Transcript Dental Erosion and Acid

ACID ATTACK
The effects of soft drinks on teeth
What we will learn today:
By the end of the lesson we will:
• Be able to describe tooth decay or erosion.
• Be able to explain the causes of tooth decay.
• Be able to suggest how tooth decay & erosion
can be prevented.
Useful words:
• Acid – a chemical with a bitter, sour taste that
can dissolve some materials.
• Enamel – the hard outer covering of the teeth.
• Erosion – the process of a material being worn
away.
• Neutralize – to stop something having an effect.
• PH Scale – a scale showing how acid or alkaline
a substance is.
What is erosion?
• Dental erosion is the loss of plaque free tooth by
frequent acid attack.
• It can cause sensitivity to hot or cold or even
cause the tips of teeth to chip away!
Where do we find acids?
• Acids are found in many foods & drinks.
• They add to the taste & also act as a
preservative.
• Acids soften the enamel surface of the
teeth & over time this can be chipped or
worn away.
• Most drinks contain acids but some are
more harmful to teeth than others.
Measuring acidity
• The level of acidity of a substance is measured
by the PH scale from 0 - 14.
• A substance measuring 7 = neutral
• A substance measuring <7 = acid
• A substance measuring >7 = alkaline
Acid and teeth:
• A drink becomes harmful to teeth when the
PH is below 5.5.
• Below 5.5, the enamel is softened and teeth
are under attack.
What drinks are most harmful to teeth?
Litmus Paper Test Activity:
• There are six different drinks to test.
• Can you decide which is most harmful & which is
least harmful?
• Make your predictions on your activity sheet.
• Test the drinks using litmus paper & the PH scale.
• Compare the results with your predictions.
Acidity of drinks:
Type of Drink
Acidity
Type of Drink
Acidity
Plain Water
Ph 7.00
Apple Juice
Ph 3.49
Milk
Ph 6.76
Blackcurrant Squash
Ph 3.19
Fizzy Water
Ph 4.72
Fruit Tea
Ph 2.98-3.95
Diet Cola
Ph 4.61
Low Calorie squashes
Ph 3.0-3.2
Orange Juice
Ph 3.84
Still flavoured Water
Ph 2.84
Lemon Squash
Ph 3.56
Cola
Ph 2.63-2.49
Your results will be similar to these…
Frequency of drinks (1):
• The amount you drink and how often affects
the amount the acid attacks the enamel.
• The longer or more often the acid is in
contact with your teeth, the longer it takes
your saliva to neutralize the acid and return
your mouth to a safe PH of 7.4
Frequency of drinks (2):
• Sipping an acidic drink throughout the day
means your teeth are bathed in acid for longer
than if you finish the drink in one go.
• It takes saliva between 30 minutes and 2 hours
to neutralize an acid attack.
Diet Analysis:
Diet Analysis Activity:
• From your diet sheet, mark on the clock face
each time you had a drink.
• Colour in a 30 minute segment from the time you
had an erosive drink
• Add up the amount of time each day that your
teeth were under attack from acid.
• How well did you do?
How to reduce the risk of erosion (1):
• Frequent soft drinks should be avoided but
if you do have one, drink it with a meal.
• Drink more water and milk or choose the
least acidic drink.
• Use a straw when drinking an acidic drink.
It reduces the contact between the acid
and your teeth.
• Do not ‘swish’ the drink or hold it in your
mouth.
How to reduce the risk of erosion (2):
• Chew sugar free gum – this increases the
saliva and speeds up neutralization.
• Or rinse your mouth with water after an
acid attack as the water washes the acid
from the teeth.
• Avoid acidic drinks before bed or through
the night as this is when the amount of
saliva is at its lowest and damage could
occur.
How to reduce the risk of erosion (3):
• Try to avoid brushing your teeth immediately
after an acid attack.
• This is when the enamel is at its softest and
you could wear some of the enamel away.
• If you must brush, rinse your mouth with water
first.
What have we learnt?
• What is dental erosion?
• Wearing away of enamel by acid attack
• What drinks cause erosion?
• Anything with a Ph below 5.5.
• What drinks are safe?
• Milk and water are the only safe drinks!
• How can erosion be prevented?
• Avoid acidic drinks
• Drink through a straw
• Don’t ‘swish’ drink around in your mouth
• Drink more water and milk
Does anyone have any
questions…?