TOPIC FOR DISSERTATION
COMPARATIVE EVALUATION OF THE MECHANICAL
PROPERTIES OF FOUR ORTHODONTIC ALIGNER MATERIALSAN IN-VITRO DESCRIPTIVE STUDY
M. A. RANGOONWALA COLLEGE OF DENTAL SCIENCES AND RESEARCH CENTRE
AZAM CAMPUS, PUNE - 411001.
DEPARTMENT OF ORTHODONTICS AND DENTOFACIAL ORTHOPAEDICS
SYNOPSIS
ON
COMPARATIVE EVALUATION OF THE MECHANICAL PROPERTIES OF FOUR
DIFFERENT ORTHODONTIC ALIGNER MATERIALS - AN IN VITRO DESCRIPTIVE
STUDY
NAME OF THE P.G. STUDENT
NAME OF THE P.G. GUIDE
DR. FARHEEN AYAZ DALVI
DR. NASIM MIRDEHGHAN
TOPIC FOR DISSERTATION
COMPARATIVE EVALUATION OF THE MECHANICAL PROPERTIES OF FOUR
DIFFERENT ORTHODONTIC ALIGNER MATERIALS - AN IN VITRO DESCRIPTIVE
STUDY
SUBMITTED FOR PARTIAL FULFILLMENT FOR THE DEGREE OF
MDS [ORTHODONTICS AND DENTOFACIAL ORTHOPAEDICS]
OF
MAHARASHTRA UNIVERSITY OF HEALTH SCIENCES, NASHIK
BY
DR. FARHEEN AYAZ DALVI
PG STUDENT
(2019-2022)
M. A. RANGOONWALA COLLEGE OF DENTAL SCIENCES AND RESEARCH CENTRE,
PUNE – 411001
GUIDE
DR. NASIM MIRDEHGHAN
(READER, DEPARTMENT OF ORTHODONTICS AND DENTOFACIAL ORTHOPAEDICS)
From,
Dr. Farheen Ayaz Dalvi 1st Year Post-Graduate student
Department of Orthodontics and Dentofacial Orthopaedics,
M.A. Rangoonwala College of Dental Sciences and Research Centre
Pune- 411001
To,
The Registrar,
Maharashtra University of Health Sciences,
Nashik
SUBJECT: TOPIC FOR DISSERTATION: MDS (ORTHODONTICS AND DENTOFACIAL
ORTHOPAEDICS)
Respected Sir,
I have registered my name with your esteemed university in 2019 for MDS (Orthodontics and
Dentofacial Orthopaedics) under guidance of Dr. Nasim Mirdehghan (Reader, Department of
Orthodontics and Dentofacial Orthopaedics) M.A. Rangoonwala College of Dental Sciences and
Research Centre, Pune.
The suggested topic of my dissertation is as under – COMPARATIVE EVALUATION OF THE
MECHANICAL PROPERTIES OF FOUR DIFFERENT ORTHODONTIC ALIGNER
MATERIALS - AN IN VITRO DESCRIPTIVE STUDY
It is requested that necessary approval for the topic may be given.
Thanking you,
Date:
Yours Faithfully,
Dr.Farheen Ayaz Dalvi
Remarks of the Postgraduate Guide
Recommended and forwarded for approval.
Dr. Nasim Mirdehghan
Reader,
Department of Orthodontics and Dentofacial Orthopaedics,
M. A. Rangoonwala College of Dental Sciences and Research Centre, Pune.
Date:
Remarks of the Professor and Head of Department
Recommended and forwarded for approval.
Dr. Ajit Kalia
Professor and H.O.D,
Department of Orthodontics and Dentofacial Orthopaedics,
M. A. Rangoonwala College of Dental Sciences and Research Centre, Pune.
Date:
Title
COMPARATIVE EVALUATION OF THE MECHANICAL PROPERTIES OF FOUR
DIFFERENT ORTHODONTIC ALIGNER MATERIALS - AN IN VITRO DESCRIPTIVE
STUDY
Introduction
Rationale Of Study:
The increasing demand of esthetics and advancement in the technology of computer aided
design and computer manufacturing techniques has gradually evolved to bring in picture the
invisible orthodontic treatment i.e. clear aligners.1
Other than esthetic, invisible aligners have other advantage to conventional orthodontic
treatment that they are lesser prone to cavities than conventional treatment because they do
not permit better maintenance of oral hygiene. Invisible aligners are esthetically pleasing, easy
to use and has been meeting the requirements demanded by increasing number of adult
patients.1
Mechanical properties of aligners thermoplastic resin material play a very important role in
developing continuous orthodontic force to obtain desired results. The orthodontic
thermoplastic resin material should have better transparency, low stiffness, good elasticity and
resilience and resistance to aging.2
The first marked aligner material which was a polymer mixture used earlier before September
2001 by Invisalign(Align Technology, San Jose) was Proceed 30(PC30), but they did not bring
significant results for orthodontic tooth movement.2
In 2013, Invisalign aligners then made use of polymer material Exceed 30 containing
polyurethane methylene diphenyldi-isocynate 1,6 hexanediol. They had better elastic
properties 1.5 times greater than PC30 which made patient compliance better for removal and
insertion.3
After 2013 EX 30 has now been replaced by Smart Track (LD 30) a multilayer aromatic
thermoplastic polyurethane/polycoester,which provides a better and more perpetual force
over a longer period of time with better attachment to the teeth with improved elastic
properties.3
The chiefly used aligner material by manufacturer now a days is PET-G, but polypropylene,
polycarbonate, and thermoplastic polyurethane, ethylene vinyl acetate is also used. 4
Research Question:
Not Applicable.
Hypothesis:
Not Applicable.
Aim
Objective
To compare the yield strength of different orthodontic aligner materials
To compare the stress release properties of different orthodontic aligner materials.
To compare the stiffness of different orthodontic aligner materials.
To compare the elongation at peak of different orthodontic aligner materials.
To compare the flexural strength of different orthodontic aligner materials.
Review Of Literature
1. F. Elkholy ,S. Schmidt, M. Amirkhani5 (2019) conducted a study to determine different
parameters which can be used as future guidance for thermoplastic aligner material.
The specimens of PET-G of different thickness are used in this study. Both the raw
thermoplastic sheets and sheets after thermoforming with different geometrical forms
are evaluated. By using a span length of 8mm and 16mm and and deflection range of
about 0.1-0.2mm three point bending test is performed. The influence of water storage
on the bending forces was studied using loaded and unloaded specimens of the aligner
materials. A bean cantilever mathematical model was used to determine the results.
The results showed that after 24 hours immersion in water of a constant loaded sample
there was decrease in the bending force by 50%. Hence the study concluded that during
orthodontic aligner treatment very small bending deflections are combined with very
small distance between the aligner material and the tooth surface. The three point
bending test concluded that the material stress should range between 14 to 18MPa.
2. Alexandra K. Papadopoulou , Aurelie Cantele6 (2019) conducted a study to evaluate
the change in roughness and mechanical properties of Invisalign after one or two week
of use. Forty aligners along with the attachment were collected after the end of
orthodontic treatment. From which 10 were unused Invisalign used as a control
group(c), 20 had been used for one week(1w) and remaining 20 had been used for 2
weeks(2w). The same number of attachments were also cut of the from the aligner
groups(1w,2w,c) and Sa, Sq, Sz, Sc, and Sv roughness parameters of the internal surface
of the aligner attachment area and the opposite lingual side was evaluated using optical
profilometry. To evaluate the Martin hardness, indentation modulus and relaxation
index Instrumented indentation testing (IIT) was performed. They concluded there
observed to be significant decrease in the aligner roughness after 1 week of use and
there may also be decrease in the coefficient of friction there by affecting the
mechanical retention of the aligner. Hence concluded that intraoral aging has a
detrimental effect on the surface roughness properties and mechanical properties of
Invisalign.
3. Roberta CONDO, Luca PAZZINI, Loredana CERRONI3 (2018) conducted a study to
examine mechanical properties of two different thermoplastic polymer orthodontic
aligners when worn by the patient intraorally. 40 aligners were randomly selected i.e 20
LD30, 20EX30which were worn by the patients for 22 hours per day for about 2 weeks.
From every aligners 10 specimens were taken from the buccal surface of incisors which
were of 5*5 mm dimension under a stereomicroscope. All collected samples where then
subjected to Fourier transform infrared spectroscopy, micro-Raman spectroscopy, X-ray
diffraction, tensile and indentation strength test. They concluded that LD 30 to be more
homogeneous exhibiting better elastic properties and lesser tendency to tear than Ex30,
they also concluded that LD 30 has better fit and adaptation to the dental arch and also
provided a constant orthodontic force than EX30. But both LD30 and EX 30 exhibited
increased stiffness and hyperplasticity.
4. Jeong-Hyun Ryu, Jae-Sung Kwon, Heng Bo Jiang7 (2018) conducted to study the impact
of thermoforming procedure on the physical and mechanical properties of
thermoplastic material used in the manufacturing of clear aligners. Four materials were
used in this study i.e Duran, Essix A+, eClinger, Essix ACE. The transparency of 0.5mm,
0.75mm and 1mm thickness of Duran and Essix A+ decreased greatly after
thermoforming whereas, no significant difference in the values were observed for
eClinger and Essix ACE. The water absorption ability was observed to be highest for
eClinger before thermoforming whereas after thermoforming the highest values
observed was for Duran. The stiffness of all four materials exhibited no significant
difference before thermoforming whereas after thermoforming, stiffness of eClinger
was observed to be the highest compared to Essix A+ and Essix ACE. The flexural
modulus also increased significantly after thermoforming. Thus the study concluded
that the physical and mechanical properties of thermoplastic materials used for the
manufacturing of clear aligners should be examined later after thermoforming to define
their properties for the clinical use.
5. Sandro BARONE, Alessandro PAOLI, Paolo NERI2 (2017)conducted a study examining
the thermoplastic material for the mechanical and geometrical properties.10 specimens
of 3 materials of diameter of 125mm and thickness of 0.75-1mm were taken for the
tensile test. The test was performed using Instron universal testing machine 5500R
maintained at 23°C.Two test were performed to establish elastic modulus and tensile
yield stress. The testing speed was 0.1 mm/min to collect data for elastic modulus and 5
mm/min for tensile yield stress. The results obtained shows that there in only minimal
decrease in the elastic modulus expect for material 3 where the decrease in elastic
modulus is about 30% while very similar values for obtained for tensile yield stress. They
concluded that the mechanical properties of the thermoplastic aligner materials is of
great concern to determine the success of future orthodontic treatment.
6. Luca Lombardo ; Elisa Martines ; Valentina Mazzanti4 (2016) conducted a study on
stress relaxation properties of four thermoplastic orthodontic aligner materials when
undergone continuous 24 hours of deflection. They concluded that all 4 different
polymers viewed a sufficient amount of stress release during the 24 hour study period.
Stress release was significantly greater during the initial 8 hours and further maintained
a plateau phase which remained constant. The single layer F22 Aligner polyurethrane
and Duran polyethelene terephthalate glycol modified displayed a greater values for
both the stress and stress decay and the double layer Ercoloc-Pro and Durasoft
displayed a constant release of stress. They concluded that thermoplastic resin aligner
performance is mainly affected by material by which it is made up of. Stress release,
which exceeds 50% of the initial stress value in the initial hours of use, may cause great
changes in the behavior of the polymers at 24 hours from the application of orthodontic
force, which may affect programmed tooth movement.
7. Yan Song MA , Dong Yu FANG , Ning ZHANG1 (2016) conducted a study to evaluate the
tensile strength after blending, to establish a definite blending ratio for new
thermoplastic material and to evaluate its mechanical properties with commercial
available thermoplastic materials. PET-G and PC2858 were blended in 5 different
proportions to evaluate their mechanical properties. The study concludezd that, as the
amount of PC2858 increases the tensile strength and impact strength also increases but
elongation at break decreases. At a proportion of 70/30(PET-G/PC2858) the material
displayed an optimal mechanical performance, with a tensile strength of 63.42 ± 1.67
MPa and stress relaxation of 0.0080 ± 0.0005 N/s.
8. Mingdong Liu, Xuejia Ding, Yuxing Bai8 (2015) conducted a study comparing the
properties of three different thermoplastic material used in aligner therapy. The three
materials used were thermoplastic polyurethane (TPU), polycarbonate(PC) and poly
ethylene terephthalate modified glycol(PET-G) .The study was carried out at 23°C, the
transmittance and haze of all the 3 materials of a thickness of 0.8mm were tested also
the amount of saliva absorbed by the material, yeild strength, elongation at break and
elastic modulus were measure before the orthodontic treatment and after when the
material were stored at 37°C artificial saliva for two weeks. The study concluded
transmittance of all three thermoplastic materials is more than 80% and haze is less
than 0.3% and hence all 3 materials meet the condition of transparency required for
clear aligner therapy. The weight of saliva absorption increases for all the 3 materials of
which the TPU is the highest. TPU is considered as the best material when compared to
the other 2 materials as the yeild strength of TPU is the highest of all the three and
elastic modulus is the lowest. It also has highest elongation break and highest stiffness
among the three included in this study.
9. M. Iijima9 (2015) conducted a study to evaluate the effect of change in temperature and
stress loading on mechanical and shape memory properties of thermoplastic aligner
materials. 5 thermoplastic material with different glass transition temperature were
selected. The glass transition and crystal structure were examined by scanning
calorimetry and X-ray diffraction. The deteoriation of mechanical properties by thermal
cycling and orthodontic force during step wise temperature changes were investigated
using nanoindentation test and custom made force measuring system. The mechanical
properties are evaluated by three point bending test and shape recovery by heating.
They concluded that the mechanical properties of all materials decreased significantly by
2500 cycles. The polyurethane polymers showed good shape memory effect within the
range of intraoral temperature. The orthodontic force produced by aligners decreased
with stepwise temperature changes for all the materials.
10. Luca Lombardo , Angela Arreghini , Roberta Maccarrone10 (2015) conducted to evaluate
and compare the absorbance and transmittance values. Nine samples by different
manufacturers were taken in this study and all were subjected to spectrometry test for
evaluating transmittance and absorbance. The samples were subjected continuous in a
constant temperature of artificial saliva at 37°C for two cycles for 14 days. All the sample
tested viewed a low transmittance value and high absorbance value after aging and F22
aligner from all the 9 samples was found to be the most transparent both before and
after aging. The study concluded that different aligner material has different optical
properties hence depict variation in esthetic.
11. Federica Ercoli, Michele Tepedino, Vincenzo Parziale11 (2014) conducted a study
comparing two different clear aligner system. The two system used here are the
‘Nuvola®’ system and ‘Fantasmino®’ system to evaluate and compare the properties and
indication for use in different cases. They conluded that the two types of aligner system
showed significant difference. Fantasmino system has better elastic properties buts its
size does not provide good support throughout the day. Nuvola system provides better
tooth movement and its size facilitates the patient’s collaboration. They also concluded
that there were difficulties seen in correction of torque and rotation in both the system.
12. Dongyu FANG, Ning ZHANG, Hui CHEN12 (2013) conducted a study to examine the
dynamic stress relaxation of thermoplastic aligner material by Bose Electron Force along
with homemade temperature controlled water bath. A 3hourstress relaxation curves
was measured for 5 orthodontic thermoplastic material at 37°C and comparison was
done with atmospheric temperature. Stress at 0, 30, 60, 90, 120, 150, and 180 min was
recorded. They concluded that residual stress of all 5 thermoplastic orthodontic
materials decreases as the time passes and the same process accelerates at 37°C. Based
on this study done in a oral environment at 37°C , Masel and Erkodur are significantly
less affected among all the other five materials, and also showing a slower stress
relaxation rate with time in the aging environment than the other three materials.
13. Naohisa Kohda, Masahiro Iijima, Takeshi Muguruma13 (2012) conducted a study the
effects of mechanical properties, the thickness of material, and amount of activation on
orthodontic force they also investigated force delivery of thermoplastic materials. Three
thermoplastic materials i.e Duran (Scheu Dental), Erkodur (Erkodent Erich Kopp GmbH),
and Hardcast (Scheu Dental) of two different thickness were evaluated by
nanoindentation method to determine surface hardness and elastic modulus. The study
concluded that Hardcast had lowest elastic modulus and hardness than Duran and
Erkodur, aligners fabricated by thicker materials provide greater force when compared
to thinner materials Aligners when activated by 1.0mm produced lower force than those
with 0.5 mm. A strong relation is observed between the mechanical properties and
orthodontic force.
14. Jae-Sung Kwon, Yong-Keun Lee, Bum-Soon Lim14 (2008) conducted a study to determine
the force delivery and resilience delivery properties of the thermoplastic materials use in
orthodontics and to also observe the change in force delivery properties after repeated
loading or after the thermoforming procedure. 3 materials of 3 different thickness are
taken in this study. Three point bending test was performed before and after
thermocycling. The materials were thermocycled for 1000 cycles or repeatedly deflected
by 1mm for 100 cycles. Vickers hardness test was performed to evaluate the change
after thermocycling or repeated loading cycles. They concluded that the amount of
deflection for optimal force was about 0.2-0.5mm. Thermocycling and repeated loading
significantly affected the Vickers hardness number. They further concluded that the thin
material of about 0.508mm can deliver more higher energy when compared to the thick
material of about 0.762 or 1.016mm of the same brand. Hence thin material should be
of concern for orthodontic tooth movement of the same brand.
15. Hiromi Ryokawa, Yoshikazu Miyazaki, Akihiro Fujishima15 (2006) conducted a study to
evaluate the mechanical properties of thermoplastic material used in dentistry at a
controlled oral temperature of 37°C 8 thermoplastic material i.e EVA (Bioplast),
PE(Copyplast), PETG (Duran), PP (Hardcast), PC (Imprelon‘‘S’’), A+ (Essix A+), C+ (Essix
C+), and PUR(Invisalign) were examined under week water absorption test, change in
thickness when the material is thermoformed along with water absorption test, tensile
test under room temperature and at a controlled oral environment. The study
concluded that the water absorption increases with the increase in time and the lowest
to the highest order is PE,C,PP,EVA,PC,A+,PETG,PUR, the range of change in the
thickness is 74.9-92.6% while comparing and before thermoforming. The range for
water absorption is 100.3 to 119.9%. There was significant increase in the elastic
modulus of PET-G,PC and A+ when maintained at a controlled oral environment
whereas the elastic modulus of PP,C+CP and EVA significantly reduced. No changes were
observed for PUR. The tensile yield strength of all the materials maintained at a
controlled oral environment significantly decreased when compared to the original
sheets. The study further concluded that the mechanical properties of thermoplastic
material used in dentistry varied on the change in environmental temperature. The
application of thermoplastic materials for orthodontic tooth movement requires a
sufficient understanding of the material characteristics, optimal material selection, and
design.
Methodology
Study Design: An in-vitro descriptive study
Study Setting: This is an in-vitro study will be conducted to compare the mechanical properties
of different orthodontic aligner materials
Study Population: Not applicable
Sample Size: 4 commercial orthodontic aligner materials
Materials: Commercial Indian orthodontic aligner materials
Universal testing machine(UTM)
Methods:
Three point bending test:
Rectangular samples (25x50 mm) of each material will be cut.
To evaluate check the dimensions and uniformity of each sample a digital guage is used at three
different points.
The four materials will further be subjected to a three-point bending test, using an Universal
Testing Machine (UTM).
Each sample will be positioned on a stainless steel stand featuring a rectangular base and two
equidistant vertical support.
After preloading , a load–deflection test is performed on each sample with the specimen being
deformed.
The resulting data were recorded and the will be used to create a load–deflection curve for
each sample.
The following formulae were used to calculate, respectively, yield strength, stiffness, elongation
at peak and flexural strength of each sample:
ε=6hδ/L2
σ =3/2xFL/Sh2
where ε strain (adimensional), h= sample thickness (mm), S=sample width (mm), L=span (mm),
F=load (N), δ=deflection (mm) and σ =stress (MPa).
Stress relaxation test:
Each material is stretched to a 5% strain of the initial length and
the initial force N0 will be recorded by the universal testing
machine. The strain is then maintained allowing the force to
recover within 1 hour The remaining force N1 will then be
recorded after 1 hour. The stress relaxation rate (N/s) was
calculated
Formulae(NO-N1)/3600
Data analysis plan and methods: Descriptive statistical measures
will be used to summarize the data on various mechanical
properties studied. Being a descriptive study no statistical
comparison will be made across the samples to be studied.
Reference of drug/procedure: Not applicable
Reference of disease: Not applicable
Drug formulation details: Not applicable
Randomization: Not applicable
Blinding: Not applicable
Reference of disease: Not applicable
Treatment details: Not applicable
Allocation concealment: Not applicable
Explained intervention in required details: Not applicable
References:
1. Yan Song MA, FANG DY, ZHANG N, DING XJ, ZHANG KY, BAI YX.
Mechanical Properties of Orthodontic Thermoplastics
PETG/PC2858 after Blending. Chin J Dent Res. 2016;19(1):43-8.
2.Barone S, Paoli A, Paolo NE, Razionale AV, Giannese M.
Mechanical and geometrical properties assessment of
thermoplastic materials for biomedical application. InAdvances
on Mechanics, Design Engineering and Manufacturing 2017 (pp.
437-446). Springer, Cham.
3.PAZZINI L, CERRONI L, PASQUANTONIO G, PECORA A, MUSSI V,
RINALDI A, MECHERI B, LICOCCIA S, MAIOLO L. Mechanical
properties of “two generations” of teeth aligners: Change analysis
during oral permanence. Dental materials journal. 2018 Sep
27;37(5):835-42.
4.Lombardo L, Martines E, Mazzanti V, Arreghini A, Mollica F,
Siciliani G. Stress relaxation properties of four orthodontic aligner
materials: a 24-hour in vitro study. The Angle Orthodontist. 2016
Jan;87(1):11-8.
5. Elkholy F, Schmidt S, Amirkhani M, Schmidt F, Lapatki BG.
Mechanical Characterization of Thermoplastic Aligner Materials:
Recommendations for Test Parameter Standardization. Journal of
Healthcare Engineering. 2019;2019.
6. Papadopoulou AK, Cantele A, Polychronis G, Zinelis S, Eliades T.
Changes in Roughness and Mechanical Properties of Invisalign®
Appliances after One-and Two-Weeks Use. Materials. 2019
Jan;12(15):2406.
7. Ryu JH, Kwon JS, Jiang HB, Cha JY, Kim KM. Effects of
thermoforming on the physical and mechanical properties of
thermoplastic materials for transparent orthodontic aligners. The
Korean Journal of Orthodontics. 2018 Sep 1;48(5):316-25.
8. Mingdong Liu, Xuejia Ding, Yuxing Bai, Dongyu Fang. The Study
of the Properties of Three Kinds of Thermoplastic Material for
Invisible Bracketless Appliance. American Journal of Chemistry
and Application. Vol. 2, No. 4, 2015, pp. 57-60.
9. Iijima M, Kohda N, Kawaguchi K, Muguruma T, Ohta M,
Naganishi A, Murakami T, Mizoguchi I. Effects of temperature
changes and stress loading on the mechanical and shape memory
properties of thermoplastic materials with different glass
transition behaviours and crystal structures. European journal of
orthodontics. 2015 Mar 18;37(6):665-70.
10. Lombardo L, Arreghini A, Maccarrone R, Bianchi A, Scalia S,
Siciliani G. Optical properties of orthodontic aligners—
spectrophotometry analysis of three types before and after aging.
Progress in orthodontics. 2015 Dec;16(1):41.
11. Ercoli F, Tepedino M, Parziale V, Luzi C. A comparative study
of two different clear aligner systems. Progress in orthodontics.
2014 Dec;15(1):31.
12. Fang D, Zhang N, Chen H, Bai Y. Dynamic stress relaxation of
orthodontic thermoplastic materials in a simulated oral
environment. Dental materials journal. 2013 Nov 28.
13. Kohda N, Iijima M, Muguruma T, Brantley WA, Ahluwalia KS,
Mizoguchi I. Effects of mechanical properties of thermoplastic
materials on the initial force of thermoplastic appliances. The
Angle Orthodontist. 2012 Oct 4;83(3):476-83.
14. Kwon JS, Lee YK, Lim BS, Lim YK. Force delivery properties of
thermoplastic orthodontic materials. American Journal of
Orthodontics and Dentofacial Orthopedics. 2008 Feb
1;133(2):228-34.
15. Ryokawa H, Miyazaki Y, Fujishima A, Miyazaki T, Maki K. The
mechanical properties of dental thermoplastic materials in a
simulated intraoral environment. Orthodontic waves. 2006 Jun
1;65(2):64-72.
Timeline/ Gantt chart:
Months
1-3
4-6
7-9
10-12
13-15
16
17
18
Protocol Preparation
and Submission
Ethical Clearance
Submission of
synopsis
to MUHS
Testing, Data entry
and
analysis
Dissertation Writing
Submission to MUHS
Annexure:
1-3 Months
4-6 Months
7–9 Months
10–12
Months
13–15
Months
16th Month
Sample recruitment, Data Collection and Entry
Sample Recruitment, Data Collection and Entry, Revaluation / Followup
Sample Recruitment, Data Collection and Entry, Revaluation / Followup
Data Collection and Entry, Revaluation / Follow-up, Data Analysis
Data Collection and Entry, Revaluation / Follow-up, Data Analysis
Data Collection and Entry, Revaluation / Follow-up, Data Analysis,
Finding conclusion & Discussion, Dissertation writing and proof
reading
17th Month
Dissertation writing and proof reading
18th Month
Thesis submission
PROFORMA FOR SUBMITTING DISSERTATION SYNOPSIS TO THE ETHICAL
COMMITTEE
M.A.RANGOONWALA COLLEGE OF DENTAL SCIENCES AND RESEARCH
CENTRE,PUNE – 411001
1
Discipline:
2
Title of the Dissertation
3
Name and Designation of :
ORTHODONTICS AND DENTOFACIAL ORTHOPAEDICS
a) PG Student
DR. FARHEEN AYAZ DALVI
b) PG Guide
4
Duration of Project
a) Period for collection of
data
b) Dead line for collection
of data
c) Period that may be
required for analyzing the
data
DR. NASIM MIRDEHGHAN
READER , DEPARTMENT OF ORTHODONTICS AND
DENTOFACIAL ORTHOPAEDICS
18 months
1 year
June 2021
3 months
5
Materials And Methods
Study Design: An in-vitro descriptive study
Study Setting: This is an in-vitro study will be conducted
to compare the mechanical properties of different
orthodontic aligner materials
Study Population: Not applicable
Sample Size: 4 commercial orthodontic aligner materials
Materials: Commercial Indian orthodontic aligner
materials
Universal testing machine(UTM)
Methods:
Three point bending test:
Rectangular samples (25x50 mm) of each material will be
cut.
To evaluate the dimensions and uniformity of each
sample a digital guage is used at three different points.
The four materials will further be subjected to a threepoint bending test, using an Universal Testing Machine
(UTM).
Each sample will be positioned on a stainless steel stand
featuring a rectangular base and two equidistant vertical
support.
After preloading , a load–deflection test is performed on
each sample with the specimen being deformed.
The resulting data were recorded and the will be used to
create a load–deflection curve for each sample.
The following formulae were used to calculate,
respectively, yield strength, stiffness, elongation at peak
and flexural strength of each sample:
ε=6hδ/L2
σ =3/2xFL/Sh2
where ε strain (adimensional), h= sample thickness (mm),
S=sample width (mm), L=span (mm), F=load (N),
δ=deflection (mm) and σ =stress (MPa).
Stress relaxation test:
Each material is stretched to a 5% strain of the initial length and
the initial force N0 will be recorded by the universal testing
machine. The strain is then maintained allowing the force to
recover within 1 hour The remaining force N1 will then be
recorded after 1 hour. The stress relaxation rate (N/s) was
calculated
Formulae(NO-N1)/3600
Data analysis plan and methods: Descriptive statistical measures
will be used to summarize the data on various mechanical
properties studied. Being a descriptive study no statistical
comparison will be made across the samples to be studied.
Reference of drug/procedure: Not applicable
Reference of disease: Not applicable
Drug formulation details: Not applicable
Randomization: Not applicable
Blinding: Not applicable
Reference of disease: Not applicable
Treatment details: Not applicable
Allocation concealment: Not applicable
Explained intervention in required details: Not applicable
6
Deadline for submission
of dissertation to the
University
7. Review of progress of the dissertation:
1st Quarter
Review of progress of
dissertation
Review of collected data
Review of analysed data
2nd Quarter
3rd Quarter
Final
8. Administrative & ethical issues
(a) Is the infrastructure facility required for the conduct of the
YES
dissertation available in the institution and affiliated hospital?
(b) Is the necessary support from various other Specialties required
for the dissertation available?
YES
(c) Does the Project involve any drug trial on animals?
If so, Does the facility for animal house exist in or around the Unit?
NO
(d) Does the Project involve any drug trial on human beings,
If so clarify.
NO
Are the human subjects available in or near the unit and have you
discussed the matter with the concerned administrative authorities ?
(e) Have you obtained clearance from the Institutional Ethical
YES
Committee?
(f) Do you consider the proposed number of subjects will be
available within the proposed period of study and will be adequate to
make the study result oriented?
NA
9. The topic was discussed and approved in the departmental
YES
meeting.
10. Signature of
PG Student
:
Dr. FARHEEN DALVI
PG Guide
:
Dr. NASIM MIRDEHGHAN
READER,
Department of ORTHODONTICS AND DENTOFACIAL ORTHOPAEDICS,
M.A. Rangoonwala College ofDental sciences and research centre, Pune.
Concerned HOD
:
Dr. AJIT KALIA
Reader
Department of Orthodontics and Dentofacial Orthodpaedics,
M.A. Rangoonwala College of Dental sciences and research centre, Pune.
11.
Date of submission to the ethical committee
:
12.
Date of clearance by the Committee
:
13.
Remarks of the Secretary
:
Appendix[A]
Name of the P.G College
M.A. Rangoonwala College of Dental Sciences & Research
Centre, Pune.
Department
Orthodontics and Dentofacial Orthopaedics
Name of the Guide & College
Dr. Nasim Mirdehghan, Reader, M.A. Rangoonwala College of
Name
Dental Sciences & Research Centre, Pune.
Contact No. of the guide
+917768981100
Through Proper Channel Only
To
The Registrar,
MUHS, Nashik - 422004.
Subject: Submission of Topic of Dissertation
Respected Sir/Madam,
I, Dr. Farheen Ayaz Dalvi, registered for Post-Graduate course in Orthodontics and Dentofacial
Orthopaedics, in the 2019–2020 batch under the guidance of Dr. Nasim Mirdehghan(M.D.S),
M.A.Rangoonwala College of Dental Sciences and Research Centre, Pune.
I am due to appear for M.D.S Orthodontics in 2022.
I am submitting here with Title of Synopsis as mentioned below as suggested by my aforesaid
Guide.
TITLE OF SYNOPSIS
Comparative evaluation of the mechanical properties of different orthodontic
aligner material: An in-vitro cross-sectional study
Kindly accept and register my Title of Synopsis.
Dr. Farheen Ayaz Dalvi
(Candidate Name and signature)
The Guide is recognized as a P.G. Teacher by the university vide letter no.
Dr. Nasim Mirdehghan
Dr. Ajit Kalia
(Guide name and signature)
(HOD Name and Signature with
Dept. Seal)
Dr.Ramandeep Dugal
(Signature & seal of Dean of the college)
APPENDIX ‘B’
REPORT OF ETHICS COMMITTEE
NAME
Dr. Farheen Ayaz Dalvi
CANDIDATE ADMITTED YEAR
2019
COURSE AND SUBJECT
MDS- Orthodontics and Dentofacial
Orthopaedics
COLLEGE NAME AND ADDRESS
M. A. Rangoonwala College of Dental
Sciences and Research Centre, Pune.
REFERENCE NO:
DATE:
To,
Dr. Farheen Ayaz Dalvi
Department of Orthodontics and Dentofacial Orthopaedics
M.A. Rangoonwala College of Dental Sciences
and Research centre, Pune
Subject: Research proposal of Dr. Farheen Ayaz Dalvi entitled,
Comparative evaluation of the mechanical properties of different
orthodontic aligner material: An in-vitro cross-sectional study
Ref: -________________________________
(Letter/Proposal of Student)
Dear Student,
The above-mentioned research proposal of title of synopsis was discussed in the
ethics committee meeting held on (Date) ______________ at our college.
It is declared that—
The said Title of Synopsis is not repeated.
1. You are registered under Dr. Nasim Mirdehghan who is a University
Recognized P.G. Teacher
vide university letter no. for guidance and supervision during studies.
2. Ethics Committee has unanimously approved your Title & Synopsis of
Dissertation.
3. The Title is Recommended for study by the student from Date
Note:
1. It will be mandatory for the student to work on the University approved Title
for a
minimum period of 18 months after its approval.
2. It is the responsibility of the student and guide to inform the Ethics Committee
about
completion of the said research work (format as per annexure ‘C’).
Dr. P.M.Bulakh
Chairperson, Ethics Committee
M.A Rangoonwala College of Dental Sciences & Research Centre, Pune411001