[Show abstract][Hide abstract] ABSTRACT: The objective of this study was to determine the ability of a calcium sodium phosphosilicate (NovaMin) particulate to occlude dentin tubules, and to characterize the nature of the occlusion through a number of in vitro studies.
Four experiments were designed to demonstrate the ability of NovaMin to 1) rapidly occlude tubules, 2) remain on the dentin surface in the face of acid challenges, and 3) form a biologically stable hydroxycarbonate apatite layer on the surface of dentin. Bovine dentin samples, polished to 1200 grit silicon and etched in 40% w/w o-phosphoric acid solution for 15 minutes to remove the smear layer, were employed in all four experiments. Four different experimental techniques were used to evaluate the effects of NovaMin and other marketed calcium-based products on tubule occlusion in 1) a single-treatment model, 2) a 10-day acid challenge cycling model to evaluate tubule occlusion, 3) a 10-day acid challenge cycling model to evaluate changes in surface hardness, and 4) a calcium-release model. Samples were assessed for tubule occlusion by scanning electron microscopy, surface mineralization by microhardness, and calcium release by inductively coupled mass spectroscopy.
For the single-treatment model, statistical analysis showed that all treatment groups had statistically fewer open tubules than the control group (untreated; p < 0.001), and that the NovaMin group occluded significantly more tubules than the Quell group (p < 0.001). For the cycling models, after a one-time brushing with the NovaMin (SootheRx) dentifrice, significantly fewer open tubules were visible compared to the untreated control (p < 0.001). After the 10-day cycle, there were few visible open tubules on the samples treated with SootheRx, a significant reduction when compared to the control samples (p < 0.001). The hardness of dentin treated with NovaMin during the 10-day cycle was significantly greater than sound and demineralized dentin (p < 0.001). The calcium-release model demonstrated NovaMin-based dentifrices released less calcium initially compared to the other treatment groups. After four hours, a higher release of calcium was observed that was sustained over 24 hours.
NovaMin adheres to an exposed dentin surface and reacts with it to form a mineralized layer. The layer formed is resistant to acid challenges and is mechanically strong. The continuous release of calcium over time is suggested to maintain the protective effects on dentin, and provide continual occlusion of the dentin tubules.
No preview · Article · Jan 2010 · The Journal of clinical dentistry
[Show abstract][Hide abstract] ABSTRACT: To evaluate the efficacy of a dentifrice containing calcium sodium phosphosilicate (NovaMin) study versus a placebo and a commercially-available SrCl2 containing dentifrice for the treatment of dentin hypersensitivity.
This was a 6-week, randomized, parallel-arm, double-blind clinical study. 71 subjects ranging in age from 21 to 56 years old completed the study. Evaporative and thermal stimuli were used to measure pain using a VAS scale. Measurements were obtained at baseline, 2 weeks and 6 weeks.
The placebo and the NovaMin groups showed a statistically significant decrease in sensitivity by both measures after 6 weeks (P < 0.05). The SrCl2 group showed a statistically significant decrease from baseline at the 2-week time point, but not at the 6-week time point for the evaporative stimulus. The percent reduction in sensitivity at 6 weeks for the NovaMin test group was 35% for air and 39% for cold water stimulus, versus 11% for air and 22% for cold water for the SrCl2 paste. The reductions for the placebo paste were 21% for the air stimulus and 18% for water. A cross tabulation measure of the reduction in sensitivity at each time point for all three treatments showed that the NovaMin product was more effective than either of the other products. For the air stimulus in the NovaMin group, 58% of subjects improved at each time point compared with 26% for the SrCl2 group and 20% for the placebo group. These results demonstrate that the NovaMin dentifrice was more effective at reducing sensitivity compared with a commercial dentifrice and placebo control.
No preview · Article · Sep 2008 · American journal of dentistry