Volumetric Change as a Parameter for the Accuracy of Impression Materials

Author(s):  
Mihaela Păpușa Vasiliu ◽  
Liliana Sachelarie ◽  
Carmen Stadoleanu ◽  
Cătălina Gîrbea ◽  
Agripina Zaharia

In this paper we studied the behavior of some impression materials such as alginate, condensation and addition silicones, considering the following parameters: the reproductive capacity of morphological details - dimensional stability - the ability to reproduce with accuracy the ratio between morphological elements. The essential conditions that an impression material should fulfill are plasticity, fidelity, flexibility, good mechanical strength, dimensional stability, suitable setting time and compatibility with materials from which the models are manufactured.The study results indicated that condensation silicones present the highest volumetric changes, their contraction being the result of the evaporation of volatile byproducts.The dimensional stability of fingerprint materials is one of the variables that contribute to the accuracy or inaccuracy of dental prostheses, other factors being represented by the changes occurring during the preparation of the fingerprint material as well as the fingerprinting techniques.

2011 ◽  
Vol 12 (4) ◽  
pp. 272-278 ◽  
Author(s):  
Dheeraj Kumar ◽  
Anand U Madihalli ◽  
K Rajeev Kumar Reddy ◽  
Namrataa Rastogi ◽  
NT Pradeep

ABSTRACT Aim The aim of the present study is to compare the various elastomeric impression materials in terms of accuracy and dimensional stability, with respect to obtaining multiple casts from a single elastomeric impression at various times of pours. Materials and methods Three master dies were prepared for the impression making, two of these were made of brass containing a central hole with undercuts. The third die simulated a conventionally prepared typodont maxillary central incisor. Three elastomeric impression materials were chosen for the study. Each impression was poured at various time periods. Casts thus obtained were evaluated under a traveling microscope to evaluate various dimensional changes. Results Addition silicones provided dies which were shorter in height and bigger in diameter. Polyethers provided dies which were shorter in both height and diameter. Condensation silicones showed insignificant changes from the master die at the immediate pour but deteriorated rapidly after that in subsequent pours. Conclusion None of the impression material showed a consistent behavior up to the fourth pour. They occasionally showed deviation from the pattern, but all these values were statistically insignificant. Polyethers showed lesser ability than both the addition silicones as well as the condensation silicones to recover from induced deformation. Clinical significance Addition silicones as well as the condensation silicones have better ability to recover from induced deformation when compared to polyether. How to cite this article Kumar D, Madihalli AU, Reddy KRK, Rastogi N, Pradeep NT. Elastomeric Impression Materials: A Comparison of Accuracy of Multiple Pours. J Contemp Dent Pract 2011;12(4):272-278.


PRILOZI ◽  
2017 ◽  
Vol 38 (2) ◽  
pp. 131-138 ◽  
Author(s):  
Borjan Naumovski ◽  
Biljana Kapushevska

Abstract A quality-made dental impression is a prerequisite for successful fixed-prosthodontic fabrication and is directly dependent on the dimensional stability, accuracy and flexibility of the elastomeric impression materials, as well as on the appropriately used impression techniques. The purpose of this paper is to provide a literature review of relevant scientific papers which discuss the use of various silicone impression materials, different impression techniques and to evaluate their impact on the dimensional stability and accuracy of the obtained impressions. Scientific papers and studies were selected according to the materials used, the sample size, impression technique, storage time, type of measurements and use of spacer for the period between 2002 and 2016. In the reviewed literature several factors that influence the dimensional stability and accuracy of silicone impression molds, including the choice of the type of viscosity, impression material thickness, impression technique, retention of the impression material on the tray, storage time before the casting, number of castings, hydrophilicity of the material, release of byproducts, contraction after polymerization, thermal contraction and incomplete elastic recovery were presented. The literature review confirmed the lack of standardization of methodologies applied in the research and their great diversity. All findings point to the superiority of the addition silicone compared to the condensation silicone.


2014 ◽  
Vol 3 (2) ◽  
pp. 28-33
Author(s):  
Shakila Fatema ◽  
Sheikh Md Shahriar Quader ◽  
Mohammad Shamsuzzaman ◽  
Mirza Md Arifur Rahman ◽  
Nasima Khan

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


2021 ◽  
pp. 28-30
Author(s):  
Ajay Balaji ◽  
Naveen .B.H ◽  
Kalavthi. S.D ◽  
arun Thomas Philip

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.


2018 ◽  
Vol 63 (01) ◽  
pp. 55-61
Author(s):  
Borjan Naumovski ◽  
Jadranka Bundevska ◽  
Biljana Kapusevska

The diverse viscosities of silicone impression materials are suited for their use in various impression techniques, intended to improve the precision of the cast impression in the form of a plaster model. The purpose of this research is to determine the dimensional stability and accuracy of the double-phase impression technique in 1 step and 2 steps by using a condensation silicone impression material. This research was carried out by using a precise stainless-steel master model and an individual aluminum tray. Comparing the abutments of the master model and the abutments of the double-phase impression technique in 2 steps, showed that they are wider on average 81 µm, while the abutments from the double-phase impression technique in 1 step are on average 281 µm wider in diameter. After analyzing the results obtained in relation to the diameter of the abutments, it can be concluded that the double-phase impression technique in 2 steps is dimensionally more stable and accurate compared to the double-phase impression technique in 1 step. This study shows that dimensional stability and accuracy of impression materials also depend on the selection of appropriate impression technique and proper performance in order to obtain a high quality dental impression that will be the basis for an accurate fixed-prosthodontic fabrication. Keywords: silicone impression material, impression technique, fixed partial dentures, dimensional stability and accuracy


2021 ◽  
pp. 22-25
Author(s):  
Arun Thomas Philip ◽  
Kalavthi. S.D ◽  
Naveen. B.H ◽  
Ajay Balaji

Aim: To evaluate and compare the linear dimensional stability of two commercially available BD IMPRESS and NEXUS MEDODENT thermoplastic impression materials. A total of 90 samples in which 45 s Methodology: amples of BD Impress and Nexus medodent impession materials were used for evaluation of linear dimensional stability of these newly introduced thermoplastic impression materials. The samples were rst checked under toolmaker microscope for reproduction of three parallel lines x,y,z. The measurements were made on the samples at 0 (within 24 hours), 7th and 14th day respectively to assess the linear dimensional stability. According to the study conducted and results obtained, it Result: was concluded that NEXUS MEDODENT was superior in linear dimensional stability on comparison with BD IMPRESS impression material Conclusion: On comparison with BD impress, nexus medodent impression material was superior in terms of linear dimensional stability. There is a need for further studies to know about other properties of these thermoplastic impression materials to enhance knowledge and for clinical application as indicated by manufacturers.


2021 ◽  
Vol 15 (1) ◽  
pp. 658-663
Author(s):  
Noorhayati R. Mohd ◽  
Ros A. Omar ◽  
Enas A. Etajuri

Aims: This study aimed to evaluate and compare the dimensional stability of two elastomeric impression materials, namely polyvinyl siloxane (PVS) and vinyl siloxanether (VSE), subjected to chemical immersion and microwave irradiation for disinfection. Materials and Methods: Sixty discs of PVS and VSE impression materials each were prepared using a stainless-steel test die and ring in accordance with ANSI/ADA Specification No. 19. Twenty discs of each impression material were disinfected by chemical immersion for 10 min; another 20 discs were subjected to dry microwave irradiation for 3 min. The other 20 discs served as a control group. Dimensional stability measurements were then performed using an image analyzer at 20× magnification. The data were analyzed by one-way analysis of variance (α=0.05) and Bonferroni (post hoc) test for multiple comparisons to detect significant differences between the groups. Results: When subjected to microwave irradiation, both PVS and VSE showed dimensional changes, but the changes were within the limit of 1.5% set by ANSI/ADA (P<0.00). VSE showed markedly better results than PVS for both disinfection methods. The immersion disinfection method resulted in a higher average percentage of linear dimensional changes than both the microwave irradiation and the control for VSE and PVS impression materials. Conclusion: VSE exhibited excellent dimensional stability than PVS under both chemical immersion and microwave irradiation. Microwave irradiation using conventional microwave ovens can be used in clinical settings as an alternative to other disinfection techniques because the dimensional changes of the elastomeric impression materials subjected to microwave irradiation have been observed to be within the clinically acceptable limit set by the ANSI/ADA standard.


Marine Drugs ◽  
2022 ◽  
Vol 20 (1) ◽  
pp. 55
Author(s):  
Nurlindah Hamrun ◽  
Bahruddin Talib ◽  
Muhammad Ruslin ◽  
Hasminar Pangeran ◽  
Mochammad Hatta ◽  
...  

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.


2020 ◽  
Vol 147 ◽  
pp. 03015
Author(s):  
Ellya Sinurat ◽  
Subaryono ◽  
Anantaria Okawati Rambe

This study was aimed to prepare dental impression material from Sargassum duplicatum taken from Binuangeun, Banten. The setting time was tested according to ANSI/ADA Specification for Alginate Impression Materials 1983. After extraction, obtained the alginate powder then mixed its water/powder ratio from the combination of alginate composition and tested final setting time. Variations of the formulations used different calcium sulfate (0,1 g; 0,2 g; and 0,3 g). Product quality parameters are lumps, solubility, consistency, flow, tearing, setting time. The alginate yield obtained from Sargassum duplicatum by 31 % with characteristic gel strength by 816 (gr/cm2); viscosity 238 mPas (2%; room temperature). The highest ratio is the best ratio by adding calcium sulfate powder of 0.1 gram with a setting time of 3 minutes.


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