The use of sealants and fluoride varnish in preventing early childhood caries

Abstract

Early Childhood Caries (ECC) is a completely preventable disease but still affecting around half of the preschool children worldwide. ECC often results in pain and infections, which significantly depreciate the children’s quality of life and overall wellbeing. The susceptibility of dental caries varies among children and teeth, and more target-specific and cost-effective caries-preventive measures are essential to combat the problem.

Systematic reviews and meta-analyses conducted in this thesis identified children with existing caries, poor oral hygiene and lower parental education attainment being more susceptible to future caries increment in their primary dentition. The consequence of ECC can be profound and lasting as children with ECC were shown to be 3 times more likely to develop caries in their mixed and permanent dentitions.

Among all primary teeth, the primary second molars (PSMs) have the longest service life for around 10 years. However, they are very vulnerable to caries as their occlusal fissures favour plaque accumulation. A meta-evaluation was performed as part of the thesis to evaluate different fissure sealants and preventive interventions to prevent occlusal caries in molars. Resin-based sealant (RBS) was found to be an effective and cost-saving preventive measure for permanent molars, but a clinically- and cost-effective treatment for the primary molars among preschool children is yet to be identified.

A randomised controlled trial was conducted to compare the clinical efficacies of 5% sodium fluoride varnish (NaFV) and glass-ionomer sealant (GIS) in preventing occlusal caries at PSMs. The cost effectiveness, children behaviours and acceptance towards these two preventive interventions were also evaluated. A total of 736 children were recruited from 18 kindergartens and randomised into either Group 1- receiving NaFV quarterly, or Group 2 - single placement of GIS at baseline. Interventions were performed on 1431 and 1264 PSMs, respectively. The primary outcome was the prevalence of dentinal caries developed at the occlusal surfaces of PSMs over time. By 18 months, 542 children with 1664 PSMs were reviewed. Despite a low GIS retention rate of 5.2% by 18 months, only 12.1% of PSM in GIS group developed dentinal occlusal caries. No significant difference was identified when compared to the proportion of occlusal dentinal decay among PSMs in the NaFV group (15.2%). Regression analysis with GEE revealed that only household income, baseline caries dft scores and plaque levels had a significant influence in the caries progression.

Further cost minimisation analysis suggested that single-placement of GIS is more cost-effective than quarterly-applied NaFV in prevention of occlusal caries. The children’s behaviours changed markedly within and between groups. Bivariate analyses at the 3 review timepoints consistently identified the child past anxiety and cooperation levels being the sole factors influencing their behaviours and cooperation towards upcoming dental examination and preventive treatments.

Quarterly-applied NaFV and single-placement of GIS demonstrated similar clinical efficacies in occlusal caries prevention among preschool children. However, GIS had a lower direct cost and thus being more cost-effective. Further research is required to forage a clinically- and cost-effective treatment to prevent occlusal caries among preschool children, and enhance children’s cooperation and behaviours.