Positive Health Online

If Europe is following the trend that has been set in North America, then it is likely that we will become a society that is obsessed by appearance. With an increasing awareness of cosmetic and smile treatments, there will be no excuse to have anything less than a perfect smile. It's interesting to note that little is mentioned about the underlying factors that cause people to look for cosmetic dentistry. In most cases this is due to tooth decay leading to unsightly restorations, or early loss of teeth resulting in gaps, and poor tooth position which impact on smile. The key issue should be to prevent the tooth decay before it starts causing problems. In order to do this optimally, prevention should be started as early as possible.

What is so Special about Dentistry for Children?

Unlike any of the other dental specialties, a specific type of procedure does not define paediatric dentistry; it is defined by the age of the patients. Specialist paediatric dentists are trained to evaluate the growth and development of children from birth through to their adolescence. They treat all aspects of children's dental needs using highly specialized techniques and provide preventive advice. The treatment that these specialized dentists can provide includes not only managing any pathology associated with the dental hard and soft tissues, such as tooth decay and trauma to teeth and lips, but also to manage their patient's psychological needs. Paediatric dentists take into account a child's emotional development and any family circumstances that might affect their ability to comply with preventive advice and cope with receiving treatment. The other area that is included in the scope of specialized paediatric dentistry is the care of children with 'special needs'. These children include those with medical problems such as cardiac problems or cancer, children with physical disabilities such as cerebral palsy, and those with learning difficulties. To become a specialist in paediatric dentistry, several years of additional training are required after obtaining a general dental qualification.

There are several advantages that dentists have when working with children, depending upon the age of the child: there are two sets of teeth, children are still growing, and true primary prevention can be implemented before any dental diseases start.

Although paediatric dentistry covers all aspects of children's dentistry, in this article I would like to concentrate on one area of the speciality, tooth decay or as it is called clinically, dental caries. This is a unique infectious disease. It is the most common disease of childhood that occurs worldwide, and it if not treated will progress and cause problems. Accordingly, when it occurs, timely professional intervention is required. I would like to dispel the mistaken belief that drilling out a carious lesion and placing a restoration will eliminate the bacteria and thereby stop caries progression.

The Nature of the Caries Process

The caries process can be visualized as a balance between the pathological factors promoting loss of calcium and phosphate from the dental hard tissues (demineralization), and protective factors promoting the process whereby calcium and phosphate enter the dental hard tissues (remineralization). During any 24 hour period there will be times when the balance is level as well as being tipped in favour of either demineralization or remineralization. If the pathological factors tip the balance in favour of more demineralization than remineralization, then there will be caries progression. Cavity formation is the net result of too much demineralization.

Pathological Factors that Tip the Balance in Favour of De-mineralization:

1. Cariogenic bacteria are found in the complex biofilm which contains many kinds of bacteria called dental plaque. Those bacteria that produce acid, called acidogenic bacteria, must be considered to be risk for demineralization. The most common ones are Mutans streptococci and Lactobaccilli;[1]
2. Fermentable carbohydrates, including sucrose, glucose, fructose, lactose and even cooked starches, all of which can feed the acidogenic bacteria.[2] These bacteria are not fussy so, even 'healthy' fruit or milk can result in acid production which will contribute to the demineralization tip of the balance;
3. Saliva and its components are essential for the maintenance of oral health through the formation of the biofilm that covers the teeth and oral mucosa.[3] Any salivary dysfunction, for example reduced flow or increased viscosity, can result in a reduced protective capacity of the saliva.

Protective factors that Tip the Balance in Favour of Re-mineralization:

1. Saliva flow and saliva chemistry can facilitate remineralization. Saliva helps to flush away carbohydrates from plaque and buffer the acids produced by the bacterial plaque. The proteins and lipids in saliva help form the pellicle, the protein biofilm on the tooth surface that protects the tooth mineral by maintaining the calcium and phosphate at super-saturated levels, and it also has antibacterial proteins.[3] Saliva can act as a carrier for fluoride and other remineralizing agents that can then enter the plaque and alter the chemistry of the dental hard tissues;
2. Fluoride acts through two mechanisms: first it interferes with bacterial metabolism[4] and secondly, when it diffuses into the tooth, it binds to the calcium and phosphate, thus inhibiting demineralization.[5]
3. Raised levels of calcium and phosphate in saliva and on the tooth surface facilitates diffusion of these ions into the tooth and thus helps remineralization. There are several commercially available products to help encourage the remineralization process. They are gels which contain calcium and phosphate ions in appropriate concentrations with casein, a bovine milk protein. The purported mechanism for its action is that the casein binds to the enamel surface and holds the calcium and phosphate ions so that they are available to remineralize the tooth tissue;[6]
4. Antimicrobial therapy over and above that provided from the saliva and gingival crevicular fluid (fluid that leaks from the gum crevice at the neck of the teeth).[7]. A mouth rinse based on Chlorhexidine gluconate can effectively reduce Mutans streptococci levels in the plaque biofilm, but is less effective against Lactobacilli.[8] Xylitol, a non-cariogenic sweetener, has been shown to be more effective against Lactobacilli by interfering with bacterial adhesion and metabolism.[9]
5. Other techniques such as the use of fissure sealants,[10] and fluoride releasing dental materials[11] can be considered to help with tipping the caries balance in favour of remineralization.

Current Changes in the Management of Tooth Decay

A paradigm shift in the way dentists and other health care professionals approach prevention and management of dental caries is taking place away from the 'surgical' – drill and fill strategy to a 'medical' strategy. Management used to be based on either removal of the decay, by drilling and then filling the resultant cavity, or by extraction of the decayed tooth. Following extractions there may have been an additional intervention to manage the resulting gap. If prevention was considered, there were standard preventive packages which included the recommendation that the teeth should be brushed well and sugar consumption should be reduced. This preventive advice relied on patient cooperation and often required significant lifestyle changes that are at best difficult to implement and maintain, or at worst are ignored.

The new approach focuses on early (prenatal if possible) risk assessment of the mother, and implementation of appropriate therapeutic intervention including use of antimicrobials, early risk assessment of infants at 6 months of age and a reduction in the levels of caries-producing bacteria.

To help understand this approach, think of the mouth as containing a bacterial eco-system. If there is a high intake of carbohydrates this will encourage a carbohydrate-loving system that will produce acid, which will cause the balance to shift in favour of demineralization if any carbohydrates are consumed. However, if there is a more neutral eco-system; even if this is exposed to carbohydrates, it will not result in a demineralization cycle. For the same carbohydrate exposure to the carbohydrate-loving eco-system, demineralization will occur readily. So the preventive dietary alterations recommended when given preventive advice are to ensure that there will be the presence of a neutral bacterial eco-system in the mouth.

Management of the Caries Process

Use of the caries balance concept is applicable to individuals of all ages; the following steps are necessary for the optimal management of the caries process:

1. Early Detection of any Carious Lesions
   The earliest changes in the enamel are seen as white patch lesions.[12] These are due to the loss of mineral from the surface of the enamel, and as a result there is a change in optical properties of the enamel. Although a visual assessment is a good way to detect the earliest changes in enamel demineralization, caries does not only occur on the relatively smooth visible enamel surfaces which come into contact with the cheeks, lips and tongue. Caries occurs on the enamel surfaces in contact between adjacent teeth and in the pits and fissures on the biting surfaces of posterior teeth. To help diagnose carious lesions in these sites, radiographs are useful.[13] If there is a loss of mineral visible radiographically, the clinical depth of the carious lesion and the possibility of any bony changes around the root due to an infection in the root canal system may also be detected. There is a considerable amount of research into novel diagnostic techniques which do not involve ionizing radiation to detect early signs of mineral loss associated with carious lesions. The promising newer techniques involving laser fluorescence[14] and measuring changes in the electrical properties[15] of teeth are not yet widely available.
2. Assessment of caries risk factors which will determine the treatment plan
   Caries management by risk assessment (CAMBRA)[16] represents a paradigm shift in the management of dental decay. It treats dental caries as an infectious disease that is preventable and curable. The science supporting CAMBRA has been present for quite some time however, its clinical adoption has been slow.

The risk-assessment preventative dental package is tailored to the individual's needs. The preventative strategy must take into consideration a wide range of factors such as dietary advice, fluoride supplementation, the use of antimicrobials, aiding remineralisation, social and economic factors . Fissure sealing is one site specific preventative technique that is also of great value in managing high risk individuals.

In my specialist practice what I have been finding in recent years is that breakdown of family relationships and divorce is becoming an increasingly significant factor driving lifestyle, in particular, diet and consumption of sugar. The management of children with dental caries in these social situations can be very challenging for the whole of the dental team.

As a specialist, I see a large number of pre-school children with rampant tooth decay. These children have many decayed teeth, and the pattern of tooth decay is usually related to the tooth eruption sequence. In addition, I have noted that the posture during feeding or sleeping can influence the symmetry of the distribution of the carious lesions (Figure 1).

Figure 1. This shows a three year old child with rampant tooth decay.
Note the asymmetric distribution of the tooth decay affecting the child's upper left teeth.

In a typical case of rampant tooth decay presenting at three years of age, all the deciduous teeth will have erupted and the bite pattern will be established. There will be decay affecting the upper four incisors and the upper and lower first deciduous molars. The lower incisors are not affected at an early stage in the process, as they are protected by the tongue and the saliva from the salivary glands under the tongue.

At present, there is some controversy regarding the cause of rampant caries; on-demand breast or bottle feeding have been cited as key factors.[17] Regardless of the controversy, the asymmetric distribution of the carious lesions seems to be related to the child's feeding posture. If a mother breast feeds on-demand during the night and favours her left breast, the child will have more decay on the right side of their mouth, due to gravity pooling the breast milk. Similarly, in the case of older children and even adults who snack close to bed-time, even if the teeth are brushed meticulously, the sugar from the snack remains in the saliva and it is not unusual to find an asymmetric distribution of decay in these individuals. It seems that the effect of gravity on the saliva determines where the sugary saliva accumulates during sleep, and the caries process is then able to continue surrounded by carbohydrate containing saliva.

What Restorations are Available?

This is a substantial subject on which there are many opinions in relation to the best materials and techniques, but the old adage that the more solutions there are, the less likely there is to be an ideal solution, still holds true. The controversy about the use of dental amalgam still rages.[18] Several countries have now banned its use and the latest country, Denmark, has banned its use from January 2009 on environmental grounds. My personal thoughts are that there are alternative materials to amalgam that are more cosmetic and in some cases have therapeutic properties and these can be used effectively.

Figure 2a. This shows a four year old child with rampant tooth decay
and erosion before cosmetic treatment.

Figures 2a and 2b show the appearance of a four-year-old patient with rampant dental caries before and after cosmetic restorations were placed. Where optimal aesthetics are needed, composite materials can be bonded to deciduous teeth. In the cases where large areas of tooth tissue are missing, crowns can be used. The most common variety used on deciduous teeth are made from stainless steel, with no Nickel. Although these are not particularly aesthetic they last very well and usually do not have to be replaced. Cosmetic versions of these stainless steel crowns are also available.

Figure 2b. This shows the same child as seen if Figure 2a following cosmetic treatment
using bonded composite material to obtain a functional aesthetic dental appearance Figure 2b.
This shows the same child as seen if Figure 2a following cosmetic treatment using bonded composite
material to obtain a functional aesthetic dental appearance

Summary

I would like to reiterate that the overall goals in relation to dentistry for children are to facilitate optimal dental growth and development of a healthy, confident individual. To achieve this, specialist paediatric dentists help children to have good, positive experiences when they attend for regular check ups. They also ensure that they do not have any issues should they require any treatment.

Should children not develop a positive attitude towards maintaining good dental health and become fearful of visiting the dentist for check ups or treatment, these are likely to become those adults who seek cosmetic dentistry. Provided individuals have had positive dental experiences as children, they should have optimal dental health and a great smile.

References

1. A mixed-bacteria ecological approach to understanding the role of the oral bacteria in dental caries causation: an alternative to Streptococcus mutans and the specific-plaque hypothesis. Kleinberg I. Crit Rev Oral Biol Med. 13(2): 108-125. 2002.
2. The microbiology of dental caries. Hardie JM. Dent Update 9(4): 199-200, 202-4, 206-8. 1982.
3. Saliva the precious body fluid. DePaola, D P J. Am Dent Assoc 139, No suppl_2, 5S-10S. 2008.
4. Strategies to enhance the biological effects of fluoride on dental biofilms. Koo H.
Adv Dent Res 20(1): 17-21. 2008.
5. Community water fluoridation and caries prevention: a critical review. Pizzo G, Piscopo M R, Pizzo I,and Giuliana G. Clin Oral Investig. 11 (3): 189-93. 2007.
6. Remineralization of enamel subsurface lesions by casein phosphopeptide-stabilized calcium phosphate solutions. Reynolds EC. J Dent Res 76(9):1587-1595. 1997.
7. Salivary Antimicrobial Peptide Expression and Dental Caries Experience in Children
Tao R, Jurevic R J, Coulton K K et al. Antimicrobial Agents and Chemotherapy, 49(9): 3883-3888. 2005.
8. A two-year randomized clinical trial of chlorhexidine varnish on dental caries in Chinese preschool children. Du MQ, Tai BJ, Jiang H, Lo EC, Fan MW, Bian Z. J Dent Res., 85(6): 557-559. 2006.
9. Xylitol chewing gums and caries rates: A 40-month cohort study. Makinen KK, Benett CA, Hujoel PP, et al. J Dent Res.,7412:1904-1913. 1995.
10. The Effectiveness of Sealants in Managing Caries Lesions. Griffin SO, Oong W. Kohn B. et al. J Dent Res., 87(2): 169-174. 2008.
11. Evaluating the effects of fluoride-releasing dental materials on adjacent interproximal caries. Donly K J, Segura A, James M S, Wefel S, and Hogan B.A. J Am Dent Assoc., 130(6): 817-825. 1999.
12. Clinical diagnosis of precavitated carious lesions. Ismail A I. Community Dentistry and Oral Epidemiology 25(1): 13-23. 2006.
13. Bitewing and Digital Bitewing Radiography for Detection of Caries Lesions. A. Wenzel. J Dent Res., 83, No. suppl 1, C72-C75. 2004.
14. DIAGNOdent: An Optical Method for Caries Detection. Lussi1 A, Hibst R and Paulus R. J Dent Res., 83, No. Suppl. 1, C80-C83. 2004.
15. An in vitro comparison between two methods of electrical resistance measurement for occlusal caries detection. Kühnischa J, Heinrich-Weltzienb R, Tabatabaieb M, et al. Caries Res 40:104-111. 2006.
16 New Directions in Interorganizational Collaboration in Dentistry: The CAMBRA Coalition Model Douglas A. Young D A et al J Dent Educ. 71(5): 595-600. 2007.
17. On demand feeding controversy Breastfeeding and early childhood caries:
A critical review Ribeiro NME and Manoel AS. J Pediatr (Rio J). 80(5 Suppl):S199-S210. 2004.
18. A Scandinavian Tragedy: Jones D W. Br Dent J. 204: 233-234. 2008.