Hasil untuk "Dentistry"

Jungwook Koh, Young Ho Kim, Namgi Kim et al.

Abstract This study focused on developing a machine learning (ML) model to forecast the success of camouflage orthodontic treatment in individuals with skeletal Class III malocclusion and to identify significant predictors to aid treatment planning. A total of 100 adult patients who had skeletal Class III malocclusion and were treated with camouflage orthodontics were analyzed retrospectively. Treatment success was defined by an overjet exceeding 2 mm, proper canine relationship, and appropriate molar relationship (as applicable). Four machine learning algorithms (Random Forest, CART, Neural Network, and XGBoost) were trained and evaluated using fivefold cross-validation. Cephalometric variables were analyzed before and after treatment, and model performance was evaluated. Among all metrics, XGBoost exhibited the best predictive performance, suggesting better generalization. A decision tree model showed that the sagittal position of the lower incisors (L1_x) and palatal length (Palatal L) were the most influential predictors. An L1_x of less than 76 mm and a Palatal L of 41 mm or greater were strongly associated with successful treatment. ML algorithms, particularly XGBoost, can forecast the effectiveness of camouflage treatment for skeletal Class III malocclusion. Key predictors can guide treatment planning and support artificial intelligence-assisted orthodontic decisions.

Gianmario Schierano, Domenico Baldi, Cristina Bignardi et al.

This study evaluated the efficiency and potential risks associated with three clinical tools for removing cement-retained implant-supported prostheses: Magnetic Mallet, sliding hammer, and Coronaflex. The tests consisted of: cementation of three-unit bridge models onto titanium abutments with different geometries using Zinc Oxide non-eugenol or Zinc Phosphate cement. Seven different geometries of three-unit bridges were tested; therefore, a total of 7 bridges × 2 luting agents × 3 tools were combined in a full factorial analysis. Five test replicates were performed for each combination, resulting in a total of 5 × 7 × 2 × 3 = 210 retrieval tests. The 70 tests regarding the Coronaflex were taken from a previously conducted experiment on the topic, using the same dental bridge models and the same experimental conditions. Efficiency was assessed by the percentage of successful removals and the maximum force recorded with a piezoelectric load cell. For temporary cementations, the sliding hammer achieved the highest retrieval rate, while the Magnetic Mallet demonstrated comparable efficiency with lower forces. Coronaflex showed lower success rates and higher forces than Magnetic Mallet. For permanent cementations, most bridges were not removable, and attempts with the sliding hammer occasionally resulted in abutment screw damage. Within the limitations of this study, the Magnetic Mallet appears to be an effective option for removing bridges cemented with temporary cement, potentially in combination with a sliding hammer for highly retentive geometries. Zinc phosphate cement should be avoided when retrievability is desired, except for abutments with very low retention capability.

Amira El-Najjar, Khaled Nour, Aya Samaha et al.

Abstract Background The optical properties of composite restorations are influenced by composite’s surface conditions and polishing techniques, which can affect stain resistance. This study examined how surface condition and polishing techniques affect the color stability of two composite restorative materials. Methods A total of 150 composite discs were divided into 30 experimental groups (n = 5) based on composite material (ormocer-based composite, Admira Fusion, and methacrylate-based composite’ Grandio), surface condition (against matrix, air, or glycerin), and polishing technique (No polishing, 1-step, 2-step, abrasive + one-step, and abrasive + two-step). Color measurements were taken using a spectrophotometer before immersion (baseline) and after 3 months of immersion in a coffee solution. Data were analyzed using ANOVA and Tukey HSD test (α = 0.05). Result Composite type, surface condition, and polishing technique all had a significant effect on ΔE (P < 0.001). Admira Fusion and Grandio exhibited the lowest ΔЕ value (3.26 ± 0.15, 3.43 ± 0.08 respectively) when polished with abrasives and a 2-step technique (P < 0.05). Grandio showed the highest ΔЕ value (19.66 ± 0.37) when light cured in air and without exposure to any polishing technique (P < 0.05). Conclusion The color stability of composites was enhanced by applying glycerin coatings prior to light curing and polishing.

Guomin Wu

Aim or purpose: This study aims to addresses the critical limitations of conventional hydrogels in cartilage tissue engineering—inadequate porosity and suboptimal mechanical strength. Materials and methods: The materials used in this study include methacrylated silk fibroin (SilMA), poly(ethylene oxide) (PEO) as a sacrificial template, and homogenized electrospun silk fibroin nanofibers (NFs).A water-in-water emulsification strategy was employed to create the porous architecture using PEO as a sacrificial template. Homogenized NFs were incorporated into the bioink at different weight percentages (1-2 wt%). The hydrogel's structural modulation, compressive strength, elastic modulus, 3D printability, biocompatibility, and cartilage-related gene expression were evaluated.In vivo experiments were conducted to confirm the efficacy of the developed hydrogel in promoting cartilage regeneration. Results: The pore-forming process resulted in remarkable structural modulation, achieving over 100% increase in average pore diameter and 75% enhancement in overall porosity compared to non-porous counterparts. However, this structural modification compromised the compressive modulus by approximately 25%. The introduction of NFs (1-2 wt%) not only recovered the compressive strength and elastic modulus (near to SilMA hydrogels) but also improved the 3D printability of SilMA/PEO hydrogels. Furthermore, the hydrogels demonstrated excellent biocompatibility and markedly upregulated cartilage-related gene expression, including Collagen II, Aggrecan and Sox9. Conclusions: This study successfully developed a dual-strategy approach for cartilage tissue engineering by integrating NFs reinforcement and PEO-induced porosity. The innovative cell-laden porous SilMA hydrogel system demonstrated significant improvements in structural properties, mechanical strength, biocompatibility.

Karoline Sørensen, Kristian H. Lind, Einar Berg et al.

ABSTRACT Suboptimal incision lines and a bone dehiscence exposure complicated the surgical outcome following a mandibular frenectomy in a previously orthodontically treated patient. The case report describes the surgical intervention used to treat the complication and documents the long‐term stability of periodontal health, complete root coverage, and thick gingival phenotype status.

Yamato Okada, Nobuyuki Kawashima, Sonoko Noda et al.

Background/purpose: Vascular endothelial growth factor A (VEGFA) is a potent angiogenic factor and an essential growth factor for vascular endothelial cells, but its effects on dental pulp stem cells, such as stem cells from human exfoliated deciduous teeth (SHEDs), have not been fully evaluated. The aim of this study was to explore the effects and underlying mechanisms of VEGFA on odonto/osteoblastic differentiation in SHEDs in vitro. This study also aimed to examine the mineralized tissue-forming and pro-angiogenic potentials of VEGFA in rat dental pulp in vivo. Materials and methods: Proliferation, migration, odonto/osteoblastic gene expression, and mineralized nodule formation were evaluated in SHEDs after stimulation with recombinant human VEGFA (rhVEGFA). Expression patterns of extracellular signal-regulated kinase (ERK) and p38/mitogen-activated protein kinase (MAPK) were analysed by western blotting. Rat molar pulp was histologically and immunohistochemically examined after 10 days of rhVEGFA-soaked agarose bead exposure. Results: rhVEGFA stimulation promoted migration, mRNA expression of odonto/osteoblastic markers RUNX family transcription factor 2 (RUNX2) and alkaline phosphatase (ALP), and mineralized nodule formation in SHEDs; these effects were reduced by ERK and p38/MAPK inhibitors. RhVEGFA-treated rat molar pulp tissues exhibited a reparative dentin-like mineralized tissue with surrounding nestin-positive cells and densely distributed CD146+ vascular vessels. Conclusion: rhVEGFA can promote migration, odonto/osteoblastic differentiation, and mineralized nodule formation via ERK/p38 signaling in SHEDs in vitro; it promotes mineralized tissue formation and neovascularization in pulp tissue in vivo.

Yomna E. Dean, Sameh Samir Elawady, Wangpan Shi et al.

Abstract Background and Aim Low serum Vitamin D levels have been associated with diabetic nephropathy (DN). Our study aimed to analyse the serum levels of vitamin D in patients suffering from DN and the subsequent changes in serum vitamin D levels as the disease progresses. Methods PubMed, Embase, SCOPUS and Web of Science were searched using keywords such as ‘25 hydroxyvitamin D’ and ‘diabetic nephropathy’. We included observational studies that reported the association between the serum 25 hydroxy vitamin D levels and diabetic nephropathy without restriction to age, gender, and location. R Version 4.1.2 was used to perform the meta‐analysis. The continuous outcomes were represented as mean difference (MD) and standard deviation (SD) and dichotomous outcomes as risk ratios (RR) with their 95% confidence interval (CI). Results Twenty‐three studies were included in our analysis with 7722 patients. Our analysis revealed that vitamin D was significantly lower in diabetic patients with nephropathy than those without nephropathy (MD: −4.32, 95% CI: 7.91–0.74, p‐value = .0228). On comparing diabetic patients suffering from normoalbuminuria, microalbuminuria, or macroalbuminuria, we found a significant difference in serum vitamin D levels across different groups. Normoalbuminuria versus microalbuminuria showed a MD of −1.69 (95% CI: −2.28 to −1.10, p‐value = .0002), while microalbuminuria versus macroalbuminuria showed a MD of (3.75, 95% CI: 1.43–6.06, p‐value = .0058), proving that serum vitamin D levels keep declining as the disease progresses. Notwithstanding, we detected an insignificant association between Grade 4 and Grade 5 DN (MD: 2.29, 95% CI: −2.69–7.28, p‐value = .1862). Conclusion Serum Vitamin D levels are lower among DN patients and keep declining as the disease progresses, suggesting its potential benefit as a prognostic marker. However, on reaching the macroalbuminuria stage (Grades 4 and 5), vitamin D is no longer a discriminating factor.

Yo Akiyama, Maiko Iwaki, Yuriko Komagamine et al.

Milling machines have made denture fabrication possible with high accuracy in a short time. However, the relationship between the milling conditions, accuracy, and milling duration has not been clarified. This study aimed to clarify the effects of milling conditions on surface roughness and milling duration. The specimen was designed using CAD software and milled using PMMA disks. In milling, the parameters of finishing the specimen surface were adjusted. Three different spindle speeds and four different feed rates were set. Twelve combinations of each parameter were used for milling, and the surface roughness and milling duration were measured. Results showed that the surface roughness significantly increased with the feed rate on the slopes of the specimen. The surface roughness differed with the spindle speed on the left and right slopes. The spindle speed and feed rate did not affect the surface roughness on the flat surface. The milling duration was not affected by the spindle speed but decreased as the feed rate increased. In conclusion, by increasing both the spindle speed and feed rate, the milling duration could be shortened while maintaining a constant surface quality. The optimum milling conditions were a spindle speed of 40,000 rpm and feed rate of 3500 mm/min.

Julia Seretny, Tara Pidborochynski, Holger Buchholz et al.

Carlos Suárez-Canlla, Hugo Caballero-Cornejo, Jorge Mezzich-Gálvez et al.

Objetivo. Comparar la eficacia de tres métodos dentales (Demirjian, Gleiser-Hunt modificado y análisis morfométrico) para estimar la edad de personas de 13 a 23 años a partir del desarrollo radicular de los terceros molares inferiores. Métodos. La muestra estuvo conformada por 978 ortopantomografías de personas con edad cronológica y sexo (484 varones y 494 mujeres) conocidos. El desarrollo radicular de las molares fue clasificado según los métodos señalados. Se tomó el 10% de la muestra para una segunda clasificación que permitió establecer la concordancia entre ellas. Se correlacionaron los estadios de desarrollo radicular – obtenidos con los métodos mencionados – y la edad cronológica para obtener: 1) el índice de correlación y determinación 2) las fórmulas de regresión que predicen la edad y 3) la diferencia entre la edad cronológica real y la edad dental estimada para cada uno de los métodos. Resultados. El método Gleiser-Hunt modificado obtuvo el menor residual que fue resultado de la diferencia entre la edad cronológica y dental, así como el mejor índice de correlación con la edad cronológica. La diferencia entre la edad cronológica y dental fue de 1,55, 1,68 y 2,11 para los métodos Gleiser-Hunt modificado, Demirjian y análisis morfométrico respectivamente. Conclusiones. El método Gleiser-Hunt modificado resultó más eficaz para predecir la edad de personas e individuos de 13 a 23 años.

Ollie Yiru Yu, Walter Yu-Hang Lam, Amy Wai-Yee Wong et al.

The World Dental Federation (FDI) policy statement in 2016 advocated evidence-based caries-control measures for managing dental caries. The caries management philosophy has shifted from the traditional surgical manners to minimal intervention dentistry. Minimal intervention dentistry aims to extend the longevity of natural teeth. It places the nonrestorative approaches as a priority. The nonrestorative approaches for caries management aim to tackle the etiological factors of dental caries. Caries can be prevented or reversed by restricting the sugar intake and its frequency in the diet, improving oral hygiene practices, and using fluoride toothpaste. This article aims to present strategies for the nonrestorative management of dental caries, which are divided into four components to address the different etiological factors of dental caries. The first component is controlling dental plaque. Strategies for plaque control include oral hygiene instruction, motivational interviewing, mechanical plaque control, and chemical plaque control. The second component for nonrestorative management is reducing the risk of caries by identifying caries risk factors and protective factors, assessing personal caries risk, and customizing a treatment plan. Evidence-based measures for caries prevention include using fluoride, and dental sealants should be provided. The third component includes topical treatment to remineralise early carious lesions. The last component is long-term follow-up. Appropriate strategy adoption for the nonrestorative management of dental caries prolongs the life span of the teeth and sustains the good oral health of patients.

Muhammad Zaal Haq, Anggraini Margono, R. A. H. Nilakesuma Djauharie et al.

Objective: To compare Transforming growth factor-β1 (TGF-β1) expression in various L-PRF concentrations on the hDPSC differentiation process. Material and Methods: hDPSC cell cultures were subjected to serum starvation by reducing FBS levels in the hDPSC culture media. Lysate PRF was obtained from the PRF gel, which was then incubated at 4°C for 24 h. The supernatant was dried, transferred to a 2-ml Eppendorf tube, and stored at −20°C. The evaluation of TGF-β1 expression in 1%, 5%, 10%, and 25% L-PRF samples and 10% FBS (control) during the process of hDPSC differentiation was quantified using an ELISA reader on day 7. The expression of TGF-β1 was subjected to a one-way ANOVA test, followed by Bonferroni’s post hoc test with significant values (p<0.05). Results: Significant differences were noted in TGF-β1 expression between 1%, 5%, 10%, and 25% L-PRF and the control group (10% FBS). The highest TGF-β1 expression occurred with 25% L-PRF (0.645 ± 0.048), followed by 10% L-PRF (0.461 ± 0.035), 10% FBS (0.374 ± 0.013), 5% L-PRF (0.275 ± 0.045), and the lowest expression was with 1% L-PRF (0.160 ± 0.045). Conclusion: The best result of TGF-B1 expression in hDPSC differentiation was in the 25% L-PRF group.

María José Monsalva Cerda, Magdalena Rodriguez Verdugo, Andrea Ormeño Quintana

Roman Tikhomirov, Benedict Reilly-O’ Donnell, Francesco Catapano et al.

Fibrosis is a significant global health problem associated with many inflammatory and degenerative diseases affecting multiple organs, individually or simultaneously. Fibrosis develops when extracellular matrix (ECM) remodeling becomes excessive or uncontrolled and is associated with nearly all forms of heart disease. Cardiac fibroblasts and myofibroblasts are the main effectors of ECM deposition and scar formation. The heart is a complex multicellular organ, where the various resident cell types communicate between themselves and with cells of the blood and immune systems. Exosomes, which are small extracellular vesicles, (EVs), contribute to cell-to-cell communication and their pathophysiological relevance and therapeutic potential is emerging. Here, we will critically review the role of endogenous exosomes as possible fibrosis mediators and discuss the possibility of using stem cell-derived and/or engineered exosomes as anti-fibrotic agents.

V. K. Kapitanova, N. E. Petrova, M. Yu. Zhdanova et al.

Allergic reactions associated with sensitisation to metals are a common but underexplored problem. Due to the frequent use of metals and their alloys there has been an increase in the number of registered cases of allergic reactions. Recently there have been cases when allergic reactions were induced by metals that were previously considered absolutely inert and non-allergenic, such as gold, palladium and others. The aim of this work was to summarise scientific data on allergic reactions to metals and their diagnosis in humans. In medicine, alloys of nickel, palladium and gold are used in the manufacture of both surgical instruments and various implants used in orthopedics, endovascular surgery, gynecology and dentistry. Allergic reactions to these metals may lead to failure of artificial joints, thrombosis of endovascular stents, stomatitis, gingivitis, and dermatitis. The most frequent allergic reaction to metals is contact dermatitis which is most frequently caused by nickel. Metal allergies are diagnosed by skin tests. There are no Russian-made diagnostic systems for detecting metal allergies. The diagnosis of allergic contact dermatitis is performed with the help of AllerTest test kit («TRUE Test», Denmark). Therefore, elaboration of a domestic diagnostic test for timely detection of allergies to metals is still relevant.

Azadeh Horri, Saeed Hajmohammadi, Homa Kamyabi et al.

BACKGROUND AND AIM: Individual’s learning style determines the mechanism of processing, internalization, and retention of new information. The higher education centers and professors need information and conformity to various learning styles to help students learn effectively. In addition, researchers believe that learning styles are one of the factors responsible for differences in students’ academic performance. METHODS: The sample of present study consisted of all the first-year to sixth-year dental students and the postgraduate students of School of Dentistry, Kerman University of Medical Sciences, Kerman, Iran, in the second semester of 2016–2017. The subjects were included in the study using the census method (343 undergraduate and 59 postgraduate students). Data were collected using VARK questionnaire. The students’ overall mean grades were used to evaluate their academic performance. The data were analyzed with SPSS software; also descriptive statistics (frequencies, central indices, and distribution) and analytical statistics were used. The correlation between learning style and the average of the students was evaluated with analysis of variance (ANOVA) test and chi-square test was used to evaluate the relationship of learning styles with age, gender, and grades of education. RESULTS: 88.3% of the learners were unimodal and 11.7% used multi-modal learning style. No statistical correlation between the students’ learning style and their academic performance was found (P = 0.066). CONCLUSION: The professors should be aware of the different preferences of students in learning styles and take the necessary steps to develop effective educational techniques that fit the students’ learning styles.

Anna Wiersma, Ian Winship

The photothrombotic model of stroke is commonly used in research as it allows the ischemic infarct to be targeted to specific regions of the cortex with high reproducibility and well-defined infarct borders. Unlike other models of stroke, photothrombosis allows the precise size and location of infarct to be tightly controlled with minimal surgical invasion. Photothrombosis is induced when a circulating photosensitive dye is irradiated in vivo, resulting in focal disruption of the endothelium, activation of platelets and occlusion of the microvasculature (Watson et al., 1985; Dietrich et al., 1987; Carmichael, 2005). The protocols here define how photothrombosis can be specifically targeted to the sensorimotor forelimb cortex of rat with high reproducibility. Detailed methods on rat cortical tissue processing to allow for accurate analysis of stroke volume and stereotactic determination of the precise cortical region of ischemic damage are provided.

E.S. Stolyarevich, L.Y. Artyukhina, I.G. Kim et al.

Rejection has always been one of the most important cause of late renal graft dysfunction. Aim of the study was to analyze the prevalence of different clinico-pathological variants of rejection that cause late graft dysfunction, and evaluate their impact on long-term outcome. Materials and methods. This is a retrospective study that analyzed 294 needle core biopsy specimens from 265 renal transplant recipients with late (48,8 ± 46,1 months after transplantation) allograft dysfunction caused by late acute rejection (LAR, n = 193) or chronic rejection (CR, n = 78) or both (n = 23). C4d staining was performed by immunofl uorescence (IF) on frozen sections using a standard protocol. Results. Peritubular capillary C4d deposition was identifi ed in 36% samples with acute rejection and in 62% cases of chronic rejection (including 67% cases of transplant glomerulopathy, and 50% – of isolated chronic vasculopathy). 5-year graft survival for LAR vs CR vs their combination was 47, 13 and 25%, respectively. The outcome of C4d– LAR was (p &lt; 0,01) better than of C4d+ acute rejection: at 60 months graft survival for diffuse C4d+ vs C4d− was 33% vs 53%, respectively. In cases of chronic rejection C4d+ vs C4d– it was not statistically signifi cant (34% vs 36%). Conclusion. In long-term allograft biopsy C4d positivity is more haracteristic for chronic rejection than for acute rejection. Only diffuse C4d staining affects the outcome. C4d– positivity is associated with worse allograft survival in cases of late acute rejection, but not in cases of chronic rejection.

M. Kukletová, L. Pantuček, Z. Halačková et al.

Introduction: A proportion of preschool children with high caries experience (i.e. with early childhood caries, EEC) has been growing over the recent years in the Czech Republic and other countries. These high-risk children are often difficult to treat at standard dental office, especially if they have concomitant medical problems. The aim of the study was to evaluate dental status of preschool children referred to our department for treatment under general anaesthesia. Materials and Methods: In 2002-2004, totally 111 children below the age of six were referred for dental treatment under general anaesthesia (GA) to Dental clinic of the St. Ann's University Hospital Brno. Dental treatment has happened under standard conditions or under neuroleptanalgesia treatment in 53 children, 22 children were referred to Faculty Children Hospital. The remaining 31 children received treatment under general anaesthesia in our clinic, after unsuccessful attempts with other treatment options. Five children did not report to the treatment under GA. Based on their systemic conditions, these uncooperative children were divided into three groups: dental anxiety (DA), serious systemic conditions (SD) and other disabilities (OD). The following dental indicators were recorded: caries experience (dmft/DMFT) and restorative index (ri/RI). In addition, types of dental offices that referred children for treatment under general anaesthesia were recorded. The data were processed using descriptive statistics (Fisher exact test). Results: The mean age of all patients was 3.73 years, dmft = 5.55, out of which dt component = 5 = 5.23, mt = 0.19 and ft = 0.13, ri = 2.3%; DMFT = 0.19, out of which DT component = 0.19, MT+FT = 0.0 and RI = 0.0%; no significant differences among boys and girls were found. DA children - dmft = 5.29, dt = 4.9, mt = 0.29, ft = 0.1, ri = 2.38%. SD children - mean age 3.61, dmft = 7.57, dt = 7.29, mt = 0.0, ft = 0.29, ri = 3.17%. OD children - mean age 3.42, dmft =2.0, dt = 2.67, mt+ft = 0.0, ri = 0.0%. Statistically significant differences were only found between DA and SD group in the mean dmft values (p = 0.013) and mean dt values (0.009). Conclusion: The results of this study demonstrate that many uncooperative children can be successfully treated in standard dental office. In children treated under general anaesthesia, SD patients showed significantly higher mean dmft and lower ri than those with dental anxiety. In both groups, unfavourable dental indicators imply insufficient oral hygiene, but also poor dental attendance and inadequate follow-up.

Buddula Aravind

Localized gingival enlargement is often associated with specific systemic medication, abscess formation, trauma or reactive lesions. Scant literature is available reporting enlargement of gingiva due the metastasis of adenocarcinoma from lung. The case report presents a unique case of an adenocarcinoma in the lung metastasizing to the buccal and lingual interdental papillae of teeth numbering 34 and 35. A 72-year-old female was referred to the Mayo Clinic with a recent diagnosis of metastatic stage IV adenocarcinoma of the left lung presented with an abnormal mass located on the left posterior buccal keratinized tissue adjacent to teeth numbering 34-35. Biopsy of the lesion was performed for CK7, CK20, TTF-1 and p63. The tumor cells were positive for CK7 and TTF-1, and weakly positive for p63 suggesting a diagnosis of adenocarcinoma. The periodontist may be in the unique position to be the first oral health care provider to evaluate any biopsy suspicious intra-oral lesions.