This document discusses the use of fluoridated elastic chains in orthodontic treatment to help prevent dental caries. It summarizes several studies that found fluoridated elastic chains initially release high levels of fluoride that decrease over time, but provide continuous low-level fluoride release. While fluoride chains showed greater force degradation than conventional chains, increasing the initial extension can compensate. A clinical study found patients using fluoridated chains had less enamel decalcification compared to a control group. Stretching fluoridated chains increases the amount of fluoride released by around 7%.

1. Fluoridated Elastic Chain
Prepared by: Sohaila Ibrahim
Under Supervision of: Prof. Dr. Maher Fouda

2. Introduction
Orthdontic fixed
appliances
complicate cleaning
and make access to
plaque-retaining
areas difficult
Many authors point to
the high prevalence
of dental caries in
patients undergoing
orthodontic
treatment

3. Increasing host
resistance is one
way to prevent
demineralization
and caries and
application of
fluoride is an
accepted means of
reduction of caries
incidence during
orthodontic
treatment

4. Incorporating fluoride
ions in
elastomerics as a
source of fluoride-
release is
suggested as one
way to convey
fluoride
continuously into
saliva if there is
regular elastomeric
change during
space closing

5. Role of fluoride in caries
prevention
2 major aspects of
fluoride action are:
1- inhibition of
demineralization at
the crystal surfaces
2- enhancement of
subsurface
mineralization
resulting in
arresment or reversal
of caries lesion

6. Mode of topical fluoride
delivery
a) Water fluoridation
b) Oral rinse
containing fluoride
c) Fluoride dentrifices
d) Fluoride tablets
e) Professionally
applied fluoride
preparations

7. Orthodontic materials providing
fluoride release

8. 1- Fluoride containing etchant
Several studies
concluded that
addition of fluoride
to etchant had no
significant effect to
enamel caries
prevention or
deterioration on the
etching effect on
enamel

9. 2- Fluoride containing
cements
Polyalkenoate cements
were clinically
associated with less
demineralization than
zinc phosphate or
zinc polyacrylate
Sadowsky et al (1981)
demonstrated that
fluoride containing
cements have
preventive effect on
demineralization

10. 3- Fluoride-containing bonding
adhesives
These are glass
ionomer cements
and composite resin
An in vitro study (Valk
and Davidson,
1987) indicated that
glass ionomer
cement protected
an area of
approximately 1 mm
wide around the
orthodontic bracket

11. 4- Fluoride-releasing elastomeric
ties
An in vitro study by
Schemehom and
Farnham (1988)
showed that the
10% stannous
fluoride elastomeric
ties showed
greater
remineralization of
adjacent enamel
than the 1.4% ties

12. 5- Fluoride releasing elastic
chain
Upon stretching of
these chains, 7%
increase in fluoride
release is observed

13. Fluoride Release from
Orthodontic Elastic Chain
A study done by Joseph et al (1993) suggested
that the rate and amount of stannous fluoride
release from a fluoride-releasing power chain
was initially high (0.106 mg/hour between 6-24
hours) but dropped after 72 hours and
remained at low levels until the end of
experimental periods

14. Elastic properties of fluoride
chains
A study was
conducted to
investigate whether
or not fluoride affects
the elastic properties
in wet conditions
and dry conditions
by comparing
conventional non-
fluoride-releasing
elastic chain with
fluoride-releasing
elastic chain

15. This study revealed
that force
degradation was
more rapid in
fluoride releasing
chains than
conventional ones
The decay in wet
conditions was
greater than that of
dry conditions

16. The study suggests
that since fluoride
affects the force
degradation of the
chain, increasing the
percentage of
extension at the
commencement
might compensate
for the force loss rate
and still maintain
adequate activation
in closing spaces

17. Effectiveness of Fluoride
releasing chains
In a study on 49
patients (782 teeth)
who used fluoridated
elastic chains and
were compared with
a control group of 45
patients (740 teeth),
enamel
decalcification
incidence and
distribution were
recorded

18. In the control group,
decalcification
occurred in 73% of
patients and 26%
of all teeth while in
the group
undergoing the
experiment it
occurred in 63% of
patients and 16%
of all teeth

19. The effect of stretching on the
release of fluoride
Stretching increases the
concentration and
amount of fluoride
released
Stretched fluoridated
elastic chains release
approximately 32
gF.day/ml while the
unstretched ones
release 30 gF.day/ml.
This represents a 7%
increase in fluoride
release