Oral Hygiene and Decalcification in Orthodontic Treatment

Introduction to Malocclusion and Orthodontic Treatment

Malocclusions are believed to be the third most frequent oral health problem and are connected with a number of complications. Orthodontic therapy can often correct these problems or at least prevent them from progressing. It also carries some probability for damage to teeth and periodontal tissues. Oral hygiene is considered difficult to maintain during treatment, which can lead to plaque buildup and gingival irritation. Research has shown that orthodontic treatment encourages changes in the oral environment, including an increase in bacterial presence and changes in buffer capacity, pH acidity, and salivary flow rate. However, relatively little is known about periodontal irritation that results in occult blood being present in saliva and the acidity of dental plaque. It is imperative to recognize the changes in the oral environment in patients who undergo orthodontic treatment with fixed appliances. In cases involving long treatment durations, dentists are dedicated to protecting the patient's oral health (Lara-Carrillo, Montiel-Bastida, Sanchez-Perez, and Alanis-Tavira, n.d.).

Plaque Accumulation and Microbial Changes with Fixed Appliances

Patients who undergo orthodontic treatment with fixed appliances often face a challenging set of oral hygiene circumstances. Orthodontic bands, brackets, and wires obstruct brushing and flossing, and thus facilitate the buildup of plaque and endanger gingival health. It has been well documented that orthodontic treatment with fixed appliances brings about an increased risk of caries and gingivitis. A microbiological alteration following the placement of orthodontic appliances has been demonstrated in many studies. Growing numbers of Streptococcus mutans and lactobacilli after bonding of fixed appliances have been reported. Other studies have revealed statistically significant increases in periodontal pathogens such as spirochetes, motile rods, and other gram-negative organisms (Schatzle, Thomas, Sener, and Schmidlin, 2009).

Chronic Hyperplastic Gingivitis and Demineralization Risk

Orthodontic appliances hinder tooth cleaning and can promote the onset of chronic hyperplastic gingivitis (CHG). The precise aetiology of chronic hyperplastic gingivitis is still not fully understood, although plaque has been established as the main contributory factor. It has also been documented that certain individuals are more susceptible due to genetic and environmental factors. CHG can progress to periodontitis and the loss of tooth attachment over time. The concern in orthodontics is whether appliances accelerate the evolution from gingivitis to periodontitis. This is thought to occur because plaque accumulates between the brackets and bands and the gingival margins. Furthermore, plaque maintenance throughout fixed appliance orthodontic treatment has been identified as a significant aetiological factor in the progression of demineralization, in addition to chronic hyperplastic gingivitis. It is often suggested that the metals in orthodontic brackets and bands are cytotoxic and encourage localized inflammatory changes in the gingival tissues. This has been clinically apparent when orthodontic bands have been placed sub-gingivally (Gray and McIntyre, 2008).

Effective oral hygiene is particularly important for those undergoing orthodontic treatment. Fixed orthodontic appliances often prevent both successful tooth brushing and the mechanical cleaning action of mastication, which then leads to plaque buildup. Given the extended treatment times, emphasis must be placed on routine hygiene for the orthodontic patient, as well as professional tooth cleaning and home care instruction (Arici, Alkan, and Arici, 2007).

When teeth are banded for orthodontic therapy, metal is placed entirely around the tooth, creating a metal-enamel junction both occlusally and gingivally. These locations, particularly the gingival junction, are the primary areas of plaque accumulation. Following the placement of orthodontic bands and arch wires, there is a considerable increase in the facultative microbial population, comprising streptococci, lactobacilli, staphylococci, and yeast. Along with an increase in the microbial population, there is an associated rise in both extracellular and intracellular carbohydrate per milligram of plaque. This increase in carbohydrates promotes greater plaque persistence, reducing the effective washing of the tooth surface by saliva and thus diminishing salivary neutralization of acids, which results in more acidogenic plaque. Advances in the use of direct and indirect bonding of orthodontic brackets to teeth by resin systems have reduced the application of metal banding. This bonding method allows the dentist to attach the bracket to one surface of the tooth, thereby reducing the affected surface area. Improvements in gingival health and a reduced occurrence of decalcification have been observed when bonding is used. Nevertheless, even with direct bonding methods, the problem of demineralization is not entirely eliminated. The junction between the bonding resin and the enamel is a common site for plaque buildup and possible enamel demineralization. The resin used to secure the bracket leaves an irregular margin around the bracket, which affords oral micro-organisms a greater opportunity to attach and proliferate (Mattingly, Sauer, Yancey, and Arnold, 1983).

Iatrogenic demineralization of enamel during orthodontic treatment occurs in approximately fifty percent of all patients. These lesions are unattractive and often lead to premature termination of treatment, which is frustrating for both the dentist and the patient. The active equilibrium that exists between enamel demineralization and remineralization is influenced by several factors, including the frequency of refined carbohydrate consumption and the intake of carbonated soft drinks (Mattick, Mitchell, Chadwick, and Wright, 2001).

References

Arici, Selim, Alkan, Arzu, and Arici, Nursel. (2007). Comparison of different tooth brushing protocols in poor-tooth brushing orthodontic patients. European Journal of Orthodontics, 29, 488–492. doi:10.1093/ejo/cjm038.

Corbett, J. A., Brown, L. R., Keene, H. J., and Horton, I. M. (1981). Comparison of Streptococcus mutans concentrations in non-banded and banded orthodontic patients. Journal of Dental Research, 60, 1936.

Gray, Darren, and McIntyre, Grant. (2008). Does oral health promotion influence the oral hygiene and gingival health of patients undergoing fixed appliance orthodontic treatment? A systematic literature review. Journal of Orthodontics, 35, 262–269.

Gontijo, Leonardo, Cruz, Roberval de Almeida, Brandao, and Paulo, Roberto Gomes. (2007). Dental enamel around fixed orthodontic appliances after fluoride varnish application. Braz Dent J, 18(1), 49–53.

Katsue Miura, Karina, Yoko Ito, Izabel, Enoki, Carla, Elias, Ana Maria, and Matsumoto, Mirian Aiko Nakane. (2007). Anticariogenic effect of fluoride-releasing elastomers in orthodontic patients. Braz Oral Res, 21(3), 228–233.

Lara-Carrillo, Edith, Montiel-Bastida, Norma-Margarita, Sanchez-Perez, Leonor, and Alanis-Tavira, Jorge. (n.d.). Retrieved September 13, 2010, from

Mattick, C. R., Mitchell, L., Chadwick, S. M., and Wright, J. (2001). Fluoride-releasing elastomeric modules reduce decalcification: a randomized controlled trial. Journal of Orthodontics, 28, 217–219.

Mattingly, J. A., Sauer, G. J., Yancey, J. M., and Arnold, R. R. (1983). Enhancement of Streptococcus mutans colonization by direct bonded orthodontic appliances. Journal of Dental Research, 62(1209). DOI: 10.1177/00220345830620120601.

Schatzle, Marc, Thomas, Imfeld, Sener, Beatrice, and Schmidlin, Patrick R. (2009). In vitro tooth cleaning efficacy of manual toothbrushes around brackets. European Journal of Orthodontics, 31, 103–107. doi:10.1093/ejo/cjn070.