Received: 5 October 2016
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Revised: 14 January 2017
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Accepted: 18 February 2017
DOI 10.1002/jemt.22861
RESEARCH ARTICLE
Sealing ability and adaptation of root-end filling materials in cavities prepared with different techniques € € rduysus1,2 | Cem Şahin3 € çu €kkaya Eren1 | Mehmet Omer Selen Ku Go 1 Faculty of Dentistry, Department of Endodontics, Hacettepe University, Ankara, Turkey 2
College of Dental Medicine, Department of Preventive and Restorative Dentistry, University of Sharjah, Sharjah, United Arab Emirates 3
School of Health Services, Dental Prosthetics Technology, Hacettepe University, Ankara, Turkey
Abstract The aim of this study was to evaluate the sealing ability and marginal adaptation of calcium silicate-based cements (CSCs) in root-end cavities prepared by ultrasonic and laser tips. A total of 72 extracted human maxillary incisor teeth were randomly divided as 60 teeth in experimental groups and 6 teeth each for positive and negative control groups. Specimens in experimental groups were obturated, their root-end resections were performed and randomly divided into six groups (n 5 10) as follows: G1: Ultrasonic retrotip 1 MTA, G2: Ultrasonic retrotip 1 Calcium Enriched Mixture (CEM), G3: Ultrasonic retrotip 1 Biodentine, G4: Er:YAG laser tip 1 MTA, G5:
Correspondence Selen K€ uç€ ukkaya Eren, DDS, PhD, Hacettepe University, Faculty of Dentistry, Department of Endodontics, 06100, Ankara, Turkey. Email:
[email protected]
Er:YAG laser tip 1 CEM, G6: Er:YAG laser tip 1 Biodentine. The sealing ability was measured by
Funding information Hacettepe University Scientific Research Fund; Grant number: 013D05201001
man correlation coefficient tests. No significant difference was found between materials
fluid transport method. Six specimens from each experimental group were randomly selected to analyze marginal adaptation and prepared for scanning electron microscopy (SEM) analysis. Micrographs were scored and also analyzed using Image J software. Data were analyzed with; two-way ANOVA, Bonferroni, Kruskall–Wallis, Mann–Whitney-U, Siegel & Castellan, and Spearregarding the sealing ability and marginal adaptation (p > 0.05). Significantly greater fluid movement and poor marginal adaptation were seen for materials placed in cavities prepared by laser tips (p < 0.05). Positive correlation was found between the results of scoring and Image J analysis of SEM images (r 5 0.596, p < 0.001). Fluid transport method and SEM analysis gave similar results suggesting the use of ultrasonic-retrotips for preparing root-end cavities which are going to be filled with one of these CSCs.
KEYWORDS
calcium silicate, endodontic surgery, laser, SEM, ultrasonic
1 | INTRODUCTION
recommended for root-end filling because of its good physical and chemical properties (Torabinejad, Hong, McDonald, & Pitt Ford, 1995).
Periapical surgery is a viable treatment option in the presence of persis-
MTA appears to be the most promising material to date, as it comes
tent periradicular pathosis or when orthograde retreatment is consid-
closest to being the ideal material for root-end filling. However, MTA
ered unfeasible (Gutmann & Harrison, 1985). Because root-end cavity
has some drawbacks such as a long setting time and difficult handling
preparation and sealing ability of root-end filling materials are essential
characteristics (Parirokh & Torabinejad, 2010). On the other hand, it
components of periapical surgery, obtaining a hermetic seal has been a
has been reported that a commercial brand of MTA (Angelus, Londrina,
concern, which has led to the development of new materials and tech-
PR, Brazil) has a setting time of 15 min (Santos, Araujo, Yukimitu, Bar-
niques that allow the complete and three-dimensional sealing of the
bosa, & Moraes, 2008). Recently, new materials have been developed
root-end cavity (Kim & Kratchman, 2006).
to be used for similar indications with MTA. Biodentine (Septodont,
Mineral trioxide aggregate (MTA), a calcium silicate-based cement
SaintMaur-des-Fosses, France), a more recent CSC, was introduced as
(CSC), was developed (Torabinejad, Watson, & Pitt Ford, 1993) and
a dentin substitute under resin composite restorations (Laurent, Camps, De Meo, Dejou, & About, 2008) and reported to exhibit short setting
Review Editor: Prof. Alberto Diaspro
Microsc Res Tech. 2017;1–7
time and high mechanical properties (Grech, Mallia, & Camilleri, 2013).
wileyonlinelibrary.com/journal/jemt
C 2017 Wiley Periodicals, Inc. V
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Calcium Enriched Mixture (CEM cement, BioniqueDent, Tehran, Iran) is another recently introduced endodontic material which is composed of
Root-end cavity preparation techniques and filling materials in experimental groups
T A B LE 1
several calcium compounds (Asgary, Shahabi, Jafarzadeh, Amini, &
Ultrasonic tip-prepared root-end cavities
Laser tip-prepared root-end cavities
MTA (Angelus, Londrina, PR, Brazil)
G1 (n 5 10)
G4 (n 5 10)
CEM (BioniqueDent, Tahran, Iran)
G2 (n 5 10)
G5 (n 5 10)
Biodentine (Septodont, s, France) Saint Maur des Fosse
G3 (n 5 10)
G6 (n 5 10)
Kheirieh, 2008) and was reported to have good handling characteristics, an ability to form hydroxyapatite in contact with tissue fluid (Asgary, Eghbal, Parirokh, & Ghoddusi, 2009), and superior antibacterial properties to that of MTA (Asgary, Akbari Kamrani, & Taheri, 2007). Development of ultrasonic-retrotips for root-end cavity preparation has significantly improved the prognosis of surgery as they have a number of advantages including their smaller dimensions and improved access to the resected root-end cavities (Kim & Kratchman, 2006).
ET AL.
Root-end filling materials
However, ultrasonic-retrotips have been associated with high incidence of cracks in dentine wall during preparation (Saunders, Saunders, & Gutmann, 1994). The cavity preparation with Erbium:YAG (Er:YAG)
resected roots were randomly divided into six experimental groups
laser has recently drawn attention because its speed of ablation of the
according to the cavity preparation technique and filling material used
hard dental tissues, lack of vibration, lower possibility of operating field
(Table 1). All root-end cavities were prepared to a depth of 3 and 1 mm
contamination, and lowered risk of traumatizing the surrounding tis-
in diameter confirmed with a periodontal probe. In ultrasonic groups,
sues (Karlovic et al., 2005; van As, 2004).
root-end cavities were prepared with diamond-coated retrotips (E32D
Using different techniques for root-end cavity preparations may
tip, NSK, Satelec, France) on a piezoelectric unit (Pmax, Satelec,
affect the sealing ability and marginal adaptation of filling materials.
Merignac, France) at a medium-power setting with distilled water irri-
Therefore, the aims of the present study were to evaluate the sealing
gation. In laser groups, root-end cavities were prepared with Er:YAG
ability and marginal adaptation of MTA, Biodentine, and CEM in root-
laser (Fotona AT Fidelis, Ljubljana, Slovenia) in contact mode with 600
end cavities prepared by ultrasonic and laser tips and to determine
mm laser-tips in diameter and a setting of 180 mJ pulse energy, 10 Hz
whether a correlation exists between the sealing ability test and scan-
pulse rate, 1.8 W power, 2940 nm wavelength, 45% distilled water and
ning electron microscopy (SEM) evaluation of marginal adaptation.
55% air. Each tip was used for five root-end preparations. The rootend cavities were filled with the filling materials which were prepared
2 | MATERIALS AND METHODS
according to the manufacturer’s instructions. All teeth were stored at 37 8C and 100% humidity for 24 hr.
Seventy-two single-rooted human maxillary incisors with straight roots and fully-developed apices were collected following the University ethical committee approval (GO-13/106). Six teeth were randomly selected for the negative control group and left untreated. The crowns of remaining 66 teeth were sectioned to obtain a standardized length of 15 mm. The working length was established by taking a #15 K file (Dentsply Maillefer, Ballaigues, Switzerland) until the apical foramen and then subtracting 1 mm. The root canals were instrumented using a crown-down technique with ProTaper rotary instruments (Dentsply, Maillefer) to a final file of F4 with a 0.40 mm tip diameter and a 6% apical third taper, and irrigated with 1 mL 2.5% sodium hypochlorite (NaOCl) between each instrument. Final irrigation was performed with 5 mL 5.25% NaOCl followed by 5 mL 15% ethylenediaminetetraacetic acid (EDTA) to remove the smear layer. Finally, the specimens were irrigated with 10 mL distilled water and subsequently dried with paper points. At this point, randomly selected 6 teeth were left untreated and used for positive controls. The root canals of 60 specimens were obturated using cold lateral compaction of size F4 ProTaper cone (Dentsply,
2.1 | Assessment of sealing ability The external surface of each tooth in experimental groups was coated with two layers of the nail varnish, except for the access opening and the apical foramen. The teeth in negative control group were completely covered with nail varnish. A modified fluid transport test method was applied to measure the sealing ability of filling materials (Fogel, 1995). The sealing ability was quantified by following the movement of a tiny air bubble traveling within a constant bore a 100-lL micropipette (Figure 1). The water movement displacing the air bubble in the capillary tube was measured per unit of time. Linear displacement of this air bubble was converted to volume displacement and was recorded as the fluid transported. The values were expressed as lL/ min/cm H2O. The fluid transport results were analyzed statistically with two-way ANOVA and Bonferroni tests at p < 0.05.
2.2 | Marginal adaptation
Maillefer) with accessory gutta-percha cones and AH-26 sealer (Dents-
Following the fluid transport test, six specimens from each experimen-
ply, Maillefer). All teeth were stored at 37 8C and 100% humidity for
tal group were randomly selected and a total of 36 specimens were
1 week.
prepared for SEM evaluation using the protocol described by Rosa
Apical root resections were performed on the obturated roots by
et al. (2014). Briefly, the apical 5 mm of each root was transversally
removing 3 mm of each apex perpendicular to the long axis of the root
sectioned with a diamond disc. Next, the blocks were longitudinally
with fissure bur at high speed under continuous water spray. The
sectioned so that the section did not reach the root canal. Then, each
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FIGURE 1
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ET AL.
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Schematic drawing of the test apparatus used to measure fluid transport along the obturated root canals. DW: Distilled water
specimen was sanded using water-wet sandpaper in a polishing
3 | RESULTS
machine to exposure the area of interest. The specimens underwent to slow dehydration with silica gel, mounted onto specific stubs, gold
The positive control group showed the highest fluid transport values
sputtered (Sputter Coater; SPI, Toronto, Canada) for SEM (JEOL 6400,
(1428 lL/min/cmH2O), whereas no fluid transport was recorded in the
JEOL Corporation, Tokyo, Japan) evaluation. The electron micrographs
negative control group. This confirmed the reliability of the test appara-
were obtained with 1303 magnification. Then, the adaptation of root-
tus. The fluid transport values of experimental groups are displayed in
end filling materials to cavity walls was assessed both qualitatively and
Figure 2. Regardless of the cavity preparation technique used, no sig-
quantitatively. Qualitative measurement was done based on a scale
nificant difference was found between materials (p > 0.05). However,
that classified the presence and the extent of marginal gaps in four
the tested cavity preparation techniques had significant effect on over-
scores (Table 2). Two previously calibrated observers analyzed the
all fluid transport values (p < 0.05). Significantly greater fluid movement
images independently. When a difference occurred in the scoring of an
was found in laser tip-prepared cavities (p < 0.05). Similarly, according
image, the two examiners reevaluated the image and discussed it until
to the marginal adaptation results there were no significant differences
an agreement was obtained.
between materials in regards of scores and gap measurements
Quantitative analysis of electron micrographs was made using a
(p > 0.05). However, all materials showed significantly higher scores
software program (ImageJ 1.47 V, National Institute of Health, USA).
and more gaps in laser-prepared cavities compared to ultrasonically
Initially, the software’s measurement tools were calibrated to present
prepared cavities (p < 0.05) (Table 3). Positive correlation was found
the measures in mm2. Thereafter, the overall area of the apical third
between the results of scoring and Image J analysis (r 5 0.596, p
