Fight Back! Proactively Addressing the Caries Process



THE CARIES PROCESS: A BRIEF OVERVIEW
There is a call to action for the profession of dental hygiene to employ the same standards in caries assessment, prevention, and subsequent management as we have in our treatment of periodontal disease. With the vast array of new and innovative products designed to assist both chairside and self-care protocols, we may emerge confident in having a strong impact on preventive intervention. The understanding of the mechanism of both the disease and its prevention is critical in counterbalancing the effects of today’s modern lifestyle. The need to intervene in the earliest stages of caries development cannot be overstated.
Dental caries is ranked as the most prevalent global disease even though we have witnessed a significant reduction during the past several decades. It is defined as a “dynamic disease process” which is caused by acids from bacterial metabolism diffusing into enamel and dentin creating dissolution of the tooth matrix.¹ The disease itself is an infectious, communicable disease that, if left untreated, can lead to pain, infection, tooth loss, and cellulitis of significant proportion. The psychological trauma associated with emergency-based care, although not measurable, can be debilitating. The process of dental caries is now well understood and is not the enigma it once was. However, there has been debate about whether early caries turns into eventual cavitation, and whether the different types of caries are both comparable and predictive.² The predominant bacteria implicated in the process is Streptococcus mutans, which is a gram-positive facultatively anerobic bacterium and an early colonizer in plaque biofilm. The microbe was initially isolated by J. Clarke in 1924. In addition to describing S mutans, he introduced the concept of microbial succession with different bacteria being dominant at different stages of the caries process.³ The clinical significance of this finding becomes essential in the development of a rational approach to risk assessment and the introduction of mechanisms of intervention.
Assessment, education, treatment, and prevention are all key components of addressing this disease successfully. One of the most critical factors is the recognition of the caries process being cyclic in nature and transitioning from demineralization to remineralization. This provides the dental hygienist with many opportunities to intervene in this dynamic process. Remineralization may be introduced with calcium and phosphate ions in conjunction with minimal amounts of fluoride facilitating a natural reparative process designed to rebuild stronger and less soluble structure than the original mineral.
The secondary challenge arises with the confrontation of making an evidence-based decision regarding product selection and treatment interventions both chairside as well as self-care recommendations. Fluoride selection falls into this category, given the immense and vast array of product availability. The ADA Council on Scientific Affairs has assisted our profession greatly by evaluating the collective body of scientific evidence as it pertains to the efficacy of professionally applied topical fluoride for caries prevention.⁴ The recommendations were published as a guide, rather than a requirement or regulatory statement, to assist the dental professional in the selection of an effective product. MedLine and the Cochrane Database of Systematic Reviews were both consulted for clinical studies and systematic reviews of professionally applied topical fluoride including gels, foams, and varnishes. The evidence was further graded and classified according to the strength of the recommendations as well as the highest category of evidence. There was clear, strong evidence to support the recommendation of fluoride varnish for prevention of caries in children and adolescents.⁵ New innovations in fluoride varnish have prompted a shift, with one of the most compelling rationales being the prolonged contact time that fluoride varnish provides.

Figure 1. 3M ESPE Preventive Measures Oral Health Risk Assessment and Management.	Figure 2. 3M ESPE Caries Risk Assessment Form.

The primary benefits of topical fluoride include inhibition of demineralization, enhancement of remineralization, and inhibition of bacterial enzymes. Low but slightly elevated levels of fluoride in saliva and plaque help prevent and reverse caries by inhibiting demineralization and enhancing remineralization.⁶ Remineralization may be further enhanced by providing calcium and phosphate in conjunction with minimal amounts of fluoride. This is due to the fact that fluoride acts as a catalyst and influences reaction rates with dissolution and transformation of various calcium phosphate mineral phases within tooth structure and reacts within the plaque adjacent to tooth surfaces.⁷ Continuous low levels of a slow release extended contact fluoride varnish containing both calcium and phosphate in a resin-modified glass ionomer applied to site-specific areas of demineralization provide further protection against demineralization and acid erosion.
Complimentary remineralization strategies may be employed in daily self-care regimens that are simple to incorporate into oral health practices. When the bacterial challenge is high and/or pH is lowered, there is a volatile oral environment that emerges. The added consideration of inadequate salivary flow to provide a buffering capacity further tips the scale towards demineralization. The remineralization process can be successfully integrated through the selection of remineralization toothpastes. Calcium and phosphate technologies such as the casein protein (CPP-ACP) as well as bioactive glasses containing NovaMin have been more recently developed to improve upon the earlier calcium phosphate products.
Recaldent (CPP-ACP) results in localization of CPP-ACP at the tooth surface by binding to dental plaque biofilm both in the microorganisms and in the extracellular matrix. Higher concentration fluoride toothpastes in combination with both calcium and phosphate have also been developed, producing favorable results when the dose response relationship was observed clinically.^8,9 NovaMin is a sodium calcium phosphosilicate glass that releases calcium and phosphate ions in an aqueous environment such as saliva. Sodium ions are the driving mechanism that exchange with hydrogen cations allowing both calcium and phosphate ions to be released. The result is a rapid and continuous release and deposition of a natural crystalline hydroxyl-carbonate apatite layer that is chemically and structurally the same as tooth mineral.^10,11
Nature also provides a “secret weapon” to fight back effectively against the caries process, and that product is xylitol. Xylitol is a 5 carbon sugar alcohol or polyol that cannot be metabolized by S mutans resulting in starvation or inability to assist in the demineralization or dissolution of tooth structure. The American Academy of Pediatric Dentistry has recognized the benefits of caries strategies implementing xylitol. Their recommendations were based on the overwhelming clinical data which underlines the caries reduction effects of xylitol. Their goal was to “assist oral healthcare professionals make informed decisions about the use of xylitol-based products in caries prevention.”¹² Studies suggest xylitol intake that consistently produces positive results ranged from 4 to 10 g per day divided into 3 to 7 consumption periods.^13-16

Figure 3. Post-treatment oral hygiene instruction.	Figure 4. Philips Sonicare FlexCare+ with UV Sanitizer.
Figure 5. Pretreatment demineralization on tooth No. 7.	Figure 6. Two weeks post-treatment VANISH XT (3M ESPE) on tooth No. 7.

CARIES RISK ASSESSMENT
Our standards for the practice of dental hygiene include risk assessment in order to facilitate patient-centered comprehensive care. Caries risk assessment and caries management by risk assessment exemplify a rapidly changing facet of the dental hygiene process.^17,18 The dental hygienist plays an integral role in risk assessment determining not only the development and implementation of preventive interventions but also the evaluation of successful treatment outcomes. Risk assessment is not intended to replace clinical judgment regarding individual patient circumstances but rather to aid in applying a comprehensive approach identifying treatment options to achieve and maintain oral health.
Today’s youth is bombarded with nutritional choices that serve to compromise the oral environment. Soft drinks with low pH and corresponding high sucrose levels as well as the advent of energy drinks provide an ideal environment for demineralization. Demineralization happens in an oral environment that falls below a pH of 5.5. The average soft drink or energy drink has a pH of 2.5 to 3.
There are a number of caries risk indicators as well as protective factors that need to be weighed in order to develop an effective individualized treatment plan (Figure 1). It becomes imperative that daily biofilm management incorporating effective plaque removal and remineralization strategies coupled with education all serve to provide optimal oral health.
The following case report has encompassed risk assessment as part of the assessment phase of the dental hygiene process of care. The product recommendations both for chairside as well as self-care selections are by no means a comprehensive listing of all available therapies. They have been selected to illustrate a patient specific treatment plan.

CASE REPORT
The patient was a 16-year-old female with a noncontributory medical history.
She had a history of routine preventive care and active orthodontic treatment for 3 years (debonded in 2007). Plaque had been noted on several appointments around orthodontic brackets while in active treatment, and she was prescribed home fluoride rinses in past which she was unable to tolerate. Several areas of interproximal incipient caries were noted in 2010; however oral hygiene status had been noted as improving over the last 6 to 12 months. Her care had also included radiographs taken every 6 to 12 months to assess incipient lesions, and in-office fluoride rinse was provided to her at 6 month intervals.

Oral Hygiene Status
Light plaque was visible along gingival margin in posterior areas; both lingual and buccal. Posterior interproximal bleeding on probing was localized to Nos. 2, 3, 14, 15, 18, and 31; all periodontal probing were depths < 3 mm.

Risk Assessment
High risk factors

• Caries restored in the past 3 years
• Frequent (> 3x/daily) between meal snacks of sugars/cooked starch
• Fixed orthodontic retainers on upper/lower arch.

Moderate risk factors

• Deep pits and fissures
• Interproximal enamel lesions/radiolucencies
• Other white spot lesions or occlusal discoloration.

Protective factors

• Lives/attends school in fluoridated community
• Uses over-the-counter fluoride dentifrice daily
• Salivary flow visually adequate (Figure 2).

Clinical Assessment Summary

• Permanent dentition; Nos. 1, 16, 17, and 32 unerupted
• Occlusal restorations present on teeth Nos. 2, 15, 18, and 31
• Pit and fissure sealants on Nos. 3, 14, 19 and 30
• Fixed lingual orthodontic retainers from teeth Nos. 7 to 10 and 22 to 27
• Demineralization noted on 6 mesiolabial, 7 labial and mesiolabial, 8 distolabial and mesiolabial, 9 distolabial, 22 labial, 23 mesiolabial, 24 distolabial and mesiolabial, 25 mesiolabial and distolabial, 26 mesiolabial, 29 buccal, 30 buccal
• Incipient lesions were noted clinically as well as supported by radiographic evidence on 7 mesial, 8 mesial and distal, 9 mesial and distal, 23 mesial, 24 mesial and distal, 25 mesial.

Patient Participation and Comments

• Infrequent flossing
• Difficulty tolerating fluoride rinses both chairside and with self-care
• Brushing twice a day and immediately following ingestion of any soft drinks with a manual toothbrush.

Discussion
Upon completion of risk assessment, the patient was placed in a high-risk category due to having caries restored in the past 3 years. There was also a number of moderate risk factors noted that would automatically place the patient in a high-risk category. The patient stated that she would consume soft drinks during the day and immediately following consumption would brush her teeth. The patient was provided with additional oral hygiene education informing her of the effects of acid erosion and the need to wait a minimum of 30 to 60 minutes before brushing her teeth19 (Figure 3) (Read and Watch video 1).
A power toothbrush was also recommended to meet the specific needs of the patient. One of the main reasons for the suggestion of a power toothbrush is supported by the numerous studies suggesting that a power toothbrush has been found to remove significantly more plaque than a manual toothbrush when used for one minute of brushing. The Philips Sonicare FlexCare+ with UV sanitizer was recommended for a number of reasons for this particular patient. The Philips Sonicare FlexCare+ has an integrated UV sanitizer that effectively kills up to 99% of selected microorganisms on selected toothbrush heads including S mutans, the predominant microorganism associated with the caries process.20 The patient reported infrequent and intermittent flossing. Through the patented technology of dynamic fluid force, Sonicare FlexCare+ has been studied resulting in conclusive evidence that it is able to remove interproximal biofilm beyond the reach of the bristles at a distance of 2 to 4 mm.²1 This will aid in delivering the remineralization toothpaste into a number of noted demineralized areas and interproximal incipient lesions (Figure 4).
The patient was placed on a 3-month interval with a recommended application of fluoride varnish (Figures 5 and 6) (Read and Watch video 2). Extended contact fluoride varnish was placed in site-specific noted areas of demineralization (Read and Watch video 3). In the interim, a remineralization toothpaste was recommended to be used twice daily containing calcium and phosphate as well as a therapeutic regiment of xylitol chewing gum taken after each meal and snack. A radiographic prescription was provided to assess radiolucent areas at regular intervals until the caries risk category had been diminished. Further salivary assessment and bacterial culture testing has also been recommended as well as subsequent caries evaluation using caries detection devices.

CONCLUSION
The preceding case report follows the assessment, dental hygiene diagnosis, and resulting implementation of a patient specific treatment plan. Evaluative outcomes will be measured, reassessed, and revised related to progress toward minimizing caries risk. There exists a powerful opportunity to support minimally invasive dentistry by embracing caries management by risk assessment. It’s time to fight back!

Acknowledgment
The author would like to acknowledge and express thanks to RDHU, the advanced dental hygiene continuing education centre, created by dental hygienists for dental hygienists for the provision of the dental studio for filming purposes and the DVD Quarterly of Dental Hygiene for their permission to use the video segments that accompany this article.

References

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12. American Academy of Pediatric Dentistry. Policy on the use of xylitol in caries prevention. aapd.org/media/policies_guidelines/ p_xylitol.pdf. Accessed January 3, 2011.
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14. Mäkinen KK, Hujoel PP, Bennett CA, et al. A descriptive report of the effects of a 16-month xylitol chewing-gum programme subsequent to a 40-month sucrose gum programme. Caries Res. 1998;32:107-112.
15. Milgrom P, Ly KA, Roberts MC, et al. Mutans streptococci dose response to xylitol chewing gum. J Dent Res. 2006;85:177-181.
16. Hujoel PP, Mäkinen KK, Bennett CA, et al. The optimum time to initiate habitual xylitol gum-chewing for obtaining long-term caries prevention. J Dent Res. 1999;78:797-803.
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19. Canadian Advisory Board on Dentin Hypersensitivity. Consensus-based recommendations for the diagnosis and management of dentin hypersensitivity. J Can Dent Assoc. 2003:69:221-228.
20. Hix J, Elliott N, de Jager M. In vitro evaluation of the Sonicare FlexCare integrated UV sanitizer. Philips Sonicare. Data on file, 2007.
21. Aspiras M, Elliott N, Nelson R, et al. In vitro evaluation of interproximal biofilm removal with power toothbrushes. Compend Contin Educ Dent. 2007;28(suppl 1):10-14.

Ms. Jones is an international speaker for the profession of dental hygiene and the owner of RDH CONNECTION, a consulting and training company dedicated to excellence in quality dental hygiene education. Having a career that has spanned more than 3 decades, Ms. Jones’ experience has encompassed clinical practice, education, international lecturing and she is published internationally. She has been appointed to serve on the advisory board for Dentistry Today and is a member of the Philips Sonicare North American professional education team. She is one of Dentistry Today’s 2011 Leaders in Dental Consulting and a Leader in Dental Education in North America. She can be reached via e-mail at jjones@rdhconnection.com or at rdhconnection.com.

Disclosure: Ms. Jones has no financial interest in any of the products referred to in the preceding article or in the accompanying video(s) and has received no compensation for writing the article, but has worked in the capacity of a professional educator for 3M ESPE and is a member of the Philips Sonicare North American Professional Education team.