Two-step Impression Technique Research Articles

Is a Wiggling-Motion Modified Two-Step Impression Technique as Accurate as Conventional Techniques in Restorative Dentistry?

The purpose of this study was to evaluate dental impression accuracy of one-step and two-step techniques compared to a modified two-step technique. Four impression techniques were compared: (1) a one-step double mix (DM) technique, (2) a cut-out (CO) technique, in which space relief was created using a blade and a laboratory bur, (3) a membrane (ME) technique, in which space relief was created by placing a PVC membrane on top of the putty material during the primary impression, and (4) a wiggling motion (WI) technique, in which PVC membrane was placed and additional wiggling movements were performed during the first 20 s when the primary impression was seated upon the master model (MM). Impressions were poured with type IV stone. Casts were scanned with a laboratory scanner and measurements were made for each cast using three-dimensional analysis software. All groups presented differences compared to MM group, in at least one intra-abutment distance. Groups DM and ME presented the most significant differences, in three and two distances, respectively, whereas CO and WI presented one significant different distance compared to MM. There were no differences between MM and the four techniques for inter-abutment distances. WI yielded similar results with CO technique. Both performed better than the other groups.

Evaluation of One- and Two-Step Impression Techniques and Vertical Marginal Misfit in Fixed Prothesis.

12 impressions were made of a resin maxillary model (second premolar and second molar) with two prepared abutment teeth using vinyl polysiloxane (VPS); the margin of the second premolar was 0.5 mm subgingivally; and the margin of the second molar tooth was at the level of the gingiva. Impressions were made using two techniques: one-step and two-step putty/light materials. A three-unit metal framework was fabricated on the master model using the computer-aided design/computer-aided manufacturing (CAD/CAM) technique. The vertical marginal misfit was evaluated in the buccal, lingual, and mesial and distal surfaces of the abutments on the gypsum casts using a light microscope. Data were analyzed using the independent t-test (α < 0.05). The results showed significantly lower vertical marginal misfit in all six areas evaluated around the two abutments in the two-step impression technique compared with the corresponding values in the one-step technique. Vertical marginal misfit in the two-step technique with a preliminary putty impression was significantly lower than in the one-step putty/light-body technique.

The Effects of Abutment Finish Lines on the Penetration Characteristics of Elastomers into the Simulated Gingival Sulcus.

The aim of this study was to determine the effect of finish lines on the penetration ability of polyether and polyvinyl siloxane impression material into the simulated gingival sulcus. Three types of finish line (chamfer, deep chamfer, and radial shoulder) were impressed with two types of elastomeric impression material (polyether and polyvinyl siloxane) using a two-step impression technique. Ten samples of each finish line were prepared and then separated into two groups of impression material: polyether and polyvinyl siloxane. The model of the simulated gingival sulcus had a width of 0.1 mm and a depth of 3.5 mm with a subgingival finish line of 0.5 mm. The effect of the finish lines on the penetration ability of these impression materials was analyzed using a two-way analysis of variance (ANOVA) and Tukey's multiple comparison tests at a statistically significant level of 0.05. A two-way ANOVA revealed a significant difference among finish lines, impression materials, and their interaction. The deep chamfer and radial shoulder finish lines displayed significantly higher penetration ability than the chamfer finish line. Moreover, polyether revealed significantly higher penetration ability than polyvinyl siloxane. The finish lines affected the penetration ability of the impression materials. Therefore, the simulated gingival sulcus model demonstrates that it is an effective way of examining impression materials' penetration abilities.

Comparison of Linear Dimensional Accuracy Between One Step and Two-step Impression Technique Using Polyvinyl Siloxane Impression Material

Objectives: This study compares the linear dimensional accuracy between one step and two-step impression techniques using polyvinyl siloxane impression material. Methodology: The Randomized controlled trial was done in the Department of Prosthodontics, FMH College of Medicine and Dentistry Lahore and Pakistan Council for Science and Industrial Research Lahore. All impression samples which fall under the inclusion criteria in the Department of Prosthodontics, FMH College of Medicine and Dentistry Lahore and Pakistan Council for Science and Industrial Research Lahore were included. Samples were divided into two groups, i.e., Group 1 (single-step technique) &amp; Group 2 (two-step technique). The impression's longitudinal length and inter-line distance were measured to assess the outcome i-e linear dimensional accuracy. Result: A total of 60 impression samples with polyvinyl siloxane impressions material were made. The linear dimensional accuracy in one step &amp; two-step impression technique was seen in 5 (8.33%) &amp; 13(21.66%) samples, respectively, (p=0.011). Conclusion: Compared to the one-step impression technique, the higher linear dimensional accuracy of the two-step impression technique uses polyvinyl siloxane impression material.

COMPARATIVE EVALUATION OF THE DIMENSIONAL ACCURACY OF ONE-STEP VERSUS TWO STEP PUTTY WASH IMPRESSION TECHNIQUES USING TWO DIFFERENT COMMERCIALLY AVAILABLE ADDITION SILICONE ELASTOMERIC IMPRESSION MATERIALS – AN In-vitro STUDY

Introduction: An exact impression of dental and dentoalveolar structures is a significant and fundamental prerequisite for the exact fixture of the prosthesis. The advancement of the prosthesis with respect to fit, accuracy, and long life are dependent upon the impression materials, the strategies utilized, and the duration of time of pouring the impression.&#x0D; Aim: Compare and Evaluate the Dimensional Accuracy of One-Step versus Two-Step Putty Wash Impression Techniques Using Two Different Commercially Available Addition Silicone Elastomeric Impression Materials.&#x0D; Methodology: Impressions were made of a metal die having reference lines on it, by one-step wash impression technique and two-step impression technique. After making the impression, impression was allowed to set for 1 hour and then poured in Zhermack die stone. Die stone was allowed to set. Stone dies were obtained from each group. Metal die and stone dies from each group were assessed under stereo microscope 10x zoom using reference lines.&#x0D; Results: When compared to a one-step putty wash impression approach, a two-step putty wash impression process was more reliable. Comparing Virtual (Ivoclar Vivadent, USA) addition polyvinyl siloxane impression material to Aquasil (Dentsply, Germany), it was discovered that it was more accurate. Based on the findings, it has been determined that Ivoclar Vivadent Virtual addition silicone is more precise than Zhermack Aquasil addition silicone and that two-step putty wash impression method is more accurate than one-step putty wash impression method.&#x0D; Conclusion: Inside impediments of this study the following outcomes were drawn that two-stage clay wash impression method is more precise when contrasted with one stage clay wash impression strategy with a spacer of 1 mm for light body consistency expansion polyvinyl siloxane impression material. And The Ivoclar Vivadent Virtual expansion polyvinyl impression material showed more exactness when contrasted with Zhermack Aquasil expansion polyvinyl impression material utilizing one stage and two-stage clay wash impression strategies.

Dimensional accuracy of three impression materials by one-step and two-step impression techniques: An in vitro study

Introduction: An accurate impression is essential to create a well-fitted dental prosthesis. This study aimed to compare the dimensional accuracy of three elastomeric materials using one-step and two-step impression techniques. Methods: In this study, 20 impressions were fabricated for each Vinyl siloxane ether (Identium), condensation silicone (Speedex), and additional silicone (Panasil) impression materials by the one-step and two-step impression techniques using perforated metal trays. The one-step impression technique was simultaneously performed with heavy body/light-body materials. In the two-step impression technique, acrylic copings with 2-mm thickness were placed on the abutments to obtain similar spacing for the light-body material. The dimensional accuracy of different impression materials and techniques were measured using distance differences of the stone dies from the master cast; subsequently, the results were compared with the reference model. Data were analyzed using a one-way analysis of variance and Dunnett’s tests (α=0.05). Results: All impression materials demonstrated an acceptable clinical accuracy. Identium (Vinyl siloxane ether) displayed the most accuracy in both the one-step and two-step impression techniques (P>0.05). The best accuracy for Panasil (additional silicone) was found to be the two-step impression technique (P>0.05), and the best accuracy for Speedex (condensation silicone) was reported as the one-step impression technique (P>0.05). Furthermore, the one-step impression technique was highly accurate in diameter dimension, as compared to the two-step impression technique. Conclusion: As evidenced by the results, the accuracy of impression is affected by the impression materials. Moreover, Identium (Vinyl siloxane ether) demonstrated the most accuracy in both one-step and two-step impression techniques.

Dimensional Accuracy of Working Dies Fabricated by Different Impression Materials and Techniques: 3D Digital Assessment

Accuracy of dental impression plays a significant role in the success of definitive restorations. This study aimed to compare the dimensional accuracy of working dies fabricated using two different impression materials and techniques. Forty working dies fabricated from 40 impressions of preprepared mandibular first molar tooth replica stabilized in a jaw model to receive full coverage crown. Two different Polyvinyl siloxane (PVS) impression materials were used; Aquasil and Virtual. Two different impression techniques were used with each type of impression material; One-step and two-step. The working dies dimensional accuracy was measured in four dimensions and compared with that of the preprepared molar tooth replica using a digital caliper and 3D scanner. Based on a 3D scanner, there were a significant difference of dies fabricated by the two tested impression materials using the two-step impression technique in Mesiodistal-Gingival dimension (IIA and IIB) groups compared to the preprepared tooth replica with an average 0.370 μm (P &lt; .005). A significant difference was observed of the dies fabricated by the two tested impression techniques using virtual impression. material in Mesiodistal Occlusal dimensions with an average 0.135 μm (P &lt; .03), and in Mesiodistal-Gingival dimensions with an average 0.490 μm (P &lt; .001) and Buccolingual-Gingival dimensions with an average 0.143 μm (P &lt; .005) using Aquasil impression material compared to the preprepared molar tooth replica. Both impression materials (Aquasil and Virtual) and techniques (One-step and Two-step) used in this study produced working dies with clinically accepted dimensional accuracy.

Kvalitet zubnog otiska dva različita brenda polivinil siloksan impresionih materijala

Background: This study was to evaluate the impression quality and clinical success of 2 Polyvinyl siloxane (PVS) impression materials by using dual-viscosity 1-step impression technique and the putty-wash two-step impression technique. Methods: In this study, Variotime (Heraeus, Hanau, Germany) and a novel silicone Spirias (Imicryl, Konya, Turkey) were selected as PVS impression materials. A total of 40 samples were divided into groups according to the impression technique. Three possible categories were established to rate the impression quality. The impression was examined using a laboratory microscope (Opmi Pico, Zeiss) and lenses with 2X to 6X magnification for the presence or absence of bubbles or voids and the complete reproduction of the preparation finish line. A spreadsheet (Excel v2016; Microsoft Corp) was used for processing statistical data. Results of the analysis were calculated as mean and frequency. Results: In the impressions taken with Variotime, the percentage of the successful impression is 95% (Criteria I - II). Only one impression was found unacceptable (criteria III). In impressions with Spirias, the percentage of successful impressions is 100% (Criteria I - II). No impression was found unacceptable (criterion III). Conclusion: The quality of impressions of both brands Polyvinyl siloxane impression materials revealed a high rate (97.5%) For more precise results, many new studies were needed on different Polyvinyl siloxane impression materials.

One-step versus two-step impression techniques; a literature review

ObjectiveThe aim of this literature review was to compare one-step impression technique versus two-step impression technique regarding their dimensional accuracy. MethodologyA Medline search was conducted through PubMed and Saudi Digital Library search engine using the following terms “impression techniques”, “conventional techniques”, “one-step”, “two-step” and “accuracy”. The search reviewed between 2008 and 20018. Twenty-nine articles were screened. Nine articles were assessed for eligibility out of which six were included. ResultsThree articles found that one-step impression technique had better dimensional accuracy than two-step impression technique. While the other articles showed that two-step impression technique had better dimensional accuracy than one-step impression technique. ConclusionWithin the limitations of this review, both one-step and two-step impression techniques exhibited acceptable dimensional accuracy. There are still controversies about the accuracy of one-step impression technique versus that of two-step impression technique, so more extensive in-vivo clinical studies should be performed.

Comparison of Dimensional Accuracy of Stone Models Fabricated by Three Different Impression Techniques Using Two Brands of Polyvinyl Siloxane Impression Materials

The aim of this study is to check the dimensional precision of stone models made by two different brands of polyvinyl siloxane impression materials using the monophase, one-step, and two-step putty/light-body impression techniques. A metal model, having two crown preparations, was fabricated. With each technique, 40 impressions were made using two types of polyvinyl siloxane impression materials (Aquasil and Virtual). A total of 240 impressions were made with both the polyvinyl siloxane impression materials. Monophase impressions were made with a medium body using an acrylic custom tray. By simultaneous usage of putty and light-body, one-step impressions were made with a perforated metal stock tray. For two-step impressions, a 25-40 microns thick cellophane sheet spacer was used. The stone casts were obtained from the impressions of the stainless steel model. Three different dimensions (height, diameter, and inter-abutment distance) on these resultant stone casts were compared with the standard die. The accuracy of two different brands of impression materials was also compared. The results were then statistically analyzed. The resultant casts obtained from the different impression techniques had significantly larger dimensions in height and diameter, but smaller dimensions were observed for the inter-abutment distance. Larger deviation in resultant casts was observed in the monophase than one-step impression technique and the least deviation was observed in the two-step impression technique. The two-step impression technique produced the most accurate results in terms of the resultant casts. Out of the two different brands, Aquasil produced more fare results. Adequate marginal adaptation, proper fit and least distortion of the castings, and the final prosthesis can be achieved by using the adequate impression technique and impression material.

One- versus two-step impression techniques

One- versus two-step impression techniques

Simplified Prosthetic Rehabilitation of a Patient after Oral Cancer Removal.

The treatment of patients with oral cancer is complex: a multidisciplinary approach needs to be taken and maxillofacial and oral surgeons, an oncologist, a prosthodontist should be included, and a psychologist is often needed. This case report describes the prosthetic rehabilitation of a patient after surgical removal of oral cancer with obturator prosthesis. Resection cavity was located in central part of the hard palate and the condition belonged to Aramany class 3 maxillary defects. The two-step impression technique of denture bearing area was used and the resection of cavity was performed. A primary impression-the impression of denture bearing area was made using irreversible hydrocolloid material, while the second impression - the impression of resection cavity was made using condensation silicone material and obturator prosthesis framework. The obturator prosthesis replaced lost teeth, improved oral function and esthetics at minimal costs.

Dimensional Accuracy of Multiple Pour Cast from Different Elastomer Impression Techniques

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 &lt;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.

Two step impression technique for implant restorations

Two-step (spacer used with the putty impression first and then the wash stage) impression technique is commonly used for making impressions in conventional fixed dental prosthesis. Impressions for implant fixed restorations are usually taken in 1-step. This article describes two-step impression technique for the implant fixed restorations. With the 2-step putty-wash impression technique described in this article, pressure developed on the impression analogues is negligible hence more accuracy and less deformation can be achieved.

The effect of one-step vs. two-step impression techniques on long-term accuracy and dimensional stability when the finish line is within the gingival sulcular area

All the polyvinyl siloxane impression materials tested met acceptable linear dimensional characteristics as defined by ADA specification.

A two-step (altered cast) impression technique in the prosthetic rehabilitation of a patient after a maxillectomy: A clinical report

This clinical report describes the prosthetic rehabilitation complicated by trismus (as a consequence of surgery and radiation therapy) of a patient with an acquired maxillary defect, after surgical removal of the right maxillary sinus tumor. The patient was restored with a partial removable dental prosthesis with a hollow bulb obturator to obtain orofacial rehabilitation and defect obturation. Precise obturation requires an accurate impression of the resection defect. A 2-step impression was performed because of trismus. A primary maxillary impression was made with an irreversible hydrocolloid, while a secondary (altered cast) impression was made with a silicone material by using the obturator cast framework as a tray. In that way an altered cast was produced. Subsequently, an obturator prosthesis was processed with a conventional technique.

The Effect of One‐Step vs. Two‐Step Impression Techniques on Long‐Term Accuracy and Dimensional Stability when the Finish Line is within the Gingival Sulcular Area

To evaluate the effect of two putty-wash impression techniques on the long-term accuracy and dimensional stability of poly(vinyl siloxane) (PVS) in the gingival sulcus area. Impressions were taken from a master cast to simulate molar crown preparation. A space around the abutment served as the gingival sulcus. Fifteen impressions using the one- and two-step impression techniques were taken using Express Regular, Express Fast, and President impression materials with custom trays. Using a Toolmaker's microscope, the long (LD) and short distances (SD) of the abutment and the planar distance between two parallel lines (PL) at the circumference of the cast were taken at 0.5, 2, 24, 48, 72, 96, 120, and 144 hours after mixing. ANOVA was performed, with the discrepancy between the distances of the impressions and the master cast as the dependent variable. The differences when different materials and impression techniques were used were significant (p < 0.001) for LD, SD, and PL, as was the interaction between the material, time, and technique (p < 0.001). SD discrepancies were higher than those of LD for all materials and times. The two-step impression technique was more accurate, with smaller discrepancies than the one-step impression technique. For all materials, the PL discrepancy was deemed acceptable (less than 0.5%) for all tested times. President had higher discrepancies than the other materials. When using the two-step putty-wash impression technique, pouring of the impressions may be postponed up to 30 hours; however, when using the one-step impression technique, pouring should be performed within 2 hours.

Effect of Various Putty-Wash Impression Techniques on Marginal Fit of Cast Crowns

Marginal fit is an important clinical factor that affects restoration longevity. The accuracy of three polyvinyl siloxane putty-wash impression techniques was compared by marginal fit assessment using the nondestructive method. A stainless steel master cast containing three abutments with three metal crowns matching the three preparations was used to make 45 impressions: group A = single-step technique (putty and wash impression materials used simultaneously), group B = two-step technique with a 2-mm relief (putty as a preliminary impression to create a 2-mm wash space followed by the wash stage), and group C = two-step technique with a polyethylene spacer (plastic spacer used with the putty impression followed by the wash stage). Accuracy was assessed using a toolmaker microscope to measure and compare the marginal gaps between each crown and finish line on the duplicated stone casts. Each abutment was further measured at the mesial, buccal, and distal aspects. One-way analysis of variance was used for statistical analysis. P values and Scheffe post hoc contrasts were calculated. Significance was determined at .05. One-way analysis of variance showed significant differences among the three impression techniques in all three abutments and at all three locations (P < .001). Group B yielded dies with minimal gaps compared to groups A and C. The two-step impression technique with 2-mm relief was the most accurate regarding the crucial clinical factor of marginal fit.

An Evaluation of Dimensional Accuracy of One-Step and Two-Step Impression Technique Using Addition Silicone Impression Material: An In Vitro Study

The study is aimed to evaluate the dimensional accuracy, the effect of undercut of two different configurations and the elastic recovery of addition silicone impression material assessed indirectly, by measuring the dimensions on stone models recorded from the impression of the master model, using one-step and two-step impression technique, for addition silicone impression materials. Measurements are taken to evaluate horizontal or linear and vertical dimensional changes, of the abutment V and abutment C from the stainless steel model. Heavy body/light body material is used for making one-step impression technique in a custom tray. Putty/light body is used for taking two-step technique in a stock metal tray. Improved die stone is used for pouring the impression. The different 11 locations on the dies produced by two different techniques are measured microscopically on image analyzer and compared with those of stainless steel model. Anova test was applied to test the differences of mean values of inter and intra abutment measurements, to calculate p value. Unpaired t test was applied to calculate t value. Results showed less deviation of stone models produced by one-step technique from stainless steel model, whereas the deviation of stone models produced by two-step is comparatively more. (p<0.01). This difference of deviation is significantly less in one-step as compared to two-step technique. One-step is sufficiently dimensionally accurate than two-step technique in conjunction with addition silicone impression material. They have the best elastic recovery from the two undercut configurations.

Comparative Analysis of Dimensional Precision of Different Silicone Impression Materials

To investigate the accuracy of four commercial types of additional silicone impression materials (AFFINIS®, Virtual®, Relay 2002 CD® and Silagum®). The accuracy of impression material was measured indirectly by measuring three dimensions on stone cast poured from impressions of a stainless steel master model. The three dimensions on stone cast were measured at 1 hour, 2 days, 1 and 2 weeks after making the impression. Two impression techniques were used in the current study. The two-step impression technique was used for AFFINIS® and Virtual®, while single-step technique was used for Relay 2002 CD® and Silagum® materials. Twenty impressions were made of the master cast at four different periods for each of the tested four materials with a total of 320 impressions. Two vertical dimensions and one horizontal dimension were measured on master cast using optical microscope. Statistical analysis was run to compare the mean measurements for tested casts from each impression and time interval with the master cast. No statistical significant differences were found (p > 0.05) in the accuracy of tested materials. There was no significant difference of master cast and impression cast means over time. Additionally, impression technique could be correlated with accuracy. The tested additional silicones showed accuracy over time and they could be delayed up to 4 weeks duration without any significant changes in its dimensional stability. Silagum® impression material was the most accurate followed by Relay 2002 CD®, Virtual® and AFFINIS®. Silagum® impression material is most accurate followed by Relay 2002 CD®, Virtual® and AFFINIS®.