A comparative evaluation of the sealing ability of 2 root-end

filling materials: an in vitro leakage study using

Enterococcus faecalis
Uma Nair, DMD, MDS,a Simon Ghattas, DMD,b Mohamed Saber, BDS,b
Marianella Natera, DDS,b Clay Walker, PhD,c and Roberta Pileggi, DDS, MS,d Gainesville, FL
UNIVERSITY OF FLORIDA

Objective. The purpose of this study was to evaluate the sealing ability of EndoSequence Bioceramic Root-end Repair
(BCRR) material when compared with white mineral trioxide aggregate (WMTA).
Study design. Forty single-rooted teeth were instrumented, obturated with gutta-percha, root-end resected, and
retrofilled with 2 different materials: white ProRoot MTA (WMTA) (n ⫽ 15) and BCRR (n ⫽ 15). Unfilled specimens
(n ⫽ 10) received no retrofill and were used as controls. All groups received E. faecalis in a created reservoir coronal
to the root filling and the presence of microleakage was evaluated by counting the colony-forming units from each
specimen. The results were analyzed with 1-way analysis of variance.
Results. There was no significant difference in leakage between the 2 experimental groups, but there was a significant
difference with the control (P ⱕ .05).
Conclusions. This study suggests that BCRR is equivalent in sealing ability to WMTA when used as root-end filling
material in vitro. (Oral Surg Oral Med Oral Pathol Oral Radiol Endod 2011;112:e74-e77)

Nonsurgical endodontic treatment has a high success “golden” standard for root-end filling materials.9 MTA
rate.1,2 Adequate preparation and obturation of the root demonstrates superior sealing ability and biocompati-
canal system is key to endodontic success.3,4 Surgical bility compared with other materials9 –11; however,
intervention is indicated when orthograde retreatment poor handling characteristics, initial looseness, and
fails or is contraindicated. The objective of periapical slow setting time make MTA difficult to use.12
surgery is to eliminate diseased tissues and obtain an The manufacturer of a novel material, EndoSequence
apical seal to prevent the ingress of residual irritants BioCeramic Root-end Repair (BCRR), claims compa-
into the periradicular area.5 Resection and retrograde rable physical and mechanical properties to MTA but
preparation of the root canal is followed by placement with superior handling and setting characteristics.
of a material to seal the apical canal anatomy.5 The Leakage remains a priority when evaluating new retro-
ideal materials for root-end fillings should be biocom- grade filling materials.13–15 Based on this premise, the
patible, insoluble, dimensionally stable, and, perhaps aim of this study was to compare, in vitro, the micro-
most importantly, be able to seal the root canal system.6 leakage of BCRR material with MTA as retrograde
An array of restorative materials has been adapted for filling materials using a bacterial leakage model. The
root-end filling, such as amalgam, composite, glass null hypothesis (H0) was that there was no statistically
ionomer, and super-EBA.7 Mineral trioxide aggregate significant difference in bacterial leakage between the 2
(MTA) was introduced specifically for root-end filling materials.
and perforation repair.7,8 It is rapidly becoming the
MATERIAL AND METHODS
a
Assistant Professor, Department of Endodontics, College of Den- Tooth selection and orthograde procedures
tistry, University of Florida. Forty intact, single-canal, freshly extracted human
b
Fellow, Department of Endodontics, College of Dentistry, Univer-
teeth with mature apices were selected for this study.
sity of Florida.
c
Professor, Department of Oral Biology, College of Dentistry, Uni- Initial radiographs were obtained for all teeth. A low-
versity of Florida. speed diamond saw (NSK Z500 brushless motor; Bras-
d
Associate Professor and Chair, Department of Endodontics, College seler USA, Savannah, GA) was used to decoronate the
of Dentistry, University of Florida. teeth to standardize specimen length (12.96 ⫾ 0.37
Received for publication Nov 22, 2010; returned for revision Jan 13, mm). Working length was determined by placing a #10
2011; accepted for publication Jan 22, 2011.
1079-2104/$ - see front matter file into the canal until it was visualized at the apex and
© 2011 Mosby, Inc. All rights reserved. then subtracting 1 mm. Apical preparation was then
doi:10.1016/j.tripleo.2011.01.030 completed with Profile GT files (Dentsply, Tulsa Den-

e74
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Volume 112, Number 2 Nair et al. e75

tal Specialties, Tulsa, OK) to a size 40/0.06. The can- Leakage

als were irrigated with 6.15% sodium hypochlorite 120.00%

Percentage of teeth with leakage

(NaOCl; Chlorox, The Chlorox Co, Oakland, CA) and
100.00%
lubricated with EndoGel (Jordco Inc., Beaverton, OR)
throughout the mechanical preparation. The canals 80.00%

were dried with medium paper points (Henry Schein, 60.00%

Inc., Melville, NY). Leakage
40.00%
Ten specimens were designated as controls: positive
and negative, 5 each. The remaining specimens were 20.00%

obturated with the continuous wave technique. A 0.06- 0.00%

taper Autofit GP cone (Analytical Technology, Glen- BCRR MTA CONTROL

dora, CA) was fitted to working length. Cone fit and Fig. 1. Comparison of percentage of samples with bacterial
length were verified radiographically. The tip of the leakage using WMTA, BCRR, and the positive control.
cone was coated with AH plus sealer (Dentsply
Maillefer, Tulsa, OK) before obturation. A suitable size
system B plugger (SybronEndo, Glendora, CA) was
used to downpack the gutta percha at 5 mm short of the
reservoir for the bacteria (Enterococcus faecalis). In the
working length. The remainder of the canal was back-
experimental and positive control groups, a double
filled with thermoplasticized gutta percha using Obtura
layer of nail varnish was used to seal the entire speci-
III (Obtura-Spartan, Fenton, MO).
men surface except for the apical and coronal aspects;
the specimens of the negative control groups were
Retrograde procedures completely covered.
The apical 3 mm of all specimens was resected, Then, 100 ␮L of trypticase-soy broth was pipetted
under water spray, at a 90-degree angle to the long axis into Eppendorf tubes. Specimens were mounted inside
of the root using a #330 fissure bur (Brasseler USA) the tubes. Five microliters of E. faecalis suspension was
mounted in a high-speed handpiece (KaVo Dental Cor- dispensed into the previously prepared reservoir. The
poration, Charlotte, NC). The apical ends of the roots tubes were incubated in an anaerobic chamber (10%
were prepared with the KiS ultrasonic tips (Obtura- H2, 10% CO2, and balance N2) at 37°C for 7 days. The
Spartan). A cylindrical preparation, 3 mm deep, was broth from each tube was serially diluted 10-fold and
created and rinsed with saline and dried with paper plated on trypticase-soy blood agar and incubated again
points. Suitable size microplugger (Obtura-Spartan) for another 5 days under identical conditions. The mi-
was selected. croleakage was confirmed by the presence of active
Unfilled control specimens (n ⫽ 10) were set aside bacterial growth.
and received no retrofill; the remaining specimens were
randomly assigned to 1 of 2 experimental groups (n ⫽ Statistical analysis
15) according to retro-filling material: Quantitative data were tabulated and analyzed using
● BCRR: EndoSequence BioCeramic Root-end Repair SPSS 16 (SPSS, Inc., Chicago, IL) software. The re-
(Brasseler USA) sults were analyzed using 1-way analysis of variance
● MTA: white ProRoot MTA (Dentsply, Tulsa Dental and Tukey’s post hoc tests for significant differences
Specialties) between groups. Level of significance was set at P less
than or equal to .05.
All materials were prepared according to manufac-
turers’ instructions and condensed in the retroprepara- RESULTS
tions using microplugger. Adequacy of root-end fillings The specimens in the negative control group showed
was verified radiographically both buccolingually and no bacterial growth (0%), whereas the positive control
mesiodistally. All specimens were then stored in a group demonstrated distinct bacterial growth (100%).
humidifier for 7 days to ensure complete setting of the There was no significant difference (P ⬍ .05) in the
materials. number of samples that leaked in the MTA (53.3%) and
the BCRR groups (66.7%) (Fig. 1).
Bacterial leakage model
The experimental set-up used to evaluate the bacte- DISCUSSION
rial microleakage was adapted from a previous study.16 Based on the results of this experiment, the hypoth-
Two millimeters of gutta percha was removed from the esis was accepted. Perhaps the most important predictor
coronal portion of the obturated root canals to create a of success for periapical surgery is the sealing of the
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e76 Nair et al. August 2011

root end. In the past, leakage was assessed using dye secondary infections. Using human saliva is advanta-
penetration methodologies using a variety of pigments, geous to some degree because it closely approximates
such as methylene blue and India and Pelikan ink.15 the real clinical situation; on the other hand, it does not
However, the reliability, reproducibility, and clinical simulate temperature changes, the influence of diet, and
relevance of these methods are questionable.15,17,18 salivary flow.25 The model chosen for this study, al-
Some researchers disagree with the use of such dyes though in vitro, attempted to simulate clinical condi-
because they have low molecular weights and, conse- tions; therefore, E. faecalis was chosen because of ease
quently, can penetrate into sites where protein and of arrangement and interpretation of the data.
bacteria cannot.19 Moreover, dye penetration lacks uni- Under the conditions of this study, there was no
formity around the margins of the root-end filling.20 statistically significant difference between the 2 mate-
The composition of BCRR includes calcium sili- rials. A recent study showed that the cytotoxicity of
cates, zirconium oxide, tantalum pentoxide, calcium BCRR is similar to white and gray MTA.26 The results
phosphate monobasic, and filler agents. Similar to of this study showed a positive performance by BCRR
MTA, BCRR also sets in the presence of moisture. in vitro. However, the literature lacks well-designed,
According to the manufacturer, working time of BCRR prospective clinical studies evaluating this relatively
is about 30 minutes and setting time is about 4 hours new bioceramic material. Clinicians should remain
under normal conditions. However, it may take up to 12 skeptical until a sufficient body of research becomes
hours under extremely dry conditions. The principal available.
components of MTA are tricalcium silicate, bismuth
oxide, dicalcium silicate, tricalcium aluminate, tetracal-
cium aluminoferrite, and calcium sulfate dihydrate. By REFERENCES
1. Lazarski MP, Walker WA 3rd, Flores CM, Schindler WG, Har-
weight it is 75% Portland cement, 20% bismuth oxide,
greaves KM. Epidemiological evaluation of the outcomes of
and 5% gypsum. MTA is marketed as ProRoot MTA. nonsurgical root canal treatment in a large cohort of insured
According to the manufacturer, the setting time is 4 dental patients. J Endod 2001;27:791-6.
hours. 2. Salehrabi R, Rotstein I. Endodontic treatment outcomes in a
Torabinejad et al.21 showed that, in 23% of speci- large patient population in the USA: an epidemiological study. J
mens, MTA promoted cementum formation within 2 to Endod 2004;30:846-50.
3. Schilder H. Cleaning and shaping the root canal. Dent Clin North
5 weeks after periapical surgery and more than 80% of Am 1974;18:269-96.
the root-end cavities filled with MTA showed cemen- 4. Schilder H. Filling root canals in three dimensions. Dent Clin
tum deposition 10 to 18 weeks after surgery. Other North Am 1967:723-44.
studies on monkeys established MTA’s superiority 5. Kim S, Kratchman S. Modern endodontic surgery concepts and
(less inflammation and cementum formation at 5 practice: a review. J Endod 2006;32:601-23.
6. Johnson BR. Considerations in the selection of a root-end filling
months) over amalgam as a root-end filling material.
material. Oral Surg Oral Med Oral Pathol Oral Radiol Endod
MTA was the most favorable in terms of degree of 1999;87:398-404.
polymorphonuclear infiltration, bone maturation, and 7. Adamo HL, Buruiana R, Schertzer L, Boylan RJ. A comparison
cementum formation.22 In a prospective case series of MTA, Super-EBA, composite and amalgam as root-end filling
study on 276 teeth with white MTA as a root-end filling materials using a bacterial microleakage model. Int Endod J
material, Saunders23 reported 88.8% clinical and radio- 1999;32:197-203.
8. Daoudi MF, Saunders WP. In vitro evaluation of furcal perfora-
graphic success after 4 to 72 months. He concluded that
tion repair using mineral trioxide aggregate or resin modified
using careful microsurgical techniques combined with glass ionomer cement with and without the use of the operating
MTA as a root-end filling material resulted in higher microscope. J Endod 2002;28:512-5.
success rates for apical surgery. A meta-analysis of 30 9. Bodrumlu E. Biocompatibility of retrograde root filling materi-
articles indicated that MTA has a high clinical success als: a review. Aust Endod J 2008;34:30-5.
rate, provides the best seal, shows superior biocompat- 10. Bates CF, Carnes DL, del Rio CE. Longitudinal sealing ability of
mineral trioxide aggregate as a root-end filling material. J Endod
ibility, and is the only root-end filling material that
1996;22:575-8.
promotes tissue regeneration when compared with 11. Roberts HW, Toth JM, Berzins DW, Charlton DG. Mineral
amalgam, intermediate restorative material (IRM), and trioxide aggregate material use in endodontic treatment: a review
Super EBA.24 of the literature. Dent Mater 2008;24:149-64.
The rationale behind using the E. faecalis strain of 12. Ber BS, Hatton JF, Stewart GP. Chemical modification of Pro-
bacteria in this study was for several reasons. One Root MTA to improve handling characteristics and decrease
setting time. J Endod 2007;33:1231-4.
reason E. faecalis was chosen was because it is a part of
13. Saghiri MA, Lotfi M, Saghiri AM, Vosoughhosseini S, Fatemi A,
the normal oral flora in humans and is found frequently Shiezadeh V, et al. Effect of pH on sealing ability of white
in mixed infections. E. faecalis is also one of the most mineral trioxide aggregate as a root-end filling material. J Endod
commonly isolated microbes from the root canal in 2008;34:1226-9.
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Volume 112, Number 2 Nair et al. e77

14. Torabinejad M, Rastegar AF, Kettering JD, Pitt-Ford TR. Bac- 23. Saunders WP. A prospective clinical study of periradicular sur-
terial leakage of mineral trioxide aggregate as a root-end filling gery using mineral trioxide aggregate as a root-end filling. J
material. J Endod 1995;21:109-12. Endod 2008;34:660-5.
15. De Bruyne MA, Verhelst PC, De Moor RJ. [Critical analysis of 24. Fernandez-Yanez-Sanchez A, Leco-Berrocal MI, Martinez-Gon-
leakage studies in endodontics]. Rev Belge Med Dent zalez JM. Metaanalysis of filler materials in periapical surgery.
2005;60:92-106. Med Oral Patol Oral Cir Bucal 2008;13:E180-5.
16. Siqueira JF Jr, Rocas IN, Abad EC, Castro AJ, Gahyva SM, 25. Siqueira JF Jr, Rocas IN, Lopes HP, de Uzeda M. Coronal
Favieri A. Ability of three root-end filling materials to prevent leakage of two root canal sealers containing calcium hydroxide
bacterial leakage. J Endod 2001;27:673-5. after exposure to human saliva. J Endod 1999;25:14-6.
17. Wu MK, Wesselink PR. Endodontic leakage studies reconsid- 26. Alanezi AZ, Jiang J, Safavi KE, Spangberg LS, Zhu Q.
ered. Part I. Methodology, application and relevance. Int Endod Cytotoxicity evaluation of endosequence root repair material.
J 1993;26:37-43.
Oral Surg Oral Med Oral Pathol Oral Radiol Endod 2010;
18. AliGhamdi A, Wennberg A. Testing of sealing ability of end-
109:e122-5.
odontic filling materials. Endod Dent Traumatol 1994;10:249-55.
19. Barthel CR, Moshonov J, Shuping G, Orstavik D. Bacterial
leakage versus dye leakage in obturated root canals. Int Endod J
1999;32:370-5. Reprint requests:
20. Camps J, Pashley D. Reliability of the dye penetration studies. J
Endod 2003;29:592-4. Uma Nair, DMD, MS
21. Torabinejad M, Hong CU, Lee SJ, Monsef M, Pitt-Ford TR. Assistant Professor
Investigation of mineral trioxide aggregate for root-end filling in University of Florida
dogs. J Endod 1995;21:603-8. College of Dentistry
22. Torabinejad M, Pitt-Ford TR, McKendry DJ, Abedi HR, Miller 1600 SW Archer Road
DA, Kariyawasam SP. Histologic assessment of mineral trioxide D10-37, PO Box, 100436
aggregate as a root-end filling in monkeys. J Endod 1997; Gainesville, FL 32610-0436
23:225-8. unair@dental.ufl.edu