scholarly journals Impact of Sandblasting on Morphology, Structure and Conductivity of Zirconia Dental Ceramics Material

Materials ◽  
2021 ◽  
Vol 14 (11) ◽  
pp. 2834
Author(s):  
Marko Jakovac ◽  
Teodoro Klaser ◽  
Borna Radatović ◽  
Arijeta Bafti ◽  
Željko Skoko ◽  
...  
Keyword(s):  
Phase Transformation ◽  
Computer Aided Design ◽  
Adhesive Bonding ◽  
Ceramic Materials ◽  
Powder Size ◽  
Dental Ceramics ◽  
Air Abrasion ◽  
Al2o3 Powder ◽  
Computer Aided ◽  
The Impact

Over the last decade, zirconia (ZrO2)-based ceramic materials have become more applicable to modern dental medicine due to the sustained development of diverse computer-aided design/computer-aided manufacturing (CAD/CAM) systems. However, before the cementation and clinical application, the freshly prepared zirconia material (e.g., crowns) has to be processed by sandblasting in the dental laboratory. In this work, the impact of the sandblasting on the zirconia is monitored as changes in morphology (i.e., grains and cracks), and the presence of impurities might result in a poor adhesive bonding with cement. The sandblasting is conducted by using Al2O3 powder (25, 50, 110 and 125 µm) under various amounts of air-abrasion pressure (0.1, 0.2, 0.4 and 0.6 MPa). There has been much interest in both the determination of the impact of the sandblasting on the zirconia phase transformations and conductivity. Morphology changes are observed by using Scanning Electron Microscope (SEM), the conductivity is measured by Impedance Spectroscopy (IS), and the phase transformation is observed by using Powder X-Ray Diffraction (PXRD). The results imply that even the application of the lowest amount of air-abrasion pressure and the smallest Al2O3 powder size yields a morphology change, a phase transformation and a material contamination.

scholarly journals CAD/CAM DENTAL CERAMICS IN RESTORATIVE DENTISTRY

2021 ◽  
pp. 176-179
Author(s):  
N. B. Berin Dhanya
Keyword(s):  
Computer Aided Design ◽  
Design Education ◽  
Computer Software ◽  
Ceramic Materials ◽  
Computer Applications ◽  
Orthodontic Appliances ◽  
Dental Ceramics ◽  
Computer Aided ◽  
Cad Cam ◽  
Ceramic Blocks

Computer Aided Design and Computer Aided Manufacturing (CAD/ CAM) is a pair of often interdependent industrial computer applications that have greatly influenced the chain of processes between the initial design and the final realization of a product. It refers to the computer software that is used to both design and manufacture products.It is to improve the design and creation of dental restorations,especially dental prostheses, including crowns,crown lays,veneers,inlays and onlays, fixed bridges, dental implant restorations, dentures (removable or fixed), and orthodontic appliances. These are systems that can design and produce restoration out of blocks or blanks of ceramics. CAD/CAM is one of the highly competent dental lab technologies. Without this technology we wouldn't have the range and quality of products available.Hand-building and manual techniques still very much have their place and design education needs to treasure and foster these skills so that future generations will have the 'hands-on' skills to understand the man-made world and provide the next generation of engineers,designers and technicians. CAD/CAM was first introduced to dentistry in the mid-1980s. Both chair side and chair side-laboratory integrated procedures are available for this restoration fabrication.In selecting which procedure to follow,consideration should be given to aesthetic demands, chair side time, laboratory costs, number of visits and convenience and return on investment associated with CAD/CAM equipment. Depending on the method selected, CAD/CAM ceramic blocks available for restoration fabrication include leucite-reinforced ceramics, lithium di silicate, zirconia, and composite resin.In order to determine which type of ceramic to use,the practitioner must take into account aesthetics,strength,and ease of customizing milled restorations. It gives both the dentist and the laboratory technician an opportunity to automate fixed restoration fabrication and to offer patients highly aesthetic restorations in just one or two visits.These technologies are responsible for massive gains in both productivity and quality,particularly since the 1980s.This article is to provide information on restorative procedures and ceramic materials using CAD/CAM technology.

Bone tissue engineering in the greater omentum with computer-aided design/computer-aided manufacturing scaffolds is enhanced by a periosteum transplant

2020 ◽  
Author(s):  
Hendrik Naujokat ◽  
Klaas Loger ◽  
Juliane Schulz ◽  
Yahya Açil ◽  
Jörg Wiltfang
Keyword(s):  
Bone Formation ◽  
Bone Tissue ◽  
Computer Aided Design ◽  
Bone Tissue Regeneration ◽  
Histological Evaluation ◽  
Greater Omentum ◽  
Collagen Membrane ◽  
Computer Aided ◽  
3D Printed ◽  
The Impact

Aim: This study aimed to evaluate two different vascularized bone flap scaffolds and the impact of two barrier membranes for the reconstruction of critical-size bone defects. Materials & methods: 3D-printed scaffolds of biodegradable calcium phosphate and bioinert titanium were loaded with rhBMP-2 bone marrow aspirate, wrapped by a collagen membrane or a periosteum transplant and implanted into the greater omentum of miniature pigs. Results: Histological evaluation demonstrated significant bone formation within the first 8 weeks in both scaffolds. The periosteum transplant led to enhanced bone formation and a homogenous distribution in the scaffolds. The omentum tissue grew out a robust vascular supply. Conclusion: Endocultivation using 3D-printed scaffolds in the greater omentum is a very promising approach in defect-specific bone tissue regeneration.

Surface Roughness of Two CAD/CAM Restorative Materials as Affected by Chewing Simulation v1

2022 ◽  
Author(s):  
eaeldwakhly not provided
Keyword(s):  
Surface Roughness ◽  
Computer Aided Design ◽  
Surface Characteristics ◽  
Ceramic Materials ◽  
Study Groups ◽  
Significance Level ◽  
Chewing Simulation ◽  
Computer Aided ◽  
Cad Cam ◽  
The Individual

This study was conducted to assess the surface characteristics in terms of roughness of two CAD/CAM (Computer-Aided-Design/Computer-Aided Manufacturing)restorative material spre and post chewing simulation exposure. Methods: Specimens were prepared from two CAD/CAM ceramic materials: Cerec Blocs C and IPS e-max ZirCAD. A total of 10 disks were prepared for each study group. 3D optical noncontact surface profiler was used to test the surface roughness (ContourGT, Bruker, Campbell, CA, USA). A silicone mold was used to fix the individual samples using a self-curing resin. Surface roughness (SR) was examined pre and post exposure to chewing simulation. 480,000 simulated chewing cycles were conducted to mimic roughly two years of intraoral clinical service. The results data was first tested for normality and equal variance (Levene’s test >0.05) then examined with paired and independent sample t-test at a significance level of (p < 0.05). Results:The two CAD-CAM materials tested exhibited increased surface roughness from baseline. The highest mean surface roughness was observed in Cerec blocs C group after chewing simulation (2.34 µm± 0.62 µm). Whereas the lowest surface roughness was observed in IPS e.max ZirCAD group before chewing simulation (0.42 µm± 0.16 µm). Both study groups exhibited significantly different surface roughness values (p< 0.05). There was a statistically higher surface roughness values after the chewing simulation in Cerec blocs C when compared to IPS e.max ZirCAD groups (p = 0.000).Conclusion:Even though both tested CAD/CAM materials differ in recorded surface roughness values, results were within clinically accepted values.

Effect of In-office Bleaching on Color, Translucency, and Whiteness Variations in CAD-CAM Monolithic Materials

2021 ◽  
Author(s):  
RG Fonseca ◽  
RC Peńa ◽  
R Simóes ◽  
AC Ramos ◽  
LN Dovigo
Keyword(s):  
Optical Properties ◽  
Computer Aided Design ◽  
Calculated Data ◽  
Color Difference ◽  
Deionized Water ◽  
Stain Removal ◽  
Computer Aided ◽  
Cad Cam ◽  
Aided Design ◽  
The Impact

SUMMARY Little is known about the impact of bleaching on the optical properties of computer-aided design and computer-aided manufactured (CAD-CAM) monolithic materials. The aim of the present study was to evaluate the effect of one session of in-office bleaching on stain removal, staining susceptibility, translucency, and whiteness variations of CADCAM monolithic materials. Disks were fabricated from Lava Ultimate (LU), Vita Enamic (VE), Vita Suprinity (VS), and IPS e.max CAD (IPS). A spectrophotometer was used to register Commission Internationale de l’Eclairage L*a*b* coordinates. For stain removal, 80 specimens from each material were assessed at baseline (R0) and after immersion in deionized water or coffee for 365 days followed or not by bleaching with 40% hydrogen peroxide (R1). For staining susceptibility, 80 specimens from each material were analyzed at baseline (R0’), and after having been bleached or not and immersed in deionized water or coffee (R1’). Both analyses were calculated as the color difference (ΔE00) between R1-R0 and R1’-R0’, respectively. Differences in translucency (ΔTP00) and whiteness (ΔWID) between R1-R0 and R1’-R0’ were also calculated. Data were analyzed by three-way ANOVA and the Games-Howell post hoc test (α=0.05). Clinical significance was based on 50%:50% perceptibility and acceptability thresholds for ΔE00, ΔTP00 and ΔWID, respectively. Surfaces were analyzed by scanning electron microscopy. Coffee increased ΔE00 in LU, VE, and VS, and decreased their translucency and whiteness, whereas the IPS had only its whiteness affected. Bleaching after immersion in coffee decreased ΔE00 in LU and VE, and increased translucency and whiteness of LU, VE, and VS. No effect was observed on IPS. Bleaching before immersion in coffee decreased translucency of LU, but within the acceptable interval, while VE exhibited lower ΔE00, and became more translucent and less dark. Both VS and IPS were not affected. One session of in-office bleaching benefited optical properties of the previously stained LU, VE, and VS, without increasing their susceptibility to staining or adversely providing clinically unacceptable variations in their translucency and whiteness. All variations exhibited by the IPS were below the perceptible threshold.

scholarly journals Application Solid Laser-Sintered or Machined Ti6Al4V Alloy in Manufacturing of Dental Implants and Dental Prosthetic Restorations According to Dentistry 4.0 Concept

Processes ◽  
2020 ◽  
Vol 8 (6) ◽  
pp. 664 ◽  
Author(s):  
Leszek A. Dobrzański ◽  
Lech B. Dobrzański ◽  
Anna Achtelik-Franczak ◽  
Joanna Dobrzańska
Keyword(s):  
Dental Implants ◽  
Computer Aided Design ◽  
Bending Strength ◽  
Ti6al4v Alloy ◽  
Cnc Machining ◽  
Live Cells ◽  
Computer Aided ◽  
Aided Design ◽  
The Impact

This paper presents a comparison of the impact of milling technology in the computer numerically controlled (CNC) machining centre and selective laser sintering (SLS) and on the structure and properties of solid Ti6Al4V alloy. It has been shown that even small changes in technological conditions in the SLS manufacturing variant significantly affect changes from two to nearly two and a half times in tensile and bending strengths. Both the tensile and bending strength obtained in the most favourable manufacturing variant by the SLS method is over 25% higher than in the case of cast materials subsequently processed by milling. Plug-and-play SLS conditions provide about 60% of the possibilities. Structural, tribological and electrochemical tests were carried out. In vitro biological tests using osteoblasts confirm the good tendency for the proliferation of live cells on the substrate manufactured under the most favourable SLS conditions. The use of SLS additive technology for the manufacturing of dental implants and abutments made of Ti6Al4V alloy in combination with the digitisation of dental diagnostics and computer-aided design and manufacture of computer-aided design/manufacturing (CAD/CAM) following the idea of Dentistry 4.0 is the best choice of technology for manufacturing of prosthetic and implant devices used in dentistry.

scholarly journals Rotary Ultrasonic Machining of Dental Ceramics: A Preliminary Study on Subsurface Cracks

2010 ◽  
Vol 4 (2) ◽  
Author(s):  
Zhichao Li ◽  
Weilong Cong ◽  
Matthew Stanco ◽  
Zhigang Xu ◽  
Zhijian Pei ◽  
...  
Keyword(s):  
Computer Aided Design ◽  
Dental Ceramics ◽  
Ultrasonic Machining ◽  
Abrasive Machining ◽  
Rotary Ultrasonic Machining ◽  
Machining Processes ◽  
Subsurface Cracks ◽  
Computer Aided ◽  
Cad Cam ◽  
Aided Design

Commercially available dental computer aided design/computer aided manufacture (CAD/CAM) systems usually use abrasive machining processes such as diamond grinding and milling. One of the major disadvantages of abrasive machining processes is subsurface cracks. In the present paper, rotary ultrasonic machining (RUM) technology is introduced into machining of alumina dental ceramics. The subsurface cracks are observed under scanning electron microscope. Effects of ultrasonic vibration on the subsurface cracks are also investigated. Results show that RUM is a very promising process to significantly reduce subsurface cracks in CAD/CAM of dental ceramics.

Organizational Effectiveness of Computer-Aided Design

1987 ◽  
Vol 31 (2) ◽  
pp. 214-217
Author(s):  
Douglas H. Harris ◽  
Steven M. Casey
Keyword(s):  
Organizational Effectiveness ◽  
Computer Aided Design ◽  
Working Environment ◽  
Specific System ◽  
Cad System ◽  
Organizational Issues ◽  
Computer Aided ◽  
Major Factors ◽  
Aided Design ◽  
The Impact

A methodology for measuring the organizational effectiveness of computer-aided design (CAD) was developed and applied. A total of 295 of the 500 most frequent users of CAD in a major aerospace company provided data for the study. User-CAD effectiveness was found to be influenced by 43 major factors and 145 specific system and organizational issues. The 43 factors were classified into the following categories: system functions, system hardware, working environment, system reliability and consistency, user access, user support and training, and system administration. Indexes of User-CAD Effectiveness (UE) and System Availability and Reliability (AR) were combined into an Index of CAD Organizational Effectiveness (OE). Through the application of these methods and indexes, CAD system and organizational deficiencies can be diagnosed, potential high-payoff improvements can be identified, and the impact of developmental efforts can be assessed.

Computer-aided design versus sketching: An exploratory case study

2012 ◽  
Vol 26 (3) ◽  
pp. 317-335 ◽  
Author(s):  
David Veisz ◽  
Essam Z. Namouz ◽  
Shraddha Joshi ◽  
Joshua D Summers
Keyword(s):  
Design Process ◽  
Computer Aided Design ◽  
Mechanical Engineering ◽  
Computer Assisted ◽  
Cad Tools ◽  
Design Project ◽  
Computer Aided ◽  
Aided Design ◽  
The Impact

AbstractThis paper presents a preliminary comparison between the role of computer-aided design (CAD) and sketching in engineering through a case study of a senior design project and interviews with industry and academia. The design team consisted of four senior level mechanical engineering students each with less than 1 year of professional experience are observed while completing an industry sponsored mechanical engineering capstone design project across a 17 week semester. Factors investigated include what CAD tools are used, when in the design process they are implemented, the justification for their use from the students' perspectives, the actual knowledge gained from their use, the impact on the final designed artifact, and the contributions of any sketches generated. At each design step, comparisons are made between CAD and sketching. The students implemented CAD tools at the onset of the project, generally failing to realize gains in design efficiency or effectiveness in the early conceptual phases of the design process. As the design became more concrete, the team was able to recognize clear gains in both efficiency and effectiveness through the use of computer assisted design programs. This study is augmented by interviews with novice and experienced industry users and academic instructors to align the trends observed in the case study with industry practice and educational emphasis. A disconnect in the perceived capability of CAD tools was found between novice and experienced user groups. Opinions on the importance of sketching skills differed between novice educators and novice industry professionals, suggesting that there is a change of opinion as to the importance of sketching formed when recent graduates transition from academia to industry. The results suggest that there is a need to emphasize the importance of sketching and a deeper understanding as to the true utility of CAD tools at each stage of the design process.

Ceramic Fragments and Metal-free Full Crowns: A Conservative Esthetic Option for Closing Diastemas and Rehabilitating Smiles

2013 ◽  
Vol 38 (6) ◽  
pp. 567-571 ◽  
Author(s):  
ME Miranda ◽  
KA Olivieri ◽  
FJ Rigolin ◽  
RT Basting
Keyword(s):  
Computer Aided Design ◽  
Color Stability ◽  
Dental Ceramics ◽  
Metal Free ◽  
Anterior Teeth ◽  
Computer Aided ◽  
Adhesive Cementation ◽  
Ceramic Crowns ◽  
Tooth Preparation ◽  
Aided Design

SUMMARY Dental ceramics make it possible to restore anterior teeth that have been esthetically compromised, presenting a high resistance to wear, biocompatibility, color stability, and low thermal conductivity. The development of different types of ceramic and techniques for adhesive cementation have made it possible to produce more conservative restorations without involving the healthy dental structure and with minimally invasive preparation, such as the bonding of ceramic fragments. The purpose of this article is to describe a clinical case in which diastemas were closed by using nanofluorapatite ceramic (e.max Ceram, Ivoclar-Vivadent) fragments on teeth 7 and 10 with minimal tooth preparation and metal-free ceramic crowns (e-max Ceram) reinforced with zirconia copings through a computer-aided design/computer-aided manufacturing system (Lava, 3M-ESPE) on teeth 8 and 9.

Impact of Pulse Quenching Effect on Sensitive Area at Advanced Technologies

2013 ◽  
Vol 392 ◽  
pp. 693-696
Author(s):  
Wen Tao Xu ◽  
Yang Guo ◽  
Yan Kang Du
Keyword(s):  
Computer Aided Design ◽  
Three Dimensional ◽  
Sensitive Area ◽  
Isolation Technique ◽  
Quenching Effect ◽  
Advanced Technologies ◽  
Computer Aided ◽  
Simulation Results ◽  
Aided Design ◽  
The Impact

The impact of pulse quenching effect on the sensitive area is evaluated by using three-dimensional technology computer-aided design (TCAD) numerical simulation. Simulation results present that the pulse quenching effect could effectively reduce the sensitive area of PMOS transistors. By adopting the off-state gate isolation technique, the sensitive area is further reduced.

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