|Year : 2023 | Volume
| Issue : 3 | Page : 305-310
|An in vitro evaluation of effectiveness of Xylene, Thyme oil and Orange oil in dissolving three different endodontic sealers
N Aiswarya1, TN Girish2, KC Ponnappa2
1 Department of Conservative Dentistry and Endodontics, KVG Dental College and Hospital, Sullia, Karnataka, India
2 Department of Conservative Dentistry and Endodontics, Coorg Institute of Dental Sciences, Virajpet, Karnataka, India
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|Date of Submission||20-Jan-2023|
|Date of Decision||01-Mar-2023|
|Date of Acceptance||08-Mar-2023|
|Date of Web Publication||16-May-2023|
| Abstract|| |
Aims: The aim of the study is to compare the dissolution effectiveness of xylene, thyme oil, and orange oil on three different endodontic sealers.
Materials and Methods: Standardized stainless steel molds were used to prepare 210 samples (70 for each endodontic sealer). The samples were divided into three groups based on sealers. Three experimental groups with 20 samples each were immersed in organic solvents. One control group of 10 samples was immersed in distilled water. Each group was further subdivided into two subgroups based on immersion time (2 and 10 min). Inferential statistics included one-way ANOVA, post hoc Tukey, and paired t-test.
Results: Thyme showed significantly more dissolution capacity at 10 min compared to 2 min in dissolving AH Plus sealer whereas this difference was nonsignificant for Roekoseal and MTA Fillapex. Orange oil showed significantly more dissolution at 10 min compared to 2 min in dissolving AH Plus sealer and Roekoseal whereas this difference was nonsignificant concerning MTA Fillapex. Xylene showed significantly more dissolution capacity at 10 min compared to 2 min in dissolving AH Plus sealer, Roekoseal, and MTA Fillapex.
Conclusions: Among the three solvents, xylene showed the highest dissolution of all three sealers. Orange oil was superior to thyme oil in dissolving the sealers. All the sealers showed more dissolution in all the solvents at 10 min compared to 2 min.
Keywords: Endodontic sealers; orange oil; solubility; weight loss; xylene
|How to cite this article:|
Aiswarya N, Girish T N, Ponnappa K C. An in vitro evaluation of effectiveness of Xylene, Thyme oil and Orange oil in dissolving three different endodontic sealers. J Conserv Dent 2023;26:305-10
|How to cite this URL:|
Aiswarya N, Girish T N, Ponnappa K C. An in vitro evaluation of effectiveness of Xylene, Thyme oil and Orange oil in dissolving three different endodontic sealers. J Conserv Dent [serial online] 2023 [cited 2023 Dec 8];26:305-10. Available from: https://www.jcd.org.in/text.asp?2023/26/3/305/376914
| Introduction|| |
The persistence of intra and extraradicular microbial infections is the main factor in primary endodontic therapy failure. In every failed case, nonsurgical retreatment should be chosen whenever possible over other radical therapies such as apical surgery or extraction because it is less intrusive and has a higher success rate over the long term.
The most popular core root filler material, gutta-percha, is still utilized to fill voids and canal system ramifications when combined with sealer cements. Several studies have indicated that when compared to eucalyptol, halothane, and xylol, chloroform is an effective solvent for the majority of root-filling materials. However, it has been noted that extruding chloroform into periapical tissue may be dangerous. It has been demonstrated to be possibly carcinogenic and tissue damaging.
Removal of endodontic filling material from the root canal is a requirement for retreatment. Several methods for removing the filling material – including the use of solvents, heat, and mechanical instrumentation, either alone or in combination with each other – are available. Gutta-percha, along with a variety of root canal sealers, is the most commonly used root canal filling material. It can be removed without great difficulty with the use of organic solvents or heated instruments.
Essential oils have been used in endodontics because of their proven safety, biocompatibility, and noncarcinogenicity compared to organic solvents. Therefore, selecting the right solvent requires striking a compromise between its effectiveness and usage safety.
The study was done to assess the dissolution effectiveness of xylene, thyme oil, and orange oil on silicon-based sealer, epoxy resin-based sealer, and MTA-based sealer.
| Materials and Methods|| |
Source of the data
Standardized stainless steel molds were used.
Method of collection of data
Samples prepared were examined; samples with specific dimension were included (8-mm inner diameter and 2-mm thickness).
Defective samples were excluded.
Silicon-based sealer, epoxy resin-based sealer, MTA-based sealer, xylene, thyme oil, and orange oil.
Standardized stainless steel molds (8-mm diameter and 2-mm thickness) were used to prepare 210 samples (70 for each endodontic sealer) [Figure 1].
|Figure 1: (a and b) Roekoseal samples before dissolution in solvents, (c and d) Roekoseal samples after dissolution, (e and f) AH plus sealer samples before dissolution in solvents, (g and h) AH plus sealer samples after dissolution, (i and j) MTA Fillapex samples before dissolution in solvents, (k and l) MTA Fillapex samples after dissolution|
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The samples were divided into three groups based on sealers: 70 for silicon-based sealer, 70 for epoxy resin-based sealers, and 70 for MTA-based sealers. Three experimental groups with 20 samples each were immersed in organic solvents. One control group of 10 samples was immersed in distilled water. Each group was further subdivided into two subgroups based on immersion time (2 and 10 min) [Table 1].
Each sealer was mixed according to manufacturer's instructions. Freshly mixed materials were carefully poured into sample molds placed on a glass slab using a 2 ml syringe to prevent air entrapment, and a microscope slide covered with cellophane strip was then pressed into the upper surface to make the surface flat. All the samples along with the steel molds were transferred to a chamber with 80% relative humidity and 37°C temperature and left untouched for sealers to set for 48 h and were removed from the chamber. Excess material was then removed with the help of scalpel. The samples were weighed in grams 3 times on an analytical balance. The mean values were then calculated.
At room temperature, all sealer samples were immersed completely in 20 ml of solvent stored in glass vials. After the specified immersion period (2 min and 10 min), the samples were removed from glass vials, rinsed with 100 ml of triple distilled water, and then blot dried with absorbent paper. Samples were allowed to dry for 24 h at 37°C ± 1°C in an oven and then kept in desiccators. Thereafter, the samples were weighed 3 times and the mean was calculated. The amount of sealer dissolved was determined as the difference between the original weight of the sealer and its final weight.
| Results|| |
Thyme showed significantly more dissolution capacity at 10 min compared to 2 min in dissolving AH Plus sealer (P = 0.028) whereas this difference was nonsignificant with respect to Roekoseal (P = 0.990) and MTA Fillapex (P = 0.712).
Orange oil showed significantly more dissolution at 10 min compared to 2 min in dissolving AH Plus sealer (P = 0.022) and Roekoseal (P = 0.004) whereas this difference was nonsignificant with respect to MTA Fillapex (P = 0.213). The above findings are shown in [Graph 1], [Graph 2], [Graph 3].
Xylene showed significantly more dissolution capacity at 10 min compared to 2 min in dissolving AH Plus sealer (P = 0.013), Roekoseal (P = 0.001), and MTA Fillapex (P = 0.001).
| Discussion|| |
For management of endodontic failures, the preferred line of treatment is nonsurgical endodontic therapy. To disclose remnants of necrotic tissue or bacteria that may be responsible for periapical inflammation and failure, removal of sealer and gutta-percha as much as possible from insufficiently prepared and obturated root canal systems is necessary.
Shin et al. recommended retrieving resin-based root canal sealer using the Gates Glidden and Profile systems. Many strategies for removing root filling materials were recommended by Duncan and Chong, including the use of hand files, rotary files, ultrasonic, heated pluggers, and solvents.,
Chloroform and eucalyptol have been used as solvents since 1850. Chloroform, although an excellent solvent, is highly toxic and has carcinogenic potential; its clinical use has been prohibited in humans since 1976. Studies confirm that substances when placed in the tooth pulp chamber, have access to periapical tissue and the circulatory system.,
Due to their demonstrated safety, biocompatibility, and noncarcinogenicity, essential oils are being employed more and more in endodontics. Orange oil, eucalyptol, and clove oil have been investigated since early 1990s for their GP dissolving ability. Endodontic literature regarding the dissolution of conventional GP has been inconsistent with some reports suggesting orange oil to be a superior solvent than eucalyptol, whereas others showing no difference between them.
Essential oil extracted from the peel of sweet orange, citrus aurantium, is easy to obtain. When used on zinc-oxide eugenol cement or to soften and to dissolve gutta-percha, orange oil is a suitable alternative to potentially harmful solvents. D-Limonene (refined orange oil) is a primary ingredient of many essential oils and is found widely in citrus and other plant species.
Various essential oils, namely anise oil, eucalyptol, eugenol, castor oil, cottonseed oil, lavender oil, orange oil, peppermint oil, pine needle oil, thyme oil, and oil of white pine, have been evaluated for their ability to dissolve gutta-percha.
Thymus is a genus of about 215 species that thrive in hot and dry regions. Thymus vulgaris is a plant native to southern Europe that is grown for its antibacterial, antifungal, and anti-inflammatory properties. The major constituents of commercial T. vulgaris are thymol (23%–60%), terpinene (18%–50%), P-cymene (8%–44%), carvacrol (2%–8%), and linalool (3%–4%).
The chlorinated hydrocarbon xylene is commonly used as a gutta-percha solvent. It could also soften the sealers, making them easier to remove mechanically. Chloroform is messy and inconvenient because it dissolves rather than softens the gutta-percha, leaving residues on the pulp chamber walls. Its rapid evaporation necessitates the addition of more and more solvent as it evaporates. In contrast, xylene dissolves gutta-percha more slowly, providing for better control and disposal of softened rather than liquefied gutta-percha.
The sealers employed in this study were as follows: AH Plus is an epoxy-amine resin-based sealer that comes in a two pastes. It has a short working time and is simple to mix, allowing for precise adaptation to the prepared root canal and resists shrinkage after setting, as well as providing excellent long-term structural stability.
Roekoseal is a root canal sealer made of polydimethylsiloxane. It expands by 0.2% over the first 4 weeks and then stays steady, improving its sealing ability without creating excessive forces within the root canal.,,,
MTA Fillapex contains MTA, salicylate resin, natural resin, bismuth, and silica as the main ingredients, according to the manufacturer. MTA Fillapex is the first MTA-based salicylate resin root canal sealer that can be used with any obturation procedure.
In the present study, the effectiveness of xylene, orange oil, and thyme oil was evaluated on three different endodontic sealers. In all the solvent groups, all three sealers showed more weight loss at 10 min than 2 min. In the control group (distilled water), minimum and insignificant (P > 0.05) weight loss were observed for all sealers at both time periods.
In Roekoseal (Group I) P < 0.05, there was a significant difference in the loss of weight in the xylene and orange oil groups between 2 min and 10 min [Table 2].
The effectiveness of xylene was superior to all the other solvents. Orange oil was inferior to xylene but superior to thyme oil and distilled water. Dissolution at 10-min time interval was more compared to 2 min; however, this was statistically significant in xylene and orange oil [Table 3].
|Table 3: Mean weight loss of AH plus sealer with different solvents (Group II)|
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In AH Plus sealer (Group II), weight loss of sealer in 2 min and 10 min was compared. Since the resulting P < 0.05, this study reports a significant difference in the mean weight loss between the solvent. The effectiveness of xylene was superior to all the other solvents. Orange oil was inferior to xylene but superior to thyme oil and distilled water.
Dissolution at 10-min time interval was more compared to 2 min in all the solvents.
Magalhães et al. evaluated the solubility of gutta-percha in four solvents: xylene, orange oil, eucalyptol, and chloroform. Xylene presented the best solvent capacity. Chloroform, orange oil, and eucalyptol performed similarly [Table 4].
|Table 4: Mean weight loss of MTA Fillapex in different solvent material (Group III)|
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In MTA Fillapex (Group III) P < 0.05, there was a significant difference in the loss of weight in xylene group between 2 and 10 min. The effectiveness of xylene was superior to all the other solvents. Orange oil was inferior to xylene but superior to thyme oil and distilled water. Dissolution at 10-min time interval was more compared to 2 min; however, this was statistically significant in xylene.
Maximum dissolution capacity of xylene in the present study is in supportive of studies conducted by Kaplowitz. The present study is similar to the findings by Martos et al. who stated that dissolving capacity of orange oil is inferior to chloroform and xylene at 2 min and 10 min also added that orange oil and thyme oil have been shown to be more biocompatible than turpentine, xylene, chloroform, and halothane.
In the present study, dissolving capacity of thyme oil was highest at 10 min. Because essential oils and other organic solvents have different solvent capacities, thyme oil and orange oil were used to dissolve endodontic sealers. The selection of an optimal solvent necessitates striking a balance between clinical safety, tissue toxicity, and dissolving chemical capacity.
Xylene causes irritation of eyes and mucous membranes, cytotoxic reaction when extruded periapically. However, Chutich et al. have suggested that the amount of xylene periapically extruded was too small to cause toxicity.
Differences in dissolving efficiency were also reported by Wennberg and Orstavik who compared several solvents in search of alternatives to chloroform for dissolving gutta-percha.
A study conducted by Oyama et al. showed better softening action of orange oil when compared with eucalyptol.
The current investigation did not take into account therapeutically imposed criteria such as canal system anatomy or temperature when it came to the effect of solvents on root canal sealing cement. As a result, its findings cannot be directly applied to clinical circumstances.
Further, in vivo and in vitro studies with more variables are necessary to support the effectiveness of various essential oils for dissolution of endodontic sealers.
| Conclusions|| |
Within the limitations of this in vitro investigation, it can be concluded that:
- Among the three solvents, xylene showed highest dissolution of all the three sealers
- Orange oil was superior to thyme oil in dissolving the sealers
- Thyme showed significantly more dissolution capacity at 10 min compared to 2 min in dissolving AH Plus sealer (P = 0.028) whereas this difference was nonsignificant with respect to Roekoseal (P = 0.990) and MTA Fillapex (P = 0.712)
- Orange oil showed significantly more dissolution at 10 min compared to 2 min in dissolving AH Plus sealer (P = 0.022) and Roekoseal (P = 0.004) whereas this difference was nonsignificant with respect to MTA Fillapex (P = 0.213)
- Xylene showed significantly more dissolution capacity at 10 min compared to 2 min in dissolving AH Plus sealer (P = 0.013), Roekoseal (P = 0.001), and MTA Fillapex (P = 0.001)
- All the sealers showed more dissolution in all the solvents at 10 min compared to 2 min. However, this change was not significant for Roekoseal, MTA Fillapex in thyme oil, and MTA Fillapex in orange oil
- In distilled water, no sealer dissolution was observed (P > 0.05).
Financial support and sponsorship
Conflicts of interest
There are no conflicts of interest.
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Dr. N Aiswarya
Department of Conservative Dentistry and Endodontics, KVG Dental College and Hospital, Sullia, Karnataka
Source of Support: None, Conflict of Interest: None
[Table 1], [Table 2], [Table 3], [Table 4]
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