Kanagawa shigaku. The Journal of the Kanagawa Odontological Society最新文献

The acid-resistance of the tooth surface is strengthened to form noncrystal lanthanum fluoride on its surface by the two-step treatment (F-La treatment) with acidulated-phosphate fluoride and lanthanum chloride solutions as previously reported by Fujiwara, Negishi, Miyagi et al. This study has been made to examine some clinical applications of the treatment. The acid-resistance effect and the actual condition of the F-La treatment were investigated on the extracted human deciduous dentin. Analysis was made using the electron probe X-ray microanalyzer before and after the acid solubility test. The results were as follows: 1) With F-La treatment, the acid-solubility of deciduous tooth dentin was reduced to about one-third of that without treatment, and to about two-third compared both with F-treatment and with diamine silver fluoride application. 2) Applications of 3 to 5 minutes with F and 3 minutes with 0.5 to 1.0% La sufficed for this F-La treatment. 3) An etching procedure was not necessary previous to the treatment in contrast with the application to the enamel. 4) Fluorine and lanthanum penetrated up to approximately 10 microns from the dentin surface with this treatment. Even after the acid-solubility test, a sufficient quantity of the stated chemicals remained, thus protecting the tooth substance. 5) The acid-solubility of the deciduous dentin was higher than that of the deciduous enamel. After the F-La treatment, however, the former diminished more markedly than the latter. Based on these experimental results, one can confirm the fact the chemical reactivity of the deciduous dentin is higher than that of the deciduous enamel.

The best method of preventing HBV is accurate perception on the part of the patient. There is a need for sufficient care regarding patient blood with HBsAg (+), HBeAg (+) and HBc high-antibody titer. The following is a report on a follow-up survey regarding antibody titer following dosages of HBIG 2 V and 1 V and administration of a vaccine along with dosage of HBIG 1 V. 1. Dosage of HBIG 2V: (Female) Antibody titer was recognized two days following dosage. It continued for two weeks and disappeared after four weeks. (2) (Male) Antibody titer was recognized one day following dosage but disappeared after two weeks. 2. Dosage of HBIG 1 V: (Female) Antibody titer (-) was recognized two days after dosage and nine days after dosage. It continued for about one month and disappeared after five months. 3. Administration of three vaccines and dosage of HBIG 1 V: (Female) Antibody titer was recognized two days after HBIG 1 V dosage and continued for 18 days but disappeared after three months. Antibody titer was recognized again after about eight months and showed signs of continuing for 13 months.

In this study a comparison was made in determining morphometrical changes in bone utilizing standard dental radiographic technique and dental xeroradiography. In terms of energy intensity, results demonstrated that spectrum analysis is consistent with visual evaluation and useful as a technique for objective evaluation of changes in bone. Changes in trabecular patterns were experimentally reproduced using quantitative determinations of calcium and phosphate. The relation between radiographic changes in bone associated with decalcification and variations in bone mineral content actually eluted from a particular site were examined. Changes in radiographic contrast and morphometry are important as indicators in radiographic interpretation, and their effects on visual evaluation of the radiograms were also studied. Also evaluated was the usefulness of the technique of using a spectrum analyzer to physically analyze the energy intensity distribution changes in bone. The findings in this study indicate that changes in both contrast and morphometry provide indicators for radiographic interpretation in DF, and that changes in contrast play a more dominant role with increasing bone density. It was also demonstrated that radiographic interpretation in DXR depends on morphometrical changes rather than changes in contrast as a major indicator. Since there was no difference in the efficiency of visual detection between DF and DXR, the use of DXR appears more beneficial in view of lower radiation exposure. When the detectability was 80%, actual variations in bone mineral content ranged from 24% to 38%. Thus, it may be possible to visually identify much smaller variations in bone mineral content on radiograms by using additional indicators such as pattern recognition and marginal changes of the lesion.

The effect of matrix components extracted Bovine periodontal ligament (PDL) on cell proliferation and alkaline phosphatase activity of cultured human periodontal ligament fibroblast (HPLF) were examined in order to understand the cell-tissue interaction of periodontal ligament. Bovine PDL tissue was sequentially extracted with 0.05 M Tris HCl buffer, pH 7.4, containing 1M NaCl or 4M GdmCl. After seeding 24 hours, the cultured HPLF were exposed to the extracts for two through eight days. Nine days after seeding, HPLF indicated four times high activity on ALP and 1.6 times the amount of total protein than those of control (without extract), while DNA synthesis increased only 1.2 times. On the contrary, the NaCl extract depressed the ALP activity of HPLF. The GdmCl extract enhanced both the total protein and ALP activity in dose-dependently. The ALP increasing activity of GdmCl extract on HPLF is stable to heat (78 degrees C, 20 min) and collagenase treatment but partially inactivated by trypsin digestion. Since the GdmCl extract also induced colony formation of NRK-49F cell in soft agarose, it was suggested that the extract contain EGF and TGF-beta like factor. Molecular size of this factor was estimated as 20-50Kd using Sepharose CL-6B gel chromatography. Furthermore, this factor from Sepharose CL-6B were separated into two forms by ion exchange CM-Sepharose column chromatography. Purified preparation from reversed phase column chromatography contained 14Kd, 15Kd, 17Kd, 20Kd, 28Kd40Kd, and 46Kd components on SDS-PAGE. This factor may accumulate in extracellular matrix, and may play a role of cell-tissue interaction and homeostasis in periodontal ligament.

It is well documented that uptake of various trace elements take place during tooth development. The purpose of this experiment was to analyze the uptake amount of these various trace elements, in particular Cd, Zn, Pb and Cu throughout the tooth germ formation all the way up to the eruption stage. Bovine permanent tooth germs were used in this experiment. Instead of the conventional morphologic stages, further subdivision into eight groups were employed. The resultant findings were as follows: 1) Uptake of Cd and Zn were verified during the root development to early tooth eruption stage in enamel. Meanwhile, for dentin, the uptake was corroborated from the root development to the late tooth eruption stage. 2) Uptake of Cu was verified during the late tooth eruption stage in enamel. However, no uptake occurred in dentin in any of the various stages. 3) Uptake of Pb occurred during the late tooth eruption stage in enamel. Meanwhile, in dentin, constant equivalent amount of uptake was seen throughout all of the stages. 4) Quantitative analysis of the Cd, Zn and Pb uptake in both enamel and dentin clearly indicated that enamel showed much higher values. The uptake of Cu was found to be significantly high in the groups of the coronal one-third and the eruption four-fifth groups for enamel. Meanwhile, the crown completion group to the half erupted group showed significantly high values for dentin. Based on the above findings, one can deduce clear correlation between enamel organ development and the uptake of the said various trace elements.

Today, it has been quite important to realize that the esthetic factor the coronal restration is more emphasized in dental practice. It is popular to use porcelain as a dental material for the Coronal restoration and the technique is pretty much stabilized. Because of the color itself and its great affinity to the human body. Mostly used technique is the porcelain fused-to metal crown. However, there are various disadvantages relating to this technique. On the other hand. The electroforming technique has some great characteristics that is producing the complex shape with less difficulty, and the improvement of it's final surface. It also has the ability for reduplication. Overall, metal frame can be constracted on the same working model without a duplication of it. Therefore, it is possible to make the procedure extremely simple. Here, the author has done some experiments with the newly developed electroforming apparatus for constructing the Coronal restoration. The purpose of the experiments are to apply all these great advantages of the system to dental prosthodontics field. One characteristic of the equipment is the diffusion of current distribution by the cathode rotary system. The other one is the circulation of electrolyte for reducing the diffusion layer. Firstly, the author operated the electroposition with Ni on the three different standard models of abutment teeth, in order to determine the possibility of making a metal frame and the relationship between the shape of the abutment teeth and the current. Next experiment was to investigate if it's possible to apply the metal frame, constructed by the apparatus, to porcelain fused-to metal crown by again determining the relationship between the electropositioned metal and the porcelain. The results were obtained as follows. 1. It was possible to construct a metal frame for the porcelain fused-to metal crown by the method. 2. The minimum electroposition time was approximately 35-40 min. with a high current density. 3. The thickness of the metal frame did not effect the current, however it barely effected the shape of the abutment teeth. 4. The tensile strength by shear was approximately 150 kg/cm2. 5. There was no evident that the current has any effects on tensile strength.

Cases of lower unilateral free end defect are the source of many problems in clinical dentistry. The denture design method most commonly used is cross arch stabilization which involves creating a retainer on the side opposite the defect via a bar in order to stabilize the denture and protect the retaining teeth. Almost all research on this method involves experiments using a static load. Moreover, there are few studies that attempt to clarify the relationship between the major connector and the retaining teeth. As a means of clarifying these problems, the authors used the modal analysis method and a vibrometer, both of which have proven effective in general observation of lowr denture dynamics when dynamic force is applied. This allowed them to see the relationship between the metal framework configuration and the retainer in animation and thereby study displacement quantity and damping quantity. The following interesting were obtained. 1. There were four modes detected for fixed vibration on the individual metal frameworks: 500Hz band, 1kHz band 2kHz band and 4kHz band. 2. The dynamics of the individual metal frameworks were as follows: Mode 1 was a rigid body mode in a vertical direction with a fulcrum of angle 54. Mode 2 was a horizontal rigid body mode with a fulcrum of angle 54. Mode 3 was a mixture of a horizontal rigid bode and horizontal bend mode. There was a rolling type mode observed only from the plate type. Mode 4 consisted mainly of a horizontal bend mode. This showed that there were differences among the various modes. 3. Judging from the displacement rate computed at the 500Hz band, the rate of displacement decreases as the thickness and ratio decrease. 4. Judging from linear damping quantity and damping quantity in terms of frequency, the finishing line showed a greater tendency toward resonance. 5. Analysis in terms of vibratory science using modal analysis and octave band analysis hinted at the significance of cross arch stabilization.

The finishing line on a metal framework strengthens the mechanized coupling between the metal and the resin. However, due to extreme variations in metal thickness on the finishing line section, stress tends to concentrate in certain areas during function, making the finishing line an area with frequent denture breakage in a clinical setting. The author used modal analysis to clarify the manner in which stress concentrates on the finishing line. The activity observed was them used to determine the influence on the activity of the finishing line from factors such as differences in the finishing line angle, differences in the major connector and differences in the skeleton configuration. The following results were obtained. 1. Regarding the resonance frequency of the test materials, modes 6-7 were detected. 2. Displacement in the periphery of the finishing line and for the major connector in each mode was extremely small compared to the amount of downward pressure on the mucose and the labio-lingual displacement of natural teeth. 3. The activity of the test materials between 200Hz and 300Hz was the rigid body mode for the entire test material using as a fulcrum the rest on the side where vibration was applied. There was resonance detected in the test materials between 1 kHz and 6 kHz. 4. It is believed that there is less concentration of stress on a palatal bar when the angle of the finishing line is an obtuse angle. 5. It was difficult to determine any effect on activity due to the difference in the angle of the finishing line on a palatal bar, lingual bar and lingual plate. 6. The skeleton configuration was more bended the lattice type than the ladder type.

The passive Ca2+ efflux pathways in skeletal sarcoplasmic reticulum (SR) vesicles include the efflux through a Ca2+ channel and a passive leak parallel to the channel and the pump. It is known that caffeine stimulates Ca(2+)-induced Ca2+ release. To gain further insight into the effect of caffeine on Ca2+ flux behavior of canine masseter muscle SR vesicles, the present study focuses on the interaction of steady-state Ca2+ accumulation and passive Ca2+ permeability in the presence or absence of endogenous calmodulin (CaM), which is known to regulate Ca2+ release channel. Caffeine (1) produced ruthenium red- or endogenous CaM-inhibitable reduction of oxalate-supported Ca2+ uptake velocity with no effect on Ca2+, Mg(2+)-ATPase activity; (2) reduced steady-state Ca2+ uptake; and (3) had no effect on the permeability of the SR vesicles to Ca2+, determined by measuring net efflux of Ca2+ after stopping pump mediated fluxes, suggesting that passive Ca2+ permeability is unimportant pathway for changing steady-state Ca2+ accumulation. The inhibitory effect of caffeine on steady-state Ca2+ uptake was moderately abolished by the removal of endogenous CaM from SR vesicles. Inositol 1,4,5-trisphosphate (IP3) caused the same effect as that of caffeine on oxalate-supported Ca2+ uptake velocity, steady-state Ca2+ uptake and passive Ca2+ permeability. In summary, the data reveal that caffeine (1) inhibits oxalate entry pathway via inhibition of CaM, and (2) directly modifies CaM-dependent component of Ca2+ fluxes in the SR and reduces steady-state Ca2+ accumulation due to increased Ca2+ release through a Ca2+ efflux pathway which is inhibited by CaM but not due to reduced catalytic activity of the pump; and that the masseter muscle SR vesicles include IP3-sensitive Ca2+ release channel.

In this study, the changes of canine pulpal vascular architecture, at various stage of growth when subjected so acute and chronic inflammation were examined through a scanning electron microscope using vascular corrosive resin casts. The following results were obtained. 1. The sites of leakage of MMA resin out of the blood vessels coincided with the site where microleakage occurred, thus suggesting that resin cast method is a useful technique to study the area where vascular permeability was increased. 2. In an acute inflammation, leakage of resin out of blood vessels was mainly observed at the sites of venular network (VN) and venous capillaries, and these could be discriminated by use of the casts method. This is in accordance with the result by Tsuchiya, Magino and Palade, where they showed that vascular permeability was preferentially observed in venule and venous capillaries. 3. In pulp with a lesser number of venules during the stage of late maturation, leakage of resin was observed from those surviving venules to the bundle of main blood vessels. 4. Leakage of resin was not observed in the terminal capillary network (TCN), but in the capillary network (CN) and VN, especially just beneath the dentin, where cavity preparation with a water spray was performed. Accordingly, the generation of heat during cavity preparation was thought to be the main reason for disturbance of the pulp. 5. Severe case of suppurative and chronic ulcerative pulpitis were generated within one week after cavity preparation. The vascular architecture was characterized by a dense granular capillary network facing the ulcerative surface. 6. One week after pulpal exposure, at the stage of early maturation of pulp, the granulated blood vessels located within the exposed pulp had a tendency to shift to a pulp polyp. And the granulated blood vessels after two months showed a pulp polyp. 7. At the late maturation stage of pulp, development the pulp chamber and dentin tubules were saturated by resin cast method, suggesting the possibility of leakage out of blood vessels and the death of some odontoblasts. The pulp at this stage shifted to a gangrous pulp. 8. In conclusion, the pulpal vascularity constantly undergoes morphologic changes incidential to various condition such as growth, maturation and inflammation. Basically, vascularity of dental pulp consists of three major layers, that is TCN, CN and VN. When it comes to the maturation stage, owing to the apposition of secondary dentin, the pulp cavity will become narrow and the vasculation within it will undergo a histologic change. As a result, most of the VN disappears.(ABSTRACT TRUNCATED AT 400 WORDS)