scholarly journals Effect of Water Dilution on Full-Arch Gypsum Implant Master Casts

Prosthesis ◽  
2020 ◽  
Vol 2 (4) ◽  
pp. 266-276
Author(s):  
James L. Sheets ◽  
Alvin G. Wee ◽  
Bobby Simetich ◽  
Mark W. Beatty
Keyword(s):  
Compressive Strength ◽  
Physical Properties ◽  
Knoop Hardness ◽  
Compressive Modulus ◽  
Type Iii ◽  
Type Iv ◽  
Excess Water ◽  
Type V ◽  
Linear Setting ◽  
Water Dilution

The objective of this study was to assess if the setting expansion, compressive strength, compressive modulus and Knoop hardness is reduced in Type III, IV and V gypsum products when excess water is added to recommended water/powder (W/P) ratios for full-arch implant master casts. Four properties were measured: linear setting expansion, compressive strength, compressive modulus, and Knoop hardness. Three dental stones were evaluated: ISO Type III, Type IV, and Type V. Water was added to recommended W/P ratios as follows: (1) 0%, the manufacturer’s recommend W/P ratio, (2) 50%, 1.5 times the manufacturer’s recommendation of water, (3) 100%, three times the manufacturer’s recommendation of water, (4) 150%, 2.5 times the manufacturer’s recommendation of water, and (5) 200%, three times the manufacturer’s recommendation of water. For all three gypsum types, 50% water additions minimally affected the setting expansion and compressive modulus (p > 0.05), but lowered compressive strength by 26% to 52% (p < 0.05). Knoop hardness was lowered by 24% and 48% for Types V and III (p < 0.05), whereas Type IV was not significantly affected (p > 0.05). With few exceptions, the physical properties for the three gypsum types reached minimum values at 100% dilution, with few changes noted at higher dilutions. Increased W/P ratios did not adequately reduce the setting expansion and adversely affected other physical properties. Of the gypsums tested, Type IV is still recommended due to its lower setting expansion for full-arch implant master casts.

Linear setting expansion of different gypsum products

RSBO ◽  
2016 ◽  
Vol 12 (1) ◽  
pp. 61
Author(s):  
Adilson Yoshio Furuse ◽  
César Antunes de Freitas ◽  
Tatiana Sanches Zanotti ◽  
Fabio Antonio Piola Rizzante ◽  
Márcia Furtado Antunes de Freitas
Keyword(s):  
Linear Expansion ◽  
Dental Practice ◽  
Type Ii ◽  
Restorative Material ◽  
Measuring Device ◽  
Type Iii ◽  
Type Iv ◽  
Type V ◽  
Linear Setting ◽  
Water Ratio

Introduction: Stone casts are used in dentistry to allow the confection of indirect restorations. Thus, gypsum dimensional stability is fundamental in order to achieve a precise fit between dental structure and restorative material. Objective: The purpose of the present study was to evaluate the hygroscopic linear expansion of commercially available gypsum products. Material and methods: Fifteen dental stones were analyzed (4 type II, 5 type III, 4 type IV and 2 type V), with n = 5. One hundred grams of each gypsum product were mixed following the respective manufacturers’ recommendations for powder/water ratio and poured into a V-shape mold, connected to an expansion-measuring device. The hygroscopic expansion was evaluated during 120 min and the collected data was converted into percentage and compared to initial dimensions of the specimen. Results: All type II and V dental stones showed expansion values compatible to the ADA and ISO recommendations. Considering type III stones, only Rutenium 3 was compatible with the recommendations. For type IV, only Durone IV showed expansion values higher than that recommended by ADA, but lower than that of ISO recommendations. Conclusion: The hygroscopic linear expansion of gypsum products should be periodically controlled in order to ensure their precision and reliability to dental practice.

Syntheses of Post-Iboga Alkaloids

Synthesis ◽  
2019 ◽  
Vol 51 (14) ◽  
pp. 2737-2758 ◽  
Author(s):  
Hyeonggeun Lim ◽  
Sikwang Seong ◽  
Sunkyu Han
Keyword(s):  
Secondary Metabolites ◽  
Type I ◽  
Type Ii ◽  
Type Iii ◽  
Type Iv ◽  
Synthetic Studies ◽  
Type V

Post-iboga alkaloids are secondary metabolites that are biosynthetically derived from iboga-type alkaloids via rearrangements of the indole and/or isoquinuclidine moieties. Herein, we categorize post-iboga alkaloids into five types based on the biosynthetic mode of transformation of the iboga scaffold. We then describe reported syntheses of post-iboga alkaloids, including our laboratory’s recent contributions, based on our own categorization.1 Introduction1.1 Iboga and Post-Iboga Alkaloids1.2 Classification of Post-Iboga Alkaloids1.2.1 Introduction to Type I Post-Iboga Alkaloids1.2.2 Introduction to Type II Post-Iboga Alkaloids1.2.3 Introduction to Type III Post-Iboga Alkaloids1.2.4 Introduction to Type IV Post-Iboga Alkaloids1.2.5 Introduction to Type V Post-Iboga Alkaloids2 Syntheses of Post-Iboga Alkaloids2.1 Syntheses of Type I Post-Iboga Alkaloids2.1.1 Syntheses of Monomeric Type I Post-Iboga Alkaloids2.1.2 Syntheses of Dimeric Type I Post-Iboga Alkaloids2.2 Syntheses of Type II Post-Iboga Alkaloids2.3 Synthetic Studies Toward Type III Post-Iboga Alkaloids2.4 Syntheses of Type IV Post-Iboga Alkaloids2.5 Synthesis of Type V Post-Iboga Alkaloids3 Conclusion and Outlook

Phosphodiesterase isozymes modulating inherent tone in human airways: identification and characterization

1993 ◽  
Vol 264 (5) ◽  
pp. L458-L464 ◽  
Author(s):  
K. F. Rabe ◽  
H. Tenor ◽  
G. Dent ◽  
C. Schudt ◽  
S. Liebig ◽  
...  
Keyword(s):  
Particulate Phase ◽  
Cyclic Monophosphate ◽  
Type Iii ◽  
Peripheral Airways ◽  
Type Iv ◽  
Pde Inhibitors ◽  
Biochemical Studies ◽  
Human Airways ◽  
Type V ◽  
Identification And Characterization

The effects of the nonselective phosphodiesterase (PDE)-inhibitor 3-isobutyl-1-methylxanthine (IBMX) and the selective PDE inhibitors SKF 94120 (type III), rolipram (type IV), zardaverine (type III/IV), and zaprinast (type V) on inherent tone in human airways were investigated. Substantial relaxation was achieved by IBMX [concentration eliciting 50% of maximum response (EC50): 2.9 microM, n = 14] and SKF 94120 (EC50: 1.4 microM, n = 15); rolipram and zaprinast were almost ineffective. Zardaverine (EC50: 0.31 microM, n = 8), and the combination of SKF 94120 and rolipram (1 microM; EC50: 0.41 microM) were effective relaxants. Biochemical studies revealed the presence of PDE isozymes I, III, IV, and V in the cytosolic and particulate phase of airway homogenates, whereas PDE II was present only in the cytosol. Partial inhibition of total PDE adenosine 3',5'-cyclic monophosphate-hydrolyzing activity was achieved with rolipram and a selective type III inhibitor, whereas there was almost complete inhibition of total PDE activity with either zardaverine or the combination of type III and IV inhibitors. We conclude that all five PDE isozyme families are present in crude preparations of human peripheral airways. Inherent tone in this tissue is most effectively relaxed through selective type III/IV PDE inhibitors.

scholarly journals Study On The Application of Preoperative Three-Dimensional CT Angiography of Perigastric Arteries In Laparoscopic Radical Gastrectomy

2022 ◽  
Author(s):  
Peng Liu ◽  
Wenbin Yu ◽  
Meng Wei ◽  
Danping Sun ◽  
Xin Zhong ◽  
...  
Keyword(s):  
Gastric Cancer ◽  
Blood Loss ◽  
Three Dimensional ◽  
Classification Model ◽  
Type I ◽  
Radical Gastrectomy ◽  
Type Ii ◽  
Type Iii ◽  
Type Iv ◽  
Type V

Abstract Objection: To investigate the clinical value and significance of preoperative three-dimensional computerized tomography angiography (CTA) in laparoscopic radical gastrectomy for gastric cancer.Methods: The clinical data were analyzed retrospectively from 214 gastric cancer patients. We grouped according to whether to perform CTA. The gastric peripheral artery was classified according to CTA images of patients in the CTA group, and we compared and analyzed the difference of the data between the two groups.Results: The celiac trunk was classified according to Adachi classification: Type I (118/125, 94.4%),Type II (3/125, 2.4%),Type III (0/125, 0%),Type IV (1/125, 0.8%),Type V (2/125, 1.6%),Type VI (1/125, 0.8%).Hepatic artery classification was performed according to Hiatt classification standard:Type I (102/125, 81.6％),Type II (9/125, 7.2%),Type III (6/125, 4.8%),Type IV (2/125, 1.6%),Type V (3/125, 2.4%),Type VI (0, 0%),Others (3/125, 2.4%).And this study combined vascular anatomy and clinical surgical risk to establish a new splenic artery classification model. It was found that the operation time and estimated blood loss in the CTA group were significantly lower than those in the non-CTA group. In addition, the blood loss in the CTA group combined with ICG (Indocyanine Green) labeled fluorescence laparoscopy was significantly less than that in the group without ICG labeled. Conclusion: Preoperative CTA can objectively evaluate the vascular course and variation of patients, and then avoid the risk of operation, especially in combination with ICG labeled fluorescence laparoscopy, can further improve the quality of operation.

A Review and Proposed Classification System for the No-Option Patient With Chronic Limb-Threatening Ischemia

2020 ◽  
pp. 152660282096391
Author(s):  
Tanner I. Kim ◽  
Shant S. Vartanian ◽  
Peter A. Schneider
Keyword(s):  
Treatment Strategies ◽  
Major Amputation ◽  
Occlusive Disease ◽  
Tissue Loss ◽  
Type I ◽  
Type Ii ◽  
Type Iii ◽  
Type Iv ◽  
Foot Anatomy ◽  
Type V

A growing, but poorly defined subset of patients with chronic limb-threatening ischemia (CLTI) have “no option” for revascularization. One notable subgroup includes patients with severe ischemia and advanced pedal artery occlusive disease, termed “desert foot,” who are at high risk for major amputation due to a lack of conventional revascularization options. Although new therapies are being developed for no-option patients with desert foot anatomy, this subgroup and the broader group of no-option patients are not well defined, limiting the ability to evaluate outcomes. Based on a systematic review, a classification of the no-option CLTI patient was constructed for use in clinical practice and studies. Several no-option conditions were identified, including type I—severe and pedal occlusive disease (desert foot anatomy) for which there is no accepted method of repair; type II—lack of suitable venous conduit for bypass in the setting of an acceptable target for bypass; type III—extensive tissue loss with exposure of vital structures that renders salvage impossible; type IV—advanced medical comorbidities for which available revascularization options would pose a prohibitive risk; and type V—presence of a nonfunctional limb. While type I and type II patients may have no option for revascularization, type III and type V patients have wounds, infection, comorbidities, or functional status that may leave them with few options for revascularization. As treatment strategies continue to evolve and novel methods of revascularization are developed, the ability to identify no-option patients in a standardized fashion will aid in treatment selection and assessment of outcomes.

Antimicrobial Activity of Type III Dental Gypsum Incorporated with 3-iodo-2-propynyl-butylcarbamate and its Physical Properties

2014 ◽  
Vol 1052 ◽  
pp. 322-326 ◽  
Author(s):  
Sroisiri Thaweboon ◽  
Passiri Nisalak ◽  
Boonyanit Thaweboon ◽  
Pornrachanee Sawaengkit ◽  
Plang Ngern Saksit ◽  
...  
Keyword(s):  
Antimicrobial Activity ◽  
Compressive Strength ◽  
Physical Properties ◽  
Setting Time ◽  
Brain Heart Infusion ◽  
Antimicrobial Activities ◽  
Microbial Reduction ◽  
Type Iii ◽  
Time Type ◽  
Infusion Agar

Dental impressions have been considered to be potential sources of microbial contamination from patients’ blood and saliva to dental personnel and prostheses fabricated on gypsum casts. Thus, the development of dental gypsum with antimicrobial activity to reduce cross-contamination between patients and laboratory personnel is needed. This study aims to evaluate the influence of incorporation of 3-iodo-2-propynyl-butylcarbamate (IPBC) into type III dental gypsum on its antimicrobial activities and physical properties such as dry compressive strength and setting time. Type III dental gypsum (The Siam Moulding Plaster Co., Ltd, Thailand) incorporated with 3 concentrations of IPBC (0.01%, 0.005% and 0.001% w/w) was tested compared with the control, gypsum without disinfectant. Microorganisms tested were Staphylococcus aureus ATCC 6538, Pseudomonas aeruginosa ATCC 27853 and Candida albicans ATCC 1023. One hundred μL of each microbial suspension (108 CFU/mL) was dropped on hydrocolloid impression (Jeltrate; Caulk/Dentsply, Milford, DE) and left dry. All types of gypsum mixes were prepared and poured into the impressions and allowed to set for 60 min. Then the gypsum samples were removed and the microbial contact surfaces were imprinted on Brain Heart Infusion agar plates. After incubation, colonies appeared on agar were gram-stained and counted. The dry compressive strength and setting time were tested in accordance with International Standard (ISO) 6873: 1998 (E). Dental gypsum containing IPBC showed antimicrobial activity against all tested microorganisms with the percentage of microbial reduction ranging from 19.4% to 70.6%. Among all types of dental gypsum, no significant differences in dry compressive strength and setting time were observed. The newly developed type III dental gypsum incorporated with IPBC had antimicrobial effects against all tested microorganisms. The physical properties of the modified dental gypsum were within the ISO standards. However, further investigation on other properties such as dimensional stability, detail reproduction and clinical usage are still needed.

scholarly journals Abrasion resistance of high early-strength concrete for rapid repair

2019 ◽  
Vol 289 ◽  
pp. 02002
Author(s):  
Nader Ghafoori ◽  
Matthew O. Maler ◽  
Meysam Najimi ◽  
Ariful Hasnat
Keyword(s):  
Compressive Strength ◽  
Abrasion Resistance ◽  
Wear Test ◽  
Cement Concrete ◽  
Rapid Repair ◽  
Strength Concrete ◽  
Type Iii ◽  
Resistance To Wear ◽  
Early Strength ◽  
Type V

This paper examines the abrasion resistance of high early-strength concrete developed for rapid repair of highways and bridge decks. The cement types chosen for this study included ASTM Type III, ASTM Type V, and Calcium Sulfoaluminate (CSA) cements. A cement content of 386 kg/m3 (650 lb/yd3) was maintained for all studied concretes. Test samples were tested after 24 hours and 28 days of curing in order to evaluate compressive strength and depth of wear. Test results revealed that the opening time to attain minimum required compressive strength for CSA cement concrete was one hour, whereas the values for Type V and Type III cement concretes were 8.5 and 6 hours, respectively. After 24 hours curing, CSA cement concrete displayed the highest strength, but lowest resistance to wear. The 28-day cured CSA cement concrete produced the highest strength and resistance to abrasion, while Type III cement concrete showed a similar strength, but lower resistance to wear, when compared to those of the Type V cement concrete.

scholarly journals Properties of high early-strength Type V cement concrete for rapid repair

2019 ◽  
Vol 289 ◽  
pp. 02003
Author(s):  
Nader Ghafoori ◽  
Matthew O. Maler ◽  
Meysam Najimi ◽  
Ariful Hasnat
Keyword(s):  
Compressive Strength ◽  
Strength Properties ◽  
Experimental Program ◽  
Cement Concrete ◽  
Freezing And Thawing ◽  
Rapid Repair ◽  
Type Iii ◽  
Chloride Migration ◽  
Early Strength ◽  
Type V

This study examines the suitability of ASTM Type V cement concrete for rapid repair applications. To this end, experimental results on transport and durability properties of high early-strength concretes using ASTM Type V cement were compared with those of a more traditional cement used for rapid repair, i.e. Type III cement. A cement content of 445 kg/m3 (750 lb/yd3) was maintained for all studied concretes. The experimental program included compressive strength, absorption, rapid chloride migration, corrosion resistance, and mass loss due to freezing and thawing regimes. The results of this study revealed that use of Type III and V cements were both effective for concrete rapid repair applications. The opening time to reach the minimum compressive strength of 21 MPa (3000 psi) was found dissimilar. Type III cement concrete showed better strength properties at early ages due to its high fineness. However, as curing age was extended to 24 hours and 28 days, Type V cement concrete produced higher strength results. Moreover, Type III cement concretes failed to display better performance in transport properties, corrosion, and frost resistance when compared to that of the studied Type V cement concretes.

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