Although the primary dentition has many important functions, due to lack of care prevalence of dental caries is high among preschool children. According to American Academy of Dentistry, the first visit to a dentist should be at one year of age and all children should have at least two routine visits to a dentist each year. In this study population a large percentage of children had never been to a dentist. Few children have visited a dentist to get treatment for a dental problem. This confirms that preschool children in Sri Lanka do not get adequate dental care. This is in stark contrast to other impressive health indices of Sri Lanka. Results of this study emphasize the importance of strengthening community based dental care services for preschool children in Sri Lanka.
Prevalence of dental caries showed a gradual increase with age to reach 68.8%, by the age of five years. This is high compared to western countries like England (6.8 -12%) and USA (11–53.1%). According to Kumarihamy et al. (2011) prevalence of dental caries among Sri Lankan children between 1–2 years was 32.19% and the mean deft was 2.01. In our study we included only children between two to five years, as we were studying only dentinal caries. Inclusion of early stages of caries (enamel caries) by Kumarihamy et al., explains the higher deft score observed by them compared to us. Results of Sri Lanka National Oral Health Survey 2002/03, also revealed a high prevalence of caries (65%) at 5 year of age. Absence of a programme to promote oral hygiene among preschool children and wrong feeding practices may be contributing for the high prevalence of caries observed. Unfortunately no action is taken up to now, to promote oral hygiene among preschool children in Sri Lanka
Although the SIC index for the total sample was 4.09, SIC index for children between 4 – 5 years was 5.84. WHO has a set a goal that globally the SIC index should be less than three, at 12 years of age, by year 2015
. Although no target is set for preschool children, SIC index for Sri Lankan preschool children is nearly double the expected figure. When enamel caries are also included actual figures will be much higher than this.
In contrast to the findings of the United States National Health and Nutrition Examination Survey 1999–2004
, boys in this population had a lower prevalence of dental caries and a low mean deft score than girls. High individual deft scores were also recorded from girls than from boys. As there is no gender discrimination against female children in Sri Lanka, there must be other factors responsible for this gender difference in dental caries. Effect of gender on prevalence of dental caries is probably an important area for future research.
Not only primary prevention of caries was unsatisfactory, but the care for carious teeth was also unsatisfactory. Majority of the carious teeth were left unattended, allowing children subjected to pain, discomfort and premature loss of primary teeth. Very low care index (1.55) proves this fact. Our findings are compatible with findings of Kumarihamy et al., which revealed 95% of carious teeth were left unattended. Primary teeth are not generally extracted unless they cause significant discomfort and pain, as they keep space for the permanent teeth. In this study we found some children who had multiple tooth extractions, which is a terrifying and fearful experience for a child of this age.
Previous studies have shown children living in poverty have higher prevalence of caries (14), but a clear association between family income and dental caries was not observed in this study. Though the highest income group had lowest prevalence of caries, the middle income group had higher prevalence than the lower income group. The discrepancy may due to other confounding factors like feeding practices. Children of mothers with a low educational level had high prevalence caries and children of mothers with highest educational level had lowest prevalence. However, a reverse pattern was observed in the middle educational categories.
This study was conducted in a district with higher socio-economic standards compared to most of the districts in the country (11). Therefore, it is reasonable to postulate the situation in other parts of the country may be worse than this. There are effective programmes in Sri Lanka for promoting breast feeding, family planning, immunization, growth monitoring and school dental hygiene, but there is no programme to promote oral hygiene in preschool children. Even at child welfare clinics no attention is paid to oral hygiene. According to this study and the study by Kumarihamy et al., the process of dental decay commences at a very early age. Any educational or interventional programme aimed at promoting oral hygiene should be introduced around latter part of infancy.
Brushing teeth twice a day is an important mode of preventing dental caries. Effective brushing will remove dental plaques, which is the first step in dental decay. Using a tooth paste containing fluoride reduces decay by making enamel more resistant. In contrast to very high prevalence of dental caries in this population, tooth brushing was commenced at very young age and nearly all children were using a tooth paste containing fluoride. High prevalence of dental caries in the presence of good oral hygiene practices, points towards wrong feeding practices as the cause. A study conducted in the same area revealed a high prevalence of wrong feeding practices, like overnight feeding beyond two years of age and adding sugar to formula milk
Pattern of dental decay described by this study is similar to findings of earlier studies
. Most commonly involved teeth were the maxillary incisors and these accounted for nearly half of the carious teeth. When children are fed at night, milk tends to pool between the upper lip and maxillary incisors. Carbohydrates in milk are fermented by bacteria leading to dental caries
. In contrast incisors of the lower jaw had a very low prevalence of caries, probably because tongue and lower lip cover them from pooled milk. In the lower jaw, molars in both quadrants had high prevalence of caries. In the upper jaw first molars had high prevalence of caries but second molars had relatively low prevalence, which may be due to late eruption. Canines were the least involved, probably because their shape providing some protection from caries.
The major limitation of this study was not using a dental mirror when examining teeth. Due to this only dentinal caries could be studied. The actual prevalence of dental caries will be higher than described by this study. The study setting was also not the ideal for this type of a study. Other limitation is, due to study population not representing the entire country finding of this study cannot be generalized as national figures.