Apical Sections Research Articles

Efficacy of irrigation activation methods in removal of bioceramic-based sealer in retreatment.

In cases where initial root canal therapy is unsuccessful, retreatment is the first treatment choice. However, when bioceramic-based sealers have been used in the initial treatment, their complete removal can be challenging. The objective of this study was to evaluate the efficacy of three final irrigation activation methods-conventional needle irrigation, passive ultrasonic activation, and EDDY activation-using a scanning electronic microscopy (SEM) to evaluate the removal of bioceramic-based sealers after retreatment. A total of 108 single-rooted teeth were prepared using ProTaper Next rotary files. The samples were obturated with either MTAFillapex or BioSerra (n = 54) and stored for 2weeks post-obturation. After the retreatment procedures, the teeth were divided into six groups (n = 18 per group) based on final irrigation activation method used. Group1:MTAFillapex-CNI, Group2:BioSerra-CNI, Group3:MTAFillapex-EDDY, Group4:Bioserra-EDDY, Group5:MTAFillapex-UltraX, Group6:Bioserra-UltraX. The roots were sectioned longitudinally, and the coronal, middle and apical parts were investigated under a SEM. The data were then statistically analysed. The EDDY activation technique proved significantly more effective in removing MTA Fillapex across all sections of the root canal (p < 0.001). In contrast, Ultra-X was more effective in removing Bioserra in the middle and apical sections (p = 0.003, p < 0.001). These findings suggest that activation procedures may be preferable for removing bioceramic-based root canal sealer.

Development and assessment of an intestinal tri-cellular model to investigate the pro/anti-inflammatory potential of digested foods

IntroductionImmunonutrition, defined as the potential of foods, nutrients and dietary patterns to modulate the immune system activity, has been proposed as a strategy to enhance the immune response in both metabolic and immune-mediated diseases. However, the anti-/pro-inflammatory role of foods and diets is far to be fully ascertained, and thus there is a continued needed for appropriate in vitro cell-culture models to investigate the role of foods in modulating cell-mediated inflammatory processes. This study aims to develop and test an in vitro tri-culture model, simulating the complexity of the intestinal tract and its multiple cell interactions.MethodsTo achieve this, the intestinal epithelial barrier was established by co-culturing human Caco-2 enterocyte-like and HT29-MTX-E12 mucus producing goblet-like colon cells, then adding human monocyte THP-1 cells to the basolateral compartment. The integrity and stability of the epithelial barrier were monitored and the inflammatory response of the model was assessed using various stressors at different concentrations, both individually and in combination (phorbol-12- myristate-13-acetate or PMA, and lipopolysaccharide or LPS), in terms of cytokines production. To test the model, different concentrations of in vitro digested broccoli (BD) were added to the apical section of the model.ResultsSupernatants from the basolateral compartment were collected and analyzed for cytokines production (IL-6, TNF-α, IL-12p70, IL-18 and IL-8) using automated ELISA (ELLA). Additionally, ZO-1 protein from the tight junctions of epithelial cells was analyzed by flow cytometry. The results indicated that 100 nM PMA added to the whole model for 20 h was the best stressor to simulate a mild-inflammatory status of the gut. Following treatment with BD, IL-6, TNF-α, IL-8 and IL-18 were significantly reduced compared to the control group, while ZO-1 expression increased at the lowest BD concentration.ConclusionsThese findings confirm the feasibility of the model for assessing the effects of food digesta on specific cytokines and permeability markers, representing a valuable strategy for investigating the role of foods in modulating the inflammatory response. The results obtained may support dietary strategies aimed at promoting wellbeing and preventing inflammatory-related metabolic diseases.

In vitro evaluation of dye penetration and dentin microhardness after laser irradiation using photon-induced photoacoustic streaming and shock wave enhanced emission photoacoustic streaming tips compared to ultrasonic activation

The purpose of this study was to compare the penetration of methylene blue (MB) dye after laser irradiation using PIPS (photon-induced photoacoustic streaming) and SWEEPS (shockwave enhanced emission photoacoustic streaming) methods compared to Passive ultrasonic irrigation (PUI) and to study their effect on dentin microhardness. A total of 44 single-rooted human teeth which were extracted for orthodontic or periodontal reasons were used. The teeth were decapitated to standardize roots to 12 mm in length. Canals were prepared up to size #30.6% and divided randomly into four groups (n = 11/group) according to the method of NaOCl activation: Group I: Er: YAG laser activation with PIPS tip; Group II: Er: YAG laser activation with SWEEPS tip; Group III: passive ultrasonic irrigation (PUI) and Group IV: conventional needle irrigation (CI). MB dye was injected then teeth were sectioned horizontally into coronal, middle and apical sections. Penetration depth/area percentages were measured using stereomicroscopy. Coronal specimens were further subjected to Vickers microhardness testing. Data were statistically analyzed. SWEEPS and PIPS activation methods provided higher dye penetration depth and area percentages compared to PUI with no statistically significant differences between all test groups. However, all test groups showed statistically significant differences with the CI (control) group. SWEEPS activation provided higher microhardness values with statistically significant differences with the other groups. Laser irrigant activation using PIPS and SWEEPS is comparable to PUI concerning MB dye penetration. However, SWEEPS preserved dentin microhardness significantly which can be beneficial for the long-term prognosis of root canal treated teeth.

Comparing the Efficacy of XP-endo Finisher with Irrigation Activation Methods on Sealer Penetration: An in Vitro Confocal Laser Scanning Microscopy Study

Aim: The irrigation method is effective on the dentinal tubule penetration (DTP) of endodontic pastes, which is important for treatment outcome. The purpose of this study was to compare the effect of different irrigation techniques on the DTP of bioceramic endodontic paste with CLSM. Materials and Methods: A total of 52 mandibular premolar root canals were shaped with the ProTaper Next files and were divided randomly into four experimental groups ( n = 13) according to the final irrigation method with 17% EDTA and 5.25% NaOCl as follows: Group 1: Conventional needle irrigation (CNI), Group 2: sonic activation (SA), Group 3: passive ultrasonic activation (PUA), Group 4: XP-endo Finisher (XPF). After final irrigation, root canals were obturated with a bioceramic sealer labeled with the fluorescent dye. The roots were sectioned horizontally at three different levels, and 1 ± 0.1 mm thick sections were obtained to examine under CLSM. The penetration area (PA), maximum tubule penetration (MTP), and the percentage of penetration (PP) values were statistically evaluated with the two-way repeated measurements ANOVA test. The Tukey (HSD) test was carried out for intergroup comparisons ( p &lt; .01). The relationship between the MTP, PP, and PA at each root level was evaluated using Pearson’s correlation test. Results: In the middle sections, the penetration area of the sealer was higher in the SA group (7.120 ± 1.470) compared to the other groups ( p &lt; .01). Penetration area was higher in the XPF group (11.830 ± 1.370) in the coronal section compared to CNI (7.034 ± 0.926) ( p &lt; .01). No significant difference was observed between the MTP and PP values of the experimental groups ( p &gt; .01). DTP of sealer was statistically similar for each irrigation method in the apical section. The coronal regions showed higher DTP values compared with the apical regions. There was a linear relationship between the PA and MTP values at all root levels of experimental groups ( p &lt; .05). The linear relationship between the PA and PP was not significant in the XP group ( p &gt; .05). Conclusion: The penetration area of SA was larger than others in the middle section, and XPF was superior to CNI in the coronal section. DTP of the sealer in the apical regions was lower than in the coronal regions.

Comparing Sectional and Total Dentin Bond Strengths of Three Endodontic Sealers after Using the Single-cone Obturation Technique: An In Vitro Study.

This study aimed to investigate and compare the total and sectional bond strengths of three endodontic sealers when used with the single-cone obturation technique. Forty-five human maxillary central incisors were prepared and divided into three groups according to the type of endodontic sealer: Group I (Gutta-percha/AH Plus Jet), group II (Gutta-percha/GuttaFlow 2), and group III (RealSeal/RealSeal SE). All canals were filled with the single-cone technique. Roots were sectioned and scanning electron microscope (SEM) analysis was performed on randomly selected samples from each group to assess the root canal filling interfaces. A root section from each root level was subjected to a push-out test. The sectional and total bond strengths were analyzed, then the failure modes were investigated. Statistical analysis was performed using one-way analysis of variance (ANOVA) and Tukey's test, and alpha was set at 0.05. Significant differences in bond strength values were observed (p < 0.05), with RealSeal SE demonstrating the highest bond strength, particularly in the middle and apical root regions. On the contrary, GuttaFlow 2 exhibited the lowest bond strength. Cohesive failure modes were more common for AH Plus Jet and GuttaFlow 2, while RealSeal SE showed cohesive and adhesive failures. The SEM analysis revealed that each sealer exhibited different levels of adaptability to dentin and core material. RealSeal SE and AH Plus Jet showed superior bond strength compared to GuttaFlow 2 when the single-cone obturation technique was used. The apical root sections exhibited the highest bond strength for all sealers, except for AH Plus Jet, which showed a higher bond strength in the coronal root sections. The current findings could guide dental professionals in choosing the most appropriate sealer for the single-cone obturation technique, potentially leading to more effective obturation procedures, especially for teeth requiring post and core restoration. How to cite this article: El Sayed M. Comparing Sectional and Total Dentin Bond Strengths of Three Endodontic Sealers after Using the Single-cone Obturation Technique: An In Vtro Study. J Contemp Dent Pract 2024;25(10):976-982.

Assessment of the bypass of obturation materials beyond fractured instruments after using different obturation techniques in simulated curved canals (An in-vitro study).

This study evaluated the extent to which obturation materials bypass fractured endodontic instruments positioned in the middle and apical thirds of severely curved simulated root canals using different obturation techniques. Sixty resin blocks with simulated root canals were used, each with a 50° curvature, a 6.5 mm radius of curvature, and a length of 16.5 mm, prepared to an ISO #15 diameter and taper. Canals were shaped using ProTaper Universal files (Dentsply Maillefer) attached to an X-smart Plus endo motor (Dentsply), set at 3.5 Ncm torque and 250 rpm, up to size S2 at working length. To simulate fractures, F2 and F3 files were weakened 3 mm from the tip, then twisted to break in the apical and middle sections of the canal, respectively. All samples were sealed with GuttaFlow 2 and divided into three groups (n = 20/group) according to obturation technique: A) single cone, B) lateral condensation with a rotary spreader, and C) softcore obturators. Each group was then divided into two subgroups (n = 10) based on the instrument fracture location (1 = apical, 2 = middle). The linear intrusion of obturation materials through the fractured instruments was measured using ImageJ software and analyzed statistically with ANOVA, Tukey tests, and independent t-tests, with significance set at p<0.05. Material bypass in group B1 (3.27 ± 0.63 mm) was significantly greater than in group A1 (2.39 ± 0.44 mm) and group C1 (2.91 ± 0.77 mm). In group C2, bypass (5.76 ± 0.64 mm) was significantly higher than in group A2 (3.82 ± 0.2 mm) and group B2 (2.27 ± 0.96 mm). Additionally, bypass in group A2 was greater than in group B2, and group B1 had more bypass than B2, while group C2 exceeded C1. The lateral condensation technique with a rotary spreader and softcore obturators increased the bypass of obturation materials through fractured instruments in simulated curved canals. These techniques may thus enhance material flow in endodontic procedures involving instrument fractures.

Comparative Evaluation of Crack Propagation During Root Canal Preparation in Primary Molar with Manual Instrumentation, ProTaper Universal and ProTaper Next Rotary File Systems: An in vitro Study.

Root canal preparation with rotary files causes dentinal cracks in root canals of primary teeth affecting their longevity. Nickel-titanium rotary files have been widely used for root canal preparation in primary teeth. The present study compared occurrence of dentinal microcracks in root canals of extracted primary molar teeth prepared using Hedstrom (H) files, ProTaper Universal rotary files, and ProTaper Next rotary file systems. In this in vitro experimental study, 80 primary molar mesial root canals were randomly divided into four groups of 20 canals each (n=20). Group I was prepared with H files. Group II was prepared with ProTaper Universal rotary files using shaping files SX and S2. Group III was instrumented with ProTaper Next rotary files X1 and X2 while Group IV was left unprepared and served as control. Roots were stained with 1% methylene blue solution and sectioned perpendicular to the long axis at 2mm, 4mm, and 6mm from the apical foramen. Slices obtained were examined under the stereomicroscope. Data obtained were subjected to statistical analysis using chi square tests. Dentinal microcracks were observed in groups prepared using H files, ProTaper Universal, and ProTaper Next rotary files. Highest percentage of cracked root canals (20%) was seen in Group I, prepared by H files. These cracks were complete in nature, found in apical sections and statistically significant (p= 0.016). Group III prepared with ProTaper Next showed 10% dentinal cracks, followed by ProTaper Universal group with 5% cracked root canals. H files may be considered more aggressive at apical third due to complete cracks produced.

Effect of Cold Plasma on the Penetration Depth of AH26 and Beta Resin Sealers in Dentinal Tubules.

The creation of a proper seal of the root canal with canal-filling materials, such as gutta-percha and sealer, is one of the essential factors in the success of root canal treatment. In addition, the penetration depth of the sealer is one of the influential factors in creating a proper seal, which improves the sealing ability of the canal and the burial of microorganisms. This study aimed to investigate the effect of cold atmospheric plasma on the depth of tubular penetration of two types of resin sealer: AH26 and Beta RCS sealers. In this experimental study, thirty-two premolar teeth with single root and single canal were selected as samples and after cutting their crowns from the apex distance of 15mm, the canals were prepared with rotary files. Samples were divided into four groups of eight, according to the type of sealer and plasma application: AH26 sealer (AH), plasma+AH26 sealer (PAH), Beta RCS sealer (Beta), and plasma+Beta RCS sealer (PBeta). The cold lateral condensation technique was used for the obturation of canals. The maximum penetration depth and the percentage of sealer penetration were obtained from microscopic images at three coronal, middle, and apical sections. Due to the non-normal distribution of data, the Mann-Whitney U test was used for statistical analysis (p< 0.05). No significant difference was observed between the study groups in the penetration percentage and maximum penetration depth of AH and Beta in the presence and absence of plasma. However, in the coronal section, the depth of maximum sealer penetration was significantly higher in the AH group than in the Beta group (p< 0.05). The use of plasma did not affect the maximum penetration depth and penetration percentage of AH26 sealer and Beta RCS sealer.

Conservative Management of Horizontal Root Fracture: ACase Report.

In cases where permanent teeth have closed apices and completely erupted roots, the probability of root fractures is increased due to the stable support given by the adjacent bone and periodontal tissues. Fractures have the potential to affect several dental structures, including the pulp, dentin, cementum, bone, and periodontal tissues. In cases of horizontal root fractures (HRF), the apical section typically maintains vitality; however, the present case presented an unusual apex necrosis. Given the patient's age and tooth stability, traditional apical surgery was deemed inappropriate. Instead, a conservative treatment approach was chosen to preserve the tooth. This case report details the management and a 2-year follow-up of a maxillary central incisor exhibiting a HRF and apical necrosis, successfully addressed through the application of Mineral Trioxide Aggregate (MTA) in the both apical and coronal segments. Using MTA prevented apical surgery in cases of apex necrosis accompanied by HRF.

Improving Propagation Efficiency of Eucalyptus cloeziana ‘Chuanlinzhen 7523’ by Optimizing Explants and Proliferation Medium

Eucalyptus cloeziana is an important, fast-growing, precious timber species in southern China, with tissue culture being the primary method for its propagation. However, the declining proliferation coefficient of adventitious shoots with multi-generation culture is a major constraint on its rapid propagation. This study aims to address this issue through the selection of suitable explants and optimizing the plant growth regulators’ formulation during the process of shoot proliferation. In this study, we cut shoots from the 21st generation of the tissue-cultured seedlings of ‘Chuanlinzhen 7523’ into apical, middle, and basal sections, and we measured their content of endogenous hormones. The proliferation coefficient (PC) and growth coefficient (GC) of explants under different concentrations of plant growth regulators were analyzed and ranked using the PCA method. The results indicated that the shoot basal sections were the best for proliferation when treated with 0.40 mg/L BAP (6-benzylaminopurine), 0.20 mg/L NAA (naphthaleneacetic acid), and 0.20 mg/L TDZ (thidiazuron), yielding a PC of 4.7 and a GC of 4.1. These basal sections ranked first with a rooting rate of up to 80%. When the rooted plantlets were acclimatized in the nursery, a survival rate of 100% was achieved. This protocol—from proliferation to acclimation—effectively improves the propagation efficiency of E. cloeziana ‘Chuanlinzhen 7523’ after multi-generation propagation.

In Vitro Microscopical and Microbiological Assessment of the Sealing Ability of Calcium Silicate-Based Root Canal Sealers.

This in vitro study evaluated the sealing ability and microleakage of calcium silicate-based sealers compared to an epoxy resin-based sealer. One hundred twenty-five roots from anterior teeth were chemo-mechanically prepared and divided into four groups: AH Plus (AH), ProRoot MTA (PR), Medcem MTA (MC), and Total Fill BC Sealer/BC-coated gutta-percha (TF); n = 30. Confocal laser scanning microscopy was used to measure sealer penetration at three horizontal levels in 10 roots per group, while glucose leakage over 30 days was assessed in 20 roots. A lateral compaction technique was used for most groups, except for TF, which employed a single-cone method. Data were analyzed using Python with a Kruskal-Wallis test and Dunn's post hoc test. TF showed significantly greater penetration in the coronal and middle sections, while PR had the least penetration in the apical section. PR exhibited the highest canal circumference penetration, especially compared to MC and TF. Glucose leakage increased over time in all groups, with TF showing the highest permeability after 30 days. Overall, calcium silicate-based sealers PR, MC, and TF performed similarly to the epoxy resin standard AH, with all groups exhibiting decreasing penetration from coronal to apical and increased leakage over time.

Comparative Evaluation Of The Effect Of Different Chelating Agents On The Push-Out Bond Strength Of A Bioceramic Sealer: An In-Vitro Study

Aim: This study aimed to assess how the push out bond strength of a bioceramic sealer (Meta CeraSeal) is affected by three different chelating agents: 17% EDTA, 7% Maleic acid, and 5% Pentetic acid. Methodology: 60 mandibular premolars were shaped using Pro Taper Gold rotary file upto size F2. The canals were irrigated with 2ml of 5.25% sodium hypochlorite (NaOCl) between instrumentation and then the NaOCl was removed by rinsing with five milliliters of distilled water.. The 60 specimens were divided into 4 groups of 15 each, in a random manner, depending on the final irrigating solution: Group 1 (n=15): 17% EDTA,Group 2 (n=15): 7% Maleic acid,Group 3 (n=15): 5% Pentetic acid and Group 4 (n=15): 0.9% Saline. The canals were obturated with Meta CeraSeal coated gutta percha using single cone technique. Access to cavities were sealed and the specimens were sectioned to obtain three horizontal sections at distances of 12, 6, and 2 mm from the apex (coronal, middle, and apical root sections, respectively). A universal testing machine was used to apply the push-out test. Results: The push out bond strength was significantly higher for 5% Pentetic acid as compared to 17% EDTA and 7% Maleic acid (p&lt;0.05). Also, the apical third exhibited the lowest push out bond strength value in all the groups. Conclusion: Within the limitations of the study, it can be concluded that, in comparison to the other tested groups, 5% pentetic acid has higher potential to facilitate the bonding of the bioceramic sealer Meta CeraSeal to root dentin

Coexpression Regulation of New and Ancient Genes in the Dynamic Transcriptome Landscape of Stem and Rhizome Development in "Bainianzhe"-An Ancient Chinese Sugarcane Variety Ratooned for Nearly 300 Years.

The sucrose yield in sugarcane largely depends on stem morphology, including length, diameter and sugar content, making sugarcane stem a key trait in breeding. The "Bainianzhe" variety from Songxi County, Fujian Province, possesses both aerial stems and rhizomes, providing a unique model for studying stem development. We performed a spatiotemporal transcriptomic analysis of the base, middle and apical sections of both aerial stems and rhizomes. The analysis categorized transcriptomes by developmental stage-base, middle and apical-rather than environmental differences. Apical segments were enriched with genes related to cell proliferation, while base segments were linked to senescence and fibrosis. Gene regulatory networks revealed key TFs involved in stem development. Orphan genes may be involved in rhizome development through coexpression networks. Plant hormones, especially genes involved in ABA and GAs synthesis, were highly expressed in rhizomes. Thiamine-related genes were also more prevalent in rhizomes. Furthermore, the apical segments of rhizomes enriched in photosynthesis-related genes suggest adaptations to light exposure. Low average temperatures in Songxi have led to unique cold acclimation in Bainianzhe, with rhizomes showing higher expression of genes linked to unsaturated fatty acid synthesis and cold-responsive calcium signalling. This indicates that rhizomes may have enhanced cold tolerance, aiding in the plant's overwintering success.

Antithrombotic activity of Punica granatum, L (Pomegranate): Experimental investigation and exploration of its mechanism of action on primary and secondary hemostasis in vitro and ex vivo

Hemostasis is the physiological process that stops bleeding by forming a thrombus (or blood clot). However, the inappropriate formation of a thrombus can constitute a pathophysiological event involving the same steps as those of hemostasis. Despite some adverse effects, antithrombotic therapy remains an effective means in the prevention and treatment of thrombotic diseases. In this regard, scientific research aimed at discovering new remedies of natural origin is particularly active.This study aims to evaluate the antithrombotic activity of the aqueous extract of Punica granatum peels in vivo. To understand the mechanism of action of this activity, we will investigate primary and secondary hemostasis in vitro and ex vivo. Furthermore, we will examine its antioxidant activity, toxicity, and phytochemical composition to identify the molecules responsible for the observed effects.The antithrombotic activity is assessed in vivo using the acute pulmonary thromboembolism model in mouse. Thrombosis is induced by injecting the thrombogenic solution (epinephrine + collagen) into the lateral caudal vein. Platelet aggregation, both in vitro and ex vivo, is performed on washed platelets isolated by centrifugation from rat blood. The platelet suspension is pre-incubated with the extract for 1 min. Aggregation is triggered by adding the following agonists: ADP, thrombin, collagen, and arachidonic acid. The bleeding time is measured in the absence and presence of the extract following an apical section of the mouse tail. This time corresponds to the duration of flow between the first and last drops of blood. To evaluate plasma coagulation, activated partial thromboplastin time (aPTT) and prothrombin time (PT) were measured under conditions both with and without the extract, using appropriate reagents. Acute toxicity is conducted by administering a single oral dose of the extract to mice (5 and 10 g kg-1). Possible changes in animal behavior are observed for fifteen days. The identification of polyphenols and flavonoids is performed by High Performance Liquid Chromatography (HPLC).The results obtained show that P. granatum exerted a significant preventive antithrombotic action (80 % protection) in mice. Furthermore, the extract inhibited platelet aggregation induced in vitro by all agonists in a dose-dependent manner, prolonged bleeding time, and coagulation times in rats. The results of the ex vivo study in rats confirmed these effects. We also noted that the extract did not exhibit toxicity following administration, and HPLC analysis revealed a richness of polyphenols and flavonoids in the extract.P. granatum exhibited an interesting antithrombotic activity, which could be attributed to its antiplatelet and anticoagulant actions. The phytochemical compounds identified in this extract could, at least in part, be responsible for these effects. Therefore, the demonstrated activities of this plant on hemostasis could lead to the development of more effective remedies and represent a means of prevention against thrombotic events.

A Comparison of Two Fluorescent Stains for the Evaluation of Bioceramic Sealer Penetration into the Tubular Dentine Using Confocal Microscopy

This study aimed to compare the percentage of bioceramic sealer penetration and maximum penetration sealer depending on the fluorescent staining method when evaluated with confocal laser scanning microscopy (CLSM). In total, 42 single-rooted premolars were instrumented. Two groups of 20 teeth each were filled using the single cone technique. TotalFill BC Sealer® mixed with Rhodamine B was used for the first group and TotalFill BC Sealer® mixed with Fluo-3 for the second group. Two teeth made up the control group. All teeth were sectioned at 3 and 6 mm from the apex and were analyzed with CLSM. The canal perimeter where the tubular penetration happened and the maximum penetration of each sample were calculated. There were no significant differences between the two groups in either the apical or medial sections. In terms of maximum penetration, Rhodamine B had greater tubular penetration in the apical sections, and it had similar results to Fluo-3 in the medial sections. TotalFill BC Sealer® has a higher tubular penetration in the medial slices than in the apical slices regardless of the fluorescent stain used. Rhodamine B has higher results than Fluo-3 in terms of the percentage of sealer penetration and maximum penetration.

Cochlear Implantation: Long-Term Effect of Early Activation on Electrode Impedance.

Objectives: The growing adoption of cochlear implants (CIs) necessitates understanding the factors influencing long-term performance and improved outcomes. This work investigated the long-term effect of early activation of CIs on electrode impedance in a large sample of CI users at different time points. Methods: A retrospective study on 915 ears from CI patients who were implanted between 2015 and 2020. According to their CI audio processor activation time, the patients were categorized into early activation (activated 1 day after surgery, n = 481) and classical activation (activated 4 weeks after surgery, n = 434) groups. Then, the impact of the activation times on the electrode impedance values, along the electrode array contacts, at different time points up to two years was studied and analyzed. Results: The early activation group demonstrated lower impedance values across all the electrode array sections compared to the classical activation at 1 month, 1 year, and 2 years post-implantation. At 1 month, early activation was associated with a reduction of 0.34 kΩ, 0.46 kΩ, and 0.37 kΩ in the apical, middle, and basal sections, respectively. These differences persisted at subsequent intervals. Conclusions: Early activation leads to sustained reductions in the electrode impedance compared to classical activation (CA), suggesting that earlier activation might positively affect long-term CI outcomes.

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

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

FEATURES OF MYOCARDIAL DEFORMATION PROPERTIES IN RELATION TO LEFT VENTRICULAR REMODELING TYPES IN PATIENTS WITH ARTERIAL HYPERTENSION

Objective: to determine the features of myocardial deformation properties in relation to left ventricular (LV) remodeling types in patients with arterial hypertension (AH). Design and method: The study included 62 patients of both sexes, with I–III degrees AH (ESC/ESH, 2018), who are undergoing outpatient treatment at the Republican Specialized Scientific and Practical Medical Center of Cardiology. The average age of patients was 53.1 ± 11.3 years, and the average duration of AH was 6.7 ± 6.5 years. Speckle-tracking EchoCG was performed to obtain an objective and quantitative assessment of global and regional myocardial function using SIEMENS's ACUSON x700 PV 2.0 system. Deformation properties of the LV myocardium were analyzed using the TOMTEC-ARENA Software system (TTA2.40.00). Among parameters for assessing longitudinal deformation of the LV we selected: global longitudinal strain -GLS (%); Strain Rate-SR (s-1). To study the segmental LV contractility, we analyzed the apical 4-chamber, 3-chamber, and 2-chamber section, the LV section along the short axis at the level of the mitral valve cusps, papillary muscles, and apex. Results are presented as M±SD. Results: The examined patient sample revealed three groups of LV geometric models: group I, n=27 (45.3%) patients with normal geometry; group II, n=27 (45.3%) patients with concentric remodeling; group III, n=8 (12.9%) patients with concentric hypertrophy. The absolute GLS values of the LV were: in group I - 20.0 ± 2.95%, in group II - 15.2 ± 2.99%, and in group III - 13.5 ± 1.87%. Inter-group analysis revealed that in the group with normal geometry, myocardial deformation properties of the LV were not impaired compared to II and III groups, as indicated by the GLS value within the normal range in group I patients (p &lt; 0.001). The lowest values of LV deformation were found in the group with concentric geometry, possibly influenced by factors such as the degree of hypertrophy, the presence of fibrosis in the myocardium, and diastolic dysfunction of the LV. Conclusions: Thus, in patients with AH and the presence of concentric hypertrophy, significant impairments in myocardial deformation properties of the LV are formed.

Comparison of Push-Out Bond Strengths of Different Fiber Post Systems Bonded with Resin Cement

Aim: This study compares the push-out bond strengths of 3 different fiber post systems bonded with resin cement to root canal dentin. Material and Methods: The study used 15 extracted single-rooted mandibular canine teeth. After the endodontic treatment of the teeth, they were randomly divided into three groups to apply different post-systems (n=5). Reforpost glass-fiber, Polydentia glass-fiber, and AAA Transparent fiber post systems were used in this study. The posts have adhered to the root canal with Panavia F2.0. A total of 6 slices of 1 mm thickness in the transversal direction were obtained, two from each of the coronal, middle, and apical sections of the prepared samples. The push-out test was performed from apical to coronal at a 0.5 mm/min speed. ANOVA and Tukey HSD tests were used for statistical analysis (p&lt;0.05). Results: The highest push-out binding values were observed in Polydentia (5.04±0.54); the lowest was seen in Reforpost (1.5±1.03). There was no statistical difference between the push-out binding values of the samples' apical, middle, and coronal regions for Reforpost and Transparent groups. In Polydentia group, the push-out binding values of the coronal region samples were significantly higher than those in the middle region. When the post groups were compared, the difference between the push-out binding values of all groups was statistically significant. Conclusion: The surface properties of the posts can affect the push-out bonding values. Polydentia showed the highest push-out binding values. In addition, the push-out attachment values of the posts may vary in different root canal regions.

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

AimAssessment 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. MethodSixty 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. ResultsThe 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. ConclusionBio-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.