A Promising Potential of Brown Algae Sargassum polycystum as Irreversible Hydrocolloid Impression Material

This study aimed to investigate the potential use of brown algae Sargassum polycystum as irreversible hydrocolloid (alginate) impression material. Potassium alginate extracted from Sargassum polycystum was prepared in three different compositions (14%, 15%, and 16%) and mixed with other standard components to form an alginate impression material. Prior to that, the purity of potassium alginate was quantified with Fourier Transform Infrared Spectroscopy (FTIR) analysis. As a control material, the alginate impression material from a commercially available product was used. All alginate impression materials were then applied to a die stone model. Dimensional accuracy was measured by calculating the mesiodistal width of incisors in the generated dental cast using a digital caliper 0.01 accuracy (five replications). In addition, to evaluate the dimensional stability, the impression results were poured at four different periods (immediately, 5 min, 10 min, and 15 min). An independent t-test was performed to compare the measurement results with p < 0.05 considered significant. Analytical results confirm that the impression material containing 15% potassium alginate gives the best dimensional accuracy similar to control (p > 0.05). Meanwhile, the optimal dimensional stability was produced in the impression material containing 16% potassium alginate. Our study suggested that brown algae Sargassum polycystum has a promising potential to be used as an alginate impression material in clinical application.

Influence of Voxel Size on CBCT Images for Dental Implants Planning

Objective This study was developed to evaluate the influence of voxel size on bone measurements for implant planning. Materials and Methods The research was performed by using edentulous synthetic human mandibles with different levels of bone resorption. For each mandible, height and bone thickness were measured with a digital caliper. The PaX-i3d device was used to acquire the volumes of the five mandibles, with 50kVp, 4 mA, and a voxel size of 0.08 mm. After the acquisition, the images were reconstructed in the software CS three-dimensional Imaging, with four different sizes of voxels: 0.1, 0.2, 0.3, and 0.4 mm. All volumes were analyzed by a single evaluator who performed measurements to obtain bone height and thickness, using the reference points that were considered in obtaining the gold standard. The data were analyzed by ANOVA with a significance level of 5%. Results There was no significant difference in the measurements obtained with different voxel sizes, both for bone height measurements and bone thickness. There was no statistically significant difference in measurements in thickness in comparison to the gold standard. Conclusion When necessary, to measure height and bone thickness, it is possible to recommend voxel images of larger size (0.40 mm) without compromising the quality of the patient's clinical planning.

Microbiological Antibiotic Assay Validation of Gentamicin Sulfate Using Two-Dose Parallel Line Model (PLM)

Till nowadays microbiological assay is still widely used with several antibiotics that are composed of a mixture of related active compounds. However, obtaining a reasonably valid determination of the potency is dependent on the validity and the suitability of the assay design. The present work aimed to validate an assay design of an aminoglycoside antibiotic (Gentamicin Sulfate) using a two-dose Parallel Line Model agar diffusion assay in a large 8×8 rectangular plate. All preparatory procedures were done following United States Pharmacopeia and the Inhibition Zones were measured using a digital caliper to the nearest 0.01 mm. Analysis of variance of compendial requirements of regression and parallelism were found to be satisfactorily meeting the acceptance criteria. Specificity was achieved for the product under investigation with no detectable IZ that could be found for all components except the antibiotic. The validation method showed acceptable linearity of r2≥0.98. Accuracy and precision parameters showed RSD (%)<2. All relative error value estimates were below 4%. The proposed validation design for 32×32 cm antibiotic plates yielded valid results and can be projected for the routine Quality Control analysis of the antibiotic material, especially which is incorporated into a finished medicinal dosage form. Doi: 10.28991/HIJ-2021-02-04-04 Full Text: PDF

Estimation of Maxillary Anterior Teeth Width with Golden Proportion in Undergraduate Students

Aim: To estimate the frequency of coinciding width of maxillary front teeth and golden proportion ratio in undergraduate students. Study design: Descriptive Cross Sectional Place and Duration of Study: Department of Prosthodontics, Liaquat Medical University Hospital from June 2019 to January2020. Methodology: Total numbers of 96 students with maxillary anterior teeth were selected in this study. Appropriate size of upper maxillary impression of maxillary arch was made using alginate impression material with manufacturer prescribed instructions. The cast was retrieved between one and three hours of pouring. Digital caliper was used to measure for the spaces in the. The final recordings were entered in proforma. The data was analyzed by SPSS version-20. Results: Among the participants 65% were males and 35% females. The mean age of the participants was 21.02±1.88 years. Rate of coinciding was significantly high in 18 to 20 years of age (p=0.032).Coinciding width of maxillary anterior teeth and golden proportion ratio was significantly high in 1st year student (p=0.038) Conclusion: It was concluded that esthetics in dentistry cannot be justified mathematically and individuals should not be standardized. Whereas the dentists should follow few fundamental guidelines in the planning for esthetic treatment, it should be acknowledged that esthetics alters from person to person. That’s why it is important to consider the dento-facial specificities of every person and the inconstant natural tooth proportion during restoration or replacement of the maxillary front teeth.

Hand anthropometry survey in Iranian adults and comparisons with other populations

BACKGROUND: Hand anthropometry is useful for designing manual systems such as hand tools, controls, and gloves. There are limited published data on the hand dimensions of Iranian male and female adults. OBJECTIVE: This study was undertaken to measure the hand anthropometric dimensions in Iranian adults to compare data between two genders and also with the corresponding data from other nationalities. METHODS: A total of 34 dimensions of the right hand were measured in 217 male and 128 female adults using a digital caliper and tape. The mean, standard deviation, and the main percentiles are summarized in a table and the mean of each dimension is compared by independent t-tests between genders. Hand dimensions are compared between Iranian and other nationalities such as North Colombian, Korean, Turkish, Nigerian, Bangladeshi, Jordanian, and Vietnamese using the published data. RESULTS: Females had significantly smaller hand dimensions than males in all dimensions ranged from 4.21%to 18.16%, with the largest differences in hand breadths. Compared with other nationalities, the Iranian male and female adults had wider (greater breadth and circumferences) hands with shorter fingers. CONCLUSIONS: The results showed significant differences of hand anthropometry between Iranian and other nationalities which should be included in the design and selection of hand tools for Iranian population.

A morphometric study on the articulating facets of talus in North Indian population

Background: Morphometry of talus will be helpful for radiologists, orthopaedicians and surgeons for diagnosis and treatment of talar fractures and making bone prosthesis. Aims and Objectives: The purpose of our study is to do a morphometric analysis of talus to facilitate orthopedicians in planning surgeries for subtalar implants and foot prostheses. This will be of great use to forensic anthropologists. Materials and Methods: For the study, 60 dry adult human tali (24 left and 26 right) were obtained from the Department of Anatomy, SGT Medical College, Budhera. The morphometry of talar surfaces was done using a digital caliper accurate to 0.01 mm and data was recorded. Results: The mean values of medial, central and lateral length on the trochlear surface were 27.0cm, 28.1cm, 27.4cm on right side and 29.4cm, 27.0cm, 29.1cm on left side. Mean anterior, central and posterior widths on the trochlear surface were 27.6cm, 26.2cm, 21.1cm on right side and 27.0cm, 24.0cm, 23.1cm on left side. The mean central height and width on the lateral articular surface was 26.2 cm and 21.9 cm on the right side respectively and 23.0 cm and 16.8 cm on the left side respectively. The mean central height and central width on the medial articular surface was 13.6 cm and 25.9 cm on the right side respectively and 10.8cm and 17.9 cm on the left side respectively. Conclusions: The current study would be helpful as an important tool for reconstruction surgeries of hindfoot deformities and foot reconstruction procedures. Also it would be useful to orthopaedicians to design accurate talus bone prosthesis and talar implants. Morphometry of talus will be of use in objective categorization and racedetermination for forensic purposes.

Relationship Between the Cost of 12 Light-curing Units and Their Radiant Power, Emission Spectrum, Radiant Exitance, and Beam Profile

SUMMARY Objectives: To correlate the radiant power (mW), radiant exitance (or tip irradiance in mW/cm2), emission spectrum (mW/cm2/nm), and beam irradiance profile of 12 light-curing units (LCUs) available in the Brazilian market with their market cost. Methods and Materials: Six LCUs that cost more than US$900 (Bluephase G4,VALO Grand, VALO Cordless, Radii Xpert, Elipar DeepCure-S, and Radii plus) and six low-cost LCUs costing less than US$500 (Radii Cal, Optilight Max, High Power LED 3M, Emitter D, Emitter C, and LED B) were examined. Radiant power (mW) and emission spectrum (mW/nm) were measured using an integrating sphere connected to a fiber-optic spectroradiometer. The internal tip diameter (mm) of each LCU was measured using a digital caliper and was used to calculate the average radiant exitance (mW/cm2). Irradiance profiles at the light tip were measured using a commercial laser beam profiler. The cost of each LCU in Brazil was correlated with internal tip diameter, radiant power, and tip irradiance. Results: None of the low-cost LCUs were broad spectrum multiple peak LCUs. There was no correlation between the cost of the LCUs and their averaged tip irradiance; however, there was a high positive correlation between the cost of the LCUs and the radiant power and tip diameter. The VALO Grand, Elipar DeepCure-S, VALO Cordless, and Bluephase G4 all emitted a higher radiant power. They also had a significantly greater tip diameter than other LCUs. For the LCUs with a nonuniform output, some areas of the light tip delivered less than 400 mW/cm2, while other areas delivered more than 2500 mW/cm2. Conclusions: In general, LCUs that had a higher cost (US$971-US$1800) delivered more power (mW) and had a greater tip diameter (mm), which covered more of a tooth. In general, the low-cost LCUs (US$224-US$470) emitted a lower radiant power and had a smaller tip diameter.

Perforating Arteries of the Lemniscal Trigone: A Microsurgical Neuroanatomic Description

Background: The perforating arteries in the dorsolateral zone of the midbrain play a crucial role in the functions of the brain stem. Their damage due to herniation, pathological lesions, or surgery, favored by the narrow tentorial incisura, can lead to hemorrhages or ischemia and subsequently to severe consequences for the patient.Objective: In literature, not much attention has been directed to the perforating arteries in the lemniscus; in fact, no reports on the perforators of this anatomical region are available. The present study aims to a detailed analysis of the microanatomy and the clinical implications of these perforators, in relation to the parent vessels. We focused on the small vessels that penetrate the midbrain's dorsolateral surface, known as lemniscal trigone, to understand better their microanatomy and their functional importance in the clinical practice during the microsurgical approach to this area.Methods: Eighty-seven alcohol-fixed cadaveric hemispheres (44 brains) without any pathological lesions provided the material for studying the perforating vessels and their origin around the dorsolateral midbrain using an operating microscope (OPMI 1 FC, Zeiss). Measurements of the perforators' distances, in relation to the parent vessels, were taken using a digital caliper.Results: An origin from the SCA could be found in 70.11% (61) and from the PCA in 27.58% (24) of the hemispheres. In one hemisphere, an origin from the posterior choroidal artery was found (4.54%). No perforating branches were discovered in 8.04% of specimens (7).Conclusion: The perforating arteries of the lemniscal trigone stem not only from the superior cerebellar artery (SCA), as described in the few studies available in literature, but also from the posterior cerebral artery (PCA). Therefore, special attention should be paid during surgery to spare those vessels and associated perforators. A comprehensive understanding of the lemniscal trigone's perforating arteries is vital to avoid infarction of the brainstem when treating midbrain tumors or vascular malformations.

Manual kidney stone size measurements in computed tomography are most accurate using multiplanar image reformatations and bone window settings

Computed tomography in suspected urolithiasis provides information about the presence, location and size of stones. Particularly stone size is a key parameter in treatment decision; however, data on impact of reformatation and measurement strategies is sparse. This study aimed to investigate the influence of different image reformatations, slice thicknesses and window settings on stone size measurements. Reference stone sizes of 47 kidney stones representative for clinically encountered compositions were measured manually using a digital caliper (Man-M). Afterwards stones were placed in a 3D-printed, semi-anthropomorphic phantom, and scanned using a low dose protocol (CTDIvol 2 mGy). Images were reconstructed using hybrid-iterative and model-based iterative reconstruction algorithms (HIR, MBIR) with different slice thicknesses. Two independent readers measured largest stone diameter on axial (2 mm and 5 mm) and multiplanar reformatations (based upon 0.67 mm reconstructions) using different window settings (soft-tissue and bone). Statistics were conducted using ANOVA ± correction for multiple comparisons. Overall stone size in CT was underestimated compared to Man-M (8.8 ± 2.9 vs. 7.7 ± 2.7 mm, p < 0.05), yet closely correlated (r = 0.70). Reconstruction algorithm and slice thickness did not significantly impact measurements (p > 0.05), while image reformatations and window settings did (p < 0.05). CT measurements using multiplanar reformatation with a bone window setting showed closest agreement with Man-M (8.7 ± 3.1 vs. 8.8 ± 2.9 mm, p < 0.05, r = 0.83). Manual CT-based stone size measurements are most accurate using multiplanar image reformatation with a bone window setting, while measurements on axial planes with different slice thicknesses underestimate true stone size. Therefore, this procedure is recommended when impacting treatment decision.

Granulometric Parameters of Solid Blueberry Fertilizers and Their Suitability for Precision Fertilization

For precise fertilization of blueberry plants, it is technologically the easiest and most suitable option to use a volumetric filling, for which it can be presumed that it is possible to precisely dose the fertilizer for each plant by grams. For setting up a volumetric filler, it is necessary to know parameters such as the size of the fertilizer particles and their bulk density. The aim of this research is to determine the granulometric parameters and their effect, which is done by measuring up three different fertilizers (SQM Qrop K, Memon Siforga, Substral): width, height, and length of 100 randomly selected fertilizer particles as well as the volumes and weights of 100 particles in 10 repetitions. According to the measurements, the average diameters of fertilizer particles were found as well as the average mass, volumes, and bulk density. A Mahr Digital Caliper 16EWRi 0–150 mm was used to measure the diameters of the fertilizer granules. A Yxlon FF35 computer tomograph was used to accurately scan particles. The analytical scale, Kern ABJ 220-4NM, was used to determine mass. The volumes were measured, using measuring glasses, with one having a maximum volume of 10 mL in 0.2 mL increments and another having a maximum volume of 100 mL in 1 mL increments. Descriptive statistics analysis was performed in Microsoft Excel. It turned out that the average diameters (3.68 vs. 3.64 vs. 4.29 mm) and bulk densities (0.928 vs. 0.631 vs. 0.824 g cm−3) of the three fertilizers differed far from each other, meaning that the given volume could be filled with different amounts of fertilizer. Equations between mass and weight were formed according to the measurements. As a result, it was found that a volumetric filler can be used for fertilizing blueberry plants precisely, but it demands adjusting the filler each time in the situation, which is defined by the variety of blueberry plants: their age, size, and health.