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Basic Research—Technology

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ealing Ability of Three Materials in the Orifice of Rootanal Systems Obturated With Gutta-Percha

tephen Jenkins, DDS, James Kulild, DDS, MS, Karen Williams, RDH, MS, PhD, William Lyons,nd Charles Lee, DDS

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bstracthere were 130 single roots randomly assigned to onef 12 experimental or two control groups. Forty spec-

mens each were sealed with 1, 2, 3, or 4 mm of Cavit,roRoot MTA, or Tetric. After creation of a uniformrifice diameter, the smear layer was removed and theanal systems obturated using warm lateral compactionf gutta-percha (GP). GP was removed to the experi-ental depth, experimental materials placed in therifice, and roots submerged in India ink in a vacuumlask. Specimens were demineralized and leakage mea-ured using a 10� stereomicroscope and graded forepth of leakage by one calibrated, blinded rater. Thereas no significant interaction (p � 0.05) between testaterials and orifice depths, nor main effect of orifice

epth (p � 0.05). However, there was a statisticallyignificant main effect of test materials with Tetricemonstrating a significantly better seal than Pro Rootr Cavit (p � 0.0001) irrespective of orifice depth. (Jndod 2006;32:225–227)

ey Wordsoronal microleakage, coronal seal, intraorifice seal,rifice seal

From the Department of Endodontics, UMKC School ofentistry, Kansas City, Missouri.

Address correspondence to James Kulild, DDS, MS, UMKCchool of Dentistry, Professor and Director, Postgraduate End-dontics, 650 E. 25th Street, Kansas City, MO 64108. E-mailddress: kulildj@umkc.edu.099-2399/$0 - see front matter

Copyright © 2006 by the American Association ofndodontists.oi:10.1016/j.joen.2005.10.042

m

OE — Volume 32, Number 3, March 2006

oronal microleakage can produce complete bacterial penetration of nonsurgical rootcanal treatment (1,2). Furthermore,knowledgeof thenumberand locationof eachroot

anal orifice is important in nonsurgical root canal therapy (3). Perhaps the use of a materialo seal the orifice, in addition to the temporary restoration, could mitigate this bacterialeakage if that temporary restoration was lost or became unserviceable.

Studies of orifice sealers have addressed ease of placement, ability to provide an ade-uate seal, and ease of removal; but all have evaluated materials placed to the same depth (4,). Without an adequate seal, long term success remains questionable (6) and failure toaintain the seal may expose obturated canals to microbes that could retard healing and

reate infection in the periodontal ligament or supporting osseous structures.Kakehashi et al. reported, through exposure of rat pulps, that presence of bacteria in

he oral cavity contributes to the development of apical periodontitis (7). Vire reported that9.4% of endodontically treated teeth failed because of lack of an adequate restoration (8).alto reported that IRM, Cavit, and Dyract all demonstrated leakage when used as a tempo-ary restoration (9). Schwartz et al. reviewed techniques and important strategies for tem-orization and final restoration of the access cavity with bonded materials (10). Somenvestigators have reported that significant coronal microleakage occurred when gutta-per-ha and sealer were used to obturate the root canal system, and then exposed to artificialaliva and India ink from 3 to 56 days. This leakage extended almost the complete length ofhe root canal system (1, 2).

Roghanizad reported that 3 mm of Cavit, TERM, or amalgam placed in the orificeemonstrated less leakage than the positive control group, without an orifice seal, whenxposed to methylene blue for 2 weeks (4). Pisano placed 3.5 mm of Cavit, IRM, or Super-BA in the orifice of obturated root canals (5) and these teeth were exposed to saliva for 90ays and evidence of leakage was indicated by presence of absence of turbidity. All of thebturated, but unsealed, teeth leaked at 49 days, whereas 35% of the IRM and Super-EBA and5% of the Cavit specimens demonstrated leakage.

Thus, the addition of another barrier between the oral environment and the root canalystem, at a depth yet to be determined, appeared to have a positive effect in reducing leakagend increasing possibilities for success. The purpose of this investigation was to examine thentraorifice sealing ability of three experimental materials at four different thicknesses afterbturation of the root canal system.

Materials and MethodsThere were 130 single-rooted teeth, with single root canal systems, stored at 100%

umidity used. Before random assignment to groups, all teeth were cleansed, shaped, andbturated by the primary investigator (PI). Crowns were removed at the cementoenamel

unction. All teeth were transilluminated under a dental operating microscope (Global Sur-ical Corporation, St. Louis, MO) and any tooth with a fracture was excluded. A #10 K-fileKerr Corp, Orange, CA) was inserted and advanced until it was visualized at the apicaloramen. The file was retracted 1 mm and working length was established at this level. AroTaper SX file (Dentsply/Tulsa Dental Products, Tulsa, OK) was used to flare the orifice.ne milliliter of 5.25% NaOCl (Clorox, Oakland, CA) was used between each instrument viaProRinse Periodontal/Endodontic Irrigating Probe (Dentsply/Tulsa Dental Products,

ulsa, OK). ProTaper S1, S2, F1, F2, and F3 files was used sequentially per manufacturer’snstructions in a crown down technique. A 0.04 taper #35 and #40 ProFile (Dentsply/Tulsaental Products) were used to complete instrumentation. A uniform orifice diameter of 1.3

m, at its widest point, was made using a #5 Gates Glidden bur (Dentsply/Tulsa Dental

Ability of Sealing Materials Used in Root Canal Systems 225

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roducts) to a depth of 6 mm. Once instrumentation was completed, theanal was rinsed with two ml of 5.25% NaOCl, followed by 2 ml of 17%thylenediaminetetraacetic acid (Moyco Union Broach, York, PA), and withfinal rinse of 95% ethanol (Sigma, St. Louis, MO). Canals were dried withexicon sterile paper points (Dentsply/Tulsa Dental Products) followed byive seconds of air with a Micro-Air Unit (ASI Medical Inc., Englewood, CO)ia 0.014 mm Capillary Tip (Ultradent, South Jordan, UT). Warm lateralompaction with the Endotec II (Medidenta, Woodside, NY) per manufac-urer’s instructions was accomplished with Lexicon 0.04 gutta-perchaoints (Dentsply/Tulsa Dental Products) and ThermaSeal Plus (Dentsply/ulsa Dental Products).

There were 120 teeth randomly divided among three experimentalroups, with the remaining ten teeth being divided equally betweenositive and negative controls. The three experimental groups wereurther subdivided into four groups.

Group 1: Forty single-rooted teeth, randomly divided into fourgroups of 10 teeth each. Cavit (3M ESPE, St. Paul, MN) was usedto seal the canal orifice at depths of 1, 2, 3, or 4 mm in the orifice.

Group 2: Forty single-rooted teeth, randomly divided into fourgroups of 10 teeth each. ProRoot MTA (Dentsply/Tulsa DentalProducts) was used to seal the canal orifice at depths of 1, 2, 3,or 4 mm in the orifice.

Group 3: Forty single-rooted teeth, randomly divided into fourgroups of 10 teeth each. Tetric (Ivoclar Vivadent, Amherst, NY)was used to seal the canal orifice at depths of 1, 2, 3, or 4 mm inthe orifice.

Positive Control: Five instrumented and obturated teeth with gutta-percha at the level of the orifice.

Negative control: Five instrumented and obturated teeth with threecoats of nail polish (Revlon, New York, NY) sealing the entiretooth.

The PI used the System B (SybronEndo, Orange, CA) to remove gutta-ercha to the experimental depth and verified the depth with a North Caro-

ina periodontal probe (Hu-Friedy, Chicago, IL). Cavit (3M ESPE, St. Paul,N), ProRoot MTA (Dentsply/Tulsa Dental Products), and Tetric (Ivoclar

ivadent), were placed into the orifice per manufacturer’s directions (Fig.). Each tooth was placed into a coded container and stored at 100%umidity for 48 hours to allow for sealer, Cavit, and MTA to set. Tetric is a

ight cured resin, but was exposed to 100% humidity for 48 hours to main-

igure 1. Experimental model.

ain consistency of treatment with the other experimental materials. F

26 Jenkins et al.

Three layers of nail polish (Revlon) were placed on all experimentaleeth coating their root surface from root apex to the level of the cementoe-amel junction. Positive controls were obturated, but not coated with nailolish. Negative controls were obturated and completely coated with nailolish, including the orifice.

Samples were submerged in a vacuum flask containing India inkSigma), subjected to vacuum pressure of 75 torr for 30 minutes, andemained in the dye for seven days (11). After exposure to the dye, samplesere rinsed with running water to remove ink from the external surface. Nailolish was gently removed with a #15 disposable safety scalpel (Miltex, Inc.,ethpage, NY). They were demineralized in 5% nitric acid (Sigma) for 5ays, with daily changes of acid (12) and dehydrated in ascending percent-ges of ethyl alcohol (Sigma). The samples were first placed in individualontainers with 5 ml of 80% alcohol for 12 hours, replaced with 5 ml of 90%lcohol for 2 hours, and replaced with 100% alcohol for 2 more hours. Toomplete the clearing process, the roots were stored in 6 ml of methylalicylate (Sigma) (13). The experimental materials were observed 360egrees and leakage was measured by a calibrated examiner to the greatestenetration using a 10� stereomicroscope (Zeiss, Thornwood, NY) fromhe coronal extent of the orifice material to the nearest 0.1 mm.

Data were analyzed using both descriptive and inferential statistics.o assess the interaction and main effects of test materials and orificeepth on depth of leakage, a two-factor ANOVA was used.

ResultsPositive controls leaked at least 5 mm into the gutta-percha, and no

eakage was observed in the negative control group.Figure 2 shows mean depth of penetration, in millimeters, for each

aterial at various orifice depths. This figure demonstrates orifice prepa-ation depth (x axis) versus the amount of leakage at each orifice depth (yxis).

ANOVA showed no statistically significant interaction (p � 0.05) be-ween test materials and orifice depths, nor main effect of orifice depth (p�.05). However, there was a statistically significant main effect of test mate-ials. Tetric, at 1.49 mm mean penetration, demonstrated a significantlyetter seal than Pro Root, at 2.30 mm mean penetration, or Cavit, at 2.6 mmean penetration, irrespective of orifice depth (p � 0.0001) (Table 1).

valuation of the effect size showed that type of material explained approx-mately 28% of leakage between groups, irrespective of orifice depths (�2)

.279).

DiscussionThe results of this study indicated that, at all depths, Tetric demon-

trated a significantly better seal than either MTA or Cavit. Leakage extended

igure 2. Estimated marginal means of depth of penetration.

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Basic Research—Technology

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he entire length of all the experimental materials into the gutta-percha at thehallowest depth, i.e. 1 mm. However, leakage of Tetric was less than thether experimental materials at all experimental depths. Placement tech-ique or sealing ability of the bonded composite were two possible factors

or why Tetric leaked less than the other materials. Leakage, as a result ofime, was not measured in this study, but could also be a factor. Urangaeported that Tetric did not demonstrate any leakage, whereas Cavit leakedignificantly more than the other experimental materials (14).

Tetric is a material that requires etching and use of a bonding agentefore placement, but placement is still accomplished in approximately 2inutes. Davalou found that a bonded coronal seal of either core paste and

enure, or amalgam and Panavia, resulted in virtually no penetration (15).hey also suggested that smear layer removal may have a direct influence on

he success of the seal of a bonded resin (15). Because Tetric is a flowableomposite, placement was easy. Wells reported that a secondary seal with aesin was both clinically easy and provided a good seal (16). Furthermore,hile Tetric was expensive ($70.00 box/20 carps), very little material was

equired and it exhibited a contrasting shade to dentin. Although the intents not to remove the orifice seal, the gutta-percha could be seen translucentlyhrough the Tetric at all depths and Tetric was easily removed with ultrason-cs. The intent of an orifice seal is to be a definitive barrier of each root canalystem. If post placement, or alternative core material, is to be placed in theoot canal systems, the referring dentist can request that the orifice seal note placed, or he can request the endodontist to place the post and coreaterial. Tetric was used in this investigation because it is representative ofcomposite used by many practitioners and was also in a prior investigation14).

Mineral trioxide aggregate (MTA) leaked significantly more than theetric, was the most expensive material ($249.00/kit), the most difficult toix consistently, and placement was more time consuming (3 min) than the

ther materials. Hardy found that a secondary seal was required over MTAn furcation restorations to minimize leakage (17). MTA was easily dis-erned from dentin and easy to remove with ultrasonics.

Cavit leaked more than either MTA or Tetric. While inexpensive$4.00/tube), Cavit was very easy to place (1 min). Given that the resultsemonstrated more leakage with 2 mm of material than with 1 or 3 mm,avit did not appear to provide a consistent seal. In fact, Cavit did not retard

eakage until 3 mm of material was placed in the orifice. Webber stated that.5 mm of material to be the minimum thickness required in coronal res-

orations to prevent leakage (18). Our study demonstrated leakage at evenmm of material. Removal of Cavit was the easiest.

The results of this study indicated that Tetric may have potential torovide an effective additional barrier to leakage at all depths studied. How-ver, this study used India Ink for only 7 days. Öztan demonstrated India Ink

ABLE 1. Comparison of marginal means of depth of penetration for materialsroups

Group Mean StandardError

95% ConfidenceInterval

LowerBound

UpperBound

Cavit 2.64 .15 2.33 2.95ProRoot 2.26 .16 1.93 2.58Tetric 1.49* .15 1.19 1.79

Statistically significantly less than other two groups (p � 0.0001).

o be superior to methylene blue as it does not stain dentin, does not ad-2

OE — Volume 32, Number 3, March 2006

ersely affect root canal sealers, and only demonstrates penetration of thenk, and not an ink and sealer mixture (19). Siqueira has demonstrated thatemporary and core build-up fillings exposed to human saliva resulted ineakage (20). Salehrabi reported that the majority of extracted endodonti-ally treated teeth lacked a full coverage restoration (21). Thus, the addedenefit of an orifice barrier to reduce coronal leakage may help in retainingndodontically treated teeth. However, further research such as a long-termtudy using other composites, or use of bacteria, may provide a better basisor a true clinical study.

AcknowledgmentThis investigation was supported totally through the generous

upport of the Research Support Committee, UMKC School of Den-istry.

References1. Swanson K, Madison S. An evaluation of coronal microleakage in endodontically

treated teeth. Part I: time periods. J Endod 1987;13:56 –9.2. Madison S, Swanson K, Chiles SA. An evaluation of coronal microleakage in end-

odontically treated teeth. Part II: sealer types. J Endod 1987;13:109 –12.3. Krasner P, Rankow HJ. Anatomy of the pulp-chamber floor. J Endod 2004;30:5–16.4. Roghanizad N, Jones JJ. Evaluation of coronal microleakage after endodontic treat-

ment. J Endod 1996;22:471–3.5. Pisano DM, DiFiore PM, McClanahan SB, Lautenschlager EP, Duncan JL. Intraorifice

sealing of gutta-percha obturated root canals to prevent coronal microleakage. JEndod 1998;24:659 – 62.

6. Saunders WP, Saunders EM. Coronal leakage as a cause of failure in root canaltherapy: a review. Endod Dent Traumatol 1994;10:105– 8.

7. Kakehashi D, Stanley HR, Fitzgerald RJ. The effects of surgical exposures of dentalpulps in germfree and conventional laboratory rats. Oral Surg Oral Med Oral Path1965;20:340 –91.

8. Vire DE. Failures of endodontically treated teeth: classification and evaluation. JEndod 1991;17:338 – 42.

9. Balto H. An assessment of microbial coronal leakage of temporary filling materials inendodontically treated teeth. J Endod 2002;28:762– 4.

0. Schwartz RS, Fransman R. Adhesive dentistry and endodontics: materials, clinicalstrategies and procedures for restoration of access cavities: a review. J Endod2005;31:151– 65.

1. Dalat DM, Spangberg LSW. Comparison of apical leakage in root canals obturatedwith various gutta-percha techniques using a dye vacuum tracing method. J Endod1994;20:315–9.

2. Pollard BK, Weller RN, Kulild JC. A standardized technique for linear dye leakagestudies: immediate versus delayed immersion times. Int Endod J 1990;23:250 –53.

3. Shakespeare RC, Donnelly JC. An in vitro comparison of apical microleakage afterobturation with JS Quick-Fill or lateral condensation. J Endod 1997;23:312– 4.

4. Uranga A, Blum JY, Esber S, Parahy E, Prado C. A comparative study of four coronalobturation materials in endodontic treatment. J Endod 1999;25:178 – 80.

5. Davalou S, Gutmann JL, Nunn MH. Assessment of apical and coronal root canal sealsusing contemporary endodontic obturation and restorative materials and tech-niques. Int Endod J 1999;32:388 –96.

6. Wells JD, Pashley DH, Loushine J, Weller RN, Kimbrough WF, Pereira PN. Intracoro-nal sealing ability of two dental cements. J Endod 2002;28:443–7.

7. Hardy I, Liewehr FR, Joyce AP, Agee K, Pashley DH. Sealing ability of one-up bond andMTA with and without a secondary seal as furcation perforation repair materials. JEndod 2004;30:658 – 61.

8. Webber RT, del Rio CD, Brady JM, Segall RO. Sealing quality of a temporary fillingmaterial. Oral Surg Oral Med Oral Pathol 1978;46:123–30.

9. Öztan MD, Özgey E, Zaimoglu L, Erk N. The effect of various root canal sealers onIndia ink and different concentrations of methylene blue solutions. J Oral Sci2001;43:245– 8.

0. Siqueira JF, Rôças IN, Lopes HP, de Uzeda M. Coronal leakage of two root canalsealers containing calcium hydroxide after exposure to human saliva. J Endod1999;25:14 – 6.

1. Salehrabi R, Rotstein I. Endodontic treatment outcomes in a large patient populationin the USA a epidemiological study. J Endod 2004;30:846 –50.

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