Just what is plaque and what can happen to your teeth if you don't remove it?
Objectives:
Students will
learn the scientific method, including the concepts of observation,
hypothesis and experimentation.
Students will
observe the effects of decay and the need for good oral hygiene
will be reinforced.
Materials:
Apple
Knife (for teacher's
use only)
Paper bag
Science journals
Pencils
Preparation on first day:
Before class,
cut a hole into the apple the diameter of a quarter (or one-inch)
and about one-inch deep.
Have paper bag
out and ready for use during lesson.
Instruction for first day:
1.
Tell students that
you are starting a science lesson that will run for
several days about teeth and plaque.
2.
Ask them to make their
best guess at what would happen if they didn't brush
their teeth and instead let plaque accumulate. Explain
that when a scientist makes his or her best guess it
is called a hypothesis. In order to test if a hypothesis
is correct, scientists conduct an experiment.
3.
Tell the students
that the experiment begins by making observations, and
hold up the apple and allow them to see it. (You may
want to prepare several apples and have the class break
into smaller groups, each group with their own apple).
4.
Give the students
time to record their observations in their science journals
or on paper by drawing a picture or writing a sentence.
5.
Allow them to share
their observations with a partner, in groups or whole
class.
6.
Explain that you
will put the apple in a paper bag for a few days and
then they will reexamine it.
7.
Have the students
now record their hypotheses about what the apple will
look like the next time they observe it.
Instruction for follow-up day:
1.
Ask students to recall
the first day observations and share. Now have them
share their hypotheses about the condition of the apple
now.
2.
Remove the apple from
the paper bag and allow the students time to observe
it and record their observation in their journals and
with each other.
3.
Next cut the apple
in half through the original hole and let the students
observe the cross-section and have them record and share
their findings.
4.
Explain that this
is an example of decay, which happens to teeth when
they are not properly brushed and flossed. Plaque is
a layer of sticky bacteria that can build up on tooth
surfaces. The bacteria release acids, which weaken the
teeth and cause decay, or cavities. Brushing and flossing
will remove the plaque and help prevent tooth decay.
You also need to eat healthy foods like cheese, milk
and vegetables and visit the dentist twice a year for
a check-up. Avoid candy and sticky food with sugar.
If you eat sweets, make sure that you brush afterwards
to keep your teeth health and not looking like the apple!
Extentions:
Math
Classroom
brushing and flossing graph:
Have students
begin a brushing and flossing journal to record their
"homework." They should record the number of times they
brushed and flossed. (See handouts:
master 1)
Everyday
the students bring their brushing and flossing journal
in and are instructed to color 1" squares of graph paper
for each time they brushed their teeth the day before
and write their names on the pieces. Then they cut them
out and glue them to a class graph showing the total
number of times the children in the room brushed their
teeth on that day. They do the same thing for flossing.
At the end of the week, they can see all the great work
they did to promote their dental health.
Language
Arts
Have students
write a brochure to share with another class or their
families about the importance of brushing and flossing.
They can use the experiment with the apple to demonstrate
what could happen if plaque is not properly removed.
