|Year : 2016 | Volume
| Issue : 1 | Page : 1-5
Comparative evaluation of fracture resistance of teeth obturated using three different systems – AH plus/Gutta-percha, Resilon/Realseal self-etch, and Endofill/Gutta-percha: An in vitro study
G Ratna Velugu1, P Karunakar2, MS Ranga Reddy2
1 Department of Conservative Dentistry and Endodontics, School of Dental Sciences, Sharda University, Noida, Uttar Pradesh, India
2 Department of Conservative Dentistry and Endodontics, Panineeya Mahavidyalaya Institute of Dental Sciences and Research Center, Hyderabad, Telangana, India
|Date of Web Publication||16-May-2016|
G Ratna Velugu
Room No. 306, School of Dental Sciences, Sharda University, Knowledge Park III, Greater Noida - 201 306, Uttar Pradesh
Source of Support: None, Conflict of Interest: None
Introduction: Endodontically treated teeth are more prone to fracture under masticatory forces. Resin-based dental materials have been proposed as a means to reinforce an endodontically treated tooth through the use of adhesive sealers in the root canal system.
Aims: The objective of this study is to evaluate the fracture resistance of endodontically treated teeth obturated using lateral compaction technique with AH plus/Gutta-percha, Resilon/RealSeal self-etch (SE), and Endofill/Gutta-percha.
Subjects and Methods: In this study, sixty, single-rooted mandibular premolars were used. The teeth chosen were de-coronated with a diamond disc and the root length was 14 mm for each specimen. All teeth were enlarged up to ISO size 30 master apical file using Ni–Ti rotary Protaper system and crown-down technique. Instrumented teeth were then randomly assigned into four experimental groups (n = 15) as follows: Group 1 - obturated with AH plus/Gutta-percha, Group 2 - obturated with Resilon/RealSeal SE, Group 3 - obturated with Endofill/Gutta-percha, and Group 4 - no obturation was done (control). The specimens were embedded into auto-polymerizing resin, later mounted in the universal testing machine and were subjected to load at a crosshead speed of 1.0 mm/min until the root fractured.
Statistical Analysis Used: ANOVA and Duncan post hoc analysis.
Results: Results of this in vitro study showed that Resilon/RealSeal SE showed better fracture resistance of all the materials tested. Statistically significant difference between the groups (<0.001) was observed.
Conclusions: Resilon/RealSeal SE demonstrated higher fracture resistance values than AH plus/Gutta-percha, followed by Endofill/Gutta-percha
Keywords: AH plus, Endofill, fracture resistance, Gutta-percha, Resilon, Resilon/RealSeal self-etch
|How to cite this article:|
Velugu G R, Karunakar P, Ranga Reddy M S. Comparative evaluation of fracture resistance of teeth obturated using three different systems – AH plus/Gutta-percha, Resilon/Realseal self-etch, and Endofill/Gutta-percha: An in vitro study. J Oral Res Rev 2016;8:1-5
|How to cite this URL:|
Velugu G R, Karunakar P, Ranga Reddy M S. Comparative evaluation of fracture resistance of teeth obturated using three different systems – AH plus/Gutta-percha, Resilon/Realseal self-etch, and Endofill/Gutta-percha: An in vitro study. J Oral Res Rev [serial online] 2016 [cited 2022 Jan 20];8:1-5. Available from: https://www.jorr.org/text.asp?2016/8/1/1/182485
| Introduction|| |
Obturation not only marks the end point of the endodontic treatment sequence, but also the harbinger of holistic healing of peri-apical tissues and influences the fracture resistance of tooth structure. Teeth treated endodontically are more susceptible to fracture because of brittleness of dentin caused by collapse of the collagen architecture, extensive restorations, and a reduced amount of tooth structure.,,, Different endodontic-filling materials and technologies have been introduced to improve the fracture resistance of endodontically treated tooth., The sealers used had shortcomings in that a fluid-tight seal along the dentinal walls was not routinely achieved and the adhesive strength between endodontic sealers, dentin, and Gutta-percha was shown to be very weak.,, Strengthening of endodontically treated teeth has been proposed by establishing monoblocks via bonding of the root filling materials to intraradicular dentin.,,
The purpose of thisin vitro study was to investigate the fracture resistance of root canal treated teeth obturated with Resilon/RealSeal self-etch (SE), AH plus and Gutta-percha, and Endofill and Gutta-percha system.
| Subjects and Methods|| |
In thisin vitro experimental study, sixty intact caries-free human single-rooted teeth with straight roots and mature apices were selected. The teeth were autoclaved and kept in 0.5% sodium hypochlorite (Merck, Germany) overnight. Crowns were removed using a bi-sided diamond disc to achieve an average of 14 mm root length. Then, patency of each canal was confirmed by inserting a size 15-K file (Mani, Japan) through the apical foramen, and the working length was established by subtracting 1 mm from this measurement. Root canals were rinsed with 5.25% sodium hypochlorite (Merck, Germany). All the root canals were instrumented to an apical size F3 (corresponding to ISO #30) with rotary ProTaper system (Dentsply Maillefer) using crown-down technique. The root canals were irrigated with 2 ml of 5.25% NaOCl between each instrument used. After preparation, the root canals were irrigated with 5 ml of 17% ethylene diaminetetraacetic acid (EDTA: Merck, Germany) and 5 ml of 5.25% NaOCl to remove the smear layer, followed by a final flush of distilled water for total removal of NaOCl. The canals were dried with paper points. The teeth were randomly allocated into four groups containing 15 teeth each. Group 1 - lateral condensation with AH plus/Gutta-percha, Group 2 - lateral condensation with Resilon/RealSeal SE, Group 3 - lateral condensation with Endofill/Gutta-percha, and Group 4 - no obturation was done (control). In case of root filling by lateral condensation using Resilon points and RealSeal SE (SybronEndo), the RealSeal SE primer was applied by using a microbrush in the canal, and excess was removed by using paper points. Lateral compaction was done; material in the root canal was light cured for 40 s with a LED (IvoclarVivadent). In Groups 1, 2, and 3, excess material was seared off and condensed with pluggers, and the access openings were sealed with Cavit G (3M ESPE).
Storage of samples
The root canal fillings were checked for their obturation quality using RadioVisioGraphy. All samples were stored at 37°C in 100% humidity for 1 week to simulatein vivo conditions ensuring correct setting of sealing material.
Preparation for mechanical testing
All the roots were mounted vertically in self-cure acrylic resin (DPI-RR, Mumbai, India) blocks exposing 8 mm of the coronal part. These acrylic blocks were mounted in a universal testing machine (Auto Graph AG IS, Shimadzu, Japan). A steel spherical tip with a diameter of 5 mm was placed on the universal testing machine fixture and placed directly above the root canal orifice. The blocks were mounted with the vertically aligned roots in the testing machine one at a time. Each specimen was subjected to load at a crosshead speed of 1 mm/min until the root fractured. The test was terminated at this point and the force required to fracture the roots was recorded in Newton. Fracture was defined as the point at which a sharp and instantaneous drop of the applied force was observed. The amount of force required for fracture was recorded for each root. For most specimens, an audible crack was also heard. Throughout the test, the roots were kept fully hydrated. The force applied to the root canal via the tip was recorded in the form of a graph.
| Results|| |
The tables reveal the mean and standard deviation of different test groups; there was a significant difference in the fracture resistance among the materials tested by ANOVA (P< 0.001). Group 2 showed the maximum fracture resistance and Group 4 showed the minimum fracture resistance [Table 1], [Table 2], [Table 3].
|Table 1: Maximum load required to fracture specimens of different groups (fracture resistance in Newtons) n= 15 in each group|
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|Table 2: Mean and standard deviation of (Maximum) load required to fracture specimens of different groups (fracture resistance in Newtons) n= 15 in each group|
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Post hoc test reveals that there was a significant difference in all the materials tested with Group 4 (Control) being the lowest and Group 2 (Resilon/RealSeal SE) being the highest.
Group 2 >Group 1 >Group 3 >Group 4.
| Discussion|| |
Obturation in root canal treatment plays an important role in providing the coronal and apical seal and acts as a foundation for the postendodontic restoration. Endodontically treated teeth are more susceptible to fracture than those with intact pulp. Vertical fracture of such teeth is a major cause of failure and may eventually lead to extraction. The clinical concept of “brittle” or weakened endodontically treated teeth has been attributed to the loss of tooth structure following trauma, caries, endodontic access, instrumentation and irrigation procedures, and/or to changes in the properties of teeth following endodontic treatment.,
Endodontically treated teeth have significantly different physical and mechanical properties when compared to vital teeth. Fractures in endodontically treated teeth have been understood to be multifactorial in origin. The causes of fracture in endodontically treated teeth can be broadly classified as iatrogenic and noniatrogenic. Iatrogenic causes being tooth structural loss, effect of chemicals and intracanal medicament, and effects of restorative procedures and restorations. Noniatrogenic causes can be a history of recurrent pathology, anatomical position of the tooth, and the effect of aging of dental tissues.
Different materials have been used as root canal filling material. Zinc-oxide eugenol (ZOE) based sealers were introduced by Grossman in 1936 to be used in conjunction with Gutta-percha or silver coins. Endofill is a commonly used ZOE-based sealer, available in powder-liquid form.
Gutta-percha has been widely used as a root canal filling material and serves as a gold standard for comparing other materials. The sealer plays an important role in the obturation of the root canal. The sealer fills up all the spaces that the Gutta-percha is unable to fill. The sealer acts as a binding agent to the dentin and to the Gutta-percha. One of the major limitations with the obturating materials was the improper adaptation of sealer to canal wall and Gutta-percha. This led to the introduction of bonding obturating materials. Glass ionomer-based sealer, (Ketac-Endo Aplicap) and dentin bonding agents were extensively used and investigated for their potential to reinforce the weakened endodontically treated teeth.,
The success of resin materials in restorative dentistry has resulted in the acceptance of the use of polymer-based sealers for the treatment of endodontically treated teeth. These materials have been introduced as root canal sealers to penetrate dentinal tubule, bond to the collagen matrix, and subsequently, imparting adhesive strength to dentin.
Recently, resin-percha (Resilon) and resin-coated Gutta-percha (EndoRez) have become available with the resin sealers. This increases the fracture resistance of the root-filled teeth by forming “Monoblock,” i.e., the core material binds to sealer, which in turn binds to the root dentin, forming a single unit.
In this study, Gutta-percha with AH plus sealer; Resilon with RealSeal SE sealer, and Endofill with Gutta-percha were used for obturating the tooth sample using lateral compaction technique.
AH plus is a two-component root canal sealer based on epoxy-amine resin chemistry and is marketed by Dentsply, available as two-paste system.
Endofill (Dentsply/Maillefer, Tulsa, OK, USA) is a ZOE-based cement which has desirable physicochemical properties, and is one of the most commonly used sealers in daily clinical practice. Thus, this sealer was taken as a standard against which other sealers were compared in this study. It is available in powder and liquid form. Powder consists of zinc oxide, resin (staybelite), bismuth subcarbonate, barium sulfate, borax, and the liquid is composed of eugenol and peanut oil.
Resilon was introduced by Dr. Martin Thorpe and Dr. Ray and was approved at the annual session of ADA in 2003.,, The Resilon obturation SE system consists of two parts: RealSeal SE – it is a dual-curing, resin-based composite sealer. It consists of BisGMA, ethoxylated BisGMA, HEMA, acidic methacrylate resins, silane-treated barium-borosilicate glasses, aluminum oxide silica, hydroxyapatite, Ca-Al-F-silicate, bismuth oxychloride with amines, peroxide, photo initiator, stabilizers, and pigment. The total filler content is approximately 70% by weight.,,
Resilon core material: It contains polycaprolactone and dimethacrylate resin that are blended to form a filled thermoplastic composite material. It also contains bioactive glass, bismuth oxychloride, and barium sulfate as fillers. The filler's content is approximately 65% by weight.,,
Resilon has an appearance similar to that of Gutta-percha and is therefore called resin-percha. It is available in standardized points that match endodontic instruments and in various tapers, and also as accessory points and pellets for use with the Obtura II delivery system.,, The placement of the Resilon obturation system involves the removal of the smear layer with EDTA, drying the canal with the paper points followed by placement of sealer SE using paper points. Excess primer is wicked out of the canal using paper points. This is followed by placement of the sealer, and finally, Resilon obturation with the method of choice. Light curing for 40 s provides an immediate coronal seal. If not light-cured, the material sets within 1 h.
Resilon obturating material prevents the microleakage by a factor of 6 times and strengthens the root. There is a reported 22% increased resistance to root fracture. The hybrid layer was observed both by transmission electron microscopy and confocal microscopy and is order of 1–2 μm. The other advantages of the Resilon includes – better radiopacity than Gutta-percha, dual cure capabilities for immediate coronal seal  and better biocompatibility,, it can be removed using conventional techniques.
In this study, the Resilon groups were significantly more resistant to fracture than were the Gutta-percha groups, indicating that the monoblock concept is important to hold the root together, thereby increasing the resistance to fracture. In addition, AH plus showed better result than Endofill, this can be attributed to AH plus sealer's inherent property of volumetric expansion (4–5%), which contributes to better bond strength. The sealer penetrates the tubules after final irrigation with EDTA and this has been shown to increase the fracture resistance of endodontically treated teeth.,,
The results of this study were comparable with the study conducted by Teixeira et al. who tested Resilon and AH plus/Gutta-percha for fracture resistance. Their study concluded that Resilon exhibited greater mean fracture resistance than the other groups. They also tested the lateral and vertical compaction technique for each material, but did not find any significant difference between these two techniques on fracture resistance. Another study by Hammad et al. assessed the fracture resistance of endodontically treated teeth obturated with zinc-oxide/Gutta-percha; Resilon, EndoRez, and Guttaflow. The study concluded that both the Resilon and EndoRez obturating material exhibited better fracture resistance than the other group.
Few researchers have compared the fracture resistance of the root-filled teeth with Resilon, AH 26/Gutta-percha, and MCS canal sealer/Gutta-percha. They did not find any significant difference between these obturating materials in reinforcing root-filled teeth and all were equal in reinforcing the prepared root canals.
Edgar Schafer and others studied the influence of Resilon and AH plus/Gutta-percha in reinforcing the endodontic-treated roots. The intact roots were inherently stronger than the other groups, which are consistent with this study. The roots obturated with RealSeal were significantly stronger than those obturated with Gutta-percha and AH plus. Within the limitations of this study, it can be inferred that the Resilon/epiphany obturating system reinforces the root-filled teeth more than the AH plus/Gutta-percha and Endofill/Gutta-percha.
| Conclusion|| |
On the basis of this study, it can be concluded that Resilon demonstrated higher fracture resistance than the other materials and it may be an alternative obturating material to the conventional Gutta-percha in the near future. However, further studies are required to evaluate the fracture resistance of endodontically treated teeth obturated with the new resin materials.
Financial support and sponsorship
Conflicts of interest
There are no conflicts of interest.
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[Table 1], [Table 2], [Table 3]