Calcium/Fluoride Efficacy in Remineralization/Prevention of Caries Progression

Objectives:  To assess the impact of MI Paste (MI), MI Paste Plus (P), SootheRX (S), and 1100ppm Fluoride (F) on remineralization and/or inhibition of caries progression.

Methods:  48 teeth were covered with varnish leaving enamel-windows 6mm mesio-distally, by 2mm occluso-cervically.  The teeth were placed in Ten Cate Demineralization solution (pH = 4.45) for 46 hours.  1/3 of the window areas were then covered.  The teeth were randomly divided into 4 groups and treated with 20% slurries of: MI, P, S, or F for 30 minutes 1x/day for 14 days.  ½ of the remaining uncovered windows were then covered.  The teeth were placed into demineralization solution (pH = 4.5) for 8 hours.  3 sections/window area (9/tooth) were then cut using a Silverstone Microtome.  Images of the sections were captured and measurements were made using polarized light microscopy.  One-way ANOVA with post-hoc Tukey-Kramer test was used to determine statistically significant differences in lesion depths between treatment groups at control, treatment, and final-demineralization (FD) areas.

Results:

   Lesion Depths (µm)

 

	Fluoride*	MI Paste**	MI Paste Plus	SootheRX***
Control	95.2	62.2	83.7	73.7
Treatment	89.1	68.5	82.7	71.1
FD	83.2	70.6	90.0	76.1

  Change in Depths (%)

 

Control-FD D	-12.6	13.5	7.5	3.3
Control-Treatment D	-6.4	10.1	-1.2	-3.5
Treatment-FD D	-6.6	3.1****	8.8	7.0

*          F was the only group with reductions at each interval

**        MI was the only group with increases at each interval

***      S showed the least overall increase in depth among the calcium-containing products

****    MI gave the best protection to further lesion progression among the calcium-containing products

Conclusions:  Fluoride showed the ability to remineralize, and offered the most protection against lesion progression.  SootheRX showed promise and may perform better in future studies with fluoride supplementation.  This study showed that fluoride is vital for demineralization protection.  Without it, available calcium and/or phosphate may be of little benefit.