To Evaluate the Effect of Storage Temperature on the Linear Dimensional Accuracy of Delayed and Repeat Pours of Two Addition Silicone Impression Materials

Author(s):  
Manish Sen Kinra

Background: Addition silicone elastomers are the most commonly used impression materials for making final impression for fpd, implants and rpd. The dimensional stability and accuracy of addition silicone impression material are influenced by the storage time, temperature and repeat pour. Aim and Objectives: To evaluate the accuracy of two different types of addition silicone elastomeric impression materials, stored at a different temperature. To evaluate the accuracy of two different types of addition silicone elastomeric impression materials, after delayed and repeated pour. To compare the linear dimensions of two different types of addition silicone elastomeric impression materials with a control die. Materials and Methods: A machined standard steel master die and metal custom impression tray was made for making a final impression of machined standard steel master die. Final impression was made by using two different brands of addition silicone impression materials (Aquasil Ultra Impression material, Dentsply/ Caulk, Milford, D & 3M ESPE). Double step putty light body impression technique was used for making final impression. In this manner total numbers of 80 impressions were made and they were divided into two groups Group I and Group II. To study the effect of delayed pours and storage temperature were divided into 4 sub-groups, 10 impressions each. All the ten impressions of each sub groups were stored at 40°C in acrylizer, 24 hours at -10°C, 48 hours at -2°C and 1 week respectively at 0°C inside a refrigerator in a sealed plastic bags before been poured with type IV die stone. To study the effect of repeat pours on the accuracy of stone casts, all ten impressions of each sub groups was immediately re poured with type IV die stone after the removal of first set of casts. Thus again a fresh set of 80 cats were obtained having 40 casts belongs to each group. Results: When impressions were stored at 40°C in acrylizer, 24 hours at -10°C, 48 hours at -2°C and 1 week respectively at 0°C addition silicone impression materials did not show any significant change when compared to control samples. Conclusion: Both types of addition silicone elastomeric impression materials maintained their accuracy after delayed poured and repeat pours. Storing impressions under different conditions caused no adverse effect upon the accuracy of both types of addition silicone elastomeric impression materials. There was no significant change in the dimensions of stone casts obtained from both impression materials as compared to the dimensions of a master die. If addition silicone impression material is delayed pour up to 1 week, repeat pour and exposed from -10°C to 40°C in that clinical situation also linear dimensional accuracy will not be adversely effected.

Author(s):  
Satheesh B Haralur ◽  
Majed S Toman ◽  
Abdullah A Al-Shahrani ◽  
Abdullah A Al-Qarni

ABSTRACT Context The elastomeric impression material is the most widely used impression material in contemporary dental practice; their accuracy is critical for the outcome of indirect restorations. The accurate duplicate cast obtained from single impression reduces the professional clinical time, patient inconvenience, and extra material cost. Aim To compare the accuracy of the cast obtained from various impression methods utilizing elastomer impression materials. Materials and methods The stainless steel working cast model assembly consisting of two abutments and one pontic area was fabricated. Two sets of six each custom aluminum trays were fabricated, with 5 mm spacer and 2 mm space. The impression methods evaluated in the study were additional silicone putty reline (two step), heavy-light body (one step), monophase (one step), and polyether (one step). Type IV gypsum casts were poured at intervals of 1, 12, 24, and 48 hours. The resultant cast was measured with a traveling microscope for comparative dimensional accuracy. The data obtained were subjected to analysis of variance test at significance level <0.05. Results The die obtained from putty reline two-step impression techniques had the percentage of variation for the height -0.36 to -0.97% with 0.40 to 0.90% increase in diameter. One-step heavy-light body impression dies recorded the increased width by 0.50 to 0.80% and height reduced by - 0.73 to -1.21%. The resultant dies from additional silicone monophase impressions had a percentage of variation for width 1.20% and height by-1.34%. The similar value for width and height for polyether was -1.46% and -1.30% respectively. Conclusion Putty reline technique dies had better dimensional accuracy after repeated pour followed by dies from heavy-light body additional silicone impression. Key message The multiple pour cast from putty reline elastomeric impressions is clinically acceptable, while cast from polyether was smaller in dimension. How to cite this article Haralur SB, Toman MS, Al-Shahrani AA, Al-Qarni AA. Dimensional Accuracy of Multiple Pour Cast from Different Elastomer Impression Techniques. Int J Prosthodont Restor Dent 2016;6(3):51-56.


2017 ◽  
Vol 2017 ◽  
pp. 1-8 ◽  
Author(s):  
Sonam Gupta ◽  
Aparna Ichalangod Narayan ◽  
Dhanasekar Balakrishnan

Purpose. For a precise fit of multiple implant framework, having an accurate definitive cast is imperative. The present study evaluated dimensional accuracy of master casts obtained using different impression trays and materials with open tray impression technique.Materials and Methods. A machined aluminum reference model with four parallel implant analogues was fabricated. Forty implant level impressions were made. Eight groups (n=5) were tested using impression materials (polyether and vinylsiloxanether) and four types of impression trays, two being custom (self-cure acrylic and light cure acrylic) and two being stock (plastic and metal). The interimplant distances were measured on master casts using a coordinate measuring machine. The collected data was compared with a standard reference model and was statistically analyzed using two-way ANOVA.Results. Statistically significant difference (p<0.05) was found between the two impression materials. However, the difference seen was small (36 μm) irrespective of the tray type used. No significant difference (p>0.05) was observed between varied stock and custom trays.Conclusions. The polyether impression material proved to be more accurate than vinylsiloxanether impression material. The rigid nonperforated stock trays, both plastic and metal, could be an alternative for custom trays for multi-implant impressions when used with medium viscosity impression materials.


2013 ◽  
Vol 14 (2) ◽  
pp. 265-268 ◽  
Author(s):  
Naveen S Yadav ◽  
Teerthesh Jain ◽  
Amrita Pandita ◽  
SMA Feroz ◽  
Pradeep LNU ◽  
...  

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.


2013 ◽  
Vol 2 (1) ◽  
pp. 18-23 ◽  
Author(s):  
Daniela Araújo Veloso Popoff ◽  
Fabiana Santos Gonçalves ◽  
Wallace de Freitas Oliveira ◽  
Luiza Anjos Soares ◽  
Hugo Lemes Carlo ◽  
...  

ABSTRACT Background There are a great amount of materials and techniques to use during dental prosthesis production that may confuse the dentist at the time of choice. Material's choice should be done considering ideal chemicophysical and biological properties and high detail reproduction. Aims The present study aimed to test the influence of differents impression materials and storage times on the dimensional accuracy of casting models. Materials and methods Four elastomeric materials– polysulfide, polyether, condensation silicone and addition silicone–were used to reproduce a master model of human teeth which were prepared for metaloceramic fixed prosthodontics. Six reference points were established on each tooth in order to determine four intervals: MD–mesial-distal, BL–buccal-lingual and CO–cervical-occlusal distance from premolar, and INT– interpillar distance–from the distal surface of the premolar to the mesial surface of the molar. The impressions were stored for half, 2 and 12 hours and pondered with a type IV gypsum. Results Cast measurements data were subjected to ANOVA (4 × 3), Tukey's – α = 0.05, Kruskal-Wallis and Dunn's tests – α = 0.05. The interaction between materials and storage time presented statistically significant for VP and CO intervals. For each storage time, materials presented dimensional alteration statistically significant. Conclusion Impression materials accuracy was affected by the storage time. All materials presented different dimensional accuracy when evaluated in a same period of time. Polysulfide was the only material that presented stable behavior over the time. How to cite this article Gonçalves FS, de Freitas Oliveira W, Soares LA, Carlo HL, da Mota AS, Popoff DAV, Soares CJ. Impression Materials and Storage Time Influence on Cast Models Accuracy. Int J Experiment Dent Sci 2013;2(1):18-23.


2020 ◽  
Vol 12 (1) ◽  
pp. 7
Author(s):  
ManishSen Kinra ◽  
HindM Alghatam ◽  
AbrarAhmed Al Bin Al ◽  
RajashekharaBhari Sharanesha ◽  
PraveenKumar Khatri ◽  
...  

2019 ◽  
Vol 4 (2) ◽  
pp. 90-93
Author(s):  
Hussameldien Hussien ◽  
◽  
Natashekara Mallesh ◽  

Background of the study: Dental implants are one of the most sought-after choice of treatment for restoration and rehabilitation of missing teeth. However, the accuracy of the removable or fixed superstructures over the dental implants is influenced for a major proportion by the impression techniques and materials. This paper discusses the comparison of the accuracy of different impression materials and techniques used in the second stage of the dental implant treatment in vivo. Objective: The objective of the paper is to study the comparison of the accuracy of different impression materials and techniques used in the second stage of the dental implant’s treatment in vivo. Search methodology: Electronically key searched in scientific literature databases. Selection criteria: Based on the set inclusion and exclusion criteria such as studies conducted in partial edentulous arches, in the age group of 30 to 55 years. Data collection and analysis: A total of 248 literatures were found to be relevant to the framed topic and were scrutinised based on the dejected criteria and 18 kinds of literature obtained were taken into consideration. Main Result: Among the different impression materials taken into the comparative study, it was observed that polyvinyl siloxane exhibited a dimensional accuracy slightly greater than polyether. However, light body putty exhibited greater accuracy than medium body putty. Various impression techniques were compared to evaluate the dimensional accuracy of the impression. It was observed that the open tray technique and splinted impression technique produced a more dimensionally stable impression than the other techniques. Authors Conclusion: this study to assess the accuracy of various impression material and methods has concluded that while impression techniques influence the accuracy of the impression, the impression materials namely the Polyvinyl siloxane and polyether exhibit no significant difference with a slight preference to the polyvinyl siloxane. Hence the choice of impression material is at the discretion of the dentist performing the treatment and also this area requires further studies to establish conclusive evidence.


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


2012 ◽  
Vol 11 (4) ◽  
pp. 331-334
Author(s):  
Tariq Hasan Howlader ◽  
Mohammad Khursheed Alam ◽  
Alia Sultana

Background: Different types of impression materials and different procedures or methods have been introduced in Dentistry for preparing dowel crown.Materials and Methods: Injection technique with silicone impression materials are being extensively used by the materials to get an accurate impression. But whether this material neither ensures similar accuracy nor produces absolute accuracy. This study evaluate silicone impression material was efficient enough to produce nearest to actual intraradicular surface reproduction by assessing the void formation and dimensional accuracy.Conclusion: By assessing all the parameters the silicone impression material was proved to be the efficient for intraradicular surface reproduction. DOI: http://dx.doi.org/10.3329/bjms.v11i4.12614 Bangladesh Journal of Medical Science Vol. 11 No. 04 Oct’12  


1988 ◽  
Vol 32 (4) ◽  
pp. 860-863
Author(s):  
Goro Nishigawa ◽  
Kiwamu Ando ◽  
Masaki Inoue ◽  
Toru Ueyama ◽  
Kazuhiko Ogata ◽  
...  

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