Exploring access cavity through non-carious cervical lesions: Impacts on instrumentation, obturation, and fracture resistance in mandibular incisors.

AIM: To compare the effects of Cervical Access Cavity (CervAC) and Traditional Access Cavity (TradAC) on root canal preparation, root canal filling, and fracture resistance in mandibular incisors. METHODOLOGY: Twenty recently extracted and intact mandibular incisors were initially scanned using a micro-CT device. The specimens were anatomically matched to create two groups (n = 10). A wedge-shaped non-carious cervical lesion (NCCL) was created on the buccal aspect of all teeth using a double-faced segmented diamond disc. In group 1, a TradAC was prepared, whilst in group 2, access was created through the simulated NCCL using a round diamond bur 1012. After root canal preparation with Rotate instruments sizes 15/0.04, 20/0.04, and 25/0.04, the teeth were scanned again and evaluated for root canal volume and surface area, static voxels, volume of removed dental tissue, and dentine thickness. After that, the root canals were filled using the single-cone technique, teeth were restored with composite resin, and subsequently rescanned to calculate the volume of filling materials and voids. Then, the restored teeth were subjected to fracture resistance tests using a universal testing machine. Statistical comparisons between groups were performed with the Mann-Whitney test or the Student's t-test, with a statistical significance level of 5%. RESULTS: Statistical comparisons indicated no significant differences between groups in terms of root canal volume, surface area, static voxels, removed root dentine, root canal filling volume, percentage of voids, or fracture resistance load (p > .05). Conversely, teeth prepared with TradAC showed a significantly higher percentage of dental tissue removed from the crown (p = .001) and a greater volume of filling material remnants in the pulp chamber (p < .001) compared to the CervAC group. A significantly lower percentage reduction in dentine thickness was observed only on the mesial aspect of root at Level 1 in TradAC group (p = .008). CONCLUSIONS: CervAC can be considered a viable alternative approach in the presence of NCCL in mandibular incisors.

Chronic alcohol and nicotine consumption as catalyst for systemic inflammatory storm and bone destruction in apical periodontitis.

AIM: To assess the periapical alveolar bone pattern and the serum levels of proinflammatory cytokines, biochemical markers and metabolites in rats subjected to chronic alcohol and nicotine consumption and induced apical periodontitis. METHODOLOGY: Twenty-eight male Wistar rats were divided into four groups: Control, Alcohol, Nicotine and Alcohol+Nicotine. The alcohol groups were exposed to self-administration of a 25% alcohol solution, while the other groups were given only filtered water. The nicotine groups received daily intraperitoneal injections of a nicotine solution (0.19 µL of nicotine/mL), whereas the other groups received saline solution. Periapical lesions were induced by exposing the pulps of the left mandibular first molars for 28 days. After euthanasia, the mandibles were removed and the percentage bone volume, bone mineral density, trabecular thickness, trabecular separation and trabecular number of the periapical bone were measured using micro-computed tomography images. Serum samples were collected for analysis of proinflammatory cytokines (IL-1ß, IL-4, IL-6 and TNF-α), biochemical and metabolomic analysis. Statistical analysis was performed with a significance level of 5%. Nonparametric data were analysed using the Kruskal-Wallis test followed by Dunn's test, while one-way anova followed by Tukey's test was performed for parametric data. RESULTS: The groups exposed to alcohol or nicotine consumption exhibited an altered bone pattern indicating lower bone density and higher levels of IL-1ß, IL-6 and TNF-α compared to the Control group (p < .05). Significant differences were observed among the groups in the levels of aspartate aminotransferase (AST), alanine aminotransferase (ALT), alkaline phosphatase, cholesterol, triglycerides, urea, creatinine, albumin, uric acid, bilirubin and calcium. Metabolomic analysis revealed significant differences in glycine, phosphocholine, lysine, lactate, valine, pyruvate and lipids (CH2 CH2 CO), n(CH2 ) and n(CH3 ). Most of these parameters were even more altered in the simultaneous consumption of both substances compared to single consumption. CONCLUSION: Alcohol and nicotine chronic consumption altered several metabolic markers, impaired liver and kidney function, increased the production of systemic proinflammatory mediators and harmed the periapical bone microarchitecture in the presence of apical periodontitis. The simultaneous consumption of alcohol and nicotine intensified these detrimental effects.

Apical periodontitis as an aggravating factor for the severity of rheumatoid arthritis: An animal study.

AIM: The present study investigated the influence of apical periodontitis (AP) on the severity of rheumatoid arthritis (RA) using a Wistar rat model. METHODOLOGY: Forty male Wistar rats were distributed across four groups (n = 10) based on the induction of RA and AP: Control, RA, AP, and RA + AP. RA was induced through two immunisations with type II collagen emulsified in incomplete Freund's adjuvant, followed by one immunisation with complete Freund's adjuvant. After 21 days of RA induction, AP was induced by exposing the pulp of four molars. Animals were euthanized after 28 days of pulp exposure. Through the experiment, visual and behavioural assessments tracked RA development and the knees and hind paw joints were measured. Micro-computed tomography scans of knees and hind paws, as well as mandibles and maxillae, were conducted to evaluate RA severity and the presence of AP, respectively. Serum samples were collected to analyse proinflammatory cytokines (IL-1ß, IL-2, IL-17, and TNF-α). Non-parametric data were analysed using the Kruskal-Wallis test followed by Student-Newman-Keuls test, while one-way anova followed by Tukey's test was performed for parametric data. A significance level of 5% was employed. RESULTS: All molars submitted to access cavity developed AP. All joints subjected to arthritis induction developed the disease, with AP + RA demonstrating a higher arthritis severity when compared to the RA group (p < .05). RA + AP group displayed a significantly larger hind paw and knee circumference compared to the RA group (p < .05). Micro-CT images of RA and RA + AP groups revealed joints with erosions and bone deformities, with a significantly lower bone surface density, lower trabecular number and higher trabecular separation in the hind paw and a significantly lower percent bone volume and higher trabecular separation in the knees of RA + AP group compared to RA group (p < .05). RA + AP group exhibited a significantly higher level of TNF-α and a lower level of IL-2 compared to all other groups (p < .05). Both RA and RA + AP groups had significantly higher IL-17 levels (p < .05), while there was no significant difference in IL-1ß levels among the groups (p > .05). CONCLUSION: The findings from this study underscore a possible relationship between apical periodontitis and the exacerbation of rheumatoid arthritis.

What makes an article a must read in medical education?

BACKGROUND: The dissemination of published scholarship is intended to bring new evidence and ideas to a wide audience. However, the increasing number of articles makes it challenging to determine where to focus one's attention. This study describes factors that may influence decisions to read and recommend a medical education article. METHODS: Authors analyzed data collected from March 2021 through September 2022 during a monthly process to identify "Must Read" articles in medical education. An international team of health sciences educators, learners, and researchers voted on titles and abstracts to advance articles to full text review. Full texts were rated using five criteria: relevance, methodology, readability, originality, and whether it addressed a critical issue in medical education. At an end-of-month meeting, 3-4 articles were chosen by consensus as "Must Read" articles. Analyses were used to explore the associations of article characteristics and ratings with Must Read selection. RESULTS: Over a period of 19 months, 7487 articles from 856 journals were screened, 207 (2.8%) full texts were evaluated, and 62 (0.8%) were chosen as Must Reads. During screening, 3976 articles (53.1%) received no votes. BMC Medical Education had the largest number of articles at screening (n = 1181, 15.8%). Academic Medicine had the largest number as Must Reads (n = 22, 35.5%). In logistic regressions adjusting for the effect of individual reviewers, all rating criteria were independently associated with selection as a Must Read (p < 0.05), with methodology (OR 1.44 (95%CI = 1.23-1.69) and relevance (OR 1.43 (95%CI = 1.20-1.70)) having the highest odds ratios. CONCLUSIONS: Over half of the published medical education articles did not appeal to a diverse group of potential readers; this represents a missed opportunity to make an impact and potentially wasted effort. Our findings suggest opportunities to enhance value in the production and dissemination of medical education scholarship.

Do the apical limit and diameter of the instrumentation influence the extrusion of sodium hypochlorite solution? A micro-CT study.

This study evaluated the influence of the apical limit and the diameter of the instrumentation on the extrusion of the irrigating solution. Sixty human lower premolars were distributed into 5 groups according to the apical limit and diameter of the root canal instrumentation (n = 12): (G-140) R40 instrument 1 mm above the tooth length (TL) (Control); (G-150) R50 instrument 1 mm above the TL; (GF25) R25 instrument at the TL; (GF40) R40 instrument at the root canal length and (GF50) R50 instrument at the TL. A space of 33.5 ± 1 mm3 was created for storage of the extruded solution. Omnipaque contrast was added to the NaOCl solution in a 1:2 ratio, totaling 15 mL of solution to allow its visualization when extruded in microcomputed tomography. Final irrigation was performed with a syringe and needle and activated with a passive ultrasonic irrigation (PUI). Three activation cycles were performed. Data were tabulated and statistically analyzed (one-way ANOVA) with a significance level set at 5%. It was observed irrigating solution extrusion after final irrigation in all groups. However, there were no statistically significant differences among experimental groups, regardless of the diameter or apical limit of root canal instrumentation (p > 0.05). The different apical limits and diameters of root canal instrumentation did not influence the volume of extruded irrigating solution using passive ultrasonic irrigation.

Are CAD-CAM milled glass fiber posts better than prefabricated or custom glass fiber posts for endodontically treated teeth? A systematic review with meta-analysis.

STATEMENT OF PROBLEM: Prefabricated and custom glass fiber posts have been successfully used to reconstruct endodontically treated teeth. However, the performance of computer-aided design and computer-aided manufacture (CAD-CAM) milled glass fiber posts is unclear. PURPOSE: The purpose of this systematic review with meta-analysis was to compare the fracture and bond strength and cement layer thickness of CAD-CAM milled glass fiber posts with prefabricated or custom glass fiber posts. MATERIAL AND METHODS: The protocol was registered in the Open Science Framework (http://osf.io/65jm7). Two reviewers searched the PubMed/MEDLINE, Web of Science, Embase, Scopus, and ProQuest databases for articles up to September 2023. In addition, the reference lists were hand searched. A meta-analysis was performed by using the RevMan 5.4 program. The risk of bias was assessed using the RoBDEMAT tool. RESULTS: After screening, a total of 18 studies were included. The CAD-CAM milled glass fiber posts showed higher fracture strength (P=.02; Standardized Mean Difference [SMD]: 0.57; 95% Confidence Interval [CI]: 0.07 to 1.07), bond strength (P=.010; SMD: 1.07; 95% CI: 0.26 to 1.89), and lower cement layer thickness (P=.009; SMD: -2.94; 95% CI: -5.15 to -0.73) when compared with prefabricated glass fiber posts. However, fracture strength (P=.53; SMD: 0.38; 95% CI: -0.79 to 1.54) and bond strength (P=.90; SMD: -0.05; 95% CI: -0.81 to 0.72) were statistically similar between CAD-CAM milled and custom glass fiber posts. Significant and substantial heterogeneity was observed in all meta-analyzes (P<.01; I>60%). The studies sufficiently reported most domains related to bias, except for randomization of samples, sample size rationale and reporting and operator blinding. CONCLUSIONS: CAD-CAM milled and custom glass fiber posts provide an effective and safe option for restoring endodontically treated teeth, especially for weakened teeth or enlarged root canals. However, further well-designed clinical research is recommended to strengthen these findings.

Effect of Processing Methods of Human Saliva on the Proteomic Profile and Protein-Mediated Biological Processes.

The use of saliva as a protein source prior to microbiological and biological assays requires previous processing. However, the effect of these processing methods on the proteomic profile of saliva has not been tested. Stimulated human saliva was collected from eight healthy volunteers. Non-processed saliva was compared with 0.22 µm filtered, 0.45 µm filtered, and pasteurized saliva, by liquid chromatography-mass spectrometry. Data are available via ProteomeXchange with identifier PXD039248. The effect of processed saliva on microbial adhesion was tested using bacterial and fungus species and in biological cell behavior using HaCaT immortalized human keratinocytes. Two hundred and seventy-eight proteins were identified in non-processed saliva, of which 54 proteins (≈19%) were exclusive. Saliva processing reduced identified proteins to 222 (≈80%) for the 0.22 µm group, 219 (≈79%) for the 0.45 µm group, and 201 (≈72%) for the pasteurized saliva, compared to non-processed saliva. The proteomic profile showed similar molecular functions and biological processes. The different saliva processing methods did not alter microbial adhesion (ANOVA, p > 0.05). Interestingly, pasteurized saliva reduced keratinocyte cell viability. Saliva processing methods tested reduced the proteomic profile diversity of saliva but maintained similar molecular functions and biological processes, not interfering with microbial adhesion and cell viability, except for pasteurization, which reduced cell viability.

PARP1- and CTCF-Mediated Interactions between Active and Repressed Chromatin at the Lamina Promote Oscillating Transcription.

Transcriptionally active and inactive chromatin domains tend to segregate into separate sub-nuclear compartments to maintain stable expression patterns. However, here we uncovered an inter-chromosomal network connecting active loci enriched in circadian genes to repressed lamina-associated domains (LADs). The interactome is regulated by PARP1 and its co-factor CTCF. They not only mediate chromatin fiber interactions but also promote the recruitment of circadian genes to the lamina. Synchronization of the circadian rhythm by serum shock induces oscillations in PARP1-CTCF interactions, which is accompanied by oscillating recruitment of circadian loci to the lamina, followed by the acquisition of repressive H3K9me2 marks and transcriptional attenuation. Furthermore, depletion of H3K9me2/3, inhibition of PARP activity by olaparib, or downregulation of PARP1 or CTCF expression counteracts both recruitment to the envelope and circadian transcription. PARP1- and CTCF-regulated contacts between circadian loci and the repressive chromatin environment at the lamina therefore mediate circadian transcriptional plasticity.

Multimethod analysis of three rotary instruments produced by electric discharge machining technology.

AIM: This study aimed to compare three rotary instruments produced by the EDM process with the heat-treated ProTaper Gold system regarding design, metallurgy, mechanical properties and shaping ability. METHODOLOGY: HyFlex EDM (25/~), Neoniti (25/.06), EDMax (25/.06) and ProTaper Gold (25/.08v) instruments (n = 58 per group) were compared regarding design, metallurgy and mechanical performance. Unprepared canal areas were calculated for each system after preparation of mesiobuccal, mesiolingual and distal canals of mandibular molars (15 canals per group) using micro-CT technology. Statistical analyses were performed using One-way anova post-hoc Tukey and Kruskal-Wallis post-hoc Dunn's tests (α = 5%). RESULTS: All instruments had asymmetrical blades, no radial lands, no major defects and almost equiatomic nickel/titanium ratios, but different cross-section designs, tip geometries and surface appearances. Although instruments had distinct transformation temperature curves, they showed crystallographic martensitic arrangement at 21°C and mixed austenite plus R-phase at body temperature. Neoniti and HyFlex EDM showed similar results in all mechanical tests (p > .05), while EDMax and ProTaper Gold had similar time to fracture (p = .841), maximum bending load (p = .729), and cutting ability (p = .985). ProTaper Gold showed the highest torque to failure (p < .001) and HyFlex EDM had the lowest buckling resistance (p < .001). Mean percentages of unprepared canal areas ranged from 20.4% to 25.7% in the mesial canals, and from 20.8% to 26.2% in the distal canal, with no statistical differences among systems (p > .05). CONCLUSIONS: Instruments' geometry and phase transformation temperatures influenced the results of the mechanical tests, but not their shaping ability.

Volumetric changes in root canal sealers in ex vivo and a novel animal model approach.

AIM: This study aimed to evaluate the volumetric change of root canal sealers through micro-computed tomographic analysis using a novel in vivo model and to compare the results with those obtained using an ex vivo test. METHODOLOGY: Eighteen single-rooted teeth were cut to 5 mm length from the root apex. The root canals were uniformly enlarged and filled with EndoSequence BC Sealer or AH Plus Jet root canal sealers. Samples were stored at 37°C and 95% relative humidity for 24 h and then scanned with a micro-CT device. Twelve samples (n = 6 for each sealer) were implanted in the subcutaneous tissue of Wistar rats, while six samples (n = 3 for each sealer) were immersed in 20 mL of phosphate-buffered saline (PBS) at 37°C at neutral pH. After 7 and 30 days, teeth were removed from subcutaneous tissue or PBS and rescanned. Statistical analysis of volume changes was performed using Shapiro-Wilk's test and independent t-test (p < .05). RESULTS: AH Plus Jet had smaller volume changes (-2.2 to +0.77%) than EndoSequence BC Sealer (-2.0 to +4.0%) (p < .05), in the two tested models. The volume of the root canal sealers decreased over time (p < .05), in vivo. AH Plus Jet results varied between the in vivo and ex vivo results (p < .05), while EndoSequence BC Sealer presented similar volume losses for both experimental models (p > .05). CONCLUSION: EndoSequence BC Sealer lost more volume than AH Plus Jet. The experimental conditions influenced the volumetric change of AH Plus Jet but not the EndoSequence BC Sealer. The ex vivo model should be further explored as a methodological alternative to assess the volumetric changes of root canal sealers without causing harm to animals.

Marginal gaps and voids using two warm compaction techniques and different sealers: a micro-CT study.

OBJECTIVE: To assess the percentage of marginal gaps and voids in oval-shaped canals obturated by using two warm compaction techniques with a Bio-C sealer and AH Plus Jet. MATERIALS AND METHODS: Forty canines with oval canals were scanned by microcomputed tomography (micro-CT), and root canal preparation was performed with an XP-endo Shaper system and irrigated with 5.25% sodium hypochlorite. Then, the specimens were paired into four groups (n=10) according to the root canal filling technique and endodontic sealer: Bio-C sealer and continuous wave of condensation, Bio-C sealer and Tagger's hybrid, AH Plus Jet and continuous wave of condensation, and AH Plus Jet and Tagger's hybrid. After root canal filling, a new scan was performed. The percentage of marginal gaps and voids was calculated with the ImageJ software, and the data were analyzed statistically using two-way ANOVA and Tukey tests, with a significance level of 5%. RESULTS: The percentage of marginal gaps was significantly lower in the Bio-C sealer than in AH Plus Jet (p=0.021) regardless of the technique. However, no difference was found in the percentage of voids between root canal filling techniques and the endodontic sealer (p>0.05). CONCLUSION: Both sealers and techniques demonstrated good quality of root canal filling. However, the use of the Bio-C sealer enhanced the filling ability by reducing marginal gaps, regardless of the root canal filling technique. CLINICAL RELEVANCE: This study highlights the better performance of the Bio-C sealer in the quality of the root canal filling, reducing marginal gaps when compared to AH Plus Jet independent of the technique.

Unraveling the signs and symptoms of oral conditions that affect daily life activities and oral health-related quality of life.

OBJECTIVES: Since oral conditions negatively affect oral health-related quality of life (OHRQoL), this study evaluated which oral clinical condition, signs, and symptoms are associated with the impact on OHRQoL, its domains, and specific daily life activities among adults. MATERIALS AND METHODS: Data from a probabilistic sample of adults (35-44 years old) was used. The Oral Impacts on Daily Performance (OIDP) was used to evaluate OHRQoL, its domains (physical, psychological, and social), and nine daily life activities. Signs and symptoms of oral diseases (dental caries, periodontal disease, need for dental prothesis, and tooth loss) and oral self-perception were considered. Descriptive, bivariate, and multi-level analyses were conducted. RESULTS: A total of 5,834 adults were included, of which 52.9% had some negative impact of oral conditions on OHRQoL. Difficulty in eating was the most affected daily life activity. For multiple models, dental caries lesions (cavities), filled teeth with caries, gingival bleeding, periodontal pocket, dental pain, need for upper or lower dental prosthesis, and oral health self-perception were associated (p < 0.05) with overall OHRQoL or at least one of its domains. The impact on daily life activities of each individual was associated with at least one oral condition. Dental caries lesions (cavity) and dental pain were associated (p < 0.05) with the impact on most daily life activities evaluated. CONCLUSIONS: Different signs and symptoms of prevalent oral diseases are associated with the impact on specific daily life activities among adults, which may compromise the OHRQoL. CLINICAL RELEVANCE: Knowledge of how signs, symptoms, and oral conditions affect OHRQoL and daily life activities can provide essential information for clinicians to establish proper disease management and preventive strategies focusing on improving patients' lives.

Analysis of Different Tidal Volumes on Ventilatory Mechanics and Arterial Blood Gas Variables in Patients Undergoing Cardiac Surgery.

Introduction: Cardiovascular diseases have been increasing gradually each year, and their incidence has reached 80%. Mechanical ventilation (MV) is essential in the postoperative period of cardiac surgery (CS) due to anesthetic induction. The tidal volume (TV) is a parameter that depends on the conditions of the respiratory system mechanics, aiming at the reduction of dynamic hyperinflation. Objective: Analyze the effect of different TVs on blood gas analysis variables and respiratory mechanics in patients submitted to CS. Materials and methods: This was an uncontrolled randomized clinical trial. Patients were randomized by lottery into the following two groups: One group was ventilated with a TV of 6 mL/kg; while the other received a TV of 8 mL/kg. After 30 minutes of admission with the VT, blood gas analysis data were evaluated, such as pH, oxygen arterial pressure (PaO2), arterial pressure of carbon dioxide (PaCO2), and peripheral oxygen saturation (SpO2). The evaluation of respiratory mechanics was composed of static and dynamic compliance, airway resistance, and driving pressure. Results: A total of 78 patients were included, 58% of whom were males with a mean age of 55 ± 13 years. It was observed that there were no significant differences regarding respiratory mechanics, only the driving pressure presented statistical significance, the group 6 mL/kg was 8.3 ± 2.5 in the group 8 mL/kg 10.4 ± 2.1 presenting a value of (p < 0.001). Conclusion: Based on the findings of the present study, we conclude that different TVs do not significantly alter the blood gas variables and do not influence the respiratory mechanics of patients undergoing CS. How to cite this article: Cordeiro A, Souza A, de Brito Lima CR, Araújo J, Mascarenhas H, Guimarães A. Analysis of Different Tidal Volumes on Ventilatory Mechanics and Arterial Blood Gas Variables in Patients Undergoing Cardiac Surgery. Indian J Crit Care Med 2023;27(12):930-933.

Synthesis, biological evaluation and molecular modeling studies of novel 1,2,3-triazole-linked menadione-furan derivatives as P2X7 inhibitors.

The P2X7 receptor (P2X7R) is an ion channel that promotes the passage of ions through the membrane through brief stimulation once activated by ATP, its endogenous opener. However, prolonged stimulation with ATP, which occurs in pathological processes, opens a nonselective pore in the plasma membrane, allowing the passage of large molecules and leading to cytokine release or even cell death. In this sense, the search for new inhibitors for this receptor has attracted a great deal of attention in recent years. Considering the booming of biomass upgrading reactions in recent years and the continued efforts to synthesize biologically active molecules containing the 1,2,3-triazole ring, in the present work, we aimed to investigate whether triazole-linked menadione-furan derivatives could present P2X7R inhibitory activity. The novel compounds were tested for their inhibitory activity on ATP-induced dye uptake in peritoneal macrophages. Some have shown promising results, having displayed IC50 values lower than that of the P2X7R inhibitor BBG. Molecular docking studies also indicated that the active compounds bind to an allosteric site on P2X7R, presenting potential P2X7R inhibition.

Selection of plasma donors for the production of anti-SARS-CoV-2 immunoglobulin-based therapies: Strategies for quantitative antibody measurements.

Even after two years of the pandemic, a completely effective treatment against SARS-CoV-2 has not yet been established. Considering this fact and the emergence of successive new viral variants, the development of therapies based on natural polyclonal antibodies recovered from convalescent plasma remains relevant. This study presents a comparison between different methods of screening antibodies in samples of 41 individuals previously diagnosed with COVID-19. We found a significant correlation between Abbot Architect anti-SARS-CoV-2 IgG and Abbott Allinity SARS-CoV-2 IgG II Quantitative assay intensity of reactivity and neutralizing antibody (nAb) titers. Thus, we propose an initial antibody screening with IgG anti-N Abbott Architect test, with an index of, for example, > 3.25 or SARS-CoV-2 IgG II Quantitative Abbott Allinity assay > 137.65 AU/mL as good predictors of Nab ≥ 1:80. For the quantitative method, this threshold demonstrated a 100 % sensitivity and 80 % specificity, with 97.3 % accuracy. An interesting observation was the increase in the neutralizing activity of the anti-SARS-CoV-2 antibodies with the longest interval between the end of the symptoms and the collection, demonstrating that the delay in plasma collection does not affect the achievement of adequate nAbs levels. These results demonstrate the possibility of using faster and more widely available commercial serological tests with a good correlation with viral neutralization tests in culture, allowing for optimized large-scale donor selection, which will be of utmost importance for the development of therapies such as hyperimmune immunoglobulin.

Influence of access cavity preparation on the dentine thickness of mesial canals of mandibular molars prepared with reciprocating instruments.

AIM: To evaluate the influence of traditional and conservative access cavity preparations on the remaining dentine thickness in the coronal third of mesial canals of extracted mandibular molars prepared with reciprocating instruments using micro-computed tomography as the analytical tool. METHODOLOGY: Seventy extracted mandibular molars were scanned at a pixel size of 19 µm. From this initial sample, 20 teeth were selected, pair-matched and distributed into two groups (n = 10) according to the access cavity preparation: traditional (TradAC) or conservative (ConsAC). The root canals were sequentially enlarged with Reciproc Blue R25 (size 25, 0.08v taper) and R40 (size 40, 0.06v taper) instruments. A new scan was performed and the postoperative stacks were coregistered with their respective preoperative datasets. A colour-coded cross sections of the roots were created and used to identify and measure the smallest dentine thickness related to both MB and ML canals at 1.0-mm intervals from the furcation level of up to 5 mm in the apical direction, in both mesial and distal aspects of the roots, before and after preparation. The statistical analyses were performed with paired-samples t-test, independent-samples Student T-test and Chi-Square test with a significance level of 5%. RESULTS: At all levels of both groups, dentine thickness before preparation was greater than after preparation (p < .05). No difference in the percentage of dentine reduction was observed between TradAC and ConsAC groups (p > .05), but a significantly greater reduction was observed to the distal aspect of the roots (p < .05). After root canal preparation, dentine thinner than 0.5 mm was observed mostly along the distal aspect of the root (10% to 15%) of the MB and ML canals, with no influence of the access cavity type on its incidence to either mesial (X2  = 1.66; p = .2) or distal (X2  = 0.40; p = .5) directions. In the TradAC group, dentine thickness in most slices was greater than 1.0 mm after preparation (n = 124) whilst, in the ConsAC, it ranged from 0.5 to 1.0 mm (n = 136). CONCLUSION: Traditional or conservative access cavity preparation in extracted mandibular molars did not influence the remaining dentine thickness in the coronal third of mesial canals enlarged with thermomechanically treated nickel-titanium reciprocating instruments.

Natural and artificial pollination of white-fleshed pitaya.

To produce pitaya (Hylocereus spp.), it is essential that pollination occur, either artificially or by pollinating agents. This study evaluated the viability of self-pollination, cross-pollination, and natural pollination, as well as pollen viability, stigma receptivity and ideal pollination window in pitaya flowers (Hylocereus spp.). An experiment was conducted with a randomized block design consisting of four treatments: T1: manual self-pollination; T2: nocturnal open pollination; T3: diurnal open pollination; and T4: manual cross-pollination - red-fleshed pitaya [ Hylocereus polyrhizus] pollen placed on white-fleshed pitaya [ Hylocereus undatus] stigma. The experiment had four replicates, with two plants per replicate (two flowers per plant), totaling 16 flowers per treatment. The analyzed variables were fruit weight, length, diameter, titratable acidity, pH, soluble solids, and SS/TA ratio; the germination percentage of pollen grains; and the receptivity of stigmas. Artificial pollination (self- and cross-pollination) of white-fleshed pitaya (Hylocereus undatus) is viable, resulting in larger fruits than natural pollination, with cross-pollination being the most recommended. Throughout the floral opening period, the pitaya flower (Hylocereus spp.) has receptive stigma capable of receiving pollen. The flowers exhibit the highest pollen germination rate at 7 p.m, which is the ideal pollination window for pitaya.

Photodynamic therapy for root canal disinfection in endodontics: an umbrella review.

To evaluate and synthesize the evidence from the individual reviews that evaluated the efficacy of PDT therapy in root canal disinfection by undertaking an umbrella review. The protocol of the review was registered in the PROSPERO database under number CRD42021214056. The literature search was conducted using the following electronic databases: PubMed, Scopus, Web of Science, BVS, Cochrane Database of Systematic Reviews, Embase, and Epistemonikos, from inception to July 2021. Systematic reviews that evaluated the efficacy of PDT for root canal disinfection were included. Two authors independently performed a literature search, data extraction, and quality assessment of the included studies. Any disagreements were resolved by a third reviewer. The quality of the reviews was assessed using the AMSTAR 2 tool and the final categorization of each systematic reviews was classified as of "high," "moderate," "low," or "critically low" quality. Six systematic reviews were included in the current umbrella review and all of them were graded as critically low quality. From the critically low-quality evidence available, this umbrella review showed that the efficacy of PDT in root canal disinfection remains yet undetermined.

Structural and functional analysis of broad pH and thermal stable protease from Penicillium aurantiogriseum URM 4622.

This study aimed to better characterize a recently purified stable extracellular alkaline peptidase produced by Penicillium aurantiogriseum (URM 4622) through fluorescence spectroscopy, far-UV circular dichroism, kinetic and thermodynamic models to understand its' structure-activity and denaturation. Fluorescence data showed that changing pH leads to tryptophan residues exposure to more hydrophilic environments at optimum activity pH 9.0 and 10.0. When thermally treated, it displayed less unfolding at these pH values, along with 4-fold less photoproducts formation than at neutral pH. Different pH CD spectra showed more ß-sheet (21.5-43.0%) than α-helix (1-6.2%). At pH9.0, more than 2-fold higher α-helix content than any other pH. The melting temperature (Tm) was observed between 50 and 60 °C at all pH studied, with lower Tm at pH 9.0-11.0 (54.9-50.3 °C). The protease displayed two phase transition, with two energies of denaturation, and a 4-fold higher thermal stability (ΔH°m) than reports for other microorganism's proteases. An irreversible folding transition occurs between 50 and 60 °C. It displayed energies of denaturation suggesting higher thermal stability than reported for other microorganism's proteases. These results help elucidating the applicability of this new stable protease.

Bioactive 1,2,3-Triazoles: An Account on their Synthesis, Structural Diversity and Biological Applications.

The triazole heterocycle is a privileged scaffold in medicinal chemistry, since its structure is present in a large number of biologically active molecules, including several drugs currently in the market. Due to their vast applications, a wide variety of methods are described for their preparation, such as the 1,3-dipolar cycloaddition and processes involving diazo compounds and diazo transfer reactions. Considering the significant number of contributions from our research group to this chemistry in recent decades, in this account we discuss both the development of new methods for the synthesis of 1,2,3-triazoles and the preparation of new triazole-functionalized biologically active molecules using classical approaches.