Using a smartphone three dimensional scanning application (Polycam) to three dimensionally print an ear cast: A technique.

This technique describes the use of a smartphone application for scanning an ear for 3-dimensional (3D) printing of an auricular prosthesis cast. The intact ear was scanned by using a smartphone and a 3D scan application (Polycam). The standard tessellation language (STL) file of the 3D data was used to produce a mirror image of the ear, which was sent to the 3D printing center where a resin cast was printed. This technique is harmless for the patient compared with radiological imaging methods, more comfortable, and cost-effective and is straightforward for the maxillofacial prosthodontist.

Effects of ceramic type, connector dimension, and thermomechanical-aging on the fracture resistance and fit of CAD-CAM produced inlay-retained fixed partial dentures.

The purpose of the present study is to evaluate the fracture resistance and the fit of CAD-CAM produced inlay-retained fixed partial dentures. Eighteen experimental groups were generated according to different CAD-CAM ceramic materials (zirconia, lithium disilicate, and zirconia-reinforced lithium silicate), different connector dimensions (12, 14, and 16 mm2), and application of thermomechanical-aging (1,200,000 cycles of cyclic loading with simultaneous thermal cycling). Gap values of thermomechanically-aged groups were measured by using periapical radiographs. Then, the specimens were tested for fracture resistance and failure types were examined. The results were statistically analyzed (α=0.05). Higher gap values were observed after aging. Zirconia showed the highest fracture resistance values among the most of the experimental groups. In non-aged groups, the most frequent failure type was decementation in zirconia group. In the aged groups, the most frequent failure type was molar connector fracture. Thermomechanical-aging increased the gap values and decreased the fracture resistance values.

Effect of plasma treatment on the peel bond strength between maxillofacial silicones and resins.

The study aimed to investigate the effects of surface treatments, including plasma, on the peel bond strength between two maxillofacial silicones and two resins with and without thermocycling. Forty-eight experimental groups (n=10) were generated incorporating the two different resins (auto-polymerizing acrylic resin and light-curing urethane dimethacrylate resin [AR and LR, respectively]), two different silicones (M511 and Z004), aging (thermocycled/no thermocycling), and six different surface treatments, including polishing, grinding, polishing+argon plasma, polishing+oxygen plasma, grinding+argon plasma, and grinding+oxygen plasma. Surface topography of a specimen from each surface treatment group was examined by atomic force microscopy. After surface treatments, silicones were polymerized. The peel bond strength values of the control and thermocycled groups were determined. Atomic force microscopy showed that surface topographies of the ground specimens were irregular. Polished specimens showed higher peel bond strength than ground specimens. Plasma application appeared to have improved the bond strength between the resins and silicones.