In-vitro evaluation of fluoride release and caries inhibition of glass ionomer modified with chlorhexidine diacetate

Dental caries still remains a major public health problem despite the widespread use of fluoride. Glass ionomer cements aredental restorative materials with an antibacterial effect. This group of restorative materialprovides anti cariogenic effect by fluoride release. Chlorhexidine hasincreased susceptibility of antibacterial andis the most suitable agent in reducing mutans streptococci. Chlorhexidine retains in oral structures for longer duration and is slowly released providing prolonged antibacterial effect than other agents.

To evaluate the effect of Glass ionomer combined with chlorhexidine diacetate on caries mechanism by using polarized microscope.

To evaluate the amount of fluoride release from Glass ionomer combined with chlorhexidine by using UVspectrophotometry method.

36 human incisors were selected. Teeth were divided into five groups. The middle 2 x2 mm of the facial enamel of each tooth was isolated for the purpose of adhesion of restorative material. After bonding the specimens were kept for 4 days in acidic solution to induce artificial lesion formation. All the specimens were mountedin blocks of self cure acrylic and subjected to sectioning using a hard tissue microtome. From each specimen, 150 μm thick sections were taken and fixed on to the slides and observed under polarized light microscope for demineralization.

A total of thirty two disk shaped specimens using two different glass ionomer materials were made and divided into four groups. The specimens were fabricated by condensing the glass ionomer cement in the metal mold. Specimens were then stored in distilled water at 37°C for 24 hours and 7 days to ensure complete fluoride release. Baseline fluoride measurement of all specimens was made using UV spectrophotometer.

Mean values were compared by one-way analysis of variance (ANOVA)

Among the four groups of fluoride releasing restorative materials, RMGIC+CHX Diacetate showed less area of demineralization followed by conventional GIC+CHX

The amount of fluoride release was more in the RMGIC+CHX and conventional GIC+CHX

This combination showed increased fluoride release in first 24hrs which is decreased at 7 days.

The cariostatic property is more with RMGIC+CHX and the fluoride release is also more with RMGIC+CHX group over the extended period of time. Though the values are not statistically significant, the choice of restorative material could be RMGIC+CHX due to their advantageous properties like setting on demand, less moisture sensitivity etc. The added CHX can also prevent plaque and calculus formation on the tooth near restoration.