A Comparison of Dimensional Accuracy of Addition Silicone of Different Consistencies with Two Different Spacer Designs - In-vitro Study

Rathee, Suprabha; Eswaran, B; Eswaran, MA; Prabhu, R; N, Geetha K; Krishna, G Phani; Jagadeshwari,

doi:10.7860/jcdr/2014/9139.4585

Cited by 13 publications

(8 citation statements)

References 40 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…Two spacers were used for molding, one only covering the die and the other covering the die and the toothless gap. The authors concluded that the impression method, in which the spacer covered the die and the toothless gap simultaneously was more accurate [16]. The results of this study have not been consistent with ours.…”

Section: Discussioncontrasting

confidence: 84%

Effects of different impression methods and holding times on the dimensional accuracy of addition silicones

Mahboubi¹,

Mollai²,

Rahbar³

2020

jos

View full text Add to dashboard Cite

Introduction: Dimensional stability of dies is very important in the success of fixed prosthodontics treatments. Impression methods and holding time are the most important factors affecting dimensional stability of the dies. Objectives: This study was performed to investigate the effects of three impression methods and four different dies holding times on the dimensional variations of dies. Material and methods: In this in vitro study, 144 gypsum samples were obtained from an in vitro model in the form of prepared pillars of a long bridge-one pyramid dies, with occlusal diameter of 9.43 mm and height of 12.84 mm, and the other with occlusal diameter of 12.84 mm and height of 12.80 mm. Two dies distance was 44.20 mm. Forty-eight samples were prepared by one-stage molding, 48 samples by two-stage impression with a spacer on the dies and toothless space, and 48 samples by the two-stage impression and with a spacer on the dies. Each of these three groups was divided into four 12-membered subgroups (1 h, 24 h, 48 h, and one week). Dimensional accuracy of the samples was evaluated by a digital caliper and micrometer. To analyze the data, two-way ANOVA test was used (p < 0.05). Results: The mean of diameter, the height of smaller die, and the distance between the two dies was 9.50 ± 0.01, 12.89 ± 0.02, and 44.26 ± 0.01 mm, respectively, in the one-stage impression; 9.46 ± 0.01, 12.87 ± 0.01, and 44.22 ± 0.01 mm, respectively, in the two-stage impression with spacer on the dies; and 9.46 ± 0.01, 12.87 ± 0.01, and 44.22 ± 0.01 mm, respectively, in the two-stage impression with spacer on the dies and toothless space. There was a significant difference between one-stage and two-stage impression methods (p < 0.05), but there was no significant difference between two two-stage impression methods (with different spacer types). Regarding different holding times, no significant difference between them was observed (p > 0.05). Conclusions: The two-stage impression can result in higher dimensional accuracy than the one-stage impression method. Also, when additional silicones are used, the impression can be postponed by one week without significant dimensional changes in the final cast.

show abstract

Section: Discussioncontrasting

confidence: 84%

Effects of different impression methods and holding times on the dimensional accuracy of addition silicones

Mahboubi¹,

Mollai²,

Rahbar³

2020

jos

View full text Add to dashboard Cite

show abstract

“…The silicone with evenly distributed layer covers the impression surface, penetrating into the undermined areas and adheres well to the tray after the polymerization. Most important is however the fact that in the evenly distributed layer with a moderate thickness the total value of the permanent deformations in the silicones is insignificant [31,34].…”

Section: Discussionmentioning

confidence: 99%

Dimensional Stability and Accuracy of Silicone – Based Impression Materials Using Different Impression Techniques – A Literature Review

Naumovski

Kapushevska

2017

Prilozi

View full text Add to dashboard Cite

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.

show abstract

“…Most in vitro studies focusing on the accuracy of impressions used simplified master models with 1 to 3 truncated cone-shaped metal forms to simulate abutment teeth with full crown preparations. 18 19 20 24 25 26 27 28 29 Such idealistic and highly standardized settings facilitated a perfectly controlled space for the wash material. Their ability to reproduce the clinical situation were, however, limited due to missing undercuts and interproximal areas, and the documented accuracy was potentially overrated.…”

Section: Discussionmentioning

confidence: 99%

Accuracy of a separating foil impression using a novel polyolefin foil compared to a custom tray and a stock tray technique

et al. 2017

View full text Add to dashboard Cite

PURPOSETo compare the dimensional accuracy of three impression techniques- a separating foil impression, a custom tray impression, and a stock tray impression.MATERIALS AND METHODSA machined mandibular complete-arch metal model with special modifications served as a master cast. Three different impression techniques (n = 6 in each group) were performed with addition-cured silicon materials: i) putty-wash technique with a prefabricated metal tray (MET) using putty and regular body, ii) single-phase impression with custom tray (CUS) using regular body material, and iii) two-stage technique with stock metal tray (SEP) using putty with a separating foil and regular body material. All impressions were poured with epoxy resin. Six different distances (four intra-abutment and two inter-abutment distances) were gauged on the metal master model and on the casts with a microscope in combination with calibrated measuring software. The differences of the evaluated distances between the reference and the three test groups were calculated and expressed as mean (± SD). Additionally, the 95% confidence intervals were calculated and significant differences between the experimental groups were assumed when confidence intervals did not overlap.RESULTSDimensional changes compared to reference values varied between -74.01 and 32.57 µm (MET), -78.86 and 30.84 (CUS), and between -92.20 and 30.98 (SEP). For the intra-abutment distances, no significant differences among the experimental groups were detected. CUS showed a significantly higher dimensional accuracy for the inter-abutment distances with -0.02 and -0.08 percentage deviation compared to MET and SEP.CONCLUSIONThe separation foil technique is a simple alternative to the custom tray technique for single tooth restorations, while limitations may exist for extended restorations with multiple abutment teeth.

show abstract

A Comparison of Dimensional Accuracy of Addition Silicone of Different Consistencies with Two Different Spacer Designs - In-vitro Study

Cited by 13 publications

References 40 publications

Effects of different impression methods and holding times on the dimensional accuracy of addition silicones

Effects of different impression methods and holding times on the dimensional accuracy of addition silicones

Dimensional Stability and Accuracy of Silicone – Based Impression Materials Using Different Impression Techniques – A Literature Review

Accuracy of a separating foil impression using a novel polyolefin foil compared to a custom tray and a stock tray technique

Contact Info

Product

Resources

About