scholarly journals Influence of expiration date on detail reproduction of dental elastomers

2021 ◽  
Vol 10 (11) ◽  
pp. e306101118837
Author(s):  
Ricardo Danil Guiraldo ◽  
Eric Yudi Harada ◽  
Sandrine Bittencourt Berger ◽  
Flaviana Alves Dias ◽  
Danielle Gregorio ◽  
...  
Keyword(s):  
Metal Matrix ◽  
Descriptive Analysis ◽  
Three Dimensional ◽  
Expiration Date ◽  
Impression Material ◽  
Synthetic Rubber ◽  
Impression Materials ◽  
Dimensional Network ◽  
Cross Links ◽  
Surface Detail

Elastomers are synthetic rubber materials formed by polymers, which are joined by a small number of cross-links that form a three-dimensional network. The aim of the current study was to compare the surface detail reproduction of polyvinyl siloxane and polyether-based elastomeric impression materials (2 years after their expiration date) to the ones that have not exceeded this period-of-time. Four groups comprising 5 samples, each (n = 5), were divided based on material (polyvinyl siloxane – Express and polyether – Impregum Soft) and expiration date (expired, or not). The manipulated material was placed on a tray in a way to fully cover its inner part. Later on, it was placed on a metal matrix presenting 20-, 50- and 75-μm lines. Molds were removed after polymerization and surface detail reproduction was measured in comparator microscope (Stereozoom Microscope), along the 20 μm line (25 mm in length), at 4x-magnification, in compliance with ISO 4823. Surface detail reproduction values were subjected to descriptive analysis - results were expressed in percentage (%). All groups presented 100% of surface detail reproduction, regardless of impression material or expiration date. Surface detail reproduction of the investigated materials was not influenced by the evaluated elastomers’ expiration date.

scholarly journals Evaluation and Comparison of Dimensional Accuracy of Newly Introduced Elastomeric Impression Material using 3D Laser Scanners: An in vitro Study

2013 ◽  
Vol 14 (2) ◽  
pp. 265-268 ◽  
Author(s):  
Naveen S Yadav ◽  
Teerthesh Jain ◽  
Amrita Pandita ◽  
SMA Feroz ◽  
Pradeep LNU ◽  
...  
Keyword(s):  
Three Dimensional ◽  
Laser Scanner ◽  
In Vitro Study ◽  
Dimensional Accuracy ◽  
Time Intervals ◽  
Impression Material ◽  
Impression Materials ◽  
Laser Scanners ◽  
Master Model

ABSTRACT Aim Aim of the present study was to comparatively evaluate dimensional accuracy of newely introduced elastomeric impression material after repeated pours at different time intervals. Materials and methods In the present study a total of 20 (10 + 10) impressions of master model were made from vinyl polyether silicone and vinyl polysiloxane impression material. Each impression was repeatedly poured at 1, 24 hours and 14 days. Therefore, a total of 60 casts were obtained. Casts obtained were scanned with three-dimensional (3D) laser scanner and measurements were done. Results Vinyl polyether silicone produced overall undersized dies, with greatest change being 0.14% only after 14 days. Vinyl polysiloxane produced smaller dies after 1 and 24 hours and larger dies after 14 days, differing from master model by only 0.07% for the smallest die and to 0.02% for the largest die. Conclusion All the deviations measured from the master model with both the impression materials were within a clinically acceptable range. Clinical significance In a typical fixed prosthodontic treatment accuracy of prosthesis is critical as it determines the success, failure and the prognosis of treatment including abutments. This is mainly dependent upon fit of prosthesis which in turn is dependent on dimensional accuracy of dies, poured from elastomeric impressions. How to cite this article Pandita A, Jain T, Yadav NS, Feroz SMA, Pradeep, Diwedi A. Evaluation and Comparison of Dimensional Accuracy of Newly Introduced Elastomeric Impression Material using 3D Laser Scanners: An in vitro Study. J Contemp Dent Pract 2013;14(2):265-268.

scholarly journals A Comparative Study on Accuracy and Reproducibility of Alginate and Addition Reaction Silicone as an Impression Materials.

2014 ◽  
Vol 3 (2) ◽  
pp. 28-33
Author(s):  
Shakila Fatema ◽  
Sheikh Md Shahriar Quader ◽  
Mohammad Shamsuzzaman ◽  
Mirza Md Arifur Rahman ◽  
Nasima Khan
Keyword(s):  
Addition Reaction ◽  
In Vitro Study ◽  
Dimensional Accuracy ◽  
Horizontal Line ◽  
Impression Material ◽  
Dimensional Changes ◽  
Impression Materials ◽  
Study Results ◽  
Surface Detail

Background: To achieve accuracy and exact reproduction of prosthesis, choosing a perfect impression material is essential. Especially to make the prosthesis as accurately as possible, impression material should possess some essential properties, like; minimum dimensional changes, good flow ability and easy removal. Purpose: The aim of this study was to evaluate the accuracy and surface detail reproduction of Alginate and Addition Reaction Silicone as an impression materials. Method: This is an experimental in vitro study. In this study Impression by Alginate and Addition Reaction Silicone were made using a round stainless steel test block with three horizontal lines and two vertical lines. The horizontal lines were used for evaluating the surface detail reproduction, and vertical lines were provided for the dimensional accuracy. For dimensional accuracy the length of the middle horizontal line in between vertical lines and the distance between the top and bottom horizontal line was measured using travelling microscope. And for surface detail reproduction three horizontal line of one segment were observed under stereomicroscope. Result: According to study results Addition Reaction Silicone is better than Alginate regarding quality of impression. Conclusion: In comparison to Alginate, Addition Reaction Silicone might have better performance about accuracy and surface detail reproduction. DOI: http://dx.doi.org/10.3329/updcj.v3i2.17996 Update Dent. Coll. j: 2013; 3 (2): 28-33

“EVALUATION OF SURFACE DETAIL REPRODUCTION OF BD IMPRESS AND NEXUS MEDODENT THERMOPLASTIC IMPRESSION MATERIALS” - AN IN VITRO COMPARATIVE STUDY

2021 ◽  
pp. 28-30
Author(s):  
Ajay Balaji ◽  
Naveen .B.H ◽  
Kalavthi. S.D ◽  
arun Thomas Philip
Keyword(s):  
Comparative Study ◽  
Dimensional Stability ◽  
P Value ◽  
Thermoplastic Material ◽  
Impression Material ◽  
Good Surface ◽  
Impression Materials ◽  
Surface Detail ◽  
Essential Prerequisite

Impression making is the primary step in the process of fabrication of prosthetic restoration. Dimensional stability, Surface detail reproduction, and compatibility with gypsum products is an essential prerequisite for a successful restoration. Clinically, the accuracy of impressions depends on two major aspects: 1) Ability to ow and adapt intimately to the relevant surfaces while making the impression, and 2) the wetting of the polymerized impression material by the gypsum. The purpose of this study is to evaluate and compare the surface detail reproduction of BD Impress and Nexus Medodent impression material. The results showed signicant difference in surface detail between the two thermoplastic impression materials with p-value <0.05. It was observed that comparison of mean scores obtained by BD Impress and Nexus Medodent impression material are 2.7556 and 2.2222 respectively. The materials with minimum mean score value is considered as the material with good surface detail reproduction. Thus one can conclude that Nexus Medodent thermoplastic material has the good surface detail reproduction compared to BD Impress thermoplastic material.

scholarly journals The Polymer Binders for the Electrodes of Lithium Batteries Part 2. Synthetic and Natural Polymers

2020 ◽  
Vol 20 (4) ◽  
pp. 175-205
Author(s):  
Aigul S. Istomina ◽  
◽  
Olga V. Bushkova ◽  
Keyword(s):  
Three Dimensional ◽  
Synthetic Polymers ◽  
Water Soluble ◽  
Self Healing ◽  
Composite Electrodes ◽  
Natural Polymers ◽  
Power Characteristics ◽  
Polymer Binders ◽  
Dimensional Network ◽  
Cross Links

The second part of the review describes the prospects of using alternative polymer binders for composite electrodes of lithium electrochemical systems. Possible options having been taken into account, the most popular commercially-available synthetic polymers with functional group (the ones forming aqueous solutions or dispersions predominantly) and water-soluble polymers of natural origin are considered. The versatility of such materials is their distinctive feature. The availability of salt forms for natural and synthetic polymers, many of which are polyelectrolytes, makes it possible to significantly affect the ion transfer in the composite electrode mass, reducing the polarization of the electrodes and improving the power characteristics of batteries. The ability to form “artificial SEI” and / or form a three-dimensional network with self-healing cross-links between macromolecules allows long-term safe cycling, the latter being especially important for active materials with very large volume changes during lithium intercalation / deintercalation (e.g. silicon).

scholarly journals The influence of handling on the elasticity of addition silicone putties

2003 ◽  
Vol 17 (3) ◽  
pp. 254-260 ◽  
Author(s):  
Leonardo Eloy Rodrigues Filho ◽  
Antonio Muench ◽  
Carlos Francci ◽  
Angelika Katia Luebke ◽  
Andréia Aparecida Traina
Keyword(s):  
Natural Rubber ◽  
Cross Contamination ◽  
Impression Material ◽  
Contamination Control ◽  
Latex Gloves ◽  
Synthetic Rubber ◽  
Satisfactory Performance ◽  
Impression Materials

The handling of vinyl polysiloxane (addition silicone) impression putties with latex gloves is said to interfere with the setting of these impression materials. The aim of this study is to evaluate the effect of handling techniques on the setting of vinyl polysiloxane impression putties using several types of gloves. The setting of these materials was evaluated by means of an elasticimeter. Four vinyl polysiloxane putty impression materials and five brands of gloves (one made of vinyl, one of synthetic rubber, and three of natural rubber) were studied. Based on the type of glove, they were previously washed or not, and a spatula was used or not for initial mixing (before handmixing). The vinyl, the synthetic and one of the natural rubber gloves did not require the previous washing procedure and/or the use of a spatula for initial mixing. Two other natural rubber gloves - depending on the silicone -, showed satisfactory results only when the initial mixing was performed with a spatula. It was concluded that setting inhibition depends on the kind of vinyl polysiloxane impression material and the kind of gloves used, but when the initial mixing was performed with the spatula this setting inhibition was overcome. The results of this study also showed that it is possible to associate cross-contamination control and satisfactory performance of addition silicone putty materials. When doubts arise from the compatibility between vinyl polysiloxane impression putties and gloves, the initial mixing should be performed with a spatula.

VULCANIZATION OF RUBBER COMPOUNDS WITH PEROXIDE CURING SYSTEMS

2017 ◽  
Vol 90 (1) ◽  
pp. 60-88 ◽  
Author(s):  
Ján Kruželák ◽  
Richard Sýkora ◽  
Ivan Hudec
Keyword(s):  
Three Dimensional ◽  
Rubber Matrix ◽  
Cross Linking ◽  
Rubber Compounds ◽  
Dimensional Network ◽  
Fundamental Goal ◽  
Cross Links ◽  
Curing Agents ◽  
Curing Systems

ABSTRACT Vulcanization or curing is one of the most important processes in rubber technologies. During this process, plastic rubber compounds by parallel and subsequent physical and mainly chemical reactions change into highly elastic products—vulcanizates. The fundamental goal of curing is forming chemical cross-links between rubber macromolecules, which leads to the formation of a three-dimensional network or rubber matrix. A number of curing systems have been introduced in cross-linking of elastomers; each system has its own characteristics and composition; therefore, vulcanizates with different properties also can be prepared. We characterize organic peroxides as curing agents and their decomposition mechanisms and characteristics and bring a detailed view to understanding mechanisms between peroxides and different types of rubber matrices. Then, we focus on the classification and characterization of co-agents used in peroxide cross-linking and explain the mutual interactions and reaction mechanisms between peroxide, co-agents, and rubber matrices in relation to the properties of prepared materials. Finally, the drawbacks and the main features of final cross-linked materials are outlined.

Drawing of Piezoceramic Fibers and Ribbons Using a Novel Alginate Gelation Method and Properties of Fiber and Ribbon-Based Piezodevices

2012 ◽  
Vol 445 ◽  
pp. 380-385 ◽  
Author(s):  
Sedat Alkoy ◽  
A. Serkan Tekdas ◽  
Emre Tekel ◽  
Recep Olukkent
Keyword(s):  
Lead Zirconate Titanate ◽  
Piezoelectric Ceramic ◽  
Structural Characteristics ◽  
Slip Casting ◽  
Three Dimensional ◽  
Lead Zirconate ◽  
Ceramic Fibers ◽  
Dimensional Network ◽  
Dry Pressing ◽  
Cross Links

Piezoceramics are usually shaped into three dimensional bulk form using dry pressing or slip casting methods. However, certain applications require piezoceramics to be shaped in one dimensional fiber or two dimensional ribbon form. In this study, piezoceramic fibers and curved piezoceramic ribbons were fabricated using a novel alginate gelation method. Alginate is a natural linear polymer that is obtained from brown kelp. In the presence of multivalent cations, it forms ionic cross-links and gels in a three dimensional network form. In our study, gelation conditions of alginate containing aqueous slips of lead zirconate titanate based piezoelectric ceramic powders were investigated. Piezoelectric ceramic fibers and ceramic ribbons were prepared by sintering of gelled powders for transducer applications. Structural characteristics of these ceramics and electrical characteristics of piezodevices prepared from these ceramics were investigated and reported.

Development of Mucoadhesive Buccal Drug Delivery System of Propranolol Hydrochloride Using Aster ericoides Mucilage

2020 ◽  
Vol 10 (2) ◽  
pp. 133-148
Author(s):  
Ankaj Kaundal ◽  
Pravin Kumar ◽  
Rajendra Awasthi ◽  
Giriraj T. Kulkarni
Keyword(s):  
Buccal Cavity ◽  
Three Dimensional ◽  
Hot Water ◽  
Fickian Diffusion ◽  
Aster Ericoides ◽  
Dimensional Network ◽  
Buccal Tablet ◽  
Significant Difference ◽  
Volunteer Group

Aim: The study was aimed to develop mucoadhesive buccal tablets using Aster ericoides leaves mucilage. Background : Mucilages are naturally occurring high-molecular-weight polyuronides, which have been extensively studied for their application in different pharmaceutical dosage forms. Objective: The objective of the present research was to establish the mucilage isolated from the leaves of Aster ericoides as an excipient for the formulation of the mucoadhesive buccal tablet. Method: The mucilage was isolated from the leaves of Aster ericoides by maceration, precipitated with acetone and characterized. Tablets were prepared using wet granulation technique and evaluated for various official tests. Results: The mucilage was found to be non-toxic on A-431 and Vero cell lines. It was insoluble but swellable in cold and hot water. The results indicate that mucilage can form a three-dimensional network. The pH of the mucilage (6.82 ± 0.13) indicated that it might be non-irritant to the buccal cavity. The mucilage was found to be free from microbes. The release of drug was by Fickian diffusion. The in vivo buccal tablet acceptance was 80%. No significant difference between the diastolic blood pressure of standard and Aster tablets treated volunteer group was recorded. Conclusion: The mucilage was found to be non-toxic on A-431 and Vero cell lines. It was insoluble but swellable in cold and hot water. The results indicate that mucilage can form a three-dimensional network. The pH of the mucilage (6.82 ± 0.13) indicated that it might be non-irritant to the buccal cavity. The mucilage was found to be free from microbes. The release of drug was by Fickian diffusion. The in vivo buccal tablet acceptance was 80%. No significant difference between the diastolic blood pressure of standard and Aster tablets treated volunteer group was recorded. Other: However, to prove the potency of the polymer, in vivo bioavailability studies in human volunteers are needed along with chronic toxicity studies in suitable animal models.

Sign in / Sign up

Export Citation Format

Share Document