We report on a distance control system for low-temperature scanning near-field optical microscopy, based on quartz tuning fork as shear force sensor. By means of a particular tuning fork-optical fiber configuration, the sensor is electrically dithered by an applied alternate voltage, without any supplementary driving piezo, as done so far. The sensitivity in the approach direction is 0.2nm, and...

background: restoration of anterior primary teeth with severe caries lesion is a big challenge. the aim of this study was to compare the fracture resistance of three types of post, including composite resin, customized quartz fi ber and prefabricated glass fi ber in restoration of severely damaged primary anterior teeth. materials and methods: sixty extracted human primary maxillary incisors we...

Purpose To evaluate the degree of conversion (DoC) self-adhesive resin luting cements when irradiated through different fiber post lengths. Methods A total 60 teeth were sectioned to achieve lengths 4 mm, 7 and 10 while posts trimmed give 3 6 9 mm Post space was created accommodate 1 cement apically. Two (Multilink Speed RelyX U200) used. four cycles 20 s irradiation done with an attenuated ref...

OBJECTIVES To determine the retentive strength and failure mode of undercut composite post, glass fiber post and polyethylene fiber post luted with flowable composite resin and resin-cement. MATERIALS AND METHODS Coronal parts of 120 primary canine teeth were sectioned and specimens were treated endodontically. The teeth were randomly divided into 6 groups (n = 20). Prepared root canals recei...

[1] The most energetic planetary collisions attain shock pressures that result in abundant melting and vaporization. Accurate predictions of the extent of melting and vaporization require knowledge of vast regions of the phase diagrams of the constituent materials. To reach the liquid-vapor phase boundary of silica, we conducted uniaxial shock-and-release experiments, where quartz was shocked t...

background and aims. various factors influence the interfacial bond between the fiber posts and root canal dentin. the aim of the present study was to evaluate the effect of pre-warming of resin cement on the push-out bond strength of fiber posts to various segments of root canal dentin. materials and methods. in this in vitro study, 40 single-rooted human premolars were decoronated and underwe...

We demonstrate gas detection based on evanescent-wave photoacoustic (PA) spectroscopy with tapered optical fibers. Evanescent-field instead of open-path absorption is exploited for PA generation, and a quartz tuning fork is used for PA detection. A tapered optical fiber with a diameter down to the wavelength scale demonstrates detection sensitivity similar to an open-path system but with the ad...