Assessing the efficacy of various irrigation solutions in dissolving organic tissue.

For successful root canal treatment, adequate chemomechanical instrumentation to eliminate microorganisms and pulp tissue is crucial. This study aims to assess the organic tissue dissolving activity of various irrigation solutions on bovine tooth pulp tissue. 40 extracted bovine mandibular anterior teeth (n = 10) were used for the study. Bovine pulp pieces (25 ± 5 mg) were placed in 1.5 ml Eppendorf tubes. Each tooth pulp sample was then covered with 1.5 ml of different irrigation solutions, dividing them into four groups: Group 1 with freshly prepared 5% Boric acid, Group 2 with 5% NaOCl, Group 3 with Irritrol, and Group 4 with Saline. Samples were left at room temperature for 30 min, then dried and reweighed. The efficacy of tissue dissolution ranked from highest to lowest was found to be NaOCl, Boric Acid, Irritrol, and saline (p < 0.05). It was observed that the decrease in the NaOCl group was greater than the decrease in the Irritrol and saline groups, and the decrease in the Boric acid group was significantly greater than the decrease in the saline group (p < 0.05). It also emphasizes the need for future studies to further investigate the effects of Irritrol and Boric Acid on tissue dissolution.

Comparative effects of 17% ethylenediaminetetraacetic acid and 9% etidronic acid applied with different irrigant activation techniques on the release of growth factors from dentin: in vitro study.

BACKGROUND: Growth factors embedded in the extracellular matrix of the dentin play an important role in the migration, proliferation, and differentiation of dental pulp stem cells in regenerative endodontics. In regenerative endodontic treatments, the type of irrigation solution used is crucial for the release of growth factors (GFs) from the dentin matrix. This study evaluated the effectiveness of different irrigant activation techniques (IAT) using two different chelating agents, 17% ethylenediaminetetraacetic acid (EDTA) and 9% etidronic acid (HEDP), in terms of their GF release. METHODS: Seventy-two mandibular premolar teeth were prepared to simulate an open apex. The root fragments were irrigated with 20 ml of 1.5% sodium hypochlorite and 20 ml of saline solution. Eight root fragments were randomly separated for the control group, and the remaining 64 fragments were randomly separated into eight groups based on two different chelating agents (17% EDTA and 9% HEDP) and four different IAT ((conventional needle irrigation (CNI), passive ultrasonic irrigation (PUI), sonic activation with EDDY, and XP-endo Finisher (XPF)). TGF-ß1, VEGF-A, BMP-7 and IGF-1 release levels were determined using an ELISA, and statistical analysis was performed using the Kolmogorov-Smirnov test, ANOVA, and the Tukey test (p < .05). RESULTS: Compared to the control group, the experimental groups showed significantly higher GF release when using EDTA or HEDP. Among the activation groups, the EDDY group triggered the highest GF release, and the CNI group triggered the lowest. CONCLUSIONS: IAT with EDTA and HEDP can increase GF release, with EDDY being the most effective IAT method. Using chelating agents with IAT may be beneficial in regenerative endodontic treatments.

Development of clobetasol-loaded biodegradable nanoparticles as an endodontic intracanal medicament.

AIM: The aim of current study is the development and optimization of biodegradable polymeric nanoparticles (NPs) to be used in the field of Endodontics as intracanal medication in cases of avulsed teeth with extended extra-oral time, utilizing PLGA polymers loaded with the anti-inflammatory drug clobetasol propionate (CP). METHODOLOGY: CP-loaded nanoparticles (CP-NPs) were prepared using the solvent displacement method. CP release profile from CP-NPs was assessed for 48 h against free CP. Using extracted human teeth, the degree of infiltration inside the dentinal tubules was studied for both CP-NPs and CP. The anti-inflammatory capacity of CP-NPs was evaluated in vitro measuring their response and reaction against inflammatory cells, in particular against macrophages. The enzyme-linked immunosorbent assay (ELISA) was used to examine the cytokine release of IL-1ß and TNF-α. RESULTS: Optimized CP-NPs displayed an average size below 200 nm and a monomodal population. Additionally, spherical morphology and non-aggregation of CP-NPs were confirmed by transmission electron microscopy. Interaction studies showed that CP was encapsulated inside the NPs and no covalent bonds were formed. Moreover, CP-NPs exhibited a prolonged and steady release with only 21% of the encapsulated CP released after 48 h. Using confocal laser scanning microscopy, it was observed that CP-NPs were able to display enhanced penetration into the dentinal tubules. Neither the release of TNF-α nor IL-1ß increased in CP-NPs compared to the LPS control, displaying results similar and even less than the TCP after 48 h. Moreover, IL-1ß release in LPS-stimulated cells, decreased when macrophages were treated with CP-NPs. CONCLUSIONS: In the present work, CP-NPs were prepared, optimized and characterized displaying significant increase in the degree of infiltration inside the dentinal tubules against CP and were able to significantly reduce TNF-α release. Therefore, CP-NPs constitute a promising therapy for the treatment of avulsed teeth with extended extra-oral time.

Effect of canal medicaments triple antibiotic paste, Bio-C Temp, and Nano-silver gel activated by visible blue light on canal dentin microhardness and extrusion bond strength of AH plus sealer: A SEM and EDX analysis.

AIM: Assessment of contemporary canal medicaments (Triple antibiotic paste (TAP), Bio-C Temp, and Nano silver gel activated by visible blue light on the dentin microhardness (MH) and push-out bond strength (PBS) of AH plus endodontic sealer. METHOD: Sixty extracted premolars were obtained and decontaminated. Canal cleaning and shaping were performed. The samples were randomly allocated into four groups based on the intracanal medicaments. Group 1= CH paste, Group 2= TAP, Group 3= Bio-C Temp, and Group 4= Nano-silver gel activated by visible blue light. MH assessment was performed using a Vickers Microhardness tester. Forty specimens, ten from each group underwent root canal obturation. PBS and failure mode evaluation were performed. ANOVA and Post Hoc Tukey test were utilized to conduct intra and inter-group comparisons. RESULTS: The maximum outcome of surface hardness was presented by Group-3 (Bio-C Temp®) specimens. However, minimum scores of MH were displayed by Group 1 (CH) treated teeth. The highest outcomes of EBS were exhibited by the cervical third of Group 3 (Bio-C Temp®) samples. The apical section of Group 4 Teeth with Nano Silver gel activated by visible blue light revealed the lowest scores of bond integrity. CONCLUSION: Bio-C Temp and TAP proved to be better intracanal medicament than other tested groups in terms of the push-out bond strength of the sealer. TAP displayed lower microhardness as compared to the Bio-C Temp.

Comparation of the effectiveness of conventional needle irrigation and photon-induced photoacoustic streaming with sodium hypochorite in the treatment of teeth with apical periodontitis: a randomized clinical trial.

Photon-initiated photoacoustic streaming (PIPS) with an Er: YAG laser has been introduced in root canal treatment to improve irrigation and facilitate the removal of bacteria in the root canal system. This study aimed to compare the antibacterial effectiveness of two different root canal irrigation techniques, conventional needle irrigation (CNI) and PIPS, using 1% sodium hypochlorite (NaOCl), in the treatment of teeth with apical periodontitis. Sixty patients with a total of sixty teeth affected by apical periodontitis were included in this study. The teeth underwent root canal therapy, and after mechanical instrumentation, they were randomly assigned to two groups (n = 30) based on the final irrigation protocol: CNI or PIPS with 1% NaOCl. Bacterial suspensions in the root canals were evaluated using Adenosine 5'-triphosphate (ATP) assay kit after mechanical instrumentation and after final irrigation. Then, a follow-up was conducted after 7 days. The results revealed that final irrigation significantly reduced ATP values in both the CNI and PIPS groups (P < 0.001). The ATP values after final irrigation was greater in the CNI group compared to the PIPS group (P < 0.001). After a 7-day follow-up, percussion tenderness and fistula were significantly resolved in both groups (P < 0.05). A multivariate linear regression model was used to identify the factors that influence post irrigation ATP values. The analysis demonstrated that pre-operative percussion tenderness (P = 0.006), the presence of a fistula (P < 0.001) and the method used in the final irrigation (P < 0.001) had a significant impact on the ATP value after final irrigation. These results indicate that employing PIPS with 1% NaOCl as the final irrigation protocol exhibited superior antibacterial effectiveness and has the potential to enhance clinical outcomes in the treatment of teeth afflicted with apical periodontitis.

Efficacy of mixed diclofenac solutions against root canal biofilms.

The objective of this research was to evaluate the efficacy of diclofenac sodium solutions, with or without cetrimide (CTR) added, against polymicrobial root canal biofilms grown in dentin specimens. The study groups were: (1) 5% diclofenac sodium (DCS); (2) 2.5% DCS; (3) 2.5% DCS + 0. 2% CTR; (4) 2.5% DCS + 0.4% CTR and (5) 0.9% saline solution (SS) as the control. After 5 min of solution contact with the biofilms, the antimicrobial activity was evaluated by means of the adenosine triphosphate (ATP) assay as well as confocal laser scanning microscopy (CLSM). Microbial quantification was indicated as the percentage reduction of relative light units (RLUs) for the ATP assay, the Log10 total biovolume and the viability percentage (green cells) for CLSM. Solutions of 2.5% DCS + 0.4% CTR and 5% DCS showed the highest antimicrobial efficacy. Cetrimide increased the antibiofilm activity of diclofenac sodium against endodontic biofilms.

Antimicrobial and cleaning effects of ultrasonic-mediated plasma-loaded microbubbles on Enterococcus faecalis biofilm: an in vitro study.

BACKGROUND: Enterococcus faecalis (E. faecalis) is the most frequently isolated bacteria from teeth with root canal treatment failure. This study aims to evaluate the disinfection effect of ultrasonic-mediated cold plasma-loaded microbubbles (PMBs) on 7d E. faecalis biofilm, the mechanical safety and the mechanisms. METHODS: The PMBs were fabricated by a modified emulsification process and the key reactive species, nitric oxide (NO) and hydrogen peroxide (H2O2) were evaluated. The 7d E. faecalis biofilm on human tooth disk was constructed and divided into the following groups: PBS, 2.5%NaOCl, 2%CHX, and different concentrations of PMBs (108 mL-1, 107 mL-1). The disinfection effects and elimination effects were verified with confocal laser scanning microscopy (CLSM) and scanning electron microscopy (SEM). Microhardness and roughness change of dentin after PMBs treatment were verified respectively. RESULTS: The concentration of NO and H2O2 in PMBs increased by 39.99% and 50.97% after ultrasound treatment (p < 0.05) respectively. The CLSM and SEM results indicate that PMBs with ultrasound treatment could remove the bacteria and biofilm components effectively, especially those living in dentin tubules. The 2.5% NaOCl presented an excellent effect against biofilm on dishes, but the elimination effect on dentin tubules is limited. The 2% CHX group exhibits significant disinfection effect. The biosafety tests indicated that there is no significant changes on microhardness and roughness after PMBs with ultrasound treatment (p > 0.05). CONCLUSION: PMBs combined with ultrasound treatment exhibited significant disinfection effect and biofilm removal effect, the mechanical safety is acceptable.

Antimicrobial effectiveness of different irrigation activation techniques on teeth with artificial internal root resorption and contaminated with Enterococcus faecalis: a confocal laser scanning,icroscopy analysis.

This study aimed to compare the antibacterial efficacy of standard needle irrigation (SNI), EDDY, passive ultrasonic irrigation (PUI), photon-induced photoacoustic streaming (PIPS), and shock wave enhanced emission photoacoustic streaming (SWEEPS) activation on the teeth with simulated internal root resorption (IRR) and contaminated with Enterococcus faecalis (E. faecalis) using confocal laser scanning microscopy (CLSM) analyses. A total of 79 human maxillary central incisors with a single canal were selected. The canals were accessed, and then, the roots were split in the bucco-lingual direction. Artificial IRR cavities (depth of 0.8 mm and a diameter of 1.6 mm) were prepared using round burs and 20% nitric acid in the middle region of the root halves. The root halves were reconstructed with cyanoacrylate glue, and the canals were contaminated with a culture of E. faecalis for 30 days. Root canal preparation was performed using the ProTaper Next rotary files up to X5 and 2.5% NaOCl irrigation. Teeth were randomly assigned to five groups according to the irrigation activation method (n = 15): SNI, EDDY, PUI, PIPS, and SWEEPS. The final irrigation procedures were performed using a total of 6 mL of 2.5% NaOCl for each tooth with an activation time of 3 × 30 s. The canals were stained with LIVE/DEAD BacLight dye and analyzed with CLSM to determine the percentages of dead bacteria in the biofilm. Two-way ANOVA and post hoc Tukey tests were used for statistical analysis (P < .05). None of the irrigation activation methods tested provided 100% bacterial elimination. There was no significant difference between the irrigation activation methods tested in terms of the percentage of dead bacteria (P > 0.05). In irrigation activation methods other than PIPS, there was no significant difference in the percentage of dead bacteria between the coronal, middle, and apical regions of the roots (P > 0.05). A higher percentage of dead bacteria was found in the middle region compared to the apical region in the PIPS (P < 0.05). Within the limitations of this study, SII, EDDY, PUI, PIPS, and SWEEPS have a similar antimicrobial effect on the teeth with IRR and contaminated with E. faecalis.

Effect of chitosan irrigant solutions on the release of bioactive proteins from root dentin.

OBJECTIVE: To identify the effect of two chitosan solutions on the release of root dentin matrix proteins and to describe the chemical changes observed following conditioning with chelating agents. MATERIALS AND METHODS: The release of dentin sialoprotein (DSP), transforming growth factor-beta 1 (TGF-ß1), vascular endothelial growth factor (VEGF), and platelet-derived growth factor-BB (PDGF-BB) with different chelating agents, including ethylenediaminetetraacetic acid (EDTA), chitosan solution (CS), and nanoparticulate chitosan (CSnp), was investigated. DSP was quantified using an enzyme-linked immunosorbent assay (ELISA). TGF-ß1, VEGF, and PDGF-BB were quantified using a cytokine bead panel (CBA). Raman spectroscopy was performed to identify surface chemical changes. Statistical analysis was performed using Kruskal-Wallis test with Mann-Whitney-Wilcoxon rank-sum test (p < 0.05). RESULTS: TGF-ß1, VEGF, and DSP solubilized in all irrigants tested. CSnp showed the highest concentration of DSP. PDGF-BB did not exceed the detection limits. Raman spectroscopy revealed a decrease in the phosphate and carbonate peaks, representing the chelating effect of EDTA, CS, and CSnp. Additionally, CSnp showed the greatest preservation of the amide I and III content. CONCLUSION: Proteins can be released from dentin via EDTA, CS, and CSnp conditioning. Raman spectroscopic revealed changes in the inorganic content of the root dentin after chelation. Furthermore, use of CSnp facilitated a preservation of the organic content. CLINICAL RELEVANCE: Chelation allows the release of proteins, justifying the use of chelating agents in regenerative endodontics. The chitosan-dentin matrix interaction also promotes the protection of the organic content as an additional benefit to its protein releasing effect.

Synchronized Microbubble Photodynamic Activation to Disinfect Minimally Prepared Root Canals.

INTRODUCTION: The purpose of this study was to evaluate the antimicrobial efficacy of a novel irrigation strategy using synchronized microbubble photodynamic activation (SYMPA) in a minimally prepared single canal. METHODS: Single-canal mandibular incisors were inoculated with Enterococcus faecalis for 3 weeks and randomly allocated to 4 groups based on the irrigation protocols: (1) control (saline), (2) conventional needle irrigation (CI), (3) ultrasonic-assisted irrigation (UI), and (4) irrigation with SYMPA. The first 3 groups were instrumented to size 25.07v (WaveOne Gold Primary; Dentsply Sirona, Johnson City, TN), and the SYMPA group was minimally prepared to size 20.07v (WaveOne Gold Small, Dentsply Sirona). The apical 5 mm was resected for microbiological assessment using the culture technique (colony-forming unit), adenosine-5'-triphosphate-based viability assay (relative luminescence units), and the percentage of live bacteria using confocal laser scanning microscopy. RESULTS: Log colony-forming units from the UI (2.37 ± 0.66) and SYMPA (2.21 ± 0.86) groups showed a reduction compared with the control (5.16 ± 0.75) and CI (4.08 ± 1.19) groups. Relative luminescence unit reduction was significant for UI (619.08 ± 352.78) and SYMPA (415.25 ± 329.51) compared with the control (1213.2 ± 880.03) (P < .05). The percentage of live bacteria was significantly lower in the UI and SYMPA groups compared with the control and CI groups. Although higher microbial reduction was observed in SYMPA compared with UI, there was no statistical significance (P > .05). CONCLUSION: SYMPA in minimally prepared canals showed significant antimicrobial efficacy. The novel irrigation strategy using SYMPA could be an effective disinfection strategy for minimally prepared root canals.

Impact of N-acetylcysteine (NAC) and calcium hydroxide intracanal medications in primary endodontic infection: a randomized clinical trial.

OBJECTIVES: This RCT investigated the impact of N-acetylcysteine (NAC) and calcium hydroxide [Ca(OH)2] intracanal medications (ICMs) in primary endodontic infection with apical periodontitis (PEIAP). MATERIALS AND METHODS: Thirty-six teeth with PEIAP were randomly divided into groups according to the ICM: NAC, Ca(OH)2 + saline solution (SSL), and Ca(OH)2 + 2% chlorhexidine-gel (2% CHX-gel) (all, n = 12). Root canal samples (RCSs) were collected before (s1) and after instrumentation (s2) and after 14 days of ICM (s3). Chemomechanical preparation (CMP) was performed with a Reciproc file and 2.5% NaOCl. Checkerboard DNA-DNA hybridization was used to assess 40 target bacteria species. RESULTS: At s1, bacterial DNA was detected in 100% of RCSs (36/36). All 40 bacterial species were found in PEIAP. The mean number of species per RCS was 17.92 ± 13.18. The most frequent bacteria were S. mitis (65%), E. nodatum (63%), E. faecalis (63%), F. nucl sp vicentii (58%), T. forsythia (58%), and F. periodonticum (56%). CMP reduced the mean number of species per RCS to 6.8 ± 2.36 (p < 0.05). At s3, the intragroup analysis revealed a broader antimicrobial activity for Ca (OH)2 + 2% CHX-gel and NAC than Ca(OH)2 + SSL (p < 0.05). NAC eliminated 8/12 bacteria species resistant to both Ca (OH)2 ICMs, including P. micra, P. nigrescens, T. denticola, A. israelii, P. endodontalis, P. acnes, C. ochracea, and E. corrodens. CONCLUSIONS: Ca (OH)2 + 2% chlorhexidine gel (2% CHX gel) showed a greater bacterial elimination over the number of bacterial species; however, NAC eliminated 8/12 bacteria species resistant to both Ca (OH)2 ICMs (RBR-3xbnnn). CLINICAL RELEVANCE: The use of intracanal medication with a broad antimicrobial activity can optimize root canal disinfection. Ca(OH)2 + 2% CHX gel and NAC showed a broader antimicrobial activity than Ca(OH)2 + SSL against endodontic pathogens in primary root canal infection. TRIAL REGISTRATION: Brazilian Registry of Clinical Trials (REBEC), No. RBR-3xbnnn.

Effect of different activation methods on the intratubular penetration of CaOH2 paste: Ex-vivo analysis by confocal laser scanning microscopy.

The aim of this study was to evaluate the maximum penetration depth (MPD) and penetration area (PA) of CaOH2 paste agitated by different methods and to measure the pH after performing these methods. Fifty-five mandibular premolars were divided into control, GL and 4 experimental groups, GEC, GXP, GEDDY and GI (n = 11), where the paste was agitated with Easy Clean, XP-endo Finisher, EDDY and Irrisonic, respectively. The canals were instrumented and irrigated with NaOCl. The paste was manipulated with propylene glycol and rhodamine B dye. Root sections were examined using confocal laser scanning microscopy. There was no difference between groups regarding PA (p > 0.05). At 5 mm, MPD was greater in GEC than in GL or GEDDY, and greater in GI than in GL (p < 0.05). At 2 mm, MPD was greater in GEC than in the other groups (p < 0.05). In conclusion, both Easy Clean and Irrisonic promoted deeper paste penetration and were associated with higher pH levels.

Comparação da propriedade antimicrobiana da clorexidina e do hipoclorito de sódio como irrigantes endodônticos: revisão integrativa / Comparison between the antimicrobial properties of chlorhexidine and sodium hypochlorite as endodontic irrigants: an integrative review / Comparación de la propiedad antimicrobiana de la clorhexidina y el hipoclorito de sodio como irrigantes endodónticos: revisión integradora

Introdução:Durante o tratamento endodôntico, devido às complexidades anatômicas dos canais radiculares, a ação mecânica dos instrumentos não é suficiente para a completa desinfecção dos condutos. Dessa forma, se faz necessário o uso de soluções irrigadoras que possampotencializar a desinfecção do sistema de canais radiculares. Objetivo:Realizar uma revisão integrativa da literatura para comparar as propriedades antimicrobianas da clorexidina com o hipoclorito de sódio.Metodologia:A busca na literatura foi realizada no período de setembro de 2019 a agosto de 2021, nas seguintes bases de dados: PUBMED/MEDLINE, LILACS e SCIELO. Utilizando os descritores: clorexidina, hipoclorito de sódio, irrigante do canal radicular e limpeza. Utilizou-se como critérios de busca, trabalhos experimentais laboratoriais in vitro, publicados entre os anos de 2017 e 2021.Resultados:Foram encontrados 165 artigos, dos quais 15 foram selecionados ao final do processo. 8 trabalhos não encontraram diferença estatisticamente significativa entre a clorexidina e o hipoclorito,5 artigos apresentaram resultados superiores dohipoclorito de sódioem 2 a clorexidina foi superior. Conclusões:Após análise da literatura, observamos semelhança entre a ação antimicrobiana do hipoclorito de sódioe da clorexidina, e podemos concluir que ambas apresentam boa ação antimicrobiana, justificando seu uso clinicamente (AU).

Introduction:During endodontic treatment, due to the anatomical complexities of the root canals, the mechanical action of the instruments is not sufficient for the complete disinfection of the canals. Thus, it is necessary to use irrigating solutions that can makethe disinfection of the root canal system.Objective:Conduct an integrative literature review to compare the antimicrobial properties of chlorhexidine with sodium hypochlorite.Methodology:The literature search was carried out from September 2019 to August 2021, in the following databases: PUBMED/MEDLINE, LILACS and SCIELO. Using the descriptors: chlorhexidine, sodium hypochlorite, root canal irrigant and cleaning. As search criteria, in vitro laboratory experimental works published between 2017 and 2021 were used.Results:A total of 165 articles were found, of which 15 were selected at the end of the process. 8 studies did not find a statistically significant difference between chlorhexidine and hypochlorite, 5 articles showed superior results for NaOCl and in 2 chlorhexidine was superior.Conclusions:After analyzing the literature, we observed a similarity between the antimicrobial action of sodium hypochlorite and chlorhexidine, and we can conclude that both have good antimicrobial action, justifying their clinical use (AU).

Introducción:Durante el tratamiento endodóntico, debido a las complexidades anatómicas de los conductos radiculares, la acción mecánica de los instrumentos no es suficiente para la desinfección completa de los conductos. Por lo tanto, es necesario utilizar soluciones de irrigación que puedan mejorar la desinfección del sistema de conductos radiculares.Objetivo: Realice una revisión integradora de la literatura para comparar las propiedades antimicrobianas de la clorhexidina con el hipoclorito de sodio.Metodología: La búsqueda bibliográfica se realizó desde septiembre de 2019 hasta agosto de 2021, en las siguientes bases de datos: PUBMED/MEDLINE, LILACS y SCIELO. Usando los descriptores: chlorhexidine, sodium hypochlorite, root canal irrigant and cleaning. Como criterio de búsqueda se utilizaron trabajos experimentales de laboratorio in vitro publicados entre 2017 y 2021.Resultados: Se encontraron un total de 165 artículos, de los cuales 15 fueron seleccionados al final del proceso. 8 estudios no encontraron diferencia estadísticamente significativa entre clorhexidinae hipoclorito, 5 artículos mostraron resultados superiores para NaOCl y en 2 la clorhexidina fue superior.Conclusiones: Después de analizar la literatura, observamos una similitud entre la acción antimicrobiana del hipoclorito de sodio y la clorhexidina,y podemos concluir que ambos tienen una buena acción antimicrobiana, lo que justifica su uso clínico (AU).

Cytokine expression and anti-microbial effectiveness of different calcium hydroxide dilutions: An In Vitro study.

Aims: To determine the cytokine expression by human gingival fibroblasts in response to different calcium hydroxide (Ca(OH)2) dilutions and test the effectiveness of these dilutions in root canal dentin infected with Enterococcus faecalis (E. faecalis). Methods: UltraCal XS Ca(OH)2 dilutions were prepared (60, 10, and 1 mg\mL) and co-cultured with gingival fibroblasts for 24 and 48 hours. Untreated cells were used as controls. Expressions of interleukin (IL-1ß), tumour necrosis factor alpha (TNF-α), transforming growth factor beta (TGF-ß), and IL-10 were analysed with real-time polymerase chain reaction (PCR). Root canals of extracted human teeth were inoculated with E. faecalis. After 21 days, canals were medicated with Ca(OH)2 dilutions for 7 days. Samples were taken to determine bacterial reduction using quantitative PCR. Analysis of variance, Tukey post-test, and Wilcoxon matched pair test were used for statistics. Results: IL-1ß and TNF-α expressions of all Ca(OH)2 dilutions were higher at 24 and 48 hours compared to the control. Similarly, all Ca(OH)2 dilutions induced TGF-ß expression at 24 hours compared to the control and continued to be higher in 60 mg/mL groups at 48 hours. In contrast, IL-10 was constitutively expressed by untreated cells in the control group and was down-regulated significantly by all Ca(OH)2 dilutions at 24 and 48 hours. All dilutions demonstrated a significant E. faecalis reduction (P < 0.001) with no significant difference between dilution groups (P > 0.05). Conclusions: All Ca(OH)2 dilutions had a differential inflammatory effect on fibroblasts and had a down-regulation effect to IL-10. All dilutions tested were effective against E. faecalis, with 60 mg/mL having the highest bacterial reduction.

The Impact of Laser-Activated and Conventional Irrigation Techniques on Sealer Penetration into Dentinal Tubules.

Objective: The present study was aimed at comparing the efficacy of 1-hydroxyethylidene-1, 1-diphosphonic acid (HEDP) and ethylenediaminetetraacetic acid (EDTA) by using various final irrigation techniques on penetration of sealer. Background: Traditional irrigation of root canals with a syringe limits the ability of sealer penetration. Various irrigants and activation techniques, including sonic and ultrasonic devices and various kinds of lasers, have been introduced to improve penetration of sealers into dentinal tubules. Methods: One hundred mandibular premolars were selected. Final irrigation was performed with HEDP or EDTA by conventional syringe irrigation (CI), EndoActivator (EA), passive ultrasonic irrigation (PUI), photon-induced photoacoustic streaming (PIPS), and shock wave-enhanced emission photoacoustic streaming (SWEEPS) methods (n = 10). After obturation of root canals with the EndoSequence BC Sealer, samples were evaluated using a confocal laser scanning microscope (CLSM), which enabled measurement of the maximum depth, percentage, and penetration area. Tests performed for analysis included the Kruskal-Wallis H and Mann-Whitney U tests. Results: In the EA method, the penetration percentage achieved using HEDP was significantly higher than EDTA at both sections (p < 0.05). Irrespective of the final irrigation solution employed, the PUI, PIPS, and SWEEPS techniques exhibited greater tubule penetration values compared with the CI and EA techniques (p < 0.05). Conclusions: HEDP and EDTA showed similar effects on the amount of penetrated sealer into the dentinal tubules, and the PUI, PIPS and SWEEPS methods provided enhanced EndoSequence BC Sealer penetration compared with the CI and EA methods. This study was approved by the Near East University institutional review board (#2020/86-1225).

Bactericidal Efficacy of Photon-Induced Photoacoustic Streaming-Erbium:Yttrium-Aluminum-Garnet Laser Combined with Irrigation Solution on Enterococcus faecalis in Curved Root Canals: An In Vitro Study.

Objective: This experiment aimed to study the bactericidal effect of photon-induced photoacoustic streaming (PIPS)-erbium:yttrium-aluminum-garnet (Er:YAG) laser on Enterococcus faecalis in curved root canals. Materials and methods: Sixty-two molars with moderately curved roots (10°-20°) and 62 molars with severely curved roots (25°-40°; one root was selected in each tooth) were assigned to group A and group B, respectively. A curved root canal model with E. faecalis infection was established. Four samples were used for sterility test, and 20 samples were used for testing if the modeling was valid. The remaining 100 samples were randomly divided into 5 subgroups (A1/A2/A3/A4/A5 and B1/B2/B3/B4/B5, n = 10) and treated as follows: A1/B1: PIPS-Er:YAG laser +5.25% sodium hypochlorite (NaOCl); A2/B2: passive ultrasonic irrigation +5.25% NaOCl; A3/B3: PIPS-Er:YAG laser+normal saline (NS); A4/B4: two-hole root canal irrigator +5.25% NaOCl; A5/B5: two-hole root canal irrigator+NS. After treatment, bacterial culture counts and scanning electron microscopic (SEM) observations were carried out for each subgroup, and the bacterial clearance rate of each subgroup was calculated. SPSS 23 software package was used for statistical analysis of the data, and a single-factor analysis of variance was used to compare the subgroups. Results: The bacterial clearance rate in group A was higher than that in group B; however, in each group, A or B, there were significant differences between the subgroups (p < 0.001) except for subgroups 1 and 2 (p > 0.05). SEM revealed that the antibacterial and smear layer removal effect of root canal in subgroups 1 and 2 was better than that in subgroups 3, 4, and 5. Conclusions: PIPS-Er:YAG can significantly enhance the bactericidal effect of NaOCl on E. faecalis in moderately and severely curved root canals.

Effect of irrigation protocols on chemical smear layer formation over the post-space dentin.

This study evaluated the effect of irrigation protocols using 95% ethanol (ET) or 1% peracetic acid (PA) prior the use of 2% chlorhexidine (CHX) compared to distilled water (DW) on the chemical smear layer (CSL) formation and incidence of open dentin tubules at the apical, medium, and cervical third of the post-space dentin. Scanning electron microscopy (SEM) and electron dispersive spectroscopy (EDS) images were used. Forty bovine roots were endodontically treated. After, post-space preparation was performed and the roots were randomized in four groups (n = 10) according to the irrigation protocol: DW, CHX, CHX-ET and CHX-PA. The chemical composition of CSL and the incidence of open dentin tubules at the post-space thirds were evaluated by EDS (500× magnification) and SEM (2000× magnification) images, respectively. Data from chemical composition of CSL were descriptively analyzed, while the incidence of open dentin tubules was evaluated by scores and submitted to Kruskal-Wallis and Dunn test (p = .05). Cl, Bi, and Si were the chemical elements most found over the dentin after the irrigation with CHX and CHX-ET. Moreover, CHX and CHX-ET showed the highest incidence of CSL (p < .05), but without difference between them (p > .05), regardless of the post-space third. DW and CHX-PA showed similar incidence of CSL (p > .05). No difference on the incidence of open dentin tubules was found for any irrigation protocol and post-space third (p > .05). The use of 1% PA prior the post-space irrigation with CHX decrease the incidence of CSL. RESEARCH HIGHLIGHTS: The post-space irrigation with chlorhexidine results in the formation of chemical smear layer. Ethanol is not capable to remove the chemical smear layer. Peracetic acid is more effective to remove the chemical smear layer.

Biochemical changes and macrophage polarization of a silane-based endodontic irrigant in an animal model.

Silane-based/fully hydrolyzed, endodontic irrigant exhibiting antimicrobial properties, is prepared, and is hypothesized to control macrophage polarization for tissue repair. Albino wistar rats were injected with 0.1 ml root canal irrigant, and bone marrow cells procured. Cellular mitochondria were stained with MitoTracker green along with Transmission Electron Microscopy (TEM) performed for macrophage extracellular vesicle. Bone marrow stromal cells (BMSCs) were induced for M1 and M2 polarization and Raman spectroscopy with scratch assay performed. Cell counting was used to measure cytotoxicity, and fluorescence microscopy performed for CD163. Scanning Electron Microscopy (SEM) was used to investigate interaction of irrigants with Enterococcus faecalis. K21 specimens exhibited reduction in epithelium thickness and more mitochondrial mass. EVs showed differences between all groups with decrease and increase in IL-6 and IL-10 respectively. 0.5%k21 enhanced wound healing with more fibroblastic growth inside scratch analysis along with increased inflammation-related genes (ICAM-1, CXCL10, CXCL11, VCAM-1, CCL2, and CXCL8; tissue remodelling-related genes, collagen 1, EGFR and TIMP-2 in q-PCR analysis. Sharp bands at 1643 cm-1 existed in all with variable intensities. 0.5%k21 had a survival rate of BMSCs comparable to control group. Bacteria treated with 0.5%k21/1%k21, displayed damage. Antimicrobial and reparative efficacy of k21 disinfectant is a proof of concept for enhanced killing of bacteria across root dentin acquiring functional type M2 polarization for ethnopharmacological effects.

Effect of Maleic Acid Root Conditioning on Release of Transforming Growth Factor Beta 1 from Infected Root Canal Dentin.

INTRODUCTION: Chemically released growth factors play a vital role in regenerative endodontics. Transforming growth factor beta 1 (TGF-ß1) is 1 of the most extensively studied bioactive molecules that promotes cell proliferation, differentiation, and chemotaxis. The goal of the current research was to analyze the effect of 7% maleic acid (MA) root conditioning of an infected root canal on the release of TGF-ß1. METHODS: Single-rooted human teeth were decoronated, and the canals were enlarged with a Peeso reamer. The samples were divided into biofilm and nonbiofilm groups. Subsequently, all the samples of both groups were flushed with 10 mL of each irrigant, namely, 1.5% sodium hypochlorite (NaOCl), 7% MA, 17% EDTA, and a combination of 1.5% NaOCl with 17% EDTA or 7% MA, for 10 minutes each. TGF-ß1 was estimated quantitatively using an enzyme-linked immunosorbent assay kit. RESULTS: TGF-ß1 release was lowest among the biofilm samples compared with nonbiofilm among all the groups. MA 7% with 1.5% NaOCl rendered higher amounts of growth factor release in contrast to the combination of 17% EDTA and 1.5% NaOCl in both the biofilm and nonbiofilm groups (P < .048). The nonbiofilm samples treated with 7% MA alone illustrated higher growth factor release compared with 17% EDTA only (P < .006), but there was no significant difference in growth factor release among the biofilm samples treated with 7% MA and 17% EDTA. CONCLUSIONS: Bacterial biofilms modified the release of TGF-ß1. MA 7% was observed to be significantly more efficacious than 17% EDTA in TGF-ß1 growth factor release from radicular dentin.

Effect of Different Concentrations of Sodium Hypochlorite on the Compressive Strength of Endodontically Treated Roots.

INTRODUCTION: The aim was to compare the compressive strength of dentin after irrigation with different concentrations of sodium hypochlorite (NaOCl). METHODS: A total of 259 extracted human tooth roots with no root caries or previous endodontic treatment were collected. They were sorted by size and length, and assigned to 7 groups (n = 37): negative control (no instrumentation, no irrigant), positive control (saline irrigant), 1%, 2.5%, 4%, 5.25%, and 10% NaOCl. A total of 13 mL NaOCl or saline (in 1-mL increments) was used per canal while being instrumented to #35 files (approximately 13 minutes). EDTAC (15%) was then used to remove the smear layer (2 minutes), followed by NaOCl as a final rinse. The roots were sectioned into 2-mm-thick disks and subjected to compression testing. RESULTS: There was a significant difference between the negative control group and all instrumented groups (P < .05). The positive control group was significantly different from the 5.25% group (P < .05) and had a low P value when compared with the 2.5% group and the other higher concentrations (P â‰… .1). When the NaOCl groups were compared with each other, there was a significant difference between 1% NaOCl and all higher concentrations (P < .05), but no significant difference when 2.5% NaOCl was compared with higher concentrations. CONCLUSION: A concentration of 1% NaOCl had the least effect on the compressive strength of dentin and this was significantly different from all higher concentrations tested. Therefore, the use of concentrations of NaOCl above 1% should be reconsidered.