Efficient Intersection Computation of the Bezier and Hermite Curves with Axis Aligned Bounding Box

Cubic parametric curves are used in many applications including the CAD/CAM systems. Especially the Hermite, Bezier and Coons formulations of a cubic parametric curve are used in E2 and E3 space. This paper presents efficient algorithm for the intersection computation of a cubic parametric curve with the Axis Aligned Bounding Box (AAB Box). Usual solution is to represent the cubic curve by a polyline, i.e. actually by sampled points of the given curve. However, this approach is dependent on the sampling frequency and can lead to problems especially in CAD/CAM systems and numerically controlled machines use.

CAD/CAM in Restorative Dentistry

Computers have had a huge impact on the dental place of work and dental exercise major to huge adjustments in communication, financial accounting, and administrative functions. Computerized systems have greater currentlygenerated developing variety of software program for the delivery of affected character treatment. Digital effect systemsand chairside CAD/CAM systems offer opportunities to mix virtual impressions and entire contour restorations withinside the dental place of work. Systems depend on single picturegraph and video cameras to report the digital file that is the foundation for an accurate outcome. This article gives key elements of automatic generation using the CAD/CAM process. CAD/CAM technique appears to be the most common technique currently available; this is fast, easy and maintains time. CAD/CAM systems are variable; therefore, using the right gadget with a logical approach for treating patients are quite mandatory. Keywords: CAD/CAM systems

Spatial resolution of an integrated C4+CAM photosynthetic metabolism

C4 and CAM photosynthesis have repeatedly evolved in plants over the past 30 million years. Because both repurpose the same set of enzymes but differ in their spatial and temporal deployment, they have long been considered as distinct and incompatible adaptations. Remarkably, Portulaca contains multiple C4 species that perform CAM when droughted. Spatially explicit analyses of gene expression reveal that C4 and CAM systems are completely integrated in P. oleracea, with CAM and C4 carbon fixation occurring in the same cells and CAM-generated metabolites likely incorporated directly into the C4 cycle. Flux balance analysis corroborates the gene expression and predicts an integrated C4+CAM system under drought. This first spatially explicit description of a C4+CAM photosynthetic metabolism presents a new blueprint for crop improvement.

Artificial intelligence in periodontics – A dip in the future

BACKGROUND: Artificial intelligence is a relatively newer technology in the field of medical world. This science uses the machine – learning algorithm and computer software to aid in the diagnostics in medical and dental fields. It is a huge talking point in the field of technology which is spreading it’s wings in all possible sectors at a great speed. This field covers solutions from coaching solutions to diagnostics in medical field covering under the umbrella of all what can be achieved by machine and deep learning. CONTENT: In dentistry, artificial intelligence is creating a revolution in all sections from collection of data, creating algorithms for orthodontic procedures, diagnostic records in the aspect of radiographic data, three dimensional scans and cone beam computed tomography, CAD CAM systems for restorative and prosthetic purposes. Similarly continuous research is being done in the field of periodontics in terms of measuring bone loss, amount of plaque present and much more. CONCLUSION: The field of artificial technology with its varied applications will change the face of dentistry in the upcoming times. Artificial intelligence with its application of machine learning will change the face of dentistry in future.

Effectiveness of Automatic CAM Programming Using Machining Templates for the Manufacture of Special Production Tooling

The paper presents the methodology and implementation of original Automatic CAM programming using machining templates (ACPUT) dedicated to manufacturing special technological tooling. The development of ACPUT was inspired by the observation that although modern computer-aided design (CAD) / computer-aided manufacturing (CAM) systems can automatically create CAM programs, their universality makes them both difficult to use and inefficient because the programs created this way often contain errors. The presented programming procedure includes the development of specific machining templates based on technological knowledge gathered in a specially prepared database. These templates are dedicated to a group of parts characterized by the similarity of their geometric features. ACPUT makes it possible to reduce(in comparison to traditional CAM programming) the time required to develop a machining program, thereby positively impacting the total cost of tooling production. The paper aims to present results of testing the effectiveness of the use of ACPUT by technicians with different levels of experience (expert and beginner). The tests were carried out on special tooling - assembly equipment for plastic pipes, and compared program preparation time, machining time, and production costs.

Controlling turning contouring of shaped parts

The machining of contoured shaped surfaces of parts with a circular cross-section is executed on CNC lathes using control programs. All known CAM systems offer canned cycles for such surfaces. In most cases, it is recommended to use G71, G72 and G73 canned cycles for roughing contouring. The aim of the study is to analyze the cutting processes in roughing and finishing and to assess their influence on the surface quality of the part. A modeling technique is proposed, which is based on the use of an original application soft that allows simulating all machining cycles with fixing the results in the form of oscillograms of changes in the depth of cut. Comparative analysis of the results allows you to choose the most acceptable machining cycle for a specific profile of the contour of the part. The developed program also makes it possible to obtain the predicted accuracy of machining along the entire contour, which may arise as a result of technological heredity. In addition, the array of data on cutting depth obtained during the simulation, which is the main disturbance of the process, allows one to design the law of control of the cutting mode, for example, on the feed, which will lead to the stabilization of the cutting process. Анотація. Обробка контурних фасонних поверхонь деталей, що мають круглий поперечний переріз, виконується на токарних верстатах з ЧПУ по керуючим програмами. Всі відомі САМ-системи пропонують стандартні цикли для обробки таких поверхонь. У більшості випадків рекомендується застосовувати стандартні цикли чорнової контурної обробки G71, G72 і G73. Метою дослідження є аналіз процесів різання в чорновий і фінішної обробки і оцінка їх впливу на якість поверхні деталі. Порівняльний аналіз результатів дозволяє вибрати найбільш прийнятний цикл обробки для конкретного профілю контуру деталі. Розроблена програма також дозволяє отримати прогнозовану точність обробки по всьому контуру, яка може виникнути в результаті технологічної спадковості. Крім того, отриманий під час моделювання масив даних по глибині різання, який є головним обуренням процесу, дозволяє спроектувати закон управління режимом, наприклад, з подачі, які призведе до стабілізації процесу різання.

Digital Smile Design : Predictable Results

Increasing aesthetic preferences and technological changes in dentistry have been planned towards time, resulting in predictable, more aesthetic and more functional results. Firstly, the development of digital dentistry, especially the CAD/CAM systems, following these developments, the ability to make smile designs with the effect of digitalization in anterior restorations led to the emergence of reliable and more guaranteed restorations for both the patient, dentist and dental technician. This review summarizes the information and offers suggestions with features to be considered in digital smile design and digital smile design softwares.

Marginal and Internal Precision of Zirconia Four-Unit Fixed Partial Denture Frameworks Produced Using Four Milling Systems

Background: CAD/CAM systems enable the production of fixed partial dentures with small and reproducible internal and marginal gaps. Purpose: The purpose of this study was to evaluate the reproducibility of the marginal and internal adaptations of four-unit fixed partial denture frameworks produced using four CAD/CAM systems. Materials and Methods: Prepared dies of a master model that simulated the loss of the first left molar were measured. Fifteen frameworks were manufactured using four CAD/CAM systems (A–D). The internal fit was determined by the replica technique, and the marginal gap was determined by microscopy. ANOVA was carried out to detect significant differences, and the Bonferroni adjustment was performed. The global level of significance was set at 5%. Results: The mean gap size ranged from 84 to 132 µm (SD 43–71 µm). The CAD/CAM systems showed significant variance (p < 0.001), and system A (VHF) showed the smallest gaps. The smallest gaps for each system were in the molar part and in the marginal region of the frameworks (p < 0.001). Conclusions: The CAD/CAM systems showed significantly different gap sizes, particularly between premolars and molars and among the marginal, axial and occlusal regions. All of the systems are suitable for clinical application.