2 Preventive and community dentistry

(Fig. 2.1) is a sugar-dependent infectious disease.¹ Acid is produced as a by-product of the metabolism of dietary carbohydrate by plaque bacteria, which results in a drop in pH at the tooth surface. In response, calcium and phosphate ions diffuse out of enamel, resulting in demineralization. This process is reversed when the pH rises again. Caries is therefore a dynamic process characterized by episodic demineralization and remineralization occurring over time. If destruction predominates, disintegration of the mineral component will occur, leading to cavitation.

The initial lesion is visible as a white spot. This appearance is due to demineralization of the prisms in a sub-surface layer, with the surface enamel remaining more mineralized. With continued acid attack the surface changes from being smooth to rough, and may become stained. As the lesion progresses, pitting and eventually cavitation occur. The carious process favours repair, as remineralized enamel concentrates fluoride and has larger crystals, with a ↓ surface area. Fissure caries often starts as two white spot lesions on opposing walls, which coalesce.

comprises demineralization followed by bacterial invasion, but differs from enamel caries in the production of secondary dentine and the proximity of the pulp. Once bacteria reach the ADJ, lateral spread occurs, undermining the overlying enamel.

Although it has been suggested that the mean time that lesions remain confined radiographically to the enamel is 3–4 years,² there is great individual variation and lesions may even regress.³ The rate of progression through dentine is unknown; however, it is likely to be faster than through enamel. Progression of fissure caries is usually rapid due to the morphology of the area. Rapid progression is especially common in primary molars, with progress from early dentine involvement to pulpal involvement in <1 year in some cases.

Under favourable conditions a lesion may become inactive and even regress. Clinically, arrested dentine caries has a hard or leathery consistency and is darker in colour than soft, yellow active decay. Arrested enamel caries can be stained dark-brown.

The sites on a tooth which are particularly prone to decay are those where plaque accumulation can occur unhindered, e.g. approximal enamel surfaces, cervical margins, and pits and fissures. Host factors, e.g. the volume and composition of the saliva, can also affect susceptibility.

Saliva acts as an intra-oral antacid, due to its alkali pH at high flow-rates and buffering capacity. Also:

An appreciation of the importance of saliva can be gained by examining a patient with a dry mouth.

Chewing sugar-free gum regularly after meals does appear to ↓ caries, but the reduction is small.

With gingival recession root dentine is exposed to carious attack. Rx requires, first, control of the aetiological factors and for most patients this involves dietary advice and OHI. Topical fluoride may aid remineralization and prevent new lesions developing. However, active lesions will require restoration with GI cement ( Root surface caries, p. 240).

Classically three main approaches are possible:

In practice this means dietary advice, fluoride, fissure sealing, and regular toothbrushing (which is also important in the prevention of periodontal disease). The relative value of these varies with the age of the individual.

Of equal importance with the prevention of new lesions is a preventive philosophy on the part of the dentist, so that early carious lesions are given the chance to arrest and a minimalistic approach is taken to the excision of caries where primary prevention has failed.

As caries can be arrested or even reversed, early diagnosis is important.

Remember: precavitated lesion—prevention

cavitated lesion—prevention and restoration.

Counsel the patient that if the lesion is not cavitated it has the potential to arrest. This makes the preventive advice very relevant to the patient, increasing the chance of that patient acting on the advice.

is relatively straightforward to diagnose. The chances of remineralization are ↑ as it is obvious, and accessible for cleaning. Restoration is indicated if prevention has failed and the lesion is cavitated, or if the tooth is sensitive or aesthetics poor.

is difficult to diagnose reliably, especially in the early stages. A sharp probe is of limited value as stickiness could be due to the morphology of the fissure. The anatomy of the area also tends to favour spread of the lesion, which often occurs rapidly. As fissure caries is less affected by fluoride and OH, f/s is preferable to watching and waiting. Occlusal caries evident on b/w X-rays should not always be excised. If the tooth is fissure-sealed or restored, check the margins very carefully, and if intact, monitoring the lesion radiographically is often justified initially. If marginal integrity not intact, investigate the area with a small round bur. The ‘cavity’ can be aborted if no caries found and the surface sealed.

Currently accepted practice:

If in doubt whether an approximal lesion has cavitated or not, fit an elastic orthodontic separator for 3–7 days so the surfaces can be visualized.

This subject has evoked considerable controversy, some arguing that regular attendance puts a patient more at risk of receiving replacement fillings, while others contend that regular and frequent check-ups are necessary to monitor prevention. In fact, it would appear that only a minority of the British public attend for 6-monthly check-ups. The available evidence suggests that there is no clear benefit for recall intervals of <1 year for healthy patients, although the at-risk patient often needs to be seen more frequently.⁶ In addition, as changing dentist ↑ the likelihood of replacement restorations the profession has to re-examine its criteria for replacement.

In the UK, guidance from the National Institute of Health and Care Excellence (NICE) recommends that dental recall intervals (‘oral health review’ intervals) should be determined by the needs of the individual patient based on a risk assessment of existing disease progressing or new disease developing. For adult patients this interval can be between 3 and 24 months and for children 3 and 12 months.⁵

A child’s first check-up should occur once the first teeth have erupted (i.e. usually between 6 months and 1 year of age).

The history of fluoride is covered well in other texts.⁷

(see Fig. 2.2)

The concentration of fluoride in enamel ↑ with ↑ fluoride content of water supply and ↑ towards the surface of enamel.

Enamel formed in the presence of fluoride has:

Discontinuation of systemic fluoride results in an ↑ in caries, ∴ pre-eruptive effects must be limited.

NB Newly erupted teeth derive the most benefit.

At higher pH fluoride is bound to protein in plaque. A drop in pH results in release of free ionic fluoride, which augments these actions.

NB Fluoride is more effective in ↓ smooth surface than pit and fissure caries.

Fluoride is present in all natural waters to some extent. Many simple chemicals are toxic when consumed in excess, and the same is true of fluoride.

Fluoride is absorbed rapidly mainly from the stomach. Peak blood levels occur 1h later. It is excreted via the kidneys, but traces are found in breast milk and saliva. The placenta only allows a small amount of fluoride to cross, therefore pre-natal fluoride is relatively ineffective.

(or mottling) occurs due to a long-term excessive consumption of fluoride. It is endemic in areas with a high level of fluoride occurring naturally in the water (Table 2.1). Clinically, it can vary from faint white opacities to severe pitting and discoloration. Histologically, it is caused by ↑ porosity in the outer third of the enamel.

(STD) Dose below which symptoms of toxicity are unlikely = 1mg/kg body weight.

(PLD) Lowest dose associated with a fatality. Patient should be hospitalized = 5mg/kg body weight.

(CLD) Survival unlikely = 32–64mg/kg body weight.

To reach the 5mg F/kg threshold (requiring hospitalization) a 5yr-old (about 19kg) would have to ingest 95 (1mg F) tablets, 63mL of 1500ppm toothpaste, or 7.6mL of 1.23% of APF gel.

<5mg F/kg body weight—large volume of milk. >5mg F/kg body weight—refer to hospital quickly for gastric lavage. If any delay give IV calcium gluconate and an emetic.

For advice about managing fluoride overdose contact National Poisons Information Service (0844 8920111).

A number of detailed systematic reviews have been conducted to investigate the efficacy and safety of fluoride, especially in the context of public water fluoridation schemes.⁸,⁹,¹⁰ These have all essentially come to the same conclusions:

Most important action of fluoride is to favour remineralization of the early carious lesion. Although fluoride incorporated within developing enamel results in a high local concentration following acid attack, the maximum benefit appears to be derived from frequent low-concentration topical administration.¹¹

To minimize the risk of mottling only one systemic measure should be used at a time.

at 1ppm (1mg F per litre) reduces caries by 50%. Main advantages are systemic and topical effect; no effort is required on the part of the individual; and the low cost. Yet despite this only 10% of the UK population has fluoridated water. In some countries school water has been fluoridated, but a concentration of 5ppm is required to offset the less frequent intake.

Regimen (mg F per day) depends upon drinking water content (see Table 2.2). This approach can be almost as effective as fluoridated water, but this requires good parental motivation. Unfortunately, compliance is generally poor, so benefit as a public health measure questionable.

with 2.5–7ppm F has been tried successfully.

is cheap and effective for rural communities in developing countries where water fluoridation is not feasible.

Overall, caries ↓ of 20–40%. Gels or foams applied in trays are still popular in some parts of the world, but without adequate suction the systemic dosage can be high and patients may not tolerate these well, Hence, their use in the UK is not extensive. Fluoride varnish (e.g. Duraphat^® 5% NaF) is useful for applying directly to individual lesions to aid arrest. Fluoride varnish has been shown to be effective at ↓ caries incidence in children, and regular application (2 times per year ↑ to 3–4 times per year where caries risk is ↑) is now advocated for all children over age 3 years deemed to be at risk of caries.¹ However, it should be applied carefully and sparingly, especially in young children as it contains 23 000ppm fluoride.

C/I in children <7yrs. The concentration depends upon the frequency of use: 0.2% fortnightly/weekly or 0.05% daily. Daily use is the most beneficial. Caries reductions of 16–50% have been reported with rinsing alone. The most widely used solution is sodium fluoride.

aid tooth cleaning, but, most importantly, provide fluoride. In the UK they contain abrasives (to a specified abrasivity standard), detergents, humectants, flavouring, binding agents, preservatives, and active agents, including:

For children considered to be at high risk of caries and who live in areas with water supplies containing <0.3ppm see Table 2.2.

May be prescribed for children deemed to be at risk of developing caries living in areas with less than optimal fluoride in the water supply. Compliance with self-administered fluoride supplements is often poor (i.e. parents often forget to administer them regularly).

Fluoridation of water still remains the most cost-effective method.

—based on concentrated milk proteins shows promise for both caries prevention and enamel remineralization.

has also shown some efficacy in preventing approximal caries.

A correlation has been found between the presence of Strep. mutans and caries. This is not surprising, because this organism is acidophilic, can synthesize acid rapidly from sugar, and produces a sticky extracellular polysaccharide which helps bind it to the tooth. However, caries can develop in the absence of Strep. mutans, and its presence does not inevitably lead to decay, e.g. root caries has been associated with Strep. salivarius and Actinomyces species. Lactobacillus species are also acidophilic and have been implicated in fissure caries. In addition, plaque prevents acid diffusing away from the enamel and hinders the neutralizing effect of salivary buffers.

To achieve more than a transitory effect, an antiseptic needs to be retained in the mouth. Chlorhexidine, a positively charged bactericidal and fungicidal antiseptic, is capable of this. It is attracted to the negatively charged proteins on the surface of teeth and oral mucosa and in saliva from where it gradually leaches out. It is available as a 0.2% mouthwash and a 1% gel which are cheaper over the counter than by prescription. Although the main application of chlorhexidine is in the management of gingivitis, it has been shown to be effective at ↓ caries when used regularly.¹⁷ While its widespread use for this purpose is not practical, it can be helpful in the management of disabled patients or those with ↓ salivary flow. Unwanted effects include staining, disturbance of taste, and parotid swelling (which is reversible). It is less effective in the presence of a large build-up of plaque and is inactivated by commercial toothpastes.

A variety of pre-brushing rinses are now available. Research suggests that these do have a small beneficial effect if used in conjunction with toothbrushing.¹⁸

As no vaccine is completely safe, the ethics of vaccinating against caries, an avoidable non-lethal disease, have been hotly debated.¹⁹ Yet, despite considerable research, efforts to produce a viable vaccine have been unsuccessful due to a number of problems:

Pits and fissures provide a sheltered niche for bacterial proliferation. Toothbrush bristles are too wide to fit into these areas, making complete plaque removal impossible. A fissure sealant (f/s) is a material that provides an impervious barrier to the fissure system to prevent the development of caries.

Several approaches to ↓ fissure caries have been tried:

In developed countries ↓ in caries seen in recent years has not been uniform for all tooth surfaces. Part of this ↓ is due to an ↑ availability of fluoride, leading to a greater reduction in approximal, rather than in pit and fissure caries. Therefore the need for a method of occlusal caries is even more pressing.

To be effective, need to be carefully applied to susceptible teeth. Most valuable in recently erupted (especially first) molars, but moisture control may be difficult. Therefore sealants should be monitored and replaced if lost. For maximum benefit, teeth should be sealed as soon as practicable after eruption and certainly within 2yrs. Guidelines for placement of f/s have been described.²⁰,²¹

f/s should be provided for 6s in:

Children with caries-free primary dentitions do not need routine f/s of 6s but should be monitored regularly. f/s of primary molars is not normally recommended.

For children who fulfil the earlier given criteria:

If there is doubt about a stained fissure, a b/w X-ray should be taken. If the lesion is in enamel, f/s and monitor clinically and radiographically. If in doubt, carry out an enamel biopsy. If the lesion extends to dentine place a PRR, providing the cavity does not extend to more than one-third of the occlusal surface, in which case a conventional restoration is required. Composite resin-based sealant retention: >85% after 1yr and >50% after 5yrs.²²

Discussion of the cost-effectiveness of sealants compared to restoration has been well aired over the years, which is surprising given that the end results are not comparable. Fissure sealants are highly effective, and reduce the incidence of dentine caries over 4 years by >50%.

Sealants can be classified by polymerization method (light- or self-cure), resin system (Bis-GMA or urethane diacrylate), colour (clear or tinted), and whether they are filled or unfilled. The choice is one of personal preference; however, it has been pointed out that coloured/opaque sealants are more readily obvious to the patient. The retention rates of the different types are similar: success depends upon maintaining an absolutely dry field during application.

GI sealants do release fluoride but have poorer retention than resin sealants. They are useful for high caries-risk children as a temporary sealant where adequate isolation for successful placement of resin-based sealants is not possible, e.g. partially erupted teeth/poor cooperation.

f/s should be monitored clinically and where appropriate, radiographically (b/w). Defective sealants should be replenished to maintain their marginal integrity.

Sugar—is used to refer to the mono- and disaccharide members of the carbohydrate family. Monosaccharides include glucose (dextrose or corn sugar), fructose (fruit sugar), galactose, and mannose. Disaccharides include lactose (in milk), maltose, and sucrose (cane or beet sugar). Polysaccharides (starch) are chains of glucose molecules and are not readily broken down by the oral flora. Dietary sugars have been classified as intrinsic when they are part of the cells in a food (vegetables and fruit) or extrinsic (milk sugar or, the real baddy, non-milk extrinsic sugar, e.g. table sugar). Both intrinsic and extrinsic sugars may cause decay, although non-milk extrinsic sugars are most cariogenic.

Sucrose is considered a major culprit—most commonly available sugar and able to facilitate production of extracellular polysaccharide in plaque. However, other sugars can also cause caries. E.g. frequent consumption of fruit-based drinks is known to be a key factor in the development of early childhood caries (ECC). In ↓ cariogenicity:

The frequency of sugary intakes and the interval between them, the total amount of sugar eaten in the diet, and the concentration of sugar and stickiness of a food have been shown to be important. The acidogenicity of a sugar-containing food can be modified by other items in the food or meal. Foods that stimulate salivary flow can speed the return of plaque pH to normal, e.g. cheese, sugar-free gum, salted peanuts.

In 1989 the COMA panel on Dietary Sugars and Human Disease reported that dental decay is positively associated with the frequency and amount of non-milk extrinsic sugar consumption. However, while sugar may contribute to the excess calorific intake which causes obesity and predisposes towards diabetes or coronary heart disease, there is no direct evidence linking sugar intake and these medical conditions.²⁴

This approach aims to take into account the modern habit of ‘snacking’ (also known as ‘grazing’):

Modification of only a restricted number of snack foods would probably be insufficient to have a significant effect.

Fig. 2.3 is a Stephan curve showing the pH drop that occurs after a sugary drink is consumed (shown by arrow). The dashed line indicates the critical pH; below this pH demineralization will occur. The shape of the curve is affected by a number of factors, including the type of sugary food, buffering potential of the saliva, and foods or drinks ingested after the sugary challenge.

(In Table 2.3 sweetness of sucrose = 1.)

The bulk sweeteners (largely polyols) can cause osmotic diarrhoea if consumed in large amounts and are therefore C/I in small children. However, it is probably wise to avoid all artificial sweeteners in pre-school children. The bulk sweeteners are isocalorific with sucrose, whereas the intense sweeteners are low calorie.

Diet can affect teeth:

To ↓ the time for which the teeth are at risk of demineralization and increase the potential remineralization period.

(i) high caries activity, (ii) unusual caries pattern, (iii) suspected dietary erosion.

Dietary advice should be tailored to the individual. This is most easily done after analysing the patient’s present eating pattern.

A consecutive 3- or 4-day analysis (including at least one weekend day) is the most widely used, with the patient recording the time, content, and quantity of food/drink consumed. In addition, toothbrushing and bedtime should be indicated. When the form is returned the entries should be checked with the patient.

should include an explanation of the effect of between-meals eating and sugary drinks. It must also be personal, practical, and positive! The suggestion that a child should select crisps when friends are buying sweets is more likely to be followed than total abstinence.

Some helpful hints:

Where the nutritional content of meals is inadequate, considerable tact is necessary. It may be possible to suggest that larger meals would reduce the temptation to eat snacks. For children who are ‘picky’ eaters snacks and sweets saved until the end of a meal can act as an encouragement to consume more food at mealtimes.

BUT remember that while cheese, peanuts, and crisps may constitute a safe snack in dental terms, they are all high in fat, and peanuts can be inhaled by small children. Also, ‘diet’ cola drinks are sugar-free, but can still cause erosion if large quantities are drunk.

Therefore, dental dietary advice should be given in the wider context of the general health of the individual, i.e. ↓ consumption of sugars and fats, and ↑ consumption of fibre-rich starchy foods, fresh fruit, and vegetables. Meals provide a better nutritional balance than snacks. Hence good eating/drinking at mealtimes and avoiding between meals snacking is healthy.

The objective of dental health education is to influence the attitude and behaviour of the individual to maintain oral health for life and prevent oral disease.

All health professionals. In practice, many patients relate better to advice from a hygienist or nurse.

It is important that the information given is factual and that different sources do not give conflicting advice. In order to unify the profession’s approach, the Health Education Authority has published a policy document²⁵ laying out four simple messages:

The way in which the advice is imparted is as important as its content. There are three main routes:

Because many patients find the dental surgery threatening, it may be better to choose a more neutral environment, e.g. a dental health or preventive unit. It is important that the information is given by someone the patient trusts and can relate to—this is not always the dentist! It is important also to have adequate time, as a hurried approach is of dubious value, and to choose words that the patient will understand.

The following approach has been used successfully:

Advice on preparing a talk on dental health education, setting up a preventive unit, or even a health programme can be obtained from Health Education England and more specifically your Local Education and Training Board (  http://www.hee.nhs.uk).

This is the main source of dental care for the majority of the population (whether NHS or private).

The Community Dental Service (CDS) was formed from the School Dental Service in 1974.

In 1989 the remit of the CDS was expanded (the guidance being updated in 1997) to cover the following:

have undergone significant changes in recent years. In many areas of the UK, they have been managerially amalgamated and are now known as Salaried Primary Dental Care Services. The range of services provided and patients accepted by such services can vary between localities and many no longer offer ‘safety-net’ services with more emphasis on care delivery to patients with disability, co-morbidity, and the elderly.

The role of the consultant service is to provide specialist advice and Rx, in addition to postgraduate training.

Two factors are important:

Because dentists have traditionally preferred to practise in leafy suburbs rather than poor inner city areas, these effects are often compounded.

Aside from the problems experienced by patients accessing NHS dental care, research has shown that the two main barriers to regular uptake of dental care by the general public are anxiety and cost.

This manifests as fear of pain or a particular procedure, or a feeling of vulnerability brought about by relinquishing control to the dentist in the sensitive area of the mouth. A patient’s first impressions are important as the reception they receive from staff and the environment in which they wait to be seen could either allay or reinforce their anxieties. The attitude of the dentist is also a significant factor: a ‘good’ dentist has a friendly, personal touch and explains what treatment is going to involve.

The perception still exists that dental Rx is expensive. Patients often find the way in which the charges are calculated confusing, but welcome an estimate of the costs prior to Rx.

Furthermore the pattern of attendance varies throughout life, with children now enjoying a visit to the dentist, but adolescents breaking the habit of regular attendance due to apathy &/or other pressures on their time. A return to the dentist may be triggered by pregnancy and desire to provide a good example to the children, or a need for urgent Rx and a fear of becoming edentulous.

A disabled person is someone with a physical or mental impairment which has a substantial and long-term adverse effect on his ability to carry out normal day-to-day activities.

Prevalence 3%. Classified into mild (IQ 50–70) and severe (IQ <50).

Many cases lack well-defined aetiology but there are some subgroups where cause/diagnosis is known:

Most common is cerebral palsy, which is the motor manifestation of cerebral damage. Many patients with cerebral palsy have normal IQs, but ↑ muscle tone and hyperactive reflexes can make Rx difficult. Many can be treated in general dental practice provided there is wheelchair access.

1% of children have either heart disease, bleeding disorders, diabetes, or kidney disease.

i.e. blindness, deafness (Fig. 2.4).

Many have more than one type of impairment.

The described groups are general disabilities. We also need to consider those that are orally disabled, i.e. have gross oral problem or deficit which necessitates special dental Rx (e.g. cleft lip &/or palate).

—this requires that:

It is difficult to generalize, but usually mental disability provides the biggest challenge. Difficulties ↑ in patients with >1 impairment.

Difficult to generalize. Patients with less severe disabilities can be treated in dental practice. Those with severe medical &/or mental impairments are probably best managed by a specialist who will have ↑ access to specialist facilities.

An initial plan should be formulated ignoring the disability. This can then be discussed with the patient, parent, or carer and modified for the individual. Where treatment needs are not urgent, it is advisable to start with OHI and prevention, then re-assess Rx requirements in the light of the response. For those patients for whom a satisfactory standard of OH is not possible, restorative Rx should aim to ↓ plaque accumulation. Excellent guidelines for the dental care of patients with disability and impairment have been produced by the British Society for Disability and Oral Health.²⁷

Those patients who can brush their own teeth should be encouraged to do so. Modification of toothbrush handles ( General management problems, p. 322) or purchase of an electric one may be helpful. Where patients are unable to brush their teeth, instruction should be given to their carer. The best method is to stand behind the patient and cradle the head with one arm, leaving the other free to brush. However, if possible this should be supplemented with regular professional cleaning. Chemical control of plaque with chlorhexidine may be helpful.

Greatest problems are posed by mentally impaired. Kind but firm restraint may be necessary—ideally, get the patient’s carer to help. A prop (e.g. McKesson rubber) may be needed. It is often easier to use intraligamentary LA technique. Sedation may help reduce the spontaneous movements of cerebral palsy. In some cases there is no alternative but to carry out examination and Rx under GA. In addition, for those patients who can tolerate out-patient Rx, but only a little at a time, it may be kinder to clear a backlog under GA, thus allowing concentration on prevention subsequently. However, this approach requires special facilities and no medical C/I.

Down syndrome, p. 755.

Dental Care Professionals (previously known as Professions Complementary to Dentistry) are a growth area in dentistry. With increasing demand for dental Rx and restraints on healthcare costs, the advantages of delegating more routine tasks to dental auxiliaries is obvious. There is also improved job satisfaction for all members of the dental team.

The GDC now register and regulate DCPs. This has resulted in a number of changes:

The following classes of DCP are recognized and regulated by the GDC:³⁰

The most recent survey showed that across almost all oral health indicators the trend for improvement seen in previous surveys has continued. However, for those with caries or periodontal problems disease can be extensive. In 2009, 94% of adults had at least 1 natural tooth. 75% of adults said they cleaned their teeth at least once a day (see Table 2.4).