Oral Health & Dental Caries

Most people have heard about caries, also known as tooth decay or dental cavity. Possibly, many have already experienced having it at least once in their lives. But what is it and what causes it? It goes beyond the simple cliché “don’t eat sweets or you will have dental caries”, and this is what we are going to talk about today. 

Dental plaque & Caries

Dental plaque, an “oral biofilm”, is an organised matrix of bacteria, found on the surfaces of our teeth and that cannot be removed by rinsing with water. The mechanical removal of plaque with a toothbrush and floss is shown to be the most effective way to remove plaque if performed correctly.  

The progression of Caries 

Tooth decay is caused by the presence of cariogenic bacteria within this plaque. These bacteria are called Streptococcus Mutans (S.mutans). The acid produced by these bacteria “attacks” the enamel (the outer layer of our teeth and the hardest tissue of our body) and ends up softening it. This results in loss of tooth structure, or, in other words, a cavity! 

The longer the cavity remains untreated, the deeper it becomes. The bacteria keep degrading beneath the enamel and into the second layer of our teeth (called dentin), which is naturally softer. If caries continues to progress, it can reach the pulp (centre of the tooth which contains the nerve, blood vessels and connective tissues). In this case, root canal treatment will have to be performed (i.e. the complete removal of the pulp).

The very early stage of caries may be reversible, depending on how much enamel is destroyed. If caries does spread, however, it is important to visit a dentist for restorative procedures, as soon as possible, that's one of the reasons that it is so important to visit your dentist for regular check-ups (every 6 months or according to your dentist's recommendation). At this appointment, the dentist will identify potential cavities in their early stages and treat them before it becomes irreversible.  

Childhood caries in Australia

According to the Australian Institute of Health and Welfare, “dental decay is relatively common among Australian children”. A study in 2016 showed that almost 1 in 4 (24%) children aged 6–14 had experienced caries in their permanent teeth. It also showed that more than 1 in 9 children (11%) still had decay that was untreated.  

It is really important that parents encourage and reward proper dental practices at home by the time the first tooth erupts. This includes brushing the infant's teeth (yes, even if there is only one!), and avoiding food and drink with added sugar 

How to prevent it?  

Prevention is key and it involves a number of actions: 

• Avoid sweet foods and sugary drinks (if you do have any, make sure you rinse with water and don’t leave it too long to brush your teeth);
• Brush your teeth twice a day for 2 minutes each time;
• Use a fluoride toothpaste (following the recommended amount) on a soft toothbrush (manual or electric); 
• Clean your tongue with a tongue scraper or toothbrush;
• Floss between your teeth at least once a day or use an inter-dental brush;
• Have regular dental check-ups every 6 months or according to your dentist. 

The importance of fluoride 

Fluoride is essential to combat tooth decay. This is how it works: fluoride gives our teeth better resistance against the cariogenic bacterial which causes tooth decay, through the inhibition of bacterial activity in dental plaque. It also reduces demineralisation of enamel by acids produced by these bacteria and may remineralise early enamel caries.  

However, it is important to be careful with the risk of fluorosis (overexposure to fluoride during the first six years of life, when the enamel of permanent teeth is formed).  

Australia’s fluoride guidelines recommend brushing teeth twice a day from 18 months and at least twice a day from the age of 6. On the toothbrush, it is recommended the use of a smear of low-fluoride toothpaste (about the size of a grain of rice) once the child is one-and-a-half. For children aged 3 to 6 years, use a pea-sized amount.  

It is important to remember that water fluoridation in Australia is an effective public health measure and helps to prevent tooth decay when associated with a healthy diet, good oral hygiene, appropriate use of fluoridated toothpaste, and regular dental check-ups. 

Should I use a mouthwash as well?

There are different types of mouthwashes aimed at specific results. The two main types are: cosmetic and therapeutic. 

Therapeutic mouthwashes are available both over the counter and bought on prescription, depending on the formulation. These help with specific oral conditions (your dentist must recommend this for you).  

Cosmetic mouthwashes address short term oral conditions, such as bad breath. Often these will have a fresh taste and smell, however, it is important to remember that: mouthwashes do NOT substitute the combined effects of “brushing and flossing” your teeth, especially the cosmetic ones.  

Children younger than the age of 6 should not use mouthwash unless recommended by a dentist. This is mainly because they may swallow large amounts of the liquid inadvertently. 

References 

1. Heng C, Tooth Decay Is the Most Prevalent Disease. Fed Pract. 2016 Oct; 33(10): 31–33. 
2. Boggess KA et al, Knowledge and beliefs regarding oral health among pregnant women. J Am Dent Assoc. 2011;142(11):1275–1282. 
3. Fontana M, 2018, National Institute of Dental and Craniofacial Research, <https://www.nidcr.nih.gov/health-info/tooth-decay/more-info/tooth-decay-process> 
4. Lei M, Caries remineralisation and arresting effect in children by professionally applied fluoride treatment – a systematic review. BMC Oral Health 16(1), 2016 
5. Health Direct, 2018, Health Direct, <https://www.healthdirect.gov.au/teeth-cleaning> 
6. Claydon NC, Current concepts in toothbrushing and interdental cleaning. Periodontol 2000 2008;48:10-22.  
7. Ha DH et al, Oral health of Australian children: the National Child Oral Health Study, Children’s oral health status in Australia, 2012–14. In: Do LG & Spencer AJ (eds). 2012–14. Adelaide: University of Adelaide Press. 
8. Australian Dental Association, <https://www.ada.org.au/Your-Dental-Health/Children-0-11/Fluoride> 
9. Kanduti D, FLUORIDE: A Review Of Use And Effects On Health. Mater Sociomed. 2016 Apr; 28(2): 133–137. 
10. Department of Scientific Information, ADA Science Institute, 2019, < https://www.ada.org/en/member-center/oral-health-topics/mouthrinse>