Comparison of Alignment Efficiency of Steel Vs Elastomeric Ligatures In Lower Anterior Teeth: A Randomized Clinical Trial
Phase: NA
Conditions: Malocclusion of Anterior Teeth
Sponsor: Khyber College of dentistry

 
Comparison Of Alignment Efficiency Of Steel Vs Elastomeric Ligatures In Lower Anterior 
Teeth: A Randomized Clinical Trial. 
 
Dr. Aatikah Javaid 
BDS 
FCPS II Trainee Orthodontic Department 
KHYBER COLLEGE OF DENTISTRY, PESHAWAR 
Correspondence:  aatikah.javaid1@gmail.com 
Supervisor Prof Dr. Ahsan Mehmood Shah 
BDS, FCPS, M.ORTH, FFDRCSI, MHR, MHPE Chairperson Department of Orthodontics, 
KHYBER COLLEGE OF DENTISTRY, PESHAWAR . 
Approved by CPSP on 9th September,2024 
 
 
 
 

Comparison Of Alignment Efficiency Of Steel Vs Elastomeric Ligatures In 
Lower Anterior Teeth: A Randomized Clinical Trial. 
INTRODUCTION 
It is important to have an efficient treatment approach that yields positive treatment outcomes 
while reducing the time spent in clinical settings and the overall duration of treatment.1 The 
initial stage of fixed appliance therapy involves aligning the teeth, which can vary based on 
different factors. The biological condition of the tissues plays a crucial role in how orthodontic 
forces are applied to the periodontium, enabling tooth movement within the alveolar bone.2 The 
success of orthodontic tooth movement relies on various biological factors such as tooth vitality, 
cellular and connective tissue response, and periodontal health.3 However, the choice of bracket 
system and archwire directly influences these biological factors.4 To effectively address 
crowding in orthodontic treatment, an ideal ligation system should ensure complete bracket 
engagement with the arch wire and demonstrate minimal friction between brackets and the arch 
wire.5 
In orthodontic treatment, achieving proper alignment of anterior teeth is a key objective.6 
Different ligation methods, such as elastomeric and steel ligatures, have been employed to 
achieve alignment.7 Elastomeric ligatures are preferred by orthodontists due to their ease of use 
and reduced chairside time, but the effectiveness is reduced overtime due to absorption and 
friction.8 Steel ligatures on the other hand require manual twisting of wire thereby increasing 
chairside time but provide effective engagement of wire into bracket slot and provide low 
friction mechanics.9 The duration of treatment is an important factor for both patients and 
orthodontists, as it can impact overall treatment efficiency and patient satisfaction.10 In a study 
by Reddy et al on comparison of different ligation method on time to reach alignment reported 
that the mean treatment time for alignment in elastomeric ligature was 176.3±11.08 days while in 
steel ligature was 175.56±9.41days.11 Another study reported the mean treatment time for 
alignment in elastomeric ligature was 224.95±8.702 days while in steel ligature was 
176.15±9.81days.12 
This study aims to compare the mean treatment time required to achieve alignment of anterior 
teeth using elastomeric ligatures versus steel ligatures. By evaluating and analyzing these two 

commonly used ligation techniques, we can gain valuable insights into their respective 
effectiveness in facilitating the alignment of anterior teeth. Owing to the contradictory results of 
the aforementioned studies this study would put to rest the contradictions. Ultimately, the 
findings from this study may contribute to informed decision-making regarding ligation methods, 
optimizing treatment outcomes, and enhancing patient experiences in orthodontic practice. There 
is lack of research on this topic in Pakistan, so this study will provide local statistics. The results 
can be variable across different populations due to genetic, ethnic and environmental factors. 
OBJECTIVE 
To determine the mean treatment time required by elastomeric ligatures and steel ligatures, in 
days, to achieve complete alignment of the lower anterior teeth. 
OPERATIONAL DEFINITIONS 
1. Littles irregularity index: 
Measure of the distance in mm, using a Castroviejo caliper, of the sum of horizontal displacements 
of the anatomical contact points of the mandibular anterior teeth. It will be recorded as 0 (Perfect 
alignment), 1-3 (Minimal irregularity), 4-6 (Moderate irregularity), 7-9 (Severe irregularity), 10 
(Very severe irregularity) 
2. Alignment: 
Littles irregularity index score of zero. Calculated by summing the distances (in mm) of the 
horizontal displacements of the anatomical contact points of the mandibular anterior teeth. 
3. Elastomeric ligature: 
O- shaped synthetic elastic of 0.1" diameter that holds the archwire in bracket slots.  
4.Steel ligature: 
Soft grade stainless steel wire of 0.009” thickness that holds the archwire in bracket slots. 
OUTCOME 
To determine the mean treatment time required by elastomeric ligatures and steel ligatures 
 

RESEARCHER’S HYPOTHESIS   
The treatment time taken to complete alignment of lower anterior teeth is shorter in steel ligature 
ligation than elastomeric ligature. 
 
MATERIALS AND METHODS 
Study Design: Randomized Clinical Trial 
Setting: Department of Orthodontics and Dentofacial Orthopedics, Khyber College of Dentistry 
Peshawar. 
Duration: 6 months after approval of synopsis. 
Sample Size: By using Openepi,13 assuming the mean duration of 224.95+ 8.7 days for 
Elastomeric ligature group and mean duration of 219.95 +9.82 days for steel ligature group 12 , a 
sample of 90 participants per group will detect a 5 days difference in mean duration, with 95% 
power at 5% significance level.  
Sampling Technique:  Consecutive, Non-probability. 
Inclusion criteria 
1. 
Patients coming for fixed orthodontic treatment requiring premolar extraction in 
mandibular arch. 
2. 
Age 12-18 years. 
3. 
No adjunct therapeutic intervention involving functional or orthopaedic appliances. 
4. 
Little’s Irregularity index score of 7-9mm. 
Exclusion criteria 
1. 
Patients with systemic conditions and taking medications affecting tooth movement. 
2. 
Lower anterior teeth that are missing, impacted or unerupted, or have fractured crown, 
restorations, Enamel Defects, Caries. 
3. 
Poor periodontal health  
 

DATA COLLECTION PROCEDURE 
Approval of the hospital ethical committee will be taken. Patients from Orthodontics department, 
Khyber College of Dentistry fulfilling the inclusion criteria will be invited to take part in the 
study. The purpose, procedures, risk and benefits of the study will be explained to them. An 
informed written consent will be taken.  
The subjects fulfilling inclusion criteria will be assigned to one of two groups using lottery 
method. Group A will receive steel ligature, while Group B will receive elastomeric ligature for 
wire engagement in brackets. All participants will be bonded with a metal 0.022" slot of MBT 
pre-adjusted appliances. Archwire sequence will be 0.012 NiTi, 0.014 NiTi, 0.018 NiTi and 
0.019x0.025 NiTi until alignment is reached. Adjustment appointments will be conducted at six-
week intervals. Mandibular dental casts will be taken on the day of appliance placement (T1) and 
then on the day when alignment is reached (T2). Littles irregularity index will be calculated on 
mandibular casts using Castroviejo caliper. The alignment time from the day of appliance 
placement to the day when alignment is reached (T2-T1) for each participant will be recorded in 
days. All the above-mentioned information will be recorded in predesigned proforma (see Annex 
I). 
Bias and confounders will be controlled in the study by strictly following inclusion/exclusion 
criteria, and randomization. Effect modifiers include gender, age and pre-treatment irregularity, 
which will be controlled by randomization. 
Statistical Analysis: 
Data will be analyzed using SPSS (statistical package for social sciences) version 25.0. Mean 
and standard deviation will be calculated for numerical explanatory variables like age and time to 
reach alignment. Frequency and percentage will be calculated for qualitative explanatory 
variables like gender. Independent Samples t Test will be applied to compare time of alignment 
in days between two groups (steel and elastomeric) at T2. Normality of data will be checked 
through Shapiro-Wilk Test. In case of skewed data Mann-Whitney U test will be applied instead 
of independent samples t test. Confounders like age and gender will be controlled through 
stratification. Post- stratification Independent Samples t Test/ Mann-Whitney U test will be 
applied. P value less than or equal to 0.05 will be considered significant. 

 
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ANNEXURE I: DATA COLLECTION PROFORMA 
Comparison of mean treatment time to alignment of anterior teeth of 
elastomeric ligatures versus steel ligatures- A randomized clinical trial  
 Age: ______years 
 
Gender:           ◙ Male             ◙ Female        
Date: ____/______/_________  
 
Case #:_______________  
 
Group     ◙ Steel ligature  (Group A)                 ◙  Elastomeric ligature  (Group B) 
 
1. Littles irregularity index before treatment: ______________mm 
2. Lower brackets bond up (T1), Dated:     /    /   . 
3. Alignment reached (T2), Dated:      /     /     . 
4. Time to reach alignment in mandible (T2-T1) : _______________days