**14. Conclusions**

328 Contemporary Approach to Dental Caries

orthodontic treatment photographic patient records, this study showed a high incidence of new WSLs (72.9%) in patients treated with comprehensive orthodontics, while the incidence of new cavitated lesions in this population was 2.3%. Gender, age and oral hygiene at start of treatment were not associated with lesion development, while a significant association was evidenced with treatment duration. Patients in treatment for less than 22 months developed on average three WSLs, while patients in treatment for 33 months or longer developed on average more than five lesions. Linear regression analysis suggested that as the duration of fixed appliances increased one month, 0.08 new WSLs were developed. The *in vitro* study sought to test four different treatments, which comprise much of the currently available therapies to prevent WSLs. The four experimental groups differed in their application, chemistry and physical properties. The Aegis-Ortho cement serves as a replacement for a typical bracket bonding cement. This ACP-containing material supposedly reduces the incidence of enamel demineralization with the release of calcium and phosphate ions – not only to reduce demineralization, but also to promote the remineralization of enamel. The fluoride varnish group received the same bonding cement as the control plus an application of Vanish, a popular fluoride varnish used for caries prevention. Unlike fluoride rinses that require patient compliance, the delivery of Vanish takes place in the dental chair and could be applied at the monthly orthodontic appointment. The CPP-ACP group teeth received an adjunctive daily application of MI Paste, whose chemical mechanism of action resembles that of the ACP cement. Instead of having ACP just residing in the bracket cement, the preventive protocol for MI Paste demands a daily application and, thus, a certain degree of patient compliance. MI Paste is claimed to have the ability to prevent WSLs during orthodontic treatment. Teeth in the final group received a light cured filled sealant as adjunctive treatment. Though it claims to offer some fluoride release, Pro-seal at its core functions as a protective physical barrier against

Compared with the control group, the Pro-seal group had a statistically significant difference in regard to both outcome measures (*i.e.,* lesion depth and fluorescence loss). The CLSM results indicated that there was no demineralization on any of the specimens in this group. Similarly, the QLF test demonstrated that teeth treated with Pro-seal had the least amount of fluorescence loss by far. The findings of this study confirmed that the Pro-seal functions as a protective barrier that is impermeable to the daily acid challenge. This impressive display of demineralization prevention under *in vitro* cariogenic conditions also

When interpreting the results of the current study, it is important to examine the experimental methods used. Obviously, the oral cavity of the typical teenager presents a much more dynamic and abrasive environment than those used in this *in vitro* study. However, it has been shown that Pro-seal sealant also displays physical properties when subjected to abrasion (Hu and Featherstone, 2005). Pro-seal prevented enamel demineralization convincingly and, thus, seems to be a reasonable treatment option that

The results from this study also indicated that teeth treated with the fluoride varnish had less enamel demineralization than the control and the ACP groups. Although it had a statistically significant difference in both lesion depth and fluorescence loss when compared to the control group, the difference was not nearly as dramatic in the QLF test. Currently, there are no other *in vitro* studies in the literature that examine fluoride varnish around

has been observed in other studies (Hu and Featherstone, 2005; Buren *et al.,* 2008).

the acid attacks.

requires zero patient compliance.

orthodontic brackets with both CLSM and QLF.

The incidence of WSLs in patients treated with comprehensive orthodontics was very high, suggesting that any preventive therapy provided appeared to be ineffective. This widespread problem poses an alarming concern and warrants significant attention from both patients and providers that should result in greatly increased emphasis on effective caries prevention. Results from this study suggest that both the lightcured filled sealer (Proseal) and the fluoride varnish (Vanish) have the potential to prevent enamel demineralization next to orthodontic brackets exposed to cariogenic conditions.
