Indentation size effect in Knoop and Vickers hardness measurement of dental resin-based composites.

Objectives: Comparisons of material hardness may be affected by the indentation size effect (ISE), which is characterized by increasing hardness values at decreasing loads. This study aimed to assess the influence of load, dwell time and measurement method on ISE in dental resin-based composites with different filler content.

Methods: Knoop (HK) and Vickers (HV) microindentation hardness of Filtek Ultimate Universal Restorative (FU) and Filtek Supreme Flowable Restorative (FF) was measured under different loads (0.

Are there Risks from Nanocomposite Restoration Grinding for Dentists?

Objectives: To evaluate the effect of short-term inhalational exposure to nanoparticles released during dental composite grinding on oxidative stress and antioxidant capacity markers.

Materials And Methods: Twenty-four healthy volunteers were examined before and after exposure in dental workshop. They spent 76.

Transcriptome changes in humans acutely exposed to nanoparticles during grinding of dental nanocomposites.

Today, there is a lack of research studies concerning human acute exposure to nanoparticles (NPs). Our investigation aimed to simulate real-world acute inhalation exposure to NPs released during work with dental nanocomposites in a dental office or technician laboratory. Blood samples from female volunteers were processed before and after inhalation exposure.

Genetic alteration profiling in middle-aged women acutely exposed during the mechanical processing of dental nanocomposites.

Nanoparticles (NPs) have become an important part of everyday life, including their application in dentistry. Aside from their undoubted benefits, questions regarding their risk to human health, and/or genome have arisen. However, studies concerning cytogenetic effects are completely absent.

Elevated glutathione in researchers exposed to engineered nanoparticles due to potential adaptation to oxidative stress.

To find a practical biomonitoring method for researchers exposed to nanoparticles causing oxidative stress. In a continuation of a study in 2016-2018, biological samples (plasma, urine and exhaled breath condensate [EBC]) were collected in 2019-2020 from 43 researchers (13.8 ± 3.

Dental fear/anxiety in Czech preschoolers: relationship to gender, age, location of residence, dental status and previous treatment experience.

Aim: Dental fear/anxiety (DFA) may considerably complicate treatment in paediatric dentistry. This cross-sectional study aimed to assess DFA in Czech preschoolers aged 3-6 years and its relationship to gender, age, location of residence, dental status and previous treatment.

Methods: The study involved 460 children from preschools in four location types selected according to the WHO criteria for oral health surveys.

Bisphenol A Release from Dental Composites and Resin-Modified Glass Ionomers under Two Polymerization Conditions.

Bisphenol A (BPA)-based monomers are commonly contained in dental resin-based materials. As BPA is an endocrine disruptor, its long-term release from restorative composites and resin-modified glass ionomers (RM-GICs) under two polymerization conditions was measured in this study. Specimens of two conventional composites containing BPA-based monomers, two "BPA-free" composites, and two RM-GICs were polymerized from one side for 20 s at 1300 mW/cm or for 5 s at 3000 mW/cm.

Release of Bisphenol A from Milled and 3D-Printed Dental Polycarbonate Materials.

Polycarbonates are polymers of bisphenol A (BPA), a well-known endocrine disruptor. This study evaluated the release of BPA from polycarbonate crowns that were (1) milled from Temp Premium Flexible (ZPF, Zirkonzahn, Italy) or Tizian Blank Polycarbonate (TBP, Schütz Dental, Germany), or (2) 3D-printed (Makrolon 2805, Covestro, Germany). Commercial prefabricated polycarbonate crowns (3M, USA) and milled poly(methyl methacrylate) (PMMA) crowns (Temp Basic, Zirkonzahn, Italy) were included for comparison.

Applicability of Exposure Reciprocity Law for Fast Polymerization of Restorative Composites Containing Various Photoinitiating Systems.

Objectives: The exposure reciprocity law (ERL) has been used to calculate the optimal irradiation time of dental composites. This study examined the applicability of ERL for fast polymerization of restorative composites containing various photoinitiating systems using a high-power multi-peak light-emitting diode (LED) lamp.

Methods: Three commercial composites differing in photoinitiating systems were tested: Filtek Ultimate Universal Restorative (FU) with a camphorquinone-amine (CQ-A) photoinitiating system, Tetric EvoCeram (TEC) with CQ-A and (2,4,6-trimethylbenzoyl)phosphine oxide (TPO), and Estelite Σ Quick (ESQ) with CQ and a radical amplified photopolymerization (RAP) initiator.

Influence of central and peripheral dentin on micro-tensile bond strength estimated using a competing risk model.

The bonding performance of dental adhesives is most frequently evaluated using the micro-tensile bond strength (μTBS) test. Despite lacking evidence, peripheral specimens are often discarded to avoid regional variability. This study, therefore, examined whether μTBS to central and peripheral dentin differed.

Dental composites - a low-dose source of bisphenol A?

Dental composite materials often contain monomers with bisphenol A (BPA) structure in their molecules, e.g. bisphenol-A glycidyl dimethacrylate (Bis-GMA).

A competing risk model for bond strength data analysis.

Objectives: A competing risk (CR) model distinguishing adhesive, cohesive and mixed failures as competing events was used for the analysis of micro-tensile bond strength (μTBS) data and compared with a conventional failure mode non-distinguishing survival model.

Methods: Fifty human molars were bonded using five universal adhesives (n = 10) and subdivided according to aging conditions (24-h water storage, thermocycling). After μTBS to dentin was tested, a fractographic analysis was performed using scanning electron microscopy.

The Effect of Censoring on the Statistical Evaluation of Composite-to-Composite Bond Strength.

Purpose: To determine the effect of Weibull analysis with censoring of cohesive failures on the evaluation of the effect of surface treatment and adhesive on the microtensile composite-composite bond strength.

Materials And Methods: Surfaces of Filtek Z250 (3M Oral Care) specimens aged in distilled water for five months at 37°C were ground with SiC paper P320 or air abraded with Al2O3 and built up with the same composite using Optibond FL (OPF, Kerr), Clearfil SE Bond (CSE, Kuraray Noritake) and Gluma Comfort Bond (GLU, Kulzer) adhesives. After sectioning and trimming, the specimens were stored at 37°C in distilled water for 24 h and then tested in a microtensile bond strength setup.

The effect of disinfectants on the accuracy, quality and surface structure of impression materials and gypsum casts: A comparative study using light microscopy, scanning electron microscopy and micro computed tomography.

The aim of this study was to compare the effect of several commercially available disinfectants on the accuracy of various types of impression materials and their compatibility with gypsum including surface quality and structure evaluation. Four alginate and three elastomeric impression materials in combination with disinfectants Aseptoprint Liquid, Zeta 7 solution, Silosept and Dentaclean Form were tested. The dimensional changes, detail reproduction, the compatibility with gypsum and surface/subsurface morphology were evaluated using light microscopy, scanning electron microscopy and micro computed tomography.

Subsequent application of bonding agents to a one-step self-etch adhesive - Its effect with/without previous light-curing.

Objective: The influence of light-curing of a one-step self-etch adhesive (1-SEA) prior to the application of different bonding agents (BA) on the micro-tensile bond strength (μTBS) to dentin after 24h and thermal cycling was investigated. Additionally, the degree of conversion was evaluated using Fourier-transform infrared spectroscopy.

Methods: Three ion-releasing BAs, BZF-21 (experimental BA), Clearfil SE Protect (CSP), and FL-Bond II (FL-II), were applied subsequently to G-Premio Bond (1-SEA, GPB).

[Diffuse alveolar hemorrhage - acute, life-threatening situation in rheumatology].

Diffuse alveolar hemorrhage (DAH) is a life-threatening acute manifestation of systemic diseases, the most commonly of systemic vasculitis. Clinically DAH manifests by a rapidly progressive respiratory and renal failure. The decisive for diagnose is immediate bronchoscopic examination with the bronchoalveolar lavage examination.

The plausible association of MTHFR and ADORA2A polymorphisms with nodules in rheumatoid arthritis patients treated with methotrexate.

Objective: The treatment of rheumatoid arthritis (RA) patients with methotrexate (MTX) is linked to the development or progression of rheumatoid nodules. The aim of this study was to determine whether folate and adenosine pathways-related single nucleotide polymorphisms might be predictive of increased nodule formation in RA patients treated with oral MTX.

Methods: A total of 185 Caucasian RA patients were enrolled in this cross-sectional study, all of whom fulfilled the 1987 RA criteria of the American College of Rheumatology; each patient had a history of MTX treatment.

Wireless Capsule Enteroscopy in Healthy Volunteers.

Introduction: The aim of our prospective study was to define endoscopy appearance of the small bowel in healthy volunteers.

Method: Forty-two healthy volunteers underwent wireless capsule endoscopy, clinical investigation, laboratory tests, and completed a health-status questionnaire. All subjects were available for a 36-month clinical follow-up.

Methotrexate impact on radiographic progression in biologic-treated rheumatoid arthritis under clinical remission: A case report on monozygotic Caucasian twins.

We describe Caucasian monozygotic twin brothers with rheumatoid arthritis (RA) and discuss influence of predictors to methotrexate (MTX) outcome treatment. Single nucleotide polymorphisms (SNPs) of the MTX metabolic pathways were genotyped. Twins have multiple mutations: a CC mutation of SNP 1298A>C in methylenetetrahydrofolate reductase (MTHFR) gene, CC mutations of three SNPs in the adenosine receptor gene ADORA2A (rs3761422_4217241T>C, rs2267076_4221164T>C, rs2236624_4226593T>C), and a heterozygous genotype in SNPs ATIC_rs2372536_347C>G, MTHFD1_rs2236225_1958G>A.

Small intestinal injury in NSAID users suffering from rheumatoid arthritis or osteoarthritis.

Unlabelled: The goal of this prospective study was to assess non-steroidal anti-inflammatory drug (NSAID)-induced enteropathy in patients with rheumatoid arthritis (RA) or osteoarthritis (OA) by means of non-invasive wireless capsule enteroscopy. A total of 143 patients (74 with RA, 69 with OA) treated with NSAIDs (>1 month) and 42 healthy volunteers were included. All subjects underwent capsule endoscopy, laboratory tests and filled in questionnaires.

Formation of protective deposits by anti-erosive toothpastes-A microscopic study on enamel with artificial defects.

This study investigated formation of protective deposits on the enamel surface after application of several anti-erosive toothpastes with different active ingredients. NaF-containing Sensodyne Pronamel, SnCl /F-based Elmex Erosion Protection and calcium phosphate-based BioRepair Plus Sensitivity Control, SensiShield and Enamel Care toothpastes with claimed anti-erosive properties were tested. Artificial saliva and Elmex Erosion Protection mouth rinse served as control groups.

Application of the DETECT algorithm for detection of risk of pulmonary arterial hypertension in systemic sclerosis: data from a Czech tertiary centre.

Objective: The early, simple and reliable detection of pulmonary arterial hypertension (PAH) in SSc (DETECT) study described a new algorithm for early detection of PAH in patients with SSc. The aim of this retrospective, single-centre, cross-sectional study was to apply a modified DETECT calculator in patients with SSc in the East Bohemian region, Czech Republic, to assess the risk of PAH and to compare these results with PAH screening based on the European Society of Cardiology/European Respiratory Society (ESC/ERS) 2009 guidelines.

Methods: Sixty patients were recruited with a diagnosis of SSc (according to ACR criteria), aged 27-78 years.

The impact of C677T and A1298C MTHFR polymorphisms on methotrexate therapeutic response in East Bohemian region rheumatoid arthritis patients.

Some single-nucleotide polymorphisms (SNPs) might be predictive of methotrexate (MTX) therapeutic outcome in rheumatoid arthritis (RA). The aim of this study was to determine whether SNPs in the methylenetetrahydrofolate reductase (MTHFR) gene are predictive of MTX response. Comparison was made using EULAR response criteria and according to the change of DAS28 (∆DAS28) after a 6-month MTX treatment in RA patient cohort.