives, artificially decayed teeth subjected to remineralisation paste tooth mousse, artificially decayed teeth subjected to remineralisation paste tooth mousse plus contain fluoride, and artificially decayed teeth subjected to a remineralisation solution with a nano-hydroxyapatite remineralisation solution with and without using an electrical current. Following the sample preparations, each group was subjected to three types of measurement to give reliable and comparable results. The following measurements were applied to each specimen: microhardness test to analyse the surface hardness, scanning electron microscopy (SEM) to produce informative surface topography images, and energy dispersive X-ray spectroscopy (EDX) to quantify the elemental composition of the samples. The findings of the measurements reported in this research reveal that remineralisation was achieved with both the conventional method and the method using the electrical current with no presumed difference. Remineralising enamel by applying an electrical current also interacted favourably, as has been shown in other studies. However, it was also found in this research that using an electrical current for remineralising root dentine does not enhance the dentine remineralisation.