UNIVERSIDADE ESTADUAL PAULISTA
“JÚLIO DE MESQUITA FILHO”
Instituto de Ciência e Tecnologia
Campus de São José dos Campos
ORIGINAL ARTICLE DOI: https://doi.org/10.4322/bds.2024.e4369
1
Braz Dent Sci 2024 July/Sept;27 (3): e4369
This is an Open Access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in
any medium, provided the original work is properly cited.
Comparative evaluation of the canal transportation after
retreatment with Solite RS3 and Protaper Universal retreatment
files: a nano computed tomography study
Avaliação comparativa do desvio do canal após retratamento endodôntico com limas de retratamento Solite RS3 e Protaper
Universal: um estudo de nano tomografia computadorizada
Sruthi SAIRAMAN1 , Pradeep SOLETE1 , Ganesh JEEVANANDAN2 , Divya SENA1 , Kavalipurapu Venkata TEJA3 ,
Mohammed MUSTAFA4
1 - Saveetha University, Saveetha Institute of Medical and Technical Sciences, Saveetha Dental College and Hospitals, Department of
Conservative Dentistry and Endodontics. Chennai, India.
2 - Saveetha University, Saveetha Institute of Medical and Technical Sciences, Department of Pediatric and Preventive Dentistry Saveetha
Dental College and Hospitals. Chennai, India.
3 - Mamata Institute of Dental Sciences, Department of Conservative Dentistry and Endodontics. Hyderabad, Telangana, India.
4 - Prince Sattam Bin Abdulaziz University, College of Dentistry, Department of Conservative Dental Sciences. Al-Kharj, Saudi Arabia.
How to cite: Sairaman S, Solete P, Jeevanandan G, Sena D, Teja KV, Mustafa M. Comparative evaluation of the canal transportation
after retreatment with Solite RS3 and Protaper Universal retreatment les: a nano computed tomography study. Braz Dent Sci.
2024;27(3):e4369. https://doi.org/10.4322/bds.2024.e4369
ABSTRACT
Objective: The primary objective of instrumentation during retreatment is to preserve the original curvature of
the canal while removing gutta-percha. The current study assesses the canal transportation after retreatment
with two different retreatment le systems. Materials and Methods: Sixty single-rooted teeth, extracted and
decoronated, were obturated at a standardized root length of 16 mm. The samples were then divided into two
groups, each comprising 20 single-rooted teeth. The instrumentation was performed using Solite RS3 Retreatment
les for one group and ProTaper Retreatment les for the other. After both pre-operative and post-operative
nano-CT scans, 3D reconstruction was conducted for analysis. Sections of the pre-operative and post-operative
samples were taken at 7 mm, 5 mm, and 3 mm and 1 mm from the apex to calculate the canal transportation.
Statistical analysis between the two groups was carried out using an independent t-test. Results: Solite RS3
retreatment les exhibited a statistically signicant difference at all three levels (p < 0.05) when compared
to ProTaper retreatment les, thus showing lesser canal transportation than the latter. Conclusion: Based on
the above results, it can be concluded that Solite RS3 induced minimal canal transportation and resulted in a
relatively centered preparation compared to the ProTaper Retreatment system.
KEYWORDS
Canal transportation; Nano-CT; Remaining dentin thickness; Retreatment; Solite RS3.
RESUMO
Objetivo: O objetivo principal da instrumentação durante o retratamento é preservar a curvatura original do canal
durante a remoção da guta-percha. O presente estudo avalia o desvio do canal após o retratamento endodôntico
com dois sistemas de limas de retratamento diferentes. Material e Métodos: Sessenta dentes uniradiculares,
extraídos e com as coroas removidas, foram obturados em um comprimento de raiz padronizado de 16 mm. As
amostras foram então divididas em dois grupos, cada um com 20 dentes uniradiculares. O preparo biomecânico
foi realizado utilizando limas de retratamento Solite RS3 para um grupo e limas de retratamento ProTaper
para o outro. Após o escaneamento pré e pós-operatórias no nano-CT, a reconstrução 3D foi conduzida para
análise. Secção das amostras pré e pós-operatórias foram retiradas a 7 mm, 5 mm e 3 mm e 1mm do ápice para
2
Braz Dent Sci 2024 July/Sept;27 (3): e4369
Sairaman S et al.
Comparative evaluation of the canal transportation after retreatment with Solite RS3 and Protaper Universal retreatment files: a nano computed tomography study
Sairaman S et al. Comparative evaluation of the canal transportation
after retreatment with Solite RS3 and Protaper Universal
retreatment files: a nano computed tomography study
INTRODUCTION
The prognosis of a root canal treatment
is dependent on the complete elimination or,
at the very least, a substantial reduction in
bacterial load [1]. However, multiple studies have
conrmed the development of apical periodontitis
in 30 to 44.9% of root canal-treated teeth [2,3].
In such cases, the preferred and recommended
line of treatment is non-surgical endodontic
retreatment [4] Over the years, many methods
including manual instrumentation, rotary
systems, ultrasonics, and reciprocation systems
have been used to eliminate the previously
existing lling material [5]. Ongoing research
and advancements in both instrument design
and techniques have resulted in the development
of numerous retreatment le systems. Several
variables, such as surface treatment, active
cutting tip, cross-sectional design, cutting
angle, and taper significantly influence the
effectiveness of these systems and the duration
of gutta-percha removal (GP) [6]. In cases of
non-surgical endodontic retreatment, after
retrieving the previous lling material, the canal
must be enlarged and debrided sufciently to
allow adequate disinfection while maintaining
the canal curvature. [7] Nickel-titanium (NiTi)
instruments have proven to be more effective
in shaping the root canals in comparison to
manual instrumentation [8]. Their use ensures
the preservation of the canal anatomy and
the precise positioning of the apical foramen,
resulting in well-tapered root canal preparations.
During cleaning and shaping procedural errors
such as ledge formation, canal blockage, apical
transportation, and root perforations tend to occur
which decreases the success rate of endodontic
retreatment [9,10]. Excessive dentin removal
results in the tooth being more susceptible to
root fractures, especially if additional forces
are used during the obturation or restoration
stage [11]. When canal preparation is off-
centric, the excessive removal of dentin from
one side causes a change in stress distribution
in the buccolingual plane and increased root
flexure [12]. A vertical root fracture of the
tooth is made more likely by this change in the
distribution of radicular stress from the cervical to
the apical dentin [12]. Transportation, as dened
by the American Association of Endodontists
in The Glossary of Endodontic Terms (2015),
refers to the removal of the canal wall structure
on the outer curve in the lower half of the canal.
This occurs because files have a tendency to
return to their original straight shape during the
preparation of the canal. Apical transportation
will result in difculty in obtaining a stop for
apical gutta-percha, incorrect apical seal, and
even extrusion of irrigants and sealers which
may adversely affect the periodontium [13].
Root canal treatment failure includes inadequate
obturation, inadequate cleaning, shape,
disinfection, instrument separation, presence
of a persistent periapical lesion, and violation
of the apical foramen [14,15]. In recent years,
numerous retreatment systems have become
available, and this study specically evaluates two
retreatment le systems: Solite RS3 Retreatment
le system (Solite Dental, India) and ProTaper
Universal Retreatment (Dentsply Maillefer,
Ballaigues, Switzerland). Each of these systems
comprises three les, with each le specically
designated for the removal of gutta-percha
from the coronal, middle, and apical thirds of
the root canal. The ProTaper Retreatment les
(Dentsply Maillefer, Ballaigues, Switzerland)
have been thoroughly studied in the past for
their effectiveness and safety in both straight
and curved canals [16-21]. The current study
evaluates the effect of different metallurgy-based
retreatment le systems on canal transportation
during gutta percha retrieval utilizing nano-
computed tomography. Nano-CT represents a
technological advancement over conventional
micro-computed tomography, with a signicantly
reduced focal spot size of 400 nm compared to the
calcular o desvio do canal. A análise estatística entre os dois grupos foi realizada através do teste t independente.
Resultados: As limas de retratamento Solite RS3 exibiram uma diferença estatisticamente signicativa em todos
os três níveis (p < 0,05) quando comparadas às limas de retratamento ProTaper, mostrando, portanto, menor
desvio de canal do que estas últimas. Conclusão: Com base nos resultados acima, pode-se concluir que as limas
Solite RS3 induziu o desvio de canal mínimo e resultou em uma preparação relativamente centralizada em
comparação ao sistema de retratamento ProTaper.
PALAVRAS-CHAVE
Desvio de canal; Nano-CT; Espessura de dentina remanescente; Retratamento; Solite RS3.
3
Braz Dent Sci 2024 July/Sept;27 (3): e4369
Sairaman S et al.
Comparative evaluation of the canal transportation after retreatment with Solite RS3 and Protaper Universal retreatment files: a nano computed tomography study
Sairaman S et al. Comparative evaluation of the canal transportation
after retreatment with Solite RS3 and Protaper Universal
retreatment files: a nano computed tomography study
latter’s range of 5–50 μm [22]. This advancement
ensures a more precise scan for assessing dentin
thickness and therefore canal transportation.
The study aims to superimpose the nano-CT scans
obtained before and after the removal of lling
material, analyzing the canal transportation
remaining at 1 mm, 3 mm, 5 mm, and 7 mm from
the apex. The null hypothesis posits that there is
no disparity in canal transportation at different
levels between the two retreatment systems.
MATERIALS AND METHODS
This study was done following the PRILE
guidelines as described in Flowchart 1 [23]
The sample size for the present study was
calculated from a previous study which assessed
canal transportation between two retreatment
file systems using Cone Beam Computerised
Tomography [24]. Based on the assessment a
total sample size of 60 was calculated at a power
of 95% (1 - β = 0.95, α = 0.05).
Sixty single-rooted teeth with straight canals
(curvature of less than 5 degrees) [25] were
chosen for this study. Teeth with pulp stones,
resorptive defects, previous root canal therapy,
cracks, and fractures were excluded from the
study. Radiographic assessments were conducted
on each tooth to identify any deformities, and
those with deformities were excluded. To establish
a consistent working length of 16 mm [26],
the teeth were subjected to decoronation using
diamond discs. The access was subsequently
established using an Endo Access Bur 2 (Dentsply
Maillefer, Ballaigues, Switzerland). A 2.5 mL
solution of 3% sodium hypochlorite (Prime Dental,
India) was used to clean the canal. To verify
that the canal is clear, 10K les (Mani, Japan)
were used until the end of the le could be seen
at the tip of the tooth apex, and the working
length was estimated to be 0.5 mm less than
this measurement. For the chemomechanical
preparation, ProFit S3 (ProFit Dental, India)
[27,28] was employed up to PF3, with irrigation
using 2.5 mL of 3% sodium hypochlorite between
each le. After drying the canals with paper points,
root canal lling was performed using PF3 gutta-
percha(GP) cones (ProFit Dental, India) and AH
Plus sealer (Dentsply DeTrayGmBH, Konstanz,
Germany) employing the single cone matched
taper technique. Excess gutta-percha at the canal
orice level was removed using a heated plugger.
The adequacy of the lling was assessed through
periapical radiographs, ensuring homogeneity and
the absence of voids. Insufcient root canal llings
were replaced after removal. Orices were sealed
with a composite restoration (Neospectra ST,
Dentsply Sirona, USA). The specimens were stored
for two weeks in a 1.5-mL graduated Eppendorf
microcentrifuge tube that was lled with distilled
water. The storage temperature was consistently
maintained at 37°C, while the humidity level was
consistently maintained at 100%. This storage
condition was necessary to guarantee that the
sealer completely solidied. A solitary operator
conducted all endodontic treatments.
Nano- CT scanning
The Bruker SKYSCAN2214 scanner from Bruker
Micro-CT in Kontich, Belgium, known for its high
precision, was employed for scanning the prepared
specimens. Scan parameters comprised 100 kV
(10W and 100A), 1100 ms exposure, and a at
panel detector with 360° rotation and 0.3° rotation
step. The NRecon software from Bruker-microCT
in Kontich, Belgium, utilizing a modied Feldkamp
cone-beam reconstruction algorithm, was utilized
for image reconstruction. The original grayscale
images underwent ne-tuning functions, such as a
Gaussian lter (smoothing, kernel = 2), 40% beam
hardening correction, 0.50 post-alignment, and
ring artifact correction of 10 to address potential
acquisition misalignment. The image was then
scaled to a xed row and column size of 1944 x
3072, with a pixel size of 11999.58 nm.
Retreatment procedure
Sixty samples (N=60) were randomly
allocated into each of the two categories of
specimens. Group 1 underwent retreatment
using the Solite RS3 (n=30) retreatment file
system (Solite Dental, India), while Group
2 received retreatment with the ProTaper Universal
retreatment file systems (n=30) (Dentsply
Maillefer, Ballaigues, Switzerland). Both systems
included les for the coronal, middle, and apical
thirds of the root canal system GP retrieval.
Specications of the retreatment les
● Solite RS3: RS1 (30/.08, 15 mm), RS2
(25/.07, 18 mm), RS3 (20/.06, 23 mm)
● ProTaper Retreatment File System: D1
(30/.09, 16 mm), D2 (25/.08, 18 mm), D3
(20/.07, 22 mm)
4
Braz Dent Sci 2024 July/Sept;27 (3): e4369
Sairaman S et al.
Comparative evaluation of the canal transportation after retreatment with Solite RS3 and Protaper Universal retreatment files: a nano computed tomography study
Sairaman S et al. Comparative evaluation of the canal transportation
after retreatment with Solite RS3 and Protaper Universal
retreatment files: a nano computed tomography study
Flowchart 1 - Methodology flowchart according to PRILE guidelines.
Manufacturer instructions were followed,
and no solvent was used during the procedure.
Irrigation was performed using 3% sodium
hypochlorite- 2.5mL. After the nal le use, the
canals were irrigated again with 3% sodium
hypochlorite 10 mL, followed by regular saline
10 mL, and dried with paper points. Files were
discarded after four uses or when noticeable
changes were observed in the utes.
Retreatment was considered complete
when les reached the working length, dentinal
walls were smooth, and no lling material was
visible under an optical microscope. A second
scan of each sample was conducted using the
SKYSCAN2214 scanner with the same settings.
Nano-CT imaging analysis and measurements
Sections of the tooth at 1 mm, 3 mm, 5 mm,
and 7 mm levels from the apex were made to
both preoperative and postoperative scans as
described by Gambill et al. [29] To assess the
apical transportation, the distance from the
margin of the lled samples to the external root
border was calculated. The same measurements
were then repeated after GP retrieval.
Canal transportation is measured as (m1 -
m2) - (d1 - d2), where m1, d1 are the shortest
distances from the mesial and distal edges of
the root, respectively, to the related edges of
the lled canal, and m2, d2 are the shortest
5
Braz Dent Sci 2024 July/Sept;27 (3): e4369
Sairaman S et al.
Comparative evaluation of the canal transportation after retreatment with Solite RS3 and Protaper Universal retreatment files: a nano computed tomography study
Sairaman S et al. Comparative evaluation of the canal transportation
after retreatment with Solite RS3 and Protaper Universal
retreatment files: a nano computed tomography study
distances from the mesial and distal edges of
the root, respectively, to the related edges of the
canal after GP retrieval by Gambill et al. [29] Pre
and post-measurements of canal transportation
for Solite RS3 is represented in Figure 1 and
for ProTaper Retreatment is represented in
Figure 2 using Nano CT respectively.
Statistical analysis
SPSS software (IBM Corp, SPSS Inc, Chicago,
IL, USA) version 23 was used for statistical data
analysis. Normality was assessed using the
Shapiro-Wilk test, and as the results were found
to be parametric, the independent t-test was
applied at a 95% condence interval.
RESULTS
The mean canal transportation and standard
deviation values (μm) at the 3 levels for both
the le systems respectively are represented in
Table I. The results show that Solite RS3 showed
lesser deviation from original canal morphology
than ProTaper retreatment at the 4 levels - 1 mm,
3 mm, 5 mm, and 7 mm from the apex (p<0.05).
DISCUSSION
Ensuring a smooth and tapered
preparation from the canal orice to the apex
while simultaneously preserving the canal
morphology presents a challenge in the context
of endodontic retreatment, as the canal has
already undergone instrumentation by the
previous operator [30]. Endodontic literature
has consistently re-established that canal
instrumentation often results in the straightening
of the canal, leading to a modication of the initial
canal anatomy [31]. Typically, this straightening
manifests on the outer canal wall, resulting in a
preparation that exhibits slight deviation towards
one side [32]. The current study evaluates canal
transportation in standardized samples with
relatively straight canals during retreatment to
discern the degree to which the retreatment
system inuences such deviations, considering
that the shaping of canals is considerably less
operator-dependent due to the canals being
relatively straight. The canal transportation is
calculated at different specied levels: 1 mm,
3 mm, 5 mm, and 7mm from the apex, adhering to
the standard methodology adopted in computed
tomography analysis [29].
Figure 1 - Represents the measurement of the shortest distance
between the canal and edge of the root pre and pos retreatment
using Solite RS3 system.
Figure 2 - Represents the measurement of the shortest distance
between the canal and edge of the root pre and pos retreatment
using ProTaper Universal retreatment system.
6
Braz Dent Sci 2024 July/Sept;27 (3): e4369
Sairaman S et al.
Comparative evaluation of the canal transportation after retreatment with Solite RS3 and Protaper Universal retreatment files: a nano computed tomography study
Sairaman S et al. Comparative evaluation of the canal transportation
after retreatment with Solite RS3 and Protaper Universal
retreatment files: a nano computed tomography study
Nano-CT employs a high-power nanofocus
X-ray source for accurately characterizing and
quantifying tissue microarchitectures [33].
While micro-CT has long been regarded as the
gold standard for analyzing shaping ability
and obturation quality, recent studies highlight
the nuanced capabilities of nano-CT, capable
of detecting changes that micro-CT may not
precisely determine, which is why the present
study has chosen this modality for analysis [34].
The introduction of NiTi alloys revolutionized
endodontic treatment, signicantly enhancing the
quality of root canal procedures [35]. Despite their
numerous advantages, such as super elasticity
and preservation of original canal morphology,
NiTi alloys exhibit an undesirable shape memory
effect [36,37]. This effect, likely responsible for
root canal transportation, can lead to a loss in
centering ratio and alteration of the original
canal anatomy. Consequently, certain areas
of the canal may remain untouched, resulting
in dentin loss and inefficient cleaning [38].
To address these challenges, thermal treatment of
NiTi alloys was introduced to enhance exibility,
increase cyclic and torsional fatigue resistance,
and eliminate the undesirable shape memory
effect [39,40] [41]. This thermal treatment
renders the instruments more deformable with
pseudo-elasticity, introducing a controlled
memory effect [41]. Instruments subjected to
thermomechanical treatment reduce root canal
transportation by avoiding the straightening of
curved root canals during preparation [42].
The observed statistical disparity in apical
transportation between the Solite RS3 and
ProTaper Universal retreatment systems can be
attributed to its thermomechanical treatment.
The Solite RS3 le, being heat-treated, exhibits
better exibility, and its taper is less than that
of ProTaper, leading to dentine preservation
and preventing canal transportation. The D3 le
in the ProTaper Universal retreatment system
has a 7% taper at the tip, causing the le to be
stiff and leading to an off-centered preparation
in comparison to Solite RS3 while aside from
its thermomechanical treatment, has a taper
of 6% at the tip [43]. This discrepancy results
in the observed difference in dentin loss and
transportation at the apical level. The lower canal
centering ability also implies reduced remaining
dentin thickness on one side of the root, as
established by the literature, which indicates
that retreatment induces more dentinal defects
compared to primary endodontic treatment [44].
In addition to achieving clinical success
outcomes by reducing bacterial load and attaining
a sound coronal and apical seal, clinicians should
consider the long-term durability of the treated
tooth to prevent catastrophic failures, such as
vertical root fractures. Endodontically treated
teeth are predisposed to a higher susceptibility
to fractures, primarily attributed to alterations
in canal curvature, cross-section, and the loss
of circumferential dentin, thereby inuencing
stress distribution across the root dentin [45-47].
The choice of retreatment system plays a crucial
role in determining the extent of dentinal
loss, and higher taper systems, like ProTaper,
may contribute to increased root flexure and
susceptibility to vertical root fractures [48]. Even
the choice of glide path and operator experience
clinically alters the pain [49,50].
The ProTaper Retreatment system remains
widely tested and used as it was the rst retreat-
ment le system to be introduced, prompting the
present study to compare its efcacy with the
Table I - Represents the Mean and standard deviation values (μm) of the canal transportation for both the groups at 1 mm, 3 mm,5 mm, and 7
mm respectively. At all levels, Solite RS3 showed a statistically significant difference compared to ProTaper retreatment files (p<0.05)
Groups Mean ± Std. Deviation (μm) p value
At 7 mm from apex Solite RS3 0.0220 ± 0.0154 p = 0.011*
ProTaper Retreatment 0.0410 ± 0.0347
At 5 mm from Apex Solite RS3 0.0280 ± 0.0139 p = 0.029*
ProTaper Retreatment 0.0340 ± 0.0217
At 3 mm from Apex Solite RS3 0.0270 ± 0.0116 p = 0.012*
ProTaper Retreatment 0.0320 ± 0.0204
At 1 mm from Apex Solite RS3 0.0260 ± 0.0084 p = 0 .002*
ProTaper Retreatment 0.0300 ± 0.0182
*Indicates statistically significant difference (p<0.05).
7
Braz Dent Sci 2024 July/Sept;27 (3): e4369
Sairaman S et al.
Comparative evaluation of the canal transportation after retreatment with Solite RS3 and Protaper Universal retreatment files: a nano computed tomography study
Sairaman S et al. Comparative evaluation of the canal transportation
after retreatment with Solite RS3 and Protaper Universal
retreatment files: a nano computed tomography study
relatively new Solite RS3 system. Although the
current study assesses apical transportation in
relatively straight canals, other parameters such
as remaining lling material, remaining dentin
thickness after retreatment, and crack propaga-
tion need evaluation to determine the optimal
le system for retreatment, posing a limitation
to the study.
It is essential to acknowledge that, compared
to micro-CT, nano-CT imaging signicantly taxes
computer processing. The study’s inability to use
the nanofocus mode due to physical limitations
in root size adds to this consideration. Further
research incorporating multiple retreatment
le systems and curved canals is recommended
to validate and extend these findings. Based
on the findings presented, it is reasonable to
conclude that Solite RS3 induces minimal canal
transportation and yields a more centrally
positioned preparation compared to the ProTaper
Retreatment system. The observed attributes of
Solite RS3, including its heat treatment and lower
taper, position it as a promising retreatment le
system. These features contribute to effective
gutta-percha removal while concurrently
preserving dentin integrity.
CONCLUSION
Based on the findings presented, it is
reasonable to conclude that Solite RS3 induces
minimal canal transportation and yields a more
centrally positioned preparation compared to
the ProTaper Retreatment system. The observed
attributes of Solite RS3, including its heat
treatment and lower taper, position it as a
promising retreatment le system. These features
contribute to effective gutta-percha removal
while concurrently preserving dentin integrity.
Acknowledgements
The authors would like to acknowledge The
White Lab, Saveetha Dental College for their help
in carrying out the nano-computed tomography
study.
Author’s Contributions
SS, PS, GJ, DS, KVT, MM: Methodology,
Writing – Review & Editing. SS, DS, KVT, MM: Data
Curation Writing – Original Draft Preparation. SBD:
Funding Acquisition. PS, GJ: Conceptualization,
Software, Validation, Formal Analysis, Visualization,
Supervision, Project Administration.
Conict of Interest
The authors have no conicts of interest to
declare.
Funding
This research did not receive any specic
grant from funding agencies in the public,
commercial, or not-for-prot sectors.
Regulatory Statement
This study protocol was reviewed and
approved by the SRB committee at Saveetha
Dental College, Saveetha Institute of Medical
and Technical Sciences,Chennai, India approval
number SRB/SDC/ENDO-2105/22/051.
REFERENCES
1. Tandon J, Taneja S, Bhalla VK, Jain A. Evaluation of bacterial
reduction at various stages of endodontic retreatment after use
of different disinfection regimens: an in vivo study. Eur Endod
J. 2022;7(3):210-6. http://doi.org/10.14744/eej.2022.42713
PMid:36217643.
2. Kielbassa AM, Frank W, Madaus T. Radiologic assessment
of quality of root canal fillings and periapical status in
an Austrian subpopulation: an observational study. PLoS
One. 2017;12(5):e0176724. http://doi.org/10.1371/journal.
pone.0176724 PMid:28464019.
3. Boucher Y, Matossian L, Rilliard F, Machtou P. Radiographic
evaluation of the prevalence and technical quality of root
canal treatment in a French subpopulation. Int Endod
J. 2002;35(3):229-38. http://doi.org/10.1046/j.1365-
2591.2002.00469.x PMid:11985674.
4. Torabinejad M, Corr R, Handysides R, Shabahang S. Outcomes of
nonsurgical retreatment and endodontic surgery: a systematic
review. J Endod. 2009;35(7):930-7. http://doi.org/10.1016/j.
joen.2009.04.023 PMid:19567310.
5. Gomes NN, de Carvalho GM, Júnior ECS, Garcia LDFR, Marques
AAF, de Carvalho FMA. Filling material removal with reciprocating
and rotary systems associated with passive ultrasonic irrigation.
Eur Endod J. 2017;2(1):1-7. http://doi.org/10.5152/eej.2017.16037
PMid:33403335.
6. Rödig T, Hausdörfer T, Konietschke F, Dullin C, Hahn W, Hülsmann
M. Efficacy of D-RaCe and ProTaper Universal Retreatment
NiTi instruments and hand files in removing gutta-percha from
curved root canals - a micro-computed tomography study.
Int Endod J. 2012;45(6):580-9. http://doi.org/10.1111/j.1365-
2591.2012.02014.x PMid:22264204.
7. Conceição Limongi PBO, Amaral AP, Pelegrine RA, da Silveira
Bueno CE, Kato AS, de Martin AS,etal. Removal of obturation
material from root canals using a combination of reciprocal
instrumentation and different final irrigation techniques. Iran
Endod J. 2020;15(3):147-54. PMid:36703806.
8
Braz Dent Sci 2024 July/Sept;27 (3): e4369
Sairaman S et al.
Comparative evaluation of the canal transportation after retreatment with Solite RS3 and Protaper Universal retreatment files: a nano computed tomography study
Sairaman S et al. Comparative evaluation of the canal transportation
after retreatment with Solite RS3 and Protaper Universal
retreatment files: a nano computed tomography study
8. Walia HM, Brantley WA, Gerstein H. An initial investigation of
the bending and torsional properties of Nitinol root canal files.
J Endod. 1988;14(7):346-51. http://doi.org/10.1016/S0099-
2399(88)80196-1 PMid:3251996.
9. Alrahabi M, Zafar MS, Adanir N. Aspects of clinical malpractice
in endodontics. Eur J Dent. 2019;13(3):450-8. http://doi.
org/10.1055/s-0039-1700767 PMid:31795008.
10. Mantri SP, Kapur R, Gupta NA, Kapur CA. Type III apical
transportation of root canal. Contemp Clin Dent. 2012;3(1):134-6.
http://doi.org/10.4103/0976-237X.94565 PMid:22557916.
11. Patel S, Bhuva B, Bose R. Present status and future directions:
vertical root fractures in root filled teeth. Int Endod J.
2022;55(Suppl 3):804-26. http://doi.org/10.1111/iej.13737
PMid:35338655.
12. Ossareh A, Rosentritt M, Kishen A. Biomechanical studies on the
effect of iatrogenic dentin removal on vertical root fractures. J
Conserv Dent. 2018;21(3):290-6. http://doi.org/10.4103/JCD.
JCD_126_18 PMid:29899632.
13. Wu MK, Fan B, Wesselink PR. Leakage along apical root fillings
in curved root canals. Part I: effects of apical transportation
on seal of root fillings. J Endod. 2000;26(4):210-6. http://doi.
org/10.1097/00004770-200004000-00003 PMid:11199720.
14. Siqueira JF Jr. Aetiology of root canal treatment failure: why
well-treated teeth can fail. Int Endod J. 2001;34(1):1-10. http://
doi.org/10.1046/j.1365-2591.2001.00396.x PMid:11307374.
15. Tabassum S, Khan FR. Failure of endodontic treatment: the
usual suspects. Eur J Dent. 2016;10(1):144-7. http://doi.
org/10.4103/1305-7456.175682 PMid:27011754.
16. Giuliani V, Cocchetti R, Pagavino G. Efficacy of ProTaper
universal retreatment files in removing filling materials during
root canal retreatment. J Endod. 2008;34(11):1381-4. http://doi.
org/10.1016/j.joen.2008.08.002 PMid:18928852.
17. Gu L-S, Ling J-Q, Wei X, Huang X-Y. Efficacy of ProTaper
Universal rotary retreatment system for gutta-percha removal
from root canals. Int Endod J. 2008;41(4):288-95. http://doi.
org/10.1111/j.1365-2591.2007.01350.x PMid:18081804.
18. Fariniuk LF, Azevedo MAD, Carneiro E, Westphalen VPD, Piasecki
L, da Silva Neto UX. Efficacy of protaper instruments during
endodontic retreatment. Indian J Dent Res. 2017;28(4):400-5.
http://doi.org/10.4103/ijdr.IJDR_89_16 PMid:28836531.
19. Ciftcioglu E, Sungur Guzel R, Akbal Dincer G, Karakaya G, Kucukay
ES. Efficiency of ProTaper Universal Retreatment, Reciproc Blue
and XP-endo Shaper in the removal of a bioceramic-based root
canal filling. Eur Oral Res. 2023;57(3):159-64. PMid:37929225.
20. Ma J, Al-Ashaw AJ, Shen Y, Gao Y, Yang Y, Zhang C, etal.
Efficacy of ProTaper Universal Rotary Retreatment system for
gutta-percha removal from oval root canals: a micro-computed
tomography study. J Endod. 2012;38(11):1516-20. http://doi.
org/10.1016/j.joen.2012.08.001 PMid:23063227.
21. Ozyurek T, Ozsezer-Demiryurek E. Efficacy of protaper next
and protaper universal retreatment systems in removing gutta-
percha in curved root canals during root canal retreatment. J
Istanb Univ Fac Dent. 2017;51(2):7-13. http://doi.org/10.17096/
jiufd.97431 PMid:28955590.
22. Haugen HJ, Qasim SB, Matinlinna JP, Vallittu P, Nogueira LP.
Nano-CT as tool for characterization of dental resin composites.
Sci Rep. 2020;10(1):15520. http://doi.org/10.1038/s41598-020-
72599-y PMid:32968120.
23. Nagendrababu V, Murray PE, Ordinola-Zapata R, Peters OA,
Rôças IN, Siqueira JF Jr,etal. PRILE 2021 guidelines for reporting
laboratory studies in Endodontology: A consensus-based
development. Int Endod J. 2021;54(9):1482-90. http://doi.
org/10.1111/iej.13542 PMid:33938010.
24. Solete P, Valan A, Jeevanandan G, Antony S DP, Kavoor S.
Influence of heat-treated retreatment files on the canal
transportation and centering ability during retreatment: an in
vitro cone beam computed tomography study. J Int Oral Health.
2023;15(3):278. http://doi.org/10.4103/jioh.jioh_270_22.
25. Schneider SW. A comparison of canal preparations in straight
and curved root canals. Oral Surg Oral Med Oral Pathol.
1971;32(2):271-5. http://doi.org/10.1016/0030-4220(71)90230-1
PMid:5284110.
26. Sairaman S, Solete P, Jeevanandan G, Antony SDP, Kavoor S,
Adimulapu HS. Comparative analysis of novel heat-treated
retreatment file system on the removal of obturating material
using nano-computed tomography. J Conserv Dent Endod.
2024;27(1):82-6. http://doi.org/10.4103/JCDE.JCDE_224_23
PMid:38389750.
27. Swathi S, Antony DP, Solete P, Jeevanandan G, Vishwanathaiah
S, Maganur PC. Comparative evaluation of remaining dentin
thickness, canal centering ability and apical deformity between
ProFit S3 and Protaper gold – A nano CT study. Saudi Dent J.
2024;36(4):650-5. http://doi.org/10.1016/j.sdentj.2024.01.002
PMid:38690382.
28. Antony SDP, Subramanian AK, Nivedhitha MS, Solete P.
Comparative evaluation of canal transportation, centering ability,
and dentin removal between ProTaper Gold, One Curve, and
Profit S3: an study. J Conserv Dent. 2020;23(6):632-6. http://
doi.org/10.4103/JCD.JCD_619_20 PMid:34083922.
29. Gambill JM, Alder M, del Rio CE. Comparison of nickel-
titanium and stainless steel hand-file instrumentation using
computed tomography. J Endod. 1996;22(7):369-75. http://doi.
org/10.1016/S0099-2399(96)80221-4 PMid:8935064.
30. Gergi R, Rjeily JA, Sader J, Naaman A. Comparison of canal
transportation and centering ability of twisted files, Pathfile-
ProTaper system, and stainless steel hand K-files by using
computed tomography. J Endod. 2010;36(5):904-7. http://doi.
org/10.1016/j.joen.2009.12.038 PMid:20416443.
31. Hasheminia SM, Farhad A, Sheikhi M, Soltani P, Hendi SS,
Ahmadi M. Cone-beam computed tomographic analysis
of canal transportation and centering ability of single-file
systems. J Endod. 2018;44(12):1788-91. http://doi.org/10.1016/j.
joen.2018.09.011 PMid:30390970.
32. Yammine S, Jabbour E, Diemer F, Majzoub Z. Canal straightening
following overinstrumentation with three nickel-titanium rotary
instruments. J Int Soc Prev Community Dent. 2018;8(3):245-51.
http://doi.org/10.4103/jispcd.JISPCD_18_18 PMid:29911063.
33. Peyrin F, Dong P, Pacureanu A, Langer M. Micro- and nano-CT
for the study of bone ultrastructure. Curr Osteoporos Rep.
2014;12(4):465-74. http://doi.org/10.1007/s11914-014-0233-0
PMid:25292366.
34. Huang Y, Celikten B, de Faria Vasconcelos K, Ferreira Pinheiro
Nicolielo L, Lippiatt N, Buyuksungur A, et al. Micro-CT and
nano-CT analysis of filling quality of three different endodontic
sealers. Dentomaxillofac Radiol. 2017;46(8):20170223. http://
doi.org/10.1259/dmfr.20170223 PMid:28845679.
35. Versiani MA, Basrani B, Sousa-Neto MD. The root canal anatomy
in permanent dentition. Cham: Springer; 2018.
36. Schäfer E, Bürklein S. Impact of nickel-titanium instrumentation
of the root canal on clinical outcomes: a focused review.
Odontology. 2012;100(2):130-6. http://doi.org/10.1007/s10266-
012-0066-1 PMid:22527909.
37. Tabassum S, Zafar K, Umer F. Nickel-titanium rotary file systems:
what’s new? Eur Endod J. 2019;4(3):111-7. PMid:32161896.
38. Kandaswamy D, Venkateshbabu N, Porkodi I, Pradeep G.
Canal-centering ability: an endodontic challenge. J Conserv
Dent. 2009;12(1):3-9. http://doi.org/10.4103/0972-0707.53334
PMid:20379433.
9
Braz Dent Sci 2024 July/Sept;27 (3): e4369
Sairaman S et al.
Comparative evaluation of the canal transportation after retreatment with Solite RS3 and Protaper Universal retreatment files: a nano computed tomography study
Sairaman S et al. Comparative evaluation of the canal transportation
after retreatment with Solite RS3 and Protaper Universal
retreatment files: a nano computed tomography study
39. Silva EJNL, Giraldes JFN, de Lima CO, Vieira VTL, Elias CN,
Antunes HS. Influence of heat treatment on torsional resistance
and surface roughness of nickel-titanium instruments. Int
Endod J. 2019;52(11):1645-51. http://doi.org/10.1111/iej.13164
PMid:31132156.
40. Chan W-S, Gulati K, Peters OA. From heat treatment to
surface functionalization for nickel-titanium (NiTi) instruments
in endodontics. Bioact Mater. 2023;22:91-111. http://doi.
org/10.1016/j.bioactmat.2022.09.008 PMid:36203965.
41. Zupanc J, Vahdat-Pajouh N, Schäfer E. New thermomechanically
treated NiTi alloys - a review. Int Endod J. 2018;51(10):1088-103.
http://doi.org/10.1111/iej.12924 PMid:29574784.
42. Silva EJNL, Martins JNR, Lima CO, Vieira VTL, Braz Fernandes FM,
De-Deus G,etal. Mechanical tests, metallurgical characterization,
and shaping ability of nickel-titanium rotary instruments: a
multimethod research. J Endod. 2020;46(10):1485-94. http://
doi.org/10.1016/j.joen.2020.07.016 PMid:32721485.
43. Purba R, Sonarkar SS, Podar R, Singh S, Babel S, Kulkarni G.
Comparative evaluation of retreatment techniques by using
different file systems from oval-shaped canals. J Conserv Dent.
2020;23(1):91-6. http://doi.org/10.4103/JCD.JCD_167_20
PMid:33223649.
44. Shemesh H, Roeleveld AC, Wesselink PR, Wu M-K. Damage
to root dentin during retreatment procedures. J Endod.
2011;37(1):63-6. http://doi.org/10.1016/j.joen.2010.10.002
PMid:21146079.
45. Tamse A, Fuss Z, Lustig J, Kaplavi J. An evaluation of
endodontically treated vertically fractured teeth. J
Endod. 1999;25(7):506-8. http://doi.org/10.1016/S0099-
2399(99)80292-1 PMid:10687518.
46. Ricks-Williamson LJ, Fotos PG, Goel VK, Spivey J, Rivera E,
Khera S. A three-dimensional finite-element stress analysis
of an endodontically prepared maxillary central incisor. J
Endod. 1995;21(7):362-7. http://doi.org/10.1016/S0099-
2399(06)80971-4 PMid:7499976.
47. Touré B, Faye B, Kane AW, Lo CM, Niang B, Boucher Y. Analysis
of reasons for extraction of endodontically treated teeth: a
prospective study. J Endod. 2011;37(11):1512-5. http://doi.
org/10.1016/j.joen.2011.07.002 PMid:22000453.
48. Nikkerdar N, Hatam R, Shahsavand L, Khavid A. The comparison
of the rate of apical displacement in curved root canals using
Neoniti and RaCe files by cone beam CT Scan. Braz Dent
Sci. 2019;22(3):313-20. http://doi.org/10.14295/bds.2019.
v22i3.1748.
49. Bozkurt DA, Terlemez A, Özcan M. Assessment of technical
quality of 9562 endodontic cases treated by undergraduate
students and endodontics specialists. Braz Dent Sci. 2021;24(1):9.
http://doi.org/10.14295/bds.2020.v23i4.2240.
50. Jose J, Kasaragadda A, Siddique R. Comparison of postoperative
pain reduction using continuous rotation glide path system with
other methods of glide path creation-a systematic review. Braz
Dent Sci. 2022;25(2):e2633. http://doi.org/10.4322/bds.2022.
e2633.
Pradeep Solete
(Corresponding address)
Saveetha University, Saveetha Institute of Medical and Technical Sciences,
Saveetha Dental College and Hospitals, Department of Conservative
Dentistry and Endodontics, Chennai, India.
Email: pradeeps@saveetha.com
Date submitted: 2024 Mar 09
Accept submission: 2024 July 16