Preventative Dentistry

Essentially preventive dentistry is aimed at retaining healthy teeth and gums throughout life. Young people tend to lose teeth through tooth decay and adults lose teeth through periodontal (gum) disease. But this doesn’t have to be the case.

A dental examination

A routine dental examination is part of preventive dentistry. You will be asked to fill in a new medical history form on an annual basis. This will allow us to assess any possible interaction with any medication you are taking if any, and your dental treatment and your dental status. Some medications can cause an abnormal growth of the gum tissue, while others can cause a dry mouth.

The mouth is part of the body and often reflects the first signs and symptoms of many systemic diseases, for example, vitamin B deficiency.

The examination starts on the outside of your head, noting symmetry, jaw opening and lateral movements and checking the lymph glands under the jaw. Next, all the soft tissues inside the mouth are inspected as far back as the tonsillar area. Then the teeth are examined in detail, looking for discolouration, cracks, stain, wear facets, toothbrush abrasion, abnormal tooth movement and of course decay. Also noted is the amount of plaque and calculus present as well as toothbrush abrasion and gingival recession. The gingivae are also checked for inflammation.

Periodontal disease

Periodontal disease is caused by the formation of calculus (tartar) around the necks of the teeth. This build-up of calculus is full of bacteria that excrete toxins that directly cause bone loss leading to loss of tooth support. Calculus is rough and ulcerates the gingivae causing gums to bleed particularly when brushing. This is the first sign of periodontal disease. Periodontal disease is painless in its early stages and often the first thing the patient knows is that the teeth are becoming loose. At this point, it is often too late as we cannot grow new bone to support the teeth. Calculus is formed from plaque that builds up on the teeth, and starts as a mixture of saliva, mucins, bacteria and food debris.

Depending on the pH of the plaque and the type of bacteria in the plaque, determines whether it will lead to tooth decay or periodontal disease. If the plaque hardens becoming calculus, it continues to build up creeping down the tooth root, destroying the periodontal ligament and bone as it goes. Generally, it is a slow disease that takes many years to get to an advanced stage. Again the best defence is thorough brushing and flossing twice a day.

It can be seen that the mainstay of preventive dentistry at home is using a good fluoride toothpaste with a small soft toothbrush together with a meticulous brushing technique as well as thorough flossing to ensure a healthy dentition for life. But as previously stated, we cannot be 100% efficient in our cleaning efforts, and once the plaque hardens to form calculus, we need professional help.

The reason we ask patients to have six-monthly check-ups is to monitor their efforts at home, advise new techniques as indicated and remove calculus if need be. Once plaque becomes calculus, only a dentist or hygienist can remove it. There are many other services a dentist can offer that fall into the category of preventive dentistry. I will deal with topics individually below.


Simply put, there is a triangle of decay. The three sides of the triangle are teeth, bacteria, and sugar (simple carbohydrate). Remove any one of these and you will have no decay. Obviously, if you have no teeth you have no decay, but that defeats the purpose. If we remove the bacteria by brushing and flossing thoroughly we will stop decay.

If we remove all sugar and simple carbohydrates from the diet we will have no decay. Clearly, it is impossible to clean out teeth 100% efficiently, and we do need some carbohydrate as part of the normal balanced diet. It is however easily achievable by cleaning and flossing thoroughly twice a day and reducing the number of simple carbohydrates we eat, that is simple sugars that are fermented by the bacteria in our mouth to form acid. I will deal with sugars in depth later.


Bite-wing x-rays are generally taken every two years and allow us to check the level of the bone that supports the teeth, to find decay between teeth and check the margins of existing restorations as well as monitor early decay. Over time in history is built up that can be sequentially reviewed. For example and early decay can be re-mineralised avoiding the need for a filling and this can be monitored over time. OPG x-rays are generally taken every five years and give us a good overview from the floor of the nose to below the chin and often including the temporomandibular joints. These x-rays are particularly useful for assessing wisdom teeth, periapical tissues and bone lesions. Again successive x-rays can be compared over time. Occasionally people worry about the amount of radiation in taking x-rays.

Many people are unaware that we are constantly subjected to many types of radiation from the sun, ultraviolet being the one everyone is aware of, but also we are constantly being bombarded with cosmic, gamma and x-radiation. The atmosphere of our planet reduces the impact this radiation has on us. Whenever we fly we are exposed to more radiation than we are on the ground, and to put it in perspective the radiation from two bite-wing x-rays is about the same as the extra radiation taking a flight from Melbourne to Sydney.

At Dentist On Collins, we have modern x-ray machines and continue to use a lead apron to protect your body, particularly the thyroid and in the case of young children the thymus gland as well.

Periodontal Charting

In recent years we have introduced periodontal charting for all patients over 30 years of age, and younger if indicated. Periodontal charting is where we measure the crevice depths around each tooth at six defined points. It is the only quantitative gauge we have to indicate periodontal health. Healthy crevicular depths range from 1 to 3 mm. Any more than this indicates the possible presence of periodontal disease.

Periodontal charting is done every two years and builds up a history over time that monitors periodontal health, so we can see if our efforts and our patient’s efforts at home are maintaining, improving periodontal health, or the situation is deteriorating.

Fissure sealing

When the back teeth develop, they have particular shapes according to which tooth they are. When the patient looks at their teeth in a mirror, they see hills and valleys. We call them cusps and fissures. The fissures can be particularly deep and in some cases be an actual defect in the tooth. Fissures are very hard to clean, but an ideal place for bacteria and food to remain. This is the number one area for tooth decay. These fissures can be sealed with a resin that locks into the enamel, making it easier to clean the teeth and eliminating the potential for decay.


The benefit of fluoride has long been known, but only recently understood. When the teeth first erupted into the mouth, the enamel is immature, and through repeated dissolving and re-mineralisation, becomes mature enamel. Acidic foods dissolve the calcium out of the surface layer of teeth, and when the pH returns to normal about half an hour to an hour later the surface of the tooth can re-mineralised under favourable conditions. In the 1950s it was noted that two similar towns in New Zealand, namely Napier and Hastings, the children had different rates of dental decay. It was discovered that naturally occurring fluoride reduced the amount of decay in children living in one of the towns. This has led to the fluoridation of water supplies around the world.

There has been much controversy surrounding fluoridation, but like many elements, it is essential for good health. It is amazing that there is no controversy about the addition of iodine to salt to prevent thyroid problems, which was endemic in Australia and New Zealand due to the lack of iodine occurring naturally in the diet. The main proprietary brands of toothpaste contain fluoride, as it continues to have a beneficial effect on the surface of mature adult teeth.

Colgate has recently included Arginine in their toothpaste to reduce decay by neutralising sugar acids. Read more:


Sugar has been legally been defined as sucrose. It is however only one of many sugars that are more properly regarded as a fermentable carbohydrate, the simplest of which is glucose. Two glucose molecules form sucrose and so the sugars build in complexity to include fructose, lactose and others. In simplified terms, these fermentable carbohydrates are metabolised by bacteria into acid which is leads to tooth decay.

Today many foods are highly refined and contain high amounts of hidden sugar. The effect is that these foods tend to clag on our teeth to the bug’s delight. Highly refined and high sugar foods and drinks are causing obesity and tooth decay in developed nations. During the two world wars, sugar was severely rationed and tooth decay dropped dramatically. Once rationing ceased, decay rates returned to pre-war levels. There is a direct link between sugar consumption and tooth decay not to mention obesity and diabetes, both of which are increasing at an alarming rate.

Being aware of the sugar content of foods and limiting the total amount of sugar that you eat, will have beneficial effects for your teeth and your health generally. Obviously brushing and flossing away the food debris is important too.


So your best preventive approach is to avoid excessive sugar consumption, clean your teeth thoroughly twice a day by brushing and flossing and have a professional dental check-up twice a year, or as recommended by your dentist.

Copyright Dr Richard Skinner 2020

error: Content is protected !!