Pairwise Comparison Tests Research Articles

Reliability of a face scanner in measuring the vertical dimension of occlusion

ObjectiveThis study evaluated the reliability of a face scanner in measuring the vertical dimension of occlusion (VDO). MethodsFully 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. Results120 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. ConclusionsThe 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 SignificanceFindings 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.

Does gentrification precede and follow greening? Evidence about the green gentrification cycle in Los Angeles and Chicago

The health benefits of green space have led to calls for equitable access to parks. When new green spaces are built in low-income communities, however, gentrification often ensues. The “green gentrification” literature has paid little attention to gentrification that might occur before greening. In this paper, we explore whether and under which circumstances gentrification might precede and follow greening, a process known as the “green gentrification cycle.” Focusing on Los Angeles and Chicago, we build hedonic models focused on single-family homes sold in 2010–2021 and run post-hoc pairwise comparison tests to assess price changes over time for homes within a half-mile of new parks (treatment) and farther (control). When considering all new parks, we find that gentrification is associated with subsequent greening and, to some extent, that greening is associated with ensuing gentrification in Los Angeles. In Chicago, gentrification is associated with subsequent greening, but new parks are not associated with ensuing gentrification. Models distinguishing larger regional from smaller non-regional parks show evidence of gentrification before and after non-regional parks were built in Los Angeles, but not for regional parks. In Los Angeles, we identify stronger evidence of gentrification preceding greening farther from downtown than closer to downtown, and signals of gentrification after greening near downtown but not farther away. Models focusing on new parks built near transit stations show inconclusive results. Despite methodological limitations (e.g., examining a single measure of gentrification and different park types together), our findings shed light on the complex spatiotemporal relationships between greening and gentrification.

Evaluation of open-face maxillary complete denture for patients with prominent premaxilla: a crossover study.

The establishment of good facial esthetics is one of the main objectives of complete denture construction. Unfortunately, it may be the caused issue for patients having a prominent premaxilla due to excessive lip support by the labial flange of the maxillary denture. Open-face dentures (OFD) may suggest suitable prosthetic management for these patients. However, clinical evidence regarding the efficiency of OFD is scarce. A total of 38 completely edentulous participants having prominent premaxilla and skeletal class I Angle's classification were enrolled in this study. Each participant received a mandibular complete denture and 2 opposing maxillary dentures; conventional (CD) and open-face (OFD). On the day of denture insertion, the participants were divided into 2 groups; CD-OFD and OFD-CD where CD-OFD group was instructed to use the mandibular denture and the maxillary CD for 3 months and then to use the maxillary OFD for another 3 months after a wash-out period of 2 weeks. While group OFD-CD was instructed to use the mandibular denture and the maxillary OFD for 3 months then to use the maxillary CD for another 3 months after a wash-out period of 2 weeks. The dislodging force of the maxillary dentures was evaluated using the universal testing machine and the patient perception of retention, esthetics, and comfort was evaluated using the Visual Analogue Scale (VAS). Evaluation was carried out 1 day, 1 month, and 3 months after denture insertion. The Student t-test was used to compare the 2 maxillary dentures and the intervals for each denture were compared by using the ANOVA test with repeated measures followed by a Post Hoc test (adjusted Bonferroni) for pairwise comparison. The significance of the obtained results was judged at the 5% level (P value). The dislodging force and patient perception of retention did not show significant differences between the 2 dentures, while the perception of esthetics showed significant differences throughout the follow-up period. Perception of comfort showed an insignificant difference only at the 3-month interval. Open-face maxillary dentures can be a suitable alternative for patients with prominent premaxilla to achieve satisfactory retention, aesthetics, and comfort.

Effect of laser etching on surface characteristics and porcelain bond to soft milled and direct metal laser sintered cobalt chromium alloys

Statement of problemThe surface topography of metal substrate can affect its bond to porcelain. A neodynium-doped yttrium aluminum garnet (Nd:YAG) laser has been introduced to modify the metal surface topography and improve porcelain bond strength. However, studies on the effect of laser etching on metal to porcelain bond strength are lacking. PurposeThe purpose of this in vitro study was to determine the effect of Nd:YAG laser etching on the surface roughness and wettability of and the porcelain bond strength to cobalt chromium (Co-Cr) substrate fabricated by milling and direct metal laser sintering (DMLS). Material and methodsThirty-two 0.5×3×25-mm Co-Cr specimens were fabricated by milling soft Co-Cr (M group) and DMLS Co-Cr metal powder (DML group). The surface topography of representative specimens from each study group was assessed under a scanning electron microscope (SEM) and an atomic force microscope (AFM). All specimens were assessed for surface roughness using a contact profilometer, and for wettability with a contact angle goniometer. Half of the specimens of each study group (n=8) were subjected to surface laser etching by using a Nd:YAG laser. The specimens subjected to etching were assessed again for surface topography and wettability. All specimens in both study groups were veneered with porcelain. The porcelain bond strength was tested with a 3-point bend test in a universal testing machine. The results were statistically analyzed with 2-way ANOVA test followed by the post hoc Tukey test for pairwise comparisons (α=.05). ResultsAfter etching, the M group had a higher mean ±standard deviation Ra and Rz of 2.9 ±0.6 and 17.7 ±3.2 µm and significantly better wettability and bond strength of 79 ±6 and 52 ±13 MPa. In contrast, after etching, the DMLS group had a significantly lower Ra and Rz of 7.9 ±2.4 and 41.8 ±9.3 µm and significantly lower wettability and bond strength of 87 ±4 and 70 ±10 MPa. The DMLS group had a significantly higher roughness and bond strength than the M group before and after laser etching. The SEM and AFM showed different surface topography in the study groups. ConclusionsThe manufacturing process of Co-Cr substrate had a significant effect on surface characteristics and porcelain bond strength. Laser etching improved the surface topography and bond strength of milled Co-Cr but not of DMLS Co-Cr.

Evaluating the antifungal effectiveness, leaching characteristics, flexural strength, and impact strength of polymethyl methacrylate added with small-scale silver nanoparticles - An in vitro study.

(1) To assess the release of stable silver nanoparticles (AgNPs) of small scale dimension added to heat polymerized polymethyl methacrylate (PMMA) in 6 months. (2) Assessing the influence of incorporating minimal concentrations of stable AgNPs with nanoscale dimensions into heat polymerized PMMA over a 6 month period on its antifungal efficacy (AF), flexural strength (FS), and impact strength (IS). Incorporating nanoparticles with a very small scale may have minimal impact on mechanical properties due to their diminutive size. However, the influence of these small scaled nanoparticles on antimicrobial efficacy and potential escalation in toxicity to host cells through leaching remains unexplored. AgNPs were prepared using an Ultrasonic Probe sonicator and the addition of ammonia to obtain stabilized AgNPs (< 0.01 nm) of small scale dimension. The characterization of these AgNPs involved ultraviolet visible spectroscopy, X ray diffraction, Zetasizer, and transmission electron microscopy with energy dispersive spectroscopy (TEM). The prepared AgNPs were then added in various percentages by weight (0%-0.5%) to fabricate 252 modified PMMA samples of sizes 10 mm × 3 mm (AF, n = 108), 65 mm × 10 mm × 3 mm (FS, n = 72), and 65 mm × 10 mm × 2.5 mm (IS, n = 72) as per ADA specification no. 12. These samples underwent testing for leaching out of AgNPs and efficacy against Candida albicans for 6 months. The effect on FS and IS was evaluated using the three point bending test and Charpy's Impact Tester, respectively. Intergroup comparison of CFU between various concentrations of AgNP was done using the Kruskal-Wallis ANOVA test succeeded by Mann-Whitney test for pair wise comparisons. Difference in CFU of various concentrations over 6 months was seen using one way ANOVA test. Intergroup comparison of FS and IS was performed using a one way ANOVA test, followed by a post hoc Tukey's test for pair wise comparisons. Repeated tests showed no leaching out of AgNPs from the denture base resin into the storage medium. All concentrations of AgNPs incorporated in resin showed inhibition of Candida growth. Intergroup comparison of FS and IS revealed highly statistically significant differences (F = 15.076, P < 0.01 and F = 28.266, P < 0.01) between the groups showing a reduction in strength. The AgNPs of small scale dimension incorporated into the denture base resin imparted a strong antifungal effectiveness against C. albicans, which did not decline during the study period and did not cause any release of nanoparticles. 0.5% showed the best antifungal efficacy. This may prove to be a viable and highly effective treatment for the prevention of Candida associated denture stomatitis. However, the inclusion of these particles resulted in a decrease in both FS and IS, and this reduction was directly proportional to the percentage of added AgNPs, with 0.5% demonstrating the least IS and FS.

Green Synthesis, Characterization, and Evaluation of the Antimicrobial Properties and Compressive Strength of Hydroxyapatite Nanoparticle-Incorporated Glass Ionomer Cement.

Background Glass ionomer cement (GIC) plays a vital role in dental restorative procedures, serving purposes such as filling, luting, and adhesion. However, its inadequate mechanical properties pose challenges, especially in areas experiencing significant stress. To overcome this limitation, nanohydroxyapatite (nHA), known for its bioactive phosphate content, is added to the GIC at specific concentrations to improve its properties. Aim We aim to evaluate the antimicrobial property and compressive strength of green-mediated nHA-incorporated GIC. Material and methods Green synthesis of hydroxyapatite nanoparticles was prepared using Moringa oleifera extract in a solvent form and eggshell waste served as the calcium source. These nHApowders were then integrated into the GICat varying concentrations (3%, 5%, and 10%) designated as Group I, Group II, and Group III, respectively, while Group IV (control) consisted of conventional GIC. Specimens were fabricated and subjected to chemical structure analysis through Fourier transform infrared spectroscopy (FTIR), energy dispersive X-ray (EDX), and scanning electron microscopy (SEM). The antimicrobial activity and compressive strength of all groups were investigated. The antimicrobial activity against Streptococcus mutans and Lactobacillus was evaluated through the minimum inhibitory concentration (MIC) test, while compressive strength was evaluated by measuring the maximum force endured by the specimen before fracturing. Data analysis utilized IBM SPSS Statistics software, employing repeated measures ANOVA to determine mean MIC values and compressive strength, with Tukey's posthoc test for pairwise comparisons. Results The results of the study showed that the antimicrobial efficacy of nHA GIC improved with increasing weight percent (% wt) of the additive, exhibiting significantly enhanced activity against Streptococcus mutans and Lactobacillus compared to the control group (Group IV) with statistical significance (p < 0.05). Moreover, the compressive strength exhibited notable enhancements in the modified groups, including Group I (172.55 ± 0.76), Group II (178.16 ± 0.760), and Group III (182.45 ± 0.950), when compared to the control (162.46 ± 1.606), with statistically significant differences (p < 0.05). Conclusion The study demonstrates that the incorporation of green-mediated nHA-containing GIC results in superior antimicrobial efficacy and compressive strength compared to the control group (Group IV). In particular, the highest concentration of nHA-modified GIC (10%) exhibited the most favorable antimicrobial properties along with increased strength. Therefore, utilizing green-mediated nHA in the GIC shows promise as an effective restorative material. Future investigations should delve into the molecular chemistry and bonding mechanisms to further explore its potential.

Color- and strength-graded zirconia: Strength, light transmission, and composition

Statement of problemNatural teeth are graded in terms of translucency and strength. Graded zirconia materials are now available with a higher yttria content on the top or in the enamel zone to increase surface translucency and a lower yttria content on the bottom or in the dentin zone to increase strength. Such materials could provide multiple advantages over uniform materials and reduce the need for porcelain veneering in anterior artificial crowns; however, studies on the properties of these materials are lacking. PurposeThe purpose of this in vitro study was to measure and compare the biaxial flexural strength, percentage light transmission, elemental content, and phase content of zones within and among color graded zirconia blocks and color- and strength-graded zirconia blocks. Material and methodsDisks of a color graded material (Katana STML) and a strength- and color-graded material (IPS e.max ZirCAD Prime) were fabricated (Zircom Furnace). Biaxial flexural strength was measured using a piston-on-3-ball test in a universal testing machine (n=10). Absolute light transmission was measured with a spectrophotometer. Elemental compositions were quantified for 3 zones in each of the 2 zirconia materials using X-ray fluorescence analysis. Zirconia phase fractions were quantified for 3 zones using X-ray diffraction analysis (XRD). Where appropriate, 2-way ANOVA, 1-way ANOVA, and Tukey multiple pairwise comparison testing were used to determine which of the 6 zones differed from one another (α=.05). ResultsThe color-graded zirconia exhibited gradients in light transmission and differences in phase content in the 3 zones measured. The color- and strength-graded zirconia exhibited gradients in light transmission, biaxial flexural strength, elemental composition, and phase content in the 3 zones measured. The bottom, dentin, or intaglio layer of a strength graded zirconia material was substantially stronger than all other zones of either material (P<.05). The top, enamel, zones of both materials possessed high light transmissibility (P<.05). The 2 materials differed with respect to biaxial strength (P<.001), light transmission (P<.02), elemental composition, and phase composition overall, as well as in most zone-by zone comparisons (P<.05). The performance and composition of the color graded material was consistent with it being a 5Y material throughout. The performance and composition of the color and strength graded material was consistent with it having a 3Y bottom zone and a 5Y top zone. ConclusionsA strength-graded and color-graded zirconia material offers potential advantages in both strength and translucency.

Abstract 5525: Tissue-resident cytotoxic T cell infiltration predicts metachronous colorectal cancer metastasis

Abstract Background: Identifying patients at high risk for metachronous colorectal cancer metastasis is essential for improving prognosis. The balance between host immune regulation and tumor immune evasion ultimately permits or prevents cancer progression. Lymphocytic infiltration in colorectal cancer can predict long-term clinical outcomes. However, these lymphocytes' origin, subtype and function have yet to be adequately explored. We investigated the association between the development of metastasis and CD8+T cells expressing the integrin protein CD103, a marker of tissue-resident memory T cells. Methods: In this retrospective, case-control matched study, we conducted multiplex immunofluorescence staining of tumor samples from 124 patients with colorectal cancer. Tissue microarrays containing representative cores of the central tumor, invasive margin, and adjacent normal tissue were immunostained for CD3, CD8, CD103, pSMAD3, and cytokeratin, using tyramide signal amplification. Cells were quantified using StrataQuest digital image analysis software, with intratumoral and stromal regions analyzed separately. Kruskal-Wallis one-way analysis of variance with subsequent Dunn’s test for pair-wise comparisons was performed using the Bonferroni method of multiple-comparison correction. Results: Central tumor and invasive margin CD3+ densities were associated with synchronous metastasis. Compared to non-metastatic patients, those who went on to develop metachronous metastasis (n=42) had a low proportion of intra-epithelial CD8+CD103+ T cells at the central tumor (non-metastatic: 32.8%, IQR 15.0-42.7%; metachronous metastasis: 12.9%, IQR 2.08-28.4%; P = 0.013). Similarly, patients with metachronous metastasis had a low proportion of stromal CD8+CD103+ T cells at the invasive margin (non-metastatic: 3.51%, IQR 1.83-6.55%; metachronous metastasis: 1.75%, IQR 0.62-3.72%; P = 0.019). On multivariate Cox regression of histological features, amongst patients with metastasis, significant overall survival prognostic markers included a low proportional CD8+CD103+ T cell infiltration (HR 2.41, 95%CI 1.16-5.01, P = 0.019), mucinous features (HR 4.28, 95%CI 1.98-9.24, P &amp;lt; 0.001), and the presence of perineural invasion (HR 2.75, 95%CI 1.28-5.89, P &amp;lt; 0.001). Conclusion: CD8+CD103+ lymphocytes may protect from the development of colorectal metastasis. Proportional CD8+CD103+ T cell infiltration is a promising prognostic marker in colorectal adenocarcinoma for the development of metachronous metastasis, and, amongst patients with metastasis, it is a prognostic marker of overall survival. Citation Format: Ryan Cohen, Tracey Lee-Pullen, Timothy Miller, Shadi Pirasteh, Cameron Platell, Katie Meehan, Kathy Fuller, Melanie McCoy. Tissue-resident cytotoxic T cell infiltration predicts metachronous colorectal cancer metastasis [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 5525.

Influence of visceral manipulation on hormonal profile in women with polycystic ovarian syndrome: A randomized trial

Background. Polycystic ovary syndrome (PCOS) is the most common endocrine condition in women of reproductive age and has been suggested as a risk factor for cardiometabolic disease. Depending on which diagnostic criteria are applied, approximately 10–15% of the women of reproductive age are affected by PCOS.Objective. To examine how viscera manipulation Influences hormonal profile in women with PCO. Design. A prospective randomized single-blind controlled trial. Setting. Outpatient clinics of Sadat General Hospital. Methods. Thirty patients of PCO females were recruited and randomized into two equal groups: the control group received a diet guidelines therapy in the form of the hypocaloric Mediterranean diet for 12 weeks, and the study group received the same control group interventions in addition to visceral manipulation (VM). biochemical analysis (FSH &amp; LH) and BMI was the primary outcome. All variables were measured at the baseline and after 12 weeks of the intervention. Results. Statistical analysis was done by using paired’ test which showed significant improvement in both groups. Therefore, using mixed design MANOVA and multiple pairwise comparison tests (Post hoc tests) for the BMI and LH/FSH ratio post-treatment revealed that there were significant decreases in LH/FSH ratio (p =0.007) in favor to group B when compared with group A, with no significant differences in BMI between both groups (p = 0.443), showing that VM group (B) is more effective than group (A) on biochemical analysis (p &lt; 0.05). Conclusion. Using visceral manipulation with a standard program of hypocaloric Mediterranean diet has more beneficial effects on hormonal profile in women with PCO.

The impact of ovarian stimulation on the human endometrial microenvironment.

How does ovarian stimulation (OS), which is used to mature multiple oocytes for ART procedures, impact the principal cellular compartments and transcriptome of the human endometrium in the periovulatory and mid-secretory phases? During the mid-secretory window of implantation, OS alters the abundance of endometrial immune cells, whereas during the periovulatory period, OS substantially changes the endometrial transcriptome and impacts both endometrial glandular and immune cells. Pregnancies conceived in an OS cycle are at risk of complications reflective of abnormal placentation and placental function. OS can alter endometrial gene expression and immune cell populations. How OS impacts the glandular, stromal, immune, and vascular compartments of the endometrium, in the periovulatory period as compared to the window of implantation, is unknown. This prospective cohort study carried out between 2020 and 2022 included 25 subjects undergoing OS and 25 subjects in natural menstrual cycles. Endometrial biopsies were performed in the proliferative, periovulatory, and mid-secretory phases. Blood samples were processed to determine serum estradiol and progesterone levels. Both the endometrial transcriptome and the principal cellular compartments of the endometrium, including glands, stroma, immune, and vasculature, were evaluated by examining endometrial dating, differential gene expression, protein expression, cell populations, and the three-dimensional structure in endometrial tissue. Mann-Whitney U tests, unpaired t-tests or one-way ANOVA and pairwise multiple comparison tests were used to statistically evaluate differences. In the periovulatory period, OS induced high levels of differential gene expression, glandular-stromal dyssynchrony, and an increase in both glandular epithelial volume and the frequency of endometrial monocytes/macrophages. In the window of implantation during the mid-secretory phase, OS induced changes in endometrial immune cells, with a greater frequency of B cells and a lower frequency of CD4 effector T cells. The data underlying this article have been uploaded to the Genome Expression Omnibus/National Center for Biotechnology Information with accession number GSE220044. A limited number of subjects were included in this study, although the subjects within each group, natural cycle or OS, were homogenous in their clinical characteristics. The number of subjects utilized was sufficient to identify significant differences; however, with a larger number of subjects and additional power, we may detect additional differences. Another limitation of the study is that proliferative phase biopsies were collected in natural cycles, but not in OS cycles. Given that the OS cycle subjects did not have known endometrial factor infertility, and the comparisons involved subjects who had a similar and robust response to stimulation, the findings are generalizable to women with a normal response to OS. OS substantially altered the periovulatory phase endometrium, with fewer transcriptomic and cell type-specific changes in the mid-secretory phase. Our findings show that after OS, the endometrial microenvironment in the window of implantation possesses many more similarities to that of a natural cycle than does the periovulatory endometrium. Further investigation of the immune compartment and the functional significance of this cellular compartment under OS conditions is warranted. Research reported in this publication was supported by the National Institute of Allergy and Infectious Diseases (R01AI148695 to A.M.B. and N.C.D.), Eunice Kennedy Shriver National Institute of Child Health and Human Development (R01HD109152 to R.A.), and the March of Dimes (5-FY20-209 to R.A.). The content is solely the responsibility of the authors and does not necessarily represent the official views of the National Institutes of Health or March of Dimes. All authors declare no conflict of interest.

Evaluating the consistency in different methods for measuring left atrium diameters

BackgroundThe morphological information of the pulmonary vein (PV) and left atrium (LA) is of immense clinical importance for effective atrial fibrillation ablation. The aim of this study is to examine the consistency in different LA diameter measurement techniques.MethodsRetrospective imaging data from 87 patients diagnosed with PV computed tomography angiography were included. The patients consisted of 50 males and 37 females, with an average age of (60.74 ± 8.70) years. Two physicians independently measured the anteroposterior diameter, long diameter, and transverse diameter of the LA using six different methods. Additionally, we recorded the post-processing time of the images. Physician 1 conducted measurements twice with a one-month interval between the measurements to assess intra-rater reliability. Using the intraclass correlation coefficient (ICC), the consistency of each LA diameter measurement by the two physicians was evaluated. We compared the differences in the LA diameter and the time consumed for measurements using different methods. This was done by employing the rank sum test of a randomized block design (Friedman M test) and the q test for pairwise comparisons among multiple relevant samples.Results(1) The consistency of the measured LA diameter by the two physicians was strong or very strong. (2) There were statistical differences in the anteroposterior diameter, long diameter, and transverse diameter of LA assessed using different methods (χ2 = 222.28, 32.74, 293.83, P < 0.001). (3) Different methods for measuring the diameters of LA required different amounts of time (χ2 = 333.10, P < 0.001).ConclusionThe results of left atrium (LA) diameter measurements conducted by different physicians were found to be reliable. However, the LA diameters obtained through various techniques exhibited variations. It was observed that measuring LA long diameters using only the VR (volume rendering) picture was the most clinically applicable method.

Amelogenin-inspired peptide, calcium phosphate solution, fluoride and their synergistic effect on enamel biomimetic remineralization: an in vitro pH-cycling model

BackgroundSeveral methods were introduced for enamel biomimetic remineralization that utilize a biomimetic analogue to interact and absorb bioavailable calcium and phosphate ions and induce crystal nucleation on demineralized enamel. Amelogenin is the most predominant enamel matrix protein that is involved in enamel biomineralization. It plays a major role in developing the enamel’s hierarchical microstructure. Therefore, this study was conducted to evaluate the ability of an amelogenin-inspired peptide to promote the remineralization potential of fluoride and a supersaturated calcium phosphate solution in treating artificially induced enamel carious lesions under pH-cycling regimen.MethodsFifty enamel slices were prepared with a window (4*4 mm2 ) on the surface. Five samples were set as control healthy enamel and 45 samples were subjected to demineralization for 3 days. Another 5 samples were set as control demineralized enamel and 40 enamel samples were assigned into 8 experimental groups (n=5) (P/I, P/II, P/III, P/AS, NP/I, NP/II, NP/III and NP/AS) according to peptide treatment (peptide P or non-peptide NP) and remineralizing solution used (I; calcium phosphate solution, II; calcium phosphate fluoride solution, III; fluoride solution and AS; artificial saliva). Samples were then subjected to demineralization/remineralization cycles for 9 days. Samples in all experimental groups were evaluated using Raman spectroscopy for mineral content recovery percentage, microhardness and nanoindentation as healthy, demineralized enamel and after pH-cycling. Data were statistically analysed using two-way repeated measures Anova followed by Bonferroni-corrected post hoc test for pairwise multiple comparisons between groups. Statistical significance was set at p= 0.05. Additionally, XRD, FESEM and EDXS were used for crystal orientation, surface morphology and elemental analysis after pH-cycling.ResultsNanocrystals clumped in a directional manner were detected in peptide-treated groups. P/II showed the highest significant mean values in mineral content recovery (63.31%), microhardness (268.81±6.52 VHN), elastic modulus (88.74±2.71 GPa), nanohardness (3.08±0.59 GPa) and the best crystal orientation with I002/I300 (1.87±0.08).ConclusionDespite pH changes, the tested peptide was capable of remineralizing enamel with ordered crystals. Moreover, the supplementary use of calcium phosphate fluoride solution with peptide granted an enhancement in enamel mechanical properties after remineralization.

Modified Archimedes optimization algorithm for global optimization problems: a comparative study

Archimedes Optimization Algorithm (AOA) is a recent optimization algorithm inspired by Archimedes’ Principle. In this study, a Modified Archimedes Optimization Algorithm (MDAOA) is proposed. The goal of the modification is to avoid early convergence and improve balance between exploration and exploitation. Modification is implemented by a two phase mechanism: optimizing the candidate positions of objects using the dimension learning-based (DL) strategy and recalculating predetermined five parameters used in the original AOA. DL strategy along with problem specific parameters lead to improvements in the balance between exploration and exploitation. The performance of the proposed MDAOA algorithm is tested on 13 standard benchmark functions, 29 CEC 2017 benchmark functions, optimal placement of electric vehicle charging stations (EVCSs) on the IEEE-33 distribution system, and five real-life engineering problems. In addition, results of the proposed modified algorithm are compared with modern and competitive algorithms such as Honey Badger Algorithm, Sine Cosine Algorithm, Butterfly Optimization Algorithm, Particle Swarm Optimization Butterfly Optimization Algorithm, Golden Jackal Optimization, Whale Optimization Algorithm, Ant Lion Optimizer, Salp Swarm Algorithm, and Atomic Orbital Search. Experimental results suggest that MDAOA outperforms other algorithms in the majority of the cases with consistently low standard deviation values. MDAOA returned best results in all of 13 standard benchmarks, 26 of 29 CEC 2017 benchmarks (89.65%), optimal placement of EVCSs problem and all of five real-life engineering problems. Overall success rate is 45 out of 48 problems (93.75%). Results are statistically analyzed by Friedman test with Wilcoxon rank-sum as post hoc test for pairwise comparisons.

Improving the Nutritional Status of Stunted Children through Providing Additional Fish-Based Food

For toddlers who are stunted, processed fish food can be utilized as an additional source of healthy nutrients. This study set out to assess how supplementing fish-based meals affected the nutritional status of toddlers who were stunted. 37 stunted toddlers in Lubuklinggau City received Additional Fish-Based Food for ninety days, from September to December 2023, as part of the study's sample. This research approach used an experimental design with a pre- and post-test strategy without control. Pairwise comparison tests were employed to do statistical analysis by evaluating the nutritional status of toddlers prior to and following the intervention. The research will be finished by December 2023. 6 (16.21%) of the toddlers had improved to a normal nutritional state, according to the data. The nutritional status of toddlers differed significantly before and after the intervention, as evidenced by a p-value of 0.000 (0.05). Thus, it can be said that giving toddlers extra fish-based meal treatments for ninety days can enhance their nutritional status and lower the incidence of stunting in the toddlers who are the target population.

Comparative Evaluation of Push-out Bond Strength of Three Different Root Canal Sealers: An In Vitro Study.

The aim of this present study was to compare the dislodgement resistance of calcium silicate-based sealer, zinc oxide sealer, and a new sealer combining both zinc oxide and calcium silicate-based sealer in vitro. 60 single-rooted human teeth were instrumented with F3 Protaper Gold. All endodontic canals were filled using gutta percha cones using the cold lateral condensation technique in combination using one of the mentioned sealers (n = 20 per group). The teeth were divided into three groups: group A consisted of Sealite® Ultra, group B consisted of K-Sealer®, and group C consisted of BioRoot® RC. After 2 months of incubation (37°C, 100% humidity) and after cutting out 2 mm from the most apical portion of the root apex, six slices of 1 mm thickness were generated. Mechanical dislodgement resistance was examined using a universal pressure-testing machine and the push-out bond strength (POBS) was calculated. Specimens were examined under 20× magnification to define the bond failure mode. Statistical analysis was executed using ANOVA, post hoc Turkey test for pairwise comparisons and Kruskal-Wallis tests. The POBS of BioRoot® was significantly higher than the POBS of the two other sealers with a mean of 10.54 MPa ± 2.10 and 5.73 MPa ± 2.34, respectively (p < 0.001). Sealite® and K-Sealer® showed similar results in the median and coronal part. K-Sealer® revealed highest POBS compared with Sealite® in the apical part (p < 0.05). The POBS of the zinc oxide and calcium silicate-based sealer was significantly lower compared with calcium silicate. Sealite® and K-Sealer® exhibited almost same results. BioRoot showed the highest POBS of all sealers. The current study was needed to evaluate the bond strength of three different cements to dentinal walls, by evaluating their respective POBS in vitro. The findings of this study may provide guidance for the clinician in the selection of an adequate endodontic sealer that guarantees an enhanced adhesive seal between the Gutta-percha and the dentinal canal walls. How to cite this article: Makhlouf MP, El Helou JD, Zogheib CE, et al. Comparative Evaluation of Push-out Bond Strength of Three Different Root Canal Sealers: An In Vitro Study. J Contemp Dent Pract 2024;25(1):15-19.

Effect of Thermo-mechanical Cycling on Fracture Resistance of Different CAD/CAM Crowns: An In Vitro Study.

To evaluate the effect of thermo-mechanical cycling (TMC) on fracture resistance of different computer-aided design/computer-aided manufacture (CAD/CAM) crowns. A total of 42 CAD/CAM crowns were fabricated on epoxy resin maxillary first premolar teeth and divided into three groups (n = 14) according to the material used: IPS e.max CAD (Ivoclar Vivadent) lithium disilicate (LD), Vita ENAMIC (VE) (VITA Zahnfabrik), Tetric CAD (Ivoclar Vivadent). Also, each group was subdivided into two equal subgroups according to TMC (n = 7). Subgroups (O) without TMC and subgroup (W) with TMC (5-55°C, 30 second, 75,000 cycles). All samples in each group were cemented with a universal bond (Tetric N bond universal) and adhesive resin cement (Variolink Esthetic DC) (Ivoclar Vivadent). Subsequently, the samples were loaded to failure in a universal testing machine at a crosshead speed of 1 mm/min, and the fracture pattern and the fracture resistance in each group were recorded. Fracture resistance was analyzed by one-way analysis of variance (ANOVA) test, followed by Tukey's post hoc test for pairwise comparison. Fracture resistance showed a significant difference between the tested groups before and after TMC; IPS e.max CAD has the highest value (1233.35 ± 97.72, 1165.73 ± 199.54 N) followed by Tetric CAD (927.62 ± 42.5, 992.04 ± 53.46 N) and Vita ENAMIC has lowest value (506.49 ± 74.24, 354.69 ± 90.36 N). Thermo-mechanical cycling affected the fracture resistance of both polymer-based CAD/CAM crowns. For dental practitioners, both IPS e.max CAD and Tetric CAD can be used clinically for posterior teeth, providing satisfactory results and resistance to fracture. How to cite this article: Elmokadem MI, Haggag KM, Mohamed HR. Effect of Thermo-mechanical Cycling on Fracture Resistance of Different CAD/CAM Crowns: An In Vitro Study. J Contemp Dent Pract 2024;25(1):29-34.

Use of the USCOM® noninvasive cardiac output measurement system to predict the development of pre-eclampsia in hypertensive pregnancies

ABSTRACT Objectives To assess the ability of the USCOM® (USCOM), using measurements of cardiac output (CO) and systemic vascular resistance (SVR), to predict the development of pre-eclampsia (PE) and severe PE in hypertensive pregnancies. Study design Prospective cohort study of women in the second or third trimester recruited at a tertiary center in Sydney, Australia. Demographic data and hemodynamic measurements using the USCOM were taken for all study participants at recruitment. Pregnancy outcome, including development of PE and severe PE, was tracked. Data were analyzed using ANOVA testing, pair-wise comparison testing, and Student’s t-testing. Results Recruitment included 65 normotensive controls, 34 women with chronic hypertension (CH), 51 with gestational hypertension (GH), and 21 with PE. Significantly higher weight, body surface area, and blood pressure measurements were found in the hypertensive, compared with the normotensive control and pregnancies. There were no observed differences in USCOM-measured CO, cardiac index, SVR, or systemic vascular resistance index between hypertensive women who did versus did not develop PE or severe PE in later pregnancy. Analysis of the CH and GH subgroups, as well as only unmedicated hypertensive women (n = 24), also showed no significant difference in hemodynamic parameters between those who did or did not develop PE or severe PE. Conclusions Our group was unable to successfully predict the onset of PE or severe PE based on hemodynamic parameters measured with the USCOM. It is possible this relates to the high proportion of women on antihypertensive medication at recruitment.

The COVID-19 lockdown as a model of detraining in division 1 college softball players

BackgroundThe COVID-19 pandemic interrupted the organized training of softball players, similar to the abrupt cessation of sports participation that can happen after an injury. Thus, the COVID-19 pandemic offers a unique model to study how sudden detraining influences softball players.MethodsWe recruited a sample of convenience of National Collegiate Athletic Association Division 1 softball players. They participated in three data collections: pre-lockdown (Jan 2020, T1), post-lockdown (Sept 2020, T2), and before the 2021 season (Jan 2021, T3). Between T1 and T2, players received an at-home conditioning and throwing program, but compliance was not strictly monitored. Between T2-T3, players resumed formal fall training (team-organized workouts, on-field practice, and within-team scrimmage games). At each time point, we collected bilaterally: 1) shoulder internal rotation (IR) and external rotation (ER) range of motion (ROM); 2) shoulder IR and ER strength; 3) hip IR and ER ROM; and 4) hip abduction and extension strength. We used four independent (2 Sides × 3 Timepoints) MANOVA with repeated measures; we followed up significant MANOVA main effect of time with Sidak posthoc tests for pairwise comparisons between time points.ResultsFifteen players participated in this study. We found a significant MANOVA main effect of time for shoulder and hip ROM (p < 0.01). Between T1-T2, dominant shoulder ER ROM decreased 6.5°, dominant shoulder IR ROM increased 4.3°, and lead hip IR ROM increased 4.4°. Between T2-T3, dominant shoulder ER ROM increased 6.3° and trail hip ER ROM increased 5.9°. We found a significant MANOVA main effect of time for shoulder strength (p = 0.03) but not for hip strength (p = 0.18). Between T2-T3, non-dominant shoulder IR and ER increased 1.8 kg and 1.5 kg, respectively.ConclusionA sudden and prolonged cessation of organized training generated changes in shoulder and hip ROM but affected strength to a lesser extent. The loss of shoulder ER and increased lead hip IR ROM are maladaptive as they are associated with injury in overhead athletes. Resuming team-organized training and scrimmage reversed some (shoulder ER), but not all of these changes. Practitioners should monitor clinical variables regularly and be aware of potential changes due to unexpected and prolonged interruptions in training, such as when players suffer sports-related injuries.

Perceptions of forest product businesses employees in Turkey regarding occupational health and safety during the COVID-19 pandemic.

The COVID-19 pandemic has undeniably brought up the issue of Occupational Health and Safety (OHS) for businesses in Turkey. In this global pandemic, strategies developed to effectively address OHS risks and eliminate them with reliable, high-quality data have gained importance. This study aimed to determine the perceptions of employees in the forest products industry in Turkey regarding the OHS during the COVID-19 pandemic. The sample of the descriptive and analytical study consisted of a total of 371 employees in forest product businesses located in Turkey. The sample of the study was determined by the purpose-based sampling method. Data were collected both online and face-to-face from June 2022 to October 2022. The data were obtained using the Questionnaire of Employee and Business Characteristics and the Scale of Employees' Perceptions on the OHS (S-POHS) adapted by Özden (2022). Statistical analysis was performed using SPSS and calculated by descriptive analyses, pairwise comparison tests and multivariate regression analyses. 39.1% of the employees with a mean age of 34.12±8.78 years are high school graduates and 61.5% are workers. Significant differences were found in the S-POHS average scores of the employees in the businesses that produce paper-cardboard, have operated for less than 20 years, have a partnership structure with foreign capital and have an OHS Management System Quality Certificate (p < 0.05). While a positive OHS perception level has already been achieved in the forest products industry in business administrations and by employees, it is clear that this should not be lost and it should be prepared for the next crises by adding new applications.

Türkiye, Covid-19 Kapanma ve Kısmi Kapanma Dönemlerinde Hava Kirliliğinde Azalmalar Yaşadı Mı?

Air pollution, one of humanity's essential environmental problems due to the increasing population and urbanization, negatively affects the ecosystem and public health. During reduced human activity, such as martial law, war, and pandemics like COVID-19, improvements in air quality may be observed due to diminished anthropogenic impact. The novel coronavirus, COVID-19, has caused widespread illness and fatalities. The World Health Organization (WHO) declared a state of emergency at the end of December 2019 following the first recognition of the virus in Wuhan. The Turkish government declared this state on March 11, 2020, and implemented some measures, including a lockdown (LD) and a partial lockdown (PLD), to protect public and human health. The present study aims to determine the impact of LD and PLD on the air quality of fourteen selected cities in Turkey that participated in all LDs during the state of emergency on weekends and national and religious holidays. The hourly air quality data used in the study were collected from 105 air monitoring stations in fourteen cities. The non-parametric Kruskal Wallis test, followed by the Dunn's Bonferroni test for pairwise comparison, was employed to determine the differences in air quality between years. The findings indicated significant reductions in air pollution during LD and PLD: 21.1-40.3% and 8.9-29.8% in PM10, respectively, and 30.2-50.8% and 2.6-22.4% in NOx, respectively. SO2 and CO also varied significantly. While the changes in SO2 during LD and PLD went from 0.0% to 5.7% and -2.4% to 1.2%, respectively, those in CO ranged from -6.6% to 29.6% and 1.3% to 33.2%, respectively.