Dissolution of root canal sealer cements in volatile solvents

Impact of Solvent Properties of Cold-Pressed and Steam-Distilled Orange Oils on GuttaFlow2 and Gutta-Percha

INTRODUCTION

Root canal retreatment often employs organic solvents like chloroform, eucalyptol, and orange oil. However, studies comparing their effectiveness yield inconsistent results. The quantity of d-limonene, a crucial component in orange oil, varies depending on the oil production method. Cold-pressed orange oil has been observed to contain the highest d-limonene levels. This study investigates the comparative solvent effects of cold-pressed and steam-hydrodistilled orange oils on gutta-percha and GuttaFlow2, typically used components in root canal fillings.

METHODS

Thirty-two discs (10 mm in diameter and 2 mm in thickness) were prepared using GuttaFlow and gutta-percha cones. The samples were weighed and then randomly divided into four groups (n=8) based on the type of solvent used. Each group was immersed in its respective solvent for 10 minutes. After exposure to the solvent, the samples were reweighed to determine the amount of material removed.

RESULTS

The weight loss in the group treated with cold-pressed orange oil on gutta-percha was significantly higher than in other groups (GuttaFlow2 + cold-pressed orange oil, gutta-percha + steam hydrodistilled orange oil, GuttaFlow2 + steam hydrodistilled orange oil) (p<0.001, p<0.001, and p<0.001).

CONCLUSION

According to the study findings, cold-pressed orange oil demonstrated a higher solvent effect on both GuttaFlow2 and traditional gutta-percha compared to steam-hydrodistilled orange oil. This indicates the significant impact of the production method of orange oil on its efficacy as a solvent in root canal therapy retreatment.

Comparing the softening effect of three gutta-percha solvents on different types of gutta-percha with different application durations

Introduction

During non-surgical endodontic retreatment, gutta-percha (GP) solvents are indispensable in difficult cases when used with mechanical removal, however studies comparing their efficacy against different types of GP are limited. The purpose of this study was to investigate the softening effect of three solvents on the conventional (CGP), cross-linked carrier-based (CLGP), and thermoplasticized (TGP) and compare the effect of time on the softening effect of the solvents.

Methods

Tested GP were embedded in cuboidal blocks of stone with their upper surfaces exposed (1 mm diameter). Three commercial GP solvents based on D-Limonene (DL), Eucalyptol oil (EO), and orange oil (OO) were added to the exposed GP before an indenter (weight = 1Kg) was applied. Using a digital camera, the indentation depth was measured (mm) directly after applying the solvent and indenter (T = 0), and after 1, 2, and 3 min of application (T = 1,2,3). The means of indentation depth were calculated and compared using a two-way analysis of variance and Tukey's post-hoc test to assess the effect of the types of solvent, GP for each application duration, and Friedman's test to evaluate the effect of application duration on the softening effect of solvents.

Results

The type of GP (F = 261.43, p < 0.001), type of solvent (F = 3.57, p = 0.015), and application duration (F = 53.088, p < 0.001) were all found to significantly affect GP softening. DL exhibited the highest and only significant effect on CGP after 1 min (p < 0.05), while OO had the only significant effect against CLGP when applied for at least 2 min (p < 0.05). Both OO and EO had significant softening effects on TGP instantly or after 1 min of application, respectively.

Conclusions

The results of this study revealed that the softening effect of GP solvents varies depending on their type, their application duration, and the type of GP.

An in vitro evaluation of effectiveness of Xylene, Thyme oil and Orange oil in dissolving three different endodontic sealers

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.

The Novel Role of Solvents in Non-Surgical Endodontic Retreatment

Non-surgical endodontic retreatment is a reliable conservative option for managing post-treatment apical periodontitis. However, effective microbial control, based on the maximization of filling removal and disinfection protocols, is not yet predictable. Traditional gutta-percha solvents, which are indistinctively used for both the core and sealer filling materials, became obsolete due to unprecedented advances in endodontic technology. Nonetheless, microtomography, scanning electronic microscopy findings, and histobacteriological analysis tend to confirm the persistence of filling materials and the lack of association between root canal enlargement and superior disinfection. There is a controversy regarding the most suitable clinical protocols surrounding the shaping procedures and the supplementary disinfection steps. Based on the literature and the previous work of the team, the authors aimed to summarize the current knowledge regarding specific solvent formulations that target filling materials. Additionally, the advantage of an additional irrigation step to optimize disinfection was highlighted. This adjunctive procedure serves a dual role in the dissolution of filling materials, and in conferring an antibiofilm effect. Further research is needed to understand the novel contribution of these strategies upon clinical practice outcomes.

Evaluation of Antibacterial Properties of Organic Gutta-percha Solvents and Synthetic Solvents Against Enterococcus faecalis

Background:

The use of solvents is necessary to remove remnants of filling materials within dentinal tubules to allow penetration of irrigating solution within the tubules.

Aim and Objectives:

We aimed at determining the antibacterial effect of various gutta-percha (GP) solvents against Enterococcus faecalis (E. faecalis).

Materials and Methods:

An in vitro study was conducted by measuring the zone of inhibition using the disk diffusion method. The test organism used for the study was E. faecalis, and the solvents were divided into five groups: eucalyptus oil, chloroform, turpentine oil, xylene, and orange oil. About 500 μL of the suspension was spread over the agar plates, and the empty sterilized disks were impregnated with 10 μL of pure essential oils (EOs). The inoculated plates were incubated at 37°C for 18 to 24 h. The antimicrobial activity of each solvent was expressed and measured in terms of the mean diameter of the zone of inhibition (in mm) produced by each solvent at the end of the incubation period. ANOVA was used for intergroup comparison. The P-value of <0.05 was considered significant.

Results:

The mean zone of inhibition for E. faecalis was 24.00 ± 1.21 for eucalyptus oil, 16.30 ± 0.92 for chloroform, 26.50 ± 1.24 for turpentine oil, 13.70 ± 1.26 for xylene, and 19.80 ± 1.32 for orange oil. The difference between the groups was statistically significant (P < 0.001).

Conclusion:

This study demonstrated that the use of turpentine oil during endodontic retreatment significantly reduced the levels of E. faecalis as compared with other solvents.

The effectiveness of eucalyptus oil, orange oil, and xylene in dissolving different endodontic sealers

Objective:

The objective of this study was to evaluate the dissolution effectiveness of eucalyptus oil, orange oil, xylene, and distilled water on three different endodontic sealers.

Materials and Methods:

About 240 samples of root canal sealers (eighty for each sealer) were prepared and divided into four groups of 20 each for immersion in different organic solvents. Each group was further subdivided into two subgroups (n = 10) for 2 and 10 min of immersion time. The mean percentage of weight loss was determined for each sealer in each solvent at both time periods. Data were statistically analyzed by two factor analysis of variance and significance of mean difference was obtained by Tukey's post hoc test (P < 0.05).

Results:

The lowest level of solubility was observed for Adseal followed by Apexit Plus and Endomethasone N at both time periods in all solvents. Apexit Plus showed no significant (P > 0.05) difference in its dissolution in all the organic solvents except distilled water at both the time periods. The solubility profile of Endomethasone N and Adseal did not differ significantly among eucalyptus oil, orange oil, and xylene at 2 min and between eucalyptus oil and orange oil at 10 min. However, at 10 min, Endomethasone N and Adseal showed a more pronounced solubility in xylene as compared to both eucalyptus oil and orange oil.

Conclusions:

In general, xylene was the most effective in dissolving root canal sealers than other organic solvents. Essential oils (eucalyptus oil and orange oil) were found similar in their ability to dissolve Apexit Plus and Endomethasone N.

Solubility evaluation of different root canal sealing materials

AIM

To evaluate the solubility of five different root canal sealers (AH Plus Jet, RealSeal SE, MTA Fillapex, Tubli-Seal, and Acroseal) in chloroform, eucalyptol and Endosolv-E solvents.

MATERIALS AND METHODS

Ninety root canal sealer samples were prepared and then divided into three groups for immersion in a solvent for 2, 5 or 10 minutes. The mean values of the root canal sealers' dissolution in the solvents were obtained by the difference between the preimmersion original weight and the post-immersion weight on a digital analytical scale. Data were statistically analyzed by a Kruskal-Wallis test with a Bonferroni correction.

RESULTS

Chloroform was a more effective solvent than eucaly-ptol or Endosolv E for all root canal sealers, except for RealSeal SE, at all time points (p < 0.003). RealSeal SE was the least soluble sealer in all solvents at all time points.

CONCLUSION

Chloroform demonstrated a superior ability over other solvents in dissolving canal sealing materials, and eucaly-ptol was found to be the least effective solvent in this study.

CLINICAL SIGNIFICANCE

This study can help to the clinicians about which solvent should be preferred for solving the filling materials in retreatment cases.

The effect of different organic solvents on the degradation of restorative materials

Objective:

To evaluate the solubility of three restorative materials exposed to the different endodontic solvents.

Materials and Methods:

The organic solvents eucalyptus oil, xylol, chloroform, and orange oil, with distilled water as the control group was utilized. The restorative materials light-cured resin (Filtek Z250/3M ESPE), light-cured-resin-reinforced glass ionomer (Riva Light Cure LC/Southern Dental Industries SDI]) and resin-modified glass ionomer (Vitremer/3M ESPE) were analyzed. A total of 50 disks containing specimens (2 mm × 8 mm Ø) were prepared for each of the three classes of restorative materials, which were divided into 10 groups (n = 5) for immersion in eucalyptus oil, xylol, chloroform, orange oil or distilled water for periods of either 2 min or 10 min. The means of restorative material disintegration in solvents were obtained by the difference between the original preimmersion weight and the postimmersion weight in a digital analytical scale. Data were statistically analyzed by two-way analysis of variance while the difference between the materials was analyzed by Student-Newman-Keuls test. The significance level set at 0.05.

Results:

Vitremer showed the highest solubility, followed by Riva LC, and these were statistically different from eucalyptus oil, xylol, chloroform, and distilled water (P < 0.05). Regarding the immersion time in solvents, there were no significant differences between the two tested periods (P > 0.05).

Conclusions:

The solvents minimally degraded the composite resin, although they did influence the degradation of both resin-modified glass ionomer resin and resin reinforced with glass ionomer.

The effect of four different irrigation systems in the removal of a root canal sealer

OBJECTIVES

The aim of this study was to compare the efficiency of sonic, ultrasonic, and hydrodynamic devices in the removal of a root canal sealer from the surface and from simulated irregularities of root canals.

MATERIALS AND METHODS

Fifty-three root canals with two standardized grooves in the apical and coronal parts of longitudinally split roots were covered with AH Plus root canal sealer. Compared were the effects of (control) syringe irrigation, (1) CanalBrush, (2) passive ultrasonic irrigation, (3) EndoActivator, and (4) RinsEndo on the removal of the sealer. The specimens were divided into four groups (N = 12) and one control group (N = 5) via randomization. The amount of remaining sealer in the root canal irregularities was evaluated under a microscope using a 4-grade scoring system, whereas the remaining sealer on the root canal surface was evaluated with a 7-grade scoring system.

RESULTS

Passive ultrasonic irrigation is more effective than the other tested irrigation systems or syringe irrigation in removing sealer from root canal walls (p < 0.01). None of the techniques had a significant effect on cleaning the lateral grooves.

CONCLUSIONS

Within the limitations of this study protocol ultrasonic irrigation shows a superior effect on sealer removal from the root canal surface during endodontic retreatment. Cleaning of lateral grooves seems not to be possible with one of the techniques investigated.

CLINICAL RELEVANCE

Incomplete removal of root canal sealer during re-treatment may cause treatment failure. Passive Ultrasonic irrigation seems to be the most effective system to remove sealer from a root canal.

Influence of different organic solvents on degree of swelling of poly (dimethyl siloxane)-based sealer

The study evaluated the compatibility of chloroform, ether, and xylene with poly(dimethyl siloxane) (PDMS) based sealer. Freshly mixed sealer was placed in 90 glass molds with 5 mm diameter and 2 mm thickness. All samples were stored in 75% relative humidity at 37°C for 2 weeks. All the samples were divided into three groups: group A - chloroform; group B - ether, and group C - xylene and immersed in fresh solvent at room temperature. The specimens were weighed before and after immersion for each group at the end of 2, 5, and 10 min. The swelling ratio was calculated for all the groups. Intergroup comparison revealed no difference in the mean swelling ratio for 2, 5, and 10 min (P > 0.001; Tukey HSD Post Hoc). Intragroup comparison revealed significant difference in swelling ratio between 2 and 5 min for group B and group C (P < 0.001; Paired t test). Ether has the highest compatibility with PDMS-based sealer after 2 min followed by xylene after 5 min.

Dissolving efficacy of eucalyptus and orange oil, xylol and chloroform solvents on different root canal sealers

AIM

To evaluate the solubility of five root canal sealers in orange oil, eucalyptol, xylol and chloroform solvents.

METHODOLOGY

The solubility of RoekoSeal, Sealer 26, Epiphany, Endomethasone and EZ-Fill sealers was assessed in orange oil, eucalyptol, xylol, chloroform and distilled water. Seventy-five samples of root canal sealers were prepared and then divided into five groups for immersion in solvent for 2, 5 or 10 min. The means of loss weight were determined for each material in each solvent at all immersion periods, and the values were compared by factorial analysis of variance (anova) and SNK multiple comparisons.

RESULTS

In the orange and eucalyptus oil groups, there was no significant difference among RoekoSeal, Sealer26, Epiphany and EZ-Fill at the three immersion periods (P > 0.05). With xylol, no significant differences were found at 5 and 10 min (P > 0.05) for each root sealer. Orange and eucalyptus oil solvents were as effective as chloroform at 2 min in dissolving all the root sealers.

CONCLUSIONS

Xylol was the most effective solvent followed by the chloroform and the essential oils (eucalyptol and orange oil). Orange oil behaved in a similar way to eucalyptus oil.

Properties and applications of calcium hydroxide in endodontics and dental traumatology

Calcium hydroxide has been included within several materials and antimicrobial formulations that are used in a number of treatment modalities in endodontics. These include, inter-appointment intracanal medicaments, pulp-capping agents and root canal sealers. Calcium hydroxide formulations are also used during treatment of root perforations, root fractures and root resorption and have a role in dental traumatology, for example, following tooth avulsion and luxation injuries. The purpose of this paper is to review the properties and clinical applications of calcium hydroxide in endodontics and dental traumatology including its antibacterial activity, antifungal activity, effect on bacterial biofilms, the synergism between calcium hydroxide and other agents, its effects on the properties of dentine, the diffusion of hydroxyl ions through dentine and its toxicity. Pure calcium hydroxide paste has a high pH (approximately 12.5-12.8) and is classified chemically as a strong base. Its main actions are achieved through the ionic dissociation of Ca(2+) and OH(-) ions and their effect on vital tissues, the induction of hard-tissue deposition and the antibacterial properties. The lethal effects of calcium hydroxide on bacterial cells are probably due to protein denaturation and damage to DNA and cytoplasmic membranes. It has a wide range of antimicrobial activity against common endodontic pathogens but is less effective against Enterococcus faecalis and Candida albicans. Calcium hydroxide is also an effective anti-endotoxin agent. However, its effect on microbial biofilms is controversial.

Effectiveness of three solvents and two associations of solvents on gutta-percha and resilon

This study evaluated the effectiveness of 3 solvents (Citrol orange oil, Eucalyptol and Tetrachloroethylene) and 2 associations of solvents (Citrol orange oil+Tetrachloroethylene and Eucalyptol+Tetrachloroethylene) on 3 types of gutta-percha (conventional, thermoplastic and EndoREZ) and Resilon. Ten discs (10 mm diameter x 1 mm thick) from each material were prepared using standard metallic molds. Each specimen was weighed to determinate its initial mass. The specimens were immersed in the solvents for 10 min, followed by immersion in distilled water for 20 min, and were then reweighed to obtain the final mass. The mean weight loss determined the solvent capacity. Data were analyzed by ANOVA and Tukey's test at 5% significance level. Tetrachloroethylene was the most effective on conventional gutta-percha (p<0.05). Tetrachloroethylene was also the most effective on thermoplastic gutta-percha, but it was not significantly different (p>0.05) from Eucalyptol+Tetrachloroethylene, Citrol+Tetrachloroethylene, and Citrol. All solvents and associations presented little effectiveness on Resilon. The association Eucalyptol+Tetrachloroethylene was the most effective on EndoREZ, but it did not differ significantly (p>0.05) from Citrol+Tetrachloroethylene and Tetrachloroethylene. All evaluated substances presented solvent action. Tetrachloroethylene improved the effectiveness of both Citrol and Eucalyptol.

Comparative SEM evaluation of three solvents used in endodontic retreatment: an ex vivo study

This study compared, by scanning electron microscopy (SEM), the efficacy of three solvents on the removal of filling materials from dentinal tubules during endodontic retreatment. Forty human maxillary canines with straight canals were prepared according to a crown-down technique and enlarged to a#30 apical file size, before obturation with gutta-percha and a zinc-oxide-eugenol based sealer. The samples were stored for 3 months before being randomly assigned to four groups: chloroform (n=10), orange oil (n=10), eucalyptol (n=10) and control (n=10). Solvents were applied to a reservoir created on the coronal root third using Gates Glidden drills. The total time for retreatment using the solvents was 5 minutes per tooth. Following retreatment the roots were split longitudinally for SEM evaluation. SEM images were digitized, analyzed using Image ProPlus 4.5 software, and the number of dentinal tubules free of filling material from the middle and apical thirds was recorded. No significant difference was found among the solvent groups regarding the number of dentinal tubules free of root filling remnants in the middle and apical root thirds (p>0.05). However, the control group had fewer dentinal tubules free of filling material (p<0.05). Under the tested conditions, it may be concluded that there was no significant difference among the solvents used to obtain dentinal tubules free of filling material remnants.

In vitro evaluation of macrophage viability after incubation in orange oil, eucalyptol, and chloroform

OBJECTIVE

The aim of this study was to evaluate the cytotoxicity of orange oil, eucalyptol, and chloroform in a cell culture assay by using peritoneal macrophages from Swiss mice.

STUDY DESIGN

Control (Dulbecco's modified Eagle's medium [DMEM] plus 1.25% ethyl alcohol) and experimental (orange oil, eucalyptol, and chloroform) groups were studied. Solvents used were tested at 0.025% and 0.050% concentrations in DMEM plus 1.25% ethyl alcohol.

RESULTS

Orange oil, eucalyptol, and chloroform were all cytotoxic in comparison to the control group (P < .001). Orange oil showed the least cytotoxicity (P < .001). No significant differences were observed regarding cell viability when comparing the eucalyptol and chloroform groups (P < .05). There were significant differences in the cytotoxicity of eucalyptol and chloroform with an increase in concentration (P < .0001). Nevertheless, this difference was not significant in the orange oil group (P < .05).

CONCLUSION

Orange oil was less cytotoxic than eucalyptol and chloroform.

Dissolving efficacy of organic solvents on root canal sealers

The aim of this study was to evaluate the solubility of three types of root canal sealers in three organic solvents used in endodontics. The solubility of calcium-hydroxide-based (Sealer 26), silicon-polydimethylsiloxane-based (RoekoSeal), and zinc-oxide-eugenol based (Endofill and Intrafill) sealers was assessed in eucalyptol, xylol, orange oil, and distilled water. Eighty samples of each filling material were prepared according to the manufacturers' instructions and then divided into four groups for immersion in solvent for 2 or 10 min. The means of sealer dissolution in solvents were obtained by the difference between the original preimmersion weight and the postimmersion weight in a digital analytical scale. Data were statistically analyzed with the Student's t test, and multiple comparisons were performed with Student-Newman-Keuls. Xylol and orange oil showed similar effects, with significant solubilization (P<0.05) of the tested cements. Endofill and Sealer 26 did not show any significant difference in solubilization at the two immersion times, whereas RoekoSeal and Intrafill showed a more pronounced solubility at 10 min. The lowest levels of solubilization occurred in RoekoSeal, Sealer 26, Endofill, and Intrafill. It is concluded that xylol and orange oil presented similar solvent effects with a significant solubility of the tested cements.

The effect of AH 26 and AH Plus on MCF-7 breast cancer cell proliferation in vitro

AIM

The purpose of this study was to determine whether AH 26 and AH Plus have in vitro oestrogenic effects.

METHODOLOGY

MCF-7 breast cancer cells were trypsinized and plated in 24-well plates at initial concentrations of 10,000 cells per well in 5% FBS in DME. Cells were allowed to attach for 24 h; then the seeding medium was replaced with 10% CDHuS-supplemented phenol red-free DME. Different concentrations of the test compound were added to sample wells (AH 26 and AH Plus at 1/100 to 1/1,000,000 dilutions), 10 pM estradiol-17beta to positive controL and no sub-stance to negative control (hormone-free control cells). The assay was stopped after 144 h.

RESULTS

AH 26-powder induced MCF-7 cell proliferation in a dose-dependent manner. The cell yield obtained with AH 26-powder at 1/100 dilution sample was 2.5-fold greater than in control cultures. The sam-ple prepared with mixed AH 26 paste/powder 1:1 also induced MCF-7 cell proliferation, but showed less potency than AH 26-powder alone. The cell yield obtained with AH 26 paste/powder at 1/100 dilution sample was 1.9-fold greater than in control cultures. AH Plus did not show in vitro oestrogenic effect.

CONCLUSIONS

AH 26 showed in vitro oestrogenic effect, but not AH Plus. The endodontist must consider the possible oestrogenic effect of AH 26, as well as the cytotoxic effects of root filling materials, and avoid the leakage of sealer through the apex during root canal treatment.

A comparison of the effectiveness of chloroform and eucalyptus oil in dissolving root canal sealers

OBJECTIVE

The solubility of 8 different root canal sealers in chloroform and in eucalyptus oil was compared.

STUDY DESIGN

For standardized samples (n=12), ring molds were filled with mixed sealers based on epoxy resin, silicone, calcium hydroxide, zinc oxide-eugenol, glass ionomer, and polyketone. These samples were immersed in chloroform or eucalyptus oil for 30 seconds, 1 minute, 2 minutes, 5 minutes, 10 minutes, and 20 minutes. Then, the mean weight loss was determined and statistically analyzed.

RESULTS

With the exception of the silicone, all the sealers showed significantly higher solubilities (P <.05) in chloroform than in eucalyptus oil. Epoxy resin was the most soluble sealer in chloroform. In eucalyptus oil, calcium hydroxide, and zinc oxide-eugenol showed the highest solubility.

CONCLUSION

Under the conditions of this study, chloroform was a far more effective solvent of root canal sealers than eucalyptus oil. Because of the potential hazards of chloroform, further studies on the dissolution of root canal sealers in different solvents seem to be necessary.