Hepatitis B immunity in Indigenous children who received hepB vaccination in infancy

Oral Health Assessment

Children from Indigenous communities were among the first groups targeted to receive hepatitis B virus (HBV) vaccination in Australia because of a greater risk of infection from HBV.

This project, within the ABC study, will measure the current prevalence of HBV infection and long term (>10 years) persistence of HBV antibody in indigenous adolescents for the first time in Australia and the response to an HBV vaccine booster dose in children who have low immunity.

These long term follow up data on one of the first groups to be targeted by the National Immunisation Program are important as adolescence is a time of increased risk of hepatitis B transmission.

If clinically significant HBV infections are found to be rare and immunologic memory can be demonstrated in this cohort, this would provide good evidence to support the argument that booster doses are not required in the Australian context.

Internationally, this study will add to the limited information about anamnestic responses to hepatitis B vaccine in Indigenous adolescents initially vaccinated at birth.

There are two main things that are of interest to dentists in regards to oral health; dental decay and periodontal disease. Dental decay is also known as 'caries' and is caused when bacteria in your mouth combine with sugar from your diet and the acids produced by the bacteria slowly dissolve the enamel (outer surface) of the tooth. Under the enamel is another layer called 'dentine' and when decay reaches this level you might begin to feel some pain when eating hot or cold food. Sometimes when the decay gets too deep it infects the nerve or 'pulp' of the tooth; when this happens the tooth either needs to be extracted or to have a 'root canal filling'. The way dentists measure dental decay is by recording all the surfaces of the tooth (some teeth at the back have five surfaces). A tooth surface can be 'sound', 'decayed', 'missing due to decay' or 'filled due to decay'. Fluoride in toothpaste and drinking water help keep the enamel of the tooth hard; this is why it is important to brush your teeth and to drink fluoridated water.

Periodontal disease involves the gums around the tooth. It is also caused by bacteria in the mouth or in 'plaque'. The first stage of periodontal disease is called 'gingivitis' which is when the gums bleed a little bit when you eat an apple or brush your teeth. When gingivitis becomes more progressive, the bone underneath the gum that supports the tooth begins to dissolve, sometimes making teeth very loose. This is called periodontal disease. When dentists measure periodontal disease they take a small 'probe' and measure two sites in the gum around every tooth. The first measure is to see where the gum sits in relation to the top part of the tooth and the second measure is to see how much bone loss has resulted as a consequence of periodontal disease. Periodontal disease is associated with diabetes; if you have diabetes there is more likely to be loss of attachment of your periodontal tissues and if you have periodontal disease you may be at higher risk of becoming diabetic. The best way to prevent periodontal disease is to eat lots of healthy, fresh food and to brush you teeth twice a day so that bacteria does't build up around the gum-line.