Scanning Electron Microscopic Investigations of the Shape of Toothbrush Filaments with Various Brushing Techniques II. The scond and the worst cases of plaque removal

Using 30 second-year students of the Matsumoto Dental College. School of Dental Hygiene as subjects, we performed investigations on toothbrush filament shape changes using 4 test toothbrushes and 4 different brushing techniques over 2 weeks periods. Also, observation by scanning electron microscopy was done for the toothbrushes which yielded the second and the worst effectiveness of plaque removal. The results were as follows: 1. The round-cut filament was worn semispherically or triangularly when using the rolling and Stillman techniques. Also, the round-cut and moving areas of the toothbrush body were worn significantly with the rolling and Stillman techniques. 2. The ditches at the filament edge were not as deep after two weeks of using the Bass and scrub techniques. There were deep ditches and scratches on the edge and center area of the filament with the rolling and modified Stillman techniques

Light and Electron Microscopic Studies of Microcalcifications Appearing in Monomorphic Adenomas

Microcalcifications appearing in two cases of monomorphic adenomas were studied histopathologically, electron microscopically, and electron-microanalytically. One case was basal cell adenoma that occurred in a 56-year-old man and the other was canalicular adenoma in a 71-year-old woman. The calcified granules were observed both in the lumina formed by the tumor cells and in the stromal tissues. The surroundings of the granules were stained by alcian blue and showed a sulfur peak by EPMA. These facts suggest that the surroundings contain sulfated glycosaminoglycans and that sulfur has a significant role in the mechanisms of pathological calcification as well as physiological calcification

Second harmonic generation in gallium phosphide photonic crystal nanocavities with ultralow continuous wave pump power

We demonstrate second harmonic generation in photonic crystal nanocavities fabricated in the semiconductor gallium phosphide. We observe second harmonic radiation at 750 nm with input powers of only nanowatts coupled to the cavity and conversion efficiency $P_{\rm out}/P_{\rm in, coupled}^2 = 430$. The large electronic band gap of GaP minimizes absorption loss, allowing efficient conversion. Our results are promising for integrated, low-power light sources and on-chip reduction of input power in other nonlinear processes

幼若永久歯小窩裂溝の清掃に関する研究 第2報 EMPAによる裂溝内の元素分析について

The application of fissure sealants have been highly appreciated to prevent the development of caries in immature permanent teeth such as first molars immediately after their eruption. However, the sealant often breaks and peels off due to the insufficient cleansing of the surface and pits and fissures of the teeth. We newly developed diamond fixed scratch point (DFSP) for the cleansing of pits and fissures of immature permanent teeth. In this study we aimed to have good prognosis of the condensation of fissure sealant and to suppress the progress of early fissure caries, and made a comparison of this method with conventional methods using brushcone and air-flow in term of the components of fissure debris after cleansing. The effects of cleaning for the three cleaning methods were examined comparatively by usting EMPA. The results obtained were as follows: 1. It was difficult to remove the contents in deep narrow fissures of types I and IK by the methods using brushcone or air-flow. Cleansing effect could not be recognized in the narrow base, for debris and organic residue were found. 2. DFSP developed by authors removed all of the organic debris in the fissures to result in excellent cleansing effect. 3. It was confirmed that extremely mild mechanical cleansing by use of DFSP brought good cleansing effect in deep narrow fissures which seemed to be unable to be cleansed sufficiently by the conventional methods

Scanning Electron Microscopic Investigations of the Shape of Toothbrush Filaments with Various Brushing Techniques I. The most effective case of plaque removal

Using 30 second-year students of the Matsumoto Dental College, School of Dental Hygiene as subjects, we performed investigations on toothbrush filament shape changes while using 4 test toothbrushes and 4 different brushing techniques over 2 week periods. Also, observation by scanning electron microscopy was done for the toothbrush which yielded the best plaque removal. The results were as follows: 1. The edge of the brush filament was worn almost rectangularly along the longitudinal axis after 2 weeks of using the Bass and scrub techniques. 2. The filament edge tended to become sharper with the rolling and modified Stillman techniques. The round-cut and moving area of the toothbrush body were worn significantly using the rolling and modified Stillman techniques. 3. The toothbrush filaments with every brushing technique were worn significantly. Deep ditches, scratches and peeling were frequently observed with the rolling and modified Stillman techniques

Demonstration of the operation principles of intermediate band solar cells at room temperature

In this work we report, for the first time at room temperature, experimental results that prove, simultaneously in the same device, the two main physical principles involved in the operation of intermediate band solar cells: (1) the production of sub-bandgap photocurrent by two optical transitions through the intermediate band; (2) the generation of an output voltage which is not limited by the photon energy absorption threshold. These principles, which had always required cryogenic temperatures to be evidenced all together, are now demonstrated at room temperature on an intermediate band solar cell based on InAs quantum dots with Al0.3Ga0.7As barriers