Caries Interrupted

Dental caries prevention remains a primary objective of dental hygiene care. Part 1 of this update about effective approaches in the control of dental caries addressed methods aimed at disrupting bacterial pathogens. Here, we will continue by exploring perspectives on interrupting the carbohydrate contribution, followed by strategies that enhance protection against disease and strengthen teeth by aiding remineralization.

Addressing the carbohydrate contribution to dental caries has traditionally been difficult to implement. This is evident from the amount of dental caries seen in the general population. Changing dietary patterns can mean modifying lifestyles, and socioeconomic status may limit access to healthful foods.¹

Despite these challenges, patients should be advised that snacking more than three times a day between meals increases their risk for dental caries.² Healthful alternatives for snacking can be suggested, as patients may not be aware of the cariogenic potential of certain foods. Recording what they consume over a typical 3-day period may help patients discern patterns and find areas where they can make small but significant changes. For example, patients may substitute water or milk for soda or diet soda once a day. Patients can be advised to select sugar-free gum with xylitol, and to use it after snacking to stimulate salivary flow and promote oral clearance and neutralization of acids from cariogenic bacteria.

BUILD UP RESISTANCE

Products and therapies designed to strengthen the resistance of the teeth to acid attack include various forms and interapplications of fluoride and calcium-based products. Fluoride products for in-office application and home use are a well established component of caries prevention strategies. The effectiveness of home-use fluoride toothpastes, rinses, gels and tablets are dependent on patient compliance. Therefore, frequent professional applications of fluoride varnish, gels or foam are indicated for both children and adults at high risk for dental caries.³ Fluoride varnish has the advantage of being applied in a site-specific manner.

Diamine silver fluoride is a product that is available outside the United States for preventing and arresting early caries lesions and may in the future be available in this country. Clinical trials suggest that it may be twice as effective as fluoride varnish at caries prevention.⁴ When it is applied to demineralized enamel, the uptake leaves an area of stain. This may be acceptable on primary teeth soon to be exfoliated or to control root caries in posterior teeth of adults. Use of potassium iodide in conjunction with the silver fluoride treatment can prevent staining.⁵

REMINERALIZATION STRATEGIES FOR TEETH

Amorphous calcium phosphate (ACP) is generated by products that release calcium and phosphate ions when in contact with saliva. These precipitate as ACP on the tooth surface for uptake in carious lesions where the calcium and phosphate are released back out to remineralize as apatite crystal.⁶ Casein phosphopeptide-amorphous calcium phosphate (CPP-ACP), trade name Recaldent™, is a technology designed to stabilize ACP to deliver calcium and phosphate to the tooth for remineralization of subsurface lesions.⁷ Fluoride in plaque and saliva promotes tooth remineralization, as long as both calcium and phosphate are also present to form the fluorapatite crystal. Until the method of stabilizing calcium and phosphate with casein phosphopeptide (a milk protein) was developed recently there had been no mechanism to increase the levels of calcium and phosphate available for remineralization. CPP-ACP is taken up by dental biofilm so the minerals are available at the tooth surface for release during an acid challenge. Fluoride, calcium, and phosphate supersaturation of the biofilm promote remineralization rather than demineralization.⁷ CCP-ACP requires fluoride to be effective and is therefore not a substitute for fluoride therapy.

Arginine-bicarbonate/calcium carbonate products have been developed to address mineral loss in dentinal hypersensitivity and dental caries. This arginine complex composition binds to the tooth surface, allowing the calcium carbonate to slowly dissolve and release calcium, neutralizing acid production and remineralizing the tooth surface. The arginine complex is responsible for adhering the calcium carbonate particles to the dentin or enamel surface.

Calcium sodium phosphosilicate (Nova – Min^®) is a bioactive glass that was originally developed as a material for bone regeneration and for the treatment of dentin hypersensitivity.⁸ NovaMin reacts when exposed to body fluids and releases calcium, sodium, and phosphate ions to form the hydroxycarbonate apatite crystal and occlude dentinal tubules. Laboratory studies have demonstrated the remineralization potential of the hydroxycarbonate apatite crystals formed by NovaMin with and without fluoride.⁸

The decrease in salivary flow in patients with xerostomia causes them to lose the protective factors of saliva. Patients with this condition may especially benefit from technologies that provide increased levels of calcium and phosphate for remineralization. However, controlled delivery levels are important because too much calcium and phosphate may result in too much precipitate at once on the surface of the lesion, blocking diffusion of the ions into the deeper areas of the lesion.⁹

CONCLUSIONS

The present direction of caries prevention strategies is heavily weighted toward interventions that address the role of bacteria in dental caries and those that strengthen the tooth structure and promote remineralization. Affecting the intake of fermentable carbohydrates and compensating for lack of salivary protection are more difficult to address. Innovative technologies offer the possibility of developing new methods for addressing the multifactorial, complex nature of dental caries. These new therapies will need to be tested in randomized controlled trials to determine their efficacy and cost effectiveness at caries prevention. As active participants in the application of caries preventive strategies, dental hygienists will likely welcome new therapies designed to help to control a disease that impacts patients of all ages.

REFERENCES

1. Mobley C, Marshall TA, Milgrom P, Coldwell S. The contribution of dietary factors to dental caries and disparities in caries. Acad Pediatr. 2009;9(6):410-414.
2. Featherstone JD, Domejean-Orliaguet S, JensonL, Wolff M, Young DA. Caries risk assessment in practice for Age 6 through adult. J Calif Dent Assoc. 2007;35:703-713.
3. American Dental Association Council on Scientific Affairs. Professionally applied topical fluoride: evidence-based clinical recommendations. J Am Dent Assoc. 2006;137:1151-1159.
4. Llodra JC, Rodriguez A, Ferrer B, Menardia V, Ramos T, Morato M. Efficacy of silver diamine fluoride for caries reduction in primary teeth and first permanent molars of schoolchildren: 36- month clinical trial. J Dent Res. 2005;84:721-724.
5. Knight GM, McIntyre MM, Craig GG, et al. Differences between normal and remineralized dentine pretreated with silver fluoride and potassium iodide after an in vitro challenge by Streptococcus mutans. Austral Dent J. 2007;52:16-21.
6. Tung, MS, Eichmiller FC. Amorphous calcium phosphate for tooth mineralization. Compend contin Educ Dent. 2004;25:9-13.
7. Reynolds EC. Casein phosphopeptideamorphous calcium phosphate: the scientific evidence. Adv Dent Res. 2009;21:25-29.
8. Burwell AK, Litkowski LJ, Greenspan DC. Calcium sodium phosphosilicate (NovaMin^®): Remineralization potential. Adv Dent Res. 2009;21:35-39.
9. Wefel JS. NovaMin^®: Likely clinical success. Adv Dent Res. 2009;21:40-43.

From Dimensions of Dental Hygiene. May 2010; 8(5): 40, 53.