Removal efficacy of various calcium hydroxide/chlorhexidine medicaments from the root canal

The effect of different irrigation activation methods on the penetration of the irrigation solution into the dentinal tubules in teeth with calcium hydroxide applied and oval-shaped canals: Confocal laser scanning microscope analysis

This study aimed to evaluate the efficacy of different irrigation techniques including standard needle irrigation (SNI), passive ultrasonic irrigation (PUI), EndoActivator (EA), XP-Endo Finisher (XPF), photon-induced photoacoustic streaming (PIPS), and shock wave enhanced emission photo-acoustic streaming (SWEEPS) systems on the penetration of irrigation solutions into dentinal tubules in teeth with calcium hydroxide (CH) applied and oval-shaped canals by confocal laser scanning microscope (CLSM). Ninety mandibular incisor teeth with oval-shaped canals were included in this study. After the preparation of teeth using Resiproc Blue R25 (VDW, Munich, Germany) canals were filled with a paste based on CH. The teeth were stored in 100% humidity at a temperature of 37°C for 14 days. According to the irrigation activation systems, the teeth were divided into six groups (n = 15); SNI, PUI, EA, XPF, PIPS, and SWEEPS. In each group, 3 irrigation/activation cycles of 20 s of irrigation and 20 s of activation were performed with the relevant activation method. The root canals were filled with fluorescein sodium (Sigma, Alldrich Co., St. Louis, MO, USA) and activated with the relevant activation method for 30 s. Specimens were sectioned horizontally to 1 ± 0.1 mm at 2, 5, and 8 mm from the apex and then examined under the CLSM. Maximum penetration depth, maximum penetration area and penetration percentage were measured by using Image J software. Data were analyzed using a two-way analysis of variance (ANOVA) and posthoc Tukey tests (p = .05). No difference was found between the activation systems in terms of maximum penetration depth and maximum penetration area of irrigation solutions in the apical section (p > .05). The penetration percentage of irrigation solutions was higher in PUI and PIPS compared with EA and XPF at the apical section (p < .05). No difference was found between SNI, PUI, PIPS, and SWEEPS in terms of the penetration percentage of irrigation solutions in all sections (p > .05). The penetration percentage of irrigation solutions was higher in the middle and coronal sections compared to the apical section in EA and XPF (p < .05). Tubule penetration of irrigation solutions in SNI was similar between sections. The Tubule penetration area of irrigation solutions in PUI, EA, XPF, PIPS, and SWEEPS was lower in the apical section than in the middle and coronal sections. RESEARCH HIGHLIGHTS: The tubule penetration depth and area of the irrigation solutions were similar between the activation systems tested in the apical sections. The Tubule penetration area of irrigation solutions in middle and coronal sections was higher in PUI and PIPS than in SNI.

The efficacy of three passive ultrasonic irrigation systems on intracanal medicament removal in a novel standardised three-dimensionally printed model

This study compared the efficacy of several passive ultrasonic irrigation (PUI) systems in removing intracanal medicament using 3-dimensionally printed root canal model assembled with dentin specimen. After the placement of the model in the agar container (37°C), the intracanal medicament was removed using three different PUI instruments including CK file, Irrisafe and Endosonic Blue. Then, the area coated by the medicament and the volumetric percentage of the remaining medicament was measured. Irrisafe and Endosonic Blue showed higher removal efficacy than CK and the control regarding both the coated area and remaining volume (p < 0.05). CK showed the lowest efficacy among the tested PUI systems (p > 0.05). Notably, Endosonic Blue group showed the smallest coated area among the tested groups (p < 0.05). Conclusively, PUI systems made of nickel-titanium alloy with small dimensions, such as Endosonic Blue, have advantages for the removal of intracanal medicaments from curved root canals.

Influence of access cavity design on calcium hydroxide removal using different cleaning protocols: a confocal laser scanning microscopy study

Objectives

The purpose of this study was to evaluate the influence of endodontic access cavities design on the removal of calcium hydroxide medication of the apical third of mandibular incisor root canal walls and dentinal tubules with different cleaning protocols: EDDY sonic activation, Er,Cr:YSGG laser-activated irrigation, or conventional irrigation with IrriFlex.

Materials and Methods

Seventy-eight extracted human mandibular incisors were assigned to 6 experimental groups (n = 13) according to the endodontic access cavity and cleaning protocol for calcium hydroxide removal: traditional access cavity (TradAC)/EDDY; ultraconservative access cavity performed in the incisal edge (UltraAC.Inc)/EDDY; TradAC/Er,Cr:YSGG; UltraAC.Inc/Er,Cr:YSGG; TradAC/IrriFlex; or UltraAC.Inc/IrriFlex. Confocal laser scanning microscopy images were used to measure the non-penetration percentage, maximum residual calcium hydroxide penetration depth, and penetration area at 2 and 4 mm from the apex. Data were statistically analyzed using Shapiro-Wilk and WRS2 package for 2-way comparison of non-normally distributed parameters (depth of penetration, area of penetration, and percentage of non-penetration) according to cavity and cleaning protocol with the significance level set at 5%.

Results

The effect of cavity and cleaning protocol interactions on penetration depth, penetration area and non-penetration percentage was not found statistically significant at 2 and 4 mm levels (p > 0.05).

Conclusions

The present study demonstrated that TradAC or UltraAC.Inc preparations with different cleaning protocols in extracted mandibular incisors did not influence the remaining calcium hydroxide at 2 and 4 mm from the apex.

Antimicrobial Efficacy of Two Different Calcium Hydroxide Endodontic Dressings on the Eradication of Enterococcus faecalis in Single-Rooted Canals: An In Vitro Study

INTRODUCTION

Bacterial pulp infections are considered the most common cause of endodontic treatment failure. Enterococcus faecalis was isolated from most cases of failure of endodontic treatment. Therefore, using the appropriate intra-canal dressing is essential for successful treatment. The improved formula used in calcium hydroxide PLUS points ensures more calcium hydroxide is released over a longer period and more space to release calcium hydration. This in vitro research aimed to evaluate the differences in the efficacy between Ca(OH)₂ paste and PLUS points as an endodontic dressing in eradicating E. faecalis growth inside infected single-rooted canals.

MATERIALS AND METHODS

Thirty mandibular first premolars with single canals were extracted for orthodontic reasons and were prepared after cutting their crowns to standardize the length of the roots to 17 mm, root preparation, and isolating E. faecalis. The infected sample root canals were contaminated with the prepared bacterial suspension, and the sample was incubated in the incubator under air conditions at 37°C for seven days, counting the bacteria colonies. Then, the bacterial units were counted before applying the drug, applying Ca(OH)₂ paste in the first group and Ca(OH)₂ PLUS points in the second group. The bacterial units were counted, and the number of bacteria was compared between the two substances applied to the samples, measuring the intracanal dressings' effectiveness. Wilcoxon signed-rank tests were used to detect significant differences.  Results: The results showed a statistically significant difference in the bacterial count of E. faecalis before and after applying the dressing of Ca(OH)₂ paste from a mean of 11.89 to a mean of 3.18 (p=0.003) and no statistical difference in applying Ca(OH)₂ PLUS points from mean 11.98 to mean 10.50 (p>0.05).

CONCLUSION

Within the limits of the current in vitro study, the Ca(OH)₂ paste cones were more effective than Ca(OH)₂ PLUS points in eradicating E. faecalis growth inside the infected single-rooted canals.

Farklı irrigasyon tekniklerinin kalsiyum hidroksit uzaklaştırma etkinliğinin Bilgisayarlı Sıvı Filtrasyon methodu kullanılarak mikrosızıntılarının değerlendirilmesi

Aim: To compare the efficiency of sonic irrigation, passive ultrasonic irrigation, and conventional syringe irrigation (CI) in removing pure and injectable calcium hydroxide (CH) from the root canals of mandibular second premolars by measuring the probable microleakage of residual CH particles in root canal obturation using computerized liquid filtration (CLF). Materials and Methods: Eighty instrumented mandibular second premolars were categorized into three experimental groups (n = 20 each) based on the irrigation method used for removing CH and a control group (n = 20) in which CH was not used. Each experimental group was divided into two equal groups (pure and injectable CH). After 1 week, CH was removed from the root canals, and the teeth were obturated. CLF measurements were performed 1 week after obturation. Nonparametric variables between two groups were compared using the Mann-Whitney U test, and the Kruskal-Wallis test was used to compare more than two groups. The significance level was set at p &lt; 0.05. Results: All experimental groups showed higher leakage values than the control group. The highest leakage values were evident in the CI group, and the lowest leakage values were found in the sonic (EDDY) irrigation group. No significant differences were detected among the different forms of CH. Conclusions: None of the analyzed techniques could completely remove CH from root canals, resulting in higher leakage values. Sonic irrigation with EDDY was the best in removing CH from root canals.

Endodontic cement penetration after removal of calcium hydroxide dressing using XP-endo finisher

We aimed to evaluate the penetration of endodontic cement following the removal of calcium hydroxide (Ca(OH)2) dressing using the XP-endo Finisher in association with different irrigating solutions. Sixty premolars were instrumented and applied with a Ca(OH)2 dressing. To remove Ca(OH)2, the teeth were divided into six groups, each with a different volume of sodium hypochlorite (NaOCl) and ethylenediaminetetraacetic acid (EDTA), as well as solution stirring time with XP-endo Finisher (0, 30, and 60 sec). Root canals were filled using the lateral condensation technique. Fluorescein dye was added to the cement for microscopic laser scanning analysis. In the generated images, linear measurements were taken in micrometers, and their averages were calculated. To analyze the perimeter penetration ratio of the cement, the total perimeter of the canal and the segment of the total perimeter of the canal where the endodontic cement penetrated into the dentinal tubules were measured in micrometers. We found that using an XP-endo Finisher in irrigation was more effective than using a needle and syringe during the extension and penetration of endodontic cement. Shaking with XP-endo Finisher with 17% EDTA increased the extent and perimeter of the penetration of the endodontic cement into the dentinal tubules. However, using the XP-endo Finisher with EDTA only was more efficient than using the instrument interchangeably in NaOCl and EDTA. Although XP-endo Finisher contributes to the removal of Ca(OH)2, none of the protocols or instruments used removed all Ca(OH)2 from the root system.

Retrievability of Odontopaste and Metapex With 17% Ethylenediaminetetraacetic Acid and 10% Maleic Acid From Root Canals: An Invitro Study

Aim

To evaluate the efficacy of 10% maleic acid in comparison with 17% ethylenediaminetetraacetic acid (EDTA) in the removal of intracanal medicaments from the root canal system.

Materials and methods

Forty-eight extracted single-rooted mandibular premolars were decoronated to standardize the length of 14 mm. Chemomechanical preparation was done using the crown-down technique with Protaper files (Dentsply‑Maillefer, Ballaigues, Switzerland) till F4, followed by irrigation with 2 ml of 5.25% sodium hypochlorite (NaOCl) after each instrument, and 5 ml of 17% EDTA was used as the final irrigating agent.

Metapex (Meta Dental Corp. Ltd., Elmhurst, NY, USA) and Odontopaste (Australian Dental Manufacturing, Kenmore Hills, Qld, Australia) were the two intracanal medicaments that were used in this study.

Total samples were divided into two groups based on the intracanal medicament that was placed in the canal. In group 1, Metapex was injected into the root canal until the material extruded through the apex. In group 2, Odontopaste was placed into the canal until the material extruded through the root apex. Cleaning off the excess medicament was done with a moist cotton pellet. After temporary sealing with a cotton pellet and Cavit, all the samples were stored at 37 ºC and 100% relative humidity for a period of seven days. The teeth in each group were further randomly divided into three subgroups on the basis of the irrigant used for retrieval of medicament. In groups 1A and 2A, 1ml of 17% EDTA was used; in groups 1B and 2B, 1ml of 10% maleic acid was used; in groups 1C and 2C, 1ml of 0.9% saline was used. Sonic agitation for 1 minute, followed by a final rinse of 1 ml distilled water, was used in all the groups.

After the intracanal medicament was removed from the canal, the roots were longitudinally sectioned using a diamond disk (Bego, Berman, Germany). The residual medicament on each section was evaluated under a stereomicroscope (×30; Medilux, MDL-DS4-BI, Biosystems, Curitiba, PR, Brazil). The data were analyzed using SPSS version 23.0 software (IBM Corp., Armonk, NY). Kruskal-Wallis ANOVA and Mann-Whitney U test (post hoc) were applied for intergroup comparisons. A Wilcoxon signed-rank test was applied for intragroup comparisons.

Results

Both the chelators, 17% EDTA and 10% maleic acid, removed the Odontopaste significantly better than Metapex. However, 17% EDTA was more effective in the removal of Odontopaste. 10% Maleic acid showed better results in the removal of Metapex than 17% EDTA.

Conclusion

None of the chelating agents was able to totally retrieve the intracanal medicaments. When compared to Metapex, Odontopaste showed significantly better retrievability from the root canal with both 17% EDTA and 10% Maleic acid, whereas the retrievability of Metapex was significantly better with 10% Maleic acid in comparison to 17% EDTA.

Efficacy of Laser-Activated Irrigation and Conventional Techniques in Calcium Hydroxide Removal from Simulated Internal Resorption Cavities: Micro-CT Study

Objective: This study aimed to evaluate the effectiveness of different irrigant-activation techniques for eliminating calcium hydroxide from an internal root canal resorption cavity by using microcomputed tomography (micro-CT). Background: Several techniques and irrigants are inadequate for the complete removal of calcium hydroxide from an internal root resorption cavity. Recently, a few studies have investigated the effectiveness of various methods, but there has been no micro-CT study that compares the effectiveness of photon-induced photoacoustic streaming (PIPS) and shock wave enhanced emission photoacoustic streaming (SWEEPS) techniques. Methods: Seventy single-canal mandibular premolar teeth were selected and divided into seven groups (n = 10) according to the techniques to be used: syringe irrigation (SI), passive ultrasonic irrigation (PUI), EndoActivator (EA), XP-Endo finisher file (XP), Er,Cr:YSGG laser-activated irrigation, PIPS, and SWEEPS. The root canals were instrumented using a rotary system and divided vertically. Internal resorption cavities were created and standardized through diamond burs. Calcium hydroxide was placed into the root canal space. All specimens were evaluated using micro-CT in two different periods. The initial and residual calcium hydroxide volumes in the simulated cavities were calculated. Data were analyzed using a Kruskal-Wallis H test. Results: SWEEPS and PIPS were significantly more effective than EA, Er,Cr:YSGG, PUI, XP, and SI (p < 0.05). There was no significant difference between the SWEEPS and PIPS groups (p > 0.05). SI and XP showed the least effective activity (p < 0.05). Conclusions: The SWEEPS and PIPS techniques were superior to the EA, Er,Cr:YSGG, PUI, XP, and SI techniques. None of the techniques used entirely removed the calcium hydroxide from the resorption cavities.

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.

Effect of various calcium hydroxide removal protocols on the dislodgement resistance of biodentine in an experimental apexification model

Background/purpose

Residual calcium hydroxide (CH) in the root canal dentine walls may influence the adhesion of tricalcium silicate-based materials. The aim of this study is to evaluate the effect of various CH removal protocols on the dislodgement resistance of biodentine from simulated immature root canals in an experimental apexification model.

Materials and methods

CH was applied to 120 simulated immature root canals. The samples were divided into 12 experimental groups (n = 10) according to the applied irrigation protocols used for the removal of CH: Group 1: Sodium hypochlorite (NaOCl), Conventional needle irrigation (CNI); Group 2: NaOCl, EndoActivator; Group 3: NaOCl, XP-endo Finisher; Group 4: NaOCl- Ethylenediaminetetraacetic acid (EDTA), CNI; Group 5: NaOCl-EDTA, EndoActivator; Group 6: NaOCl-EDTA, XP-Endo Finisher; Group 7: NaOCl+etidronic acid (HEBP), CNI; Group 8: NaOCl+HEBP, EndoActivator; Group 9: NaOCl+HEBP, XP-endo Finisher; Group 10: NaOCl- Peracetic acid (PAA), CNI; Group 11: NaOCl-PAA, EndoActivator; Group 12: NaOCl-PAA, XP-endo Finisher; Control Group: CH was not applied. Biodentine was placed at the apical thirds of 130 immature root canals. Vertical loading was applied to biodentine fillings inside the dentin discs. Maximum force to dislodge the material was statistically analyzed with ANOVA.

Results

The control, NaOCl+HEBP (CNI, EndoActivator, XP-endo Finisher) and NaOCl-PAA (EndoActivator, XP-endo Finisher) groups exhibited the lowest dislodgement resistance values (p < 0.001). When used CNI, irrigation with NaOCl+HEBP resulted in lower resistance to dislodgement of biodentine compared to NaOCl, and NaOCl-EDTA (p < 0.001).

Conclusion

Adhesion of apical barrier materials to root canal dentine can be influenced by the irrigation protocols used for CH removal.

Final Endodontic Irrigation with 70% Ethanol Enhanced Calcium Hydroxide Removal from the Apical Third

INTRODUCTION

The purpose of this study was to evaluate the cleanliness of root canal walls and dentinal tubules after attempting to remove the calcium hydroxide dressing with different irrigant solutions and the use of nonactivated irrigation or passive ultrasonic irrigation (PUI).

METHODS

After root canal instrumentation, 80 single-rooted teeth were filled with calcium hydroxide mixed with propylene glycol and 0.1% rhodamine B dye and inserted into canals with a Lentulo spiral. The calcium hydroxide dressing was initially removed with 10 mL saline solution and reinstrumentation with the master apical file. Then, the samples were randomly assigned into 8 experimental groups (n = 10) according to the irrigant solution with or without PUI: 2.5% sodium hypochlorite, 17% ethylenediaminetetraacetic acid + 1.25% sodium lauryl ether sulfate (EDTA-T), 37% phosphoric acid, or 70% ethanol. A final flush with 5 mL saline solution was performed. The percentage of clean root canal walls and the depth of clean dentinal tubules were measured with images of confocal laser scanning microscopy. The groups were compared using the 2-way analysis of variance test with the Bonferroni post hoc test for depth analysis and the Kruskal-Wallis with Dunn post hoc test for the perimeter analysis.

RESULTS

Irrigation with 70% ethanol presented a significantly higher percentage of clean root canal walls and a higher depth of clean dentinal tubules when compared with irrigation with 2.5% sodium hypochlorite and 17% EDTA-T for both irrigation methods (P < .05). No differences were observed between nonactivated irrigation or PUI protocols (P > .05).

CONCLUSIONS

Seventy percent ethanol enhanced calcium hydroxide removal from the apical root third compared with 2.5% sodium hypochlorite or 17% EDTA-T.

Effect of Various Irrigating Devices on the Removal of Two Different Forms of Calcium Hydroxide from Internal Resorption Cavities

The present study aimed to investigate the efficiency of passive ultrasonic irrigation (PUI), EndoActivator (EA), standard needle irrigation (SNI), and XP-endo Finisher files in removing pure calcium hydroxide (pCH) and injectable CH from in vitro root resorption cavities. Using a rotary system, the root canals of 116 extracted single rooted teeth were prepared. Imitated internal resorption cavities were then created in root halves. The specimens were divided into two groups according to the form of CH (n = 58): (I) pCH; (II) injectable CH. The teeth of each group were randomly divided into six subgroups: negative control (n = 5), positive control (n = 5), PUI (n = 12), XP-endo Finisher (n = 12), EA (n = 12), and SNI (n = 12). The root canals were irrigated using NaOCl and EDTA and split longitudinally, and both halves were evaluated with a stereomicroscope. Kruskal–Wallis and Mann–Whitney U tests were used to analyze data. The present results revealed that PUI completely removed pCH in 79% and injectable CH in 70.8% of the internal resorption cavities which was significantly higher than other methods (p < 0.05). There was no statically significant difference between different forms of CH in terms of CH removal (p=0.918). The PUI technique was observed as the most efficient method of P-CH and injectable CH removal from a replicated internal resorption cavity. Finally, according to the findings, different forms of CH were comparable in terms of CH removal.

Antimicrobial Activity of Methanolic Extracts of Myrtus Communis L. and Eucalyptus Galbie and their Combination with Calcium Hydroxide Powder against Enterococcus Faecalis

Statement of the Problem:

The goal of endodontic therapy is the reduction or elimination of microorganisms from the root canal system. The use of intracanal medicament between treatment appointments is recommended in order to eliminate any remainang microorganisms in the pulp space.

Purpose:

The aim of the present study was to investigate the antimicrobial activity of methanolic extracts of Myrtus communis L. and Eucalyptus galbie, their combination with calcium hydroxide powder; combination of calcium hydroxide powder with water, and ready-to-use calcium hydroxide paste with iodoform; against Enterococcus faecalis.

Materials and Method:

In this experimental study, after gathering the plants, their methanolic extracts were obtained by masceration method. The diameters of inhibition zone of all mentioned materials were determined by agar diffusion test. Minimum inhibitory concentration (MIC), minimum bactericidal concentration (MBC); and anti biofilm effect of the materials that showed antibacterial effect in agar diffusion test, were then evaluated by tube dilution test, and microtiter plate assay followed by colorimetric crystal violet methods, respectively.

Results:

After 48 hours, both herbal extracts showed antimicrobial effect. However, combination of calcium hydroxide with extracts produced no zone of inhibition. The mean inhibition zone of Eucalyptus extract was more than that of Myrtus. However, the results of ANOVA test, showed that there was no significant difference between the antibacterial effect of Eucalyptus galbie, Myrtus communis L. and positive control (Cefoxitin) (p Value= 0.987). The MIC for both extracts were 12.5 mg/ml. MBC evaluation of the two methanolic extracts showed no bactericidal effect on Enterococcus faecalis. Based on ELISA analysis, biofilm formation in response to different sub-MIC concentrations of both extracts was scored as weak to moderate.

Conclusion:

The methanolic extracts of Eucalyptus galbie and Myrtus communis L. in combination with calcium hydroxide powder were not able to eliminate Enterococcus faecalis within 48 hours.

Number of Dental Stem Cells on Root Canal Dentin after Application of Triple Antibiotic Paste or Calcium Hydroxide: An In Vitro Study

OBJECTIVE

The aim of this study was to evaluate the viability of stem cells from exfoliated and deciduous teeth (SHED) on dentin surface treated with triple antibiotic paste or calcium hydroxide.

MATERIALS AND METHODS

Nine single-rooted extracted premolars were prepared appropriately and divided into three groups. In group A, the root canals were left empty, a triple antibiotic paste was placed in the root canals of group B, and calcium hydroxide was placed in the root canals of group C. After 1 week, the intracanal medicaments were removed, and stem cells were seeded on the treated surface of the specimens for 1 more week. The cells were stained and then observed under confocal microscope over the entire surface of each test material. Counting of the cells was made by Image J (3D) software, as well as manually.

STATISTICAL ANALYSIS

To investigate any statistically significant differences between the experimental groups, statistical tests including Kruskal-Wallis and Mann-Whitney U-test were performed. Significance level was set to P < 0.05, and all analyses were performed with SPSS IBM program, v. 21.

RESULTS

Groups B and C showed statistically significantly higher number of cells compared to Group A, whereas cells developed in a substrate of calcium hydroxide residues appeared in majority with distinct cores and widened unlike other groups.

CONCLUSIONS

The effect of calcium hydroxide manifested better results regarding the number of stems cells on root canal surfaces.

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.

Effectiveness of various irrigation protocols for the removal of calcium hydroxide from artificial standardized grooves

Objective

The aim of this study was to investigate the ability of laser-activated irrigation (LAI), XP-endo Finisher, CanalBrush, Vibringe, passive ultrasonic irrigation (PUI), and conventional syringe irrigation systems on the removal of calcium hydroxide (CH) from simulated root canal irregularities.

Material and Methods

The root canals of one hundred and five extracted single-rooted teeth were instrumented using Reciproc rotary files up to size R40. The teeth were split longitudinally. Two of the three standard grooves were created in the coronal and apical section of one segment, and another in the middle part of the second segment. The standardized grooves were filled with CH and the root halves were reassembled. After 14 days, the specimens were randomly divided into 7 experimental groups (n=15/group). CH was removed as follows: Group 1: beveled needle irrigation; Group 2: double side-vented needle irrigation; Group 3: CanalBrush; Group 4: XP-endo Finisher; Group 5: Vibringe; Group 6: PUI; Group 7: LAI. The amount of remaining CH in the grooves was scored under a stereomicroscope at 20× magnification. Statistical evaluation was performed using Kruskal–Wallis and Bonferroni-Correction Mann–Whitney U tests.

Results

Groups 1 and 2 were the least efficient in eliminating CH from the grooves. Groups 6 and 7 eliminated more CH than the other protocols; however, no significant differences were found between these two groups (P>.05).

Conclusions

Nevertheless, none of the investigated protocols were able to completely remove all CH from all three root regions. LAI and PUI showed less residual CH than the other protocols from artificial grooves.

Comparison of different irrigation and agitation methods for the removal of two types of calcium hydroxide medicaments from the root canal wall: an in-vitro study

Background and aim

Comparison of different irrigation and agitation methods for the removal of two types of calcium hydroxide medicaments from the root canal walls.

Methods

Fifty extracted single rooted teeth were selected for this study. After decoronation, the root canals of these teeth were prepared to the size F3 (30 no.) using rotary ProTaper file system. These samples were randomly divided into four groups. Group 1 (n=20) were filled completely with water based calcium hydroxide (CH), Group 2 (n=20) were filled with oil based CH using lentulo spiral, Group 3 (n=5) - the positive control group received the CH as intracanal medication, but no subsequent removal, Group 4 (n=5) - the negative control did not receive CH placement. Further on, Group 1 and Group 2 were divided into four sub-groups (n=5). In sub-group A we performed conventional syringe irrigation with side-vented needle sub-group B) manual dynamic agitation, sub-group C sonic agitation using endoactivator, sub-group D passive ultrasonic irrigation (PUI). Roots were split longitudinally into mesial and distal halves. Digital images of the root canal walls were acquired by a Dental Operating Microscope (DOM) and assessed by using a scoring criteria at different thirds (coronal, middle and apical) of the root canal as follows: score 1, score 2, score 3, and score 4. Data were analyzed applying one-way analysis of variance (ANOVA) and Tukey’s multiple comparison tests at a 95% confidence interval (P < 0.05).

Results

Statistically significant differences were not found between the experimental groups and the negative group in any one third of the root canal (P>0.05). However, a difference did exist between the experimental groups and the positive control group (P<0.05). None of the experimental groups totally removed CH substances from root canal walls.

Conclusion

Among all experimental groups, removal of CH was best achieved by sonic agitation using endoactivator followed by passive ultrasonic irrigation (PUI), manual dynamic agitation and conventional syringe irrigation with side-vented needle.

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.

Removal of calcium hydroxide from Weine Type II systems using photon-induced photoacoustic streaming, passive ultrasonic, and needle irrigation: a microcomputed tomography study

Objective

This study compared the effectiveness of Er:YAG laser-activated irrigation (PIPS), passive ultrasonic irrigation (PUI) with EndoUltra and standard needle irrigation (SNI) in the removal of calcium hydroxide [Ca(OH)2] from the mesial roots of Weine Type II mandibular molars.

Material and Methods

Thirty mandibular molars were screened by µCT for the presence of mesial roots with complex intra-canal anatomy and a common apical foramen. The teeth were enlarged to a standardized 25/.06 preparation and filled with Ca(OH)2 paste. Specimens were divided into three groups (n=10) according to the technique used for Ca(OH)2 removal: PIPS, at 15 Hz and 20 mJ using a 9 mm long, 600 µm diameter tip; PUI using a 15/.02 tip; and SNI (30 Ga. side-vented needle). Equal volumes of 8.25% NaOCl and 17% EDTA were used in all groups. µCT was used to measure the initial amount of Ca(OH)2 present and to assess the residual volume of Ca(OH)2 following each irrigation protocol. Data were analyzed using Tukey HSD and Kruskal-Wallis tests (α=5%).

Results

The mean volume of Ca(OH)2 before removal was significantly higher in the coronal third than in the middle and apical third (p<0.001). Ca(OH)2 was similarly removed from the coronal and middle thirds with the three methods used (p>0.05). PIPS (median 0%; IQR: 0-0) showed significant higher Ca(OH)2 removal in the apical third than PUI (median 100%, IQR: 85-100) and SNI (median 47%; IQR: 16-72) (p<0.001).

Conclusions

PIPS laser-activation was more effective for the removal of Ca(OH)2 from mesial roots of mandibular molars with Weine Type II canal configurations than PUI with EndoUltra and SNI.

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.

Comparison of different agitation methods for the removal of calcium hydroxide from the root canal: Scanning electron microscopy study

Aim:

This ex vivo study compared the efficiency of different irrigations systems to remove calcium hydroxide from root canal walls, especially from the apical third by using scanning electron microscopy (SEM).

Materials and Methods:

Eighty-four single-rooted teeth were divided into 4 groups of 20 teeth each, according to different irrigation protocols using a 30-gauge slot-tipped needle, ultrasonic irrigation system, erbium-doped yttrium aluminum garnet laser (Er: YAG) laser, and EndoVac system. The rest 4 teeth were used as control groups (2 positive and 2 negative control groups). After coronal access, all teeth were instrumented by Protaper Next rotary files (Dentsply-Maillefer, Ballaigues, Switzerland) up to size X3, followed an irrigation protocol and filled with pure calcium hydroxide powder mixed with saline. Teeth were stored in an incubator for 7 days, and then, calcium hydroxide was removed using 3 techniques: Manually (Group 1), by ultrasonic irrigation (Group 2), by laser Er: YAG and x-pulse tip (Group 3), and by EndoVac system (Group 4). The teeth of control groups were instrumented as the experimental groups; no removal technique was applied in positive group, whereas in negative one, the root canals were left empty. Teeth were sectioned longitudinally and observed under SEM Results were statistically analyzed with the Kruskal–Wallis Test and Mann–Whitney Test.

Results:

The results showed a significant difference between laser and the other three groups in coronal and middle root third, but no statistic difference in apical third.

Conclusion:

Laser improved the removal of calcium hydroxide in comparison with conventional techniques.

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.

Comparative scanning electron microscopy evaluation of Canal Brushing technique, sonic activation, and master apical file for the removal of triple antibiotic paste from root canal (in vitro study)

Aims:

To compare and evaluate the effectiveness of Canal Brushing technique, sonic activation, and master apical file (MAF) for the removal of triple antibiotic paste (TAP) from root canal using scanning electron microscopy (SEM).

Materials and Methods:

Twenty-two single rooted teeth were instrumented with ProTaper up to the size number F2 and dressed with TAP. TAP was removed with Canal Brush technique (Group I, n: 6), sonic (EndoActivator) (Group II, n: 6), and MAF (Group III, n: 6). Four teeth served as positive (n: 2) and negative (n: 2) controls. The roots were split in the buccolingual direction and prepared for SEM examination (×1000) at coronal, middle, and apical third. Three examiners evaluated the wall cleanliness.

Statistical Analysis:

Statistical analysis was performed by Kruskal–Wallis test and Wilcoxon rank sum test.

Results:

Difference in cleanliness between three groups is statistically significant in cervical region only. Pairwise comparison in cervical region Canal Brush and sonic activation showed more removal of TAP than MAF.

Conclusions:

Canal Brush and sonic activation system showed better result than MAF in the cervical and middle third of canal. In the apical third, none of the techniques showed a better result. None of the techniques showed complete removal of TAP from the canal.

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

Efficacy of Needle, Ultrasonic, and Endoactivator Irrigation and Photon-Induced Photoacoustic Streaming in Removing Calcium Hydroxide from the Main Canal and Isthmus: An In Vitro Micro-Computed Tomography and Scanning Electron Microscopy Study

OBJECTIVE

The aim of this in vitro study was to use high-resolution micro-computed tomography (micro-CT) and scanning electron microscopy (SEM) to compare the efficacy of four irrigation techniques [needle, ultrasonic, EndoActivator, and photon-induced photoacoustic streaming (PIPS)] in removing calcium hydroxide (Ca[OH]2) from the root canal and isthmus of maxillary premolars.

METHODS

Twenty-four maxillary first premolars were selected based on the presence of isthmus regions on micro-CT scans. Root canals were instrumented with an F2 file using ProTaper rotary instruments and filled with Ca(OH)2 paste. Samples were stored at 37°C and 100% humidity for 1 week and randomly divided into four groups (n=6 each), according to irrigation technique. Samples were scanned with micro-CT before instrumentation, after Ca(OH)2 filling, and after irrigation. Ca(OH)2 reduction in the coronal, middle, and apical thirds and in the isthmus were assessed with three-dimensional image analysis. Next, specimens were split longitudinally, and canal walls were examined with SEM for Ca(OH)2 residues. Data were statistically evaluated with the Kruskal-Wallis and Mann-Whitney tests (p=0.05).

RESULTS

The PIPS and ultrasonic groups showed greater Ca(OH)2 reduction in the apical third and higher cleanliness of the isthmus than the EndoActivator and needle irrigation groups (p<0.05). Ca(OH)2 residue scores in the PIPS and ultrasonic groups were significantly lower than those in the EndoActivator and needle groups in all regions of the root canals (p<0.05). There was no significant difference between PIPS and ultrasonic groups (p>0.05), or between EndoActivator and needle groups (p>0.05).

CONCLUSIONS

PIPS and ultrasonic irrigation more effectively removed Ca(OH)2 from the main canal and isthmus in maxillary premolars than did EndoActivator or needle irrigation.

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.

The effect of residual calcium hydroxide on the accuracy of a contemporary electronic apex locator

OBJECTIVE

The aim of this study was to evaluate the effect of residual calcium hydroxide [Ca(OH)2] on the accuracy of an electronic apex locator (EAL).

MATERIALS AND METHODS

Working lengths (WLs) of 56 extracted maxillary incisors were determined initially by two different methods. The first method used the 'APEX' reading of the EAL as a reference point, 0.5 mm was subtracted and recorded as WL0. The second method used the '0.5' reading and the score was recorded as WL0.5 without subtraction. The roots were prepared to WL0 and divided randomly into three experimental groups (n = 16) (1 mm in group A, 2 mm in group B and 4 mm in group C) and a control (n = 8). Specimens in all experimental groups were filled with Ca(OH)2 paste. Following its removal, WLs were re-determined with the same methods.

RESULTS

In group C, pre/post WLs were significantly different (p < 0.05). No significant difference was observed between the other experimental groups and the control group.

CONCLUSION

Accuracy of EAL decreased proportionally with the amount of paste remaining at the ±0.5-mm tolerance level. Ca(OH)2 paste remnants may cause incorrect EAL readings.

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.

Efficacy of ethylene-diamine-tetra-acetic acid associated with chlorhexidine on intracanal medication removal: a scanning electron microscopy study

The aim of this study was to evaluate the effectiveness of 17% ethylene-diamine-tetra-acetic acid (EDTA) used alone or associated with 2% chlorhexidine gel (CHX) on intracanal medications (ICM) removal. Sixty single-rooted human teeth with fully formed apex were selected. The cervical and middle thirds of each canal were prepared with Gates Glidden drills and rotary files. The apical third was shaped with hand files. The specimens were randomly divided into two groups depending on the ICM used after instrumentation: calcium hydroxide Ca(OH)(2) +CHX or Ca(OH)(2) +sterile saline (SS). After seven days, each group was divided into subgroups according to the protocol used for ICM removal: instrumentation and irrigation either with EDTA, CHX+EDTA, or SS (control groups). All specimens were sectioned and processed for observation of the apical thirds by using scanning electron microscopy. Two calibrated evaluators attributed scores to each specimen. The differences between the protocols for ICM removal were analyzed with Kruskal-Wallis and Mann-Whitney U tests. Friedman and Wilcoxon signed rank tests were used for comparison between the score of debris obtained in each root canal third. Remains of Ca(OH)(2) were found in all specimens independently of the protocol and ICM used (P > 0.05). Seventeen percent EDTA showed the best results in removing ICM when used alone (P < 0.05), particularly in those associated with CHX. It was concluded that the chelating agent 17% EDTA significantly improved the removal of ICM when used alone. Furthermore, the type of the vehicle associated with Ca(OH)(2) also plays a role in the ICM removal.

Eficácia da irrigação ultrassônica passiva na remoção de hidróxido de cálcio

INTRODUÇÃO: Remanescentes de Hidróxido de Cálcio [Ca(OH)2] podem interferir na qualidade da obturação endodôntica. OBJETIVO : Avaliar a eficácia da Irrigação Ultrassônica Passiva (IUP) associada à técnica convencional na remoção de medicação intracanal à base de Ca(OH)2. METODOLOGIA: Trinta dentes humanos anteriores monorradiculares foram usados. Os canais radiculares foram preparados com instrumentos manuais tipo K e preenchidos com medicação intracanal à base de Ca(OH)2, contendo PMCC e propilenoglicol. Após sete dias, a pasta de Ca(OH)2 foi removida de todos os canais radiculares com um instrumento manual e irrigação de NaOCl 1% com seringa. Os espécimes foram randomizados em dois grupos (n=12) de acordo com a irrigação final: Irrigação Manual - agitação manual de EDTA 17 % e irrigação de NaOCl 1%; IUP - agitação ultrassônica de NaOCl 1% (três ativações de 20s) seguida da ativação de EDTA 17% por 1 min. O Grupo Controle (n=6) não recebeu medicação intracanal. Todos os espécimes foram clivados e a quantidade de Ca(OH)2 remanescente foi calculada com o auxílio do estereomicroscrópio (20×). Os testes Kruskall-Wallis e Wilcoxon foram utilizados para avaliar a porcentagem de Ca(OH)2 remanescente. RESULTADO: O grupo da IUP apresentou, estatisticamente, as menores porcentagens de Ca(OH)2 remanescente, quando comparado ao grupo da Irrigação Manual, independentemente dos terços analisados (P < 0,05). O terço apical apresentou a maior quantidade de medicação residual, em ambos os grupos (P < 0,05). CONCLUSÃO : A associação da IUP com a técnica convencional demonstrou ser mais eficiente na remoção de medicação intracanal à base de Ca(OH)2 do que a combinação da Irrigação Manual com a técnica convencional.