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BMC Oral Health Apr 2024Dentin hypersensitivity, often occurring after dental treatments or from erosive lesions, is a prevalent patient complaint. This study introduces a paste combining 8%... (Randomized Controlled Trial)
Randomized Controlled Trial Comparative Study
Evaluation and comparison of the effects of a new paste containing 8% L-Arginine and CaCO3 plus KNO3 on dentinal tubules occlusion and dental sensitivity: a randomized, triple blinded clinical trial study.
BACKGROUND
Dentin hypersensitivity, often occurring after dental treatments or from erosive lesions, is a prevalent patient complaint. This study introduces a paste combining 8% L-arginine, calcium carbonate, and potassium nitrate to evaluate its impact on dentinal tubules occlusion, dentin permeability, and tooth sensitivity.
METHODS
Dentin surfaces from 24 third molars (thickness: 2 mm) were divided into two groups of 12. One received the experimental paste, while the other received a placebo without desensitizer. Permeability and sealing ability were assessed through scanning electron microscopy (SEM) and dentin permeability measurement. The pastes' effects on hypersensitivity were then examined in a triple-blind, randomized parallel-armed clinical trial with 16 eligible patients. Sensitivity to cold, touch, and spontaneous stimuli was recorded using the VAS scale at various intervals post-treatment. Statistical analysis was conducted using Shapiro-Wilk, Mann-Whitney U, Friedman, and Wilcoxon tests (α = 0.05).
RESULTS
The permeability test demonstrated a significant reduction in dentin permeability in the experimental group (P = 0.002) compared to the control (P = 0.178). SEM images revealed most dentinal tubules in the intervention samples to be occluded. Clinically, both groups showed a significant decrease in the three types of evaluated sensitivity throughout the study. However, no significant difference in sensitivities between the two groups was observed, with the exception of cold sensitivity at three months post-treatment (P = 0.054).
CONCLUSION
The innovative desensitizing paste featuring 8% L-arginine, calcium carbonate, and potassium nitrate effectively occluded dentinal tubules and reduced dentin permeability. It mitigated immediate and prolonged dentin hypersensitivity to various stimuli, supporting its potential role in managing dentin hypersensitivity.
TRIAL REGISTRATION
http://irct.ir : IRCT20220829055822N1, September 9th, 2022.
Topics: Humans; Dentin Sensitivity; Arginine; Calcium Carbonate; Nitrates; Male; Female; Potassium Compounds; Dentin Desensitizing Agents; Adult; Microscopy, Electron, Scanning; Dentin Permeability; Dentin; Toothpastes; Young Adult; Middle Aged
PubMed: 38685035
DOI: 10.1186/s12903-024-04298-3 -
Journal of Dentistry Jul 2024This study evaluated the reliability of a face scanner in measuring the vertical dimension of occlusion (VDO).
OBJECTIVE
This study evaluated the reliability of a face scanner in measuring the vertical dimension of occlusion (VDO).
METHODS
Fully dentate volunteers (n = 20; mean-age = 30.0 ± 10.7 years) were recruited. Clinical facial measurements were obtained using a digital caliper and a face scanner (Obiscanner, Fifthingenium, Italy). The scans were imported into a mesh-processing software, and the distances were measured digitally. Measurements were obtained for each participant with the jaws positioned in maximal intercuspation (MI) and with increased vertical distances of 2, 4, and 6 mm. Vertical and horizontal measures were obtained using facial anatomical landmarks: Glabella (GL), Pronasale (PrN), Subnasale (SbN), inferior border of the right and left Alare, Labiale superius (Ls), right and left Cheilion (Ch), Soft Pogonion (SPg), right and left Tragus of the ear (Tr), for all selected vertical positions. Data analysis included intra-class correlation coefficient (ICC), pairwise comparison tests, Bland-Altman plots, and Passing-Bablok regression.
RESULTS
120 VDO measurements (clinical=60, digital=60) were recorded by two independent evaluators. Mean differences between digital and clinical measurements ranged from 0.054 ± 0.14 mm to 0.203 ± 0.13 mm. All parameters were strongly correlated (r > 0.93; p < 0.001). ICC estimates revealed excellent reliability, and the measuring procedure yielded the same results on repeated trials irrespective of the raters and measurement methods. Bland-Altman plots revealed a difference, between digital and clinical measurements, of 1.7 % for the vertical measurements. Regression analysis revealed no significant proportional difference between the two methods, so both can be used interchangeably.
CONCLUSIONS
The findings of this study demonstrate that VDO can be measured accurately from face scans using 3D mesh-processing software and that even small changes in the VDO could be detected using the digital methods.
CLINICAL SIGNIFICANCE
Findings provide evidence about the reliability of a digital method for jaw relation registrations and may be applied towards incorporating this method into clinical workflows for computer-aided-design/ computer-assisted-manufacturing (CAD-CAM) dentures.
Topics: Humans; Adult; Reproducibility of Results; Vertical Dimension; Male; Female; Face; Young Adult; Cephalometry; Image Processing, Computer-Assisted; Anatomic Landmarks; Dental Occlusion; Software; Imaging, Three-Dimensional; Lip; Nose; Middle Aged
PubMed: 38679136
DOI: 10.1016/j.jdent.2024.105016 -
Children (Basel, Switzerland) Apr 2024Early mixed dentition represents a critical phase since crowding conditions can occur. The interceptive resolution of dental crowding allows favorable arch and occlusal...
BACKGROUND
Early mixed dentition represents a critical phase since crowding conditions can occur. The interceptive resolution of dental crowding allows favorable arch and occlusal development. The aim of the present investigation was to evaluate dentoalveolar changes of clear aligner treatment planned to manage lower incisor crowding, loss of arch length, and midline deviation in early mixed dentition.
METHODS
A total of 13 patients (7 females, 6 males, 9.4 ± 1.2 age) treated with clear aligners were selected. Arch dimensions and incisor inclinations were evaluated before (T0) and at the end of interceptive treatment (T1). A paired -test was chosen to compare T1-T0 changes. The level of significance was set at 5%.
RESULTS
The greatest significant increase in mandibular width was observed at the level of the first deciduous molars (+2.44 ± 1.4 mm), followed by the second permanent molars (+2.16 ± 1.4 mm). Lower arch length and arch depth showed a statistically relevant increase (2 ± 0.6 mm and 4.5 ± 1.6 mm, respectively). The mean lower dental midline changes were statistically significant (1.42 ± 0.73 mm).
CONCLUSIONS
Early treatment with clear aligners, including the combination of transversal arch development, maintenance of leeway space, and guidance of eruption, represents a valid treatment strategy in early mixed dentition to manage arch crowding and occlusion development.
PubMed: 38671668
DOI: 10.3390/children11040451 -
Scientific Reports Apr 2024Analyzing the correlation between cephalometric measurements is important for improving our understanding of the anatomy in the oral and maxillofacial region. To...
Analyzing the correlation between cephalometric measurements is important for improving our understanding of the anatomy in the oral and maxillofacial region. To minimize bias resulting from the design of the input data and to establish a reference for malocclusion research, the aims of this study were to construct the input set by integrating nine cephalometric analyses and to study the correlation structure of cephalometric variables in Korean adults with normal occlusion. To analyze the complex correlation structure among 65 cephalometric variables, which were based on nine classical cephalometric analyses, network analysis was applied to data obtained from 735 adults (368 males, 367 females) aged 18-25 years with normal occlusion. The structure was better revealed through weighted network analysis and minimum spanning tree. Network analysis revealed cephalometric variable clusters and the inter- and intra-correlation structure. Some metrics were divided based on their geometric interpretation rather than their clinical significance. It was confirmed that various classical cephalometric analyses primarily focus on investigating nine anatomical features. Investigating the correlation between cephalometric variables through network analysis can significantly enhance our understanding of the anatomical characteristics in the oral and maxillofacial region, which is a crucial step in studying malocclusion using artificial intelligence.
Topics: Humans; Cephalometry; Male; Female; Adult; Adolescent; Republic of Korea; Young Adult; Dental Occlusion; East Asian People
PubMed: 38671196
DOI: 10.1038/s41598-024-60410-1 -
Dentistry Journal Apr 2024By correctly repositioning teeth, orthodontic therapy improves both the function and appearance of an occlusion. The relationship between teeth and the tissues that... (Review)
Review
By correctly repositioning teeth, orthodontic therapy improves both the function and appearance of an occlusion. The relationship between teeth and the tissues that surround and support them significantly influences these alterations. With ever more adults seeking orthodontic care, orthodontists are increasingly seeing patients with periodontal issues. Concerns about the patient's appearance, such as uneven gingival margins or functional issues caused by inflammatory periodontal diseases, should be accounted for when designing orthodontic treatment plans. Furthermore, orthodontics may increase the chances of saving and recovering a degraded dentition in cases of severe periodontitis. Today, general dentists, dontists, and orthodontists play integrative roles that enable them to achieve the best possible results for their patients. This review will improve the results of interdisciplinary treatments and increase cooperation between dental specialists by drawing attention to the essential connection between orthodontics and periodontics in regular clinical practice.
PubMed: 38668024
DOI: 10.3390/dj12040112 -
Cells Apr 2024Ischemic stroke is a major cerebrovascular disease with high morbidity and mortality rates; however, effective treatments for ischemic stroke-related neurological...
Human-Induced Pluripotent Stem Cell-Derived Neural Progenitor Cells Showed Neuronal Differentiation, Neurite Extension, and Formation of Synaptic Structures in Rodent Ischemic Stroke Brains.
Ischemic stroke is a major cerebrovascular disease with high morbidity and mortality rates; however, effective treatments for ischemic stroke-related neurological dysfunction have yet to be developed. In this study, we generated neural progenitor cells from human leukocyte antigen major loci gene-homozygous-induced pluripotent stem cells (hiPSC-NPCs) and evaluated their therapeutic effects against ischemic stroke. hiPSC-NPCs were intracerebrally transplanted into rat ischemic brains produced by transient middle cerebral artery occlusion at either the subacute or acute stage, and their in vivo survival, differentiation, and efficacy for functional improvement in neurological dysfunction were evaluated. hiPSC-NPCs were histologically identified in host brain tissues and showed neuronal differentiation into vGLUT-positive glutamatergic neurons, extended neurites into both the ipsilateral infarct and contralateral healthy hemispheres, and synaptic structures formed 12 weeks after both acute and subacute stage transplantation. They also improved neurological function when transplanted at the subacute stage with γ-secretase inhibitor pretreatment. However, their effects were modest and not significant and showed a possible risk of cells remaining in their undifferentiated and immature status in acute-stage transplantation. These results suggest that hiPSC-NPCs show cell replacement effects in ischemic stroke-damaged neural tissues, but their efficacy is insufficient for neurological functional improvement after acute or subacute transplantation. Further optimization of cell preparation methods and the timing of transplantation is required to balance the efficacy and safety of hiPSC-NPC transplantation.
Topics: Induced Pluripotent Stem Cells; Humans; Animals; Neural Stem Cells; Cell Differentiation; Ischemic Stroke; Rats; Synapses; Male; Neurites; Brain; Brain Ischemia; Neurons; Rats, Sprague-Dawley; Stroke
PubMed: 38667286
DOI: 10.3390/cells13080671 -
Materials Today. Bio Jun 2024Periodontal ligament (PDL) cells play a crucial role in maintaining periodontal integrity and function by providing cell sources for ligament regeneration. While...
Periodontal ligament (PDL) cells play a crucial role in maintaining periodontal integrity and function by providing cell sources for ligament regeneration. While biophysical stimulation is known to regulate cell behaviors and functions, its impact on epigenetics of PDL cells has not yet been elucidated. Here, we aimed to investigate the cytoskeletal changes, epigenetic modifications, and lineage commitment of PDL cells following the application of stretch stimuli to PDL. PDL cells were subjected to stretching (0.1 Hz, 10 %). Subsequently, changes in focal adhesion, tubulin, and histone modification were observed. The survival ability in inflammatory conditions was also evaluated. Furthermore, using a rat hypo-occlusion model, we verified whether these phenomena are observed . Stretched PDL cells showed maximal histone 3 acetylation (H3Ace) at 2 h, aligning perpendicularly to the stretch direction. RNA sequencing revealed stretching altered gene sets related to mechanotransduction, histone modification, reactive oxygen species (ROS) metabolism, and differentiation. We further found that anchorage, cell elongation, and actin/microtubule acetylation were highly upregulated with mechanosensitive chromatin remodelers such as H3Ace and histone H3 trimethyl lysine 9 (H3K9me3) adopting euchromatin status. Inhibitor studies showed mechanotransduction-mediated chromatin modification alters PDL cells behaviors. Stretched PDL cells displayed enhanced survival against bacterial toxin (C12-HSL) or ROS (HO) attack. Furthermore, cyclic stretch priming enhanced the osteoclast and osteoblast differentiation potential of PDL cells, as evidenced by upregulation of lineage-specific genes. , PDL cells from normally loaded teeth displayed an elongated morphology and higher levels of H3Ace compared to PDL cells with hypo-occlusion, where mechanical stimulus is removed. Overall, these data strongly link external physical forces to subsequent mechanotransduction and epigenetic changes, impacting gene expression and multiple cellular behaviors, providing important implications in cell biology and tissue regeneration.
PubMed: 38654935
DOI: 10.1016/j.mtbio.2024.101050 -
American Journal of Veterinary Research Jul 2024To evaluate the kinematics and stability of the temporomandibular joint (TMJ) of cats and dogs with and without a TMJ replacement (TMJR) prosthesis under simulated bite...
OBJECTIVE
To evaluate the kinematics and stability of the temporomandibular joint (TMJ) of cats and dogs with and without a TMJ replacement (TMJR) prosthesis under simulated bite forces and mouth opening.
ANIMALS
Sixteen cadaver skulls from domestic cats (n = 8) and medium- to large-breed dogs (n = 8).
METHODS
Intact TMJs were tested. Following condylectomy and coronoidectomy, the skulls were fitted with a TMJR prosthesis unilaterally and retested. Prosthesis was similarly implanted in the contralateral TMJ in 4 cats and 4 dogs before retesting. Left and right bite motions were evaluated before bite contact to peak bite force (200 N in dogs, 63 N in cats). Mouth opening motion was recorded. Mandibular displacement under load was evaluated in 3 orthogonal planes. Maximal displacement was compared between TMJR groups and native TMJ. Prosthesis-bone motion of the temporal and mandibular components was evaluated during simulated bites and mouth opening.
RESULTS
TMJR resulted in joint motion not demonstrably different from the native TMJ, with the ability to fully open and close the mouth and with minimal laterotrusion. The TMJR prosthesis demonstrated similar stability after unilateral and bilateral replacement during bite force and with an open mouth. Mean implant-bone motion during bite simulations for the temporal and mandibular TMJR components was ≤ 60 µm in cats and ≤ 30 µm in dogs.
CLINICAL RELEVANCE
A novel TMJR can be implanted and allows normal jaw motion. Joint stability is maintained after TMJR implantation in the TMJ of dogs and cats TMJ that is devoid of muscular support.
Topics: Animals; Dogs; Cats; Temporomandibular Joint; Biomechanical Phenomena; Bite Force; Joint Prosthesis; Cadaver; Arthroplasty, Replacement; Temporomandibular Joint Disorders
PubMed: 38640955
DOI: 10.2460/ajvr.24.01.0009 -
Computer Methods and Programs in... Jun 2024Advanced cases of head and neck cancer involving the mandible often require surgical removal of diseased sections and subsequent replacement with donor bone. During the...
STATEMENT OF PROBLEM
Advanced cases of head and neck cancer involving the mandible often require surgical removal of diseased sections and subsequent replacement with donor bone. During the procedure, the surgeon must make decisions regarding which bones or tissues to resect. This requires balancing tradeoffs related to issues such as surgical access and post-operative function; however, the latter is often difficult to predict, especially given that long-term functionality also depends on the impact of post-operative rehabilitation programs.
PURPOSE
To assist in surgical decision-making, we present an approach for estimating the effects of reconstruction on key aspects of post-operative mandible function.
MATERIAL AND METHODS
We develop dynamic biomechanical models of the reconstructed mandible considering different defect types and validate them using literature data. We use these models to estimate the degree of functionality that might be achieved following post-operative rehabilitation.
RESULTS
We find significant potential for restoring mandibular functionality, even in cases involving large defects. This entails an average trajectory error below 2 mm, bite force comparable to a healthy individual, improved condyle mobility, and a muscle activation change capped at a maximum of 20%.
CONCLUSION
These results suggest significant potential for adaptability in the masticatory system and improved post-operative rehabilitation, leading to greater restoration of jaw function.
Topics: Humans; Mastication; Mandibular Reconstruction; Mandible; Computer Simulation; Biomechanical Phenomena; Bite Force
PubMed: 38640839
DOI: 10.1016/j.cmpb.2024.108174 -
Cureus Mar 2024This case report explores how the presence of an adjacent implant influenced the restoration of a tooth with pulpitis in a gastro-esophageal reflux disease (GERD)...
This case report explores how the presence of an adjacent implant influenced the restoration of a tooth with pulpitis in a gastro-esophageal reflux disease (GERD) patient. A patient with GERD requires a tooth-colored crown not only for aesthetics but also to address potential galvanic concerns arising from an adjacent implant. GERD, a condition causing non-cavity erosion, weakens tooth structure over time, presenting significant challenges in treatment. It resulted in bite relapse and insufficient occlusal clarity over time. A comprehensive treatment approach was needed to restore both function and appearance. This involved managing galvanism using non-metallic materials to ensure optimal occlusal clarity, as well as meticulously reinforcing and restoring tooth structure. Monoblock post-fused crowns were chosen for their superior durability, stability, and comfort. The ceramic layering not only effectively prevented galvanic issues by insulating the tooth structure but also significantly improved the natural appearance of teeth, thereby promoting long-term oral health and successfully managing complex dental concerns. The dental team successfully restored the damaged tooth by considering specific factors that influenced the treatment plan, including achieving optimal aesthetic outcomes.
PubMed: 38638723
DOI: 10.7759/cureus.56482