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Australian Endodontic Journal : the... Sep 2023This study investigated variation in working length during multiple-visit endodontic treatment. Patients (N = 106) with pulpitis or pulp necrosis, with or without... (Observational Study)
Observational Study
This study investigated variation in working length during multiple-visit endodontic treatment. Patients (N = 106) with pulpitis or pulp necrosis, with or without apical periodontitis, were included. During the first appointment, glide path was performed with ProGlider and shaping with ProTaper Next. Working length was detected four times. Working length was then re-recorded prior to filling during the second appointment and a 0.5 mm threshold was selected as the minimum clinically meaningful variation. A logistic regression model was used to evaluate the impact of tooth anatomy, preoperative pulp status, apical periodontitis and lesions of endodontic origin on working length variation. Working length varied between first and second appointments in 34% of patients. The presence of apical periodontitis was the only variable significantly associated with variation in working length (p = 0.011). These data suggest that working length should be re-checked prior to root canal filling to prevent procedural errors.
Topics: Humans; Root Canal Preparation; Dental Pulp Cavity; Tooth Apex; Pulpitis; Periapical Periodontitis
PubMed: 36281895
DOI: 10.1111/aej.12703 -
Journal of Conservative Dentistry and... 2023This study evaluated the prevalence, configurations, and correlation of isthmuses at coronal, middle, and apical root 3 in mandibular molars of the Indian population...
OBJECTIVES
This study evaluated the prevalence, configurations, and correlation of isthmuses at coronal, middle, and apical root 3 in mandibular molars of the Indian population using micro-computed tomography μCT).
MATERIALS AND METHODS
One hundred and five permanent mandibular molar teeth were scanned under μCT. The axial sections were analyzed at the coronal, middle, and apical thirds of the root for isthmus types and classified according to Hsu and Kim's classification. Descriptive statistics for each isthmus type were calculated. The correlations between the apical, middle, and coronal thirds of the root were determined using Pearson's correlation coefficient.
RESULTS
Type IV isthmus was the most common in the coronal third of the mesial root of mandibular 1 molar (42.9%), while Type V was prevalent in the coronal third of the mesial root of 2 molar (42.9%). Type I isthmus was found to be highly prevalent in the middle 3 (71.4%) and apical 3 (61.9%) of mesial roots of 1 molars, and in the middle 3 (71.4%) and apical 3 (42.9%) of mesial roots of 2 molars. Type V isthmus was the most prevalent in all the thirds of the distal roots of both 1 and 2 molars, ranging from 40% to 50%. Furthermore, a strong correlation of 0.965 ( < 0.01) was found between the isthmuses in the apical and middle thirds of roots.
CONCLUSION
There are variations in the prevalence and type of isthmuses across different sections of the root, including the presence of atypical isthmuses. Micro-CT with high-resolution imaging and three-dimensional reconstruction is crucial for investigating root canal morphology. Clinicians could benefit from considering demographic characteristics to better predict the presence of isthmus variations.
CLINICAL RELEVANCE
The isthmus configurations and frequency differ at each section of mandibular teeth.
PubMed: 38292355
DOI: 10.4103/JCDE.JCDE_52_23 -
American Journal of Physiology. Lung... Aug 2023Bronchoconstriction is the main physiological event in asthma, which leads to worsened clinical symptoms and generates mechanical stress within the airways. Virus...
Bronchoconstriction is the main physiological event in asthma, which leads to worsened clinical symptoms and generates mechanical stress within the airways. Virus infection is the primary cause of exacerbations in people with asthma, however, the impact that bronchoconstriction itself on host antiviral responses and viral replication is currently not well understood. Here we demonstrate how mechanical forces generated during bronchoconstriction may suppress antiviral responses at the airway epithelium without any difference in viral replication. Primary bronchial epithelial cells from donors with asthma were differentiated at the air-liquid interface. Differentiated cells were apically compressed (30 cmHO) for 10 min every hour for 4 days to mimic bronchoconstriction. Two asthma disease models were developed with the application of compression, either before ("poor asthma control model," = 7) or following ("exacerbation model," = 4) rhinovirus (RV) infection. Samples were collected at 0, 24, 48, 72, and 96 h postinfection (hpi). Viral RNA, interferon (IFN)-β, IFN-λ, and host defense antiviral peptide gene expressions were measured along with IFN-β, IFN-λ, TGF-β, interleukin-6 (IL-6), and IL-8 protein expression. Apical compression significantly suppressed RV-induced IFN-β protein from 48 hpi and IFN-λ from 72 hpi in the poor asthma control model. There was a nonsignificant reduction of both IFN-β and IFN-λ proteins from 48 hpi in the exacerbation model. Despite reductions in antiviral proteins, there was no significant change in viral replication in either model. Compressive stress mimicking bronchoconstriction inhibits antiviral innate immune responses from asthmatic airway epithelial cells when applied before RV infection. Bronchoconstriction is the main physiological event in asthma, which leads to worsened clinical symptoms and generates mechanical stress within the airways. Virus infection is the primary cause of exacerbations in people with asthma, however, the impact of bronchoconstriction on host antiviral responses and viral replication is unknown. We developed two disease models, in vitro, and found suppressed IFN response from cells following the application of compression and RV-A1 infection. This explains why people with asthma have deficient IFN response.
Topics: Humans; Rhinovirus; Immunity, Innate; Asthma; Antiviral Agents; Epithelial Cells; Picornaviridae Infections
PubMed: 37280545
DOI: 10.1152/ajplung.00074.2022 -
Cellular & Molecular Biology Letters Aug 2023Chronic apical periodontitis is a prevalent oral disease characterized by bone loss, and its underlying mechanisms remain unclear. This study aimed to investigate the...
Chronic apical periodontitis is a prevalent oral disease characterized by bone loss, and its underlying mechanisms remain unclear. This study aimed to investigate the role and mechanism of the serine protease GZMA in osteoclasts during chronic apical periodontitis. To address this, we employed crRNA/Cas13d to inhibit GZMA expression and examined its impact on osteoclast behavior. Our findings revealed that GZMA plays a significant role in promoting osteoclast cell proliferation while inhibiting cell apoptosis. Additionally, the inhibition of GZMA led to a notable increase in miR-25-3p expression, which, in turn, downregulated the expression of TGF-β. Consequently, the reduction in TGF-β expression led to a decrease in PAR1 expression within the PARs pathway. These results suggest that GZMA might serve as a promising therapeutic target for the treatment of chronic apical periodontitis. Furthermore, our study highlights the potential of targeting GZMA using crRNA/Cas13d as a valuable approach for future therapeutic interventions.
Topics: Humans; Clustered Regularly Interspaced Short Palindromic Repeats; Osteoclasts; Apoptosis; RNA, Guide, CRISPR-Cas Systems; Transforming Growth Factor beta; Periapical Periodontitis; Granzymes
PubMed: 37626297
DOI: 10.1186/s11658-023-00477-2 -
Cureus Nov 2023The main goal of root canal treatment is to eliminate the infection in the complex root canal system for the long-term preservation of a functional tooth. Proper... (Review)
Review
The main goal of root canal treatment is to eliminate the infection in the complex root canal system for the long-term preservation of a functional tooth. Proper debridement of the root canal system, especially in the apical portion, is essential for successful root canal treatment. The complexity of the canal anatomy in the apical region plays a crucial role in reducing the microbial load. Therefore, clinicians must have a thorough knowledge of the anatomy of the root canal system and its variations, especially in the apical portion. Root canal configurations in cross-section have been classified as round, oval, long oval, flattened, or irregularly shaped. Treating oval, long oval, flattened, or irregularly shaped canals is challenging and should be approached differently than a circular canal. Recognizing the root canal shape and apical anatomy determines the different strategies to be used in cleaning, shaping, and obturation to achieve the best result of root canal treatment. The recent development of the instrumentation system improves the treatment outcome for clinicians and patients. This review aimed to discuss the definition, prevalence, and instrumentation for cleaning and shaping in the apical area with the complexity of root canal systems. Therefore, with the aid of this review, we can better understand the variations in the anatomy of the root canal, especially at the apical portion.
PubMed: 38111413
DOI: 10.7759/cureus.49024 -
Cells & Development Mar 2024The basement membrane (BM) demarcating epithelial tissues undergoes rapid expansion to accommodate tissue growth and morphogenesis during embryonic development. To...
The basement membrane (BM) demarcating epithelial tissues undergoes rapid expansion to accommodate tissue growth and morphogenesis during embryonic development. To facilitate the secretion of bulky BM proteins, their mRNAs are polarized basally in the follicle epithelial cells of the Drosophila egg chamber to position their sites of production close to their deposition. In contrast, we observed the apical rather than basal polarization of all major BM mRNAs in the outer epithelial cells adjacent to the BM of mouse embryonic salivary glands using single-molecule RNA fluorescence in situ hybridization (smFISH). Moreover, electron microscopy and immunofluorescence revealed apical polarization of both the endoplasmic reticulum (ER) and Golgi apparatus, indicating that the site of BM component production was opposite to the site of deposition. At the apical side, BM mRNAs colocalized with ER, suggesting they may be co-translationally tethered. After microtubule inhibition, the BM mRNAs and ER became uniformly distributed rather than apically polarized, but they remained unchanged after inhibiting myosin II, ROCK, or F-actin, or after enzymatic disruption of the BM. Because Rab6 is generally required for Golgi-to-plasma membrane trafficking of BM components, we used lentivirus to express an mScarlet-tagged Rab6a in salivary gland epithelial cultures to visualize vesicle trafficking dynamics. We observed extensive bidirectional vesicle movements between Golgi at the apical side and the basal plasma membrane adjacent to the BM. Moreover, we showed that these vesicle movements depend on the microtubule motor kinesin-1 because very few vesicles remained motile after treatment with kinesore to compete for cargo-binding sites on kinesin-1. Overall, our work highlights the diverse strategies that different organisms use to secrete bulky matrix proteins: while Drosophila follicle epithelial cells strategically place their sites of BM protein production close to their deposition, mouse embryonic epithelial cells place their sites of production at the opposite end. Instead of spatial proximity, they use the microtubule cytoskeleton to mediate this organization as well as for the apical-to-basal transport of BM proteins.
Topics: Animals; Mice; Basement Membrane; Kinesins; RNA, Messenger; In Situ Hybridization, Fluorescence; Microtubules; Epithelial Cells; Drosophila; Endoplasmic Reticulum
PubMed: 38103869
DOI: 10.1016/j.cdev.2023.203898 -
Journal of Experimental Botany Aug 2023The process of apical dominance by which the apical bud/shoot tip of the plant inhibits the outgrowth of axillary buds located below has been studied for more than a...
The process of apical dominance by which the apical bud/shoot tip of the plant inhibits the outgrowth of axillary buds located below has been studied for more than a century. Different approaches were used over time, with first the physiology era, the genetic era, and then the multidisciplinary era. During the physiology era, auxin was thought of as the master regulator of apical dominance acting indirectly to inhibit bud outgrowth via unknown secondary messenger(s). Potential candidates were cytokinin (CK) and abscisic acid (ABA). The genetic era with the screening of shoot branching mutants in different species revealed the existence of a novel carotenoid-derived branching inhibitor and led to the significant discovery of strigolactones (SLs) as a novel class of plant hormones. The re-discovery of the major role of sugars in apical dominance emerged from modern physiology experiments and involves ongoing work with genetic material affected in sugar signalling. As crops and natural selection rely on the emergent properties of networks such as this branching network, future work should explore the whole network, the details of which are critical but not individually sufficient to solve the 'wicked problems' of sustainable food supply and climate change.
Topics: Plant Shoots; Plant Growth Regulators; Cytokinins; Indoleacetic Acids; Abscisic Acid; Sugars; Gene Expression Regulation, Plant
PubMed: 37076257
DOI: 10.1093/jxb/erad137 -
International Endodontic Journal Nov 2023The aim of this study is to compare the stress produced on the internal walls of simulated canals by nine rotary and four reciprocating systems.
AIM
The aim of this study is to compare the stress produced on the internal walls of simulated canals by nine rotary and four reciprocating systems.
METHODOLOGY
Sixty-five isotropic transparent blocks containing a 60° curved and tapered simulated canal were selected and distributed into 13 groups (n = 5) according to the preparation system: BioRace, HyFlex EDM, iRaCe, Mtwo, One RECI, ProTaper Next, RaCe EVO, Reciproc, Reciproc Blue, R-Motion, VDW.ROTATE, XP-Endo Rise Shaper, and XP-Endo Shaper. Each resin block was mounted in a vice and a digital camera recorded the entire sequence of each preparation system through a circular polariscope set for dark field analysis. The video frames when each instrument reached the end of the coronal, middle, and apical thirds of the canal were extracted from the recordings and analysed by two independent observers regarding the stress generated on the canal walls using a semi-quantitative evaluation on a 0-5 scale. Intra- and inter-observer agreement were subjected to the Cohen's Kappa coefficient test, whilst the experimental results were compared using Kruskal-Wallis test post hoc pairwise comparisons with Bonferroni correction (α = 5%).
RESULTS
The inter- and intra-observer agreement were 0.98 and 1, respectively. Most instruments demonstrated acceptable performance (scores ≤ 2) in all thirds. Other instruments, such as the HyFlex EDM 25.12 (coronal and middle thirds), Reciproc Blue R25 and Reciproc R25 (coronal and apical thirds), R-Motion 30.04 (apical third), and VDW.ROTATE 20.05 (apical third) showed scores higher than 3. Statistical analysis revealed a significant difference amongst the tested systems at the coronal, middle, and apical thirds (p < .05).
CONCLUSION
None of the canal instrumentation protocols were stress-free, showing varying levels of stress concentrations. Various factors seemed to influence the magnitude of stress and its distribution pattern on the canal walls. Overall, instruments characterized by a larger taper, lower speed, reciprocating motion, and made of heat-treated NiTi alloy exhibited higher patterns of stress distribution.
PubMed: 37566206
DOI: 10.1111/iej.13961 -
Traffic (Copenhagen, Denmark) Dec 2023Epithelial polarity is critical for proper functions of epithelial tissues, tumorigenesis, and metastasis. The evolutionarily conserved transmembrane protein Crumbs...
Epithelial polarity is critical for proper functions of epithelial tissues, tumorigenesis, and metastasis. The evolutionarily conserved transmembrane protein Crumbs (Crb) is a key regulator of epithelial polarity. Both Crb protein and its transcripts are apically localized in epithelial cells. However, it remains not fully understood how they are targeted to the apical domain. Here, using Drosophila ovarian follicular epithelia as a model, we show that epithelial polarity is lost and Crb protein is absent in the apical domain in follicular cells (FCs) in the absence of Diamond (Dind). Interestingly, Dind is found to associate with different components of the dynactin-dynein complex through co-IP-MS analysis. Dind stabilizes dynactin and depletion of dynactin results in almost identical defects as those observed in dind-defective FCs. Finally, both Dind and dynactin are also required for the apical localization of crb transcripts in FCs. Thus our data illustrate that Dind functions through dynactin/dynein-mediated transport of both Crb protein and its transcripts to the apical domain to control epithelial apico-basal (A/B) polarity.
Topics: Animals; Cell Polarity; Drosophila; Drosophila melanogaster; Drosophila Proteins; Dynactin Complex; Dyneins; Epithelial Cells; Membrane Proteins
PubMed: 37642208
DOI: 10.1111/tra.12917 -
Life (Basel, Switzerland) Jul 2023A new hypothesis about the origin of isoetalean lycopsids was proposed based on palynological data. The occurrence of three apical papillae on the proximal surfaces of...
A new hypothesis about the origin of isoetalean lycopsids was proposed based on palynological data. The occurrence of three apical papillae on the proximal surfaces of miospores is a significant palynological feature that is clearly defined in both isoetalean and selaginellalean clades. Three apical papillae appeared for the first time within lower Silurian (Wenlockian ca. 430 My) and only in rhyniophytoid plants. Using this observation, we suggest that isoetalean lycopsids could have evolved directly from rhyniophytoids and not from protolepidodendralean lycopsids in the middle Devonian (Eifelian-Givetian) as previously suggested, because protolepidodendralean spores do not possess three apical papillae. Spores with three apical papillae, reported as dispersed as well as in situ, were recorded continuously from the lower Silurian (Wenlockian) through the Devonian, Carboniferous, Permian, Mesozoic to Cenozoic era and form a phylogenetically independent lineage.
PubMed: 37511920
DOI: 10.3390/life13071546