Unlocking the potential: laser surface modifications for titanium dental implants.

The review critically evaluates the current state of studies investigating laser irradiation for modifying titanium surfaces to enhance the biointegration of dental implants. Laser modification is a rapidly evolving physicochemical surface modification process with the potential to revolutionize dental implant technology. A thorough search of electronic databases, including PubMed, Science Direct, MEDLINE, and Web of Knowledge, was conducted to identify relevant articles. The review focuses on the surface features of laser-modified implants, encompassing in vitro cell culture experiments, rare animal experiments, and limited clinical trials. Of the 26 selected sources, 21 describe surface features, while only two involve in vivo human experiments. The review highlights the lack of long-term clinical experience and calls for further research to mature these technologies. Despite the absence of a consensus on optimal laser types and settings, the overall results are promising, with few negative outcomes. As research in laser irradiation of titanium surfaces progresses, significant advancements in dental implant technology and improved patient well-being are anticipated.

Applicability of Fractal Analysis for Quantitative Evaluation of Midpalatal Suture Maturation.

BACKGROUND: The treatment of transversal maxillary deficiency usually aims at skeletal expansion. The treatment option highly depends on the maturation stage of the midpalatal suture (MPS), which may vary between individuals at the same chronological age. Therefore, the individual determination of the MPS maturation is crucial. AIMS: Our aim was to investigate the applicability of fractal analysis for the quantitative evaluation of MPS maturation. METHODS: Nine experienced orthodontists were asked to evaluate the MPS maturation on 51 cone beam computed tomography (CBCT) scans according to the Angelieri classification method. Intra- and inter-examiner reliability was measured using Cohen's Kappa coefficient. The stages were agreed upon according to the results of the examiners with the highest strength of agreement. Fractal analysis was then performed on the CBCTs and the correlation between the fractal dimension values and maturation stages was then evaluated. Optimal fractal dimension cut-off values were determined using a receiver operating characteristic curve. RESULTS: The cut-off point was found at 1.073, at which the use of fractal dimension for predicting MPS maturation showed 100% sensitivity, 93.7% specificity, 9.5% false positive, 0% false negative rate. CONCLUSION: Our results provided further evidence that fractal analysis is a reliable tool to determine MPS maturation stage.

Energy drinks alter the surface morphology and roughness of composites, fissure sealants and titanium: An in vitro study.

Objectives: The influence of energy drinks on dental materials are relatively under addressed. Our aim was to investigate the effect of energy drinks on dental materials used intraorally in young individuals. Commonly used preventive, restorative, and orthodontic materials were tested in vitro. Methods: The effect of two commercially available energy drinks (HELL, BURN) was investigated on different dental materials: machined, anodized Titanium (grade 5: Ti6Al4V) and composites (Grandio Seal, VOCO; Filtek Z250, 3M ESPE; Estelite SQ, TOKUYAMA). The roughness (Ra) and morphological changes were examined by atomic force microscopy (AFM) and scanning electron microscopy (SEM). Results: AFM and SEM revealed significant differences in the Ra and morphology of the samples. AFM results for the machined and anodized titanium samples showed that the two energy drinks modified the surface roughness differently; BURN changed the roughness of machined samples significantly, while anodized discs were not altered significantly by the two energy drinks. In case of composite samples there was no significant difference for the Estelite SQ, relative low differences for the Filtek Z250 and significant changes in the morphology and surface roughness of Grandio Seal. Significance: On all tested materials, changes in the surface roughness and morphology were more or less detected, proving energy drinks do in fact have a harmful effect. It can be concluded that material erosion depends on the material composition and particle arrangement. Where the surface is characterized by a regular, uniform particle arrangement, energy drinks are less able to influence the roughness, while for samples where the surface is rich in aggregates, the material erodes the surface much more easily.

[Applicability of the Moyers mixed dentition analysis for the Hungarian population]. / A Moyers-féle vegyes fogazati analízis alkalmazhatóságának vizsgálata a magyarországi lakosság körében.

Introduction: Moyers mixed dentition analysis is one of the most commonly used prediction methods to estimate the size of the unerupted teeth. By its use, we can determine the severity of tooth size-arch length discrepancies in mixed dentition. Since the tooth size may vary considerably among different ethnic groups, for the most precise estimation of the required space, an analysis based on the individual's own ethnic group would be recommended. Aim: Our aim was to evaluate the applicability of Moyers mixed dentition analysis for the Hungarian population. Method: Upper and lower study casts of 370 patients were evaluated. The mesiodistal widths of the teeth were measured by using a Pittsburgh digital caliper. The odontometric values obtained were used to calculate actual and predicted values. The actual teeth measurements were then statistically compared to the predicted values derived from Moyers probability tables. Results: Using Moyers analysis, we found significant differences at each percentile between the actual and predictive values in both sexes. In the upper jaw, values for men at the 95th, 85th, 75th, and 65th percentile overestimated the actual values, while for women only the 65th percentile underestimated it. In the lower jaw, all values were overestimated in relation to the actual measurements at all percentiles. Conclusions: Based on our results, Moyers mixed dentition analysis cannot be reliably applied for the Hungarian population. If used, it is recommended to use the Moyers predicted values at the 65th instead of the 75th percentile, as this will result in closer estimation to the actual space requirements. Orv Hetil. 2019; 160(50): 1984-1989.

Hyperglycemia-Induced Aberrant Cell Proliferation; A Metabolic Challenge Mediated by Protein O-GlcNAc Modification.

Chronic hyperglycemia has been associated with an increased prevalence of pathological conditions including cardiovascular disease, cancer, or various disorders of the immune system. In some cases, these associations may be traced back to a common underlying cause, but more often, hyperglycemia and the disturbance in metabolic balance directly facilitate pathological changes in the regular cellular functions. One such cellular function crucial for every living organism is cell cycle regulation/mitotic activity. Although metabolic challenges have long been recognized to influence cell proliferation, the direct impact of diabetes on cell cycle regulatory elements is a relatively uncharted territory. Among other "nutrient sensing" mechanisms, protein O-linked ß-N-acetylglucosamine (O-GlcNAc) modification emerged in recent years as a major contributor to the deleterious effects of hyperglycemia. An increasing amount of evidence suggest that O-GlcNAc may significantly influence the cell cycle and cellular proliferation. In our present review, we summarize the current data available on the direct impact of metabolic changes caused by hyperglycemia in pathological conditions associated with cell cycle disorders. We also review published experimental evidence supporting the hypothesis that O-GlcNAc modification may be one of the missing links between metabolic regulation and cellular proliferation.

Mechanical stress alters protein O-GlcNAc in human periodontal ligament cells.

Protein O-linked N-acetylglucosamine (O-GlcNAc) is a post-translational modification of intracellular proteins that regulates several physiological and pathophysiological process, including response to various stressors. However, O-GlcNAc's response to mechanical stress has not been investigated yet. As human periodontal ligament (PDL) cells are stimulated by compression force during orthodontic tooth movement that results in structural remodelling, in this study we investigated whether mechanical stress induces any alteration in protein O-GlcNAc in PDL cells. In this study, PDL cells isolated from premolars extracted for orthodontic indications were exposed to 0, 1.5, 3, 7 and 14 g/cm2 compression forces for 12 hours. Cell viability was measured by flow cytometry, and protein O-GlcNAc was analysed by Western blot. Cellular structure and intracellular distribution of O-GlcNAc was studied by immunofluorescence microscopy. We found that between 1.5 and 3 g/cm2 mechanical compression, O-GlcNAc significantly elevated; however, at higher forces O-GlcNAc level was not increased. We also found that intracellular localization of O-GlcNAc proteins became more centralized under 2 g/cm2 compression force. Our results suggest that structural changes stimulated by compression forces have a significant effect on the regulation of O-GlcNAc; thus, it might play a role in the mechanical stress adaptation of PDL cells.

[Classical and modern methods for the assessment of skeletal maturation and pubertal growth spurt]. / Klasszikus és modern vizsgálómódszerek a csontérettségi kor és a pubertáskori növekedési csúcs meghatározására.

The assessment of skeletal age is of utmost importance not only in the field of anthropology, forensic medicine, pediatrics, endocrinology but also in orthodontics and jaw orthopedics. Bone age refers to the individual's biological development which can differ within a relatively wide range for the same chronological age. Therefore, accurate assessment of skeletal maturity and pubertal growth plays an important role in establishing a diagnosis for certain diseases. In addition, it is essential for proper timing and success of treatments in many cases. Currently, there are many methods available to determine skeletal age and pubertal growth spurt. During growth, bones undergo significant changes, the sequence of which is strongly determined. These changes can be measured by various methods including radiological examinations. More specifically, these classical methods are often based on the radiological evaluation of morphological changes in the hand bones and cervical vertebrae. Methods based on dental development also exist to assess the biologic maturity of an individual. However, thanks to three-dimensional imaging techniques and molecular diagnostic methods, even more accurate tests can be performed to determine biological maturity. These modern methods rely on the information obtained from the cone-beam computer tomograph records and on the measurements of biomarkers present in different circulatory or other body fluids. The purpose of this summary is to provide an overview of the various classical and modern methods for the assessment of skeletal age that could aid us in many fields of science. Orv Hetil. 2018; 159(35): 1423-1432.

Comparison of the effect of premolar extraction and non-extraction on the position and developmental changes of the lower third molars.

The aim of the present study was to comprehensively assess the posttreatment effect of premolar extraction versus non-extraction on the position and development of the lower third molars. The sample consisted of 227 patient's pre- and posttreatment panoramic radiographs (53 with four premolar extractions, 174 without extractions). The position and developmental stage of the lower third molars were evaluated by using Pell-Gregory's, Winter's, modified Miloro-DaBell's and Demirjian's classifications, respectively. Premolar extraction had a considerably positive influence on the position and development of the lower third molars and therefore could provide better prognosis for their eruption.

Lithium induces ER stress and N-glycan modification in galactose-grown Jurkat cells.

We previously reported that lithium had a significant impact on Ca(2+) regulation and induced unfolded protein response (UPR) in yeast cells grown on galactose due to inhibition of phosphoglucomutase (PGM), however the exact mechanism has not been established yet. In this study, we analysed lithium's effect in galactose-fed cells to clarify whether these ER-related changes are the result of a relative hypoglycemic state. Furthermore, we investigated whether the alterations in galactose metabolism impact protein post-translational modifications. Thus, Jurkat cells were incubated in glucose or galactose containing media with or without lithium treatment. We found that galactose-fed and lithium treated cells showed better survivability than fasting cells. We also found higher UDP-Hexose and glycogen levels in these cells compared to fasting cells. On the other hand, the UPR (X-box binding protein 1 mRNA levels) of galactose-fed and lithium treated cells was even greater than in fasting cells. We also found increased amount of proteins that contained N-linked N-acetyl-glucosamine, similar to what was reported in fasting cells by a recent study. Our results demonstrate that lithium treatment of galactose-fed cells can induce stress responses similar to hypoglycemia, however cell survival is still secured by alternative pathways. We propose that clarifying this process might be an important addition toward the better understanding of the molecular mechanisms that regulate ER-associated stress response.

Polymethyl-methacrylate-sorbitol-based capsules as local drug delivery vehicles: an in vitro antibiotic elution study.

A PMMA (polymethyl-methacrylate)-sorbitol-based capsule system was recently developed, and the permeability of 16 types of capsules with different wall thicknesses and sorbitol contents tested. By optimizing these two parameters, we showed that capsule permeability could be controlled. Promising preliminary data obtained using BPB (Bromophenol Blue) as diffusion marker prompted us to further investigate the antibiotic release of capsules showing the most appropriate release characteristics. PMMA-sorbitol capsules were prepared with wall thickness of 0.5 or 0.6 mm and 60 or 70 w/w% (weight percent) of sorbitol content. In vitro gentamicin, amikacin, tobramycin releases were determined by using a microbiological agar plate diffusion assay. Capsules released 70-100% of their gentamicin load, substantially superior to Septopal, and showed preferable, extended release profiles when compared with the beads. The release kinetics of amikacin and tobramycin closely resembled those of gentamicin. PMMA-sorbitol capsules have been developed and tested, which make them promising devices for local antibiotic delivery.

Polymethyl-methacrylate-sorbitol-based capsules as local drug delivery vehicles: a preliminary study.

Local delivery of antibiotics via PMMA (polymethyl-methacrylate) has been widely used in the treatment of chronic osteomyelitis for over 40 years. Unfortunately, PMMA is water insoluble, which seriously limits antibiotic delivery. In addition, the polymerization temperature of PMMA is high, and consequently, only heat-stable antibiotics can be used. Therefore our aim has been to develop an effective antibiotic delivery system, which can be loaded with a wide variety of drugs and deliver the molecules in a predictable manner. Capsules with wall thicknesses of 0.3-0.6 mm from PMMA mixtures containing 40-70 w/w% (weight percent) of sorbitol were prepared and their permeability tested with BPB (Bromophenol Blue). Sorbitol content and wall thickness correlated with the BPB release. SEM (scanning electron microscopy) showed that the canalization of capsules also was well correlated with both sorbitol content and wall thickness. The PMMA-sorbitol-based capsule can potentially be a versatile tool in assuring effective delivery of antibiotics and other substances.

O-GlcNAc modification of proteins affects volume regulation in Jurkat cells.

An increasing amount of recent research has demonstrated that the hexosamine biosynthesis pathway (HBP) plays a significant role in the modulation of intracellular signaling transduction pathways, and affects cellular processes via modification of protein by O-linked beta-N-acetylglucosamine (O-GlcNAc). Besides the many known and postulated effects of protein O-GlcNAc modifications, there is little available data on the role of O-GlcNAc in cellular volume regulation. Our objective was to test the effect of increased O-GlcNAc levels on hypotonia-induced volume changes in Jurkat cells. We pretreated Jurkat cells for 1 h with glucosamine (GlcN), PUGNAc (O-(2-acetamido-2-deoxy-D-glucopyranosylidene)-amino-N-phenylcarbamate) an inhibitor of O-GlcNAcase, or a high level of glucose to induce elevated levels of O-GlcNAc. We found that the response of Jurkat cells to hypotonic stress was significantly altered. The hypotonia induced cell-swelling was augmented in both GlcN and PUGNAc-treated cells and, to a lesser extent, in high glucose concentration-treated cells. Evaluated by NMR measurements, GlcN and PUGNAc treatment also significantly reduced intracellular water diffusion. Taken together, increased cell swelling and reduced water diffusion caused by elevated O-GlcNAc show notable analogy to the regulatory volume changes seen by magnetic resonance methods in nervous and other tissues in different pathological states. In conclusion, we demonstrate for the first time that protein O-GlcNAc could modulate cell volume regulation.