Download Time efficiency of self-ligating vs conventional

1 Time efficiency of SL vs conventional brackets
Time efficiency of self-ligating vs conventional
brackets in orthodontics: effect of appliances
and ligating systems
Paduano Sergio*, Cioffi Icopo**, Iodice Giorgio**, Rapuano Alessia**, Silva Roberta*
*School of Dentistry, University of Catanzaro Magna Graecia, Catanzaro, Italy
**Department of Oral Sciences, Section of Orthodontics, University of Naples “Federico II”, Italy
Correspondence to:
Via Pansini 5, 80131, Napoli
[email protected]
Ph. +39 081.746.2192
Objectives. The aim of the present study was to compare the speed of archwire change between selfligating (SL) brackets and conventional brackets with elastic and stainless steel (SS) ligatures.
Material and methods. Fifty orthodontic patients, divided into five groups according to the type of fixed appliance and ligating system used (10 subjects=Time 2 SL brackets; 10 subjects = SmartClip SL
brackets; 10 subjects = In-Ovation SL brackets; 10 subjects = conventional brackets with SS ligatures,
10 subjects = conventional brackets with elastic ligatures) were included in the study. The clinical phases were carried out by a unique operator experienced in both conventional and SL brackets techniques.
Aligning and levelling were completed for each subject. The time needed to remove and ligate .019 x
.025 SS archwires in both dental arches was measured for the 5 groups of patients. Independent sample t-test and ANOVA analyses were used.
Results. SL brackets had a significantly shorter mean archwire ligation and removal times when compared with conventional brackets with elastic and SS ligatures. The ligation time in the lower arch was
affected by the type of SL appliance used. Systems with elastic ligatures had a shorter mean archwire
ligation time than systems with SS ligatures. No differences were found between maxillary and mandibular arches in wire ligation and removal times.
Conclusions. The type of bracket has influence on chairside time. SL systems showed a quicker and more efficient wire removal and placement for late orthodontic treatment phases.
Paduano S, Cioffi I, Iodice G, Rapuano A, Silva R. Time efficiency of self-ligating vs conventional brackets in orthodontics: effect of appliances and ligating
systems. Prog Orthod 2008;9(2):30-36.
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PROGRESS in ORTHODONTICS 2008; 9(2):30-36
Time efficiency of SL vs conventional brackets 2
Introduction
Currently self-ligating (SL) brackets
are widely used as they present
with several clinical advantages,
such as low friction1, secure ligation, improved patient comfort,
and quicker chairside time2-4.
Even though the low friction of SL
techniques is being still discussed,
undoubtedly patient comfort and
shorter chairside time are leading issues of these new orthodontic
systems. However, although widely
promoted by orthodontic brands, these issues have been tested only by
few studies in the recent literature.
Recently Turnbull et al compared a
SL bracket with conventional minibrackets and showed that the SL
bracket had significantly quicker
mean archwire ligation times for
both placing and removing wires
compared to the conventional ligating systems3. However, the relative speed ligation time of different SL bracket systems has not
been assessed yet. Therefore, the
aim of the present study was to assess the archwire ligation and removal times of conventional brackets and to compare them to three
different SL brackets with different
open/close slide mechanisms.
Materials and methods
Subjects
Fifty patients scheduled for fixed orthodontic treatment (28 Males, 22
Females; age range 12-30 years)
were selected for this study. Patients
who agreed to the research protocol,
with full permanent dentition excluding third molars, where included in
the study. Subjects who required extractive treatments were not selected.
Subjects were divided in 5 groups
(each one comprising 10 patients)
Scopo. Scopo del presente lavoro è valutare la velocità di sostituzione degli archi ortodontici in apparecchiature auto leganti (SL) e convenzional con legature metalliche (SS) ed elastiche.
Materiali e metodi. Cinquanta pazienti ortodontici sono stati divisi in cinque gruppi in funzione del
tipo di apparecchiatura utilizzata (10 soggetti = Time 2 SL brackets; 10 soggetti = SmartClip SL brackets; 10 soggetti = In-Ovation SL brackets; 10 soggetti = attacchi convenzionali con legature metalliche;
10 soggetti = attacchi convenzionali con legature elastiche). Le fasi cliniche sono state realizzate da un
unico operatore, con esperienza sia in tecnica convenzionale che self ligating. In ogni soggetto le fasi
di allineamento e livellamento erano state già completate. Il tempo necessario per rimuovere e legare
archi in acciaio .019x.025 in entrambe le arcate dentarie è stato misurato per ciascuno dei cinque gruppi di pazienti. Per l’analisi statistica, sono stati impiegati lo student t-test e l’analisi ANOVA one-way.
Risultati. Il tempo di rimozione e applicazione dell’arco nelle apparecchiature SL era significativamente
inferiore rispetto alle apparecchiature convenzionali, sia con legature elastiche che metalliche. Il tempo
medio necessario per legare un arco utilizzando legature elastiche era inferiore rispetto all’utilizzo di
legature metalliche. Nessuna differenza di tempo significativa è stata riscontrata tra l’arcata mascellare e mandibolare, tanto nella rimozione quanto nell’applicazione dell’arco.
Conclusioni. La tipologia di attacco influenza il tempo necessario alla poltrona. I sistemi SL si sono dimostrati più veloci e più efficienti nella rimozione e nell’applicazione di un arco durante le fasi terminali di un trattamento ortodontico.
Key words: Self-ligating appliances, Chairside time.
PROGRESS in ORTHODONTICS 2008; 9(2):30-36
31
1 Time efficiency of SL vs conventional brackets
according to the type of bracket
used and to the type of ligation
system (SmartClip, 3M, Monrovia,
CA - USA; InOvation, GAC, Bohemia, NY - USA; Time2, American
Orthodontics, Sheboygan, WI,
USA; GAC Ovation bracket with
SS ligatures, GAC Ovation bracket
with elastic ligatures).
Appliances
Full arch appliances with 0.022 x
0.028 brackets with Roth prescription were used. Aligning was completed in all subjects. Then 0.019 x
0.025 SS archwires were applied to
all patients to complete levelling, following a Ni-Ti superelastic archwire
0.018 x 0.025 (Sentalloy, GAC).
The time needed to remove and ligate 0.019 x 0.025 SS archwires
was measured for all 50 patients by
means of a stopwatch. The archwire
was positioned starting from upper
right quadrant in all subjects, from
distal to mesial, in both upper and lower arches. Instruments provided with
each of the SL appliances were used
to engage the archwire and
open/close the slot of the brackets.
A standard Mathieau was used to
position and tie the SS ligatures, as
well as the elastomeric ones. The
operator was working at a normal ra-
te. The time taken to open/close the
slide, as well as to remove or replace both SS and elastic ligatures was
measured by a single operator (S.P.),
with significant experience with both
conventional and SL brackets.
Self-ligating appliances
SMARTCLIP
SmartClip has been produced as a
new addition to preadjusted systems
(Fig. 1). It consist of a rhomboidal
mid size bracket provided with twin
wings, torque in base and two nickel titanium clips. Clips are designed
to engage, retain and disengage
Objectifs. Le but de la présente étude était de comparer la vitesse du changement de fil entre les brackets
auto-légants
(SL) et les brackets conventionnelles avec ligatures élastiques et d'acier inoxydable (SS).
Matériel et méthodes. Cinquante patients orthodontiques, divisés en cinq groupes selon le type d'appareil et de ligature utilisés (10 subjects=Time 2 SL brackets; 10 subjects = SmartClip SL brackets; 10 subjects = In-Ovation SL brackets; 10 subjects = conventional brackets with SS ligatures, 10 subjects = conventional brackets with elastic ligatures) ont été inclus dans l'étude. Les phases cliniques ont été effectuées
par un opérateur unique expérimenté dans des techniques conventionnelles et de brackets. L'alignement et
nivellement ont été réalisés pour chaque sujet. On a mésuré le temps nécessaire pour elever a ss .019 x
.025 archwire de l'arcade dentaire supérieure et inférieure pour les 5 groupes de patients. On a employé le t-test indépendant et les analyses d'ANOVA.
Résultats. Les brackets SL ont eu sensiblement un temps moyen plus court de ligature et d'enlèvement du
fil en comparaison avec les brackets conventionnelles liés avec l'élastique et les ligatures métalliques. Le temps
de ligature dans l'arcade inférieure a été affecté par le type d'appareil de SL utilisé. Les systèmes avec les
ligatures élastiques ont eu un temps moyen de ligature inférieur par rapport aux ligatures métalliques.
Aucune différence a été trouvée entre les arcades maxillaires et mandibulaires pour le temps de ligature et
d'enlèvement de fil.
Conclusions. Le type de brackets influence le temps de travail. Les systèmes de SL ont montré une application et remotion enlèvement plus rapides et plus efficaces de fil pendant des phases orthodontiques en
retard de traitement.
Traduit par Maria Giacinta Paolone
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PROGRESS in ORTHODONTICS 2008; 9(2):30-36
Time efficiency of SL vs conventional brackets 4
Fig. 1 3M SmartClip brackets.
Objetivo. El objetivo del presente estudio fue el de comparar la velocidad de cambio del arco entre
auto ligables (SL) y brackets convencionales con ligadura elástica o metálica (SS).
Materiales y métodos. Se incluyeron en el estudio cincuenta pacientes ortodonticos, que fueron divididos en cinco grupos según el tipo de tratamiento fijo y el tipo ligadura aplicada (10 sujetos = Time
2 SL brackets; 10 sujetos= SmartClip SL brackets , 10 sujetos = In-Ovation SL brackets , 10 sujetos =
con brackets convensionale con ligaduras SS, 10 sujetos = con brakets convencional con ligaduras elásticas). Las fases clínicas las siguió un único operador con experiencia en ambas técnicas. El alineamiento
y el nivelamiento fueron concluidos en todos los sujetos. Fue medido el tiempo necesario en los 5 grupos de pacientes, para remover las ligaduras SS en ambas arcadas dentales que tenían arcos .019 x
.025. Se utilizaron Independientemente de la muestra t-test y el análisis ANOVA.
Resultados. En los brackets SL se encontró un tiempo significativamente más corto para remover los
arcos con respecto a los brackets convencionales con ligaduras elásticas y SS. El tiempo para ligar el
arco inferior se vio afectada por el tipo de aparato utilizado SL. Los sistemas con ligaduras elásticas tuvieron un tiempo significativamente más corto con respecto a las ligaduras SS. No se encontraron diferencias en tiempo, entre los maxilares superiores e inferiores durante la aplicación y la remoción de
las ligaduras.
Conclusiones. El tipo de bracket influencia el tiempo de trabajo en la unidad (sillón). Los brackets SL
durante las diferentes fases del tratamiento ortodóntico, mostraron una más rápida y eficiente durante
la remoción y colocación de alambre.
Traducido por Santiago Isaza Penco
PROGRESS in ORTHODONTICS 2008; 9(2):30-36
33
5 Time efficiency of SL vs conventional brackets
Fig. 2 American Orthodontics Time2 brackets.
Fig. 3 GAC In-Ovation brackets.
the arch wire. SmartClip is considered a passive system because the
arch wire is held in place but it is not
bound to the base of the bracket.
The slot of SmartClip is 0.022 x
0.027 for lower incisor and 0.022
x 0.0275 for the remaining teeth.
34
TIME2
Time2 bracket (Fig. 2) is an evolution
of Time, presented by Heiser in
1998. It is a SS twin bracket, provided with a single elastic clip which
may be opened or closed by using
a specially designed instrument. Ti-
me2 is considered an interactive SL
system, because friction has been
suggested to change between early
and late stages of treatments according to the size of archwire used.
PROGRESS in ORTHODONTICS 2008; 9(2):30-36
Time efficiency of SL vs conventional brackets 6
IN-Ovation
These twin brackets (Fig. 3) are
provided with a single clip designed to engage the archwire. The
clip can be easily opened by using
a finger although an especially designed tool (beaver) is available.
In 2002 smaller brackets for the
anterior teeth became available
(In Ovation R).
Statistical analysis
The comparisons of the removal and
ligation times at the upper and lower
arches for the 5 different bracket/ligation systems were carried out by
means of one-way analysis of variance (ANOVA) with Tukey’s posthoc test. Independent sample t-test
was used to compare both the removal and ligation times between
the upper and lower arches for the 5
different bracket/ligation systems. The
use of parametric tests was allowed
by the presence of both normal distribution (Shapiro-Wilk test) and equa-
lity of variance (Levene’s test) in the
analyzed variables. All statistical computations were carried out with a statistical software package (SPSS 13.0,
SPSS Inc, Chicago, IL, USA).
Results
The mean time for archwire removal
and ligation in the upper and lower
dental arches are shown in Table 1.
The average time needed to remove archwires tied with SS ligatures was significantly higher than
SL brackets and conventional brackets tied with elastic ligatures. No
differences were found between SL
brackets both in the upper and lower arches. No significant difference was found in the time needed to remove wires between conventional brackets tied with elastic
ligatures and SL brackets both in
the upper and lower arches.
The time needed to place the wires
into Time2 appliances in the lower
arch was significantly higher when
compared to the other SL systems. SL
appliances had a significantly shorter ligation time when compared to
elastic and SS ligatures on conventional brackets both in the upper
and lower arches. The time required
to engage the wire by using elastic
ligatures on conventional brackets
was significantly shorter when compared to SS ligatures.
Comparison between the maxillary
arch and the mandibular arch showed no difference in wire ligation
and removal times for any of the 5 different bracket/ligation systems tested.
Discussion
Ergonomics 5 and reduction of
chairside time are clinically relevant in orthodontics.
Certainly, the time needed to remove or place archwires, although
Table 1 Mean times (seconds) for wire removal or ligation per arch. NS: no significant difference; S: means different at P <0 .05.
Mean
Upper archwire removal time
Lower archwire removal time
Upper archwire ligation time
Lower archwire ligation time
PROGRESS in ORTHODONTICS 2008; 9(2):30-36
3M Smart Clip
GAC In Ovation
AO Time
Elastic ligatures
SS ligatures
3M Smart Clip
GAC In Ovation
AO Time
Elastic ligatures
SS ligatures
3M Smart Clip
GAC In Ovation
AO Time
Elastic ligatures
SS ligatures
3M Smart Clip
GAC In Ovation
AO Time
Elastic ligatures
SS ligatures
22.3
22.1
22.8
22.0
53.6
22.6
22.3
21.2
22.4
22.4
22.6
22.3
124.2
183.1
22.4
22.5
30.4
122.9
182.5
Std.
Dev.
2.0
1.6
1.8
1.9
2.8
2.1
1.8
4.3
1.7
54.2
1.7
2.0
1.8
3.5
3.3
1.6
1.8
3.4
3.4
3.7
Smart
In
Clip Ovation
x
ns
ns
x
ns
ns
ns
ns
S
S
x
ns
ns
x
ns
ns
ns
ns
3.3
S
x
ns
ns
x
ns
ns
S
S
S
S
x
ns
ns
x
S
S
S
S
S
S
Time
ns
ns
x
ns
S
ns
ns
x
ns
S
ns
ns
x
S
S
S
S
x
S
S
Elastomeric
SS
ligatures ligatures
ns
S
ns
S
ns
S
x
S
S
x
ns
S
ns
S
ns
S
x
S
S
Sx
S
S
S
S
S
S
x
S
S
X
S
S
S
S
S
S
x
S
S
X
35
7 Time efficiency of SL vs conventional brackets
interesting, is of less significance
when compared to low friction6-7
and other characteristics of SL
brackets, such as secure ligation
and improved patient comfort. However, it has been suggested that
saving chairside time might be a
useful aspect of SL appliances3.
The results of the current study confirm that SL appliances drastically reduce chairside time when compared to the conventional twin brackets, by shortening the average time
needed to place or remove archwires. This result is in agreement
with Turnbull et al and Harradine
who reported a shorter ligation time
for Damon2 SL brackets3-4.
In the current study, removing archwires was on average quicker than
placing them, at least for conventional twin brackets ligated by
means of elastic ligatures or SS ties.
Conversely, no differences in wire
removal time between brackets made of different open/close slot mechanism have been found. On the
other hand, placing the lower archwires in Time2 appliances required
more time than in the other SL brackets. These data suggest that wire
removal time is not affected by differences in the geometr y of
open/close slot mechanisms, while
wire ligation time was influenced by
the type of SL bracket.
It must be noted that the ergonomy
of SL appliances was affected by
the different bracket designs. For
instance, engaging the wire in
SmartClip brackets needed the
teeth to be slightly pushed to reduce patient discomfort while, in
other SL brackets, that do not have
clip mechanism, patient discomfort was perceived to be less.
36
It was noted also that the slide mechanism of Time2 was more difficult to open when compared to
other SL brackets, i.e. opening the
slide needed more carefulness to
avoid bracket debonding.
Furthermore, we found slightly tricky
placing the engaging instrument into the In-ovation brackets.
On average 3 and 2 minutes were necessary to ligate archwires by
means of SS ligatures and elastic
ones, respectively. On the other
hand, less then 30 seconds were
required to engage a wire in SL appliances. These data suggest that
using SL appliances may save more than 30% of chairside time during wire adjustements, i.e. more
than an hour in a working day.
Finally, using SL brackets decreased
reliance on assistant support. This
aspect could be of great interest for
orthodontists who do not have chairside support from dental assistants.
It is important to note that for this
study experience of the operator was
not considered a factor influencing
archwire ligation time. In this respect,
further studies are needed to assess
whether the same results may be reported in groups with different experience, such as postgraduate students or dental students. Moreover, in
this study .019x .025 SS archwires
were used to avoid any sort of influence of crowding or incomplete
aligning on the outcomes, and to reduce the wire effect. In facts, archwire size has been reported to affect
archwire ligation speed3.
Finally, it might be argued that SL brackets are consistently more expensive
than conventional twin brackets. This
cost, however, is certainly covered by
reduction in chairside time3,8-10.
Conclusions
The results of the present study confirme that SL appliances drastically
reduce chairside time.
SL appliances have a quicker
mean archwire ligation and removal time when compared to conventional twin brackets ligated by
means of SS or elastic ties.
The type of open/close clip mechanism might influence archwire ligation speed.
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