Welcome back to part 2. If you haven’t read part 1 then
first of all, shame on you. Secondly, this post should still make sense if you
haven’t read the prequel however there are some terms that I use that are what
boffins call “ technical jargon” so if one of those comes up just refer back to
the previous post where I will have explained myself. These posts are long
enough without me defining things twice!
The first thing we have to address in terms of things
that cause discolouration is dental disease and thus the first things to
discuss will be……..
1) options of treatment to address disease:
a. This
includes a number of different things depending on the disease process.
i. Removing
and filling cavities due to decay
ii. Performing
root canal treatment on teeth where the nerve has died. This alone can improve
the appearance of the tooth however sometimes the discolouration (usually a
greyish colour) can remain or a slightly different tone of staining can occur
due to whatever materials we use to fill the root canal system. The rubberised
material we put in the cavity where the nerve sits (the root canal) (p.s. I
have done a whole blog post on root canal treatment so if you want any
clarification about this please refer to that) is a slightly pinkish/peach – a
salmon colour if you will. This can cause discolouration by itself as the tooth
is slightly translucent and this peach colour will show through. Other
materials used in complicated cases of root treatment, usually in children or
where perforations/punctures have occurred during root treatment on adult
teeth, can cause dark discolouration due a reaction between the chemicals in
the material and the tooth.
iii. Placing
tooth coloured material over teeth with reduced enamel. As I mentioned earlier
teeth with reduced or poor quality enamel can be due to things you are born
with, such as amelogenesis imperfecta as shown above, or things that have
happened as you have been living for example eating too much acid, or suffering
from things such as gastric reflux. I will go more into the types of ways we
can restore/fill/reshape in my blog post about tooth wear but I just wanted to
mention it because certain things cannot be improved superficially by a
chemical agent and need masking.
2) Correction
of discolouration from previous dental treatment. This includes:
a. Replacing
metal fillings with white ones. As a word of warning with this, the chemicals
in metal fillings leach out over time as corrosion products form– a bit like
leaving something metal on a wet surface, you will find that the rust will
discolour whatever surface you have left the wet metal object on. The same
occurs with these corrosion products so even though we remove the metal
(amalgam) fillings and replace it, the tooth may appear grey. Similarly, you
must bear in mind that every time you remove and old filling to replace it,
tiny fragments of tooth are also removed/we remove tooth which is not decayed
but is stained and therefore reduce the total amount of remaining tooth. Over
time this will of course lead to less and less tooth tissue so it is not a step
to be taken willy nilly (thrilled that I managed to get that phrase in).
b. Modification
of existing root canal treatment. If you have a discoloured tooth that is root
treated (to a good quality I might add) then we can make certain changes to it
to help improve the appearance. The most simple is to replace the filling in
the tooth as sometimes root filled teeth are restored with metal fillings and
so replacing with a white one can improve the appearance (but do bear in mind
what I just said in point a). The second thing that can be done is to cut down
the existing root canal filling. As I mentioned before, the pink/peach colour
of the root filling can give the tooth a coloured tinge. Therefore, if you cut
this down below the gum level then this eliminates this possible cause of
discolouration. Again, word of warning, this needs to be done under rubber dam
(again refer to my root canal treatment post for pictures of this) because if
the tooth gets re infected by bacteria in the saliva then no amount of
whitening will help you.
Once the disease has been dealt with then we can consider
other options. For this I shall create a clever analogy. Or at least it seems
clever while I sit here surrounded by the scent of Olbas Oil and sipping Lemsip
(other brands are available).
Think of teeth like nails, or like a table surface
(trying to cater to a wider audience here – bear with me).The different methods
are basically akin to improving the nail/table appearance or removing stain
using:
·
Nail varnish remover/surface cleaner like Mr
Muscle
·
Using a harsher chemical which will strip
some of the colour out of the nail (like a nail brightening treatment) or
lighten the colour of the wood table.
·
Buffing over the surface of the nail/table
with a sandpaper type substance to smooth out ridges and bumps and get rid of
any tougher stains
·
Re-covering the surface of the nail/table
with varnish or a laminated layer.
So using my wondrous above analogy (which probably will
seem ludicrous when I read it back and I’m not ill but let’s go with it)
1) Cleaning
the surface can include a number of means.
a. Certain toothpastes can improve the appearance
of teeth. Please avoid using abrasive toothpastes – the infamous smokers’
toothpaste or those with bicarb in. The reason for this is that yes, it will
remove the stain but in the same way as sandpaper will do. The stain vanishes
because the enamel vanishes. As I mentioned above, reduced quantity of enamel
will automatically lead to the teeth looking more yellow because of the
underlying dentine. Therefore you are actually doing more harm than good by
using these.
There is very little reliable research about “whitening” toothpastes
because usually the studies are carried out by the big toothpaste companies
themselves and so the results will be a little “biased”.
A study by Moran testing regular toothpaste against a
whitening one showed that “the test product [the whitening toothpaste] may have
some advantage over the conventional paste at removing stain but the magnitude
of difference would appear to be small and of little clinical relevance”.
Sharif’s study published in the BDJ concluded from
their study that “only a small number
of the whitening toothpaste products have good chemical stain removal
potential; the majority are unlikely to achieve their claimed benefits through
chemical stain removal”
Çakmakçıoğlu (wouldn’t like to try pronouncing that)
however found that the whitening toothpastes they testing in their study over a
4 week period were in fact effective at having a whitening effect on teeth. But
slightly obviously but worth pointing out – greater effects were seen with
greater staining as it was an improvement in colour that was measured. So going
from mud brown to beige would demonstrate a greater improvement than going from
cream to off white and so it depends what it is that you are hoping to achieve from
the toothpaste.
b. The
next option is dental cleaning – your scale and polish type option. This is one
of the most effective ways to remove stain. It will not improve internal
staining of the teeth which occurred when growing up/developing, nor will it lighten
the base colour of the tooth which darkens with age, but it will significantly
improve any staining of the teeth caused by food, drink or chlorhexidine
mouthwash. It is the option that I turn to most regularly because I know the
base colour of my teeth is fairly light but I pick up stain from things I eat
and drink/when I’m hit by a bout of pericoronitis (again, if you don’t know
what this is then shame on you, refer back to my blog post on wisdom teeth to
be enlightened). This has to be done by a professional and it is always worth
trying this first as whether you pay NHS costs of privately, a scale and polish
will be significantly cheaper than paying for other whitening treatment and so
even if it does not provide the desired effect, you have tired it and not lost
anything as if nothing else the scale will improve the gum health and similarly
if you decide to progress to other whitening treatments then you will still
want the surface stain removed otherwise things like whitening gel will just be
bleaching the stain rather than the tooth itself.
2) Onto
the harsher chemical analogy. This is the better documented whitening treatment
using a whitening gel/bleach. This is split into the conventional type of tooth
whitening and something called “internal bleaching” or “non-vital bleaching”. I
will start with the latter because it is shorter and easier to explain and then
I can be free to waffle on about conventional/external tooth whitening
a. Internal
bleaching is “indicated for non-vital, endodontically treated teeth which have
become discoloured due to the deposition of blood degradation products in the
dentinal tubules”. Thanks Royal College of Surgeons. I shall now translate.
Firstly, the non-vital endodontically treated bit basically means dead and root
treated teeth. It is important that this root treatment is of good quality (you
can refer to my root canal post for what this means) otherwise you are just
approving the appearance of a tooth which will end up in the clinical waste in
a few years. When a tooth dies, the blood supply also dies off and any
remaining blood in the tooth starts to break down like when you cut yourself, a
scab forms and eventually this scab breaks into pieces and falls off, except in
the tooth it is trapped and has nowhere to go so simply leaches out into the
surrounding area. This leads to the dark colouring of dead teeth.
b. Below
is a somewhat helpful picture to try and explain this. It helps if it makes a
bit of sense but if it all goes over your head don’t worry, it’s unlikely that
you will ever be confronted with a pub quiz question on this topic.
c. Translation
done, now what can we do to improve this? Because the discolouration is inside
the tooth applying bleach to the outside will have little effect because it cannot
soak through the protective enamel layer to get to the dentine where the blood
products are causing the staining. Therefore we have to find a way to get
inside the tooth. Luckily enough, in root canal treated teeth an opening has
already handily been made. Therefore the process goes as follows:
i. Check
that the root filling is good quality
ii. PUT
ON RUBBER DAM. Sometimes, and I mean sometimes, you can get away without using
rubber dam. For example if it is a front tooth and the person you are working
on is guaranteed not to stick their tongue in the tooth before you’re finished.
You would assume most people have control of their own body parts but sadly
tongues seem to be excluded from this and it tends to wander to the exact place
you don’t want it to be.
iii. Remove
the filling in the back of the tooth. It is worth noting that although I said
earlier about not being able to improve the colour of a veneer or crown, if the
tooth underneath the veneer/crown is discoloured due to the above process this
can affect the shade of the restoration simply because it shines through. Like
putting a layer of white of paint on a black wall, it will always appear a bit
grey. Therefore, although ideally the internal bleaching should be done prior
to any veneer/crown placement, it can have some effect when done after if the
restoration looks a bit grey and it can’t be explained by the fact that the
crown has a layer of metal in it etc.
iv. Trim
the rubberised root filling down to below the gum line so that this is not
having an effect on the colour.
v. SEAL
THE ROOT FILLING.
vi. Place
a small amount of the chosen bleaching agent – this is usually some derivative
of hydrogen peroxide like carbamide peroxide but it is very much personal
choice as to what type and what concentration is used – into the space in the
back of the tooth.
vii. Place
a temporary filling over the top
viii. After
3-5 days this temporary filling and bleaching agent should be removed and
replaced with new ones. We recommend doing this several times until the colour
is one that you are happy with/the tooth will not go any lighter.
3) Conventional/external
bleaching. This is the one you will be most aware of. There are, of course, a
number of different ways of doing this. There are some ways which are better
than others and some ways which are frankly, a load of marketing rubbish and are
as effective at whitening your teeth as waving a magic wand over them and
chanting something, and if this works for you then you have harnessed a method
much more powerful than any whitening gel the dental industry can provide you
with.
a. The
first important thing to bear in mind that you should only be undergoing any
form of tooth whitening with a dentist (or at least a dental practice). If you
are the sort of person that would be prepared to have plastic surgery done in
the back room of a dingy sunbed shop then go ahead and do the same with your
teeth but please know that it is actually illegal for anyone other than dental
professionals to purchase the “bleach” used for tooth whitening. Therefore
anyone other than a dentist using “bleaching products containing more than 0.1%
and up to 6% hydrogen peroxide present or released
from other compounds or mixtures in these products” is breaking the rules set
in place by the EU and therefore if any problems occur you have very little
legal defense because no one other than dental professionals should be in
possession of these products.
b. I say dental professionals as apparently the GDC
had a meeting in June 2008 where they decided that “in addition to dentists being
able to carry out tooth whitening, dental hygienists and dental therapists, on
the prescription of a dentist, can carry out tooth whitening as an additional
skill”.
c. Therefore, as long as you have an initial
examination by a dentist who deems it is in your best interest/it is
appropriate for your teeth to undergo tooth whitening, then the actual process
can be completed by a dentist or dental care professional.
d. Now for the nitty gritty as they say. There are
a couple of different recognized techniques for tooth whitening and there are a
couple of added things that the dental companies with money to spare have
created which are utter crap. The 2 methods are either in surgery bleaching, or
at home bleaching
Home tooth whitening process
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In surgery tooth whitening
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The first step of this generally involves a scale and polish, or at
least it should in order to remove any stain from the teeth as I mentioned
earlier so that the whitening gel is whitening the tooth not the stain/gunk
on the surface.
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Ditto as for home whitening for
the same reasons
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It is worth noting that one of the many many reasons it is so
important that a dentist plans your whitening treatment because types of
fillings you have can have an impact on treatment. In some cases, poor
quality/leaking metal (amalgam) fillings react very badly with the whitening
gel. This leads to corrosion products from the metal filling leaking out into
the surrounding tooth and making it go, well, green. Which I’m pretty sure is
not what you’re aiming for.
SO if you have metal fillings that have been placed fairly recently
i.e. within a couple of years, have been sealed well and have no leaking
around them (your dentist will be able to see this) then you will absolutely
fine however there is still the dilemma that you will have nice white teeth
with whopping great silver/black blobs in them. If your metal fillings have
been there a long time, or have leaking around them then they either need
replacing with another metal filling (which can be done on the NHS) or a white
filling (which will most likely be a private only option).
It is worth therefore bearing this in mind and factoring this into
your time scale, as replacement of fillings can take several sessions
depending on where they are in the mouth
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The in surgery version involves
a one time application of tooth whitening bleach by your dentist. This is
where the marketing BS takes over. You can get various “special lights” that
are then held over the bleach on the teeth. This light does precisely
nothing. The companies themselves will in fact agree with this. It just means
they can charge more for provision of said light. Anyway, this method leads
to a certain amount of lightening of tooth colour and no further improvement will occur unless
you have it done again. In these cases because it is a one-time application
the strength of whitening gel will be higher than what we give for home use.
The problem with this is that it gives limited results. What your teeth look
like when you leave the surgery is what they will look like and will only get
darker as you eat and drink and stain them up again.
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Next we take impressions of your upper and lower teeth in order to
make whitening trays. These basically look like clear gum shields.
Yes we know you hate impressions. Tough.
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For this reason I generally
recommend at home whitening because you can continue to whiten the teeth
until you reach the desired shade. You can then continue about your daily
life, allow the teeth to become stained, then re whiten them again for
whatever event you have coming up.
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The lab then turn the impressions we take into stone models of your
teeth and construct the whitening trays. They are basically clear plastic gum shields which
fit over the teeth and allow for a small amount of bleach to be held over the
teeth for an extended period of time so it can have time to get working.
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The dentist/hygienist should then try in the trays and check you can
take them in and out, otherwise we risk you being having to go to work with 2
plastic trays stuck in your mouth because you have no idea how to get them
out. Not that it’s difficult, it just gets held in by suction but there is a
certain trick to flicking them out.
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Then you should be given some of the whitening gel which could be any
variety of hydrogen peroxide or hydrogen peroxide under the guise of
something like carbamide peroxide. It’s all much of a muchness.
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Now the important thing is how much gel to use. There is a miniscule
amount of space between the plastic tray and the teeth. For this reason a
very small amount of gel will spread its way around the tray. If you put too
much in it will simply squeeze over the top and go all over your gums or get
swallowed. This is a very expensive snack considering that most dentists
charge upwards of £200 for their whitening “service”.
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The evidence shows that the gel becomes inactive i.e. will no longer
have the capacity to whiten teeth after about 2 hours. Usually dentists say
to sleep in the bleaching trays. This is ok short term but wearing trays
overnight on a regular basis for an extended period can lead the teeth to
shift around slightly so is not recommended. If you are able to sleep in the
trays then go for it, if not, a good time is after food. So…
1)
Eat your breakfast/lunch/dinner/tea
(catering for all dialects there)
2)
Brush your teeth – properly
3)
Apply a small amount of gel into the
whitening trays
4)
Put the trays in, if any gel seeps over the
top of the trays onto the gums use a tissue or cotton bud to wipe it off.
Usually the bleach isn’t strong enough to cause any significant damage but it
can make your gums sore so best to remove it if possible
5)
Leave the trays in for at least 2 hours.
You will get some results if you leave them in for less e.g. an hour but you
will end up having to repeat the process more times to get to the desired end
point and so will get through the very small tubes of whitening gel very
quickly so it’s more a cost issue than an effectiveness issue.
6)
Take out the trays, rinse them well, spit
out any gel from around the teeth.
7)
What you do next depends on how your teeth
react. I know mine get really sensitive after bleaching so brushing for me is
a no no, however I know other people that brush straight away. Either way you
need to get rid of the gel sitting on your teeth so either wipe it off well
with a tissue/rinse your mouth/brush
8)
Along the lines of the sensitivity issue, a
good idea is to put some toothpaste into the trays and put them back in for
about 10 minutes. The fluoride and other de sensitising chemicals in
toothpaste will help to make the teeth slightly less porous and aid in
reducing sensitivity.
9)
If you are getting significant sensitivity
then you may need to drop the percentage strength bleach used or just accept
that whitening is not a feasible option for you. This happens very rarely –
in a recent study by Donly they found that out of 60 people in a whitening
trial, only one had to stop using their method of whitening due to
sensitivity. Similarly the ADA Statement on the Safety and Effectiveness of
Tooth Whitening Products reported that “tooth sensitivity and soft tissue
irritation are usually temporary and stop after treatment” but still recommend that “patients receive
a thorough oral examination, performed by a licensed dentist, to determine
the most appropriate whitening treatment. This allows the dentist to
determine if the patient has any contraindications to the procedure and to supervise
the use of bleaching agents within the context of a comprehensive,
appropriately sequenced treatment plan”. Very well said.
10) You
then repeat this process until your teeth reach an acceptable shade. This
could take days, weeks or months. Remember your teeth will be more liable to
staining after using bleach as it makes the tooth substance more porous so
beware what you eat and drink when you are bleaching. However if they do re
stain then you will have the whitening trays and can just continue to “top
up” the level of whiteness throughout the years.
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So, is putting bleach in your mouth safe, you might ask.
There is actually very little good quality evidence out there because it’s such
a cosmetic procedure and thus is not deemed as being very high brow or academic
thus there are few studies conducted by “true scientists”. Most of the data
therefore comes from the companies who make said whitening products which as
you can imagine leads to all sorts of bias – as nicely said by the authors of a
Cochrane review on the topic “all of the trials [included in the review of
evidence] were either sponsored or carried out by the manufacturers of the
products”
Dr Hasson the lead author of a review into the quality of
studies on whitening summaries this nicely: “People should be aware that there
is no available long term data on the effect or safety of these products.” The
review however did find that that generally after 2 weeks of use,
“tooth-whitening products worked better than no whitening treatment, and that
differences in product efficacy were mainly due to the levels of active
ingredients”. I.e. the concentration of either carbamide/hydrogen peroxide in
the whitening gels made a difference to the level of results people
experienced.
4) Microabrasion
“Microabrasion involves the removal of a
small amount of surface enamel and classically incorporates both ‘abrasion’
with dental instruments and ‘erosion’ with an acid mixture. The term abrosion
has been used by some authors”. Thanks Royal College of Surgeons. Time for
translation. This is basically controlled erosion of the very top layers of the
tooth substance with acid and then polishing away of this layer. A bit like using
a face scrub to remove the top layer of skin to reveal a nice fresh layer
underneath. I will explain it step by step but first of all, what is it good
for?
This works really well for tooth staining. By
this I mean staining of the tooth tissue itself rather than staining on top of
it caused by tea and coffee etc. Because only a very minimal amount of tooth
substance is removed this tooth staining can only be minimal. If the stain or
discolouration runs through the whole thickness of the enamel or into the
dentine then removing the top layer is not really going to make any difference.
Imagine trying to use a face scrub on a dark mole, you could remove the top
layer but underneath will still be dark. It is the same concept with teeth.
Whereas if the discolouration is fairly superficial – like a mark left from a
spot on this skin etc - then taking off
the top layer can make a significant difference.
For this reason it is good for things like
fluorosis.
The above pictures show examples of the sorts
of discolouration that can be really improved with micoabrasion. However it is
difficult to tell just by looking at teeth how far the discolouration extends
into the tooth. Often the lighter/whiter discolourations are fairly shallow and
only affect the top layers of the tooth, whereas the more yellow or brown
stains extend deeper into the tooth. However this is not to say that the
reverse situation is possible. Similarly, whilst the yellow/brown staining may
go deeper into the tooth, frequently it gets lighter as it gets further into
the enamel and so microabrasion can improve its appearance even if it does not
completely rid the tooth of the discolouration.
So that was your whistle stop tour of how to
lighten the colour of your teeth. I have managed to drag this out for 11 A4
pages so I think it might be time for me to stop and think about something
other than teeth for a short period. Hope this was helpful. Feel free to share,
comment or ask questions as you wish!
Reading and that
Donly KJ, Segura A, Henson
T, Barker
ML, Gerlach RW. Randomized controlled trial of professional
at-home tooth whitening in teenagers. Gen
Dent. 2007 Nov;55(7):669-74.
Hasson H, Ismail AI, Neiva G Home-based chemically-induced whitening of teeth in adults. Cochrane Database Syst Rev. 2006 Oct 18;(4):
Moran J, Claydon NC, Addy M, Newcombe R.Clinical
studies to determine the effectiveness of a whitening toothpaste at reducing
stain (using a forced stain model). Int J Dent Hyg. 2005 Feb;3(1):25-30.
Özcan Çakmakçıoğlu, Pınar
Yılmaz, Faik Bülent Topbaşı
Clinical evaluation of whitening effect of whitening toothpastes: A pilot study OHDMBSC 12/2009; 3(4):6-1
N Sharif1, E
MacDonald2, J
Hughes3, R G
Newcombe4 &
M Addy5 The chemical stain
removal properties of 'whitening' toothpaste products: studies in vitro bleaching
British Dental Journal 188, 620 - 624 (2000)
Alyson Wray and Richard Welbury Royal College of Surgeons Edinburgh Clinical Guidelines TREATMENT OF INTRINSIC DISCOLORATION IN PERMANENT ANTERIOR TEETH IN CHILDREN AND ADOLESCENTS
http://www.klockodentistry.com/MicroAbeforeKH_copy.jpg
http://www.ojrd.com/content/2/1/17/figure/F1?highres=y
http://www.dentist-charlotte-north-carolina-nc.com/images/root-canal-dentinal-tubules-3-anatomy.jpg
