scholarly journals Surface detail reproduction and dimensional accuracy of stone models: influence of disinfectant solutions and alginate impression materials

2012 ◽  
Vol 23 (4) ◽  
pp. 417-421 ◽  
Author(s):  
Ricardo Danil Guiraldo ◽  
Thaís Teixeira Borsato ◽  
Sandrine Bittencourt Berger ◽  
Murilo Baena Lopes ◽  
Alcides Gonini-Jr ◽  
...  
Keyword(s):  
Sodium Hypochlorite ◽  
Dimensional Accuracy ◽  
Chlorhexidine Digluconate ◽  
Mean Values ◽  
Impression Materials ◽  
Significant Difference ◽  
Disinfection Procedure ◽  
The Mean ◽  
Surface Detail ◽  
Materials Used

This study compared the surface detail reproduction and dimensional accuracy of stone models obtained from molds disinfected with 2% sodium hypochlorite, 2% chlorhexidine digluconate or 0.2% peracetic acid to models produced using molds which were not disinfected, with 3 alginate materials (Cavex ColorChange, Hydrogum 5 and Jeltrate Plus). The molds were prepared over matrix containing 20-, 50-, and 75-µm lines, performed under pressure with perforated metal tray. The molds were removed following gelation and either disinfected (using one of the solutions by spraying followed by storage in closed jars for 15 min) or not disinfected. The samples were divided into 12 groups (n=5). Molds were filled with dental gypsum Durone IV and 1 h after the start of the stone mixing the models were separated from the tray. Surface detail reproduction and dimensional accuracy were evaluated using optical microscopy on the 50-µm line with 25 mm in length, in accordance with the ISO 1563 standard. The dimensional accuracy results (%) were subjected to ANOVA. The 50 µm-line was completely reproduced by all alginate impression materials regardless of the disinfection procedure. There was no statistically significant difference in the mean values of dimensional accuracy in combinations between disinfectant procedure and alginate impression material (p=0.2130) or for independent factors. The disinfectant solutions and alginate materials used in this study are no factors of choice regarding the surface detail reproduction and dimensional accuracy of stone models.

Effect of Intermixing Brands on the Dimensional Accuracy of Master Cast using Putty-wash Impression Technique

2016 ◽  
Vol 17 (9) ◽  
pp. 734-739
Author(s):  
Mohammed E Sayed ◽  
Bandar MA Al-Makramani ◽  
Fuad A Al-Sanabani ◽  
Mohamed S Mohamed
Keyword(s):  
Stainless Steel ◽  
Dimensional Accuracy ◽  
Mean Value ◽  
Two Dimensions ◽  
Impression Material ◽  
Impression Technique ◽  
Impression Materials ◽  
Significant Difference ◽  
The Mean ◽  
Post Hoc

ABSTRACT Aim The aim of this study was to evaluate the effect of intermixing brands of addition silicone impression materials on the dimensional accuracy of stone models using two-step putty-wash technique. Materials and methods Two common brands of addition silicone impression material (Express and Aquasil) were used in this study. A total of 40 impressions of a stainless steel model simulating a three-unit bridge were made, 10 impressions for each group. Accuracy was assessed by measuring two dimensions (inter-abutment and intra-abutment) on stone models obtained from impressions of the stainless steel model. Each sample was measured thrice and the mean value was calculated. The data were analyzed using analysis of variance (ANOVA) and Scheffe's post hoc test. Results The results indicated that each of the inter-abutment and intra-abutment dimensions of the stone models was significantly higher than those for the stainless steel model (p < 0.001). However, there was no statistically significant difference in each of the inter-abutment and intra-abutment dimensions of the stone models among the four tested groups (p < 0.05). Conclusion The results obtained were statistically analyzed and the values of the inter-abutment and intra-abutment dimensions were all within the clinically acceptable range. Clinical significance Intermixing brands of additional silicone impression materials evaluated in this study did not affect the dimensional accuracy of obtained stone casts. This will help to minimize the wastage of materials due to lack of either light or putty consistency of the same brand of additional silicone impression material. How to cite this article Sayed ME, Al-Makramani BMA, Al-Sanabani FA, Mohamed MS. Effect of Intermixing Brands on the Dimensional Accuracy of Master Cast using Putty-wash Impression Technique. J Contemp Dent Pract 2016;17(9):734-739.

A Comparative Evaluation of Dimensional Accuracy and Surface Detail Reproduction for Polyvinyl Siloxane and Vinyl Siloxane Ether under Dry and Moist Conditions- An In-vitro Study

2021 ◽  
Author(s):  
Amit Baban Pokharkar ◽  
Umesh Gopal Palekar ◽  
Veena Saraf ◽  
Deepak Machindra Vikhe ◽  
Shefali Sevakram Bhiwapurkar ◽  
...  
Keyword(s):  
Statistical Difference ◽  
In Vitro Study ◽  
Dimensional Accuracy ◽  
Dimensional Change ◽  
Vitro Study ◽  
Significant Difference ◽  
Moist Condition ◽  
The Mean ◽  
Surface Detail

Introduction: The conventional impression procedure plays a major role in prosthodontics inspite of advancement in intra- oral scanning devices and 3D imaging procedures. Dimensional accuracy and surface detail reproduction are important for recording an impression. Aim: The study evaluated and compared the dimensional accuracy and surface detail reproduction of Polyvinyl Siloxane (PVS) and vinyl siloxane ether impression materials when used under dry and moist conditions. Materials and Methods: An in-vitro study was conducted in the Department of Prosthodontics, Rural Dental College, Pravara Institute of Medical Sciences, Loni, Ahmednagar, Maharashtra, India, for a period of two years from October 2018 to September 2020. A total of 60 impressions were made with PVS (Group A) and vinyl siloxane ether (Group B) under dry (A1, B1) and moist (A2, B2) conditions of stainless steel dies which had lines engraved on superior surface of the die. Using a Harloc’s Tool maker’s microscope, dimensional accuracy was measured by comparing the width of line Y in each impression. Surface detail reproduction was evaluated by American Dental Association (ADA) specification no. 19 where it stated continuous replication of at least any two lines out of the three lines inscribed on the die. Data analysis processing was performed in the SYSTAT version 12 (made by Crane’s software, Bangalore). Student’s unpaired t-test and Chi-square test were performed to determine statistical difference between PVS and vinyl siloxane ether where the level of significance was set at 5% and 1%. Results: The mean dimensional change and SD values for PVS under dry condition ranged from 21.93±2.46 to 22.40±2.89 (in mm). The mean dimensional change and SD values for PVS under moist condition ranged from 22.87±3.20 to 23.33±3.42. The mean dimensional change and SD values for vinyl siloxane ether under dry condition ranged from 21.93±3.61 to 24.73±5.20. The mean dimensional change and SD values for vinyl siloxane ether under moist condition ranged from 21.93±4.48 to 22.87±4.15. No statistical difference was found under dry and moist conditions within 2 hours and after 24 hours for both the materials. Conclusion: The study revealed no significant difference between dimensional accuracy and surface detail reproduction for PVS and vinyl siloxane ether. Both the materials can reproduce the details under dry and moist conditions satisfactorily and remained dimensionally stable till 24 hours after impression making.

scholarly journals Comparison of Some Mechanical and Physical Properties of three Types of Impression Materials with Different Dental Implant Angulations

2018 ◽  
Vol 11 (3) ◽  
pp. 1359-1368
Author(s):  
Dhuha H. Mohammed ◽  
Abdalbseet A. Fatalla ◽  
Ghassak H. Jani
Keyword(s):  
Contact Angle ◽  
Dimensional Accuracy ◽  
Mean Value ◽  
Distance Measurements ◽  
Tear Strength ◽  
Impression Material ◽  
Mean Values ◽  
Impression Materials ◽  
Linear Distance ◽  
Significant Difference

Choosing an appropriate impression material is a challenge for many dentists, yet an essential component to provide an excellent clinical outcome and improve productivity and profit. The purpose of present study was to compare wettability, tear strength and dimensional accuracy of three elastomeric impression materials, with the same consistencies (light-body). Three commercially available light body consistency and regular set 3M ESPE Express polyvinylsiloxane (PVS), 3M ESPE Permadyne polyether (PE), and Identium (ID), impression materials were comparedTear strength test, contact angle test and linear dimensional accuracy were evaluated for three elastic impression material. Among the three experimental groups PE impression material exhibited the higher mean values of tear strength, followed by ID group then PVS which showed the lowest mean value. For wettability test, Polyether group exhibited the lowest mean values of contact angle, followed by mean values of contact angle of ID group, while the PVS group showed the highest contact angle. There was a significant difference in the linear distance measurements between the two parallel impression coping/analogue assembly of the working models obtained by using (Identium, 3M ESPE ExpressPVS , 3M ESPE Permadyne polyether) the polyether impression materials provide higher tear strengths and lower wettability than elastomer impression materials and Identium material have acceptable tear strengths and wettability. All three experimental impression materials were distorted in both conditions (angled and parallel implant situations)

A COMPARISON OF TWO METHODS FOR MEASUREMENT OF ALDOSTERONE SECRETION RATE IN MAN

1966 ◽  
Vol 53 (2) ◽  
pp. 177-188 ◽  
Author(s):  
P. Lund-Johansen ◽  
T. Thorsen ◽  
K. F. Støa
Keyword(s):  
Urinary Excretion ◽  
Normal Subjects ◽  
Secretion Rate ◽  
Aldosterone Secretion ◽  
Simple Method ◽  
Mean Values ◽  
Pathological Conditions ◽  
Significant Difference ◽  
Derivative Method ◽  
The Mean

ABSTRACT A comparison has been made between (A), a relatively simple method for the measurement of aldosterone secretion rate, based on paper chromatography and direct densitometry of the aldosterone spot and (B) a more elaborate isotope derivative method. The mean secretion rate in 9 normal subjects was 112 ± 26 μg per 24 hours (method A) and 135 ± 35 μg per 24 hours (method B). The »secretion rate« in one adrenalectomized subject after the intravenous injection of 250 μg of aldosterone was 230 μg per 24 hours (method A) and 294 μg per 24 hours (method B). There was no significant difference in the mean values, and correlation between the two methods was good (r = 0.80). It is concluded that the densitometric method is suitable for clinical purposes as well as research, being more rapid and less expensive than the isotope derivative method. Method A also measures the urinary excretion of the aldosterone 3-oxo-conjugate, which is of interest in many pathological conditions. The densitometric method is obviously the less sensitive and a prerequisite for its use is an aldosterone secretion of 20—30 μg per 24 hours. Lower values are, however, rare in adults.

CONCENTRADO PROTEICO OBTIDO DAS FOLHAS DE MANDIOCA (Manihot esculenta Crantz) DE TRÊS VARIEDADES COMERCIAIS.

2017 ◽  
Vol 13 (1) ◽  
Author(s):  
Izabel Aparecida Soares ◽  
Mauro Sérgio Téo ◽  
Carlise DEBASTIANI ◽  
Suzymeire BARONI ◽  
Vanessa Silva RETUCI
Keyword(s):  
Manihot Esculenta ◽  
Crude Protein ◽  
Hydrocyanic Acid ◽  
Protein Concentrate ◽  
Manihot Esculenta Crantz ◽  
White Variety ◽  
Mean Values ◽  
Randomized Design ◽  
Significant Difference ◽  
The Mean

O trabalho teve por objetivo verificar diferenças entre rendimento do concentrado proteico e proteína bruta da folha da mandioca (Manihot esculenta Crantz), obtidos a partir de três variedades comerciais: branca, cascuda e vermelha. As manivas foram plantadas seguindo o delineamento experimental inteiramente casualizado com três repetições. Nas comparações entre as variedades, considerou coletas escalonadas pós-plantio, realizadas aos 12, 14 e 16 meses. O concentrado proteico foi obtido a partir da farinha das folhas inteiras e submetido ao método de termo - coagulação ácido e a proteína bruta pelo método padrão AOAC. Os dados foram submetidos a análise de variância e comparados pelo teste de Tukey - 5% de probabilidade. Os resultados não indicaram diferença significativa entre as médias obtidas para rendimento de concentrado proteico. Para a variável porcentagem de proteína bruta a variedade Branca foi a que apresentou maior valor, com média de 46,25%, seguida pela Cascuda e Vermelha, 44,52% e 37,30%, sucessivamente. Conclui-se que outros estudos devem avaliar condições que possam influenciar no teor de proteína foliar, como clima e solo, e, avaliar os níveis de ácido cianídrico de cada variedade, indicando qual das três é a melhor para a extração do concentrado proteico das folhas. Palavras chaves: Manihot esculenta Crantz, variedades comerciais, concentrado proteico, proteína bruta. ABSTRACT: The study aimed to assess the differences between income protein concentrate, crude protein of cassava leaf (Manihot esculenta Crantz), obtained from three commercial varieties: white, red and cascuda. The cuttings were planted following the completely randomized design with three replications. Comparisons between the varieties considered after planting staggered collections, held on 12, 14 and 16 months. The protein concentrate was obtained from flour of whole sheets and subjected to the term method - acid coagulation and crude protein by AOAC standard method. The data were submitted to ANOVA and Tukey test - 5% probability. The results indicated no significant difference between the mean values obtained for protein concentrate income. For the variable percentage of crude protein White variety showed the highest, with an average of 46.25%, followed by cascuda and Red, 44.52% and 37.30%, successively. We conclude that further studies should evaluate conditions that may affect the leaf protein content, such as climate and soil, and evaluate the hydrocyanic acid levels of each variety, indicating which of the three is the best for the extraction of protein concentrate from leaves Key words: Manihot esculenta Crantz, commercial varieties, protein concentrate, crude protein.

Comparative Study to Evaluate the Surface Detail Reproduction of Dental Stone after Immersion in Various Different Disinfectant Solutions, Under Stereomicroscope 10 X Magnification –An In-Vitro Study

2017 ◽  
Vol 9 (3) ◽  
Author(s):  
Rathika Rai ◽  
M. A. Easwaran ◽  
K. T. Dhivya
Keyword(s):  
Sodium Hypochlorite ◽  
In Vitro Study ◽  
Control Group ◽  
Immersion Method ◽  
Significant Difference ◽  
Surface Irregularities ◽  
Disinfectant Solution ◽  
Surface Detail ◽  
Group B

Aim: To evaluate the surface detail reproduction of dental stone this is immersed in different disinfectant solution and studied under stereomicroscope. Methodology: Total number of 30 specimens of dental stone (Type III) were made with measurements of 1.5cm diameter and 1cm height .This samples are divided in to 3 groups group A,B,C. were A is immersed in Distilled water which was taken as control group ;B is immersed in 2% Glutaraldehyde and C is immersed in 5%sodium hypochlorite. Each specimen were immersed in the disinfectant solution for 15 minutes and dried under room temperature for 24 hrs. After 24 hrs each specimens are studied under stereomicroscope for surface details. Result: The results showed no significant difference in the surface irregularities and porosities for a group 1 and group 2 except group 3 which showed significant increase in the porosities, surface irregularities and erosions after disinfection with 5% NaHOCl by immersion method. Conclusion: The surface detail reproduction capacity of die stone was adversely affected when 5% Sodium hypochlorite was used as disinfectant solution when compare d to control group and 2% Glutaraldehyde

scholarly journals AB0100 EVALUATION OF PGA LEVEL FOR CLINICAL REMISSION WITH BOOLEAN CRITERIA, 10MM OR 20MM?

2021 ◽  
Vol 80 (Suppl 1) ◽  
pp. 1078.1-1079
Author(s):  
I. Yoshii
Keyword(s):  
Disease Activity ◽  
Patient Group ◽  
Clinical Remission ◽  
Global Assessment ◽  
Activity Index ◽  
T Test ◽  
Mean Values ◽  
Significant Difference ◽  
Remission Criteria ◽  
The Mean

Background:Patient’s global assessment (PGA) is one important component of Boolean composite criteria for remission in treat with rheumatoid arthritis (RA). However, PGA no more than 10mm is sometimes obstacle to attain clinical remission. In recent few years, one opinion that PGA no more than 20mm may be comparable as no more than 10mm.Objectives:The aim of this study is to analyze how difference of these PGA level affect disease activity and daily activities in living, and evaluate which is optimal for the remission with Boolean remission criteria from real world setting.Methods:RA patients who were followed up for more than three years in the institute were picked up in the study. Each patient was monitored with tenderness joint count (TJC), swollen joint count (SJC), PGA, evaluator’s global assessment (EGA), serum C-reactive protein level (CRP), calculated disease activity score with simplified disease activity index(SDAI), Health Assessment Questionnaire Disability Index (HAQ-DI), and pain score using visual analog scale (PS-VAS) every consulted time from the first encounter (Baseline). Patients were classified according to achievement of Boolean remission criteria. Group 1: a patient group who attained Boolean remission wih TJC≦1, SJC≦1, CRP≦1mg/dl, and PGA≦1 (G-1), Group 2: a patient group who could not attained the Boolean remission used in the G-1 evaluation, but could attained another Boolean remission with TJC≦1, SJC≦1, CRP≦1mg/dl, and PGA≦2 (G-2), and Group 3: a patient group who could not attain Boolean remission for neither criterion.Mean values of measured parameters at Baseline and after the Baseline were compared statistically with Student T-test. Mean values of the same parameters in the G-1 and G-2 at the time of attain Boolean remission for each criteria, mean values of each of these parameters thereafter, and changes of these parameters were compared statistically with Student T-test.Results:A total of 438 patients 385 in the G-1 group, 16 in the G-2 group, and 37 in the G-3 group, were recruited. In parameters at Baseline, level of TJC, SJC, PGA, EGA, SDAI, and HAQ-DI in the G-1 was significantly lower than in the G-3, whereas no significant differences in any parameters demonstrated between in the G-2 and G-3. Level of HAQ-DI, and PS-VAS after Baseline in the G-1 was lower than in the G-3, whereas no significant difference of these parameters after Baseline demonstrated between in the G-2 and G-3. TJC, SJC, PGA, and EGA demonstrated significant less level in the G-1 than in the other two groups. The mean SDAI score at the time of first achievement of Boolean remission in the G-1 and G-2 were 1.08 and 2.57, respectively. The mean value of SDAI score after remission in the G-1 and G-2 were 3.35 and 6.44, respectively. These values and PS-VAS including change of the SDAI score demonstrated significant difference between the two groups (p<0.01), whereas HAQ-DI in the two groups demonstrated no significant difference.Conclusion:These results suggested that setting PGA as no more than 10mm should be reasonable for the evaluation of clinical remission with the Boolean criteria.Disclosure of Interests:None declared

A new simpler approach to measure the strength of toe plantar flexion requiring no mechanical restraint with a light-weight device

2021 ◽  
pp. 095441192110029
Author(s):  
Yuko Komuro ◽  
Yuji Ohta
Keyword(s):  
Plantar Flexion ◽  
Mean Value ◽  
Simple Approach ◽  
Light Weight ◽  
New Approach ◽  
Mean Values ◽  
Mechanical Restraint ◽  
Significant Difference ◽  
Ankle Joints ◽  
The Mean

Conventionally, the strength of toe plantar flexion (STPF) is measured in a seated position, in which not only the target toe joints but also the knee and particularly ankle joints, are usually restrained. We have developed an approach for the measurement of STPF which does not involve restraint and considers the interactions of adjacent joints of the lower extremities. This study aimed to evaluate this new approach and comparing with the seated approach. A thin, light-weight, rigid plate was attached to the sole of the foot in order to immobilize the toe area. Participants were 13 healthy young women (mean age: 24 ± 4 years). For measurement of STPF with the new approach, participants were instructed to stand, raise the device-wearing leg slightly, plantar flex the ankle, and push the sensor sheet with the toes to exert STPF. The sensor sheet of the F-scan II system was inserted between the foot sole and the plate. For measurement with the seated approach, participants were instructed to sit and push the sensor with the toes. They were required to maintain the hip, knee, and ankle joints at 90°. The mean values of maximum STPF of the 13 participants obtained with each approach were compared. There was no significant difference in mean value of maximum STPF when the two approaches were compared (new: 59 ± 23 N, seated: 47 ± 33 N). The coefficient of variation of maximum STPF was smaller for data obtained with the new approach (new: 39%, seated: 70%). Our simple approach enables measurement of STPF without the need for the restraints that are required for the conventional seated approach. These results suggest that the new approach is a valid method for measurement of STPF.

Spontaneous Blinks as a Criterion of Visual Fatigue during Prolonged Work on Visual Display Terminals

2001 ◽  
Vol 92 (1) ◽  
pp. 234-250 ◽  
Author(s):  
Kenichi Kaneko ◽  
Kazuyoshi Sakamoto
Keyword(s):  
Time Lag ◽  
Vertical Direction ◽  
Visual Display ◽  
Hard Copy ◽  
Subjective Feeling ◽  
Visual Fatigue ◽  
Work Time ◽  
Mean Values ◽  
Significant Difference ◽  
The Mean

Visual fatigue caused by prolonged work viewing a Visual Display Terminals (VDT) and of work reading a hard-copy were assessed by electromyogram (EMG) waveform and electrooculogram (EOG) waveform in spontaneous blinks as objective criteria, and by questionnaire of subjective feeling, and by task performance. The duration and the amplitude of the EMG of the orbicularis ocular muscle on the right side and the EOG of the vertical direction to the eyelid were measured for 10 subjects who participated in a figure task consisting of the addition of single-digit numbers on a VDT work or a work with a hard-copy. The mean values of the duration and the amplitude of the EMG and the EOG were evaluated by the averaging of 10 waveforms of the spontaneous blinks for all subjects. The time lag from the EMG to the EOG in the process of the generation of spontaneous blinks was also analyzed. These five parameters were evaluated during the work time. The mean values for the duration of the EMG increased gradually during the work time, but the amplitude did not show significant difference between the prework and a work time. There was no significant change of the duration of the EOG, but the mean amplitude of the EOG decreased as the work time progressed, and the time lag significantly extended. The blinks frequency increased relatively when using a VDT. The rate of fluctuation for these parameters was higher during use of a VDT than use of a hard-copy. The time lag at five hours of VDT work was extended by 90% based on the value at the prework. The symptoms of general fatigue and fatigue of the eyes increased linearly during the VDT work for six hours. The results indicated a significant correlation between the objective parameters for the activity of the spontaneous blinks, i.e., duration and amplitude of EMG and EOG, and the time lag between EMG and EOG, and the subjective feeling was recognized in the time course of the task. These experimental results suggested that the parameters regarding the EMG and the EOG for the spontaneous blinks were effective indices for assessing visual fatigue during prolonged VDT work.

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