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Dental pulp and periapical diseases are common conditions in stomatology, caused by various pathogenic microorganisms. Antimicrobial peptides, as new antibiotics, offer promising applications in the irrigation and disinfection medicaments for root canals.One patient with chronic periapical periodontitis was selected to extract the clinical pathogenic bacteria. Porphyromonas gingivalis (Pg) (ATCC 33,277), Streptococcus mutans (Sm) (ATCC 25,175), and Prevotella intermedius (Pi) (ATCC 25,611) were used as test strains. The effects of plantaricin (Pln) 149 on the biofilm formation and growth in infected root canals were evaluated by RT-PCR, laser confocal scanning microscopy, and bacterial diversity analysis. In addition, the cytotoxicity of Pln 149 (100 µg/mL) to human dental pulp stem cells (hDPSCs) was assessed using an MTT assay. Pln 149 exhibited significant inhibitory effects on Pg Sm and Pi (P < 0.05), with significant differences in the biofilm images of the laser confocal scanning microscope (P < 0.05). There were no significant differences in hDPSCs viability or proliferation between the Pln 149 and control groups. Considering the excellent antimicrobial effects and low cytotoxicity, we suggest that Pln 149 might be a promising option for root canal irrigation solutions., (© 2022. The Author(s).)

Objective: To evaluate the effect of the combination of calcium hydroxide (Ca(OH) 2 ) and a novel electrolyzed superoxidized solution at neutral pH, known as OxOral® on Enterococcus faecalis growth in root canals., Methods: Sixty human teeth were used, from which root canals were infected and randomly divided into the following treatment groups: saline solution, saline solution plus Ca(OH) 2 , OxOral®, and OxOral® plus Ca(OH) 2 ., Results: A permanent reduction in bacterial growth was observed at days 1, 6, 12, and 18 after OxOral® plus Ca(OH) 2 treatment from 4.4 ± 0.074 log 10  CFU/mL to 0.0 ± 0.001 log 10  CFU/mL. In addition, alkaline conditions maintenance was observed from application time (pH = 12.2 ± 0.033) to 18 d posttreatment (pH = 12.6 ± 0.083)., Conclusion: The combination of OxOral® and Ca(OH) 2 provides an alkaline pH and inhibits E. faecalis growth into the root canals. Our study opens the possibility for further research on the use of OxOral® in endodontic therapy., Competing Interests: The authors declare that there is no conflict of interest regarding the publication of this article., (Copyright © 2021 Héctor Armando Jimenez-Gonzalez et al.)

Root canal (RC) therapy is the primary treatment of dental-pulp and periapical diseases. The mechanical method and chemical irrigation have limitations in RC therapy. Much attention has focused on exploring more controllable and efficacious antimicrobial methods. Although the introduction of photodynamic therapy (PDT) has provided the ideas for RC debridement, the problems of low photosensitive efficiency and nonsignificant germicidal potency of traditional photosensitizers (e.g., methylene blue) have not been solved. Since the concept of "aggregation-induced emission" (AIE) was proposed, optimization of photosensitizers has been boosted considerably. Herein, an AIE photosensitizer, DPA-SCP, with a strong ability to generate singlet oxygen, is proposed for use as an antibacterial application in infected RCs. The antimicrobial activity of DPA-SCP against Enterococcus faecalis suspensions was tested. To explore the antibacterial ability of this photosensitizer against bacterial-biofilm colonization on the inner walls of RCs, we established a model of bacterial biofilm infection. PDT mediated by DPA-SCP had a significant germicidal effect on E. faecalis suspensions and 21-day biofilms in human RCs. PDT mediated by DPA-SCP could achieve efficiency equivalent to that observed using 1% NaOCl, and lead to no significant change in the dentin surface, chemical corrosion, or cytotoxicity.

Aims: We evaluated and compared EndoActivator, CanalBrush, and passive ultrasonic irrigation (PUI) in the removal of calcium hydroxide and calcium hydroxide with iodoform and p-chlorophenol paste (Calcipast Forte) from artificial standardized grooves in the apical third of root canals., Materials and Methods: A total of 34 mandibular premolars were prepared and then split longitudinally. A standardized groove was prepared in the apical part of both segments. The grooves were filled with either calcium hydroxide or Calcipast Forte, and the segments were reassembled. CanalBrush, EndoActivator, or PUI were used. The amount of remaining medicament was evaluated using a four-grade scoring system., Results: None of the irrigation methods could completely remove the pastes from the grooves. More Calcipast Forte paste was detected compared with calcium hydroxide (P < 0.01). PUI was the least effective method in removing Calcipast Forte., Conclusions: It was more difficult to remove Calcipast Forte than a water-based calcium hydroxide paste., Competing Interests: None

Objective: The aim of this study was to evaluate the efficacy of different irrigation protocols in removing two tricalcium silicate-based sealers from simulated root canal irregularities and root canal walls., Material and Methods: Root canals of 140 single-rooted teeth were instrumented. In one-half of each root, an apical groove was created. The samples were divided into two main groups (n = 70) based on the sealer used. In group 1, the grooves were filled with MTA Fillapex; in group 2, BioRoot RCS. The reassembled root halves were divided into six experimental and one control groups: 2.5% NaOCl-17% EDTA (Passive ultrasonic irrigation [PUI]), 5% NaOCl/9% DualRinse HEDP (PUI), 2.5% NaOCl-7% Maleic acid (PUI), 2.5% NaOCl-17% EDTA (Er:YAG laser activated irrigation [LAI]), 2.5% NaOCl/9% DualRinse HEDP (LAI), 2.5% NaOCl-7% Maleic acid (LAI), Distilled water (Control). Specimens were scored using SEM. The data were analysed using Kruskal-Wallis and Mann Whitney U tests., Results: Maleic acid and DualRinse HEDP removed higher amounts of MTA Fillapex from the grooves compared to EDTA, when used with both activation methods (p < .001)., Conclusions: Ultrasonically activated maleic acid or DualRinse HEDP can be an effective irrigation regimen in removing tricalcium silicate-based sealers., (© 2019 Wiley Periodicals, Inc.)

Background: Endodontic treatment is one of the most widely performed procedures in a dental office. New techniques for enhancing the effectiveness of irrigants are being introduced into the dental market. It is crucial to choose a proper method to obtain the highest possible long-term success of performed endodontic treatment. Sodium hypochlorite (NaOCl) appears to be one of the most common and profitable solutions for root canal irrigation. The activation of a solution may be analyzed in 2 fields, physical - turbulence of flow, and chemical - disintegration of irrigant molecules into very active radicals that improve its activity. While the physical alternations of irrigant flow with different techniques are widely studied, there are not many attempts to approach the subject in chemical terms., Objectives: The aim of the study was to compare the chemical effectiveness of 2 methods of NaOCl activation: ultrasonics vs the Self-Adjusting File system (SAF) as an adjunct to increase the efficacy of the irrigant., Material and Methods: The level of activation was evaluated via a reaction of the activated NaOCl samples, with 9-fluorenol as the starting organic material. The model reaction is based on the oxidation of 9-fluorenol to 9-fluorenon. The evaluation was performed using 1H nuclear magnetic resonance (NMR) spectroscopy, comparing the spectra obtained for the examined mixtures., Results: Nuclear magnetic resonance studies show that the use of ultrasonics resulted in increased chemical degradation of NaOCl as compared to the SAF system and non-agitated samples. The prevalence of chemical activation in the ultrasonic group over the SAF group was almost 3 times higher, 3.11 to 1.20, respectively. The Kruskal-Wallis rank sum test revealed there is a statistically significant difference in distributions between the groups., Conclusions: Both SAF and ultrasonics activate NaOCl. Ultrasonic agitation provided higher chemical activation of NaOCl solution than the SAF. The use of ultrasonic agitation of NaOCl in endodontic treatment will allow us to obtain better long-term clinical results.

The aim of this study was to evaluate the effect of peracetic acid (PAA) as a single irrigant on the smear layer, on the intraradicular dentinal bond strength, and on the penetrability of an epoxy-based resin sealer into the dentinal tubules. A total of 120 roots were distributed into 4 groups according to the irrigant used in root canal preparation: 1% PAA (PAA); 2.5% NaOCl followed by final irrigation with 17% EDTA and 2.5% NaOCl (NaOCl-EDTA-NaOCl); 2.5% NaOCl (NaOCl); and saline solution (SS). The smear layer was evaluated using scanning electron microscopy. The bond strength of an epoxy-based resin sealer (AH Plus) to root dentin was evaluated by the push-out test and penetrability of the sealer into dentinal tubules was observed by confocal laser microscopy. The results were analyzed by the Kruskal-Wallis and the Dunn post-test (α = 0.05). The use of 1% PAA as single root canal irrigant provided smear layer removal and improved the penetrability and bond strength of AH Plus to root dentin in a manner similar to that of the NaOCl-EDTA-NaOCl group (p > 0.05). The NaOCl and SS groups had higher values of smear layer and lower values of sealer penetrability and dentin bond strength than the PAA and NaOCl-EDTA-NaOCl groups (p < 0.05). Thus, 1% PAA has the potential to be used as a single irrigant in root canals.

Objectives To determine the concentration of calcium, iron, manganese and zinc ions after the application of chelator to Enterococcus faecalis biofilms. Material and Methods Fifty bovine maxillary central incisors were prepared and inoculated with E. faecalis for 60 days. The following were used as irrigation solutions: 17% EDTA (pH 3, 7 and 10), 2.5% sodium hypochlorite (NaOCl) combined with 17% EDTA (pH 3, 7 and 10), distilled water (pH 3, 7 and 10), and 2.5% NaOCl. Each solution was kept in the root canal for five minutes. Fifteen uncontaminated root canals were irrigated with 17% EDTA (pH 3, 7 and 10). Six teeth were used as bacterial control. The number of calcium, iron, manganese and zinc ions was determined using flame atomic absorption spectrometry. Mean ± standard deviation (SD) values were used for descriptive statistics. Results Calcium chelation using 17% EDTA at pH 7 was higher than at pH 3 and 10, regardless of whether bacterial biofilm was present. The highest concentration of iron occurred at pH 3 in the presence of bacterial biofilm. The highest concentration of manganese found was 2.5% NaOCl and 17% EDTA at pH 7 in the presence of bacterial biofilm. Zinc levels were not detectable. Conclusions The pH of chelating agents affected the removal of calcium, iron, and manganese ions. The concentration of iron ions in root canals with bacterial biofilm was higher after the use of 17% EDTA at pH 3 than after the use of the other solutions at all pH levels.

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., (© 2016 International Endodontic Journal. Published by John Wiley & Sons Ltd.)

To compare the efficacy of various irrigants (citric acid, ethylenediaminetetraacetic acid (EDTA) and NaOCl) and techniques in removing Ca(OH) 2 in two types of curved root canal systems, simulated root canals with specific curvatures were used to investigate the effects of different irrigants and instruments on Ca(OH) 2 removal. The optimal methods were verified on extracted human teeth. Simulated root canals were assigned to one of two groups based on the irrigation solution: 10% citric acid or 2.5% NaOCl. Each group was divided into four subgroups according to the technique used to remove Ca(OH) 2 . The percentage of Ca(OH) 2 removal in different sections of root canals was calculated. On the basis of the results obtained for the simulated canals, 10% citric acid and 17% EDTA were applied to remove Ca(OH) 2 from the extracted human teeth with curved root canal systems. The teeth were scanned by micro computed tomography to calculate the percentage of Ca(OH) 2 removal in the canals. In simulated root canals, we found that 10% citric acid removed more Ca(OH) 2 than 2.5% NaOCl in the 0-1 mm group from the apex level (P<0.05). Ultrasonic and EndoActivator activation significantly removed more Ca(OH) 2 than a size 30 K file in the apical third (P<0.05). However, there were no significant differences in any sections of the canals for 10% citric acid or 17% EDTA in removing Ca(OH) 2 in extracted human teeth. We concluded that it was effective to remove residual Ca(OH) 2 using the decalcifying solution with EndoActivator or Passive Ultrasonic Irrigation in a curved root canal system. A protocol for Ca(OH) 2 removal was provided based on the conclusions of this study and the methods recommended in previous studies.

Objective: This study evaluated the effect of different filling pastes and cleaning agents on the root dentin of primary teeth using Fourier-transformed Raman spectroscopy (FT-Raman), micro energy-dispersive X-ray fluorescence (µ-EDXRF) and scanning electron microscopic (SEM) analysis., Material and Methods: Eighty roots of primary teeth were endodontically prepared and distributed into 4 groups and filled according to the following filling pastes: Control-no filling (CP), Calen®+zinc oxide (CZ), Calcipex II® (CII), Vitapex® (V). After seven days, filling paste groups were distributed to 4 subgroups according to cleaning agents (n=5): Control-no cleaning (C), Ethanol (E), Tergenform® (T), 35% Phosphoric acid (PA). Then, the roots were sectioned and the dentin root sections were internally evaluated by FT-Raman, µ-EDXRF and SEM. Data was submitted to two-way ANOVA and Tukey tests (α=0.05)., Results: Regarding filling pastes, there was no significant difference in organic content. CP provided the lowest calcium values and, calcium/phosphoric ratio (Ca/P), and the highest phosphoric values. For cleaning agents there was no difference in organic content when compared to the C; however, T showed significantly higher calcium and Ca/P than PA. All groups showed similar results for phosphorus. The dentin smear layer was present after use of the cleaning agents, except PA., Conclusion: The filling pastes changed the inorganic content, however they did not change the organic content. Cleaning agents did not alter the inorganic and organic content. PA cleaned and opened dentin tubules.

Objective: The aim of this study was to investigate the effectiveness of conventional syringe irrigations, passive ultrasonic irrigation (PUI), Vibringe, CanalBrush, XP-endo Finisher, and laser-activated irrigation (LAI) systems in removing double antibiotic paste (DAP) from root canals., Material and Methods: One hundred five extracted single-rooted teeth were instrumented. The roots were split longitudinally. Three standard grooves were created and covered with DAP. The roots were distributed into seven groups: 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 DAP was scored under a stereomicroscope., Results: Group 4, Group 6, and Group 7 removed significantly more DAP than the other protocols in the coronal region. Group 7 was more efficient in the middle region; however, no significant difference was found between Group 7 and Group 6. No differences were found between groups in the apical region either, except for the comparisons between groups 7 and 2, and groups 2 and 3., Conclusions: None of the investigated protocols were able to completely remove the DAP from the grooves. The Vibringe and XP-endo Finisher systems showed results similar to those of conventional needle irrigation.

Objective: The aim of this study was to evaluate the efficiencies of different irrigation protocols and solutions in the removal of calcium hydroxide (Ca[OH]2)., Materials and Methods: Sixty-eight maxillary incisors were used. Root canals were prepared and filled with Ca(OH)2. Two control (n = 4) and six experimental groups (n = 10) were adjusted: Group 1:1% peracetic acid (PAA) + master apical file (MAF); Group 2: 17% ethylenediaminetetraacetic acid (EDTA) + MAF; Group 3: 9% 1-hydroxyethylidene-1,1-bisphosphonate (HEBP) + MAF; Group 4: 1% PAA + ultrasonic activation (UA); Group 5: 17% EDTA + UA; Group 6: 9% HEBP + UA. The cleanliness of root canal thirds were evaluated with scanning electron microscopy. Statistical analysis were performed (α = 0.05)., Results: At coronal thirds; PAA + UA was superior to EDTA + MAF, HEBP + MAF; and PAA + MAF was superior to EDTA + MAF, HEBP + MAF (P < 0.05). At middle thirds; PAA + MAF and PAA + UA were superior to EDTA + MAF and EDTA + UA; and, PAA + UA was superior to HEBP + MAF (P < 0.05). There were no significant differences among the rest of the experimental groups (P > 0.05)., Conclusion: Complete removal of Ca(OH)2could not be achieved by none of the irrigants at all root thirds.

Introduction: The purpose of this study was to evaluate the amount of calcium hydroxide (Ca[OH]2) removed by irrigation with different volumes and activation methods., Methods: One hundred thirty extracted straight, single-rooted human teeth were instrumented to size 45/.04. One hundred twenty teeth were filled with radioactively marked Ca(OH)2 and a gutta-percha point; 10 teeth with only gutta-percha served as a negative control. All specimens were stored in saline solution (7 days at 35°C). After storage, teeth were randomly divided into 12 groups (n = 10). The gutta-percha was taken out, and Ca(OH)2 was removed either by irrigation with different volumes (0 mL, 0.5 mL, 1 mL, 2 mL, 4 mL, or 8 mL) or mechanical activation with a 2- or 4-mL volume using a file (Instr) (FlexMaster size 45/.04; VDW, Munich, Germany), a brush (CanalBrush [CB]; Coltène/Whaledent, Langenau, Germany), or passive ultrasonic irrigation (PUI, smooth wire). Irrigation was performed by alternating 40% citric acid and 3% sodium hypochlorite. Residual Ca(OH)2 was measured by scintillation and expressed as a percentage of the original Ca(OH)2., Results: Increasing the irrigation volume led to a significant decrease (P < .05) of residual Ca(OH)2 (0 mL [98.5%], 0.5 mL [21.7%], 1 mL [16.5%], 2 mL [12.9%], 4 mL [8.7%], 8 mL [5.0%], and negative control [0.0%]). Activation led to less residual Ca(OH)2 (2 mL Instr [12.0%], 2 mL CB [11.7%], 2 mL PUI [9.1%], 4 mL Instr [8.5%], 4 mL CB [7.4%], and 4 mL PUI [6.2%]), with significant differences according to the PUI (P < .05)., Conclusions: No irrigation procedure was able to remove Ca(OH)2 completely. PUI was the most effective activation method. However, irrigation with an 8-mL volume was the most effective., (Copyright © 2016 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.)

Aims: (i) To compare chlorhexidine and QMix(TM) in terms of orange-brown precipitate generation in root canals and (ii) to analyse the precipitate produced by mixing chlorhexidine and QMix(™) with NaOCl to determine whether para-chloroaniline was produced., Methodology: The root canals of 57 single-rooted anterior teeth were prepared using ProTaper Universal rotary instruments up to size F4. Two millilitres of 2.5% NaOCl was used between each instrument change. The specimens were then divided randomly into three groups (n = 19) and irrigated as follows: group 1, 5 mL of distilled water (control group) for 60 s; group 2, 5 mL of 2% chlorhexidine for 60 s; and group 3, 5 mL of QMix for 60 s. The roots were split longitudinally, and one of the halves was photographed using a stereomicroscope. The amount of orange-brown precipitate was evaluated using a four-grade scoring system. The data were analysed statistically using the Kruskal-Wallis and Mann-Whitney U-tests (P = 0.05). To evaluate whether the precipitates included para-chloroaniline, 5 mL of 2% chlorhexidine and 5 mL QMix were separately mixed with 5 mL of 2.5% NaOCl in two flasks. After centrifugation, precipitates were obtained and analysed using (1) H NMR spectra. The data were subjected to statistical analysis using the Kruskal-Wallis and Mann-Whitney tests at a 95% confidence level (P = 0.05)., Results: Chlorhexidine had significantly higher scores than QMix(™) in terms of orange-brown precipitate formed in the root canals (P < 0.001). According to the 1H NMR spectra, para-chloroaniline was present in the mixture of chlorhexidine and NaOCl. However, the mixture of QMix(™) and NaOCl did not result in para-chloroaniline formation., Conclusion: QMix(™) does not form para-chloroaniline when associated with NaOCl., (© 2014 International Endodontic Journal. Published by John Wiley & Sons Ltd.)

Aim: The aim of the present study was to determine the effect of ethylenediaminetetraacetic acid (EDTA) and NaOCl irrigation on the microleakage and interfacial morphology of adhesives bonded to pulp chamber dentin., Methods: The pulp chamber roof of 72 extracted permanent molars was removed. Samples were equally divided into six groups. Pulp chamber dentin was bonded with either Adper Easy One (group 1), Adper Prompt L-Pop (group 2), or Adper Single Bond 2 (Group 3), after irrigation with either normal saline (groups 1a, 2a, 3a) or 17% EDTA and 5.25% NaOCl (groups 1b, 2b, 3b). Composite resin restorations were placed in the pulp chamber. Ten samples per group were subjected to microleakage test and scanning electron microscopic analysis was done in two samples from each group. Data were statistically analyzed using Mann-Whitney and Kruskal Wallis tests at a significance level of P < 0.05., Results: EDTA and NaOCl irrigation of the pulp chamber significantly reduced microleakage in Adper Easy One. However, it had no significant effect on the microleakage of Adper Prompt L-Pop and Adper Single Bond 2., Conclusions: EDTA and NaOCl irrigation of the pulp chamber was not deleterious to the bonding of any of the adhesives tested. While this irrigation regimen had no significant effect on the microleakage of Adper Prompt L-Pop and Adper Single Bond 2, it significantly reduced the microleakage scores in Adper Easy One., (© 2014 Wiley Publishing Asia Pty Ltd.)

Aim: The aim of this study was to evaluate the effect of chlorhexidine and ethanol application on the push-out bond strength and bond durability of fiber posts cemented with an etch-and-rinse adhesive system/resin cement to intraradicular dentin., Materials and Methods: Fifty-four bovine roots were shaped for the cementation of a fiberglass post and received the application of 37% phosphoric acid. They were then randomly divided into three groups, according to the type of dentin treatment (n = 18) performed: no treatment (control group), 100% ethanol, or 2% chlorhexidine. Next, the adhesive system (Adper Scotch Bond Multipurpose Plus, 3M ESPE) was applied to the dentin, according to the manufacturer's instructions. Glass fiber posts were cemented with dual resin cement (Rely X ARC, 3M ESPE). After 48 hours, the specimens were serially sectioned for push-out test analysis, providing two slices from each root third (cervical, medium and apical), one of which was tested immediately and the other stored in distilled water for 180 days. The data were analyzed with three-way analysis of variance (ANOVA) for repeated measures and Tukey's test at a 5% significance level., Results: Intraradicular treatment with chlorhexidine yielded the highest bond strength means, followed by ethanol treatment. The control group presented the lowest bond strength means. Water storage exerted no effect on bond strength values., Conclusion: Both chlorhexidine and ethanol improved push-out bond strength to intraradicular dentin, with the former providing the best results, regardless of the storage time., Clinical Significance: The application of 2% chlorhexidine or 100% ethanol may be an important step that can be taken to enhance bond strength of fiber posts to intraradicular dentin, when dual resin cements are used.

Objective: The aim of this study was to investigate the effects of photon-initiated photoacoustic streaming (PIPS) with various irrigating solutions on the bond strength of a self-adhesive resin cement to root dentin., Materials and Methods: Seventy-two mandibular premolar roots were divided into six groups after post space preparation and treated with a needle irrigation with distilled water and NaOCl, ultrasonic irrigation with NaOCl, PIPS with NaOCl, PIPS with EDTA and PIPS with distilled water at 0.3 W, 15 Hz and 20 mJ per pulse for 60 s. Fiber posts were cemented with a newly marketed, self-adhesive resin cement. The data obtained from the push-out tests were analyzed using analysis of variance (ANOVA) and LSD post-hoc tests (p = 0.05)., Results: PIPS with distilled water resulted in higher push-out values than those of needle (with both distilled water and NaOCl) and ultrasonic irrigation (p < 0.05)., Conclusions: The use of PIPS may provide higher bond strength of self-adhesive resin cement to root dentin than needle and ultrasonic irrigation techniques.

Objective: The aim of this study was to evaluate the effect of calcium hydroxide, double antibiotic paste (DAP) and triple antibiotic paste (TAP) with minocycline, cefaclor and amoxicillin on the micro tensile bond strength (µTBS) of self-etch adhesive to pulp chamber dentin., Materials and Methods: Sixty mandibular first molars were cut horizontally and randomly divided into a control group and five experimental groups, which received an intra-canal dressing, as follows: calcium hydroxide, DAP, TAP with minocycline, TAP with cefaclor and TAP with amoxicillin. After storing the specimens for 4 weeks, the medicaments were removed by irrigation with 10 mL each of the following solution: 2.5% NaOCl, 17% EDTA and distilled water. A self-etch adhesive (Clearfil S3 Bond, Okayama, Japan) was applied and composite resin (Clearfil Majesty Posterior, Kuraray Medical Inc., Japan) was placed into the cavity. A µTBS test was performed on each specimen using a universal test machine., Results: The DAP reduced the µTBS of self-etch adhesive compared to the control group, calcium hydroxide and TAP with minocycline and with cefaclor (p < 0.05). However, the other medicaments did not result in a decreased µTBS of self-etch adhesive to pulp chamber dentin as compared to the control group (p > 0.05)., Conclusions: The use of DAP resulted in a reduced µTBS of self-etch adhesive to pulp chamber dentin.

The aim of this study is to analyze the effect of agitation of ethylenediaminetetraacetic acid (EDTA) with diode laser at different agitation times on root dentin microhardness. Eighty-four specimens were divided randomly into seven groups, as follows: (1) distilled water, (2) 17% EDTA, (3) EDTA with 60 s ultrasonic agitation, (4) EDTA with 10 s laser agitation, (5) EDTA with 20 s laser agitation, (6) EDTA with 30 s laser agitation, and (7) EDTA with 40 s laser agitation. All of the specimens were irrigated with 5% NaOCl and distilled water except the distilled water group. Microhardness values were calculated before and after the procedures. Statistical analyses were performed using one-way ANOVA and Tukey post hoc tests. Statistically significant differences were determined between the distilled water and other groups. Also, statistically significant differences were observed between EDTA with 40 s laser agitation and EDTA, and EDTA with 10 and 20 s laser agitations. Ultrasonic agitation of EDTA affected microhardness of root dentin similar to EDTA (p > .05). All applications decreased the microhardness of root dentin when compared with distilled water. Agitation of EDTA with diode laser for 40 s caused more reduction in microhardness of root dentin when compared with EDTA.

In root canal therapy, irrigating solutions are essential to assist in debridement and disinfection, but their spread and action is often restricted by canal anatomy. Hence, activation of irrigants is suggested to improve their distribution in the canal system, increasing irrigation effectiveness. Activation can be done with lasers, termed laser-activated irrigation (LAI). The purpose of this in vitro study was to compare the efficacy of different irrigant activation methods in removing debris from simulated root canal irregularities. Twenty-five straight human canine roots were embedded in resin, split, and their canals prepared to a standardized shape. A groove was cut in the wall of each canal and filled with dentin debris. Canals were filled with sodium hypochlorite and six irrigant activation procedures were tested: conventional needle irrigation (CI), manual-dynamic irrigation with a tapered gutta percha cone (manual-dynamic irrigation (MDI)), passive ultrasonic irrigation, LAI with 2,940-nm erbium-doped yttrium aluminum garnet (Er:YAG) laser with a plain fiber tip inside the canal (Er-flat), LAI with Er:YAG laser with a conical tip held at the canal entrance (Er-PIPS), and LAI with a 980-nm diode laser moving the fiber inside the canal (diode). The amount of remaining debris in the groove was scored and compared among the groups using non-parametric tests. Conventional irrigation removed significantly less debris than all other groups. The Er:YAG with plain fiber tip was more efficient than MDI, CI, diode, and Er:YAG laser with PIPS tip in removing debris from simulated root canal irregularities.

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.

The purpose of this in vitro study was to evaluate the effect of various chelating solutions on the radicular push-out bond strength of calcium silicate-based and resin-based root canal sealers. Root canals of freshly-extracted single-rooted teeth (n = 80) were instrumented by using rotary instruments. The specimens were randomly divided into 4 groups according to the chelating solutions being tested: (1) 17% ethylenediaminetetraacetic acid (EDTA); (2) 9% etidronic acid; (3) 1% peracetic acid (PAA); and (4) distilled water (control). In each group, the roots were further assigned into 2 subgroups according to the sealer used: (1) an epoxy resin-based sealer (AH Plus) and (2) a calcium silicate-based sealer (iRoot SP). Four 1 mm-thick sections were obtained from the coronal aspect of each root (n = 40 slices/group). Push-out bond strength test was performed at a crosshead speed of 1 mm/min., and the bond strength data were analyzed statistically with two-way analysis of variance (ANOVA) with Bonferroni's post hoc test (p < 0.05). Failure modes were assessed quantitatively under a stereomicroscope. Irrespective of the irrigation regimens, iRoot SP exhibited significantly higher push-out bond strength values than AH Plus (p < 0.05). For both the sealers, the use of chelating solutions increased the bond strength, but to levels that were not significantly greater than their respective controls (p > 0.05). iRoot SP showed higher resistance to dislocation than AH Plus. Final irrigation with 17% EDTA, 9% Etidronic acid, and 1% PAA did not improve the bond strength of AH Plus and iRoot SP to radicular dentin.

Introduction: The purpose of this study was to evaluate the effectiveness of different irrigation systems on removing calcium hydroxide (Ca[OH]2) from the root canal by using a scanning electron microscope., Methods: Forty extracted single-rooted teeth were divided randomly into 4 groups. Canal instrumentation was done, and the teeth were filled with Ca(OH)2 paste. One week later, 4 techniques were used for Ca(OH)2 removal. In the first group, the canals were cleaned with a master apical file. The second, third, and fourth groups were irrigated using the EndoVac (Discus Dental, Culver City, CA), EndoActivator (Dentsply Tulsa Dental Specialties, Tulsa, OK), and ProUltra (Dentsply Tulsa, Tulsa, OK) systems, respectively. All the groups were irrigated with 3 mL (18%) EDTA and 3 mL (1%) NaOCl for 1 minute. The canal walls were viewed, and the remaining amount of Ca(OH)2 was evaluated using a scanning electron microscope. A scoring system was used to assess the amount of residue Ca(OH)2 on each third of the canal. The obtained data for comparisons between the conventional irrigation needle and each device were statistically analyzed using the Mann-Whitney U test., Results: To compare the 4 devices, the results were statistically analyzed using the analysis of variance test., Conclusions: None of the investigated techniques removed the Ca(OH)2 dressing completely. However, the EndoActivator System showed better results in removing Ca(OH)2 in each third of the root canals in comparison with the other techniques., (Copyright © 2015 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.)

Introduction: The aim of this study was to evaluate the effect of calcium hydroxide (CH) and antibiotic pastes, including a mixture of metronidazole and ciprofloxacin, with and without minocycline or cefaclor, on the dislocation resistance of mineral trioxide aggregate (MTA) to root dentin., Methods: Eighty single-rooted human mandibular premolars were selected. The teeth were prepared by using the ProTaper system. The prepared teeth were then instrumented to a #6 Peeso reamer to obtain a standard internal diameter of 1.5 mm. The reamers were passed 1 mm beyond apex to simulate immature teeth. The specimens were then randomly divided into a control group (no intracanal medicament was used) and 4 experimental groups that were treated with an intracanal medicament: CH, double antibiotic paste (DAP) with metronidazole and ciprofloxacin, triple antibiotic paste (TAP) with minocycline, or TAP with cefaclor (n = 16). After 3 weeks, the medicaments were removed, and approximately 3 mm of MTA was placed in the coronal third of the canals. A push-out test was used to measure the dislocation resistance between the root dentin and MTA. Data were analyzed by using one-way analysis of variance and Tukey post hoc tests., Results: The dislocation resistance values of the CH, TAP with minocycline, and TAP with cefaclor groups were similar to those of the control group (P > .05), whereas the DAP group had the lowest dislocation resistance when compared with the other groups (P < .05). Overall, there was a predominance of cohesive failures between root dentin and MTA., Conclusions: The results of this study indicate that the application of DAP as an intracanal medicament reduced the dislocation resistance of MTA to root dentin., (Copyright © 2014 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.)

Introduction: The aim of this study was to evaluate the effects of calcium hydroxide (CH) and triple (TAP) and double (DAP) antibiotic pastes on the bond strength of an epoxy resin-based sealer (AH Plus Jet; Dentsply DeTrey, Konstanz, Germany) to the root canal dentin., Methods: Sixty-four single-rooted human mandibular premolars were decoronated and prepared using the rotary system to size 40. The specimens were randomly divided into a control group (without intracanal dressing) and 3 experimental groups that received an intracanal dressing with either CH, DAP, or TAP (n = 16). The intracanal dressing was removed by rinsing with 10 mL 17% EDTA followed by 10 mL 2.5% sodium hypochlorite. The root canals were then obturated with gutta-percha and AH Plus Jet sealer. A push-out test was used to measure the bond strength between the root canal dentin and the sealer. The data were analyzed using 2-way analysis of variance and Tukey post hoc tests to detect the effect of the independent variables (intracanal medicaments and root canal thirds) and their interactions on the push-out bond strength of the root canal filling material to the root dentin (P = .05)., Results: The push-out bond strength values were significantly affected by the intracanal medicaments (P < .001) but not by the root canal thirds (P > .05). In the middle and apical third, the bond strength of the TAP group was higher than those of the CH and DAP groups (P < .05)., Conclusions: The DAP and CH did not affect the bond strength of the epoxy resin-based sealer. Additionally, the TAP improved the bond strength of the epoxy resin-based sealer in the middle and apical thirds., (Copyright © 2014 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.)

Aim: This study evaluated the push-out bond strength of cemented fiber posts after deproteinization of root canal dentin walls with NaOCl. The effect of the application of an antioxidant solution (sodium ascorbate) was also evaluated., Materials and Methods: A three-step etch-and-rinse (Scotch-bond - 3M Espe) and a one-step self-etching adhesive (Xeno III - Dentsply Caulk) were evaluated. Thirty bovine incisor roots were divided into 3 groups: a. Irrigation with physiologic solution (control). b. Deproteinization with 10 minutes irrigation of 5% NaOCl. c. Deproteinization with NaOCl followed by 10 minutes irrigation with 10% ascorbic acid. Fiber posts were cemented with a dual-cured cement (Rely X ARC - 3M ESPE). The push-out bond strength was evaluated after 24 hours of storage in distilled water. The data were analyzed with three-way ANOVA, one-way ANOVA and Tukey's test (α = 0.05)., Results: There were significant differences between groups (p < 0.05). The bond strength of Scotchbond was not influenced by the deproteinization. Xeno III showed a decrease in bond strength when deproteinized with 5% NaOCl (p < 0.05). For Xeno III, the subsequent irrigation with ascorbic acid was able to reverse the effect of the deproteinization. Considering the radicular thirds, the bond strength varied in the sequence-apical < middle < coronal., Conclusion: Only the all-in-one adhesive was influenced by the deproteinization. Considering the respective control groups, both systems showed similar bond strength results., Clinical Significance: The decreased bond strength of the self-etching adhesive following deproteinization seams to be related to the oxidant effect of the NaOCl solution and the subsequent irrigation with ascorbic acid was able to reverse the effect of the deproteinization.

Aim: The aim was to determine the effect of four different intracanal medicaments on the apical seal of the root canal system in vitro., Methodology: Fifty freshly extracted intact human permanent maxillary central incisors were collected, stored and disinfected. The root canals were prepared to a master apical size of number 50 using step back technique. Depending upon the intracanal medicament used, the teeth were divided randomly into five groups of 10 teeth each including one control group and four experimental groups. Group A: No intracanal medicament. Group B: Calcium hydroxide powder mixed with distilled water. Group C: Calcium hydroxide gutta percha points (calcium hydroxide points). Group D: 1% chlorhexidine gel (hexigel). Group E: Chlorhexidine gutta percha points (Roeko Activ Points). The medication was left in canals for 14 days. Following removal of the intracanal medicament, all the groups were obturated with lateral compaction technique. The apical leakage was then evaluated using dye extraction method with the help of a spectrophotometer., Results: RESULTS were statistically analyzed using Kruskal-Wallis and Mann-Whitney U-test, which showed statistically significant difference among the five groups tested., Conclusion: It can be concluded from this study that the control group showed least amount of leakage, whereas the 1% chlorhexidine gel group showed maximum amount of leakage. Apical leakage was observed with all the experimental groups with little variations in between them. Under the parameters of this study, it can be concluded that use of intracanal medicaments during endodontic treatment has a definite impact on the apical seal of the root canal system.

Introduction: Photon-induced photoacoustic streaming (PIPS) is a novel technique used for the removal of material on root canal walls, such as bacteria and the smear layer. This study evaluated the efficacy of needle irrigation, the EndoActivator System (Dentsply Tulsa Dental Specialties, Tulsa, OK), and PIPS on the removal of antibiotic pastes from an artificial groove created in a root canal., Methods: Root canal preparation was performed up to size #40 on 84 extracted single-rooted teeth using ProTaper rotary instruments (Dentsply Maillefer, Ballaigues, Switzerland). The specimens were then split longitudinally, and 2 standardized grooves were prepared in the coronal and apical part of each segment. Double (DAP) and triple antibiotic pastes (TAP) were placed in the grooves for 4 weeks, and the root halves were reassembled. Needle irrigation, the EndoActivator System, and PIPS were used for the removal of DAP and TAP. The root segments were disassembled, and the amount of remaining antibiotic pastes was evaluated under a stereomicroscope at 20× magnification using a 4-grade scoring system. The data were evaluated statistically using Mann-Whitney U tests with a 95% confidence level (P = .05)., Results: PIPS removed significantly more antibiotic pastes than the EndoActivator and needle irrigation (P < .001). The EndoActivator was superior to needle irrigation in removing antibiotic pastes (P < .001). There were no statistically significant differences between DAP and TAP and between coronal and apical thirds in their removing from artificially created grooves (P > .05)., Conclusions: PIPS was more effective in removing both DAP and TAP from artificial grooves in root canals than the EndoActivator System and needle irrigation. The EndoActivator was also more effective than needle irrigation. It is difficult to completely remove antibiotic pastes from root canals., (Copyright © 2014 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.)

Introduction: Regenerative endodontics aims to re-establish a functional pulp-dentin complex. First, the root canal system is disinfected primarily by irrigants and medicaments. Triple antibiotic paste (TAP), a commonly used intracanal medicament, has been shown to be directly toxic to stem cells at concentrations greater than 0.1 g/mL. Thus, its complete removal is a crucial step in regenerative endodontic procedures. We hypothesized that currently used irrigation techniques do not completely remove TAP from root canal system., Methods: TAP was radiolabeled by the incorporation of I(125), and calcium hydroxide (Ultracal; Ultradent, South Jordan, UT) was radiolabeled with Ca(45). The intracanal medicaments were placed into standardized human root segments and incubated for 28 days at 37°C. Then, canals were irrigated with EndoActivator (Dentsply, Tulsa, OK), passive ultrasonic irrigation, EndoVac (SybronEndo, Coppell, TX), or a syringe/Max-i-Probe needle (Dentsply Rinn, Elgin, IL) using a standardized irrigation protocol in a closed system. Radioactivity levels (counts per minute values) were measured for each tooth before and after the irrigation protocols. Furthermore, the canals were sequentially enlarged and dentin samples collected and evaluated for radioactivity. Data were analyzed with analysis of variance and Bonferroni post hoc testing (P < .05)., Results: Approximately 88% of the TAP was retained in the root canal system regardless of the irrigation technique used (no difference among groups). Furthermore, approximately 50% of the radiolabeled TAP was present circumferentially up to 350 μm within the dentin. Conversely, up to 98% of the radiolabeled intracanal calcium hydroxide was removed, and most residual medicament was found present in the initial 50 μm of dentin., Conclusions: Current irrigation techniques do not effectively remove TAP from root canal systems, possibly because of its penetration and binding into dentin. However, calcium hydroxide is effectively removed with significant less residual presence., (Copyright © 2014 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.)

Introduction: The aim of this study was to evaluate the efficacy of nickel-titanium reciprocating instrument techniques and passive ultrasonic irrigation (PUI) for retreatment in curved canals and obturated with correspondent single cones., Methods: Twenty molars were selected with mesial-buccal canals with curvatures between 20° and 40°, and they were instrumented with a Reciproc R25 instrument (VDW, Munich, Germany) in a reciprocating motion and obturated with single cones and AH Plus sealer (Dentsply Maillefer, Ballaigues, Switzerland). The teeth were divided into 2 groups (n = 10) according to the instrument used for the removal of filling material: group 1: Reciproc R25 instrument and group 2: WaveOne Primary instrument (Dentsply Maillefer). The analysis of the remnant filling material was made through micro-computed tomographic imaging after the use of reciprocating instruments and again after the use of PUI with xylene. The effective time of retreatment was registered., Results: The filling material of the root canal was efficiently removed (P < .05) for both groups. The percentage of removal of filling materials was 93% for the Reciproc group and 92% for the WaveOne group. There were no statistical significant differences (P > .05) between the groups in relation to the removal of filling material ability and the time needed for the procedure. The effective time for the removal of filling material was 78.7 seconds and 89.5 seconds for the Reciproc and WaveOne groups, respectively., Conclusions: It was concluded that both instruments efficiently but not completely removed the filling material from inside the root canals. The use of xylene with PUI increased the removal of filling material a little, but it was not statically significant., (Copyright © 2014 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.)

Introduction: The aim of this study was to evaluate whether or not different final irrigation activation techniques affect the bond strength of an epoxy resin-based endodontic sealer (AH Plus; Dentsply DeTrey, Konstanz, Germany) to the root canal walls of different root thirds., Methods: Eighty single-rooted human mandibular premolars were prepared by using the ProTaper system (Dentsply Maillefer, Ballaigues, Switzerland) to size F4, and a final irrigation regimen using 3% sodium hypochlorite and 17% EDTA was performed. The specimens were randomly divided into 4 groups (n = 20) according to the final irrigation activation technique used as follows: no activation (control), manual dynamic activation (MDA), CanalBrush (Coltene Whaledent, Altststten, Switzerland) activation, and ultrasonic activation. Five specimens from each group were prepared for scanning electron microscopic observation to assess the smear layer removal after the final irrigation procedures. All remaining roots were then obturated with gutta-percha and AH Plus sealer. A push-out test was used to measure the bond strength between the root canal dentin and AH Plus sealer. The data obtained from the push-out test were analyzed using 2-way analysis of variance and Tukey post hoc tests., Results: The bond strength values mostly decreased in the coronoapical direction (P < .001). In the coronal and middle thirds, ultrasonic activiation showed a higher bond strength than other groups (P < .05). In the apical third, MDA displayed the highest bond strength to root dentin (P < .05). The majority of specimens exhibited cohesive failures., Conclusions: The bond strength of AH Plus sealer to root canal dentin may improve with ultrasonic activation in the coronal and middle thirds and MDA in the apical third., (Copyright © 2014 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.)

Introduction: The purpose of this in vitro study was to obtain a better understanding of the mechanism of irrigant traveling apically and generating 2-phase intermittent counter flow in straight root canal models during activation of the irrigant by ultrasonic means in an endodontic procedure., Methods: A high-speed imaging system, with high temporal and spatial resolution (FastCam SA5; Photron, Tokyo, Japan) at a frame rate of 100,000 frames per second using a macro lens (60 mm, f/2.8; Nikon, Tokyo, Japan), was used to visualize, in glass models of root canals, an ultrasonically induced acoustic pressure wave in an EDTA solution environment. A 25-mm stainless steel noncutting file #20 driven by an ultrasonic device (P5 Newtron; Satelec Acteon, Mérignac, France) at power settings of 5 and 7 produced disturbances at the solution-air interface., Results: We found that apically directed travel of the irrigant was caused by disruption of the surface tension at the solution-air interface. This disruption caused by ultrasonic activation energy displaced air in the form of bubbles from the apical region toward the solution., Conclusions: The apical movement of the solution may be attributed to ultrasonically induced wave generation at the solution-air interface, resulting in the removal of trapped air from the root canal and allowing the solution to travel apically in the opposite directions (via a 2-phase intermittent counter flow)., (Copyright © 2014 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.)

This study aimed to compare the effectiveness of different intracanal irrigation techniques in removing intracanal medicaments prior to obturation. A total of 168 single roots were prepared with ProTaper® rotary files and medicament pastes applied (Ledermix®, Odontopaste®, Doxypaste and Pulpdent®), left in for 2 weeks, then removed using filing followed by one of four methods: irrigation with an open-ended notched irrigation needle (Appli-Vac) either at the working length or 5 mm from the canal orifice, or the Max-I-probe or EndoActivator® at the working length. Following the removal of medicaments, the roots were split into two and the internal surfaces photographed, for digital image analysis of the overall percentage of residual medicament. With the exception of canals irrigated 5 mm apical to the root canal orifice, all four irrigation techniques achieved an average of 95% for removal of Ledermix®, Odontopaste® and Doxypaste. Calcium hydroxide paste was the most difficult medicament to remove, with no difference between irrigation techniques. Up to 27% of the Pulpdent® material remained after irrigation. No irrigation technique could completely remove all traces of medicaments. The position of the irrigational needle and the type of medicament used are key factors, which influence the effectiveness of irrigation in removing medicaments., (© 2013 Australian Society of Endodontology.)

Introduction: The aim of this study was to compare the efficacy of conventional syringe, ultrasonic, EndoVac (Discus Dental, Culver City, CA), and Self-Adjusting File (SAF) (Re-Dent-Nova, Ra'nana, Israel) irrigation systems in removing calcium hydroxide (Ca[OH]2) from simulated root canal irregularities., Methods: The root canals of 88 extracted single-rooted teeth were prepared using ProTaper rotary instruments (Dentsply Maillefer, Ballagiues, Switzerland) up to size F4. The roots were split longitudinally, and a standardized groove was prepared in the apical part of 1 segment. The root halves were reassembled, and Ca(OH)2 medicament was placed into the root canals using a Lentulo spiral. The roots were randomly divided into 4 experimental groups and 2 control groups according to the different irrigation systems used: conventional syringe irrigation, continuous passive ultrasonic irrigation (PUI), EndoVac irrigation, and SAF irrigation. Each group was then divided into 2 subgroups (n = 10) according to the irrigation protocol: subgroup 1: 10 mL 2.5% NaOCl and subgroup 2: 10 mL 17% EDTA + 10 mL 2.5% NaOCl. The amount of remaining medicament was evaluated under a stereomicroscope at 30× magnification using a 4-grade scoring system. The influences of the different Ca(OH)2 medicament removal methods and irrigation protocols were statistically evaluated using 2-way analysis of variance and Tukey post hoc tests., Results: In the NaOCl-irrigated groups, PUI removed significantly more Ca(OH)2 medicament than the other techniques (P < .05). There was no significant difference among the other groups (P > .05). In the EDTA/NaOCl-irrigated groups, the SAF and PUI removed significantly more Ca(OH)2 than the other techniques (P < .05)., Conclusions: The use of the SAF system with the combination of EDTA and NaOCl enhanced Ca(OH)2 removal when compared with the use of only NaOCl irrigation with the SAF. Continuous PUI and SAF were more effective than EndoVac, and conventional syringe irrigation in the removal of the Ca(OH)2 medicament from an artificial standardized groove in the apical part of the root canal., (Copyright © 2014 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.)

Aim of this study was to assess the influence of chlorhexidine digluconate (CHX) application on bond strength of glass fibre reinforced composite (FRC) posts to root dentine using adhesive luting systems. Forty extracted human mandibular premolars were endodontically treated and root canals were prepared. Teeth were divided into 2 groups according to luting system as SuperBond C&B (etch-and-rinse/chemical cure) and FuturaBond DC (self-etch/ dual cure). Each group was further divided in 2 subgroups (n=10) according to whether CHX was applied or not. Group Futura/CHX: FuturaBond DC + CHX; group Futura: FuturaBond DC; group Super/CHX: Super Bond C&B + CHX; group Super: SuperBond C&B + CHX. Mean and standard deviation (in parenthesis) values of bond strength in MPa were: group Futura/CHX: 8.86 (1.96), group Futura: 7.65 (1.01), group Super/CHX: 17.47(2.93), group Super: 12.41 (3.83). Bond strength values were affected by the type of luting agent and CHX irrigation (p=0.001, two-way ANOVA). There were statistically significant differences among the groups according to one-way ANOVA (p<0.001). Significant differences were observed in bond strength between groups Super/CHX and Super (p=0.023), between groups Futura/CHX and Super/CHX (p<0.001). Application of CHX before luting procedure with etch-and-rinse/chemical cure luting agent of glass FRC post improved long-term bond strength between glass FRC and root dentine.

Introduction: Root canal irrigation is vital to thorough debridement and disinfection, but the mechanisms that contribute to its effectiveness are complex and uncertain. Traditionally, studies in this area have relied on before-and-after static comparisons to assess effectiveness, but new in situ tools are being developed to provide real-time assessments of irrigation. The aim in this work was to measure a cross section of the velocity field in the fluid flow around a polymer rotary finishing file in a model root canal., Methods: Fluorescent microparticles were seeded into an optically accessible acrylic root canal model. A polymer rotary finishing file was activated in a static position. After laser excitation, fluorescence from the microparticles was imaged onto a frame-transfer camera. Two consecutive images were cross-correlated to provide a measurement of a projected, 2-dimensional velocity field., Results: The method reveals that fluid velocities can be much higher than the velocity of the file because of the shape of the file. Furthermore, these high velocities are in the axial direction of the canal rather than only in the direct of motion of the file., Conclusions: Particle image velocimetry indicates that fluid velocities induced by the rotating file can be much larger than the speed of the file. Particle image velocimetry can provide qualitative insight and quantitative measurements that may be useful for validating computational fluid dynamic models and connecting clinical observations to physical explanations in dental research., (Copyright © 2014 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.)

Purpose: Post and core systems are commonly used to restore endodontically treated teeth. A durable bond between fiber posts and dentin contributes to the success of the restorative treatment. Different irrigants are used during post space preparation and various studies have investigated the effects of these chemical agents on bond strength and dentin morphology., Methods: The MEDLINE-PubMed, Cochrane, and SCOPUS databases were searched for appropriate papers addressing the effects of irrigants on bonding of fiber posts to dentin and on dentin morphology. Databases were searched from 2002 through 2012. The search was performed using a variety of keywords including fiber posts, bond strength, post space preparation, post space irrigation, and smear layer removal., Results: Using multiple key words and different strategies, 68 publications were initially screened. The abstracts of these 68 publications were scanned for relevance, and 50 full-text articles were selected and read in detail. Thirty publications which discussed the effect of various intracanal irrigants on bond strengths of fiber posts and dentin morphology were incorporated in this review. Following review of all relevant papers, it can be concluded that bond strengths of fiber posts to radicular dentin can be affected by the irrigants used and that various irrigants affect different types of resin cements differently.

This study assessed the cross-sectional Knoop microhardness and flexural strength of root dentin exposed to different surface treatments with chemical agents after biomechanical preparation. Root canals from human canines were biomechanically treated and divided into eight groups (n=10) to receive one of the following dentin treatments: I. Deionized water (control); II. 5.25% Sodium hypochlorite (NaOCl); III. NaOCl + 10% Sodium ascorbate (SA); IV. SA; V. 2% Chlorhexidine gel (CHX); VI. 37% Phosphoric acid gel (PA) + CHX; VII. PA; and VIII. PA + NaOCl. The roots were sectioned to obtain specimens that were evaluated for cross-sectional Knoop microhardness and flexural strength using a three-point bending test. ANOVA and Tukey's test were performed. The microhardness in the control group was significantly higher (p < 0.05) than in the groups exposed to chemical agents, which in turn were statistically similar (p > 0.05) to each other. Regarding flexural strength, PA+NaOCl provided statistical higher values than PA+CHX and CHX. However, there was no significant difference between the control group and those groups subjected to surface treatment (p > 0.05). Dentin microhardness was reduced after exposure to NaOCl, CHX, PA, SA and their associations and the flexural strength of radicular dentin was not affected by the chemical agents.

The present study aims to evaluate the antimicrobial effect of two new intracanal preparations against E. faecalis. Thirty single-rooted human canine teeth were used. The crowns were removed and the roots were instrumented using a conventional technique. Three groups of ten teeth each were infected with 108 CFU/ ml of E. faecalis for 21 days. The root canals were flled with new intracanal medications containing 3% doxycycline hydrochloride (DX) or 2% chlorhexidine digluconate (CHX). Ten teeth received no medication (NM)-negative control. Microbial samples were obtained 21 days after contamination: 14 days under the effect of the intracanal medications and 7 days after replacing the medications by BHI broth. The samples were homogenized, diluted, seeded on BHI agar and incubated for 48h/36°C. The number of colony forming units (CFU/ml) was obtained and analyzed statistically. All intracanal dressings significantly reduced the number of bacterial cells in the root canal after 14 days with medication. After the period with 7 days with BHI broth, the CFU counts of E. faecalis remained at low values. However, the NM group showed a significant increase of CFU in this period to similar values of the initial contamination. 3% doxycycline hydrochloride gel and 2% CHX gel were effective to eliminate E. faecalis from the root canal system.

Aim of this study was to evaluate the effect of 7% maleic acid and 17% ethylenediaminetetraacetic acid (EDTA) on the shear bond strength of RealSeal SE sealer to root canal dentin. Twenty incisors were split into coronal, middle and apical third and were treated in the following manner: Group 1: 5 ml of saline (1 minute). Group 2: 2.5% sodium hypochlorite (5 ml/min) followed by 79% maleic acid (5 ml/min). Group 3: 2.5% sodium hypochlorite (5 ml/min) followed by 17% EDTA (5 ml/min). Sealer was the placed on the root dentin and samples were subjected to bond strength measurement. There was no significant difference in bond strength between maleic acid and 17% EDTA in coronal & middle third. However, in apical third, 7% maleic acid showed higher bond strength. Least bond strength was observed with saline. Bond strength was maximum in apical third for both 7% maleic acid and 17% EDTA.

Introduction: The aim of this in vitro study was to assess and compare the effect of photoactivated disinfection (PAD) on the bond strength of root canal sealers to human root canal dentin using the push-out test., Methods: Fifteen extracted human mandibular premolar teeth with single and straight roots were used. After the clinical crowns were removed from the cementoenamel junction, root canals were prepared with the ProTaper (Dentsply Maillefer, Ballaigues, Switzerland) rotary system to the size of the F3 file. The smear layer of the roots was removed using 17% EDTA followed by 5.25% sodium hypochlorite (NaOCl) and distillate water. The roots were then randomly divided into 3 groups (n = 5) according to the final irrigation regimen. In group 1, PAD (FotoSan; CMS Dental, Copenhagen, Denmark) was applied to the root canals and light cured for 20 seconds. Group 2 was finally irrigated with a 2% solution of chlorhexidine gluconate, and group 3 served as the control group (NaOCl + EDTA). All the canals were then obturated with the lateral condensation technique using gutta-percha and AH Plus sealer (Dentsply Maillefer) sealer. One-millimeter-thick horizontal sections from the coronal and midthirds of each root (n: 5 × 4 = 20) were sliced for the push-out bond strength measurement. The data were converted to megapascals and statistically analyzed using 1-way analysis of variance and the post hoc Tukey test., Results: There was no significant difference among the bond strength of PAD, chlorhexidine gluconate, and NaOCl (P > .05)., Conclusions: We conclude that PAD does not adversely affect the bond strength of the AH Plus sealer to root canal dentin and that it can be used for the final disinfection of root canals., (Copyright © 2013 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.)

The aim of this study was to investigate whether a final rinse with Endosolv R® solvent and ultrasound resulted in cleaner root canal walls during endodontic retreatment. A total of 56 extracted premolar teeth were manually instrumented using a step-back flare technique and filled with gutta-percha and AH Plus sealer. After 9 months, the canals were retreated by removing the gutta-percha and sealer with ProTaper Universal Retreatment and rotary preparation with ProTaper Universal System up to an F5 file. As a final step, the teeth were randomly divided in 4 groups (n=14) and were subjected to passive ultrasonic irrigation (PUI) with either Endosolv R or distilled water. In the control groups, the irrigants were left undisturbed. Roots were cleaved and examined under scanning electron microscopy (SEM), and the amount of filling remnants on the canal walls was assessed by two calibrated examiners in a blinded fashion. Data were analyzed by the Kruskal-Wallis test and the Student-Newman-Keuls post hoc test (α=0.05). All groups presented filling debris in the three root canal thirds after retreatment. There were no significant differences between the groups or among the root canal thirds within each group (p>0.05). PUI with Endosolv R was not effective in the removal of filling debris from root canal walls.

Aim: To analyse the effect of calcium hydroxide paste, endodontic irrigants and time of application on the bond strength of fibre posts to root canal dentine., Methodology: Seventy bovine incisors were divided into 7 groups according to removal of calcium hydroxide and distilled water (CHW) (immediate - I; 21 days - 21 days; 6 months - 6 months) and endodontic irrigant (1% sodium hypochlorite - SH; 1% sodium hypochlorite + 17% EDTA - SHE). Fibre posts were cemented (RelyX U100), after which the roots were serially sectioned and submitted to a micro-push-out test. Data were analysed using two-way anova followed by the Tukey's and the Dunnett's tests (α = 0.05)., Results: The CHW groups were not significantly different from the control group in 13 of the 18 associated factors (P > 0.05). There were significant reductions in bond strength in the cervical (P = 0.0216) and middle (P = 0.0017) thirds of the root at 6 months in groups irrigated with SH. Irrigation with SHE reduced the bond strength significantly in the middle (P = 0.0488) and apical (P = 0.0252) thirds of the roots in the immediate groups and in the middle third (P = 0.0287) in the 21-day group. Bond strength was greater in the cervical than in the apical thirds of all immediate and 21-day groups (P < 0.05)., Conclusions: Bond strength of groups that received CH paste was similar to that found in the control group in 13 of the 18 associated factors. EDTA and SH reduced bond strength in specimens in the immediate (middle and apical thirds) and 21-day (middle third) groups. There was a significant reduction in bond strength in the groups irrigated with SH and tested at 6 months (cervical and middle thirds). There was a predominance of adhesive failures between resin cement and dentine in all groups., (© 2012 International Endodontic Journal. Published by John Wiley & Sons Ltd.)

Objective: The goal of this study was to evaluate the efficacy of the Self-Adjusting File (SAF) and ProTaper for removing calcium hydroxide [Ca(OH)2] from root canals., Material and Methods: Thirty-six human mandibular incisors were instrumented with the ProTaper system up to instrument F2 and filled with a Ca(OH)2-based dressing. After 7 days, specimens were distributed in two groups (n=15) according to the method of Ca(OH)2 removal. Group I (SAF) was irrigated with 5 mL of NaOCl and SAF was used for 30 seconds under constant irrigation with 5 mL of NaOCl using the Vatea irrigation device, followed by irrigation with 3 mL of EDTA and 5 mL of NaOCl. Group II (ProTaper) was irrigated with 5 mL of NaOCl, the F2 instrument was used for 30 seconds, followed by irrigation with 5 mL of NaOCl, 3 mL of EDTA, and 5 mL of NaOCl. In 3 teeth Ca(OH)2 was not removed (positive control) and in 3 teeth canals were not filled with Ca(OH)2 (negative control). Teeth were sectioned and prepared for the scanning electron microscopy. The amounts of residual Ca(OH)2 were evaluated in the middle and apical thirds using a 5-score system., Results: None of the techniques completely removed the Ca(OH)2 dressing. No difference was observed between SAF and ProTaper in removing Ca(OH)2 in the middle (P=0.11) and the apical (P=0.23) thirds., Conclusion: The SAF system showed similar efficacy to rotary instrument for removal of Ca(OH)2 from mandibular incisor root canals.

Introduction: The aim of this study was to evaluate the influence of different irrigation protocols on resin-based sealer bond strength to dentin and the associated failure pattern., Methods: One hundred eighty single-rooted premolars were used. Roots were divided into 18 groups according to the irrigation protocol used and instrumented using 5.25% NaOCl or 2% chlorhexidine (CHX) gel as chemical auxiliary substances and 17% EDTA or 37% phosphoric acid for smear layer removal. Finally, CHX solution was used as the final irrigant in some groups. Root canals were filled with either gutta-percha and AH Plus (Dentsply, Petropolis, RJ, Brazil) (GP/AH) or Resilon/Real Seal SE (SybronEndo, Orange, CA). Bond strength was measured by the push-out test. Additionally, failure patterns were classified as adhesive, cohesive, and mixed. Data were statistically analyzed by Kruskal-Wallis and Mann-Whitney U tests., Results: In the GP/AH groups, high bond strength values were obtained when NaOCl was associated with phosphoric acid with (6.9 ± 3.9) and without (7.4 ± 3.8) a final flush with CHX. However, when CHX gel was used, the association with EDTA with (7.5 ± 3.2) and without (6.0 ± 2.3) a final flush with CHX solution showed better results. The GP/AH groups mainly showed a cohesive failure pattern. Evaluation of Resilon/Real Seal SE showed that higher bond strength values were reached when CHX was associated with phosphoric acid with (5.2 ± 3.0) and without (4.2 ± 2.0) a final flush with CHX solution. The failure patterns were mainly adhesive., Conclusions: Irrigation protocols influenced the bond strength of resin sealers to dentin., (Copyright © 2013. Published by Elsevier Inc.)

Introduction: The objective of this study was to evaluate the alterations in the pH of calcium hydroxide (Ca[OH]2), 2% chlorhexidine (CHX) gel, and their combination after adding dentin powder from the root canal walls and the pulp chamber floor., Methods: Ca(OH)2 paste, 2% CHX gel, and their combination were examined. Dentin powder was obtained from the root canal walls and the pulp chamber floor of bovine teeth and added as 1.8% to the volume of the medications. The pH values of the mixtures were assessed immediately after preparation, after 24 hours, and on days 7 and 14. Data were analyzed statistically by analysis of variance and the Student's t test (P = .05)., Results: pH values of Ca(OH)2 were always above 12 in the presence or absence of dentin powder during the 14 days of the study. A significant decrease in pH values of Ca(OH)2 was observed after 14 days when dentin from the root canal wall was added (P < .001). The pH values of CHX gel were significantly increased by the presence of dentin (P = .001). The t test showed a significant difference in the increase of the pH values when the different dentin types were added (P = .002). The pH of the Ca(OH)2 and CHX gel combination was not influenced by dentin powder from the root canal walls, and a reduction was observed after 14 days, exactly like in the control group. The pH values of the combination did not alter after 14 days when pulp chamber floor dentin was added., Conclusions: The different dentin types variably affect the pH of Ca(OH)2 paste, 2% CHX gel, and their combination in the studied periods., (Copyright © 2013. Published by Elsevier Inc.)

Aim: Compare the efficiency in removing two calcium hydroxide [Ca(OH)2] preparations from root canal and apical third using single use syringe, ultrasonics and RinsEndo((®)) with saline solution., Materials and Methods: One hundred and eighty human singlerooted teeth were instrumented using ProTaper((®)) rotary system, divided into two groups according to Ca(OH)2 filling. A: Powder mixed with water, B: Pulpdent((®)). Each group was divided into three subgroups for the irrigation: A1, B1: Single use syringe; A2, B2: Ultrasonics; A3, B3: RinsEndo((®)). Teeth were split longitudinally, photographed and imported into Adobe Photoshop. The percentage ratios of Ca(OH)2 remaining in the canal and in the apical third were calculated. Data were statistically analyzed using 'ANOVA two-way' and 'univariate tests'., Results: (a) Remnants of medicament were found in all teeth, (b) no statistically significant difference in the elimination of both Ca(OH)2 from the entire canal (p = 0.436), however, mixed powder was better eliminated from the apical third (p = 0.005), (c) no statistically significant difference among the irrigation techniques in the whole canal (p = 0.608), though, RinsEndo((®)) and ultrasonics were the most effective in cleaning the apical third (p = 0.032) when mixed powder was used., Conclusion: None of the techniques removed completely Ca(OH)2 from the canal. In the apical third, RinsEndo((®)) and ultrasonics were the most effective when mixed powder was used., Clinical Significance: Ca(OH)2, the most commonly used intracanal dressing, should be completely eliminated before the obturation to assure a good endodontic sealing. Based on the results of this study, RinsEndo((®)) and ultrasonics were the most effective in removal of Ca(OH)2 especially the powder mixed with water presentation.

Introduction: Irrigation dynamics and antibacterial activity determine the efficacy of root canal disinfection. Sonic or ultrasonic agitation of irrigants is expected to improve irrigation dynamics. This study examined the effects of microbubble emulsion (ME) combined with sonic or ultrasonic agitation on irrigation dynamics and reduction of biofilm bacteria within root canal models., Methods: Two experiments were conducted. First, high-speed imaging was used to characterize the bubble dynamics generated in ME by sonic or ultrasonic agitation within canals of polymer tooth models. Second, 5.25% NaOCl irrigation or ME was sonically or ultrasonically agitated in canals of extracted teeth with 7-day-grown Enterococcus faecalis biofilms. Dentinal shavings from canal walls were sampled at 1 mm and 3 mm from the apical terminus, and colony-forming units (CFUs) were enumerated. Mean log CFU/mL values were analyzed with analysis of variance and post hoc tests., Results: High-speed imaging demonstrated strongly oscillating and vaporizing bubbles generated within ME during ultrasonic but not sonic agitation. Compared with CFU counts in controls, NaOCl-sonic and NaOCl-ultrasonic yielded significantly lower counts (P < .05) at both measurement levels. ME-sonic yielded significantly lower counts (P = .002) at 3 mm, whereas ME-ultrasonic yielded highly significantly lower counts (P = .000) at both measurement levels. At 3 mm, ME-ultrasonic yielded significantly lower CFU counts (P = .000) than ME-sonic, NaOCl-sonic, and NaOCl-ultrasonic., Conclusions: Enhanced bubble dynamics and reduced E. faecalis biofilm bacteria beyond the level achieved by sonic or ultrasonic agitation of NaOCl suggested a synergistic effect of ME combined with ultrasonic agitation., (Copyright © 2012 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.)

Purpose: To analyze in vitro, trough scanning electron microscope (SEM), the shaping ability of NRT NiTi rotary system (Mani, Inc, Toshigi-Ken, Japan)., Methods: Ten extracted human teeth were cut at the level of the CEJ and prepared with Gates-Glidden burs 4-3-2 and NRT rotary files up to size #35. Irrigation was performed with 7.5 mL of 5% NaOCl and 7.5 mL of 10% EDTA during each canal instrumentation. Following the shaping sequence, a final irrigation was performed with EDTA followed by NaOCl, each left in situ for three minutes. Teeth were then fractured longitudinally, and the coronal, middle, and apical thirds of the canals were inspected with SEM. Three parameters, divided into four different levels (Alfa and Bravo, considered clinically acceptable; Charlie and Delta, considered clinically unacceptable), were used to score the canal morphology: presence and amount of smear layer; presence of organic and inorganic debris; surface profile., Results: SEM assessment revealed that in the coronal and middle third the majority of canals shaped with NRT rotary system presented a clinically acceptable surface. The apical third presented a higher amount of smear layer and dentinal debris instead, compared to the coronal and middle third., Conclusions: NRT files demonstrated that they provided good instrumentation of the coronal and middle third, while being unable to obtain a defects-free surface in the apical third.