Why do we value White Teeth?

Human Beings since the times of ancient civilisations have always valued a nice set of pearly white teeth. In fact the Ancient Egyptians and Ancient Romans are recorded as having developed methods of tooth whitening (methods that we definitely no longer recommend today!). The Arabs of 7th century AD were also known to value oral hygiene and white teeth and used to use bristles of olive tree branches – known as the miswak – to maintain their oral health.

Rather instinctively, we associate a nice set of white teeth with the following:-

Youth
Beauty
Intelligence
Friendliness
Confidence
High Self-Esteem

In a world where initial impressions matter, it is little wonder then why we put such importance on having a nice white smile!

Understanding Tooth Structure

Maintaining a nice healthy white tooth colour can only be done so by understanding the structure of natural teeth themselves.

The visible portion of teeth above the gums comprise of 3 important layers: the enamel, dentine (or dentin for our North American visitors), and the pulp chamber which contains the teeths’ nerves and blood supply.

Above: Cross-sectional diagram of a typical tooth showing the enamel, dentine and pulp layers

Our enamel is the outermost layer of our teeth and it is in fact the hardest substance right throughout the human body. Although enamel is typically translucent – meaning that light passes through it in normal circumstances - its thickness and condition is important for determining our tooth colour (or shade). We will discuss more about enamel health in future sections.

It is however the next layer – the dentine – which is the primary determinant of our tooth shade. In some instances the health of the pulp is also an important determinant, but again this will be left for a future blog post.

Why do teeth discolour?

So you’ve just had your teeth whitened at your dentist. The question that always gets asked is: how do I maintain this beautiful new smile for as long as possible?

The key is to understand why teeth discolour in the first place. There are two broad types of discolouration:

1. Extrinsic staining - this is the build up of stains on the outer surface of the tooth over time. Staining may or may not be accompanied by calculus or tartar. In general, these stains appear due to the presence of dark pigments in foods and drinks. A basic rule to keep in mind is that if any food looks like it may stain, it will stain. Tea and coffee are known to be especially guilty in this regard.

2. Intrinsic discolouration - this is when the colour of the tooth changes internally. Many of the same pigments that can cause extrinsic staining can also cause intrinsic discolouration over time due to the presence of pores on the outer surface of the enamel. When these staining pigments pass through the enamel, they lodge in the second layer – the dentine. When these pigments build up in the dentine over time, this is what gives teeth a yellowish or brownish hue.

Did you know: Professional teeth whitening should be done ideally not long after having a routine scale and cleaning in which the extrinsic stains are first removed. Once these are cleaned, teeth whitening agents can penetrate the enamel and whiten teeth by breaking up the pigments that have lodged within the dentine.

Tip #1: Get the basics right about brushing and flossing

The rules of life are as follows: no progress can be made without hard work, no dreams realised without taking action, and no white smiles can be maintained without toothbrushing!

Implementing a routine habit of brushing at least twice a day is a fundamental requirement for maintaining white teeth. Brushing three times per day is of course even better, but more than that can definitely start to be considered as overkill. What is just as important, is the way we brush our teeth. Did you know that there are at least 9 (yes, nine!) recognised techniques for toothbrushing? There is no need to detail them all here but some basic principles need to be followed:

Brush all surfaces of all teeth – a toothbrush of ideal size and shape is required in order for this to be done effectively
Avoid horizontal scrubbing motions, as this is responsible for causing both toothbrush abrasion (the thinning out of enamel) and gum recession over time. Unlike scrubbing your bathroom floor, more force is not better when it comes to brushing our teeth!
Brush for at least 2 minutes – we need a minimum of 2 minutes exposure of teeth to fluoride toothpaste in order for our enamel to remineralise sufficiently
Do not brush for too long for the same reasons outlined in point number 2 above
Electric toothbrushes remove plaque more efficiently than traditional manual toothbrushes but both are acceptable

The next important habit is flossing, or interproximal cleaning. Did you know that the areas between our teeth can account for nearly 40 per cent of our tooth surface area? This is why cleaning between teeth – in areas where a toothbrush cannot reach – is crucial. Together with toothbrushing, our goal is to minimise the amount of bacterial build up – or plaque – on and between our teeth over time. It is plaque which can not only cause staining and discolouration but act as reservoirs for bacteria which themselves discolour and stain teeth – known as chromagenic bacteria.

Tip #2: Use the right tools

As we indicated above, the most effective way we can maintain good hygiene and a nice white smile is with effective toothbrushing and flossing. To do this, we need to be using the right tools.

When it comes to your toothbrush – whether manual or electric – a brush of ideal shape and size is required to access all surfaces. People with very difficult or tight access towards the back of the mouth would benefit by using a toothbrush with a smaller head. Similarly, patients with orthodontic braces may benefit by using toothbrushes specifically made to get around these appliances into tight spots. Make sure to use a soft bristled toothbrush. Medium and hard toothbrushes can wear enamel over time. Ignore the temptation to brush with excessive force regardless.

When it comes to cleaning between our teeth, traditional string floss, flossettes, interproximal brushes, as well as electric air and water flossers are all effective in this regard. The best method varies for each and every one of us. Ask your dentist what the best methods may be for you on your next check-up...

Tip #3: And on that note, never miss your routine check-ups and cleans!

Depending on your specific needs, you should be seeing a dentist every 3-6 months. Your dentist will usually make a recommendation based on your treatment history, condition of your teeth and gums, and overall oral hygiene. Furthermore, stains and calculus tend to build up in a non-linear manner. This means that with time they build up on teeth in a manner that is accelerating. Not only are stains and calculus responsible for ruining the healthy white luster of teeth but they are also the guilty party behind gingivitis (or inflamed gums), bad breath, loss of taste, and shortened kissing time. Only kidding – it’s rare that the sense of taste is lost completely 😉

Excessive stains and calculus – if left uncleaned – can also negatively impact on the integrity of tooth enamel. When the enamel surface is roughened over time, they attract even more stains, which only compounds the issue even further. If maintaining a white smile is your priority then your dentist may also recommend one of many touch-up treatments.

Tip #4: Rinse and rinse well

As promised, we’ve included a specific tip for the tea and coffee drinkers especially (and any other dark staining fluids)! Staining and discolouration typically arises when pigments from such foods and drinks are allowed to settle on the tooth surface and go undisturbed for hours. By undisturbed, we mean to say that there is nothing to dislodge them from the tooth surface particularly if some stains are already present or if the integrity of the enamel is compromised and the surface is no longer smooth. Further compounding this issue is the fact that such drinks are typically acidic in nature. This means that the acid acts to dislodge minerals from the enamel surface which makes them more prone to picking up staining. This is even worse when sugar is present!

Rinsing with a flouride mouthrinse immediately after drinking tea or coffee is an effective way to ensure the following:

Stains do not have enough time to settle on teeth
Fluoride ions help to remineralise the surface enamel layer and render it smooth once again

If no fluoride mouthwash is present, then at least rinsing with water is recommended.

What if we just brush our teeth straight away instead?

Toothbrushing immediately after food or drink consumption is not recommended. This is because the environment in our mouths is acidic and the surface enamel has been weakened, meaning that the physical abrasion of toothbrushing can actually thin out our enamel over time. Unfortunately once lost, enamel cannot be regenerated. Instead, wait at least 30 minutes after eating or drinking before brushing your teeth!

Did you know: teas and coffees that have been diluted with milk tend to stain less than darker equivalents. This is because milk and their alternatives neutralise the acidity of tea and coffee slightly (not completely!) and their inclusion means that less staining compounds are present overall.

That brings us to an end to Part 1 of our 4 part series on maintaining a whitened smile. In Part 2, we will discuss the following and their effects on tooth colour:

Liver and blood cell health
Acid erosion and sensitive teeth
Amalgam fillings and the adjacent natural tooth
Gum disease and recession
Teeth grinding and cervical abfraction

#keepsmiling #loveyoursmile #smilewithconfidence

Maintaining a White Smile - Part 1