OBJECTIVES Nanofilled composite resins are claimed to provide superior mechanical properties compared with microhybrid resins. Thus, the aim of this study was to compare nanofilled with microhybrid composite resins. The null hypothesis was that the size and the distribution of fillers do not influence the mechanical properties of surface roughness and wear after simulated toothbrushing test. ...

BACKGROUND This study aimed to evaluate the effect of dental prophylaxis on the surface gloss and roughness of different indirect restorative materials for computer-aided design/computer-aided manufacturing (CAD/CAM): two types of CAD/CAM composite resin blocks (Shofu Block HC and Estelite Block) and two types of CAD/CAM ceramic blocks (IPS Empress CAD and Celtra DUO). MATERIAL AND METHODS Af...

In this experimental study, three TiB2/Al metal matrix composites (MMCs) with 40 μm in mean size were produced using a melt stirring squeeze casting route. Test was carried out to find the parameters influencing surface roughness (Ra) and material removal rate (MRR) on machining the TiB2 reinforced Al-6063 composite materials. The orthogonal array, the signal-to-noise ratio, and analysis of var...

PURPOSE The use of appropriate instruments to clean surfaces with minimal change, is critical for the successful maintenance of a dental implant. However, there is no consensus about the type and methodology for such instruments. The aim of this study was to characterize changes in the roughness of titanium surfaces treated by various scaling instruments. METHODS Thirty-seven identical disks ...

Background and Aim: It has been commonly believed that, denture cleansers have detrimental effects on the surface structure of denture base materials. The purpose of this study was to evaluate the effects on surface roughness of 4 different commercially available chemical cleaning agents (Polident, Corega Tabs, Fittydent, Efferdent) and sodium hypochlorite on the denture base materials. Materia...

This in vitro study determined the surface roughness (Ra) and absolute gloss (AG) values for 2 resin composites: a microhybrid and a microfill. Eight groups (n = 4) of each resin composite were prepared, along with 4 controls (Mylar strip) for the 2 resin composites. After finishing with a medium polishing disc, the specimens from each resin composite material were subjected to 7 polishing proc...

Many Wire-EDM machines have adopted the pulse generating circuit using low power for ignition and high power for machining. However it is not suitable for finishing process since the energy generated by the high voltage sub-circuit is too high to obtain a desired fine surface, no matter how short the pulse on time is assigned. For the machine used in this research, the best surface roughness Ra...

surface roughness is one of the most important parameters that plays very critical role in determining the quality of engineering components. a good surface quality resulting in improve of fatigue strength, corrosion and wear resistance of the workpiece. on the other hand, increasing cutting speed and decreasing time of machining are desirable for manufacturers in order to reduce costs and incr...

in this paper, a new non-contact ultrasonic abrasive finishing mechanism is designed and fabricated. this mechanism combines the function of ultrasonic vibrations and the magnetic abrasive finishing (maf) process. a permanent magnet which is mounted on a horn has been used as the processing tool. this polishing tool is vibrated at an ultrasonic frequency with piezo-electric actuators. ultrasoni...

This study was an evaluation of measuring strategies using a handheld 2D profiler for quality control of finish milled tool steel with regard to surface roughness. A selection of ball nose end mills in combination with two different tool steels (hardness 39 and 47 HRC) were used to manufacture the surfaces that were to be measured. It was found that using an appropriate measuring strategy it is...