5.2 Our Model
5.2.2 Aligned Attention Layer
The approaches for caries prevention aim at maximizing the protective factors and remineralization while minimizing the factors that lead to demineralization. Four types of primary prevention have been identified. These are fluorides, fissure sealants, dietary counseling and oral hygiene96. Fluoridation of water supply remains the single most effective, equitable and efficient means of preventing dental caries.97 To ensure protection for areas with low natural fluoride, 1 part per million of fluoride is added to drinking water. However, not all rural areas have portable water supply. They may therefore be deprived of this protection.9 Other methods are available for fluoridation. The use of fluoride containing toothpaste is the most common method while other effective methods include the use of fluoride varnish, fluoride gel application and fluoride mouth rinse.98,97 Despite the beneficial role of fluoride in caries reduction, it does not eliminate it. So long as the intake of sugars continues, dental caries may still occur even in the presence of adequate fluoride.97
Fissure sealants are thin plastic substances painted over teeth as anti-cavity measure to seal out food particles and acid produced by bacteria.99 These resins are applied by dental personnel to the pit and fissure surfaces of posterior teeth. They are expensive and because there are differential tendencies for certain fissures to decay, sealants should be applied selectively to high risk patients and to permanent molars only within 2-3 years after tooth eruption.96
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Dietary counseling is also effective in inducing good dietary behaviour. Sucrose intake should be reduced and dentally safe substitutes used.96 Since dental caries is a bacterial disease in which diet, specifically ingestion of sugars is a major etiologic factor, caries control strategies aim to restrict exposure to sugars by substitution therapy. This involves replacing a harmful habit with a positive, more culturally acceptable practice.8 In the United States of America, caries control by the substitution therapy involves replacing the ingestion of fermentable sugars (primarily sucrose) with the non fermentable sugar substitutes (the polyols) in form of sorbitol or xylitol used to sweeten sugar-free chewing gum. It has been well-known for years that polyols do not promote caries and so relatively large amounts of these polyols (for example 7-14 grams per day), taken as xylitol sweetened gum three to five times a day for a minimum of five minutes after meals has no untoward side effects.8 The rationale for using chewing gum to control caries comes from the chewing action itself which stimulates saliva flow and the non cariogenic sugar substitutes used as sweeteners.8
In Denmark, the first clinical trial to determine the cariostatic effect of using a sorbitol containing chewing gum after meals was conducted among 312 children between 8 to 12 years of age from two schools. Students in one school were assigned to chew one piece of chewing gum after each meal for two years while children in the second school served as the control group and were not given gum to chew. The chewing sessions took place after breakfast and lunch in the schools. The children had oral examinations for dental caries and bitewing radiographs were taken at baseline, 1 year and 2 years. A statistically significant finding from the
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study showed that the average caries increment among the control group was 6.2 surfaces while that of the study group was 5.6 surfaces. This showed that the number of caries reversals was perceptibly greater in the group of children who were assigned to use chewing gum.100
Secondary prevention includes early diagnosis and treatment. The goal in caries management is to prevent new lesions from forming and to detect lesions very early in the process so they can be treated and arrested by non operative means.12 Based on this, the treatments given to children include teeth extraction, placement of dentures and orthodontic appliances, filling of cracks and the use of fluorides to remove plaques.101
Restorative treatment is a form of tertiary prevention. Treatment involves the use of minimally invasive restorative strategies on lesions that have cavitated surfaces and bacterial decay into the dentin.97 The restoration procedure should use the most minimally invasive approach possible to maintain the maximum amount of healthy tissue and structural integrity of the tooth.97
A novel caries prevention method is the use of probiotics.102 Probiotics are living micro-organisms that are isolated without modification from healthy individuals. They are primarily species of lactobacilli, bifidobacteria, and saccharomyces that act by replacing caries associated bacteria in the biofilm. They may also act systematically by producing bacteriocin such as hydrogen peroxide that may hamper and inhibit growth of a variety of bacteria. The drawback is that a daily dose of the probiotic is required as they do not permanently colonize the oral biofilm.102
43 2.3 Knowledge of pupils on dental caries
A major source of knowledge on oral hygiene habits is the parents, especially mothers. In a pilot study on knowledge and behaviors regarding early childhood caries among low income women in Florida, 101 participants were interviewed. A significant positive relationship was found between the frequency of mothers’ tooth brushing and how frequently their children’s teeth were brushed (r2=0.29; p=0.04). This shows that mothers’ oral hygiene habits determine to a large extent the oral hygiene habits of their children.103
Pupils’ knowledge on the causes of dental caries and practical skills for dietary choices and tooth brushing is also largely dependent on the quality of oral health education given to them by their teachers.104 A study was done in Tanzania on the impact of oral health education on primary school children before and after teachers training.104 Conventional and modified oral health education methods were used to teach the children. There were two study groups consisting of 200 first-grade pupils each, randomly chosen from ten schools. The conventional oral health education sessions held in very large classrooms comprising of about 37-184 pupils. The teachers used the Ministry of Education health education guide but no other teaching aids while the pupils remained passive throughout the lectures. The modified oral health education sessions held after the teachers training and were equally attended by large number of pupils as the conventional sessions. However, the teachers used the new teaching manual and other teaching aids. The pupils also had practical tooth brushing sessions where they were taught how to brush their teeth properly.104 It was reported that children who received modified oral health education had better knowledge of oral health, reported reduced consumption of sugary foods, had increased tooth brushing frequency and a slightly improved oral hygiene compared with those
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who had conventional oral health education, in whom it was found that they had some oral health knowledge but poor practices.104 From these findings, it can be said that the more knowledgeable pupils are as regards good oral hygiene habits such as correct brushing techniques especially after eating sugary snacks or drinks, the better they will be able to gain maximally from their education.
In another study, cross-sectional analytical study design was used to determine the prevalence of dental caries in first permanent molars of 9-12 year old primary school children from randomly selected primary schools in Sharfia area of Jeddah, Kingdom of Saudi Arabia. Of the 432 children sampled, those who received advice from their parents and teachers regarding cleaning their teeth after eating sugary food or drink had more sound first permanent molars (35%) and less caries (3%) compared to children who did not receive any advice (11%).55 This however was not a rural-urban comparative study and so one cannot infer if location had an influence on parents having time to advice their children on good oral hygiene practices.
On the contrary, a prevalence study done on dental caries among 12 year old children in urban and rural areas of Zimbabwe showed a general lack of knowledge on oral health issues by the participants even though overall, the urban children were more knowledgeable than rural children with no significant gender differences.69 Most children studied were knowledgeable about preventive measures such as regular cleaning of teeth, reduced consumption of sugary products and use of fluoridated tooth paste from information gotten either at home or in school.69