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A Study of the Cleaning Methods on Pits and Fissures of Immature Permanent Teeth Part-II Elementary analysis of the contents in fissures by using EMPA
Get PDFapplication/pdfThe 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.journal articl
感染防止対策としての診療用エプロンの使用 第1報 素材におよぼす各種薬液の影響について
Get PDFapplication/pdfThe operating aprons that have been adopted as an infection control measure are subject to fiber discoloration, fiber fraying, and the appearance of holes. To investigate the causes of these problems, this experiment was carried out to determine what effects various fluids used medicaly have on different cloth materials. Cloth samples made of 100% cotton, 65% polyester/35% cotton, and 80% polyester/20% cotton were used as the experimental cloth. As the experimental fluids, 0.9% sodium chloride, 70% alcohol, 1.5% hydorogen peroxide, 10% sodium hypochlorite, 3% sodium hypochlorite, 0.1% acrinol solutions were used. Tap water was used as the control fluid. The fluid was dropped on to each cloth sample and allowed to dry. The samples then were sterilized in an autoclave and cleaned. The changes of the cloths were investigated. The results were as follows: 1) Sodium hypochlorite solution had the greatest influence in causing discoloration on cloth of all compositions. 2) Sodium hypochlorite solution caused fraying of fibers and holes in 100% cotton cloth regardless of the weave consistency. 3) The alcohol, hydrogen peroxide and acrinol solutions also caused discoloration in cloth of each type. 4) The fibers of the 100% cotton cloth tended to become more fragile with repeated sterilizations. 5) Polyester mixed cloth, even though it was subject to discoloration, seemed to be quite durable as it showed no fraying of fibers or holes.journal articl
Effect of Corticotomy on Maxillary Anterior Bone Segment Retraction Induced by Orthopedic Force
Get PDFapplication/pdfThe dry skulls of two adult female Japanese macaques were used in this study of bone strains produced by corticotomy combined with orthopedics. The directions and magnitudes of the principal strains were measured using an eight-pair triaxial strain gauge rosette. While compressive strains were seen in the control study (orthopedic force alone before corticotomy), tensile strains were seen in the experimental study (orthopedic force after corticotomy) on the frontzygomatic suture, the lateral side of the zygomaticomaxillary suture of the zygomatic bone, and on the maxillary bone. Corticotomy, combined with the posterior transfer of the anterior segment, had the following effects : in the control study, traction was diffused though the maxillofacial structures, while in the experimental study, it did not readily diffuse because the compact bone was separated. This resulted in favorable conditions for the posterior transfer of the anterior maxillary segment between the maxilla proper and the maxillary alveolar bone which are connected only by trabecular bone. These results demonstrate the usefulness of combining a corticotomy with retraction of the maxillary anterior segment by orthopedic forces. A clinical case of Class II malocclusion is presented to illustrate what can be accomplished with treatment by corticotomy. The treatment objectives were achieved with improvement in the patient's profile and in the function and esthetics of the dentition.journal articl
Eruption State of Mandibular Third Molar and Morphology of Mandible
Get PDFapplication/pdfRecent studies have indicated that even in cases in which the existence of tooth germs are observed, third molars cannot perfectly erupt because there is too little space for eruption in the distal end of the 2nd molar, and that cases of impaction or semi-impaction are increasing. The purpose of this study was to compared the morphological variation of the mandible as the mandibular corpus and the mandibular ramus among three groups: a group of full impaction of the third molar in the mandibular dental arch (A group), a group of semi-impaction (B group), and a group of full eruption (C group). The following results were obtained. 1) Concerning the measurements representing distance: R (the width of the mandibular ramus), was significantly longer in group A while it was shorter in group C. M (total length of the mandible), C (length of the mandibular corpus) and the distance between Cd and Gn were all significantly longer in group C than in group A. 2) Concerning the measurements representing angles, the Go angle was significantly larger in group C than in group A. 3) All the measurements in group B approached the median value of those of group A and group C. It was suggested that there was no impaction of the mandibular third molar observed due to the reduction of the mandible, and that the eruption of the mandibular third molars appears to be affected by the growth and change in the mandibular corpus and the mandibular ramus and/or the change in the Go angle.journal articl
カエル舌水受容器の化学 修飾2.DEP, AIおよびHNBBの作用
Get PDFapplication/pdfOur previous work demonstrated that histidase and tryptophanase applied to the single fungi form papilla preparation dissected from the frog tongue inhibited irreversibly the response to the stimulating solution containing 5mM CaCl_2 and 100mM NaCl (Ca response) without inhibiting the response to 0.3M NaSCN and 0.5M NaCl (Na response) in some preparations, suggesting that histidine and tryprophane residues of receptor molecules are essential for the initiation of the transduction process of the Ca response. To ascertain the importance of histidine and tryptophane residues, we studied chemical modifications of histidine residues by diethylpyrocarbonate (DEP), of tyrosine residues by acetylimidasole (AI) and of tryptophane residues by 2-hydoxy-5-nitrobenzylbromide (HNBB). DEP and HNBB inhibited the Ca response irreversibly without inhibiting the Na response at low concentrations. These results suggest that histidine and tryptophane residues play an essential role in the initial process of the transduction of the Ca response in the water receptor of the frog.journal articl