This study compared the preparation of long-oval root canals using the Reciproc single-file reciprocating system versus the BioRace multiple-file rotary system through micro-computed tomography. Distal root canals of mandibular molars were instrumented with either Reciproc R40 or BioRace BR0-BR4 files and scanned before and after preparation. The Reciproc system removed more dentin volume in the entire canal and apical third, but left more untouched canal surface areas in the middle and cervical thirds compared to BioRace. Neither system was able to fully prepare the long-oval canal shape. The Reciproc system removed more tooth structure while BioRace left fewer untreated areas in the more oval regions of

1. DOS
SANTOS,
M;
BUSQUIM,
SSK;
CUNHA,
RS;
FREIRE,
LG.
Micro-Computed Tomography Evaluation of the Preparation of Long-Oval Root Canals Comparing
the Reciproc and BioRace Systems
Root
canals
that
have
a
long-­‐oval
cross-­‐sec0on
hinder
the
ac0on
of
rota0ng
instruments,
which
cannot
adapt
to
all
extensions
of
the
root
canal
walls.
Newly
developed
single-­‐file
systems
claim
to
prepare
any
type
of
root
canal
with
only
one
instrument.
The
purpose
of
the
present
study
was
to
compare
the
prepara0on
of
long-­‐oval
root
canals
with
a
single
reciproca0ng
system
and
a
mul0ple-­‐file
rotary
system
using
micro-­‐computed
tomography.
Distal
canals
of
thirty
mandibular
molars
were
selected
and
assigned
into
two
groups
(n=15):
Reciproc
40
(VDW,
Munich,
Germany)
and
BioRace
System
(FKG
Dentaire,
La
Chaux-­‐de-­‐Fonds,
Switzerland).
Teeth
were
scanned
before
and
aTer
prepara0on
of
the
root
canals
by
a
SkyScan
1172
micro-­‐computed
tomography
scanner
at
11µm
resolu0on.
Morphometric
varia0ons
were
measured
by
volume
increases
and
by
the
remaining
untreated
canal
surface
area
in
the
en0re
canal
and
each
third.
Data
was
compared
using
the
Mann-­‐Whitney
test.
The
Reciproc
system
was
found
to
have
the
highest
increase
in
volume
when
analyzing
both
the
en0re
canal
and
the
apical
third
(p<0.5).
In
spite
of
that,
it
leT
more
untouched
areas
(p<0.001)
in
the
cervical
and
middle
thirds
(18,14%
and
21.82%)
as
compared
to
BioRace
(8.14%
and
11.35%).
In
conclusion,
neither
technique
was
able
to
completely
prepare
the
long-­‐oval
outline
of
root
canals.
The
Reciproc
system
removed
more
tooth
structure
while
BioRace
leT
fewer
untouched
den0n
walls
in
the
more
oval
thirds
of
the
canal.
PR
74
University
of
Sao
Paulo/Brazil
-­‐
School
of
Den0stry
-­‐
Den0stry
Science
Postgraduate
Program
Area
of
Concentra0on:
Endodon0cs
5mm
CTAn:
Region
of
Interest
(A);
Image
Binarisa0on
(B);
Custom
Processing
Tool
(C)
Volume
Increases
Untreated
Canal
Surface
Area
Reciproc
BioRace
Root
Canal
Prepara0on
Reciproc
R40
BioRace
BR0
a
BR4
1st
Scan
2
n
d
S
c
a
n!
Assessment
of
Morphometric
VariaMons
Volume
Increases
(CTAn)
Untreated
Surface
Area
(MatLab)
Long-­‐oval
Root
Canal
msantos@usp.br
Supported
by
FAPESP
–
Process
11/50996-­‐0