scholarly journals Linear dimensional stability of irreversible hydrocolloids with and without disinfection at different storage times

RSBO ◽  
2018 ◽  
Vol 15 (2) ◽  
pp. 77-83
Author(s):  
Lidia Olga Bach Pinheiro ◽  
Alfonso Sanchez Ayala ◽  
Marcos Cezar Pomini ◽  
Vanessa Taborda da Cruz ◽  
Ingrid Viel del Farias ◽  
...  
Keyword(s):  
Stainless Steel ◽  
Dimensional Stability ◽  
Storage Time ◽  
Dental Practice ◽  
Type Iv ◽  
Significant Difference ◽  
Irreversible Hydrocolloid ◽  
Master Model ◽  
Storage Times ◽  
Digital Caliper

Irreversible hydrocolloids have been used in dental practice for decades and their pouring time has been suggested to be as short as possible; however the latest generation of alginates exhibit better properties, which could influence the fidelity of the casts. Objective: To evaluate the linear dimensional stability of stone casts obtained using two irreversible hydrocolloid brands (Cavex ColorChange and Jeltrate) after disinfection. Material and methods: Samples were divided into 16 groups (n = 10) according to brand, storage time and disinfection. Impressions were taken of a metallic master model made of stainless steel with two abutments. Cast models were obtained using type IV gypsum, after disinfection with sodium hypochlorite at 1% or without any disinfection followed by storage for four different times (immediate pouring, and after 24, 72 or 120 hours storage after obtaining the impressions) and the models were measured with a digital caliper. Data were submitted to ANOVA 3-way followed by Tukey’s test (α < 0.05). Results: A statistically significant difference was detected with Jeltrate Plus after 72 and 120 hours in storage (with and without disinfection), as well as Cavex without disinfection. Differences were found for Cavex with disinfection/24 hours storage, when compared to immediate pouring (P < 0.05). The alginates presented similar behavior regarding disinfection for the same time (P > 0.05). Conclusion: Storage longer than 24 hours affects the fidelity of casts. Disinfection does not promote significant alteration at any of the experimental times with either material.

scholarly journals Linear dimensional stability of irreversible hydrocolloids with and without disinfection at different storage times

RSBO ◽  
2019 ◽  
Vol 15 (2) ◽  
pp. 77
Author(s):  
Lidia Olga Bach Pinheiro ◽  
Alfonso Sanchez Ayala ◽  
Marcos Cezar Pomini ◽  
Vanessa Taborda da Cruz ◽  
Ingrid Viel del Farias ◽  
...  
Keyword(s):  
Stainless Steel ◽  
Dimensional Stability ◽  
Storage Time ◽  
Dental Practice ◽  
Type Iv ◽  
Significant Difference ◽  
Irreversible Hydrocolloid ◽  
Master Model ◽  
Storage Times ◽  
Digital Caliper

Irreversible hydrocolloids have been used in dental practice for decades and their pouring time has been suggested to be as short as possible; however the latest generation of alginates exhibit better properties, which could influence the fidelity of the casts. Objective: To evaluate the linear dimensional stability of stone casts obtained using two irreversible hydrocolloid brands (Cavex ColorChange and Jeltrate) after disinfection. Material and methods: Samples were divided into 16 groups (n = 10) according to brand, storage time and disinfection. Impressions were taken of a metallic master model made of stainless steel with two abutments. Cast models were obtained using type IV gypsum, after disinfection with sodium hypochlorite at 1% or without any disinfection followed by storage for four different times (immediate pouring, and after 24, 72 or 120 hours storage after obtaining the impressions) and the models were measured with a digital caliper. Data were submitted to ANOVA 3-way followed by Tukey’s test (α < 0.05). Results: A statistically significant difference was detected with Jeltrate Plus after 72 and 120 hours in storage (with and without disinfection), as well as Cavex without disinfection. Differences were found for Cavex with disinfection/24 hours storage, when compared to immediate pouring (P < 0.05). The alginates presented similar behavior regarding disinfection for the same time (P > 0.05). Conclusion: Storage longer than 24 hours affects the fidelity of casts. Disinfection does not promote significant alteration at any of the experimental times with either material.

scholarly journals The Effects of Custom Tray Material on the Accuracy of Master Casts

2008 ◽  
Vol 9 (6) ◽  
pp. 49-56 ◽  
Author(s):  
Ramin Mosharraf ◽  
Sina Shafa ◽  
Zeinab Zaree
Keyword(s):  
Stainless Steel ◽  
Visible Light ◽  
Polymethyl Methacrylate ◽  
Impression Material ◽  
Significant Difference ◽  
Irreversible Hydrocolloid ◽  
Light Curing ◽  
Master Model ◽  
Visible Light Curing ◽  
Digital Caliper

Aim In addition to the impression material, the type of impression tray influences the accurate dimensional transfer of the size and position of the teeth to the master cast. The aim of this study was to determine the accuracy of master casts produced from an alginate impression material using a visible-light-curing resin and autopolymerizing polymethyl methacrylate resin custom tray materials. Methods and Materials Two types of custom trays were fabricated from a stainless steel master model with three index studs. Twenty-two irreversible hydrocolloid impressions were made of the master model and then poured with a Type III dental stone. The distances between the reproduced index studs were measured to +/- 0.01 mm with a digital caliper. A one-way analysis of variance (ANOVA) and T-test were used for data analysis. Results There were no significant differences between the two tray materials for any of the three distances. There were no statistical differences between the master model and the casts made from the two tray materials in the length dimension, but there were significant differences in the vertical dimension. In terms of the width dimension there was a significant difference only between the cold curing group and the master model. Conclusion Within the limitations of this study, the dimensions of stone casts poured from an impression made using a light-cured tray did not differ significantly from those created from impressions made using autopolymerizing acrylic trays. However, working dies from the light-curing tray impressions were more accurate buccolingually than those from the autopolymerizing acrylic trays. Clinical Significance The accuracy of master cast reproduction using visible-light-curing resin or an autopolymerizing polymethyl methacrylate resin custom tray material is acceptable. Although autopolymerizing resin materials require less equipment and are relatively more inexpensive, light-cure tray materials may be the material of choice for custom tray fabrication due to greater accuracy in the buccolingual dimension. Citation Shafa S, Zaree Z, Mosharraf R. The Effects of Custom Tray Material on the Accuracy of Master Casts. J Contemp Dent Pract 2008 September; (9)6:049-056.

Effect of Storage Time on the Accuracy of Casts Made from Different Irreversible Hydrocolloids

2008 ◽  
Vol 9 (4) ◽  
pp. 59-66 ◽  
Author(s):  
Maurizio Sedda ◽  
Andrea Casarotto ◽  
Aune Raustia ◽  
Andrea Borracchini
Keyword(s):  
Relative Humidity ◽  
Dimensional Stability ◽  
Storage Time ◽  
Time Dependent ◽  
Special Device ◽  
Specific Storage ◽  
Tukey Test ◽  
Impression Materials ◽  
Irreversible Hydrocolloid ◽  
Master Model

Abstract Aim Several new irreversible hydrocolloid formulations have recently become available with claims of an improved dimensional stability by the manufacturers. The aim of this study was to evaluate the accuracy of casts made from alginate impression materials poured immediately and after specific storage periods. Methods and Materials Five alginates were tested: CA 37 (Cavex); Jeltrate (Dentsply Caulk); Jeltrate Plus (Dentsply Latin America); Hydrogum 5 (Zhermack); and Alginoplast (Heraeus Kulzer). A master model was mounted on a special device and used to obtain the impressions. These impressions were stored at 23°C and 100% relative humidity, then poured with gypsum immediately, and again after 24, 72 and 120 hours. The casts were measured and the data were analyzed by one way analysis of variance (ANOVA) and Tukey test at p<0.05. Results The dimensional stability of the alginate impressions was both material and time dependent (p<0.05). After 24 hours of storage, only Alginoplast and Hydrogum 5 comply with the master model (p>0.05). After 72 and 120 hours, only Hydrogum 5 was dimensionally stable (p>0.05). Conclusion The dimensional stability of the alginate impressions is influenced by the selected material and the storage time. Clinical Significance Alginate impressions should generally be poured immediately. However, some new types of alginate may have the pouring delayed. Citation Sedda M, Casarotto A, Raustia A, Borracchini A. Effect of Storage Time on the Accuracy of Casts Made from Different Irreversible Hydrocolloids. J Contemp Dent Pract 2008 May; (9)4:059-066.

scholarly journals Evaluation of the maladaptation of the test base in acrylic resin regarding the technique of preparation, place of measurement and storage time

2018 ◽  
Vol 47 (1) ◽  
pp. 51-56
Author(s):  
Natália Pereira de OLIVEIRA ◽  
Renata Pilli JÓIAS ◽  
Rodnei Dennis ROSSONI ◽  
Renato Morales JÓIAS
Keyword(s):  
Storage Time ◽  
Acrylic Resin ◽  
Hydraulic Press ◽  
Control Group ◽  
Preparation Technique ◽  
Test Base ◽  
Significant Difference ◽  
Storage Times ◽  
And Storage ◽  
Digital Caliper

Abstract Introduction The most used material for the preparation of the baseplates is the acrylic resin, but it can present distortions. Objective To evaluate preparation technique, region and storage time that presents less maladaptation of the base when made with self-cured acrylic resin. Material and method Models were created in gypsum type III simulating edentulous maxilla, as divided into 3 groups (n = 10): GC (control group) thermopolymerizable acrylic resin; G1 - manual adaptation technique and G2 - drip technique. For the measurements, silicone by condensation of light consistency that was interposed between base and model was used. With a hydraulic press, 50 kg pressure was applied leading the base of the model. The obtained mold was measured in the palate, canine and molar regions with a digital caliper at the following times: immediately after the base polymerization, at 24, 48, 72, 96 hours and one week. The results were submitted to statistical analysis. Result G1 presented maladaptation of 0.43 mm ± 0.10, while G2 obtained 0.39 mm ± 0.11. The lowest maladaptation occurred in the CG. The palate region presented greater maladaptation (0.52 ± 0.07) and the canine region, the lowest (CD = 0.27 mm ± 0.07 and CE = 0.27 ± 0.09); There was no statistically significant difference for storage times. Conclusion G2 presented lower values than G1, with no statistically significant difference. The palate region presented greater maladaptation, followed by molars and canines. The bases continued to maladaptation the model after the immediate polymerization, with no statistically significant difference.

scholarly journals The accuracy of gypsum casts obtained from the disinfected extended-pour alginate impressions through prolonged storage times

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Rania A. Sharif ◽  
Khalid M. Abdelaziz ◽  
Najla M. Alshahrani ◽  
Fatimah S. Almutairi ◽  
Mohrah A. Alaseri ◽  
...  
Keyword(s):  
Dimensional Stability ◽  
Storage Time ◽  
Prolonged Storage ◽  
Time Intervals ◽  
Superior Surface ◽  
Stability Data ◽  
Surface Detail ◽  
Storage Times ◽  
One Way Anova ◽  
Chemical Disinfection

Abstract Background Manufacturers of the extended-pour alginates claimed their dimensional stability through prolonged storage. No data confirmed the ability of these materials to maintain their dimensions and the reproduced oral details following their chemical disinfection. Therefore, this study evaluated the dimensional stability and surface detail reproduction of gypsum casts obtained from disinfected extended-pour alginate impressions through different storage time intervals. Methods Two hundred and forty three hydrocolloid impressions were made from one conventional (Tropicalgin) and two extended-pour (Hydrogum 5 and Chromaprint premium) alginates. These impressions were subjected to none, spray and immersion disinfection before their storage in 100% humidity for 0, 72 and 120 h. The dimensional stability and the surface detail reproduction were indirectly evaluated under low angle illumination on the resulted gypsum casts. At α = 0.05, the parametric dimensional stability data were analyzed using One-Way ANOVA and Tukey’s comparisons, while the nonparametric detail reproduction data were analyzed using KrusKal Wallis and Mann–Whitney's tests. Results All gypsum casts exhibited a degree of expansion; however, the recorded expansion values did not differ between test categories (P > 0.05). Generally, casts obtained from spray-disinfected impressions showed lower detail accuracy (P < 0.05). Immersion-disinfected extended-pour alginates produced casts with better detail accuracy following 120 h of storage (P < 0.05). Conclusion All alginates materials offer comparable cast dimensions under different testing circumstances. Extended-pour alginates offer casts with superior surface details following their immersion disinfection and 120 h of storage. Spray-disinfection using 5.25% sodium hypochlorite affects the surface details of casts obtained from conventional and extended-pour alginates adversely.

scholarly journals Effect of storage time and chlorhexidine addition on the mechanical properties of glass ionomer cements

2017 ◽  
Vol 16 ◽  
pp. 1-9
Author(s):  
Juliana de Carvalho Machado ◽  
Cristiane Duque ◽  
Josânia Pitzer de Oliveira ◽  
Angela Scarparo Caldo-Teixeira
Keyword(s):  
Mechanical Properties ◽  
Stainless Steel ◽  
Compressive Strength ◽  
Storage Time ◽  
Mechanical Characteristics ◽  
Mechanical Tests ◽  
Glass Ionomer Cements ◽  
Glass Ionomer ◽  
Strength Tests ◽  
Storage Times

Aims: To evaluate the effect of the chlorhexidine (CHX) incorporation and the storage time on the mechanical properties of glass ionomer cements (GICs). Methods: The following GICs were evaluated: Ketac Molar Easymix (KM), Vidrion R (VR) and Vitromolar (VM), containing or not CHX.  GIC liquid was modified by adding 1.25 % CHX digluconate and then manipulated with the power and placed into the stainless steel cylindrical or bar-shaped molds. GICs specimens were stored into water for 1, 7 and 28 days. After these periods, specimens were submitted to flexural, diametral tensile and compressive strength tests, according to ISO standards. Data from mechanical tests were statistically analyzed using 2-way ANOVA and Tukey tests. Results: Overall, the storage time did not influence any of the mechanical properties of the GICs tested. In contrast, the inclusion of CHX reduced significantly these properties for all GICs tested. KM presented the highest values of compressive strength for all storage times. KM + 1.25% CHX had lower compressive strength results than KM, however, it showed similar results when compared to another GICs without CHX. Conclusions: The presence of chlorhexidine, independent of the storage time, interfered on the mechanical characteristics of GIC.

scholarly journals Comparison of the accuracy of fixture-level impression making after splinting prosthetic components

2020 ◽  
Vol 10 (2) ◽  
pp. 5252-5258
Keyword(s):  
Dimensional Accuracy ◽  
Acrylic Resin ◽  
Significant Difference ◽  
Laboratory Procedures ◽  
Master Model ◽  
Implant Dentistry ◽  
Increase In Accuracy ◽  
Post Hoc ◽  
Digital Caliper ◽  
Specific Distance

Considering the effects of different impression-taking techniques on the dimensional accuracy of the final cast and controversies over the best technique in implant dentistry, the present study was undertaken to evaluate the effects of three different open-tray impression techniques on the dimensional accuracy of final casts for implants. A two-piece metallic index was prepared and a patient’s jaw was simulated by placing self-cured acrylic resin in the lower part of the index. Then 2 holes were produced in the acrylic resin at a specific distance from each other, and the analogs were placed in these holes. Three different open-tray impression techniques were evaluated using the upper segment of the index, which mimicked the specific tray. The dimensional accuracy of the casts was evaluated by comparing the distances between the predetermined points on the implant analogs and the positions of the points with similar distances on the master model. A digital caliper (accurate to 0.01 mm) was used to measure the distances. The differences in the measurements on the final casts were analyzed with SPSS 16, using Kruskal-Wallis test. Post hoc Mann-Whitney U test was used for two-by-two comparisons. There was a significant difference between the group in which the analogs and impression copings were not splinted and the group with impression coping splinting without analog splinting and the group with simultaneous splinting of the impression copings and implant analogs, in relation to distances between similar points on the master model. In this context, the second and third techniques better reconstructed the positions of the points. Splinting of impression copings with Duralay acrylic resin prevented the movement of impression copings during the impression-taking procedure and despite an increase in the accuracy of impression taking during splinting of analogs by Duralay acrylic resin, the increase in accuracy was not significant statistically; therefore, splinting of the impression copings without splinting of the analogs is recommended due to an increase in impression-taking accuracy and facilitation of laboratory procedures.

scholarly journals Dimensional Accuracy of Stone Casts Obtained with Multiple Pours into the Same Mold

2012 ◽  
Vol 2012 ◽  
pp. 1-5 ◽  
Author(s):  
Valdimar da Silva Valente ◽  
Artêmio Luiz Zanetti ◽  
Pedro Paulo Feltrin ◽  
Ricardo Tatsuo Inoue ◽  
Carmem Dolores Vilarinho Soares de Moura ◽  
...  
Keyword(s):  
Stainless Steel ◽  
Coordinate Measuring Machine ◽  
Dimensional Accuracy ◽  
Wait Time ◽  
Type Iv ◽  
Impression Technique ◽  
Fixed Prosthesis ◽  
Measuring Machine ◽  
Master Model ◽  
Made In

Aim. The aim of the present study was to compare the dimensional accuracy of stone casts obtained with vinyl polysiloxane molds through the double-impression technique with three pours into the same mold. Methods. A stainless steel master model was constructed simulating a three-unit fixed prosthesis. Twelve impressions were taken of this master model with addition silicone, using the double-impression technique. Three pours of type IV gypsum were then made into each mold, thus producing 36 casts. The pours were made 1 hour, 6 hours and 24 hours after the impression procedure. Next, intra- and interabutment measurements were made in a coordinate measuring machine. Results. Comparative analysis of the dimensional accuracy of stone casts resulting from multiple pours was not statistically significant in pours first and second (P>0.05). These values, however, were statistically significant at third pour in the height in abutment 1 and upper distance interabutment. Conclusion. The wait time (1 hour, and 6 hours) observed before pouring the stone into the same molds did not cause significant dimensional accuracy of the casts.

scholarly journals A Promising Potential of Brown Algae Sargassum polycystum as Irreversible Hydrocolloid Impression Material

Marine Drugs ◽  
2022 ◽  
Vol 20 (1) ◽  
pp. 55
Author(s):  
Nurlindah Hamrun ◽  
Bahruddin Talib ◽  
Muhammad Ruslin ◽  
Hasminar Pangeran ◽  
Mochammad Hatta ◽  
...  
Keyword(s):  
Dimensional Stability ◽  
Brown Algae ◽  
Dimensional Accuracy ◽  
Impression Material ◽  
Sargassum Polycystum ◽  
Impression Materials ◽  
Measurement Results ◽  
Irreversible Hydrocolloid ◽  
Dental Cast ◽  
Digital Caliper

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.

scholarly journals Effect of using Different Remineralizing Agents on Micro-shear Bond Strength of Nanohybrid Composite Resin

2020 ◽  
Vol 8 (D) ◽  
pp. 70-76
Author(s):  
Ebaa I. Alagha
Keyword(s):  
Bond Strength ◽  
Sodium Fluoride ◽  
Shear Bond Strength ◽  
Storage Time ◽  
Composite Resin ◽  
Significant Difference ◽  
Nanohybrid Composite ◽  
And Control ◽  
Storage Times ◽  
Positive Effect

AIM: This study was conducted to evaluate the effect of different remineralizing agents on micro-shear bond strength (SBS) of nanohybrid composite resin to dentin. METHODS: Thirty-six human molars were divided into four main equal groups (nine teeth each) according to the type of remineralizing agent used; nanohydroxyapatite, sodium fluoride, fluorohydroxyapatite, and control without remineralizing agent. Each group was divided into three equal subgroups (three teeth each) according to the storage time; 1 day, 1 month, and 3 months. Specially fabricated cylindrical plastic mold was made, and teeth were embedded vertically in the mold to the level of cementoenamel junction of the tooth leaving the occlusal surface projecting above the surface of the mold. Cylindrical fissure carbide bur was used in teeth preparation. Teeth were trimmed perpendicular to the long axes of them. Demineralizing agents (Nano hydroxyapatite, sodium fluoride, and fluorohydroxyapatite) were applied then adhesive system applied then composite resin was applied using five sections of a pediatric intravenous tube to act as molds for composite specimen then the specimens stored in artificial saliva at 37°C for different storage times in an incubator. The micro-SBS was assessed using universal testing machine. Then, the mode of failure for each group was determined using stereomicroscope device. Then, the obtained data were tabulated and statistically analyzed. One-way ANOVA was used to compare between more than two non-related samples. The significance level was set at p ≤ 0.05. Statistical analysis was performed with IBM SPSS Statistics. RESULTS: There was statistically significant difference between the four studied groups regarding bond strength at different storage times. Fluorohydroxyapatite had the highest bond strength mean values followed by nanohydroxyapatite, while the lowest value was the sodium fluoride group. CONCLUSION: Fluorohydroxyapatite and nanohydroxyapatite had a positive effect on micro-SBS to dentin, but sodium fluoride had a negative effect. The storage time increase had a positive effect on the micro-SBS of dentin with fluorohydroxyapatite and nanohydroxyapatite, also it had adverse effect on the dentin bond strength with sodium fluoride and control groups.

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