Dental preparations require a high degree of precision. The goal of the study was to                                                                                                        examine the surface design from the use of different drives.                                                                                             The study was conducted under standardized, clinically simulated conditions. The test subjects prepared surfaces on CEREC VITABLOCS MARK II using three drives that facilitated and did not facilitate contact grinding. In addition, various diamond rotary instruments were used. The waviness parameter Wt (wave depth) showed significantly smaller values for the drives that enabled contact grinding than for the older turbines that did not. No significant differences were found in the comparison of the results for the GENTLEforce 7000 B turbine and the micromotor with speed-enhanced contra-angle piece. The parameter RSm (groove width) showed the highest values for the older turbines.                                                                                                           As relatively large convergence angles are achieved in the dental preparations with patients, the significant differences in waviness on the surfaces have little clinical importance.

Statement of problem The 2-step putty and wash impression technique is commonly used in fixed prosthodontics. However, cutting sluiceways to allow the light-body material to drain is time-consuming. A solution might be the use of a spacer foil. Purpose The purpose of this study was to evaluate the influence of spacer foil on the margin reproduction and dimensional accuracy of 2-step putty and wash impressions. Material and methods Two methods of creating space for the wash material in a 2-step putty and wash impression were compared: the traditional cutout technique and a spacer foil. Eleven commercially available combinations of silicone impression materials were included in the study. The impressions and the cast production were carried out under standardized conditions. All casts were measured with a 3-dimensional (3D) coordinate measuring machine. Preparation margin reproduction and the diameters and spacing of the stone cast dies were measured (α=.05). Results The 2 methods showed significant differences (P<.05) in the reproduction of the preparation margins (complete reproduction cutout, 90% to 98%; foil, 74% to 91%). The use of a foil resulted in greater dimensional accuracy of the cast dies compared to the cutout technique. Cast dies from the cutout technique were significantly smaller than the metallic original cast (cutout median, 4.55 mm to 4.61 mm; foil median, 4.61 to 4.64). Spacing between the dies revealed only a few additional significant differences between the techniques. Conclusions When spacer foils were used, dies were obtained that better corresponded to the original tooth.

Mandibular tumor resection can lead to a mandibular segmental defect. LaserCUSING (R) is used to produce a mandibular implant, designed to be identical to the shape of the mandibular defect. Novel microrough surfaces result from this generative technology. In the current study, the behavior of human osteoblasts on untreated laser-cused titanium specimens or on specimens conditioned with different blasting agents was analyzed. The conditioning of these specimens resulted in surfaces with graded roughness. White light confocal microscopy and single-cell force spectroscopy were used to characterize the surface of the specimens and to quantify the initial adhesion of primary human osteoblasts to the specimens, respectively. Furthermore, cell growth, viability, apoptosis as well as mineralization of the specimens were analyzed over a time-period of 2 months. Compared to specimens that were treated with blasting agents, untreated specimens had the highest surface roughness. Quantitative SCFS measurements demonstrated that the adhesion of human primary osteoblasts was the highest on these specimens. Additionally, the untreated specimens allowed the highest number of osteoblasts to colonize. Mineralization studies showed increasing calcium and phosphor elemental composition for all specimen series. It can be concluded that untreated laser-cused titanium specimens are superior to promote the initial adhesion and subsequent colonization by osteoblast cells. (c) 2013 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 102A: 1422-1430, 2014.