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BACKGROUND: Calcium hydroxide [Ca(OH)2] is widely accepted as a biocompatible interappointment intracanal medicament. This study aimed to analyze the efficacy of Ca(OH)2 placement into the C-shaped canal system of mandibular second molars using the syringe method with and without lentulo spiral utilizing micro-computed tomography (micro-CT). METHODS: Twenty-four extracted mandibular second molars were instrumented and classified into C-shaped floors (n = 12) and non-C-shaped floors (n = 12). Both groups were placed with Ca(OH)2 using the syringe system, then all teeth were scanned and cleaned, and placed with Ca(OH)2 again but with the syringe system followed by lentulo spiral and rescanned. The specimens were scanned using micro-CT to analyze the volume, volume percentage, uncontacted surface area, and uncontacted surface area percentage of Ca(OH)2 with the two delivery methods in the entire canal and at the apical 4 mm of the canal. Mann-Whitney test and Wilcoxon signed-rank test were used to determine the statistical differences among the groups. RESULTS: Syringe administration used in conjunction with lentulo spiral presented lower uncontacted surface area, a lower percentage of uncontacted surface area, larger volume, and a higher percentage of volume than syringe without lentulo spiral (P < 0.05). There was no significant difference between the C-shaped floor group and the non-C-shaped floor group (P > 0.05) in the Ca(OH)2 uncontacted surface area, volume, and percentages at different regions of canals and among different delivery techniques groups. CONCLUSIONS: The lentulo spiral and syringe technique combination can increase the volume and contacted surface area of Ca(OH)2 in the C-shaped canal system of mandibular second molars.
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Hidróxido de Cálcio , Dente Molar , Humanos , Microtomografia por Raio-X , Hidróxido de Cálcio/uso terapêutico , Dente Molar/diagnóstico por imagem , Cavidade Pulpar/diagnóstico por imagemRESUMO
As a highly crystalline and renewable natural polymer nanomaterial, chitin nanocrystals (ChNCs) have attracted intense interest in the biomedical field. The structure of a ChNC is composed of an acetylglucosamine unit containing two hydroxyl groups and an acetyl group. The acetyl group can be converted to the active amino group through deacetylation, which is under the condition of maintaining the rod-like morphology and high crystalline property and is beneficial for the following modification and potential application. We investigated the relationship between different treatments and varied crystallinities of the modified ChNC, which obtained surface amino groups and aldehyde groups and retained high crystallinity. The natural biomolecules were covalently immobilized on the surface of the ChNC. The etherification was performed based on the hydroxyl groups. Based on the amino groups and the aldehyde groups, the carboxyamine and Knoevenagel condensation reactions were realized on ChNCs. Finally, natural biomolecule-modified ChNCs showed no or low cytotoxicity, antibacterial properties, and high antioxidant properties, which extended their potential biomedical applications.
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Quitina , Nanopartículas , Quitina/química , Polímeros , Antioxidantes/farmacologia , Nanopartículas/químicaRESUMO
BACKGROUND: Exopolysaccharides (EPS) are essential constituents of the extracellular matrix within oral biofilms and are significantly influenced by the local microenvironment. This study aimed to investigate the impact of two distinct antimicrobial agents, DJK-5 and chlorhexidine (CHX), on the EPS volume and pH levels in oral biofilms. METHODS: Oral biofilms obtained from two donors were cultured on hydroxyapatite discs for durations of 3 days, 1 week, 2 weeks, 3 weeks, and 4 weeks. Subsequently, these biofilms were subjected to treatment with 10 µg/mL DJK-5 or 2% CHX for 3 min. The impact of these antimicrobial treatments on factors such as the proportion of dead bacterial, in situ pH, and EPS volume within the biofilms was assessed using corresponding fluorescent probes. The examination was carried out utilizing confocal laser scanning microscopy, and the resulting images were analyzed with a focus on the upper and lower layers of the biofilm, respectively. RESULTS: DJK-5 exhibited a more potent bactericidal effect compared to CHX across the 3-day to 4-week duration of the biofilm (P < 0.05). The biofilms were acidic, with the upper layer being less acidic than the lower layer (P < 0.05). Both antimicrobial agents increased the pH, but DJK-5 had a greater effect than CHX (P < 0.05). The volume of EPS was significantly lower in DJK-5 treated biofilms compared to that of CHX, regardless of age or layer (P < 0.05). CONCLUSION: DJK-5 exhibited superior effectiveness in reducing viable bacteria and EPS volume, as well as in raising extracellular pH, as compared to chlorhexidine.
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Biofilmes , Clorexidina , Humanos , Clorexidina/farmacologia , Durapatita , Antibacterianos/farmacologia , Concentração de Íons de HidrogênioRESUMO
BACKGROUND: Bioceramic cements have been widely used in endodontic treatment. This study aimed to compare the microhardness, elastic modulus, internal microstructure and chemical compositions of Biodentine, WMTA, ERRM Putty, iRoot FS and IRM after exposure to PBS, butyric acid, and butyric acid followed by PBS. METHODS: Specimens of each material were prepared and randomly divided into 5 subgroups (n = 5): subgroup A: PBS (pH = 7.4) for 4 days, subgroup B: PBS (pH = 7.4) for 14 days, subgroup C: butyric acid (pH = 5.4) for 4 days, subgroup D: butyric acid (pH = 5.4) for 14 days, subgroup E: butyric acid for 4 days followed by 10 days in contact with PBS. The surface microhardness, elastic modulus, internal morphologic and chemical compositions of specimens were analyzed. RESULTS: The microhardness and elastic modulus values of all materials were significantly higher in the presence of PBS compared to exposure to butyric acid, with the same setting time (P < 0.01). After 4-day exposure to butyric acid followed by 10-day exposure to PBS, the microhardness values returned to the same level as 4-day exposure to PBS (P > 0.05). Biodentine showed significantly higher microhardness and elastic modulus values than other materials, while IRM displayed the lowest (P < 0.01). CONCLUSION: Biodentine seems the most suitable bioceramic cements when applied to an infected area with acidic pH. Further storage at neutral pH, e.g. PBS reverses the adverse effects on bioceramic cements caused by a low pH environment.
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Compostos de Cálcio , Óxidos , Humanos , Compostos de Alumínio/química , Ácido Butírico , Cálcio , Compostos de Cálcio/farmacologia , Compostos de Cálcio/química , Fosfatos de Cálcio , Cimentos Dentários/química , Combinação de Medicamentos , Teste de Materiais , Óxidos/química , Silicatos/farmacologia , Silicatos/químicaRESUMO
Streptococcus mutans (S. mutans) are cariogenic microorganisms. Sortase A (SrtA) is a transpeptidase that attaches Pac to the cell surface. The biofilm formation of S. mutans is promoted by SrtA regulated Pac. Myricetin (Myr) has a variety of pharmacological properties, including inhibiting SrtA activity of Staphylococcus aureus. The purpose of this research was to investigate the inhibitory effect of Myr on SrtA of S. mutans and its subsequent influence on the biofilm formation. Here, Myr was discovered as a potent inhibitor of S. mutans SrtA, with an IC50 of 48.66 ± 1.48 µM, which was lower than the minimum inhibitory concentration (MIC) of 512 ug/mL. Additionally, immunoblot and biofilm assays demonstrated that Myr at a sub-MIC level could reduce adhesion and biofilm formation of S. mutans. The reduction of biofilm was possibly caused by the decreased amount of Pac on the cells' surface by releasing Pac into the medium via inhibiting SrtA activity. Molecular dynamics simulations and mutagenesis assays suggested that Met123, Ile191, and Arg213 of SrtA were pivotal for the interaction of SrtA and Myr. Our findings indicate that Myr is a promising candidate for the control of dental caries by modulating Pac-involved adhesive mechanisms without developing drug resistance to S.mutans.
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Cárie Dentária , Streptococcus mutans , Biofilmes , Cárie Dentária/prevenção & controle , Flavonoides/farmacologia , HumanosRESUMO
Apical pressure during root canal irrigation is regarded as a key factor affecting the risk of irrigant extrusion. The aim of this study was to examine the effect of apical size on the apical pressure by positive and negative pressure syringe-needle and multisonic negative pressure irrigation. An extracted maxillary first molar with two separate buccal roots, one palatal root and four canals was selected. The roots of the molar were fixed in a specially made apparatus to acquire the apical pressure of the four root canals separately. The apical sizes tested were from sizes 10, 30, 40, 50, 60, 70, 80, 90, 110. Multisonic negative pressure irrigation protocol was as recommended by the manufacturer (45 mL/min), syringe-needle irrigation was done using 30-G side-vented needle 3 mm from the working length at 5 mL/min as a conventional positive pressure irrigation (SNI), and as negative pressure irrigation (NPSNI) using suction. Apical pressure by SNI was measured also at 10 mL/min with an open-ended 30G needle, for the smallest and largest apical sizes. Apical pressures by SNI stayed positive, except when suction was used (NPSNI). The apical pressure by multisonic negative pressure irrigation remained negative in all situations. With increasing apical size, apical pressure by SNI decreased, whereas with multisonic negative pressure irrigation and NPSNI, it was not affected by apical size. Large apical size did not result in higher apical pressure values compared to small apical sizes.
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Irrigantes do Canal Radicular , Irrigação Terapêutica , Cavidade Pulpar , Dente Molar , Preparo de Canal Radicular , Tratamento do Canal Radicular , Hipoclorito de Sódio , SeringasRESUMO
OBJECTIVES: Novel synthetic antimicrobial peptides which consist of a new immunomodulatory peptide 1018 and two different modifications with hydroxyapatite-binding affinity were developed. We compared the effect(s) of these peptides against oral plaque biofilms and measured their effectiveness in killing biofilm microbes and in reducing biofilm volume. MATERIALS AND METHODS: The high affinity hydroxyapatite (HA)-binding peptide 1018 (SHABP), the mild affinity HA-binding peptide 1018 (MHABP), and peptide 1018 without additional amino acid sequence (peptide 1018) were synthesized. Oral multispecies biofilms were grown anaerobically for 3 days. The biofilms were exposed to three peptides at two different concentrations (0.65 and 3.25 µmol/L) for 24, 48, and 72 h. The biofilms were also treated for 3 or 9 min with the peptides (3.25 µmol/L). The percentage of killed biofilm bacteria and biofilm volume were determined by using LIVE/DEAD viability staining and confocal laser scanning microscopy. RESULTS: SHABP was superior to MHABP and peptide 1018 in its killing efficacy of the pre-formed biofilms, especially at concentration of 3.25 µmol/L (p < 0.05). SHABP performed also better than MHABP and peptide 1018 in reducing the overall biofilm volume at both concentrations (p < 0.05). During the 3 days of long-term exposure, MHABP and peptide 1080 killed more bacteria in the top half of the biofilms, compared to bottom half. SHABP killed more bacteria in the bottom half (39%) of the biofilms than in the top half (29%) at day 1 (p < 0.05), whereas more bacteria were killed in the upper layers on days 2 and 3. SHABP killed a much higher percentage of plaque biofilm bacteria when used on 3-day-old biofilms for one or three times for 3 min than MHABP or peptide 1018 at high concentration (p < 0.05). CONCLUSIONS: The modified peptide 1018 with high HA-binding affinity had higher antimicrobial activity against biofilm microbes and reduced biofilm volume more than the other peptides tested. CLINICAL RELEVANCE: Modified peptide 1018 with high hydroxyapatite-binding affinity is a promising agent for use in oral antibiofilm strategies in the future.
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Anti-Infecciosos/farmacologia , Peptídeos Catiônicos Antimicrobianos/farmacologia , Bactérias/efeitos dos fármacos , Biofilmes/efeitos dos fármacos , Durapatita , Placa Dentária/microbiologia , Placa Dentária/prevenção & controle , Humanos , Testes de Sensibilidade MicrobianaRESUMO
BACKGROUND: To investigate the physical properties and the hydration behaviour of the fast-setting bioceramic iRoot FS Fast Set Root Repair Material (iRoot FS) and three other endodontic cements. METHODS: iRoot FS, Endosequence Root Repair Material Putty (ERRM Putty), gray and white mineral trioxide aggregate (G-MTA & W-MTA), and intermediate restorative material (IRM) were evaluated. The setting time was measured using ANSI/ADA standards. Microhardness was evaluated using the Vickers indentation test. Compressive strength and porosity were investigated at 7 and 28 days. Differential scanning calorimetry (DSC) was employed for the hydration test. RESULTS: iRoot FS had the shortest setting time of the four bioceramic cements (p < .001). The microhardness values of iRoot FS, ERRM Putty and MTA increased at different rates over the 28 days period. At day one, ERRM Putty had the lowest microhardness of the bioceramic cements (p < .001), but reached the same level as MTA at 4, 7 and 28 days. The microhardness of iRoot FS was lower than that of W-MTA at 7 and 28 days (p < .05). The porosity of the materials did not change after 7 days (p < .05). The compressive strength values at 28 days were significantly greater for all bioceramic groups compared to those at 7 days (p < .01). ERRM Putty had the highest compressive strength and the lowest porosity of the evaluated bioceramic cements (p < .05), followed by iRoot FS, W-MTA, and G-MTA, respectively. DSC showed that iRoot FS hydrated fastest, inducing an intense exothermic reaction. The ERRM Putty did not demonstrate a clear exothermic peak during the isothermal calorimetry test. CONCLUSIONS: iRoot FS had a faster setting time and hydrating process than the other bioceramic cements tested. The mechanical properties of iRoot FS, G-MTA and W-MTA were relatively similar.
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Cerâmica/química , Materiais Restauradores do Canal Radicular/química , Compostos de Alumínio/química , Materiais Biocompatíveis , Compostos de Cálcio/química , Força Compressiva , Combinação de Medicamentos , Óxidos/química , Silicatos/químicaRESUMO
Calcium hydroxide (CH) is applied to improve disinfection of root canals in most root canal retreatment. This study aimed to analyze the CH removal efficacy using 7 different root preparing files (K file, pre-curved K file, EndoActivator, Ultrasonic file, pre-curved ultrasonic file, F file and needle irrigation alone) with apical transportation. Standardized models of curved canal with such apical transportation or not were set up before applying CH to root canal for 7 days. Seven techniques described above were used for its removal. Then the roots were disassembled and digital photos were taken. The ratio of residual CH in the overall canal surface was calculated using the image analyzer image pro plus 6.0. The data were analyzed using one-way ANOVA with post hoc Tukey test. Results revealed that CH was effectively removed (P<0.05) by using all 6 mechanical methods except irrigation alone. In curved root canals with apical transportation, EndoActivator, pre-curved ultrasonic file and F file were found to be more effective in removing CH than the other four file (P<0.001), while there was no significant difference among EndoActivator, pre-curved ultrasonic file and F file groups (P>0.05). The percentage of residual CH in the canal with apical transportation was higher than that in the canal without apical transportation (P<0.05). In conclusion, CH can be hardly removed completely. Canal with apical transportation will result in insufficient CH removal. EndoActivator, pre-curved ultrasonic file and F file are more effective in the curved root canal with apical transportation.
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Cimentos Ósseos/farmacologia , Hidróxido de Cálcio/farmacologia , Cavidade Pulpar , Desinfetantes/farmacologia , Preparo de Canal Radicular/métodos , Animais , BovinosRESUMO
OBJECTIVE: To evaluate the bacteria debridement efficacy of two generations of sonic root canal irrigant activation systems: EndoActivator (Dentsply Sirona), the first generation, and SmartLite Pro EndoActivator, the second generation. METHODS: Instrumented, autoclaved, single-rooted human premolars were inoculated with Enterococcus faecalis (ATCC-29212) for 21 days. The bacteria biofilm-containing teeth were randomly divided into 5 groups (N=8): Group 1: Syringe-side-vented needle (S-N) delivery of saline for 1 min; Group 2: S-N delivery of 2% NaOCl for 1 min; Group 3: S-N delivery of 2% NaOCl for 5 min; Group 4: EndoActivator activation of 2% NaOCl for 1 min; Group 5: SmartLite Pro EndoActivator activation of 2% NaOCl for 1 min. The teeth were evaluated for bacterial reduction using CFU counts, and the percentages of dead bacteria within the dentinal tubules using confocal laser scanning microscopy. RESULTS: Activation of NaOCl with EndoActivator or SmartLite Pro EndoActivator significantly reduced the overall intracanal bacterial load, compared with S-N irrigant delivery (P<0.05), with no significant difference between the two agitation devices (P>0.05). Nevertheless, S-N delivery of 2% NaOCl for 5 min produced better bacteria debridement than either sonic agitation system. Different degrees of bacteria kill were identified in the coronal-middle portions and apical portion of the canal space. CONCLUSION: Delivery time of NaOCl affects the efficacy of bacteria disinfection. Activation for 1 min with the EndoActivator or SmartLite Pro EndoActivator demonstrated comparable canal wall biofilm and intracanal bacteria reduction efficacy when 2% NaOCl was used as irrigant for disinfecting E. faecalis in single-rooted teeth. CLINICAL SIGNIFICANCE: Although the sonic root canal irrigant activation devices investigated do not completely eliminate live bacteria biofilms from the canal space, they help reduce bacteria load during irrigant activation.
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Cavidade Pulpar , Irrigantes do Canal Radicular , Humanos , Cavidade Pulpar/microbiologia , Irrigantes do Canal Radicular/farmacologia , Irrigantes do Canal Radicular/uso terapêutico , Hipoclorito de Sódio/farmacologia , Hipoclorito de Sódio/uso terapêutico , Desbridamento , Enterococcus faecalis , Preparo de Canal RadicularRESUMO
HLA-DPB1*05:01:20 differs from HLA-DPB1*05:01:01:01 by one nucleotide in exon 3.
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Alelos , Povo Asiático , Sequência de Bases , Éxons , Cadeias beta de HLA-DP , Teste de Histocompatibilidade , Análise de Sequência de DNA , Humanos , Cadeias beta de HLA-DP/genética , Povo Asiático/genética , Análise de Sequência de DNA/métodos , Doadores de Tecidos , Alinhamento de Sequência , Códon , População do Leste AsiáticoRESUMO
This study aimed to create a caries classification scheme based on cone-beam computed tomography (CBCT) and develop two deep learning models to improve caries classification accuracy. A total of 2713 axial slices were obtained from CBCT images of 204 carious teeth. Both classification models were trained and tested using the same pretrained classification networks on the dataset, including ResNet50_vd, MobileNetV3_large_ssld, and ResNet50_vd_ssld. The first model was used directly to classify the original images (direct classification model). The second model incorporated a presegmentation step for interpretation (interpretable classification model). Performance evaluation metrics including accuracy, precision, recall, and F1 score were calculated. The Local Interpretable Model-agnostic Explanations (LIME) method was employed to elucidate the decision-making process of the two models. In addition, a minimum distance between caries and pulp was introduced for determining the treatment strategies for type II carious teeth. The direct model that utilized the ResNet50_vd_ssld network achieved top accuracy, precision, recall, and F1 score of 0.700, 0.786, 0.606, and 0.616, respectively. Conversely, the interpretable model consistently yielded metrics surpassing 0.917, irrespective of the network employed. The LIME algorithm confirmed the interpretability of the classification models by identifying key image features for caries classification. Evaluation of treatment strategies for type II carious teeth revealed a significant negative correlation (p < 0.01) with the minimum distance. These results demonstrated that the CBCT-based caries classification scheme and the two classification models appeared to be acceptable tools for the diagnosis and categorization of dental caries.
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OBJECTIVE: To investigate the value of magnetic resonance imaging (MRI) signal intensity ratios (SIRs) based on fat-suppressed T2-weighted imaging (FS-T2WI), together with demographic features, MRI anatomical characteristics, and SIRs of histopathological patterns of the tumors, in the differentiation of parotid pleomorphic adenoma (PA) from Warthin tumor (WT). STUDY DESIGN: In total, 90 patients with PA and 56 patients with WT were enrolled in the study. SIRs of tumor to normal parotid gland (SIR-T/P), spinal cord (SIR-T/S), and muscle (SIR-T/M) were calculated. Demographic and radiological features of the 2-patient groups were compared with univariate analysis and multivariate logistic regression analysis. The area under the receiver operating characteristic curve (AUC), sensitivity, and specificity were analyzed to evaluate the utility of SIRs in distinguishing between PA and WT. RESULTS: SIR-T/P exhibited outstanding discriminating ability (AUC = 0.934), SIR-T/S had excellent discrimination (AUC = 0.839), and SIR-T/M showed acceptable discrimination (AUC = 0.728). When SIR-T/P of 1.96 was selected as the cutoff value, sensitivity and specificity were 0.756 and 0.982, respectively. SIR-T/P, age, sex, and number of lesions were identified as independent predictors by multivariate logistic regression analysis. Differences in SIRs between histopathological patterns were significant. CONCLUSION: SIR-T/P based on FS-T2WI is an effective discriminator in the differential diagnosis between PA and WT. Age, sex, and number of lesions provided additional value in differentiation.
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Adenolinfoma , Adenoma Pleomorfo , Neoplasias das Glândulas Salivares , Humanos , Adenoma Pleomorfo/patologia , Adenolinfoma/diagnóstico por imagem , Adenolinfoma/patologia , Imageamento por Ressonância Magnética/métodos , Glândula Parótida/patologiaRESUMO
INTRODUCTION: Understanding the intricate anatomical morphology of fused-rooted mandibular second molars (MSMs) is essential for root canal treatment. The present study utilized a deep learning approach to identify the three-dimensional root canal morphology of MSMs from two-dimensional X-ray images. METHODS: A total of 271 fused-rooted MSMs were included in the study. Micro-computed tomography reconstruction images and two-dimensional X-ray projection images were obtained. The ground truth of three-dimensional root canal morphology was determined through micro-computed tomography images, which were classified into merging, symmetrical, and asymmetrical types. To amplify the X-ray image dataset, traditional augmentation techniques from the python package Augmentor and a multiangle projection method were employed. Identification of root canal morphology was conducted using the pretrained VGG19, ResNet18, ResNet50, and EfficientNet-b5 on X-ray images. The classification results from convolutional neural networks (CNNs) were then compared with those performed by endodontic residents. RESULTS: The multiangle projection augmentation method outperformed the traditional approach in all CNNs except for EfficientNet-b5. ResNet18 combined with the multiangle projection method outperformed all other combinations, with an overall accuracy of 79.25%. In specific classifications, accuracies of 81.13%, 86.79%, and 90.57% were achieved for merging, symmetrical, and asymmetrical types, respectively. Notably, CNNs surpassed endodontic residents in classification performance; the average accuracy for endodontic residents was only 60.38% (P < .05). CONCLUSIONS: CNNs were more effective than endodontic residents in identifying the three-dimensional root canal morphology of MSMs. The result indicates that CNNs possess the capacity to employ two-dimensional images effectively in aiding three-dimensional diagnoses.
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A novel calcium phosphate silicate bone cement (CPSC) was synthesized in a process, in which nanocomposite forms in situ between calcium silicate hydrate (C-S-H) gel and hydroxyapatite (HAP). The cement powder consists of tricalcium silicate (C(3)S) and calcium phosphate monobasic (CPM). During cement setting, C(3)S hydrates to produce C-S-H and calcium hydroxide (CH); CPM reacts with the CH to precipitate HAP in situ within C-S-H. This process, largely removing CH from the set cement, enhances its biocompatibility and bioactivity. The testing results of cell culture confirmed that the biocompatibility of CPSC was improved as compared to pure C(3)S. The results of XRD and SEM characterizations showed that CPSC paste induced formation of HAP layer after immersion in simulated body fluid for 7 days, suggesting that CPSC was bioactive in vitro. CPSC cement, which has good biocompatibility and low/no cytotoxicity, could be a promising candidate as biomedical cement.
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Cimentos Ósseos/química , Fosfatos de Cálcio/química , Silicatos/química , Cimentos Ósseos/farmacologia , Adesão Celular/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Células Cultivadas , Fibroblastos/citologia , Fibroblastos/efeitos dos fármacos , Fibroblastos/fisiologia , Gengiva/citologia , Gengiva/efeitos dos fármacos , Humanos , Concentração de Íons de Hidrogênio , Íons/química , Teste de Materiais , Concentração Osmolar , Propriedades de SuperfícieRESUMO
Calcium hydroxide (CH) dressing residues can compromise endodontic sealing. This study aimed to evaluate the amount of remaining CH in root canals after mechanical removal by four groups of irrigation techniques including needle irrigation only, ProTaper file, EndoActivator, and ultrasonic file. Fifteen extracted single-rooted teeth were collected and used for all four groups. The samples were firstly prepared by ProTaper rotary instruments, and then sectioned longitudinally through the long axis of the root canals, followed by final reassembling by wires. CH was kept in the canals for 7 days setting. The removal procedure began with 5 mL of 2.5% sodium hypochlorite (NaOCl) followed by 1 mL of 17% ethylenediaminetetraacetic acid and a final irrigation with 5 mL of 2.5% NaOCl solution for all groups. No additional agitation of the irrigant was performed in group 1, while agitation for 20 s between irrigants was done with F2 ProTaper rotary file in group 2, EndoActivator with tip size 25/.04 in group 3 and by an ultrasonic file 25/.02 in group 4. The total activation time was 60 s. The roots were then disassembled and captured by digital camera. The ratio of CH coated surface area to the surface area of the whole canal as well as each third of the canal was calculated. The data were statistically analyzed by one-way ANOVA using post hoc Tukey test. Results showed that none of the four techniques could remove all CH. No significant difference was found between EndoActivator and ultrasonic techniques. However, they both removed significantly more CH than ProTaper and needle irrigation (P=0.0001). In conclusion, the sonic and ultrasonic agitation techniques were more effective in removing intracanal medicaments than the ProTaper rotary file and needle irrigation in all thirds of the canal.
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Hidróxido de Cálcio/isolamento & purificação , Cavidade Pulpar/química , Irrigantes do Canal Radicular/isolamento & purificação , Preparo de Canal Radicular/instrumentação , Sonicação/instrumentação , Irrigação Terapêutica/instrumentação , Instrumentos Odontológicos , Desenho de Equipamento , Análise de Falha de Equipamento , Humanos , Técnicas In Vitro , Preparo de Canal Radicular/métodos , Sonicação/métodosRESUMO
OBJECTIVES: To examine the efficacy of glycine powder air-polishing on cleaning root canal sealer-smeared dentine. METHODS: Dentine surfaces were contaminated with a smear of epoxy resin-based sealer or tricalcium silicate-based sealer. The contaminated surfaces were cleaned with saline, 75% ethanol, or air-polishing with glycine powder. Uncontaminated dentine was used as the control. The cleanliness of pulpal floor dentine was examined using scanning electron microscopy and energy dispersive X-ray analysis. The effectiveness of the three cleaning protocols was examined by testing the tensile bond strength of a self-etching adhesive to the decontaminated dentine. Resin infiltration into the dentinal tubules was identified using confocal laser scanning microscopy (CLSM). RESULTS: Morphological examination and elemental analysis indicated that glycine powder air-polishing was more effective in removing the two sealers. Tensile bond strength of adhesive-bonded dentine was significantly reduced when either sealer was cleaned with saline or ethanol. Conversely, air-polishing restored the adhesive strength of the sealer-smeared dentine to the level of the control. Longer and denser resin tags were identified with CLSM when sealers were removed with air-polishing. CONCLUSIONS: Air-polishing with glycine powder was effective in cleaning sealer-smeared dentine, as demonstrated by the rejuvenation of the tensile bond strength of a self-etching adhesive to the decontaminated dentine. CLINICAL SIGNIFICANCE: Glycine powder air-polishing improves the cleanliness of root canal sealer-smeared dentine and rejuvenates adhesive bonding effectiveness.
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Colagem Dentária , Materiais Restauradores do Canal Radicular , Materiais Restauradores do Canal Radicular/química , Cavidade Pulpar , Pós , Resinas Epóxi/química , Etanol , Dentina , Teste de MateriaisRESUMO
OBJECTIVE: Oral lichen planus (OLP) is one of the most common oral mucosa diseases, and is mainly mediated by T lymphocytes. The metabolic reprogramming of activated T cells has been shown to transform from oxidative phosphorylation to aerobic glycolysis. The present study investigated the serum levels of glycolysis-related molecules (lactate dehydrogenase, LDH; pyruvic acid, PA; lactic acid, LAC) in OLP, and the correlation with OLP activity was assessed using the reticular, atrophic and erosive lesion (RAE) scoring system. METHODS: Univariate and multivariate linear regression functions based on scikit-learn were designed to predict the RAE scores in OLP patients, and the performance of these two machine learning functions was compared. RESULTS: The results revealed that the serum levels of PA and LAC were upregulated in erosive OLP (EOLP) patients, when compared to healthy volunteers. Furthermore, the LDH and LAC levels were significantly higher in the EOLP group than in the nonerosive OLP (NEOLP) group. All glycolysis-related molecules were positively correlated to the RAE scores. Among these, LAC had a strong correlation. The univariate function that involved the LAC level and the multivariate function that involved all glycolysis-related molecules presented comparable prediction accuracy and stability, but the latter was more time-consuming. CONCLUSION: It can be concluded that the serum LAC level can be a user-friendly biomarker to monitor the OLP activity, based on the univariate function developed in the present study. The intervention of the glycolytic pathway may provide a potential therapeutic strategy.
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Líquen Plano Bucal , Humanos , Líquen Plano Bucal/tratamento farmacológico , Líquen Plano Bucal/metabolismo , Líquen Plano Bucal/patologia , Linfócitos T/metabolismo , BiomarcadoresRESUMO
Nanomaterials (NMs) have increasingly been used for the diagnosis and treatment of head and neck cancers (HNCs) over the past decade. HNCs can easily infiltrate surrounding tissues and form distant metastases, meaning that most patients with HNC are diagnosed at an advanced stage and often have a poor prognosis. Since NMs can be used to deliver various agents, including imaging agents, drugs, genes, vaccines, radiosensitisers, and photosensitisers, they play a crucial role in the development of novel technologies for the diagnosis and treatment of HNCs. Indeed, NMs have been reported to enhance delivery efficiency and improve the prognosis of patients with HNC by allowing targeted delivery, controlled release, responses to stimuli, and the delivery of multiple agents. In this review, we consider recent advances in NMs that could be used to improve the diagnosis, treatment, and prognosis of patients with HNC and the potential for future research.
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With the purpose of investigating the bio-interaction between CNC and cells, the end-fluorescence CNC (FCNC) and surface-adsorbed glucosamine [(g)FCNC] were prepared by the region-selective modification and electrostatic adsorption strategy in this study. The cell growth was arrested in a time dependent manner when incubated with CNC in the low glucose environment. The small-size FCNC was preferred by the cells with the observation of higher affinity. Specifically, the affinity of (g)FCNC to the phagocytic cell RAW264.7 cell and kidney derived cell 293 t was generally increased in response to the "Warburg effect", which on the contrary was observed with the weak effect in the tumor cells. We confirmed the exocytosis of internalized rod-like nanocrystal was achieved by the packaging effect of exosomes. Our results revealed the underappreciated bio-interaction between CNC and different cells, which contributed the evidence of an inspiration for this natural nanomaterial in the cell-level application.