Experimental Studies of Fluidized Bed Calcination of Granulated Clay Material.

The work presents a detailed analysis of the possibilities of the thermal processing of clay raw material granulates in a fluidized bed reactor powered by coal fuel. Potential customers of calcined granulates include the following: plants producing refractory materials for the steel industry, producers of refractory concrete, sanitaryware plants, tile plants, large-size tile plants, industry abrasives, chemicals, paints, paper, food and medical industries and others. The advantage of the presented fluid bed calcination technology is the possibility of the continuous operation of the reactor and the short time of the material in the bed, compared to the previously used methods of calcination in a shaft and rotary kiln, which lasts less than twenty minutes in the temperature range of 650-850 °C. During the experimental studies of calcination in the fluidized bed layer, the influence of the type of coal, its particle size and the mass share of coal in the feed mixture on the calcination process and the final product obtained was analysed. As a result of the conducted research, it was proven that solid fuels such as anthracite and steam coal type 31.2 (flaming) can be successfully used in the fluidized bed calcination process of clay materials. The key parameter determining the fluidized bed calcination process is the fuel particle distribution.

What is the safest method of orthodontic debonding - a systematic review of the literature.

The objective of this study was to review the current knowledge based on in vitro and in vivo studies, that evaluated the enamel damage connected with removal of metal and ceramic orthodontic brackets taking into account different debonding methods. Brackets fracture was also assessed. The protocol for this study was constructed according to the PRISMA statement. The literature review was performed in MEDLINE via PubMed, Cochrane and Scopus databases in May 2021. The searching was repeated in Journal of Stomatology, Orthodontic Forum and grey literature was screened using Google Scholar. Out of eligible studies 207 were screened by title and abstract, 85 subjected to full-text analysis and 30 were qualified for the research. The prevalence of enamel fracture ranged from 0 to 94.4%. The results of our review do not allow to identify the manual method of debonding that minimizes the risk of enamel damage. Thermal method and laser irradiation reduce the risk of enamel fracture.

Calcination of Clay Raw Materials in a Fluidized Bed.

Clay raw materials are diverse in terms of their mineral composition, as well as the content of colouring oxides and their physical properties. Determining the suitability of raw materials for various purposes requires comprehensive studies on their properties, as well as their appropriate correction, which is possible through the use of appropriate modification techniques. One of the most commonly used technologies for the enrichment of clay raw materials is to subject them to high temperatures, which, depending on the temperature regime used in the technological process, may cause the decomposition and removal of some addditional components (e.g., carbonates), as well as the removal of water and dehydroxylation of clay minerals, reversible structural changes, and the complete and permanent reconstruction of the mineral phases. This paper presents a new application for fluidization technology in the calcination of clay raw materials. The results of the experiment show that the fluidization method is competitive compared to the technologies that have been used so far, as a result of, inter alia, the much shorter time period required to carry out the calcination process and, consequently, the much lower energy expenditure, the high efficiency of burning coal, and the lower CO2 emissions resulting from the mixing taking place in the reactor.

Causal association between periodontitis and hypertension: evidence from Mendelian randomization and a randomized controlled trial of non-surgical periodontal therapy.

AIMS: Inflammation is an important driver of hypertension. Periodontitis is a chronic inflammatory disease, which could provide a mechanism for pro-hypertensive immune activation, but evidence of a causal relationship in humans is scarce. We aimed to investigate the nature of the association between periodontitis and hypertension. METHODS AND RESULTS: We performed a two-sample Mendelian randomization analysis in the ∼750 000 UK-Biobank/International Consortium of Blood Pressure-Genome-Wide Association Studies participants using single nucleotide polymorphisms (SNPs) in SIGLEC5, DEFA1A3, MTND1P5, and LOC107984137 loci GWAS-linked to periodontitis, to ascertain their effect on blood pressure (BP) estimates. This demonstrated a significant relationship between periodontitis-linked SNPs and BP phenotypes. We then performed a randomized intervention trial on the effects of treatment of periodontitis on BP. One hundred and one hypertensive patients with moderate/severe periodontitis were randomized to intensive periodontal treatment (IPT; sub- and supragingival scaling/chlorhexidine; n = 50) or control periodontal treatment (CPT; supragingival scaling; n = 51) with mean ambulatory 24-h (ABPM) systolic BP (SBP) as primary outcome. Intensive periodontal treatment improved periodontal status at 2 months, compared to CPT. This was accompanied by a substantial reduction in mean SBP in IPT compared to the CPT (mean difference of -11.1 mmHg; 95% CI 6.5-15.8; P < 0.001). Systolic BP reduction was correlated to periodontal status improvement. Diastolic BP and endothelial function (flow-mediated dilatation) were also improved by IPT. These cardiovascular changes were accompanied by reductions in circulating IFN-γ and IL-6 as well as activated (CD38+) and immunosenescent (CD57+CD28null) CD8+T cells, previously implicated in hypertension. CONCLUSION: A causal relationship between periodontitis and BP was observed providing proof of concept for development of clinical trial in a large cohort of hypertensive patients. ClinicalTrials.gov: NCT02131922.

Quantitation of condylar position in temporomandibular joint. A methodological study.

Ten CBCT scans of asymptomatic patients were evaluated on sagittal slices to obtain condylar position in temporomandibular joint. Measurements focused on antero-posterior and superior-inferior position of the condyle. The study the study was performed to investigate reproducibility of the method described before using Dahlberg formula. The method seems to be fair reproducible.

Syndrome of canal of Guyon - definition, diagnosis, treatment and complication.

Syndrome of canal of Guyon is the second after carpal tunnel syndrome, compression syndrome in the wrist. Opposite to median nerve compression, ulnar nerve compression is not very popular. However it impairs functioning of the hand even more than median nerve lesion. Authors deal with definition, possible diagnostic methods, treatment and most frequent complication.

Main health-related quality-of-life issues in patients after a distal radius fracture.

AIM: The aim of this study was to identify and assess the degree and clinical course of the main health-related quality-of-life (HRQoL) issues in patients after a distal radius fracture (DRF). MATERIALS AND METHODS: Patients were eligible if they were between 18-80 years and were within 1-3 days after a non-comminuted DRF. All patients filled out the Polish version of the IOF QLQ, the SF-36 and a demographic questionnaire. Assessment points were set as soon as possible after the fracture, 7 days, 6 weeks, 3 months, and 6 after the fracture. Standard statistical analyses were performed. RESULTS: During the 16 month recruitment period a total of 71 patients (55 women - 77.5%), with a mean age of 64.1 ± 12.4 years, were included in the study group. All patients suffered from Colles type fractures. Attrition to follow-up was acceptable. At baseline, basing on the IOF QLQ scale scores, DRF patients had the most significant problems with physical function (82.8/100; with 100 representing the worst possible HRQoL), and general health (78.1/100). Basing on SF-36 scale scores patients most significant problems were associated with role limitations due to physical health problems (15.1/100; with 100 representing the best possible HRQoL), and bodily pain (39.5/100). CONCLUSIONS: Concluding, this study shows that the main issues with which patients with and extra-articular DRF struggle the most are pain of the fractured extremity and physical dysfunction. These symptoms are most pronounced in the early post-injury period, and in the majority of patients steadily decrease over a period of six months.

Preliminary validation of the IOF QLQ and comparison with the SF-36 in patients after a distal radius fracture.

AIM: The aim of this study was to report preliminary validation data on the Polish version of the International Osteoporosis Foundation Quality of Life Questionnaire (IOF QLQ) for patients with a distal radius fracture (DRF). MATERIALS AND METHODS: Patients were eligible if they were between 18-80 years and were within 1-3 days after a non-comminuted DRF. All patients filled out the Polish version of the IOF QLQ, the Short Form 36 (SF-36) and a demographic questionnaire. Assessment points were set as soon as possible after the fracture, 7 days, 6 weeks, and 3 months after the fracture. Standard va- lidity and reliability analyses were performed. RESULTS: Fifty-eight patients (42 women - 72.4%) agreed to take part in the study (mean age of the group 65.7 ± 9.3 years). Cronbach's alpha coefficients showed positive internal consistency (0.82- 0.87). The interclass correlations for the IOF QLQ domains and the overall score ranged from 0.82 to 0.93. Satisfactory convergent and discriminant validity of the IOF QLQ was seen. CONCLUSIONS: Preliminary data show that the Polish version of the IOF QLQ for patients with a DRF is a reliable and valid tool for measuring health-related quality-of-life (HRQoL). However, further studies are needed to demonstrate the full psychometric and clinical properties of the IOF QLQ in patients with a fracture of the wrist.

Topography of ulnar nerve and its variations with special respect to carpal region.

Ulnar nerve supplies small muscles of the hand and apart from the median nerve is the main coordinator of precise movements performed both in the medical and dental practice. Based on their anatomical and clinical experience, authors revised a knowledge on this nerve with special respect to its topography, variation in the wrist.

Mandible - clinically revisited.

Based on the current literature authors revised anatomical and clinical datas considering the mandible.

Controversies on the position of the mandibular foramen - review of the literature.

Foramen of mandible is the most important point considering the Halsted anesthesia. Position of this foramen seems to be stable, however there are lots of controversies regarded to its position. Based on the current literature authors revised datas from literature considering the location of the mandibular foramen.