Comparative evaluation of ethanol versus citric acid in removal of oil-based calcium hydroxide from the apical third of root canal system.

Objectives: To evaluate the effectiveness of ethanol compared to citric acid in the removal of oil-based calcium hydroxide from the apical third of the root canal system using passive ultrasonic irrigation. METHODS: The in vitro study was conducted from September to October 2021 at the dental clinics of the Aga Khan University Hospital, Karachi, and comprised single-rooted teeth that were selected from institutional bank of extracted teeth. They were randomly divided into group A having 70% ethanol + passive ultrasonic irrigation, group B 10% citric acid + passive ultrasonic irrigation, group C positive controls and group D negative controls. The specimens were sectioned at 1mm and 3mm from the apex and examined under a dental operating microscope. A single examiner scored the specimens on two different occasions. Data was analysed using SPSS 25. RESULTS: Of the 90 teeth, there were 40(44.4%) in each of the 2 experimental groups and 5(5.5%) in each of the 2 control groups. At 3mm apical sections, ethanol was significantly more effective in the removal of oil-based calcium hydroxide (p=0.01). However, at 1mm from the apex, there was no significant difference between the experimental groups (p=0.064). Intragroup comparison showed that for groups A and B, residual medicament at 1mm sections was significantly greater than at 3mm sections (p<0.001, p=0.003). CONCLUSIONS: Neither irrigant showed complete removal at 1mm and 3mm from the apex. However, at 3mm apical sections, 70% ethanol was significantly more effective compared to 10% citric acid.

Examining the Effects of Asiaticoside on Dental Pulp Stem Cell Viability and Proliferation: A Promising Approach to Root Canal Treatment.

AIM: This study aims to evaluate the impact of asiaticoside (AC) on the viability and proliferation of dental pulp stem cells (DPSCs), considering the known negative effects of routinely used intracanal medicaments. This evaluation will be compared with the outcomes from using traditional intracanal medicaments, specifically triple antibiotic paste (TAP) and calcium hydroxide [Ca(OH)2]. MATERIALS AND METHODS: The DPSCs were obtained from the third molars of an adult donor. The application of flow cytometry was employed to do a phenotypic analysis on DPSCs using CD90, CD73, CD105, CD34, CD14, and CD45 antibodies. The methylthiazol tetrazolium (MTT) assay was employed to assess cellular viability. The cells were treated with different concentrations of TAP and Ca(OH)2 (5, 2.5, 1, 0.5, and 0.25 mg/mL), along with AC (100, 50, 25, 12.5, and 6.25 µM). A cell proliferation rate was performed at 3, 5, and 7 days. RESULTS: The characterization of DPSCs was conducted by flow cytometry analysis, which verified the presence of mesenchymal cell surface antigen molecules (CD105, CD73, and CD90) and demonstrated the absence of hematopoietic markers (CD34, CD45, and CD14). Cells treated with concentrations over 0.5 mg/mL of TAP and Ca(OH)2 showed a notable reduction in cell viability in comparison to the untreated cells (p < 0.05). Additionally, the cells treated with different concentrations of AC 12.5, 6.25, 25, and 50 µM did not differ significantly from the untreated cells (p > 0.05). Nevertheless, cells treated with concentrations of 100 µM showed a significant reduction in viability compared to the untreated cells (p < 0.05). After a period of 7 days, it was noted that cells exposed to three different concentrations of AC (50, 25, and 12.5 µM) had a notable rise in cell density in comparison to TAP and Ca(OH)2 (p < 0.05). Furthermore, cells that were exposed to a concentration of 12.5 µM exhibited the highest cell density. CONCLUSION: The cellular viability of the AC-treated cells was superior to that of the TAP and Ca(OH)2-treated cells. Moreover, the AC with a concentration of 12.5 µM had the highest degree of proliferation. CLINICAL SIGNIFICANCE: This study underscores the importance of evaluating alternative root canal medicaments and their effects on DPSCs' growth and vitality. The findings on AC, particularly its influence on the survival and proliferation of DPSCs, offer valuable insights for its probable use as an intracanal medication. This research contributes to the ongoing efforts to identify safer and more effective intracanal treatments, which are crucial for enhancing patient outcomes in endodontic procedures. How to cite this article: Alazemi MJ, Badawi MF, Elbeltagy MG, et al. Examining the Effects of Asiaticoside on Dental Pulp Stem Cell Viability and Proliferation: A Promising Approach to Root Canal Treatment. J Contemp Dent Pract 2024;25(2):118-127.

Genotoxicity and oxidative stress induction by calcium hydroxide, calcium titanate or/and yttrium oxide nanoparticles in mice.

Intensive uses of Calcium hydroxide (Ca(OH)2NPs), calcium titanate (CaTiO3NPs) and yttrium oxide (Y2O3NPs) nanoparticles increase their environmental release and human exposure separately or together through contaminated air, water and food. However, too limited data are available on their genotoxicity. Therefore, this study explored the effect of Ca(OH)2NPs, CaTiO3NPs or/and Y2O3NPs administration on the genotoxicityand oxidative stress induction in mice hepatic tissue. Mice were orally administered Ca(OH)2NPs, CaTiO3NPs and Y2O3NPs separately or simultaneously together at a dose level of 50 mg/kg b.w. for two successive weeks (3 days per week). Marked induction of DNA damage noticed after oral administration of Ca(OH)2NPs or CaTiO3NPs alone together with high Ca(OH)2NPs induced reactive oxygen species (ROS) generation and a slight CaTiO3NPs induced ROS production were highly decreased after simultaneous coadministration of administration of Y2O3NPs with Ca(OH)2NPs and CaTiO3NPs up to the negative control level. Oral administration of Y2O3NPs alone also did not cause observable changes in the genomic DNA integrity and the ROS generation level compared to the negative control levels. Similarly, significant elevations in P53 gene expression and high reductions in Kras and HSP-70 genes expression were observed only after administration of Ca(OH)2NPs alone, while, remarkable increases in the Kras and HSP-70 genes expression and non-significant changes in p53 gene expression were noticed after administration of CaTiO3NPs and Y2O3NPs separately or simultaneously together with Ca(OH)2NPs. Conclusion: Ca(OH)2NPs exhibited the highest genotoxic effect through oxidative stress induction and disruption of apoptotic (p53 and Kras) and protective (HSP-70) genes expression. Slight DNA damage was noticed after CaTiO3NPs administration. However, administration of Y2O3NPs alone was non-genotoxic and coadministration of Y2O3NPs with Ca(OH)2NPs and CaTiO3NPs restored genomic DNA integrity and normal expression of apoptotic p53 and protective HSP-70 genes disrupted by Ca(OH)2NPs and CaTiO3NPs. Thus co-administration of Y2O3NPs with Ca(OH)2NPs and CaTiO3NPs is recommended to counter Ca(OH)2NPs and CaTiO3NPs induced genotoxicity and oxidative stress.

The Effects of Calcium Silicate- and Calcium Hydroxide-based Root Canal Sealers on Postoperative Pain: A Randomized Clinical Trial.

INTRODUCTION: This study aimed to compare the postoperative pain level changes resulting from using calcium silicate- (EndoSeal MTA) and calcium hydroxide-based (Sealapex) root canal sealers in mandibular first and second molar teeth with symptomatic apical periodontitis. METHODS: A total of 60 patients with symptomatic apical periodontitis in their lower molar teeth were randomly allocated into 2 groups according to sealer type (n = 30). Demographic data, including gender, age, and smoking habit, and preoperative pain measures were recorded. Root canal treatments were performed in a single visit. Postoperative pain measurements and analgesic intake were measured at 6, 12, 24, and 48 hours and after 3, 5, and 7 days using the visual analog scale. The data were statistically analyzed using a chi-squared test (to compare gender, age, smoking habit, analgesic intake, and sealer extrusion), the Mann-Whitney U test (to compare pain levels), Friedman tests (for the evaluations of the reduction in pain levels over time), and Spearman's correlation test (to analyze the relationships of age, gender, smoking habit factors with postoperative pain) (P = .05). RESULTS: The statistical analysis showed no significant differences between the groups in postoperative pain and analgesic intake at any of the time intervals evaluated (P > .05). CONCLUSIONS: Patients treated with calcium silicate- and calcium hydroxide-based root canal sealers experienced similar postoperative pain and no statistically significant differences were observed in analgesic intake.

Reparative Dentin Formation Following Dental Pulp Capping is Mediated by TNFR1 In Vivo.

INTRODUCTION: Tumor necrosis factor (TNF)-α is a pro-inflammatory cytokine that promotes biomineralization in vitro in dental pulp cells. However, the role of TNF-α-TNF receptor 1 (TNFR1) signaling in reparative dentin formation and related inflammatory pathways is not known. Therefore, the aim of this study was to evaluate the role of the TNF-α-TNFR1 axis in dental pulp repair following pulp capping in vivo. METHODS: Dental pulp repair response of genetically deficient TNF-α receptor-1 mice (TNFR1-/-; n = 20) was compared with that of C57Bl6 mice (wild type [WT]; n = 20). Pulp capping was performed with mineral trioxide aggregate on the mandibular first molars of mice. After 7 and 70 days, tissues were collected and stained with hematoxylin and eosin for histopathological and histometric evaluation, and assessed by the Brown and Brenn methods for histomicrobiological analysis and by immunohistochemistry to localize TNF-α, Runt-related transcription factor 2, Dentin Sialoprotein (DSP) and Osteopontin (OPN) expression. RESULTS: Compared with WT mice, TNFR1-/- mice showed significantly decreased reparative dentin formation with a lower mineralized tissue area (P < .0001). Unlike WT mice, TNFR1-/- mice also exhibited significant dental pulp necrosis, neutrophil recruitment, and apical periodontitis formation (P < .0001) without bacterial tissue invasion. TNFR1-/- animals further exhibited decreased TNF-α, DSP, and OPN expression (P < .0001), whereas Runt-related transcription factor 2 expression was unchanged (P > .05). CONCLUSION: The TNF-α-TNFR1 axis is involved in reparative dentin formation following dental pulp capping in vivo. Genetic ablation of TNFR1 modified the inflammatory process and inhibited the expression of the DSP and OPN mineralization proteins, which culminated in dental pulp necrosis and development of apical periodontitis.

A calcium hydroxide/oleic acid/phospholipid nanoparticle induced cancer cell apoptosis by the combination of intracellular calcium overload and lactic acidosis elimination.

Intracellular calcium ions (Ca2+) influence the proliferation-apoptosis balance, and lactic acidosis is an innate feature of a malignant tumor. In this study, a calcium hydroxide/oleic acid/phospholipid nanoparticle [CUR-Ca(OH)2-OA/PL NP] with lipase/pH dual responsive delivery of Ca2+ and curcumin (CUR) was developed for inducing cancer cell apoptosis by a combination of intracellular calcium overload and lactic acidosis elimination. The nanoparticle showed a core-shell structure with some good performance, including an adequate nano-size, negative charge, good blood circulation stability, and non-hemolysis. MDA-MB-231 breast cancer cells exhibited a higher lipase activity than A549 human lung adenocarcinoma cells and L929 mouse fibroblasts by fluorescence analysis. CUR-Ca(OH)2-OA/PL NPs were highly internalized by MDA-MB-231 cells, intracellularly released CUR and Ca2+, triggered the activation of caspase 3 and caspase 9, and caused apoptosis by intracellular calcium overload via a mitochondrial-mediated pathway. Lactic acid of 20 mM inhibited the apoptosis of MDA-MB-231 cells depending on the glucose insufficiency level, but this inhibition could be eliminated by CUR-Ca(OH)2-OA/PL NPs, leading to nearly complete apoptosis. Herein, CUR-Ca(OH)2-OA/PL NPs are a potential killer of cancer cells with high lipase activity by a combination of intracellular calcium overload and lactic acidosis elimination.

Effect of intracanal cryotherapy on the inflammatory cytokine, proteolytic enzyme levels and post-operative pain in teeth with asymptomatic apical periodontitis: A randomized clinical trial.

AIM: To investigate the changes in the biomarker levels related to inflammation and tissue destruction in the periapical exudate of mandibular pre-molar teeth with asymptomatic apical periodontitis after receiving intracanal cryotherapy, to compare cryotherapy and control groups in terms of analgesic intake, interappointment, and post-operative pain and evaluate the correlation between biomarker levels and interappointment pain. METHODOLOGY: Mandibular pre-molar teeth of 44 patients aged 18-35 years, diagnosed with asymptomatic apical periodontitis, were root canal treated in two visits (registered as NCT04798144). Baseline periapical exudate samples were obtained, and the patients were assigned to either control or intracanal cryotherapy group according to the final irrigation with distilled water either at room temperature or 2.5°C. The canals were dressed with calcium hydroxide. In the second visit, the calcium hydroxide was removed with passive ultrasonic irrigation, and the periapical exudate was sampled again. IL-1ß, IL-2, IL-6, IL-8, TNF-α, PGE2 and MMP-8 levels were determined with ELISA. Post-operative pain levels were recorded for 6 days following both visits using a visual analogue scale. Data were analysed using t-test, the Mann-Whitney U test and correlation tests. RESULTS: There was a significant correlation between the pain scores reported after first visit and IL-1ß and PGE2 levels (p < .05). IL-1ß, IL-2 and IL-6 levels showed no significant difference in the cryotherapy group (p > .05), while they significantly increased in the control group (p < .05). There was a decrease in IL-8, TNF-α, PGE2 and MMP-8 levels, however, the difference was not significant (p > .05). Pain scores were significantly lower in the cryotherapy group for the first 3 days (p < .05), except for 24th hours (p > .05). CONCLUSIONS: The positive correlation between interappointment pain and IL-1ß and PGE2 levels might indicate that these biomarker levels can be used to predict the severity of post-operative pain. Intracanal cryotherapy was effective in reducing post-operative pain in the short term in teeth with asymptomatic apical periodontitis. Cryotherapy prevented an increase in IL-1ß, IL-2 and IL-6 levels compared with the control group.

In vitro study on how photodynamic therapy and calcium hydroxide medication influence adhesive interface properties of glass-fiber posts to intraradicular dentin.

PURPOSE: This in vitro study evaluated the influence of antimicrobial photodynamic therapy (aPDT), using methylene blue (MB) as photosensitizer (PS) and calcium hydroxide (CH) as intracanal medication on adhesive bond strength, sealing, and integrity of the luting interface of glass-fiber posts to different thirds of endodontically treated root canal dentin. MATERIAL AND METHODS: 102 incisors were sorted into 6 groups: a negative control irrigated with deionized water; a positive control irrigated with deionized water and filled with CH; CH + MB 50 mg/L without laser radiation; CH + MB 100 mg/L without laser radiation; CH + MB 50 mg/L radiated by red laser; and CH + MB 100 mg/L radiated by red laser. Push-out bond strength (n = 8), adhesive interface sealing (n = 3), and volume and quantification of voids (n = 6) were assessed using a universal testing machine, confocal laser scanning microscope, and computerized microtomography, respectively. Scanning electron micrographs were obtained from representative samples to qualify the fracture patterns. Push-out bond strength and adhesive interface integrity data were subjected to 2-way ANOVA for repeated measures followed by Tukey's test (α = 0.05). Adhesive interface sealing was evaluated by the inter-examiner Kappa test and submitted to Kruskal-Wallis and Dunns tests (α = 0.05). RESULTS: Assessing the apical region, the positive control and MB100WA + Ca(OH)2 groups showed lower adhesive bond strength compared to the MB100A + Ca(OH)2 group (P < 0.05). The cervical third showed higher bond strength than the apical third for the positive control, MB50WA + Ca(OH)2, MB100WA + Ca(OH)2, and MB50A + Ca(OH)2 groups (P < 0.05). A prevalence of mixed failure was observed in all experimental groups. There were no statistically significant differences in adhesive interface sealing for any of the parameters assessed (P > 0.05). MB100WA + Ca(OH)2 and MB100A + Ca(OH)2 groups promoted a higher volume and quantification of voids compared to the negative control group evaluating the cervical third (P < 0.05). In general, there were no differences in the quantification of voids comparing the intraradicular thirds (P > 0.05), differently to the volume of voids in which, in general, the cervical third promoted higher values compared to the middle and apical thirds (P < 0.05). CONCLUSION: aPDT with methylene blue PS at 50 mg/L associated with calcium hydroxide as intracanal medication demonstrated satisfactory bond strength, sealing, and integrity of the adhesive interface at any intraradicular depth.

Effect of the timing of radiation therapy on the push-out strength of resin cement to root dentine.

This study investigated the effect of radiation timing on the bond strength of resin cement to intraradicular dentine. Fifty human teeth were distributed into 5 groups (n = 10): Control (nonirradiated teeth), Before-RCT (teeth irradiated before root canal treatment), After-CH (teeth irradiated after canal preparation and placement of calcium hydroxide intracanal dressing), After-RCT (teeth irradiated after completion of root canal treatment) and After-FPL (teeth irradiated after luting of a glass fibre post). Each tooth received 70 Gy irradiation. The roots were sectioned for push-out strength testing. After-RCT and After-FPL groups had significantly lower push-out strength than the control at the middle third (p < 0.05). Control and After-CH groups had a higher percentage of cohesive dentine failure. Radiotherapy after root canal obturation and post luting adversely affected the adhesiveness of resin cement to intraradicular dentine. Teeth irradiated before root canal treatment and after placement of calcium hydroxide had the best performance.

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.

Calcium hydroxide diffusion after agitation of endodontic irrigants: an ex vivo study

Aim: To compare the influence of two methods of agitation of endodontics irrigants, by diffusion of calcium hydroxide [Ca(OH)2] through the dentinal tubules, measuring the pH of the medium where they were kept. Methods: Twenty mandibular incisors were prepared using a WaveOne Gold Large file, in a reciprocating movement, and then divided into (n = 10): gutta-percha cone (GPC) or Easy Clean system (ECS) agitation of 1% sodium hypochlorite and 17% ethylenediaminetetraacetic acid. The specimens were filled with Ca(OH)2 paste, placed in flasks with 4 mL of deionized water, and stored in an incubator. The pH was read using a digital pH meter immediately after storage (T0), after 7 (T1), 14 (T2), 21 (T3), and 35 (T4) days. Results: Statistical difference between groups was observed regardless of the day pH was measured (p < 0.01). From T2 on, ECS presented higher pH values in comparison with GPC, with significant difference (p < 0.01). Conclusion: Agitation of endodontic irrigants with ECS enhances the Ca(OH)2 diffusion, providing higher pH values, from the 14th day on, when compared with GPC

Investigation of the effect of indirect pulp capping materials on dentin mineral density

Aim: To evaluate the potential of inducing mineral density changes of indirect pulp capping materials applied to demineralized dentin. Methods: A total of 50 cavities were prepared, 5 in each tooth, in extracted ten molars without caries, impacted or semi-embedded. The cavities were scanned by microcomputed tomography (µ-CT) after creating artificial caries by microcosm method (pre-treatment). Each cavity was subjected to one of 5 different experimental conditions: control (dental wax), conventional glass ionomer cement (Fuji IX GP Extra), resin-modified calcium silicate (TheraCal LC), resin-modified calcium hydroxide (Ultra-Blend Plus), MTA (MM-MTA) and the samples were kept under intrapulpal pressure using simulated body fluid for 45 days. Then, the second µ-CT scan was performed (post-treatment), and the change in dentin mineral density was calculated. Afterward, elemental mapping was performed on the dentinal surfaces adjacent to the pulp capping agents of 5 randomly selected samples using energy dispersive X-ray spectroscopy (EDS) apparatus attached to a scanning electron microscope (SEM). The Ca/P ratio by weight was calculated. Friedman test and Wilcoxon Signed Ranks test were used to analyze the data. Results: There was a significant increase in mineral density values of demineralized dentin after treatment for all material groups (p<0.05). Resin-modified calcium silicate had similar efficacy to MTA and conventional glass ionomer cement, but was superior to resin-modified calcium hydroxide in increasing the mineral density values of demineralized dentin. Conclusions: Demineralized dentin tissue that is still repairable can be effectively preserved using materials with remineralization capability

Light-curing of calcium hydroxide-based liners: pH analysis and calcium ion release / Fotoativação de forradores a base de hidróxido de cálcio: análise de pH e liberação de íons cálcio

Objective: Compare the pH values and calcium ion release of calcium hydroxide-based liner materials before and after light-curing. Material and Methods: The materials evaluated were: hydrox-cal white (HW), hydrox-cal dentin (HD), Biocal (BC) and UltraBlend Plus (UB). 120 samples of the liner materials were inserted into a PVC tube (n=15). The samples from HW+A, HD+A, BC+A and UB+A were subjected to photoactivation. The other groups HW+N, HD+N, BC+N and UB+N were only inserted in a glass tube with deionized water. The pH was measured 24 hours and 14 days after the inclusion of the samples with the aid of a pH meter. The calcium release was analyzed with the aid of an atomic absorption spectophotometer at 24h and 14 days. The results were submitted to the Shapiro-Wilk test, followed by ANOVA and Tukey test (p=0.05). Results: In 24h, the groups that were not light cured showed the highest pH values (p<0.05). In 14 days, BC+N and BC+A demonstrated the lowest pH values. The groups that were not light cured also showed higher calcium release values in 24h and 14 days (p<0.05). Conclusion: Photoactivation of calcium hydroxide-based liner materials negatively interferes with calcium ion release, as well as with pH.(AU)

Objetivo: Comparar os valores de pH e liberação de íons cálcio de materiais forradores à base de hidróxido de cálcio antes e depois da fotopolimerização. Material e métodos: Os materiais avaliados foram: Hidrox-cal branco (HW), Hidrox-cal dentina (HD), Biocal (BC) e UltraBlend Plus (UB). 120 amostras dos materiais de revestimento foram inseridas em um tubo de PVC (n=15). As amostras de HW +A, HD+A, BC+A e UB+A foram submetidas à fotoativação. Os demais grupos HW +N, HD+N, BC+N e UB+N foram inseridos apenas em um tubo de vidro com água deionizada. O pH foi medido 24 horas e 14 dias após a inclusão das amostras com o auxílio de um medidor de pH. A liberação de cálcio foi analisada com o auxílio de um espectrofotômetro de absorção atômica em 24h e 14 dias. Os resultados foram submetidos ao teste de Shapiro-Wilk, seguido de ANOVA e teste de Tukey (p=0,05). Resultados: Em 24h, os grupos não fotopolimerizados apresentaram os maiores valores de pH (p<0,05). Em 14 dias, BC+N e BC+A apresentaram os menores valores de pH. Os grupos não fotopolimerizados também apresentaram maiores valores de liberação de cálcio em 24h e 14 dias (p<0,05). Conclusão: A fotoativação de materiais de revestimento à base de hidróxido de cálcio interfere negativamente na liberação de íons cálcio e no pH (AU)

Pulpectomies with Iodoform Versus Calcium Hydroxide-Based Paste: A Preliminary Randomised Controlled Clinical Trial

ABSTRACT Objective: To compare clinical and radiographical pulpectomy outcomes in primary teeth filled with different pastes. Material and Methods: The sample included thirty-eight teeth indicated for pulpectomy due to irreversible pulp inflammation or necrosis from thirty patients (2 to 9 years old). The first appointment comprised chemomechanical preparation (2.5% sodium hypochlorite), smear layer removal (6% citric acid), intracanal dressing and temporary restoration. Seven days later, teeth were randomly assigned to filling with iodoform (IP) or calcium hydroxide with zinc oxide (CHZO) based pastes and temporarily restored. Final restoration (composite resin) occurred at the 3rd appointment. Data from baseline, 6 and 12 months were analysed using descriptive and inferential statistics (p≤0.05). Results: The overall frequency of success was 63.6% (n=21), with no significant difference between groups (IP=62.5% n=10; CHZO=64.7% n=11, p=0.59). Multiradicular teeth, overfilled canals and teeth whose coronal restoration have been lost were significantly associated with failure (p=0.01, p=0.04 and p<0.001, respectively). Conclusion: After 12 months, both pastes showed similar outcomes and can be used as good options for pulpectomies in primary teeth. Moreover, tooth location, extent of the root canal filling, and integrity of final restoration during the follow-up influenced the outcome of pulpectomies.

Detoxification of LTA by intracanal medication: analysis by macrophages proinflammatory cytokines production.

The aim of this study was to evaluate in vitro the effect of calcium hydroxide [Ca(OH)2], 2% chlorhexidine gel (CHX) on macrophages (RAW 264.7) to produce pro-inflammatory cytokines and nitric oxide after pretreatment with lipoteichoic acid (LTA) of Enterococcus faecalis. Forty-eight human single-rooted teeth were instrumented with R25.08 (RECIPROC) and sterilized by gamma irradiation. LTA was inoculated in the root canal of each specimen for 96 hours. Specimens were instrumented with 40.06 and 50.05 (RECIPROC) and medicated with: I) Pyrogen-free saline solution (SS); II) 2% CHX gel; III) Ca(OH)2 + SS; or IV) Ca(OH)2 + CHX for 14 days. Three samples (S) were performed of the root canal of each specimen at: S1) immediately after instrumentation; S2) after Ethylenediaminetetraacetic acid (EDTA); S3) after intracanal medication removal. Subsequent quantification of cytokines (IL-1ß, TNF-α, MIP-1α, IP-10, G-CSF and IL-6) by immunosorbent assay (ELISA) and nitric oxide by the Griess method was carried-out. Data were submitted to a normality test and then analyzed with one-way ANOVA and Tukey test with a significance level of 5% using GraphPad Prism 6. Ca(OH)2 + SS and Ca(OH)2 + CHX presented lower levels of TNF-α, TNF-α, IL-6, G-CSF and nitric oxide. Ca(OH)2 + SS was the most effective in reducing MIP-1α. CHX was effective in reducing IL-6 and G-CSF. Therefore, the combined intracanal medication of calcium hydroxide and chlorhexidine is effective in reducing the cytokines TNF-α, IL-1ß, IL-6, G-CSF and nitric oxide.

Response of dental pulp capped with calcium-silicate based material, calcium hydroxide and adhesive resin in rabbit teeth

Direct pulp capping induces a local inflammatory process. Several biomaterials have been used for this procedure. The aim of this study was to compare the dentinal bridge thickness using three different pulp capping biomaterials with the conventional technique (high speed diamond bur) or Er-Yag laser, 1 month after pulp effraction. Materials and Methods: Forty two Class V cavities were prepared on the buccal surface of 4 maxillary incisors and 2 mandibular incisors of New Zealand rabbits. Specimens were divided into 6 treatment groups. Teeth were treated with: In Group 1: Er-Yag laser and Biodentine® (Septodont), in Group 2: Er: Yag laser and calcium hydroxide (Dycal® Dentsply), in Group 3: Er: Yag laser and adhesive system (Prime& Bond® NT Dentsply), in Group 4: high speed diamond bur and Biodentine® (Septodont), in Group 5: high speed diamond bur and calcium hydroxide (Dycal® Dentsply), and in Group 6: high speed diamond bur and adhesive system (Prime& Bond® NT Dentsply). The preparation was done with copious irrigation. The animals were sacrificed at 30 days and the teeth were extracted and prepared for histological analysis. Results: In the group of « laser Er-Yag ¼, iatrogenic pulpal wounds treated with Biodentine® were covered with a thick hard tissue barrier after 1 month. The difference was not significant with the groups of Dycal® used with Er: Yag laser and high speed diamond bur. Prime& Bond® NT Dentsply specimens showed a thin dentinal bridge layer. Conclusion: At 1 month, Er-Yag laser proved to be useful with Biodentine® for direct pulp capping procedures

Comparison of the Physicochemical Properties, Antimicrobial Action, and Cytotoxicity of Ambroxol Hydrochloride, N-acetylcysteine, and Calcium Hydroxide Pastes.

OBJECTIVE: To evaluate the solubility, pH, antimicrobial action, and cytotoxicity of ambroxol hydrochloride (AMB), N-acetylcysteine (NAC), and calcium hydroxide (CH) pastes for use as intracanal medications. METHODS: Solubility was determined by micro-CT, based on the paste volume remaining after immersion in water for 7 days. pH was measured by immersing acrylic tubes containing the pastes in ultrapure water and then measuring pH after 3 hours, 3 days, and 7 days. Antimicrobial action against Enterococcus faecalis was assessed based on the percentage of living cells, using the live/dead staining method under confocal microscopy. Cytotoxicity was assessed based on the cell viability of L929 fibroblast-like cells after 6, 24, and 48 hours. Cytotoxicity data were compared using the ANOVA and Tukey tests, and the antimicrobial data were compared using the Kruskal-Wallis and Dunn tests. The significance level used was 5% (α=0.05). RESULTS: The solubility values for all the study groups were significantly different (P<0.05), where the highest values were for NAC, followed by AMB, and then CH. Likewise, the pH levels were all significantly different (P<0.05), where NAC and AMB levels were acidic, and CH levels were alkaline. The antimicrobial action of AMB was significantly higher than that of CH (P<0.05), and that of NAC was also higher than that of CH, albeit not significantly. AMB and NAC were more cytotoxic than CH, and higher dilutions of CH promoted higher cell viability levels than lower dilutions of the same paste (P<0.05). CONCLUSION: The NAC and AMB pastes were more soluble and cytotoxic than the CH paste and had acidic pH levels. The AMB paste displayed the highest antimicrobial action against Enterococcus faecalis biofilm.

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

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

A magnetic antibody-conjugated nano-system for selective delivery of Ca(OH)2 and taxotere in ovarian cancer cells.

An efficient strategy for cancer therapy is presented, in which a tumor mass is initially pretreated with calcium hydroxide, then treated with Taxotere (TXT). In this regard, an advanced delivery system based on iron oxide nanoparticles has been designed. The surface of nanoparticles was functionalized with sortilin (SORT-1, a human IgG1 monoclonal antibody) that specifically encodes caov-4 ovarian cancerous cells. Plasmonic heating of the incorporated gold nanoparticles in polyvinyl alcohol (PVA) has been exploited to control the release process of TXT. The in vitro, ex vivo and in vivo experiments have exhibited high efficacy of a seven-day pretreatment by Ca(OH)2 plus 14 days treatment program by Ca(OH)2@Fe3O4/PVA/Au-SORT nano-therapeutics, where more penetration ratio resulted in tumor growth inhibition by ca. 78.3%. As a result, due to showing high values of the anti-tumor properties and biosafety, the presented pretreatment strategy is suggested for more effective treatment on the aged tumors.

Antibacterial and anti-inflammatory efficacy of N-acetyl cysteine in endodontic treatment: a scoping review.

BACKGROUND: This scoping review systematically summarized the available evidence about the efficacy of N-acetyl cysteine (NAC) as an intracanal antibacterial and/or anti-inflammatory. METHODS: PubMed, Scopus, Web of Science, and Google scholar search engines/databases were searched up to February 2022 to retrieve relevant studies. The studies were evaluated for eligibility criteria, and identifying relevant studies. RESULTS: Out of 193 studies, 15 fulfilled the inclusion criteria and were processed for data extraction. Thirteen in vitro studies assessed antibacterial/antibiofilm efficacy of NAC, and reported good and promising efficacy: NAC was found as efficacious as the comparators (chlorhexidine, sodium hypochlorite, calcium hydroxide), or even showed higher efficacy. Regarding the anti-inflammatory efficacy of NAC, one in vitro study found it equivalent to, while one clinical trial revealed it more efficacious than calcium hydroxide. CONCLUSIONS: There is accumulating evidence on the anti-microbial and anti-inflammatory efficacy of NAC in context of endodontics. However, further clinical trials with robust methodology and objective and reliable clinical, biological and microbial outcomes are warranted to translate its use for clinical practice on humans.