scholarly journals Effect of Die Materials on Marginal and Internal Adaptation of Zirconia Copings: An In Vitro Study

2021 ◽  
Vol 15 (1) ◽  
pp. 708-716
Author(s):  
Raja M. Al-Mussawi ◽  
Farzaneh Farid ◽  
Julfikar Haider
Keyword(s):  
In Vitro Study ◽  
Mean Value ◽  
Repeated Measure ◽  
Marginal Gap ◽  
Mean Values ◽  
Type Iv ◽  
Die Materials ◽  
Cad Cam ◽  
Internal Gap

Aim: Close adaptation of cemented CAD/CAM restorations to their abutments is highly dependent on precise impressions and accurate replicas of teeth and adjacent oral tissues. This in-vitro study compared the effect of two die materials, as physical replicas of prepared teeth, on internal and marginal adaptations of zirconia copings to their corresponding abutments. Materials and Methods: A virtual model simulating a prepared premolar was designed and used for the milling of thirty identical metal models. Impression was taken of all models by Polyvinyl siloxane material. Fifteen impressions were poured in with Type IV stone and the other fifteen with polyurethane resin to make dies. All dies were scanned, and for each of them, zirconia coping was designed and milled. The copings were cemented to their corresponding metal models. Marginal gap between each coping and its metal model was measured at 20 points with a stereomicroscope (×60). Then the specimens were sectioned into two halves, and the internal gap was measured at seven points, including right and left cervico-axial, mid-axial, occluso-axial, and mid-occlusal. The data were analyzed with an independent T-test and repeated measure ANOVA at a 95% confidence level (p<0.05). Results: Mean value of marginal gap for Type IV stone and Exakto-Form groups were 54.31 ± 4.11 μm and 56.25 ± 4.24 μm, respectively. Mean values of the internal gaps for both groups ranged from 48 μm to 120 μm. Conclusion: Based on the results of this study, an internal and marginal adaptation of zirconia copings designed on digitized polyurethane and Type IV stone dies are clinically acceptable.

scholarly journals Influence of Intra-Oral Scanner (I.O.S.) on The Marginal Accuracy of CAD/CAM Single Crowns

2019 ◽  
Vol 16 (4) ◽  
pp. 544 ◽  
Author(s):  
Francesco Ferrini ◽  
Gianpaolo Sannino ◽  
Carlo Chiola ◽  
Paolo Capparé ◽  
Giorgio Gastaldi ◽  
...  
Keyword(s):  
Standard Deviation ◽  
In Vitro Study ◽  
Mean Value ◽  
Vitro Study ◽  
Computer Assisted ◽  
Marginal Gap ◽  
Significant Difference ◽  
Cad Cam ◽  
True Definition

The aim of this in vitro study was to compare the quality of digital workflows generated by different scanners (Intra-oral digital scanners (I.O.S.s)) focusing on marginal fit analysis. A customized chrome-cobalt (Cr-Co) implant abutment simulating a maxillary right first molar was fixed in hemi-maxillary stone model and scanned by eight different I.O.S.s: Omnicam® (Denstply Sirona, Verona, Italy) CS3500®, CS3600®, (Carestream Dental, Atlanta, GA, USA), True Definition Scanner® (3M, St. Paul, MN, USA), DWIO® (Dental Wings, Montreal, Quebec, Canada), PlanScan® (Planmeca Oy, Helsinki, Finland), 3D PROGRESS Plus® (MHT, Verona, Italy), TRIOS 3® (3Shape, Copenhagen, Denmark). Nine scans were performed by each tested I.O.S. and 72 copings were designed using a dental computer-assisted-design/computer-assisted-manufacturing (CAD/CAM) software (exocad GmbH, Darmstadt, Germany). According to CAD data, zirconium dioxide (ZrO2) copings were digitally milled (Roland DWX-50, Irvine, CA, USA). Scanning electron microscope (SEM) direct vision allowed for marginal gap measurements in eight points for each specimen. Descriptive analysis was performed using mean, standard deviation, and median, while the Kruskal–Wallis test was performed to determine whether the marginal discrepancies were significantly different between each group (significance level p < 0.05). The overall mean marginal gap value and standard deviation were 53.45 ± 30.52 μm. The minimum mean value (40.04 ± 18.90 μm) was recorded by PlanScan®, then 3D PROGRESS Plus® (40.20 ± 21.91 μm), True Definition Scanner® (40.82 ± 26.19 μm), CS3500® (54.82 ± 28.86 μm) CS3600® (59,67 ± 28.72 μm), Omnicam® (61.57 ± 38.59 μm), DWIO® (62.49 ± 31.54 μm), while the maximum mean value (67.95 ± 30.41 μm) was recorded by TRIOS 3®. The Kruskal–Wallis tests revealed a statistically significant difference (p-value < 0.5) in the mean marginal gaps between copings produced by 3D PROGRESS Plus®, PlanScan, True Definition Scanner, and the other evaluated I.O.S.s. The use of an I.O.S. for digital impressions may be a viable alternative to analog techniques. Although in this in vitro study PlanScan®, 3D PROGRESS Plus® and True Definition Scanner® may have showed the best performances, all I.O.S.s tested could provide clinically encouraging results especially in terms of marginal accuracy, since mean marginal gap values were all within the clinically acceptable threshold of 120 μm.

scholarly journals Marginal and Internal Fit of Ceramic Prostheses Fabricated from Different Chairside CAD/CAM Systems: An In Vitro Study

2021 ◽  
Vol 11 (2) ◽  
pp. 857
Author(s):  
Keunbada Son ◽  
Kyu-Bok Lee
Keyword(s):  
Computer Aided Design ◽  
In Vitro Study ◽  
Vitro Study ◽  
Marginal Gap ◽  
Significant Difference ◽  
Cad Cam ◽  
Ceramic Crowns ◽  
Internal Fit ◽  
Cam Systems

The purpose of this in vitro study was to evaluate marginal and internal fits of ceramic crowns fabricated with chairside computer-aided design and manufacturing (CAD/CAM) systems. An experimental model based on ISO 12836:2015 was digitally scanned with different intraoral scanners (Omnicam (CEREC), EZIS PO (DDS), and CS3500 (Carestream)). Ceramic crowns were fabricated using the CAD/CAM process recommended by each system (CEREC, EZIS, and Carestream systems; N = 15). The 3-dimensional (3D) marginal and internal fit of each ceramic crown was measured using a 3D inspection software (Geomagic control X). Differences among the systems and various measurements were evaluated using the Kruskal–Wallis test. Statistically significant differences were validated using pairwise comparisons (α = 0.05). Occlusal gaps in the CEREC, EZIS, and Carestream groups were 113.0, 161.3, and 438.2 µm, respectively (p < 0.001). The axial gaps were 83.4, 78.0, and 107.9 µm, respectively. The marginal gaps were 77.8, 99.3, and 60.6 µm, respectively, and the whole gaps were 85.9, 107.3, and 214.0 µm, respectively. Significant differences were observed with the EZIS system compared with the other two systems in terms of the marginal gap sizes. The CEREC system showed no significant differences among the four measured regions. However, the EZIS and Carestream systems did show a statistically significant difference (p < 0.05). All three systems were judged to be capable of fabricating clinically acceptable prostheses, because the marginal gap, which is the most important factor in the marginal fit of prostheses, was recorded to be below 100 µm in all three systems.

scholarly journals Comparative evaluation of fine detail reproduction of six different die materials- An in-Vitro study

2021 ◽  
Vol 7 (3) ◽  
pp. 166-171
Author(s):  
Pronoy Mukhopadhyay ◽  
Sattyam Wankhade ◽  
Jyoti Wankhade ◽  
Arun Khalikar
Keyword(s):  
In Vitro Study ◽  
Tooth Surface ◽  
Type Iv ◽  
Fine Detail ◽  
Die Materials ◽  
Die Material ◽  
Type V ◽  
Post Hoc ◽  
Conventional Type

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.

scholarly journals 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

2013 ◽  
Vol 3 (1) ◽  
pp. 1-6
Author(s):  
Sattyam V Wankhade ◽  
Kaushal V Sanghavi ◽  
Vilas Rajguru ◽  
Jyoti Lokade
Keyword(s):  
Abrasion Resistance ◽  
Comparative Evaluation ◽  
In Vitro Study ◽  
Vitro Study ◽  
Time Intervals ◽  
Type Iv ◽  
Die Materials ◽  
Die Material ◽  
Type V

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.

scholarly journals Effect of CAD/CAM Ceramic Thickness on Shade Masking Ability of Discolored Teeth: In Vitro Study

2021 ◽  
Vol 18 (24) ◽  
pp. 13359
Author(s):  
Passent Ellakany ◽  
Marwa Madi ◽  
Nourhan M. Aly ◽  
Zainb S. Al-Aql ◽  
Maher AlGhamdi ◽  
...  
Keyword(s):  
In Vitro Study ◽  
Total Sample ◽  
Dental Restoration ◽  
Vitro Study ◽  
Tooth Structure ◽  
Die Materials ◽  
Cad Cam ◽  
The Difference ◽  
Ceramic Thickness

Shade matching is a common challenge that dentists face during fabrication of esthetic dental restoration. Thus, the aim of the current study was to assess the masking ability of two types of CAD/CAM ceramics for gaining high esthetic prosthesis. This in vitro study used a total sample size of 66 lithium disilicate (LD) and leucite reinforced (LR) CAD/CAM ceramics sub-grouped into three thicknesses: 0.5, 1, and 1.5 mm. Nine shades of natural dentin die materials were prepared as a replica of the underlying tooth structure. The difference in color (ΔE) and translucency parameter (TP) were assessed for both tested ceramics at the three thicknesses. One-way ANOVA was performed to compare the three thicknesses of each ceramic, followed by multiple pairwise comparisons between both ceramics. LR had significantly higher ΔE than LD at all thicknesses used unlike the case in TP. Thickness of 0.5 mm exhibited the highest ΔE and TP, while 1.5 mm thickness showed the lowest ΔE and TP in both ceramics. Increase in ceramic thickness had a great impact on both color masking ability of the underlying tooth structure and its translucency. The higher the ceramic thickness, the better the masking ability and the lower the translucency was reported.

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
Keyword(s):  
In Vitro Study ◽  
Dimensional Accuracy ◽  
Significance Level ◽  
Type Iv ◽  
Multiple Comparison Test ◽  
Before And After ◽  
Die Materials ◽  
Crown Preparation ◽  
Post Hoc

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.

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