Remineralization of Enamel Subsurface Lesions

The aim of the present study was to determine the remineralization effects of xylitol chewing gum containing funoran and calcium hydrogenphosphate on enamel subsurface lesions in humans. The study was a double-blind, randomized, cross-over design, with 4 types of gum: (1) xylitol gum, (2) xylitol gum containing funoran and calcium hydrogenphosphate, (3) sugar gum, and (4) gum base as a control. Seven subjects were instructed to wear removable lingual appliances, with half-slab insets of human enamel containing demineralized subsurface lesions. They were told to chew gum for 20 minutes 4 times per day for 7 days. Upon completion of each treatment the enamel half-slabs were paired with their respective demineralized control half-slabs, embedded, sectioned, and subjected to microradiography and densitometric image analysis, for measurement of the level of remineralization. The mean area of remineralization (∆Zd-∆Zr) and mean percent remineralization (%R) in those chewing xylitol gum containing funoran and calcium hydrogenphosphate were significantly higher than the corresponding values for xylitol gum, sugar gum and gum base. Chewing xylitol gum containing funoran and calcium hydrogenphosphate has a significant effect on the remineralization of initial caries-like lesions of the teeth. ing remineralization (Imfeld, 1999; Dawes and Kubieniec, 2004). Chewing gum has the potential for being an effective vehicle for delivering therapeutic agents to the teeth because they allow prolonged contact between the agent and the teeth with minimal effort by the patient. A previous paper (Edgar and Geddes, 1990) reviewed studies that evaluated the effectiveness of a number of potential anticarious agents in chewing gum. Among the agents that have received considerable attention was calcium hydrogenphosphate, which was assessed for its effects on elevating the calcium and phosphate INTRODUCTION Chewing gum is known to have a beneficial effect on oral health and may be a useful adjunct to common oral hygiene. Gum chewing is a potent stimulant of salivary flow and calcium and phosphate levels, limiting demineralization and enhancSOUTHEAST ASIAN J TROP MED PUBLIC HEALTH 346 Vol 40 No. 2 March 2009 concentrations in the saliva (Pickel and Bilotti, 1965). The sugar alcohol xylitol has been claimed to have an effect on reducing dental caries (Kovari et al, 2003). The mechanisms of action include enhanced remineralization of the enamel by acting as a carrier for calcium ions into white spot lesions (Miake et al, 2003). The chewing of this kind of sugarfree gum after meals and snacks has been shown to promote remineralization (Imfeld, 1999). Funoran, a high molecular weight sulfated polysaccharide extracted from the red seaweed Gloiopeltis furcata has been demonstrated to inhibit cariogenic and periodontopathic bacteria, and thereby contribute to the prevention of dental caries and periodontal disease (Saeki, 1994; Saeki et al, 1996 a,b). Chewing gum containing funoran and calcium hydrogenphosphate has a remarkable ability to enhance remineralization throughout all layers in initial caries-like enamel lesions in vitro (Takahashi et al, 2001). The purpose of the present study was to assess the remineralization effect of xylitol chewing gum containing funoran and calcium hydrogenphosphate on enamel subsurface lesions in a human in situ model in Thailand. The results from this study should provide information regarding the remineralization potential of these gum additives. MATERIALS AND METHODS