Systematic Review

By Dr. Denise Giovannoni , Dr. Elisa Pacella , Dr. Martina Dari , Dr. Ludovica Caterini , Dr. Martina Mezio
Corresponding Author Dr. Denise Giovannoni
Department of Oral and Maxillo Facial Sciences, Sapienza, Orthognathodontics Unit - Rome - Italy, - Italy
Submitting Author Dr. Elisa Pacella
Other Authors Dr. Elisa Pacella
Department of Oral and Maxillo Facial Sciences, Sapienza, Orthognathodontics Unit - Italy, - Italy

Dr. Martina Dari
Department of Oral and Maxillo Facial Sciences, Sapienza, Orthognathodontics Unit - Italy, - Italy

Dr. Ludovica Caterini
Department of Oral and Maxillo Facial Sciences, Sapienza, Orthognathodontics Unit - Italy, - Italy

Dr. Martina Mezio
Department of Oral and Maxillo Facial Sciences, Sapienza, Orthognathodontics Unit - Italy, - Italy


damon, low-friction, self-ligating, fixed appliances, orthodonthics


This is an open-access article distributed under the terms of the Creative Commons Attribution License(CC-BY), which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Submitted on: 24 Oct 2017 10:25:22 AM GMT
Published on: 08 Nov 2017 05:50:46 AM GMT


Objective: evaluation of friction forces between Damon bracket and conventional bracket considering in
vitro studies of literature.
Materials and methods: evaluation of thirteen in vitro studies of literature from 1998 to 2016.
Results: the production of low friction by self- ligating bracket depends to diameter of archwire and so is
obtained easily with round archwire and another factor that influences the friction is the bracket design.


Sliding a tooth along an archwire is a very common orthodontic procedure to translate tooth, but one of
the disadvantages of this system is the frictional forces between wire and brackets. These forces can result
in decreased treatment efficiency, loss of anchorage and , consequently, unwanted tooth movement. Two
major types of friction can be defined: static friction which is the resistance that prevents initial movements
tooth and kinetic friction which is the force required to resist the sliding motion of one solid object over
another at constant speed (1).
The nature of friction in orthodontics is multifactorial, which is derived from both mechanical and biological
factors; mechanical factors such as archwire properties , method of ligation and bracket properties;
biological factors such a as saliva, plaque, corrosion and food particles (2).
The method of ligation have a central role in the making of friction forces , therefore various method have
been proposed to reduce these forces such as self-ligating bracket. SLBs are ligatureless bracket systems
that have a mechanical device which is built into the bracket to close off the slot. There are two types of
self-ligating bracket: active SLB, that have a spring clip that presses against the archwire and passive SL in
which the self-ligating clip does not press against the wire. The Damon 3 SLB is a passive self- ligating
bracket and use covers that slide vertically in an occlusal direction. The slot size of this brackets is
0.022x0.027 inch.(1).
Nowadays, self-ligating brackets have become very popular in orthodontics practice and both patients and
orthodontist are more interested in using them.
The aim of this review is the evaluation of the studies that compare the friction forces in Damon 3 brackets
and conventional bracket system.


It was realized a search on Pubmed of in vitro studies from 1998 to 2016 using key word like "Damon
bracket", "self-ligating bracket" and "low friction in orthodontic". Have been selected thirteen articles
which are compared self-ligating bracket and conventional bracket.


By the result of the studies analyzed, in literature there are two groups of studies based on the resistance
forces to sliding and static friction in Damon and conventional brackets. One group reported no significant
differences between self-ligating and conventional brackets (1-8- 9-11- 12-13), while the other group (2-3 -

7-10- 14-15- 16-) claimed that self -ligating brackets produce less friction than conventional ones with a
significant difference. These differences depends on the type of wire used; Pandis et al. (8 )mentioned
there was no difference in frictional forces between SLB and conventional brackets because they used
rectangular archwire that fill the slot of Damon bracket and produce more friction; Kumar et al.(6) have
shown that friction appears to increase as archwire diameter increases, also with Damon bracket, in fact
with all the bracket type the 0.019x0.025 inch. steel stainless wire produces the highest friction, even if
Damon 3 passive SL system showed the lowest friction for all dimension of test wire compared to the other
type of bracket tested. The group of studies that claimed the less friction of self- ligating brackets are based
on the use of a round archwire that can’t contact all the surface of the slot and consequently less friction
arise. Tecco et al.(7) have shown that Damon 3 produced less friction with a round wire and that time 3,
SLB active produced more friction; these differences observed among the SLB could be explained by the
differences in the shapes of their little caps that can or not press the wire against the slot and increase the
friction. So two important factors affect the arise of friction forces: diameter of wire, bracket design (5).
The presence of a flared slot allows better guidance of the wire at the bracket corner, like says Crincoli et al.
(3), this slot design reduce the binding and notching of the wire against the corner of the bracket. When
the corner of contact between bracket and archwire is wide, the sliding movement of teeth can be
disturbed by vertical forces produced at both ends of the bracket slot as the bracket archwire angulation
increases and causes binding. Under high magnification of an electron microscope the corners of Damon
brackets slot showed smooth surfaces and so that reduce the friction (4).


Reduction of frictional forces during sliding mechanics increases the efficiency of the orthodontic
treatment, but the choice of bracket system may consider the phase of treatment. SLB system is more
efficient in the alignment phase (6) because produced low friction compared to conventional bracket,
where the ligature contact the wire and make high friction.


1. Mohammad Karim Soltani, Farzaneh Golfeshan Yoones Alizadeh, Jabraiel Mehrzad. Resistance To
Sliding In Clear And Metallic Damon 3 And Conventional Edgewise Brackets: An In Vitro Study. J
Dent Shiraz Univ Med Sci., 2015 March; 16(1 Suppl): 15-20
2. Sujeet Kumar, Shamsher Singh, Rani Hamsa.P.R , Sameer Ahmed, Prasanthma, Apoorva Bhatnagar,
Manreet Sidhu, Pramod Shetty. Evaluation of friction in orthodontics using various brackets and
archwire combinations-an in vitro study. Journal of Clinical and Diagnostic Research. 2014, May,
Vol 8(5): ZC33-ZC36.
3. Vito Crincoli, Letizia Perillo, Maria Beatrice Di Bisceglie, Antonio Balsamo, Vitaliano Serpico,
Francesco Chiatante, Carmine Pappalettere E Antonio Boccaccio. Friction Forces During Sliding Of
Various Brackets For Malaligned Teeth: An In A Vitro Study. The Scientific World Journal Volume
2013, Article ID 871423.
4. Souk Min Lee, Chun-Ju Hwang. A comparative study of frictional force in self-ligating brackets
according to the bracket-archwire angulation, bracket material, and wire type. Korean J Orthod
5. Riccardo Nucera, Antonino Lo Giudice, Giovanni Matarese, Alessandro Artemisia, Ennio Bramanti,
Paolo Crupi, Giancarlo Cordasco. Analtsis of the caracteristics of slot design affecting resistance to
sliding during active archwire configurations. Progress in Orthodontics 2013, 14:35.

6. Vijaya Bhaskara Reddy, Talapaneni Ashok Kumar, Mandava Prasad, Sivakumar Nuvvula, Rajedra
Goud Patil, Praveen Kumar Reddy. A Comparative In-Vivo Evaluation Of The Alignment Efficiency
Of 5 Ligation Methods: A Prospective Randomized Clinical Trial. European Journal of Dentistry, vol
8/issue 1/ Jan-Mar 2014.
7. Simona Tecco, Donato Di Iorio, Riccardo Nucera, Beatrice Di Bisceglie, Giancarlo Cordasco, Felice
Festa. Evaluation of The Friction of Self-Ligating and Conventional Bracket Systems. Eur J Dent
8. Pandis N, Polychronopoulou A, Eliades T. Self-ligating vs conventional brackets in the treatment of
mandibular crowding: a prospective clinical trial of treatment duration and dental effects. Am J
Orthod Dentofacial Orthop 2007; 132: 208-215.
9. Vanessa Vieira Leite, Murilo Baena Lopes, Alcides Gonini Junior, Marcio Rodrigues De Almeida,
Sandra Kisss Moura, Renato Rodrigues De Almeida. Comparison of frictional resistance between
self-ligating and conventional brackets tied with elastomeric and metal ligature in orthodontic
archwires. Dental Press J Orthod.2014 May-June; 19(3):114-9.
10. Maria Regina Guerra Monteiro, Licinio Esmeraldo Da Silva, Carlos Nelson Elias, Oswaldo De
Vasconcellos Vilella. Frictional resistance of self-ligating versus conventional brackets in different
bracket-archwire- angle combinations. J Appl Oral Sci. 2014; 22(3):228-34.
11. 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: 675-682.
12. Scott P, DiBiase AT, Sherriff M, Cobourne MT. Alignment efficiency of Damon3 self-ligating and
conventional orthodontic bracket systems: a randomized clinical trial. Am J Orthod Dentofacial
Orthop 2008; 134: 470.
13. Ehsani S, Mandich MA, El-Bialy TH, Flores-Mir C. Frictional resistance in self-ligating orthodontic
brackets and conventionally ligated brackets. A systematic review. Angle Orthod 2009; 79: 592-601.
14. Pizzoni L, Ravnholt G, Melsen B. Frictional forces related to self-ligating brackets. Eur J Orthod 1998;
20: 283-291.
15. Thomas S, Sherriff M, Birnie D. A comparative in vitro study of the frictional characteristics of two
types of self-ligating brackets and two types of pre-adjusted edgewise brackets tied with
elastomeric ligatures. Eur J Orthod 1998; 20: 589-596.
16. Henao SP, Kusy RP. Evaluation of the frictional resistance of conventional and self-ligating bracket
designs using standardized archwires and dental typodonts. Angle Orthod 2004; 74: 202-211.

Source(s) of Funding

No funding has been taken.

Competing Interests


0 reviews posted so far

0 comments posted so far

Please use this functionality to flag objectionable, inappropriate, inaccurate, and offensive content to WebmedCentral Team and the authors.


Author Comments
0 comments posted so far


What is article Popularity?

Article popularity is calculated by considering the scores: age of the article
Popularity = (P - 1) / (T + 2)^1.5
P : points is the sum of individual scores, which includes article Views, Downloads, Reviews, Comments and their weightage

Scores   Weightage
Views Points X 1
Download Points X 2
Comment Points X 5
Review Points X 10
Points= sum(Views Points + Download Points + Comment Points + Review Points)
T : time since submission in hours.
P is subtracted by 1 to negate submitter's vote.
Age factor is (time since submission in hours plus two) to the power of 1.5.factor.

How Article Quality Works?

For each article Authors/Readers, Reviewers and WMC Editors can review/rate the articles. These ratings are used to determine Feedback Scores.

In most cases, article receive ratings in the range of 0 to 10. We calculate average of all the ratings and consider it as article quality.

Quality=Average(Authors/Readers Ratings + Reviewers Ratings + WMC Editor Ratings)