scholarly journals Comparison of Dimensional Accuracy of Four Different Die Materials before and after Disinfection of the Impression: An in vitro Study

2013 ◽  
Vol 14 (4) ◽  
pp. 668-674
Author(s):  
Yamini Nandini ◽  
KB Vinitha ◽  
M Smitha

ABSTRACT Background This study was conducted to compare the linear dimensional accuracy of die materials before and after disinfection of the impression. Type IV and V conventional dental stone, type IV-resin impregnated and copper-plated die materials were studied. Materials and methods A stainless-steel master die analogs to a complete veneer crown preparation with three scribed lines (I: vertical, II and III: horizontal) was machined and measurements were made from these scribed reference lines. Impressions were made with monophase addition silicone impression material for each of the specimens. 2% glutaraldehyde was used as a disinfectant. The fabricated dies were measured to the nearest 0.0001 mm. ANOVA and post hoc was carried out using Scheffe multiple comparison test at significance level of 0.05. Results Type IV resin-impregnated dental stone and copperplated dies approximated the dimensions of the master die. Type IV and V conventional dental stone dies showed greater variation in measurements. Statistically significant differences were observed for type IV resin-impregnated and copper-plated dies in dimension I and III. For dimension II no significant differences were found for dies fabricated from four die materials. A one-way analysis of variance indicated no statistical significant differences among the two groups of dies fabricated from disinfectant treated impressions and those fabricated from nondisinfectant treated impressions. Conclusion Type IV resin-impregnated dental stone and copper-plated dies are dimensionally more accurate than type IV and V conventional dental stone die materials. No significant linear distortion in the dies fabricated from the disinfected impressions was observed. How to cite this article Nandini Y, Vinitha KB, Manvi S, Smitha M. Comparison of Dimensional Accuracy of Four Different Die Materials before and after Disinfection of the Impression: An in vitro Study. J Contemp Dent Pract 2013;14(4):668-674.

2021 ◽  
Vol 7 (3) ◽  
pp. 166-171
Author(s):  
Pronoy Mukhopadhyay ◽  
Sattyam Wankhade ◽  
Jyoti Wankhade ◽  
Arun Khalikar

The precise outcome of any indirect casting, depends on the various procedures and materials involved through all its stages. The accurate fit against the prepared surface and the adaptation against the prepared margin depends on how accurately the tooth surface is captured in the impression made and how well it is reproduced in the die This study aims to study and compare the property of fine detail reproduction amongst six die materials.Over a pre-calibrated master die using custom tray, an impression record is made and poured using the six different die materials and the finest line reproduced is visualized under an optical fluorescent microscope at 50X magnification.The data obtained were statistically analysed using one-way ANOVA and subsequently assessed by post-hoc Tukey’s comparison to identify any significant differences between the groups. Epoxy resin die material (1.93 mm) showed a consistently excellent fine detail reproduction, followed by conventional Type V gypsum and Synthetic gypsum (15.91 mm), while Resin modified-Type IV and Type V and conventional Type IV gypsum dies (21.86mm) showed the least accuracy in fine reproduction.


Author(s):  
Anubhuti Bakshi ◽  
Rajat Dang

ABSTRACT Aim To evaluate surface hardness and dimensional accuracy of type IV dental stone after incorporation of disinfectants. Materials and methods A total of 100 specimens, 50 (40 mm⨯ 10 mm) disk shaped and 50 frustum cone shaped, were fab- ricated from type IV dental stone after incorporation of various disinfectants, namely glutaraldehyde (2%), iodophor (1.76%), chlorhexidine (2%), and sodium hypochlorite (1%), for evaluation of surface hardness and dimensional accuracy. Surface hardness was tested after 1- and 24-hour time interval using Rockwell hard- ness testing machine. Dimensional accuracy was measured using traveling microscope. Data obtained were compiled and analyzed statistically by using analysis of variance and post hoc test. Results Results showed significant decrease in surface hard- ness of samples incorporated with disinfectants at 1 hour as compared with control (distilled water). Surface hardness of all the samples increased with time and was almost equal to control group at 24-hour interval, with iodophor showing the maximum value in comparison with the other disinfectants used. When dimensional accuracy of all the groups was compared, iodophor and sodium hypochlorite were found to cause negative alterations. Conclusion Within the limitations of this in vitro study, it was concluded that incorporation of disinfectants in die stone during mixing did not affect the hardness value at 24-hour interval. Dimensional accuracy was altered by iodophor and sodium hypochlorite, but remained unaffected by chlorhexidine and glutaraldehyde. How to cite this article Bakshi A, Dang R. Effect of Incorpo- ration of Disinfectants on Surface Hardness and Dimensional Accuracy of Die Stone An in vitro Study. Int J Prosthodont Restor Dent 2017;7(3):86-91.


Author(s):  
Deebah Choudhary

Aim: To evaluate the influence of various obturating techniques on retreatment teeth. Place and Duration of Study: Department of Conservative Dentistry and Endodontics, Institute of Dental Sciences, Jammu and Kashmir, India between December 2019 and February 2020. Methodology: Sixty extracted mandibular premolars were randomly divided into three groups (n=20) based on the obturation technique adopted which endodontic treatment i.e., cold lateral compaction, thermoplasticized and GuttaFlow techniques. The samples were evaluated using micro-computed tomography for the volume before and after the retreatment to assess the remaining amount of filling material in the canals, and also the time taken for the removal of filling material during the retreatment. Data were analyzed using ANOVA followed by Post hoc test at P < 0.05. Results: The percentage of remaining filling material was between 17%-27%. The highest percentage of remaining filling material was seen in samples obturated with GuttaFlow (P < 0.05). The time required for retreatment was highly significant in thermoplasticized technique (P < 0.05). Conclusion: The type of obturating technique influenced the amount of filling material remained in the canal after retreatment and also the time taken during this removal.


2022 ◽  
Vol 10 (19) ◽  
pp. 29-33
Author(s):  
Sebastián M. Ulloa-Alvarez ◽  
María E. Guerrero-Coello ◽  
José E. Torracchi-Carrasco

Introduction: Endodontic retreatment seeks reentry to the root canal system to remove all filling material, identification and correction of pathological or iatrogenic defects. Objective: This study aimed to compare the dissolving capacity of eucalyptus oil, orange oil, and distilled water versus three types of endodontic cements. Materials and methods: Two hundred and four stainless steel molds were fabricated, where each cement sample was placed to the edge and left to set in the incubator, simulating normal oral conditions for 7 days. Subsequently, the solubility of each cement was analysed by immersing the samples in eucalyptus and orange oil for ten minutes in a static and ultrasonic environment. The solubility of the cement was evidenced by the difference between the weight before and after contact with the oils, data were statistically analysed with the ANOVA test and the post hoc Tukey bootstrap means test with 1,000 repetitions. Results: The control group and eucalyptus oil having no significant effect (p>0.05), the ultrasonic environment was found to be effective (p<0.05), whereas orange oil had better dissolution effects (p=0.004). Conclusions: The most susceptible cement was Sealapex, while the least soluble was MTA-Fillapex in all the solvents studied.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Hanna Boes ◽  
Sören Brüstle ◽  
Gholamreza Danesh ◽  
Stefan Zimmer ◽  
Mozhgan Bizhang

AbstractPreventing biofilm-related risks such as gingivitis and white spot lesions during orthodontic treatments is very challenging. The cleaning efficiencies of AirFloss Ultra and I-Prox P sulcus brushes were evaluated using an orthodontic phantom model. After attaching brackets onto black-coated maxillary KaVo teeth, a plaque substitute was applied. The evaluated tooth surfaces were divided into two areas. Cleaning was performed with an AirFloss Ultra with two (A-2) or four (A-4) sprays or an I-Prox P for two (I-2) or four (I-4) seconds. Images before and after cleaning were digitally subtracted, and the percentage of fully cleaned surfaces was determined (Adobe Photoshop CS5, ImageJ). Statistical analysis was performed by ANOVA and post hoc tests with Bonferroni correction (SPSS 25, p < 0.05). The mean values of total cleaning efficacy were 26.87% for I-2, 43.73% for I-4, 34.93%, for A-2 and 56.78% for A-4. The efficacy was significantly higher for A-4 than for A-2, I-4, and I-2. There were significant differences between the four groups. Repeated cleaning led to an improved result. Within the study limitations, the AirFloss Ultra with four sprays proved to be more efficient than the sulcus brush I-Prox P for cleaning.


2018 ◽  
Vol 19 (2) ◽  
pp. 130-136 ◽  
Author(s):  
HP Vivek ◽  
Seema Geetha ◽  
Sabari Chandramohan ◽  
Md Imranulla ◽  
PB Srinidhi

ABSTRACT Aim The aim of the study was to evaluate the effect of mouthrinses containing olive oil, fluoride, and their combination on enamel erosion. Materials and methods An in vitro study of 45 enamel specimens, which were prepared from 45 extracted teeth, was employed. Each specimen was subjected to 10 alternative demineralization and remineralization cycles. Remineralizing cycle includes 5 minutes exposure with one of the mouthrinse, and demineralizing cycle includes 3 minute exposure to 1% citric acid. Mean surface roughness (Ra) was measured from surfometry before and after cycles. Statistical tests used were Student's unpaired t-test and one-way analysis of variance (ANOVA), followed by Tukey's post hoc test. Results Among the three mouthrinses, Listerine and Xerostom showed maximum protection against erosion on enamel. The 2% olive oil mouthrinse showed the least protection against erosion on enamel. Conclusion The study indicated that the Listerine and Xerostom mouthrinses are valuable preventive measures. Clinical significance Mouthrinses are effective for lessening erosive demineralization and in aggregating remineralization of tooth surfaces which are the important factors to prevent enamel erosion. How to cite this article Vivek HP, Prashant GM, Geetha S, Chandramohan S, Imranulla M, Srinidhi PB. Effect of Mouthrinses containing Olive Oil, Fluoride, and Their Combination on Enamel Erosion: An in vitro Study. J Contemp Dent Pract 2018;19(2):130-136.


2019 ◽  
Vol 36 (2) ◽  
Author(s):  
Fahad Alkhudhairy ◽  
Sulieman S. Al-Johany ◽  
Mustafa Naseem ◽  
Mohammed Bin-Shuwaish ◽  
Fahim Vohra

Objective: The purpose of the present study was to assess dentin shear bond strength (SBS) and mode of bond failure of bioactive cement (BA) in comparison to conventional resin cement when photosensitized by Er,Cr:YSGG Laser (ECL). Methods: The present in-vitro study was carried out from March 2019 to May 2019. Sixty permanent non-carious, intact, non-fractured molars were isolated and mounted vertically in acrylic resin. Buccal surface of each molar tooth was ground, polished and surface treated with ECL. Ketac conditioner was applied on the surface washed and air dried surface. Tetric -N-Bond adhesive was applied on forty-five samples and light cured. The specimens were allocated into four groups (n=15) according to the type of cement used i.e., Calibra (C), BA, Variolink II (V) and Maxcem-Elite (ME). For SBS testing was performed using the universal testing machine. Eight samples from each group were assessed for modes of failure. Means and standard deviations were compared using analysis of variance (ANOVA) and Tukey’s post hoc test at a significance level of p < 0.05. Results: The highest mean SBS was observed in group ECL-C (21.55±3.08). The lowest mean SBS was displayed in group ECL-ME (14.25±3.55). Mean SBS values for group ECL-C (21.55±3.08) and group ECL-V (20.74±4.15) were comparable (p <0.05). Similarly, SBS values of group ECL-BA (15.48±3.62) and group ECL-ME (14.25±3.55) were comparable (p <0.05). Conclusion: Dentin surface conditioned with Er,Cr:YSGG and bonded to C and V cements exhibit favourable bond strength values. doi: https://doi.org/10.12669/pjms.36.2.1284 How to cite this:Alkhudhairy F, Al-Johany SS, Naseem M, Bin-Shuwaish M, Vohra F. Dentin bond strength of bioactive cement in comparison to conventional resin cement when photosensitized with Er,Cr:YSGG Laser. Pak J Med Sci. 2020;36(2):---------.   doi: https://doi.org/10.12669/pjms.36.2.1284 This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.


Author(s):  
Sattyam V Wankhade ◽  
Kaushal V Sanghavi ◽  
Vilas Rajguru ◽  
Jyoti Lokade

ABSTRACT Background and objectives This in vitro study evaluated and compared the abrasion resistance of types IV and V gypsums, resin-modified type IV and type V gypsums, synthetic gypsum, and epoxy resin die material at two different time intervals spanning a period of 24 hours. Materials and methods A total of 10 dies of each die material were fabricated and tested for abrasion resistance at each time interval. An average of five readings was taken for the test, measuring the rate of abrasion of the materials. Results All the tested properties of the epoxy resin material were far superior to those of the other materials (being tested). Resin-modified type IV gypsum had significantly better abrasion resistance than its type V counterpart at setting. However, when tested at 24 hours, both materials had comparable resistance to abrasion, which was the highest among the gypsum-based materials. Interpretation and conclusion Epoxy die resin had the most superior physical properties of all. A significant decrease in the rate of abrasion (-38 to -83%) was noted, when the gypsumbased products were tested at 24 hours. From the data obtained in this study, it is recommended that when gypsum-based materials are used, to wait at least 24 hours prior to separating casts from impressions (and subsequent laboratory procedures) to avoid damage to the casts and dies. Abbreviations RR IV: Resin modified type IV gypsum; RR V: Resin modified type V gypsum; S: Synthetic gypsum; V: Type V gypsum; IV: Type IV gypsum. How to cite this article Wankhade SV, Sanghavi KV, Rajguru V, Lokade J. A Comparative Evaluation of Six Commonly used Types of Die Materials for the Property of Abrasion Resistance, at Two Time Intervals: An in vitro Study. Int J Prosthodont Restor Dent 2013;3(1):1-6.


2021 ◽  
Vol 45 (1) ◽  
Author(s):  
Engy M. Kataia ◽  
Mohamed Mokhtar Nagy ◽  
Mohamed M. Kataia ◽  
Hala Fayek Khalil

Abstract Background Comparing shaping ability of Azure and Fanta AF One in rotation and reciprocation. This study was conducted on 40 resin blocks, having canal curvatures 30°-angle and of 16-mm length. The blocks were assigned to 4-groups according to the instrument and motion used: Azure/Rotation (A/Rt), Fanta AF one/Rotation (F/Rt), Azure/Reciprocation (A/Rec) and Fanta AF one/Reciprocation (F/Rec). For both systems single file 25, taper 0.06 were used. Digital images were taken before and after instrumentation. Adobe Photoshop was used to overlap post and pre-instrumentation images to assess canal transportation at 1, 4, 7-mm; representing apical, middle and cervical levels respectively. Stopwatch was used to document the time taken for canal preparation. One-way ANOVA followed by Tukey post hoc test, used to compare between more than two groups in non-related samples. Results At the apical level, no statistically significant difference was found between both files in either rotation or reciprocation. However, reciprocation motion showed significantly lower transportation levels in both files. No significant difference was found among groups at the middle and cervical levels. Regarding preparation time, Reciprocation in both groups was significantly longer. Conclusions The use of reciprocation motion showed minimized apical canal transportation in both files however in longer preparation time.


2012 ◽  
Vol 13 (1) ◽  
pp. 98-106 ◽  
Author(s):  
Kishan Singh ◽  
Sukant Sahoo ◽  
KD Prasad ◽  
Meenu Goel ◽  
Anupam Singh

ABSTRACT Production of exemplary crowns and fixed partial dentures depends upon the usage of impression material and its technique of usage that accurately reproduces prepared teeth and their relationship to the adjacent oral structure. Aim To evaluate the linear dimensional accuracy of the elastomeric impressions using various impression techniques using different combinations of viscosities of impression materials. Materials and methods Crown preparation was done in a dentulous acrylic resin denture base model with six natural teeth embedded into it was made to represent the dentulous maxillary arch. A total of 55 impressions were obtained and poured in die stone using various impression techniques with different combinations of viscosities of impression materials. Results Among the six techniques used, the heavy body light body two-step technique using custom tray showed the least distortion which was closely followed by the putty wash two-step technique with 2 mm spacer using stock tray. Conclusion The study revealed that the heavy body light body two-step technique with custom tray provided the best results. Clinical significance Dimensional accuracy of impressions is very much required for precisely fitting of prosthesis. This study may be helpfull to select the technique and materials as per clinical requirement of accuracy of impressions. How to cite this article Singh K, Sahoo S, Prasad KD, Goel M, Singh A. Effect of Different Impression Techniques on the Dimensional Accuracy of Impressions using Various Elastomeric Impression Materials: An in vitro Study. J Contemp Dent Pract 2012;13(1):98-106.


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