Fixture synthesis addresses the problem of fixture-elements placement on workpiece surfaces. This article presents a novel variant simulated annealing (SA) algorithm called declining neighborhood (DNSA) specifically developed for fixture synthesis. The objective is to minimize measurement errors in machined features induced by misalignment at locators-workpiece contact points. systematically ev...

objectives : the purpose of this in vitro study was to compare the marginal adaptation and fracture resistance of a zirconia-based all-ceramic restoration with two preparation designs. materials and methods: twenty-four mandibular premolars were randomly divided into two groups (n=12); the conventional group received a peripheral shoulder preparation and the modified group received a buccal sho...

objectives : marginal adaptation is important for long-term success of full-coverage restorations. the aim of this study was to determine the effect of porcelain firing cycle and different thicknesses of ips e.max core on marginal accuracy of all-ceramic restorations. materials and methods : a standard stainless steel die with 0.8 mm classic chamfer finish line and 10° taper was used in this in...

during dental education, dental students learn how to examine patients, make diagnosis, plan treatment and perform dental procedures perfectly and efficiently. however, progresses in computer-based technologies including virtual reality (vr) simulators, augmented reality (ar) and computer aided design/computer aided manufacturing (cad/cam) systems have resulted in new modalities for instruction...

Background and Aim: Chairside computer-aided design/computer-aided manufacturing (CAD/CAM) systems have become considerably more accurate, reliable, efficient, fast, and prevalent since 1985 when CEREC was introduced. The inceptive restorative material option for chairside CAD/CAM restorations was limited to ceramic blocks. Today, restorative material options have been multiplied and include me...

In support of rapid-response manufacturing, we propose a new technique for automated design and fabrication of fixture and gripper tooling for mechanical assembly. Our technique utilizes geometric computations on CAD part descriptions to derive form and force closure tooling. In addition, we invoke rapid prototyping technology to fabricate the computed tooling directly from the derived CAD desc...

background: the aim of this study was to determine the microtensile bond strength (μtbs) of ceramic and composite computer aided design‑computer aided manufacturing (cad‑cam) blocks bonded to dentin using different adhesive strategies. materials and methods: in this in vitro study, 30 crowns of sound freshly extracted human molars were sectioned horizontally 3 mm above the cementoenamel junctio...

Jigs and fixtures were brought to the world of machining, bringing a variety practical purposes. The concept enables rapid mass production same product. Thus, company will streamline manufacturing process for each component boost productivity. At times, machining operation was carried out entirely by machine, without jigs fixtures. As result, created expedite drilling process. project's objecti...