**13. Discussion**

The use of intraoral photographs for caries determination in orthodontic patients is a wellaccepted method. Standardized photographs taken before and after appliance placement are available readily as a standard procedure in orthodontic care. Color photography as a means of recording prevalence of enamel opacity is a powerful method (Ellwood, 1993). Studies have shown that assessment of enamel demineralization from color images appears to be more reproducible than direct clinical observation utilizing only the naked eye (Benson *et al.,* 1998). Moreover, photographic records provide an efficient means to capture the appearance of enamel and provide a permanent record at a given time point. It allows an examiner, therefore, to assess the caries experience of a patient blindly and randomly. Based on pre- and post-

White-Spot Lesions in Orthodontics: Incidence and Prevention 329

In that there was zero demineralization measured with the CLSM but some degree of fluorescence loss found with the QLF raises questions. In spite having the specimens brushed daily, for the most part the fluoride varnish remained unexpectedly on the tooth surface throughout the experiment and had to be removed with a plastic scaler at the end of the experiment. Therefore, its mechanism of action must be considered. In addition to the anti-cariogenic properties of fluoride as rationale for use, the fluoride may not have been the only mechanism of action in this *in vitro* experiment in that the varnish formed a physical

In this study, the Aegis-Ortho group and the MI Paste group showed less demineralization numerically than the control group for both the CLSM and QLF test, though neither had statistical significance. Thus, both Aegis-Ortho and MI Paste were not different from the control group. The similar numerical levels of effectiveness for Aegis-Ortho and MI Paste are not surprising, given their similar mode of action. In analyzing these two treatments, the obvious disadvantage for the MI Paste group is that it requires daily application, whereas

While the results of this study help us better understand the prevention potential of these products, *in vitro* experimental conditions cannot encapsulate all the complexities of a living

The ultimate answer on efficacy of these products has to come from well-designed controlled clinical trials. An *in vivo* randomized controlled trial study that employs proven methods for clinical evaluation of incipient lesions around brackets and also includes the patient compliance factor would provide the highest level of evidence with respect to the

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

Adriens ML, Dermaut LR, Verbeeck RM: The use of Fluor Protector, a fluoride varnish as a prevention method under orthodontic bands. Eur J Orthod 1990;12:316–9. Aimutis WR. Bioactive properties of milk proteins with particular focus on anticariogenesis.

Al-Khateeb S, Forsberg CM, de Josselin de Jong E, Angmar-Mansson B. A longitudinal laser

Al-Khateeb S, Exterkate RA, de Josselin de Jong E, Angmar-Månsson B, ten Cate JM Light-

fluorescence study of white spot lesions in orthodontic patients. Am J Orthod

induced fluorescence studies on dehydration of incipient enamel lesions. Caries

demineralization next to orthodontic brackets exposed to cariogenic conditions.

the ACP in Aegis-Ortho simply resides in the bracket bonding cement.

barrier to the acid challenge.

oral cariogenic environment.

**14. Conclusions** 

**15. References** 

preventive treatment modalities discussed.

J Nutr 2004;134:989–95.

Res. 2002 ;36:25-30.

Dentofacial Orthop 1998;113:595-602.

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 the acid attacks.

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

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 requires zero patient compliance.

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 orthodontic brackets with both CLSM and QLF.

In that there was zero demineralization measured with the CLSM but some degree of fluorescence loss found with the QLF raises questions. In spite having the specimens brushed daily, for the most part the fluoride varnish remained unexpectedly on the tooth surface throughout the experiment and had to be removed with a plastic scaler at the end of the experiment. Therefore, its mechanism of action must be considered. In addition to the anti-cariogenic properties of fluoride as rationale for use, the fluoride may not have been the only mechanism of action in this *in vitro* experiment in that the varnish formed a physical barrier to the acid challenge.

In this study, the Aegis-Ortho group and the MI Paste group showed less demineralization numerically than the control group for both the CLSM and QLF test, though neither had statistical significance. Thus, both Aegis-Ortho and MI Paste were not different from the control group. The similar numerical levels of effectiveness for Aegis-Ortho and MI Paste are not surprising, given their similar mode of action. In analyzing these two treatments, the obvious disadvantage for the MI Paste group is that it requires daily application, whereas the ACP in Aegis-Ortho simply resides in the bracket bonding cement.

While the results of this study help us better understand the prevention potential of these products, *in vitro* experimental conditions cannot encapsulate all the complexities of a living oral cariogenic environment.

The ultimate answer on efficacy of these products has to come from well-designed controlled clinical trials. An *in vivo* randomized controlled trial study that employs proven methods for clinical evaluation of incipient lesions around brackets and also includes the patient compliance factor would provide the highest level of evidence with respect to the preventive treatment modalities discussed.
