The process of dental decay is a dynamic one involving episodes of demineralization and remineralization, and may be prevented by the proper use of fluoride. The overall objectives are to increase our understanding of demineralization and remineralization processes in order to develop clinically applicable remineralization fluids and to optimize use of existing preventive agents. The mechanisms of action of fluoride which are the primary focus of this grant are the inhibition of demineralization and the enhancement of remineralization. These two mechanisms will be investigated both in vitro and in vivo using enamel surfaces.
The specific aims are to test the hypothesis that acidic remineralizing fluids are more effective than neutral fluids on either surface softened or subsurface lesions; to test whether these remineralized lesions will be more resistant to subsequent acid attacks; to use in vitro pH cycling to test the ability of remineralizing fluids to prevent, arrest, and/or repair lesions; and to use an intraoral system to test the ability of remineralizing agents to enhance the ability of saliva to prevent, arrest, and/or repair lesions. The remineralization experiments will be conducted under relatively constant ion composition and will be followed kinetically. The amount, site and type of remineralization will be determined by polarized light microscopy and quantitative microradiography on the single sections. Both SEM with energy dispersive analysis nad x-ray diffraction of the lesion mineral will be used to evaluate the nature of the remineralized lesion, the size of the crystals and gross morphology. The episodic nature of dental caries will be studied using a pH cycling model in vitro and an intra-oral model in vivo. The in vivo experiments will rely on saliva as the main remineralizing agent, while test fluids will be used to """"""""prime"""""""" the hard tissue and enhance the effectiveness of saliva. Thus, techniques for prevention and repair of enamel caries will be developed, tested and made clinically applicable.

Agency
National Institute of Health (NIH)
Institute
National Institute of Dental & Craniofacial Research (NIDCR)
Type
Research Project (R01)
Project #
5R01DE004486-12
Application #
3219075
Study Section
Oral Biology and Medicine Subcommittee 1 (OBM)
Project Start
1978-07-01
Project End
1994-06-30
Budget Start
1992-07-01
Budget End
1994-06-30
Support Year
12
Fiscal Year
1992
Total Cost
Indirect Cost
Name
University of Iowa
Department
Type
Schools of Dentistry
DUNS #
041294109
City
Iowa City
State
IA
Country
United States
Zip Code
52242
Zero, D T (1995) In situ caries models. Adv Dent Res 9:214-30;discussion 231-4
Wefel, J S (1990) Effects of fluoride on caries development and progression using intra-oral models. J Dent Res 69 Spec No:626-33;discussion 634-6
Wefel, J S; Harless, J D (1987) The use of saturated DCPD in remineralization of artificial caries lesions in vitro. J Dent Res 66:1640-3
Wefel, J S; Maharry, G J; Jensen, M E et al. (1987) Development of an intra-oral single-section remineralization model. J Dent Res 66:1485-9