Remineralization Therapy Using Fluoride Releasing Materials on Proximal Carious Models

Objectives: To compare the in-situ remineralization effects associated with the use of conventional glass-ionomer (GI) or resin-modified glass-ionomer (RMGI) on proximal incipient carious lesions of permanent molars at 1, 4, and 8 weeks. Methods: The proximal surfaces of ten extracted human permanent molars were sectioned into 14 slabs (seven from each surface) upon which artificial carious lesions were created, then divided into 5 experimental groups: extraoral control, intraoral control, GI (Fuji VII; GC Corp., Tokyo, Japan), RMGI(Pro Seal; Reliance Orthodontic Products, Itasca, IL, USA) and intraoral-arch control. Five volunteers wore custom made intraoral palatal devices containing 22 slabs, 11 slabs per side-arranged to reproduce proximal contact, from two teeth. The specimens were exposed extraorally to a 20% sucrose solution 5x per day. Each volunteer used a fluoride containing dentifrice and exposed the palatal device to the dentifrice slurry for 1 minute, 2x per day. One slab was collected from each group per volunteer after the first, fourth, and eighth weeks. Each piece was cross-sectioned and analyzed under polarized light microscope and the lesion area calculated. Results: Both GI and RMGI were associated with significantly less carious lesion areas compared to control at week 1 and 4 (p<0.05). There was no significant difference between lesion area under GI and RMGI at weeks 1 and 8, while at week 4, GI yielded significantly lesser lesion area than RMGI (p<0.05) as compared to controls. Conclusions: After 8 weeks, glass-ionomer yielded a higher overall reduction of lesion area than resin-modified glass-ionomer compared to control.