The Logan-Beaudesert region has one of the highest prevalences of early childhood caries (ECC) in the state of Queensland in Australia. Current public services management largely focuses on restorative and surgical treatment of young children under general anaesthesia with minimal emphasis placed on prevention. The aim of this research was to investigate preventive strategies for ECC that are suitable for this high risk, socially disadvantaged community.
The studies were designed as a series of prospective longitudinal investigations aimed at examining caries risk variables, and randomised clinical trials to test the effectiveness of: i) home visits compared with telephone contacts, ii) therapeutic agents to prevent ECC. A total of 1017 mother-child pairs were recruited at birth, and randomly assigned in sequential blocks to have either home visits or telephone contacts at 6, 12, 18 and 30 months. In addition, all children were examined in the community dental clinic at 24 and 36 months.
At recruitment the children were randomised into one of three groups:
(i) Study controls (SC): Toothbrushing twice daily with 400ppm fluoride toothpaste (0.304 percent monosodium fluorophosphate (MPP)) toothpaste
(ii) Chlorhexidine gel group (CHX): Toothbrushing twice daily with 0.304 percent fluoride toothpaste plus once-daily application of 0.12 percent CHX gel (Curasept, Curadent, Sarano, Switzerland)
(iii) CPP-ACP cream group (CPP-ACP): Toothbrushing twice daily with 0.304 percent fluoride toothpaste plus once-daily application of 10 percent CPP-ACP (Tooth Mousse, GC Corp, Tokyo, Japan)
At the home visits, dental examinations were conducted and microbiological samples were taken, followed by validated questionnaires on social, medical, dental, feeding and oral hygiene habits. Toothbrushing instruction and general advice was given to the mothers. In the telephone contact group of children, the same questionnaires, toothbrushing instruction and general advice were given to the mothers over the telephone. At the 24 and 36 month visits, all children were examined by one of 10 operators blinded to study participation. The teeth were checked for cavitations and white spots lesions. All mothers also received a dental examination and had swabs of the teeth taken at recruitment and 24 months. Mutans streptococci (MS) and lactobacilli (LB) counts were determined using the caries risk test CRT® Bacteria Ivoclar, Melbourne Australia. Dropout at 24 months was 30 percent and a further 12 percent by 36 months. An inability to contact or relocation beyond a reasonable distance was the main reason for dropout.
The investigations on the group of children who did not use the therapeutic agents provided unique longitudinal information related to colonisation of MS and LB. These results have provided clear and prospective evidence that acquisition of MS can occur before tooth eruption, and that the age of approximately seven months is a critical time for colonisation of cariogenic bacteria. The studies comparing two preventive approaches have demonstrated that home visits and telephone contacts conducted six monthly from birth can reduce ECC to between only two and seven percent from approximately 23 percent in the community. The randomised controlled trial investigating two therapeutic agents showed that the preventive effects largely stemmed from toothbrushing with low-dose children’s toothpaste, and that the additional use of CPP-ACP and CHX did not produce enhanced preventive benefits. In the case-control longitudinal investigations comparing children who developed their first carious lesions by 30 and 36 months, it was found that most children who developed caries at the earlier age were colonised with MS before 18 months, and were more likely to have enamel hypoplasia compared with those who developed caries later.
Several recommendations for prevention can be drawn from the results of the investigations: Firstly, prevention of ECC should be focused on reduction/ elimination of MS in the mouths of infants. The studies showed that MS colonisation is associated with lack of maternal education and poor maternal oral health, hence we recommend maternal education should begin at the antenatal stage to reduce risk of transmission of cariogenic bacteria. Secondly, as personalised maternal education conducted through home visits and telephone calls are highly efficacious at reducing caries, these methods are recommended for high caries risk communities. Thirdly, the results have consistently shown that twice daily toothbrushing is effective in preventing ECC, thus preventive programs are recommended to focus on this method. Fourthly, as enamel hypoplasia is identified as a major risk in children who developed caries, we recommend that all children receive dental examinations as soon as the teeth erupt to ensure early detection of enamel defects.
Future research may help identify novel and safe therapeutic agents and techniques that can block the colonisation of bacteria. However, as ECC is a multifactorial disease, prevention is likely to be most successful using a multi-prong approach involving behavioural, oral hygiene and therapeutic agent strategies.