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RAJIV GANDHI UNIVERSITY OF HEALTH SCIENCES
BANGALORE, KARNATAKA
ANNEXURE II
PROFORMA FOR REGISTRATION OF SUBJECT FOR
DISSERTATION
1.
NAME OF THE CANDIDATE : DR. DADU MAHAMMEDSAIM SALIMBHAI
POST GRADUATE STUDENT,
AND ADDRESS
DEPT OF ORTHODONTICS AND DENTOFACIAL
ORTHOPAEDICS,
BANGALORE INSTITUTE OF DENTAL
SCIENCES, BANGALORE-560029
2.
NAME OF THE INSTITUTION
: BANGALORE INSTITUTE OF DENTAL SCIENCES
AND HOSPITAL AND POST GRADUATE
RESEARCH CENTRE, 5/3 HOSUR MAIN ROAD,
BANGALORE-560029
3.
COURSE OF THE STUDY AND : MASTER OF DENTAL SURGERY
ORTHODONTICS & DENTOFACIAL
SUBJECT
ORTHOPAEDICS
4.
DATE
OF
ADMISSION
TO :
21/05/2012
COURSE
5.
TITLE OF THE TOPIC
A COMPARATIVE EVALUATION OF
FRICTIONAL RESISTANCE DURING SLIDING
: MOVEMENT OF DIFFERENT ARCHWIRE
MATERIALS USED WITH CONVENTIONAL
STAINLESS STEEL BRACKETS, CERAMIC
BRACKETS WITH METAL SLOT AND SELF
LIGATING BRACKETS- AN INVITRO STUDY.
6.
BRIEF RESUME OF THE INTENDED STUDY:
6.1 Need for the study:
Friction is a very important factor in clinical orthodontics that can influence almost all stages
of treatment including leveling and aligning, retraction of teeth and expression of active
torque. Overcoming the friction between the two surfaces i.e. the bracket and the archwire
demands an important consideration in appliance design, since friction opposes every action
that an orthodontist takes to move teeth. High levels of frictional forces could result in little or
no desired tooth movement, anchor loss and de-bonding of orthodontic bracket.
Understanding the frictional forces between brackets and wires is essential for achieving
adequate tooth movement and optimal biologic response.
Many studies have evaluated the variables that influence frictional resistance such as bracket
and arch wire materials, arch wire dimension, bracket slot size, torque at the wire bracket
interface, type and force of ligation, use of self- ligating brackets, inter bracket distance,
influence of oral functions and saliva.
According to previous studies on friction, stainless steel brackets are universally preferred for
their low frictional force values. Ceramic brackets were developed to improve esthetics during
orthodontic treatment but are also known for high frictional values. To combat this problem,
ceramic brackets with a metal reinforced slot have been developed. Self-ligating brackets
claim to further reduce frictional forces since it eliminates the need for any form ligation of
the archwire to the bracket.
Among the wires, stainless steel has been proven to have the lowest frictional force. Newer
grades of arch wires are known for their high resiliency, shape memory and low rigidity such
as nickel titanium and titanium molybdenum. Since these wires are required in the various
stages of treatment, it is beneficial to study the effect of friction when these wires are used in
combination with different bracket types.
The purpose of this study is to evaluate and compare the frictional forces generated by three
types of brackets (conventional stainless steel, stainless steel self- ligating and ceramic with
metal slot) in combination with three different wire alloys (stainless steel, nickel titanium and
titanium molybdenum alloy).
6.2 Review of literature:
An in vitro study1 was undertaken to evaluate the friction during sliding tooth movement in
various bracket-arch wire combinations. Four types of preadjusted maxillary premolar
brackets were used: stainless steel (Victory,3M Unitek), conventional ceramic (Transcend,3M
Unitek), ceramic with steel slot (Clarity, 3M Unitek) and stainless steel self- ligating (Damon
SL, A company). The wire alloys used were: stainless steel (Hi-T II, 3M Unitek), nickel
titanium (Nitinol, 3M Unitek) and beta titanium (TMA, Ormco). The bracket slot and wire
sized were standardized with 0.022-in and 0.019x0.025-in respectively. Frictional forces in
simulated sliding tooth movement were measured with a model that represented a clinical
condition. The model allowed tipping and rotation of teeth until contact was established
between arch wire and diagonally opposite corners of bracket wings. Each of the 12 bracket –
arch wire combinations were tested 10 times. Results showed that the pairwise differences
between conventional and self - ligating brackets and ceramic brackets with metal slots were
not significant. Conventional ceramic brackets produced higher friction than the other
brackets tested. Beta titanium wires produced higher frictional forces than nickel titanium
arch wires but no significant differences were found between each of the two and stainless
steel wires. Attempts to identify differences in surface scratches of the arch wires produced by
different brackets were unsuccessful.
An invitro study2 was conducted to evaluate friction in stainless steel and esthetic selfligating brackets with various arch wire alloys. The brackets used for the study were: stainless
steel self-ligating brackets (Damon SL II), polycarbonate self -ligating brackets (Oyster,
Gestenco) and conventional stainless steel brackets (Victory,3M Unitek). Three different
orthodontic wire alloys included : stainless steel (SS, Ormco), nickel titatnium (Ni-Ti, Ormco)
and beta titanium (TMA, Ormco). All the brackets were maxillary canine brackets with an
0.022-in slot and were tested with each type of wire alloy in three different cross sections:
0.016-in, 0.017 x 0.025-in and 0.019 x 0.025-in. Each of the 27 brackets and arch wire
combinations were tested 10 times. Both static and kinetic frictions were measured on custom
designed apparatus. Results revealed that stainless steel self -ligating bracket produced
significantly lower static and kinetic frictional forces than both conventional stainless steel
and polycarbonate self- ligating brackets, which showed no significant differences between
them. Beta titanium arch wires had higher frictional resistance than stainless steel and nickel
titanium arch wires. No significant differences were found between stainless steel and nickel
titanium arch wires. All brackets showed higher static and kinetic frictional forces as the wire
size increased. From the result, it may be concluded that in patients with high esthetic
demands, polycarbonate self-ligating brackets could be a valuable alternative to conventional
stainless steel and ceramic brackets.
An in vitro study3 was done to evaluate the magnitude of the frictional forces generated by
ceramic bracket (Transcend, 3M Unitek), ceramic brackets with metal slot (Clarity. 3M
Unitek) and stainless steel bracket (Victory series, 3M Unitek) in combination with stainless
steel, nickel titanium and beta titanium orthodontic arch wire alloys (3M Unitek). Sample size
included 30 brackets of each type (0.022-in standard edgewise canine brackets without any
built-in tip or torque) and 90 archwire segments of each wire type with a 0.019 x 0.025-in
dimension. The brackets and wires were tested with tip angulations of 0° and 10°. Friction
testing was done with Emic DL 10000 testing machine. According to the data obtained,
ceramic brackets showed the highest friction (P<0.05) followed by ceramic bracket with
metal slot and stainless steel bracket. Among the wires, beta titanium wire showed the highest
statistically significant frictional force value (P<0.05) followed by nickel titanium and
stainless steel wire. It was also observed that frictional force values were directly proportional
to the angulation increase between bracket and wire.
An in vitro study4 was done to compare the frictional forces in active and passive self –
ligating brackets with different arch wire alloys. The active self –ligating brackets used were
In-ovation (GAC,NY) and Time (American Orthodontics,Wis). The passive self- ligating
brackets were Damon SL II (Ormco, Calif) and Smart Clip (3M Unitek, Calif). A
conventional stainless steel preadjusted bracket (Gemini Series, 3M Unitek) was used as the
control. All the brackets were of the maxillary canine tooth and had an 0.022-in slot. Three
types of 0.019 x 0.025-in wire alloys used included: stainless steel, nickel titanium and beta
titanium (Sybron Dental, Ormco).Friction was evaluated in a simulated half arch fixed
appliances on a testing machine. The static and kinetic frction were anlaysed with ANOVA
and post-hoc Dencan multiple range test. Results showed that the static and kinetic frictional
forces were lower for both passive and active self-ligating brackets than for conventional
brackets. Frictional forces for active and passive self –ligating brackets with different arch
wires increased in order of stainless steel, nickel titanium and beta titanium. Intragroup
comparisons of various designs of self-ligating brackets showed no statistically significant
differences with stainless steel wire. These differences were significant when compared to
nickel titanium and beta titanium wires. It may be concluded that passive self-ligating
brackets could minimize frictional forces substantially when used with nickel titanium and
beta titanium wires.
An invitro study5
was done to investigate the static frictional resistance and surface
roughness between three types of orthodontic brackets and four different arch wire alloys. The
brackets selected for the sample were: ceramic bracket (Illusion plus, Ortho Organizers),
ceramic bracket with gold palladium slot (Virage, American Orthodontics) and stainless steel
bracket (Victory, 3M Unitek). Four arch wire alloys included: stainless steel (Permachrome,
3M Unitek), nickel- titanium (Super elastic,3M Unitek) , titanium-molybdenum alloy (Beta
III, 3M Unitek) and low friction colored TMA alloy (Ormco, Calif). Sample size included a
total of 40 brackets of each type (all 0.022-in MBT prescription canine brackets) and 30
archwire segments of each wire type (all 0.019 x 0.025-in dimension).A total of 120 bracketwire samples were tested in dry state on a universal testing machine. Surface topography of
bracket slots and arch wires were studied by using a scanning electron microscope (SEM) and
quantified by using a surface roughness testing machine (profilometer). It was observed with
ANOVA that ceramic bracket had the highest frictional force value (P<0.001) followed by
stainless steel bracket and ceramic bracket with gold palladium slot. Among the wires, TMA
wire had the highest frictional force value (P<0.001) followed by nickel titanium, colored
TMA and stainless steel wires. Frictional values of colored TMA were found to be
comparable to stainless steel wires. The results suggested that ceramic brackets with gold
palladium slot and colored TMA arch wire seem to a good alternative to stainless steel in
space closure with sliding mechanics. There was a positive correlation between bracket slot
roughness and frictional resistance but no correlation was found between wire roughness and
frictional resistance.
6.3 Objectives of the study:
1. To evaluate the kinetic frictional forces generated by three types of orthodontic brackets:
conventional stainless steel bracket, self-ligating bracket and ceramic bracket with steel
slot during sliding movement.
2. To evaluate the kinetic frictional forces generated by three types of arch wire alloys:
stainless steel, nickel-titanium and titanium-molybdenum alloy during sliding movement.
3. To compare the frictional resistance between various bracket and arch wire combinations.
7.
MATERIALS AND METHODS:
7.1 Materials:
1. Three types of 0.022-in slot maxillary canine brackets (MBT prescription) will be used:
a. Thirty conventional stainless steel brackets (Victory Series, 3M Unitek, Calif)
b. Thirty ceramic brackets with metal slot (Clarity, 3M Unitek,Calif)
c. Thirty self-ligating brackets (Smart Clip, 3M Unitek,Calif)
2. Three types of 0.019x 0.025-in dimension arch wires:
a. Nickel titanium wire (Nitinol Classic Arch wire, 3M Unitek,Calif)
b. Stainless steel wire (HI-T II , 3M Unitek,Calif)
c. Titanium molybdenum alloy (TMA, Ormco, Calif)
3. 0.010-in ligature wire ( 3M Unitek, Calif)
7.2 Method of studying:
Each of the arch wires will be cut into segments of 3-5 cms and assigned to each of the three
different types of brackets.
The brackets and wires combination (10 each) will be divided into 9 groups:
Group I: Stainless steel bracket + nickel titanium wire
Group II: Stainless steel bracket + stainless steel wire
Group III: Stainless steel bracket + titanium molybdenum alloy
Group IV: Ceramic bracket + nickel titanium wire
Group V: Ceramic bracket +stainless steel wire
Group VI: Ceramic bracket + titanium molybdenum alloy
Group VII: Self-ligating bracket + nickel titanium wire
Group VIII: Self-ligating bracket + stainless steel wire
Group IX: Self -ligating bracket + titanium molybdenum alloy
The straight length wires to be tested will be engaged into the bracket slot and ligated
passively to the tie wings with stainless steel ligature for all brackets except in the case of
self-ligating brackets.
Each of the 90 bracket-wire samples from every group will be fixed using using super glue
on a custom made steel jig plate of 75 x 10 x 3 mm dimension.
The whole bracket – wire assembly will be positioned vertically in a mechanical testing
machine (Model Lloyd LR50K; Lloyd Instruments Ltd., UK) and then tested for frictional
resistance. A 5N load cell will be calibrated between 0 and 5N and the arch wires will be
drawn through the brackets. The resulting kinetic frictional force will be recorded on a
computer in the form of force-distance graph. Each of the bracket-wire samples will be tested
only once to eliminate the influence of wear. The entire study will be carried out in a dry
state.
Descriptive statistics including mean, standard deviation, minimum and maximum values
will be calculated for each group.
7.3 Does the study require any investigation or interventions to be conducted
on patients or other humans or animals? If so, please describe briefly.
Not applicable
7.4. Has ethical clearance been obtained from your institution?
Not applicable
8.
LIST OF REFERENCES:
1. Loftus BP, Artun J, Nicholls JI, Alonzo TA, Stoner JA. Evaluation of friction during
sliding tooth movement in various bracket-arch wire combinations. Am J Orthod
Dentofacial Orthop 1999;116(3):336-45.
2. Cacciafesta V, Sfondrini MF, Ricciardi A, Scribante A, Klersy C, Auricchio F.
Evaluation of friction of stainless steel and esthetic self-ligating brackets in various
bracket-archwire combinations. Am J Orthod Dentofacial Orthop 2003;124(4):395402.
3. Nishio C, da Motta AF, Elias CN, Mucha JN. In vitro evaluation of frictional forces
between archwire and ceramic brackets. Am J Orthod Dentofacial Orthop 2004;
125(1):56-64.
4. Krishnan M, Kalathil S, Abraham KM. Comparative evaluation of frictional forces in
active and passive self-ligating brackets with various archwire alloys. Am J Orthod
Dentofacial Orthop 2009:136(5):675-82.
5. Doshi UH, Bhad-Patil WA. Static frictional force and surface roughness of various
bracket and wire combinations. Am J Orthod Dentofacial Orthop 2011:139(1):74-9.
9.
SIGNATURE OF THE
CANDIDATE
Dr. DADU MAHAMMEDSAIM SALIMBHAI
10.
REMARKS OF THE GUIDE
This is a genuine study, which will be carried out
by post graduate student under my supervision and
guidance.
11.
NAME AND DESIGNATION OF
(IN BLOCK LETTERS)
11.1 Guide
DR ABRAHAM THOMAS MDS
READER,
DEPARTMENT OF ORTHODONTICS AND
DENTOFACIAL ORTHOPEDICS,
BANGALORE INSTITUTE OF DENTAL
SCIENCES & HOSPITAL, BANGALORE.
11.2 Signature
11.3. Head of the Department
DR VINAYA.S.PAI MDS
PROFESSOR AND HOD,
DEPARTMENT OF ORTHODONTICS AND
DENTOFACIAL ORTHOPEDICS,
BANGALORE INSTITUTE OF DENTAL
SCIENCES & HOSPITAL, BANGALORE.
11.3 Signature
12
12.1 Remarks of Chairman and
Principal
12.2 Signature