Removal Efficiency of Calcium Hydroxide Intracanal Medicament With Two Calcium Chelators: Volumetric Analysis Using Spiral CT, An In Vitro Study

Efficacy of 2% Paradichlorobenzene, 10% Citric Acid, 17% Ethylenediaminetetraacetic Acid, and 0.2% Chitosan at Removing Calcium Hydroxide From the Root Canals

INTRODUCTION

Chronic infections often require the use of an intracanal medicament. Calcium hydroxide is the most commonly used intracanal medicament. However, retrieval of calcium hydroxide (CH) medicaments is a challenge.

AIM

This study evaluated the efficacy of 2% paradichlorobenzene, 10% citric acid, 17% ethylenediaminetetraacetic acid (EDTA), and 0.2% chitosan in removing calcium hydroxide from the root canals.

METHODS AND MATERIALS

Forty single-rooted mandibular premolars extracted for orthodontic reasons were selected for the study. After access opening, cleaning and shaping were performed following a standardized irrigation protocol, and the samples were pre-weighed for baseline weight. CH was placed in canals until the apex, and the specimen was incubated at 37 °C and 100% relative humidity for seven days. These samples were weighed again for quantitative analysis and subjected to cone beam computed tomography (CBCT) for volumetric analysis using ITK SNAP software (Penn Image Computing and Science Laboratory (PICSL), University of Pennsylvania, Philadelphia, PA). The samples were randomly divided into four groups based on the irrigant used for the removal of medicament. Group 1: 2% paradichlorobenzene; group 2: 10% citric acid; group 3: 17% EDTA; and group 4: 0.2% chitosan, all in combination with sonic agitation. After the removal of CH, weight and volumetric analyses were repeated, and the percentage difference was calculated.

STATISTICAL ANALYSIS

Statistical analysis was done using the one-way ANOVA test for both weight and volumetric assessment, and the inter-group comparison was made using the post hoc Tukey test.

RESULTS

The maximum retrieval was observed with 2% paradichlorobenzene by both weight (96.75%) and volumetric (91.42%) assessment, with p=0.00 and p=0.01, respectively. This was followed by 0.2% chitosan, 10% citric acid, and the least, 17% EDTA.

CONCLUSION

Two percent paradichlorobenzene combined with sonic agitation was most efficient in removing CH, followed by 0.2% chitosan, 10% citric acid, and 17% EDTA chitosan.

Effect of conventional needle irrigation, passive ultrasonic irrigation, sonic irrigation and XP-endo finisher in removing intracanal Vitapex paste

To compare the efficiency of conventional needle irrigation, passive ultrasonic irrigation, sonic irrigation and XP-endo Finisher in removing Vitapex paste from root canals. The root canals of human single-rooted teeth were prepared and obturated with Vitapex paste. After 2 weeks, the 48 teeth were randomly allocated into four groups: conventional needle irrigation (CNI) group, passive ultrasonic irrigation (PUI) group, sonic irrigation (SI) group and XP-endo Finisher (XP) group. The specimens of four groups were scanned using a micro-computed tomography after the Vitapex pastes was removed. The results showed that more residual paste was left in the CNI group than in the other three groups (p < 0.05). There was no significant difference among the PUI, SI and XP group (p > 0.05). And, the majority of the residual Vitapex was found in the apical third, with a small amount in the middle third after using any of the three agitated irrigation techniques.

Full counterclockwise rotary motion kinematics enhances the removal of gutta-percha and bioceramic sealer from root canals: A computed tomographic study

Background and Aim

Complete removal of gutta-percha and sealer is an important step during retreatment. The aim of this study was to assess the efficacy and time taken by full counterclockwise rotary motion of a reciprocating file in the removal of gutta-percha and BioRoot™ RCS bioceramic sealer.

Materials and Methods

Thirty-six extracted human mandibular premolars were instrumented with Mtwo rotary files and obturated using lateral condensation technique with gutta-percha and BioRoot™ RCS bioceramic sealer. The teeth were divided into three retreatment groups (n = 12) based on the kinematics used: Group I, Mtwo retreatment (Mtwo-R) files; Group II, Reciproc files used in reciprocation mode (Reciproc-R); and Group III, Reciproc files used in full counterclockwise motion (Reciproc-CCW). The efficacy of gutta-percha and bioceramic sealer removal was assessed by volume of gutta-percha removed using cone-beam computed tomography and area of remaining gutta-percha and bioceramic sealer using ImageJ software after longitudinal sectioning. Statistical analysis was done by one-way analysis of variance test and Tukey's multiple post hoc tests.

Results

Reciproc-CCW motion was significantly efficient in the removal of gutta-percha and bioceramic sealer in comparison to Mtwo-R files and Reciproc-R. The time taken for gutta-percha and sealer removal was least for Reciproc-R (325.5 ± 101.68 seconds) and was statistically significant in comparison to the other groups.

Conclusion

Within the limitations of the study, Reciproc-CCW was an effective method of removal of gutta-percha and bioceramic sealer during retreatment.

The impact of provisional intraradicular retainers cementation with temporary methacrylate-based resin in the bond strength of glass fiber posts to root dentin

Chemical composition of temporary cements interferes in the bond strength and quality of the bond interface of glass fiber posts to root dentin. The aim of the present study was to evaluate the influence of different temporary cements on the bond strength of fiberglass posts and resin cement. Thirty-two maxillary central incisor roots were standardized at 15 mm length. The root canals were prepared with Reciproc R50 and filled with a R50 single cone and AH Plus. Ten mm of filling material was removed with a heated Schilder condenser, leaving 5 mm of apical filling material. The roots were randomly distributed into 4 groups (n = 8). In the control group, the root canal was prepared with a standard drill according to the post diameter (DC #1, FGM, Joinville, Brazil), irrigated with 5 mL of distilled water and immediately received the fiberglass post cemented with self-adhesive resin cement. For the other groups, cores were made with temporary intraradicular retainers cemented with different temporary cements: methacrylate-based resin (Bifix Temp - Voco), calcium hydroxide-based (Provicol - Voco) and zinc oxide-based - eugenol-free (Relyx Temp NE - 3M). After 7 days, mechanical removal of the temporary retainers, preparation, irrigation of the root canal and cementation of the fiberglass post were performed, following the same protocol that had been performed in the control group. The roots were sectioned to obtain 3 slices per root third. The most cervical section of each third was used for the push-out test and failure pattern analysis, while the most apical section was subjected to analysis of the adhesive interface by scanning electron microscopy (SEM). The BS data were compared between groups using the two-way ANOVA and Tukey post-test. The failure pattern results were expressed in percentage and compared between groups using the chi-square test and the material adaptation data at the bond interface were evaluated using the Kruskal-Wallis and Dwass-Steel-Critchlow-Fligner tests. The results showed higher BS in the cervical third, with a higher value in the control group (10.8 ± 0.94) and Bifix Temp group (9.78 ± 0.71), with no statistically significant difference between these groups (P > .05). The middle and apical thirds showed no statistically significant difference (P > .05). As regards the type of failure, a higher percentage of mixed adhesive failures was observed for all groups. Analysis of the adhesive interface by SEM showed that the temporary cement Bifix Temp showed greater adaptation at the bond interface. It was concluded that the methacrylate-based resin temporary cement showed the highest bond strength values and best adaptation to root dentin than the zinc oxide-based and calcium hydroxide-based temporary cements.

Intracanal calcification following regenerative endodontic treatment: a systematic review and meta-analysis

OBJECTIVES

Calcification is a common finding in endodontic cases after regenerative endodontic therapy (RET). We aimed to identify the prevalence of intracanal calcification after RET and to compare intracanal calcification outcomes in RET using either calcium hydroxide [Ca(OH)₂] or antibiotics.

MATERIALS AND METHODS

We searched PubMed, Web of Science, ProQuest Dissertations & Theses, and Scopus databases for clinical, cross-sectional, case-control, and cohort RET studies published until May 2020 in the English language and reporting a calcified case after RET. The Cochrane risk-of-bias tool for randomized trials and Risk of Bias In Non-randomized Studies of Interventions were used for bias assessment. Meta-analyses were performed, overall and separately, for intracanal medicaments using a random-effects model with weighted inverse variance methods. Subgroup analysis was performed according to the calcification type.

RESULTS

Eight studies were included. The overall prevalence of intracanal calcification after RET was 30.7% (95% confidence interval [CI]: 0.15-0.45,[Formula: see text]=92.6%), 46.5% with Ca(OH)₂ vs. 25.8% with antibiotic-based intracanal medicaments. Subgroup analyses for complete calcification outcome showed a higher prevalence of complete calcification in the Ca(OH)₂ group (46.5%, 95% CI: 0.17-0.68,[Formula: see text]%) than in the antibiotic group (10%, 95% CI: - 0.04-0.43,[Formula: see text]%).

CONCLUSIONS

Based on the studies included, available evidence shows a statistically significant association between complete calcification and Ca(OH)₂ paste as an intracanal medicament. Other contributing factors, such as blood clot formation and follow-up time, might also play an essential role in forming intracanal calcification.

CLINICAL RELEVANCE

This study highlights the significant association between complete calcification and Ca(OH)₂ paste.

Laser-fluorescence assessment of sodium hypochlorite quenching reversal agents on human dentine

BACKGROUND

Laser-fluorescence diagnostic technology for real-time clinical assessment of residual bacteria could help assist in determining the endpoints for root canal debridement. Sodium hypochlorite (NaOCl) can however quench fluorescence and lead to false low reading. This study aims to evaluate various antioxidant for their ability to recover quenched fluorescence in dentine treated with NaOCl.

METHODS

Human dentine fluorescence was measured using 655 nm laser at baseline and again after a 2 min application of 4% NaOCl. The putative recovery agents were then applied, and the fluorescence measured after 5, 10, 20, 30 and 60 min. Recovery from quenching was also assessed using laser confocal scanning microscopy (CLSM) with a bound tetracycline fluorophore using 488 nm excitation.

RESULTS

A 5 min application of vitamin E oil or buffered 2% lignocaine solution (1:80,000 adrenaline) was effective in regaining quenched fluorescence within the following 5 mins. Distilled water, sodium thiosulfate, unbuffered 2% lignocaine with 1:80000 adrenaline and phosphate buffered saline were less effective, and of equal performance. Ascorbic acid and butylated hydroxyanisole were not effective and had deleterious effects on the levels of dentine fluorescence. CLSM provided confirmation of recovery from quenched fluorescence using vitamin E oil.

CONCLUSION

Based on these findings, reversal agents should be employed when assessing the fluorescence of dentine that has been exposed to NaOCl or other quenching agents.

Removal efficacy of propolis/calcium hydroxide medicaments from the root canal

Objective:

To compare the removal efficacy of propolis and calcium hydroxide medicaments from the root canal using manual irrigation with sodium hypochlorite.

Methods:

A randomized controlled trial was conducted at the Department of Restorative Dentistry and Endodontics, College of Dentistry, King Faisal University for two months. Thirty single-rooted upper or lower permanent anterior teeth with sound root and closed apex were selected. After cleaning and shaping of canal by protaper rotary, teeth were randomly divided into two groups. In group “A,” propolis paste was placed while calcium hydroxide was placed inside root canals in group “B,” followed by temporary restoration. After seven days, intracanal medicament was removed using 25 # K file and irrigated canal by 5 ml of 3.0% sodium hypochlorite. A final irrigation of 2-ml of 17% EDTA for three minutes followed by 1-ml of normal saline was performed. A diamond disc was used to cut the crowns of the teeth from cemento-enamel junction and divide the roots into two halves. These sectioned halves were then observed under a stereomicroscope at 7X magnification and analyzed using Adobe Photoshop. Magnetic lasso tool was used to calculate the percentage of residual medicament in the canals by comparing the pixel proportion of the medicament with the total pixel proportion of the canal. Paired t-test was used to see the difference in the number of remaining remnants between propolis and calcium hydroxide. A p-value of less than 0.5 was considered statistically significant.

Results:

A statistically significant difference (p-value < 0.001) was observed in the percentage of remaining remnants between propolis (23.22%) and calcium hydroxide (38.58%) after thorough irrigation with sodium hypochlorite.

Conclusion:

Propolis is superior to calcium hydroxide in terms of their removal potency from the root canal after thorough irrigation with sodium hypochlorite.

The effects of root canal perforation repair materials on the bond strength of fiber posts

INTRODUCTION

This study aimed to evaluate the effect of calcium hydroxide and bioceramics used in perforation repair on the bonding strength of fiber posts via a push-out test.

METHODOLOGY

This study used 106 extracted single-rooted human mandibular premolar teeth. Root canal preparations were performed with a rotary file system and perforations were created in the middle third of each tooth. The samples were randomized into two main experimental groups, one with calcium hydroxide and one without. Each group had four subgroups in which different bioceramic cements were applied (n = 11) and a control group (n = 9). The root canals perforations were repaired using MTA, Biodentine, Bioaggregate, and Endosequence BC root repair material. A fiber post was applied to each tooth and a push-out test was performed. The samples were examined at 40× magnification with a digital microscope in order to identify fracture type.

RESULTS

Bonding strength was calculated in MPa. A statistical analysis showed that the calcium hydroxide had no effect on the bonding strength of the fiber posts. A comparison of the perforation repair materials revealed that Biodentine in the calcium hydroxide group and Bioaggregate in both groups decreased the bonding strength compared to the other materials (p < 0.05). The most common failure type was adhesive failure between the dentin and resin cement (38.16%).

CONCLUSIONS

The use of different perforation repair materials can affect the bonding strength of fiber posts. Therefore, the choice of perforation repair material should be made on an individual basis.

Efficacy of passive ultrasonic irrigation in the removal of three different intracanal medicaments - An in-vitro study

Background

A successful root canal treatment involves the elimination of microorganisms, and prevents them from reinfecting the root and/or peri-radicular tissues. This can be mainly achieved by efficient cleaning and shaping of the root canal system. Due to the complexity of the root canal morphology, hand and rotary files cannot clean areas such as the isthmuses and lateral canals. In such cases, effective irrigation and the use of intracanal medicaments are essential. Medicaments that are applied should be removed before obturation.

Aim

To evaluate the efficacy of passive ultrasonic irrigation in the removal of three different intracanal medicaments - Triple antibiotic paste (TAP), Odontopaste, and Metapex using a stereomicroscope.

Methodology

A total of 45 single-rooted human teeth were selected and decoronated. The root canals were shaped with ProTaper rotary files. The specimens were fixed in modified Eppendorf vials with silicone material. The roots were split longitudinally, and a standardized groove was prepared in the apical part. The teeth were randomly divided into three groups each containing 15 samples based on the intracanal medicament used: TAP, Odontopaste, and Metapex.

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The root halves were reassembled with sticky wax and remounted in the Eppendorf vial. Each specimen was irrigated with 3% NaOCl and agitated using a passive ultrasonic device. The root segments were disassembled. Digital images were obtained using a stereomicroscope.

Results

The data were evaluated statistically using Kruskal-Wallis and Mann-Whitney U tests. There was a statistically significant difference in the remaining intracanal medicament score (P < 0.05).

Conclusion

Odontopaste showed the least remaining amount score, whereas TAP and Metapex showed greater retention within the dentin.

Efficacy of the Rotary Instrument XP-Endo Finisher in the Removal of Calcium Hydroxide Intracanal Medicament in Combination with Different Irrigation Techniques: A Microtomographic Study

OBJECTIVES

This study aims to evaluate the efficacy of the rotary instrument XP-endo Finisher for the removal of Ca(OH)₂ aided by different irrigation regimens.

METHODS

Sixteen double-rooted upper premolar human teeth were selected for the study. Thirty-two canals were prepared using a ProTaper Next rotary system up to X3. Then, the canals were filled with Ca(OH)₂. The volume of Ca(OH)₂ inside the canals was measured by microcomputed tomography (micro-CT). After that, the teeth were randomly allocated into two experimental groups, i.e., A and B (n = 16 canals). In group A, Ca(OH)₂ was removed using the master apical file (X3). In group B, Ca(OH)₂ was removed using a XP-endo finisher. In half of both groups (n = 8), syringe irrigation (SI) was used, while passive ultrasonic irrigation (PUI) was used for the other half. After removal, the remaining volume of Ca(OH)₂ was measured. All data were statistically analyzed using two-way ANOVA with Tukey's post hoc test.

RESULTS

The percentages of remaining Ca(OH)₂ in the apical thirds of all canals were significantly higher as compared with the middle and coronal thirds in all groups (p < 0.05). There was no significant difference between different files and techniques (p > 0.05).

CLINICAL SIGNIFICANCE

This study presents a new method for the removal of Ca(OH)₂ from root canals.

Calcium Silicate-Based Cements as Root Canal Medicament

Purpose

This study aims to retard the setting reaction of CSC by mixing it with 2% chlorhexidine gel (CHX) which will be used as an intracanal medicament, and to evaluate the removal of the experimental medicaments from the root canal.

Materials and Methods

White Portland cement, white ProRoot MTA and Biodentine were mixed with 2% CHX. The setting time, flowability and film thickness of the CSC/CHX mixture (experimental medicaments) were assessed and measured following the standards of ISO specification. Calcium ion release was measured using ICP-OES, while pH was tested using a pH meter. Moreover, twenty single-rooted teeth were filled with the experimental medicaments for seven days, then the medicaments were removed and the samples analyzed using SEM. Calcium hydroxide paste was used as a control.

Results

The setting time of the experimental medicaments was inhibited until 84 days. The calcium ion release of the experimental medicaments was significantly higher compared to the control over the period of 14 days (P<0.001). The mean pH value was above 11.45 for all tested materials over a period of 14 days, with no significant difference between them (P<0.05). There was no significant difference in film thickness of the experimental medicaments compared to the control (P> 0.05). However, the flowability of the experimental medicaments was significantly higher than the control (P<0.05). SEM showed no significant differences in the removal of the intracanal medicaments between all the tested groups.

Conclusion

The addition of 2% CHX to CSCs retarded or inhibited its setting reaction over a period of 84 days. The calcium ion release and flowability of these experimental medicaments was found to be better than calcium hydroxide. Removal of the intracanal medicaments from the root canal was successfully achieved in all groups. Therefore, these experimental medicaments have the potential to be used as an enhanced root canal medicament.

Comparison of Two Different Methods in the Removal of Oil-Based Calcium Hydroxide From Root Canal System: A Triple-Blinded Randomised Clinical Trial

OBJECTIVE

To compare the effectiveness of rotary master apical file (RMAF) with ultrasonic activation of endodontic file (UAF) in the removal of silicon oil-based calcium hydroxide (SOBCH) from the canal.

METHODS

Ethical review committee approval and informed consent was obtained. 60 cases with necrotic teeth in which silicon oil-based intracanal medicament (Metapex) was to be placed were randomised in one of the two groups using sealed envelopes containing assignment codes for medicament removal: RMAF and UAF group. After standard protocol of coronal access, cleaning and shaping, silicon oil-based SOBCH was placed using a Lentulo spiral. A periapical radiograph was taken after SOBCH placement to check for adequate adaptation. On 7th day, after instrumentation and medicament removal according to respective group, a second radiograph was taken to evaluate the effectiveness. Effectiveness was calculated using a graded scale in which 0 and 1 are effective and 2 and 3 are ineffective cleaning. Teeth were statistically analyzed using the Mann Whitney U and Chi-square test.

RESULTS

There was no statistically significant difference in the removal effectiveness of group RMAF and Group UAF at coronal (P=0.74) middle (P=0.71) and apical third (P=0.68). According to the graded score both techniques were equally effective in cleaning at all thirds of canal (RMAF=Apical: 1.09+-0.70, Middle: 0.61+-0.80, Coronal: 0.33+-0.48 and UAC=Apical: 1.00+-0.77, Middle: 0.52+-0.74, Coronal: 0.28+-0.46). Effectiveness of SOBCH removal using the two methods was not statistically significant between maxillary and mandibular teeth (P=0.35).

CONCLUSION

Both the removal methods, Ultrasonic activation of file and Rotary master apical file, for SOBCH were equally effective in all the thirds of canal. And none of the techniques were able to completely remove the SOBCH. Effectiveness of SOBCH removal using the two methods was not statistically different between maxillary and mandibular teeth. (EEJ-2020-07-183).

Computed microtomography evaluation of calcium hydroxide-based root canal dressing removal from oval root canals by different methods of irrigation

The aim of this study was to evaluate the capacity of conventional irrigation, passive ultrasonic irrigation (PUI), and Easy Clean for removing calcium hydroxide-based root canal dressing from oval root canals. Thirty mandibular uniradicular incisors with oval canals were used, and subjected to chemical-mechanical preparation with Reciproc R40 instruments. The main canal was filled with a paste based on Ca(OH)₂ P.A., iodoform and propylene glycol in the ratio of 3:1:1. The teeth were stored in 100% humidity at a temperature of 37°C for 14 days. Afterwards, the teeth were divided into three groups (n = 10) according to the method of irrigation used (conventional irrigation, PUI, and Easy Clean). The specimens were analyzed by computed microtomography at three time intervals: before placing the root canal dressing, with the root canal dressing in place, and after application of the irrigation methods for removing it. The data were submitted to Kruskal-Wallis and Dunn tests for analyzing the canal as a whole, and Friedman and Dunn for analyzing the root thirds. The results showed that conventional irrigation was less efficient for removing the root canal dressing in comparison with the methods that agitated the irrigant solution (p < .05). When the root canal was analyzed as a whole, Easy Clean, and PUI were similar (p > .05). In analysis of the thirds, Easy Clean was more efficient than conventional irrigation in all the thirds, while PUI showed this behavior only in the cervical third (p < .05). The authors concluded that in oval canals, none of the irrigation methods were capable of removing all the root canal dressing, however, the methods that agitated the irrigant solution were more efficient than conventional irrigation.

Evaluation of the effect of calcium hydroxide and endodontic irrigants on the push-out bond strength of fiber post - an in vitro study

Background

In recent years, fibre-reinforced composite posts have been proposed for the restoration of root filled teeth as an alternative to pre-fabricated posts or metal dowels.

Aims and objectives

The aim of the study was to analyze the effect of endodontic irrigants used for removal of calcium hydroxide on the push-out bond strength of fiber posts to root canal dentin.

Methods

Forty human permanent single-rooted mandibular premolars with relatively straight roots were taken and access cavities were prepared and biomechanical preparation done using Rotar Y protaper file till size F2. The samples were divided into Experimental group and Control group. In Experimental groups Intracanal dressing of calcium hydroxide was removed by 2.5% NaOCl and 17% EDTA (Group1), MTAD (Group II) and Qmix (Group III). Control group did not receive Intracanal calcium hydroxide dressing. Canals were obturated using size F2 protaper gutta-percha points and AH plus sealer. After storage for 24 hours, post space was prepared. Forty Tenax fiber post (Coltene) were cemented with Rely X U200 resin. The roots were then transversally sectioned into 3 slices of 1mm thickness corresponding to cervical, middle and apical third. The slices obtained were subjected to micro-push-out bond strength test using a universal testing machine. The data obtained was subjected to statistical analysis using One-Way ANOVA test. P value of .05 was considered as statistically significant level.

Results

The mean push-out bond strength values for controls, NaOCl/EDTA, MTAD and QMIX group at cervical third were 10.17, 15.84, 20.39 and 20.98 whereas at apical third 4.78, 8.85, 11.66 and 12.10.

Conclusion

Qmix showed higher push-out bond strength values followed by MTAD and NaOCl/EDTA. All the groups showed lowest push-out bond strength values in the apical third followed by middle and the maximum in the cervical region.

Effects of calcium hydroxide reagent on the bond strength of resin cements to root dentin and the retention force of FRC posts

The aim of this study was to determine the effects of calcium hydroxide (Ca(OH)₂) treatment on bond strength of resin cements to root dentin and retention force of fiber-reinforced composite (FRC) posts. Bovine root dentin was endodontically prepared and treated with Ca(OH)₂ for 7 days. Root dentin for bond strength test was adhered to resin-composite with resin cements. For pull-out test, posts consisting of FRC posts and resin-composites were fabricated and cemented to root. Shear bond and pull-out tests were performed using a universal testing machine. No significant differences in bond strength and post retention force were found between Ca(OH)₂ treated and untreated groups. Significant differences were found among the cements. A positive correlation was indicated between bond strength of cements and retention force of FRC posts. In conclusion, Ca(OH)₂ treatment on root dentin did not affect bond strength of resin cements and retention force of FRC posts.

The XP-Endo Finisher for the removal of calcium hydroxide paste from root canals and from the apical third

Background

The aim was to compare the efficacy of the passive ultrasonic irrigation PUI and the Xp-endo Finisher (FKG-Dentaire, La-Chaux-de-Fonds, Switzerland) in removing the calcium hydroxide paste from root canals and from the apical third.

Material and Methods

Sixty-eight root canals of single-rooted teeth were shaped using the BT-Race files (FKG-Dentaire, La-Chaux-de-Fonds, Switzerland). Ca(OH)2 was placed in all samples except for the negative control group (n=4). Remaining teeth were randomly divided into three groups: G1-Xp (n=30), G2-PUI (n=30) and the positive control group (n=4). Removal procedure consisted of three repeated one-minute-cycles. Samples were split longitudinally, photos of halves were taken at X6.4 magnification and were analyzed using the ImageJ-Software (The National Institutes of Health NIH, Bethesda, Maryland, USA) to calculate the percentage of surfaces with residual Ca(OH)2; the results were compared using the Wilcoxon-Mann Whitney test. Photos of the apical thirds were taken at X16 and X40 magnifications and were scored by two examiners from (0) to (4). Scores of the apical third were compared using the Fisher test.

Results

The Xp-endo Finisher removed completely the Ca(OH)2 dressing from four teeth (13.33%) whereas the PUI in one tooth (3.33%). The mean values of the remaining Ca(OH)2 were (2.1%, 3.6%) respectively and the difference was not significant (p= 0.195). Both examiners found the Xp-endo Finisher more efficient in the apical third and the difference was significant; p= (0.025, 0.047) respectively.

Conclusions

The Xp-endo Finisher showed a superiority over the PUI in removing the Ca(OH)2 from the apical third after 3 minutes of activation.

Key words:Calcium hydroxide removal, Passive ultrasonic irrigation, Xp-endo Finisher.

Comparison of different techniques for removal of calcium hydroxide from straight root canals: an in vitro study

To compare four different techniques for removal of calcium hydroxide from straight root canals. The present study used the design suggested by Lee et al. (Int Endod J 37:607-612, 32) and van der Sluis et al. (Int Endod J 40:52-57, 17). One-hundred and ten extracted human teeth with straight root canals were prepared to ISO-size 50 and split longitudinally. Two lateral grooves were prepared, filled with calcium hydroxide and the root halves reassembled in a muffle. Calcium hydroxide was removed using one of five techniques: (1) passive ultrasonic irrigation, (2) hydrodynamic irrigation using RinsEndo^®, (3) sonic irrigation using the EndoActivator^®, (4) motor-driven plastic brush (CanalBrush™), and (5) manual irrigation with a syringe as the control group. Distilled water was used as irrigant. Cleanliness of the grooves was scored under a microscope with 40× magnification. For intraindividual reproducibility and interrater agreement, Cohens Kappa was calculated. Results of scoring were analyzed using a non-parametric test. Post hoc pairwise comparisons were used for irrigation techniques (α = 0.05). Passive ultrasonic irrigation performed significantly better than all other groups in the apical groove. Significant differences were found between RinsEndo and CanalBrush (P = 0.01855) and CanalBrush and syringe irrigation (P = 0.00021). In the coronal groove, passive ultrasonic irrigation performed significantly superior and hand irrigation performed significantly worse than all other groups. A statistically significant interaction was shown between irrigation technique and localization of the groove (P = 0.01358). The coronal grooves showed more remaining calcium hydroxide than the apical grooves. Complete removal of calcium hydroxide from the root canal could not be achieved with any of the techniques investigated. The highest degree of cleanliness resulted from the use of passive ultrasonic irrigation.

A novel model for testing the efficiency of removal of calcium hydroxide from complex root canal anatomies

The purpose of this study was to evaluate the efficacy of several irrigation protocols in the removal of calcium hydroxide [Ca(OH)₂ ] from simulated internal root resorption cavities in a complex root canal anatomy model. The 20° to 35° curved mesiobuccal roots of 94 maxillary molars were sectioned longitudinally; internal resorption cavities were prepared in the apical third of the canal walls. Calcium hydroxide was placed into the cavities and the root halves reassembled. Four teeth were used as controls, and 90 teeth were randomly divided into six experimental groups (n = 15), according to the irrigation protocols used: syringe irrigation; H₂ O₂ (HP); Navitip FX; Vibringe-syringe; Vibringe-NaviTip FX; ultrasonically activated irrigation (UAI) using an ultrasonic K-file. In the HP group, 2.5% NaOCl and 3% H₂ O₂ were used, while 2.5% NaOCl and 17% EDTA were used in the remaining groups. Stereomicroscope images and radiographs were used to measure the remaining Ca(OH)₂ . The model proved to be suitable for simulating complex anatomy. Positive correlation was found between stereomicroscope and radiographic analyses (P < 0.05). UAI removed significantly more Ca(OH)₂ than the other experimental groups (P < 0.05). The HP group was the least efficient protocol (P < 0.05). It would appear that a reliable model has been developed that simulates complex root canal anatomy. Irrigant activation protocols enhanced Ca(OH)₂ removal.

A cone-beam computed tomography assessment of the efficacy of different irrigation devices for removal of silicone oil-based calcium hydroxide from root canal system

BACKGROUND

Most often used intracanal medicament is calcium hydroxide (Ca(OH)₂). Removal of Ca(OH)₂ before obturation is mandatory. Different irrigation solutions and devices were tested in the previous study for this purpose.

AIM

The aim of this study was to evaluate the comparative efficacy of different irrigation techniques in removing intracanal medicament using cone-beam computed tomography (CBCT).

MATERIALS AND METHODS

Cleaning and shaping was carried out in 42 freshly extracted single-rooted mandibular first premolars using Protaper Rotary Files. Intracanal medicament (silicone oil-based Ca(OH)₂ paste) was placed and left for 2 weeks in the root canal. Medicament was then removed by five different irrigation techniques: EndoActivator, EndoVac, ultrasonic irrigation with Endo-U-File, F-file, and Max-i-Probe needle. Changes in volume percentage were measured using CBCT and results were statistically analyzed using Levene's statistics and ANOVA.

RESULTS

Remnants of Ca(OH)₂ were found in all experimental groups. No significant difference was detected among the groups. F-file showed maximum removal efficacy of approximately 48%.

CONCLUSION

(1) There is no statistically significant difference between any irrigation technique for removal of oil-based Ca(OH)₂. (2) F-file demonstrated better results among all the other systems.

Comparison of efficiency of ethylenediaminetetraacetic acid, citric acid, and etidronate in the removal of calcium hydroxide intracanal medicament using scanning electron microscopic analysis: An in-vitro study

Context:

Being integral to root canal therapy, obturation can be performed adequately only after the removal of intracanal medicament. One technique involves the use of chelating agents such as ethylenediaminetetraacetic acid (EDTA) and citric acid. Etidronic acid, a relatively new chelator, has smear layer removal ability and lesser dentinal erosion. It is untested in calcium hydroxide (Ca[OH]₂) medicament removal.

Aim:

The aim of this study was to compare the efficiency of irrigation protocols (EDTA, citric acid, and etidronate) in Ca(OH)₂ removal.

Materials and Methods:

Forty-five single-rooted mandibular premolars were decoronated, instrumented, and filled with Ca(OH)₂. After 7 days incubation, Ca(OH)₂ was removed by three irrigation protocols (Group-I: 17% EDTA; Group-II: 10% citric acid; and Group-III: 18% etidronate). Roots were split and analyzed (scanning electron microscope, ×1500). Chelator solution pH was tested. Data were analyzed by Kruskal–Wallis ANOVA and Mann–Whitney U-test.

Results:

Group-III (coronal-third) and Groups-I and II (middle-third) had highest cleanliness scores; Groups-II and III (apical-third) had lowest scores. Comparing the thirds, all groups showed difference in scores. pH of Groups-I, II, and III were 6.8, 1.4, and 0.3, respectively.

Conclusion:

The solution pH of citric acid and etidronate impacts their Ca(OH)₂ removal efficiency in different ways: the highly alkaline pH of Ca(OH)₂ increases citric acid pH toward neutrality, where it becomes an inefficient chelator; on the contrary, high acidity of etidronate compensates for its weaker chelation. Etidronate may not require 5 min duration for Ca(OH)₂ removal due to the likelihood of dentinal erosion.

Retrievability of calcium hydroxide intracanal medicament with three calcium chelators, ethylenediaminetetraacetic acid, citric acid, and chitosan from root canals: An in vitro cone beam computed tomography volumetric analysis

Aim:

This study compared the amount of aqueous-based and oil-based calcium hydroxide remaining in the canal, after removal with two different chelators 17% EDTA, 20% Citric acid and 0.2% Chitosan in combination with ultrasonic agitation.

Methods and Material:

Cleaning and shaping of root canals of 28 mandibular premolar was done and canals were filled either with Metapex or Ca(OH)₂ mixed with distilled water. Volumetric analysis was performed utilizing cone beam-computed tomography (CBCT) after seven days of incubation. Ca(OH)₂ was removed using either 17% EDTA, 20% Citric acid or 0.2% Chitosan in combination with ultrasonic agitation.

Statistical analysis used:

Volumetric analysis was repeated and percentage difference was calculated and statistically analyzed using Kruskal-Wallis and Mann-Whitney U test.

Results:

All the three chelators failed to remove aqueous-based as well as oil-based Ca(OH)₂ completely from the root canal. Aqueous-based Ca(OH)₂ was easier to be removed than oil-based Ca(OH)₂. 0.2% Chitosan in combination with ultrasonics performed better than 17% EDTA and 20% citric acid in removal of Ca(OH)₂.

Conclusion:

Combination of 0.2% Chitosan and ultrasonic agitation results in lower amount of Ca(OH)₂ remnants than 17% EDTA, 20% Citric acid irrespective of type of vehicle present in the mix.

Effect of Calcium Hydroxide Based Intracanal Medicaments on the Apical Sealing Ability of Resin Based Sealer and Guttapercha Obturated Root Canals

INTRODUCTION

Calcium Hydroxide (CH) is one of the most commonly used intracanal medicaments which can be used with various vehicles.

AIM

The aim of this in vitro study was to evaluate the effect of three CH based intracanal medicaments on the apical sealing ability of AH Plus - guttapercha obturation.

MATERIALS AND METHODS

Crowns of 100 extracted single rooted human teeth were sectioned at the Cemento-Enamel Junction (CEJ) to a standardized length. The root canals were instrumented upto ISO size 40 using step back technique and the specimens were randomly divided into two control and four experimental groups. The control groups were not medicated. Specimens in positive control group (Group I) were obturated with guttapercha without placing sealer and in negative control group (Group II) were obturated with guttapercha and AH Plus sealer. Among the experimental groups, specimens of Group III were not medicated while groups IV, V and VI were medicated with CH-saline, CH-2% Chlorhexidine (CHX) and Vitapex respectively for a period of 14 days. The medicaments were removed from the specimens and the teeth were obturated with AH Plus sealer and guttapercha using lateral compaction technique. The specimens were immersed in India ink dye, demineralized and diphanized. The extent of dye penetration was assessed using a 10X stereomicroscope. Data obtained was statistically analyzed by one-way ANOVA (p<0.05) followed by Post-hoc Tukey test.

RESULTS

Amongst the three CH medicaments, CH-2% CHX when used as an intracanal medicament showed a significantly higher microleakage as compared to the other groups with p<0.001. The microleakage values between the remaining groups were not statistically significant.

CONCLUSION

Under the conditions of this study it was concluded that all groups with or without intracanal medicament showed apical leakage. The vehicle used to carry CH may significantly influence the apical sealing ability of guttapercha - AH Plus obturated canals.

Effect of Laser-Activated Irrigation with Ethylene Diaminetetraacetic Acid and Phytic Acid on the Removal of Calcium Hydroxide and Triple Antibiotic Paste from Root Dentin

OBJECTIVE

This study assessed the efficacy of erbium, chromium:yttrium-scandium-gallium-garnet (Er,Cr:YSGG) laser-activated irrigation (LAI) of ethylene diaminetetraacetic acid (EDTA) and phytic acid on the removal of calcium hydroxide (CH) and triple antibiotic paste (TAP) from root canals.

BACKGROUND DATA

Although some studies investigated the efficacy of LAI of EDTA irrigation, no study has been conducted to investigate the efficacy of LAI of phytic acid in the removal of CH and TAP from root dentin.

MATERIALS AND METHODS

Root canals of extracted maxillary incisors (n = 80) were instrumented using rotary files and thereafter were split longitudinally. Following preparation of a standardized groove in the apical region of one root half, the roots were randomly divided into two groups according to the intracanal medicaments placed into the grooves: (1) CH and (2) TAP. The roots were reassembled, and the specimens were further assigned into four groups (n = 10/group) defined by the final irrigation solution (EDTA and phytic acid) and irrigation technique (needle irrigation and LAI) used for removal of the medicaments. The data were analyzed statistically using Kruskal-Wallis and Mann-Whitney U tests.

RESULTS

For both EDTA and phytic acid, LAI was more efficient than needle irrigation in removing both CH and TAP (p < 0.05), but none of the tested techniques completely removed CH. Irrespective of the tested irrigation solutions and techniques, significantly less TAP remained in canals (p = 0.0001), with TAP being completely removed by LAI. Irrigation with phytic acid showed better removal efficacy than EDTA in the absence of statistical significance.

CONCLUSIONS

Er,Cr:YSGG LAI of EDTA and phytic acid completely removed TAP and effectively reduced CH on root dentin.

Effect of methods of evaluation on sealing ability of mineral trioxide aggregate apical plug

Aim:

The purpose of the study was to evaluate and compare the sealing ability of mineral trioxide aggregate (MTA) with three different methods.

Materials and Methods:

Forty single canal teeth were decoronated, and root canals were enlarged to simulate immature apex. The samples were randomly divided into Group M_D = MTA-angelus mixed with distilled water and Group M_C = MTA-angelus mixed with 2% chlorhexidine, and apical seal was recorded with glucose penetration method, fluid filtration method, and dye penetration methods and compared.

Results:

The three methods of evaluation resulted differently. The glucose penetration method showed that M_D sealed better than M_C, but difference was statistically insignificant (P > 0.05). The fluid filtration method resulted that Group M_C was statistically insignificant superior to Group M_D (P > 0.05). The dye penetration method showed that Group M_C sealed statistically better than Group M_D.

Conclusion:

No correlation was found among the results obtained with the three methods of evaluation. Addition of chlorhexidine enhanced the sealing ability of MTA according to the fluid filtration test and dye leakage while according to the glucose penetration test, chlorhexidine did not enhance the sealing ability of MTA. This study showed that relying on the results of apical sealing by only method can be misleading.

Effectiveness of four different techniques in removing intracanal medicament from the root canals: An in vitro study

Aim:

To evaluate the effectiveness of different techniques in removing calcium hydroxide (Ca(OH)₂) from the root canal.

Materials and Methods:

Twenty-four freshly extracted mandibular premolars were instrumented using ProTaper rotary instruments. The teeth were longitudinally split into two halves, cleaned of debris. The two halves were then reassembled and filled with Ca(OH)₂ and were divided into four groups. In Group I, the teeth were irrigated with 5 mL of 2.5% sodium hypochlorite (NaOCl) and 5 mL of 17% of ethylenediaminetetraacetic acid. In Group II, the teeth were irrigated with 5 mL of 2.5% NaOCl and a rotary ProTaper F3 instrument was used. In Group III, the teeth were irrigated with 5 mL of 2.5% NaOCl and agitated using an ultrasonic unit. In Group IV, the teeth were irrigated with 5 mL of 2.5% NaOCl and a CanalBrush was used to remove Ca(OH)₂. The roots were disassembled, and photographs were taken. The amount of residual Ca(OH)₂ was calculated using an image analysis software as a percentage of the total canal surface area. The data were analyzed using one-way analysis of variance and post-hoc Tukey test.

Results:

CanalBrush and ultrasonic techniques showed significantly less residual Ca(OH)₂ than irrigants and rotary techniques. There was no significant difference between the rotary and irrigant techniques.

Conclusion:

None of the techniques used were completely able to remove Ca(OH)₂ from the root canals. But the CanalBrush and ultrasonic techniques were significantly better than the rotary instrument and irrigant groups.

A titration model for evaluating calcium hydroxide removal techniques

Objective

Calcium hydroxide (Ca(OH)₂) has been used in endodontics as an intracanal medicament due to its antimicrobial effects and its ability to inactivate bacterial endotoxin. The inability to totally remove this intracanal medicament from the root canal system, however, may interfere with the setting of eugenol-based sealers or inhibit bonding of resin to dentin, thus presenting clinical challenges with endodontic treatment. This study used a chemical titration method to measure residual Ca(OH)₂ left after different endodontic irrigation methods.

Material and Methods

Eighty-six human canine roots were prepared for obturation. Thirty teeth were filled with known but different amounts of Ca(OH)₂ for 7 days, which were dissolved out and titrated to quantitate the residual Ca(OH)₂ recovered from each root to produce a standard curve. Forty-eight of the remaining teeth were filled with equal amounts of Ca(OH)₂ followed by gross Ca(OH)₂ removal using hand files and randomized treatment of either: 1) Syringe irrigation; 2) Syringe irrigation with use of an apical file; 3) Syringe irrigation with added 30 s of passive ultrasonic irrigation (PUI), or 4) Syringe irrigation with apical file and PUI (n=12/group). Residual Ca(OH)₂ was dissolved with glycerin and titrated to measure residual Ca(OH)₂ left in the root.

Results

No method completely removed all residual Ca(OH)₂. The addition of 30 s PUI with or without apical file use removed Ca(OH)₂ significantly better than irrigation alone.

Conclusions

This technique allowed quantification of residual Ca(OH)₂. The use of PUI (with or without apical file) resulted in significantly lower Ca(OH)₂ residue compared to irrigation alone.

Intra-canal calcium hydroxide removal by two rotary systems: A comparative study

Aim:

The presence of calcium hydroxide (Ca(OH)₂) in the root canal interferes with the apical root canal sealing and may result in periapical lesions in the long run. The present study was aimed to compare the efficacy of two rotary systems of Race and Mtwo in the removal of Ca (OH)₂ aqueous-based from distobuccal canals of human maxillary molars.

Materials and Methods:

A total of 44 distobuccal root canals of human maxillary molars were randomly distributed into two groups of 20 canals each and two control groups. Specimens in each group were instrumented with similar master apical rotary (MAR) and flexible files according to the manufacture's guidelines. The Ca (OH)₂ paste was placed in canals using # 20 lentulo and radiographs were taken from the two dimensions. The roots were incubated for 1 week at 37°C and 100% humidity and Ca (OH)₂ was removed from canals by MAR, afterward. Then, the roots were longitudinally split in halves by diamond disk and chisel without entering the root canals. Photos were taken from the canals’ walls by a stereomicroscope with × 10 magnification. Next, according to a defined scoring system, photos were scored by four endodontists, so that scores 1 and 2 (nonvisible remnants or scattered remnants of Ca(OH)₂) were considered as acceptable and scores 3 and 4 (distinct mass or densely-packed mass of Ca(OH)₂) were regarded as nonacceptable.

Results:

The obtained findings indicated that in coronal, middle, and apical portions of the root canal, 45, 60, and 65% of Mtwo specimens and 40, 50, and 55% of specimens prepared by the Race system acquired an acceptable score (1 and 2), respectively. Moreover, the results showed no significant difference between the two groups (P > 0.05).

Conclusions:

Both Mtwo and Race rotary systems with acceptable removal efficiency (score 1 and 2) were similarly able to remove Ca(OH)₂

Effectiveness of different irrigation protocols on calcium hydroxide removal from simulated immature teeth after apexification

Aim: To evaluate the effectiveness of different irrigation solutions and ultrasonic activation of the irrigation solutions on the removal of calcium hydroxide (Ca(OH)₂) from the simulated immature root canals after apexification.

Materials and methods: One-hundred and one single-rooted teeth were used. The root canals were shaped with ProTaper rotary files up to F5. Simulation of roots with immature apices was carried out using size 4 Unicore drills. An injectable Ca(OH)₂ was injected into each root canal, and packed to the working length. Then, cotton pellets were placed over canal orifices, and apical and coronal parts of the roots were sealed with resin-modified glass ionomer cement, and light cured. Specimens were stored in distilled water for 3 months at 37°C. After 3 months, the temporary coronal seal was removed and the samples were randomly divided into: (a) saline (n = 20), (b) ultrasonic activation of saline (n = 20), (c) sodium hypochlorite (NaOCl) (n = 20), (d) ultrasonic activation of NaOCl (n = 15), (e) chlorhexidine digluconate (CHX) (n = 20) and one positive control group (n = 3) and one negative control group (n = 3). The amount of remaining Ca(OH)₂ on the canal walls was measured under stereomicroscope with 30× magnification. Comparisons between groups were made by the non-parametric Kruskal-Wallis test and Dunn post-test at a significance level of p < 0.05.

Results: There were no significant differences among the saline, ultrasonic activation of saline, NaOCl, ultrasonic activation of NaOCl and CHX (p > 0.05) groups.

Conclusions: Irrigation solutions and ultrasonic activation of the irrigation solutions could not completely remove Ca(OH)₂ from the simulated immature root canals.

Comparison of different irrigation activation regimens and conventional irrigation techniques for the removal of modified triple antibiotic paste from root canals

INTRODUCTION

The aim of this study was to compare the efficacy of irrigation activation regimens and conventional syringe irrigation technique in the removal of modified triple antibiotic paste (mTAP) from root canal walls.

METHODS

Fifty-six extracted human mandibular premolars were prepared using ProTaper rotary files (Dentsply Maillefer, Ballaigues, Switzerland) up to size F4. The root canals were filled with mTAP medicament, and after 21 days, the roots were randomly assigned to 5 groups (n = 10) according to the irrigation regimens used: conventional syringe irrigation (CI), Self-Adjusting File (SAF; ReDent-Nova, Ra'anana, Israel), EndoVac (Discus Dental, Culver City, CA), EndoActivator (Dentsply, Tulsa, OK), and passive ultrasonic irrigation (PUI). In 3 teeth, mTAP was not removed (positive controls), and another 3 teeth were not filled with mTAP (negative controls). The roots were sectioned, and the amount of remaining medicament at each root half (n = 20) was evaluated at 30× magnification using a 4-grade scoring system. Data were evaluated using the Kruskal-Wallis and Mann-Whitney U tests.

RESULTS

There were statistically significant differences among all experimental groups; of which, the CI group was the significantly least efficient in removing mTAP from the root canal (P < .05). At the apical and middle third, the PUI, SAF, EndoVac, and EndoActivator groups removed significantly more mTAP medicament than the CI group (P < .05); however, there were no significant differences between these groups (P > .05). The SAF and PUI showed significantly better performances in removing mTAP from the coronal third (P < .05).

CONCLUSIONS

The use of irrigation activation regimens significantly improves the removal of mTAP from root canals when compared with CI.

Comparative evaluation of fracture resistance of simulated immature teeth restored with glass fiber posts, intracanal composite resin, and experimental dentine posts

Aim. The aim of this study was to compare the fracture resistance of simulated immature teeth restored with gutta-percha, glass fiber posts (GFP), experimental dentine posts (DP) or Intracanal composite Resin (ICR). Materials and Methods. Fifty maxillary canines were decoronated, standardized and enlarged until, number 5 Peeso reamers were allowed to simulate immature teeth. After placement of 5 mm of MTA, the canals were divided into 5 groups and filled as follows: Group 1: AH Plus + gutta-percha, lateral compaction; Group 2: GFP luted with PARACORE dual cure resin; Group 3: DP luted with PARACORE dual cure resin; Group 4: PARACORE dual cure resin. A standardized core was built in all groups except in Group 5. Each of the specimens was tested for fracture resistance by universal testing machine. Results. The mean fracture resistance were 817 ± 27.753, 1164.6 ± 21.624, 994.4 ± 96.8747, 873.8 ± 105.446 and 493.7 ± 6.945 newtons for Groups 1, 2, 3, 4, and 5 respectively. Independent “t” test revealed statistically significant discrepancies, in the fracture resistance among the 4 groups except Group 1 and Group 4 (P < 0.05). Conclusions. This study suggests that GFP and DP may be preferred for additional reinforcement of immature teeth.

Calcium hydroxide dressing residues after different removal techniques affect the accuracy of Root-ZX apex locator

OBJECTIVES

This study compared the ability of several techniques to remove calcium hydroxide (CH) from the root canal and determined the influence of CH residues on the accuracy of the electronic apex locator.

MATERIALS AND METHODS

Root canals of 90 human maxillary lateral incisors with confirmed true working length (TWL) were prepared and filled with CH. The teeth were randomly assigned to one of the experimental groups according to the CH removal technique (n = 14): 0.9% saline; 0.9% saline + master apical file (MAF); 17% ethylenediamine tetraacetic acid (EDTA); 17% EDTA + MAF; 5.25% sodium hypochlorite (NaOCl); 5.25% NaOCl + MAF. Six teeth were used as negative control. After CH removal, the electronic working length was measured using Root-ZX (Morita Corp.) and compared with TWL to evaluate Root-ZX accuracy. All specimens were sectioned longitudinally, and the area of remaining CH (CH) and total canal area were measured using imaging software.

RESULTS

The EDTA + MAF and NaOCl + MAF groups showed better CH removal than other groups (p < 0.05). Root-ZX reliability to prevent overestimated working length to be > 85% within a tolerance of ± 1.0 mm (p < 0.05). There was strong negative correlation between amount of CH residues and EAL accuracy (r = -0.800 for ± 0.5 mm; r = -0.940 for ± 1.0 mm).

CONCLUSIONS

The mechanical instrumentation improves the CH removal of irrigation solutions although none of the techniques removed the dressing completely. Residues of CH medication in root canals affected the accuracy of Root-ZX adversely.

Retrievabilty of calcium hydroxide intracanal medicament with Chitosan from root canals: An in vitro CBCT volumetric analysis

AIM

This study compared the amount of aqueous-based and oil-based calcium hydroxide [Ca(OH)2 ] remaining in the canal, after removal with two different chelators 17% EDTA and 0.2% Chitosan in combination with ultrasonic agitation.

MATERIALS AND METHODS

Cleaning and shaping of root canals of 28 mandibular premolar was done and canals were filled either with Metapex or Ca(OH)2 mixed with distilled water. Volumetric analysis was performed utilizing cone beam-computed tomography (CBCT) after 7 days of incubation. Ca(OH)2 was removed using either 17% EDTA or 0.2% Chitosan in combination with ultrasonic agitation. Volumetric analysis was repeated and percentage difference was calculated and statistically analysed using Kruskal-Wallis and Mann-Whitney U test.

RESULTS

Both the chelators failed to remove aqueous-based as well as oil-based Ca(OH)2 completely from the root canal. Aqueous-based Ca(OH)2 was easier to be removed than oil-based Ca(OH)2. 0.2% Chitosan was significantly more effective for removal of oil-based Ca(OH)2 (P < 0.01) while both 17% EDTA and 0.2% Chitosan were equally effective in removing aqueous-based Ca(OH)2 .

CONCLUSION

Combination of 0.2% Chitosan and ultrasonic agitation results in lower amount of Ca(OH)2 remnants than 17% EDTA irrespective of type of vehicle present in the mix.

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.

Nonsurgical management of large periapical lesion in mature and immature teeth using different calcium hydroxide formulations: case series

This case series evaluates the effectiveness of different calcium hydroxide formulations with various vehicles in management of large periapical lesion in mature and immature teeth. This will help clinicians to make informed judgments about which formulations of calcium hydroxide should be used for specific endodontic procedures.

Comparison of calcium hydroxide removal by self-adjusting file, EndoVac, and CanalBrush agitation techniques: An in vitro study

Objectives:

This study comparatively evaluated the efficacy of self-adjusting file (SAF), Endovac, and CanalBrush irrigant agitation protocols in removing calcium hydroxide (Ca(OH)₂) from the root canals.

Materials and Methods:

Sixty extracted human mandibular canine teeth were instrumented with ProTaper rotary instruments to size #40 and dressed with Ca(OH)₂. The roots were randomly assigned to four groups according to irrigant agitation protocol used (n = 15). In Group 1: Conventional syringe irrigation (no activation, control); Group 2: Rotary brush agitation (CanalBrush); Group 3: Apical negative pressure irrigation (EndoVac system); and Group 4: Sonic agitation (SAF) were used. Scanning electron microscopic (SEM) evaluation was done for assessment of Ca(OH)₂ removal in the coronal and apical thirds. Statistical analysis was performed by Wilcoxon and Kruskal-Wallis tests.

Results:

There were statistically significant differences among the groups (P = 0.218). A statistically significant difference was seen between the test groups in Ca(OH)₂ removal from the apical third of the canal (P < 0.05). In the coronal third, there was no difference between the groups (P > 0.05). The most efficient Ca(OH)₂ removal in apical third was recorded in Group 3 (EndoVac) and Group 4 (SAF) (P < 0.05). In Group 4 (sonic agitation), there was no significantly difference between Ca(OH)₂ removal in coronal and apical thirds.

Conclusions:

SAF and EndoVac showed significantly better performance than CanalBrush and conventional syringe irrigation in removing Ca(OH)₂ from apical third of the root canals.