Download 6.1 need for the study - Rajiv Gandhi University of Health Sciences

5. TITLE OF THE TOPIC
“EFFECTS OF MOUTHWASHES WITH AND WITHOUT BLEACHING
AGENTS AND DIFFERENT CONCENTRATIONS OF
CHLORHEXIDINE ON FORCE DECAY OF ELASTOMERIC CHAIN –
AN IN-VITRO STUDY”
6. BRIEF RESUME OF THE INTENDED STUDY:
6.1 NEED FOR THE STUDY:
Elastomeric chains are widely used in orthodontics to facilitate tooth movement and to
consolidate space. However, force decay of these materials has been a clinical problem.
A rapid loss of force causes inefficient tooth movement.
The use of mouthwashes during orthodontic treatment is recommended by orthodontist
for the maintenance of oral hygiene because presence of orthodontic appliance in the oral
cavity leads to accumulation of bacterial plaque. The patients who are unable to maintain
good oral hygiene should implement chemical plaque control. Among the antiseptics for
oral use, chlorhexidine is one of the most powerful antimicrobial agents.
Also, the presence of orthodontic appliance in the oral cavity leads to formation of stains
on the teeth. In order to remove these stains, orthodontists use various dental bleaching
techniques.
Therefore, the aim of this study is to evaluate the effect of mouthwashes with and without
bleaching agents and different concentrations of chlorhexidine on force degradation of
elastomeric chains.
6.2 REVIEW OF THE LITERATURE
1. A study conducted by Pakhan Kanchana and Keith Godfrey (2000)1 determined the
force-extension and force degradation characteristics of orthodontic latex elastics.
Orthodontic latex elastics by 4 manufacturers were subjected to static testing for
evaluation of force extension characteristic under dry condition and force degradation
under wet condition to simulate the oral environment. An Instron testing machine
(Model 4301) with load cell capacity of 100 newtons was used. For the dry test, each
elastic was stretched by continuous extension from slack condition to 60 mm. Resultant
force versus length changes was recorded. For the wet test, each elastic was stretched
to 20, 26, 32, 40mm. There were significant differences in force extension and force
degradation characteristics between different extensions and force magnitudes for the
elastics of the different manufactures.
2. A study conducted by Kyung-Ho Kim, Chun-His Chung, Kwnagchul Choy, JeongSub Lee and Robert L.Vanarsdall (2005)2, investigated effects of prestreching on force
decay of elastomeric chain. Two different modules, 5-unit (12.5mm) and 6-unit
(15.5mm) modules were prestreched 100% for 1 hour, 24 hours, 2 weeks and 4 weeks
in distilled water. The prestreched and unprestreched (control) modules were then
stretched to 30mm in 370C water and their forces were measured at zero hour, 1 hour,
24 hours and weekly for 4 weeks with a digital force gauge. The prestreched 5 and 6unit modules yielded significantly lower initial force than the controls. The effects of
prestreching on force decay of elastomeric chains were noted mainly in the 1st hour.
Thus, the clinical value of prestreching a synthetic elastomeric chain is questionable.
3. Another study done by Nora Buchmann, Christiane senn, Judith Ball, Lorenz Brauchli
(2012)3 investigated the dependence of force decay on the initial strain applied to
currently available elastic chains. Eight different elastic chains from eight major
companies were tested for force decay by using Instron 3344 over a period of three
weeks at 50% and 100% strain. At 50% strain, the % of force decay varied from 28%
to 70% with in the first 24hours, and from 37% to 75% after 21days. For all chains
combined, force decay between the different time intervals was significant for all
measurements on the first day, but was not significant for measurements between 24
hours and 21days.
4. Another study by Terrah M. Larrabee, Sean Shih-Yao Liu et al (2012; 82)4 tested the
effect of alcohol exposure on force decay of orthodontic elastomeric chain. A total of
450 specimens were divided into five test groups. Two test groups were exposed to
different alcohol concentrations (14% and 26.9%) and the other two test groups were
exposed to different commercially available mouth rinses (Cephacol-14% alcohol and
Listerine-26.9% alcohol) for 60 seconds twice a day. Control group was exposed only
to deionized water. Force measurements were taken at six time intervals (initial, 1 day,
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7 days, 14 days, 21 days and 28 days). Statistically significant effects of time on force
decay were seen in all groups. All test groups showed significantly more force decay
than the control group. They concluded that alcohol causes an increase in force decay
of elastomeric chain over time.
5. Another study conducted by Matheus Melo Pithon, Dandara Andrade Santana, Kassio
Henrique Sousa, Isa Mara Andrade Oliveria Farias et al (2013)5 evaluated the effects
of different concentrations of chlorhexidine on the decline in force of orthodontic
elastics. Five groups of samples were tested, with one control group represented by
distilled group (group 1) and four experiments groups: 0.12% manipulated
chlorhexidine (group 2), 0.2% manipulated chlorhexidine (group 3), 0.12%
chlorhexidine gluconate based oral solution (0.12% perioguard; group 4) and 0.2%
cleanform (group 5). Force was measured with a digital dynamometer at six different
time intervals 0,1,7,14,21 and 28 days. In this study, chlorhexidine showed no
significant influence on the force degradation of the elastics chain tested.
6. Another study by Matheus Melo Pithon, Ailana Cardoso Rodrigues, Erica Luiza
Santana Moreira Sousa, Lilia Paula de Souza Santos, Natalia dos Santos Soares et al
(2013)6 evaluated the effects of mouthwashes with and without bleaching on the force
of elastomeric chains. A total of 108 elastomeric chain specimens was divided into six
groups (n=18 in each group). Two test groups were exposed to two types of commonly
used mouthwashes (Plax and Listerine whitening). Immersions in the solutions was
performed twice a day for 60 seconds. One control group immersed in artificial saliva
and other control group were exposed to distilled water throughout the entire
experimental period. Force measurements were performed at six time intervals (initial,
1 day, 7 days, 14 days, 21 days, and 28 days). The presence of bleaching agent has no
influence on the force degradation of elastomeric chain.
6.3 OBJECTIVES OF THE STUDY
1. To test the effects of mouthwashes with and without bleaching agents on force
degradation of elastomeric chain.
2. To compare the effects of different concentrations of chlorhexidine mouth wash
on the force degradation of elastomeric chain.
3. To determine the force degradation of elastomeric chain by using different
mouthwashes.
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MATERIALS AND METHODS
7.1 SOURCE OF THE DATA
This in-vitro study will be done in Department of Orthodontics and Dentofacial
Orthopedics, Sri Rajiv Gandhi College Of Dental Sciences and Hospital, Bangalore.
Materials:
1. Elastomeric chain- Short spacing type.
2. Artificial saliva.
3. Mouthwashes :
a. “Listerine Whitening freshening whitening rinse” manufactured by
Johnson & Johnson Healthcare products, USA.
b. “Colgate Optic White” manufactured by Colgate-Palmolive
Company, USA.
c. “Listerine mouthwash” manufactured by Johnson & Johnson
limited, India.
d. “Colgate Plax” manufactured by Colgate-Palmolive Company,
India.
e. “Clohex Plus” manufactured by Dr.Reddy’s Laboratories limited,
India.
f. “Octowash” manufactured by Octane Biotech Private limited,
India.
Equipment’s:

Dontrix force gauge.

Stabilizing zig
7.2 METHOD OF COLLECTION OF DATA
Seven groups of samples will be tested. Each group included 12 elastomeric
chain (total n=84). The elastomeric chains to be used will be of short spacing type. For
each elastomeric chain, five links will be left free and two links will be used for fixation
on to the jigs.
The specimens will be mounted on personalized test jigs. To fabricate the
personalized jigs, PVC tubes will be used, in which small holes will be made to insert the
supporting rods for elastomeric chains. To fix the rods self-polymerizing acrylic resin will
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be injected. The holes will be separated by a mean horizontal distance of 0.5cm. On the
test set up, the elastomeric chain will be stretched along a vertical distance of 23.5mm.
This measure will be constant during the measurement. These jigs will allow the
elastomeric chain to be submerged in an artificial saliva solution throughout the
experimental period and allow immersion in the test solution as well.
Control group:
Group 1 - Elastomeric chains exposed only to artificial saliva for 28 days.
Experimental groups:
Group 2 – Elastomeric chains exposed to Listerine Whitening freshening whitening rinse.
Group 3 – Elastomeric chains exposed to Colgate Optic White rinse.
Group 4 – Elastomeric chains exposed to Listerine mouthwash.
Group 5 – Elastomeric chains exposed to Colgate Plax rinse.
Group 6 – Elastomeric chains exposed to Clohex Plus rinse.
Group 7 – Elastomeric chains exposed to Octowash rinse.
The test groups will be exposed to mouthwashes twice a day for 60
seconds each with an interval of 12 hours between one daily exposure. The test period will
be for 28 days. Force measurements will be performed at six different intervals (initial, 1,
7, 14, 21 and 28 days).
PLAN FOR DATA ANALYSIS
The statistical tests which will be used in this study are :
1. Descriptive statistical analyses, including means and standard deviations, will be
performed for the groups.
2. Analysis of variance to determine whether there will be statistical differences among
the groups and the Tukey test will be performed subsequently.
INCLUSION CRITERIA
1. Elastomeric chain – Short spacing type.
2. Chlorhexidine mouthwash -0.2% and 2%.
EXCLUSION CRITERIA
1. Elastomeric chain – long spacing and continuous type.
2. Chlorhexidine mouthwash – not more than 2%.
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7.3 DOES THE STUDY REQUIRE ANY INVESTIGATIONS OR
INTERVENTIONS TO BE CONDUCTED IN PATIENTS OR
OTHER HUMANS OR ANIMALS
No
7.4 HAS ETHICAL CLEARANCE BEEN OBTAINED FROM YOUR
INSTITUTION
Not applicable
LIST OF REFERENCES
1. Kanchana P, Godfrey k. Calibration of force extension and force degradation
characteristics of orthodontic latex elastics. Am J Orthod Dentofacial Orthop
2000;118:280-287
2. Ho Kim K, His Chung C, Choy K, Sub Lee J, Vanarsdall R L. Effects of
prestreching on force degradation of synthetic elastomeric chains. Am J Orthod
Dentofacial Orthop 2005; 128: 477- 482.
3. Buchmann N, Senn C, Ball J, Brauchli L. Influence of initial strain on the force
decay of currently available elastic chains over time. Angle Orthod.2012; 82:529535.
4. Larrabee T M, Yao Liu S S, Gorena A T, Rojas A S, Eckert G J, Stewart K
T. The effects of varying alcohol concentrations commonly found in mouth rinses
on the force decay of elastomeric chain. Angle Orthod. 2012; 82:849-899.
5. Pithon M M, Santana D A, Sousa K H, Farias I M A O. Does chlorhexidine in
different formulations interfere with the force of orthodontic elastics? Angle
Orthod. 2013; 83:313-318.
6. Pithon M M, Rodrigues A C, Sousa E L S M, Santos L P S, Soares N S. Do
mouthwashes with and without bleaching agents degrade the force of elastomeric
chains? Angle Orthod. 2013; 83:712-717.
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