Efficacy of several techniques for the removal of calcium hydroxide medicament from 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.

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.

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.

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.

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.

Effect of ultrasonic and Nd: Yag laser activation on irrigants on the push-out bond strength of fiber post to the root canal

OBJECTIVE

This in vitro study aimed to compare the efficacy of irrigants using various irrigation activation methods to the push-out bond strengths of fiber post to root canal luted with self-adhesive resin cement (SARC).

METHODOLOGY

Forty-eight decoronated human canines were used. The specimens were divided into four groups corresponding with the post-space irrigation process and were treated as follows: distilled water (DW) (Control) group received 15 mL of DW; sodium hypochlorite (NaOCl)+ethylenediaminetetraacetic acid (EDTA) group was treated with 5 mL of 5.25% NaOCl, 5 mL of 17% EDTA, and 5 mL of DW; passive ultrasonic irrigation (PUI) group was treated with 5 mL of 5.25% NaOCl, 5 mL of 17% EDTA, and 5 mL of DW, and each irrigant was agitated with an ultrasonic file; and laser activated irrigation (LAI) group was treated with 5 mL of 5.25% NaOCl, 5 mL of 17% EDTA, and 5 mL of DW, and each irrigant was irradiated with Nd: YAG laser. Fiber posts were luted with SARC, and a push-out test was performed. Data was analyzed using one-way analysis of variance and Tukey HSD test.

RESULTS

The bond strength values for the groups obtained were as follows: Control (10.04 MPa), NaOCl+EDTA (11.07 MPa), PUI (11.85 MPa), and LAI (11.63 MPa). No statistically significant differences were found among all experimental groups (p>0.05). The coronal (12.66 MPa) and middle (11.63 MPa) root regions indicated a significantly higher bond strength compared with the apical (9.16 MPa) region (p<0.05).

CONCLUSIONS

Irrigant activation methods did not increase the bond strength of fiber post to canal.

Comparison of Residual Triple Antibiotic Paste, Propolis and Calcium Hydroxide on Root Canal Walls in Natural Open Apex Teeth: An In Vitro Study

INTRODUCTION

Endodontic therapy is challenging in open apex teeth. One of these problems is the residue of medicaments on root canal walls. The aim of this study was to evaluate the amount of residual materials on canal walls after the use as medicaments within natural open apex teeth.

METHODS AND MATERIALS

A total of 45 human extracted single-rooted premolars with open apices were selected. After cutting off the crowns, root canals were gently instrumented using #40 files and irrigated with 0.5% sodium hypochlorite. The samples were randomly divided into three groups: calcium hydroxide (CH), triple antibiotic paste (TAP) and propolis (PP). In these groups, CH, TAP, or PP were placed into the canals, respectively. The samples were then restored with temporary fillings. After one week, instrumentation was again performed as mentioned above. The samples were longitudinally cut and scanned and the remaining material in both halves was evaluated using computer software. One-way ANOVA was used to compare the average paste level remaining on the canal walls.

RESULTS

The residual amount of CH on the canal walls was significantly higher than that of PP (P=0.001). The residual amount of CH was higher than TAP but this difference was not significant (P=0.144); the residual amount of TAP was higher than PP but this difference was not significant, either (P=0.094).

CONCLUSION

PP is superior to CH and TAP in terms of removability from the root canal system within open apex teeth.

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.

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.

Efficacy of self-adjusting file, XP-endo finisher and passive ultrasonic irrigation on the removal of calcium hydroxide paste from an artificial standardized groove

The purpose of this study was to compare the effectiveness of self-adjusting file (SAF), XP-endo finisher (XP), passive ultrasonic irrigation (PUI) and conventional syringe and needle irrigation (SNI) in the removal of Ca(OH)₂ from an artificial groove. Eighty mandibular incisors with single oval canals were prepared to size 40/0.04 and split longitudinally. A standardised groove was prepared in the apical third and filled with Ca(OH)₂ . The root halves were reassembled and divided into two control groups (n = 4) and four experimental groups (n = 18) according to the removal methods used. The amount of residual Ca(OH)₂ was evaluated using a four-grade scoring system. The differences among the groups were analysed using the Kruskal-Wallis test (P < 0.05). SAF, XP and PUI removed significantly more Ca(OH)₂ than SNI (P < 0.001), although there were no significant differences among them (P = 0.209). None of the tested methods could completely clean Ca(OH)₂ from the groove.

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.

Comparison of Conventional Syringe, CanalBrush, EndoActivator, Photon-Induced Photoacoustic Streaming, and Manual Instrumentation in Removing Orange-Brown Precipitate: An In Vitro Study

OBJECTIVE

The aim of this in vitro study was to compare the various techniques for removing precipitate formed after irrigation with sodium hypochlorite (NaOCl) and chlorhexidine (CHX).

BACKGROUND DATA

It is still unclear whether different irrigant activation systems can effectively remove precipitate that is firmly attached to the root canal walls.

METHODS

Eighty-two extracted single-rooted human teeth were instrumented by using the ProTaper rotary system. The roots were irrigated with 5% NaOCl and then 2% CHX to form orange-brown precipitate on the root canal walls. The teeth were sectioned longitudinally, and the amount of precipitate on the canal walls was measured under a stereomicroscope at 15 × magnification before the root halves were reassembled. Then, conventional syringe irrigation (CSI), CanalBrush (CB), EndoActivator (EA) system, photon-induced photoacoustic streaming (PIPS), and manual instrumentation (MI) techniques were used to remove the precipitate, during which 5 mL of distilled water was used for 1 min. The amount of precipitate remaining on the canal walls was measured, and the percentage of precipitate removed was calculated. Data were analyzed by using the Kruskal-Wallis and Mann-Whitney U tests (p = 0.05).

RESULTS

All experimental groups contained residual precipitate. The precipitate was more effectively removed in the MI group than in the other groups (p < 0.05). The CB and EA groups showed better removal than the CSI and PIPS groups (p < 0.05), and there were no significant differences in removal between these latter two groups (p > 0.05).

CONCLUSIONS

None of the techniques used was able to completely remove the orange-brown precipitate from the root canal surfaces.

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 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.

Efficacy of XP-endo finisher files in the removal of calcium hydroxide paste from artificial standardized grooves in the apical third of oval root canals

AIM

To compare the efficacy of the XP-endo finisher file (XP) (FKG Dentaire, La Chaux de Fonds, Switzerland) to that of passive ultrasonic irrigation (PUI) and conventional syringe and needle irrigation (SNI) in the removal of calcium hydroxide paste from an artificial standardized groove in the apical third of root canals.

METHODOLOGY

The root canals of 68 mandibular incisors with single oval canals were prepared using Mtwo instruments (VDW GmbH, Munich, Germany) up to size 40, .04 taper. Each tooth was split longitudinally, and in one half of the root, a standardized groove was prepared in the apical part of the specimen. The grooves were filled with Ca(OH)₂ , and the root halves were reassembled. The roots were randomly divided into two control groups (n = 4) and three experimental groups (n = 20) according to the Ca(OH)₂ methods used: XP, PUI and SNI. The amount of remaining medicament was evaluated under X25 magnification using a 4-grade scoring system. Kappa values were calculated for intra- and interobserver agreement evaluation. The differences in the Ca(OH)₂ scores amongst the different groups were analysed using the Kruskal-Wallis test.

RESULTS

None of the tested methods could completely clean the Ca(OH)₂ from the artificial standardized groove in the apical third of the root canals. XP and PUI removed significantly more Ca(OH)₂ than SNI (P < 0.001), with no significant differences between them (P = 0.238).

CONCLUSIONS

XP and PUI were more effective in removing Ca(OH)₂ from artificial standardized grooves in the apical third of root canals than SNI.

Effect of irrigation technique for removal of triple antibiotic paste on bond strength of MTA to root dentin

This study evaluated the bond strength of mineral trioxide aggregate (MTA) to root canal dentin after the performance of various irrigation procedures to remove triple antibiotic paste (TAP). A total of 56 single-rooted human mandibular premolars were instrumented using a rotary system to size 40 and divided randomly into a control group (no intracanal dressing) and three experimental groups (TAP application for 28 days). TAP was then removed by rinsing with 10 mL 2.5% NaOCl using three irrigation systems (Vibringe sonic irrigation, CanalBrush, and syringe irrigation). The coronal and middle parts of root canals were then obturated with MTA. After storage for 1 week, each specimen was embedded in an acrylic block and sectioned horizontally (2-mm-thick slices) at two levels (coronal and middle). Bond strength of MTA to root canal dentin was assessed in 28 samples per group via push-out test using a universal testing machine. Data from the four groups were compared using one-way analysis of variance. Tukey's test was used for multiple comparisons. Push-out bond strength values were significantly higher in the control and Vibringe groups than in the CanalBrush and syringe irrigation groups (p < 0.001). TAP removal from root canals with the Vibringe irrigation system may increase the push-out bond strength of MTA compared with the use of the CanalBrush or syringe irrigation.

Effect of calcium hydroxide on the bond strength of two bioactive cements and SEM evaluation of failure patterns

The aim of this study was to assess the effect of calcium hydroxide on bond strength of two bioactive cements. One-mm thick longitudinal slabs of root dentin were obtained from freshly extracted human monorradicular teeth (n = 60). Simulated root perforations (1 mm in diameter) were prepared in radicular dentin. Thereafter, the specimens were randomly divided into two groups (n = 30), according to the repair material: MTA (n = 30) and Biodentine (BD) (n = 30). Next, the specimens in each group were further randomly divided into 4 equal subgroups (n = 15) according to the prior use of Ca(OH)2: MTA/Ca(OH)2 and BD/Ca(OH)2 groups: perforations were filled with calcium hydroxide [Ca(OH)2] and after 7 days, it was removed, and MTA and BD groups: calcium hydroxide dressing were not used. Push-out test was performed at a crosshead speed of 1 mm/min. Bond strength values were compared statistically using Kruskal-Wallis test and Dunn's post-test at a significance level of 5%. The failure analysis was performed using a stereoscopic and classified as adhesive, cohesive and mixed. The push-out bond strength of MTA and BD was not affected by the prior use of Ca(OH)2 (p > 0.05). BD yielded higher push-out bond strength values compared with those of MTA, regardless of the use of Ca(OH)2 (p < 0.05). Mixed failures were predominant in all groups. Ca(OH)2 placement for perforations sealing does not alter the bond strength of MTA and BD to the root dentin. BD presented higher bond strength values than MTA. SCANNING 38:240-244, 2016. © 2015 Wiley Periodicals, Inc.

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 different irrigation solutions on triple antibiotic paste removal from simulated immature root canal

To evaluate the effectiveness of different irrigation solutions and ultrasonic activation of irrigation solutions on removal of triple antibiotic paste (TAP) from root canals of the simulated immature teeth. Fifty single-rooted teeth were used. TAP was placed into each root canal, and specimens were stored in distilled water for 4 weeks at 37°C. After 4 weeks, the temporary coronal seal was removed and the samples were randomly divided into five groups as follows: (i) saline; (ii) ultrasonic activation of saline; (iii) NaOCl; (iv) ultrasonic activation of NaOCl; (v) chlorhexidine digluconate (CHX). The amount of remaining TAP on the canal walls was measured under stereomicroscope with 30× magnification. The data were analyzed using a one-way ANOVA and post-hoc Tukey test at a significance level of 0.05. There were statistically differences among CHX and ultrasonic activation of NaOCl and other groups (p < 0.05). There were no significant differences among the ultrasonic activation of saline, NaOCl, and saline groups (p > 0.05). Irrigation solutions and ultrasonic activation of the irrigation solutions could not completely remove the triple antibiotic paste from simulated immature root canals. Ultrasonic activation of the NaOCl gave the best and CHX was the worst results.

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.

Effects of different instrumentation techniques on calcium hydroxide removal from simulated immature teeth

The aim of this study was to evaluate the effectiveness of endodontic instrument systems in the removal of calcium hydroxide [Ca(OH)(2)] from simulated immature teeth. The root canals of 106 human single-rooted teeth were shaped with ProTaper rotary files up to an F5 file size. Simulation of roots with immature apices was carried out using size 4 green 1.5-mm diameter Unicore drills. A non-setting Ca(OH)(2) was injected into each root canal and inserted into the working length using lentulo spiral, after which cotton pellets were placed over canal orifices. The apical and coronal side of the roots were then sealed with 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 five experimental groups according to the method used for Ca(OH)(2) removal (ProTaper, Reciproc, OneShape, WaveOne, and Manual) (n = 20), one positive control group (n = 3) and one negative control group (n = 3). The amount of remaining Ca(OH)(2) in the canal walls was measured under a stereomicroscope at 30× magnification. The data were analyzed using Kruskal-Wallis test and Mann-Whitney U test at a significance level of 0.05. Positive and negative control groups were found to be statistically different from all other groups (p < 0.05). There were no significant differences among the ProTaper, Reciproc, OneShape, WaveOne, and Manual groups (p > 0.05). As a conclusion, none of the techniques completely removed Ca(OH)(2) from simulated immature teeth.

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.

Calcium hydroxide removal in curved root canals with apical transportation In Vitro

Calcium hydroxide (CH) is applied to improve disinfection of root canals in most root canal retreatment. This study aimed to analyze the CH removal efficacy using 7 different root preparing files (K file, pre-curved K file, EndoActivator, Ultrasonic file, pre-curved ultrasonic file, F file and needle irrigation alone) with apical transportation. Standardized models of curved canal with such apical transportation or not were set up before applying CH to root canal for 7 days. Seven techniques described above were used for its removal. Then the roots were disassembled and digital photos were taken. The ratio of residual CH in the overall canal surface was calculated using the image analyzer image pro plus 6.0. The data were analyzed using one-way ANOVA with post hoc Tukey test. Results revealed that CH was effectively removed (P<0.05) by using all 6 mechanical methods except irrigation alone. In curved root canals with apical transportation, EndoActivator, pre-curved ultrasonic file and F file were found to be more effective in removing CH than the other four file (P<0.001), while there was no significant difference among EndoActivator, pre-curved ultrasonic file and F file groups (P>0.05). The percentage of residual CH in the canal with apical transportation was higher than that in the canal without apical transportation (P<0.05). In conclusion, CH can be hardly removed completely. Canal with apical transportation will result in insufficient CH removal. EndoActivator, pre-curved ultrasonic file and F file are more effective in the curved root canal with apical transportation.

Effect of rotary instrument associated with different irrigation techniques on removing calcium hydroxide dressing

Calcium hydroxide [Ca(OH)2 ] residues in root canals may compromise sealing of filling and endodontic treatment success. The aim of this study was to compare the efficacy of using rotary instrument associated with EndoActivator, EndoVac, passive ultrasonic irrigation (PUI), and conventional needle irrigation (CNI), in Ca(OH)2 removal from root canal, by means of scanning electron microscopy (SEM) images. Sixty-six human canines were prepared with the Protaper system up to F5 and filled with Ca(OH)2 . After 7 days, Ca(OH)2 was removed with rotary instrument F5 associated with the irrigation techniques used in each group (n = 15): GI (CNI), GII (EndoVac), GIII (EndoActivator) and GIV (PUI). In all groups 15 mL of 2.5% NaOCl and 3 mL of 17% EDTA were used for Ca(OH)2 removal. The Ca(OH)2 residues was evaluated by SEM in the middle and apical third using a system of scores. The results were analyzed by the Kruskal-Wallis and Dunn tests (α = 0.05). None of the techniques completely removed the Ca(OH)2 from root canals. There was no difference between EndoActivator, EndoVac and PUI (P > 0.05), but the three techniques removed more Ca(OH)2 than the CNI (P < 0,05), in the middle and apical thirds of the root canal. It was concluded that the rotary instrument combined with EndoActivator, EndoVac, and PUI was shown to be more efficient than the rotary instrument combined with the CNI in removing Ca(OH)2 from the root canal.

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.

Efficacy of various irrigation protocols on the removal of triple antibiotic paste

AIM

To compare the efficacy of irrigation protocols on the removal of triple antibiotic paste (metronidazole, ciprofloxacin and minocycline) (TAP) from artificial grooves in root canals.

METHODOLOGY

Root canals in 72 extracted single-rooted teeth were prepared using ProTaper rotary instruments up to size F5. The roots were split longitudinally and a standardized groove was prepared in the apical part of one segment. TAP was placed in the grooves, and the root halves were reassembled. The roots were randomly divided into six experimental groups according to the irrigation protocol used: distilled water, 1% NaOCl, 2.5% NaOCl, 100% ethanol, 17% EDTA and passive ultrasonic irrigation (PUI) with 1% NaOCl. The root segments were disassembled, and the amount of TAP remaining was evaluated under a stereomicroscope at 20× magnification using a four-grade scoring system. The data were evaluated statistically using Kruskal-Wallis and Mann-Whitney U-tests with a 95% confidence level (P = 0.05).

RESULTS

There were significant differences amongst the groups (P < 0.001). Passive ultrasonic irrigation (PUI) with 1% NaOCl removed significantly more TAP than the other irrigating solutions (P < 0.05). Distilled water, 1% NaOCl, ethanol and EDTA were associated with significantly more remaining TAP.

CONCLUSIONS

PUI with 1% NaOCl was more effective in removing TAP from artificial grooves in root canals than other irrigating solutions without ultrasonic agitation. It was not possible completely to remove TAP from root canals.

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.