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Volume 41 (1991)
- Issue 5 Pages 596-
- Issue 3 Pages 242-
- Issue 2 Pages 152-
- Issue 1 Pages 2-
Volume 41, Issue 3
Displaying 1-17 of 17 articles from this issue
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Tooth Caries of Deciduous TeethReiko IWATSUBO, Keizo SUZUKI, Hideaki IMANISHI1991 Volume 41 Issue 3 Pages 242-250
Published: July 30, 1991
Released on J-STAGE: October 27, 2010
JOURNAL FREE ACCESSWe made an oral survey of the Tibetans in three quite different areas and got interesting results. The comparative study was made in Karakoram (1974), North-west Nepal (1983), and Yunnan province, China (1989).
1) In Karakoram, North-west Nepal, the number of cases of decidous tooth caries was extremely small. On the other hand, it was very great in Yunnan province.
2) The eruption age of permanent teeth was quite similar in the three Tibetan areas. Japanese teeth change from deciduous teeth to permanent teeth at a younger age.
3) In Yunnan province, the inhabitants had many decayed teeth in the upper front jaw, and few at lower front jaw. The number of decayed deciduous molars was large as in the Japanese.
4) Caries surfaces: In Yunnan province, the number of cases of proximal and distal surface caries was great compared with that on occlusal and labiolingual surfaces. Caries in Yunnan province may be closely related to the manner of carbohydrate intake.View full abstractDownload PDF (1076K) -
Yuuki OZAWA, Yoshihiro SHIMADA1991 Volume 41 Issue 3 Pages 251-257
Published: July 30, 1991
Released on J-STAGE: October 27, 2010
JOURNAL FREE ACCESSIn order to clarify the mechanism of traumatic tooth breakdown caused by probing into carious pits and fissures, a study was carried out on artificial carious fissures made from two pieces of bovine enamel. Twenty of the artificial fissures were divided into two groups, 15 experimental and 5 control ones. A bacterial mass cultured from human dental plaque was transferred into the experimental fissure and was incubated in MSB broth for 4 weeks at 37°C. Both experimental and control fissures were probed with a dental explorer at about 800g pressure and the adhesive force required to pull the explorer was measured with an electric weighing system which was described in our previous paper. Then vertical ground sections through the fissures were prepared and observed by light and polarizing microscopy and by microradiography. Four of the twenty fissures, 3 experimental fissures and one control fissure, were examined by scanning electron microscopy (SEM). The following results were obtained. 1) There was significant difference between mean adhesive forces in experimental fissures (50.7g) and in control fissures (7.8g). 2) Tooth breakdown was recognized in both experimental and control fissures. 3) There was histopathological caries with subsurface demineralization in all experimental fissures, but not in control fissures. 4) The subsurface demineralization was wide at the entrance of the experimental fissures and became narrow toward the bottom. 5) In the SEM study, there were no prominent features in the surface enamel of experimental fissures, but eroded enamel rods were observed in the subsurface demineralization.View full abstractDownload PDF (5748K) -
Tomohisa YAMAMOTO1991 Volume 41 Issue 3 Pages 258-273
Published: July 30, 1991
Released on J-STAGE: October 27, 2010
JOURNAL FREE ACCESSIn order to study the interaction between the human body and synthesized hydroxyapatite (HAP), human peripheral monocytes (immunocytes derived from fresh venous samples) were cultured in medium containing various concentrations of HAP. Viability, phagocytosis rate, protein synthesis, DNA synthesis, enzyme activity [lactic dehydrogenase (LDH) and acid phosphatase (AcP) ] and surface antigens [Leu-15 (CD 11), Leu-M3 (CD 14), HLA-DR, Transferrin (Trans) ] were measured in monocytes cultured with HAP. After HAP treatment for 24 hrs, the viability of the monocytes was about 95 to 97% in the 0 to 200μg/ml HAP groups. In the 1000μg/ml HAP group, it decreased to about 83%. The monocyte phagocytosis rate increased according to the dose of HAP 1 hr after the treatment of HAP. At 24 hrs after HAP treatment the phagocytosis rate increased slightly slightly in monocytes treated with 0.1μg/ml HAP although it did not change for the group treated with 100μg/ml or less HAP. The protein synthesis of monocytes increased in the 0.1 to 10μg/ml HAP groups compared to the control group, and maximum enhancement (156% of control) was found in the 0.1μg/ml HAP group. DNA synthesis was not affected by the HAP treatment. LDH activity of the monocytes was almost the same for both the control and HAP treated cells 1 hr after the addition of HAP. 24 hrs after the addition of HAP. The LDH activity of monocytes treated with HAP was 3 times higher than the control. AcP activity was not affted by HAP treatment. The occurrance of surface antigens to Leu-15, Leu-M3, HLA-DR and Trans on monocytes showed a tendency to increase due to HAP exposure. These results revealed that the cytotoxicity of HAP was very low for monocytes and that HAP was phagocytized by monocytes soon after attaching to the cells. It is concluded that protein synthesis, LDH activity and surface antigens of the monocytes were stimulated in conjunction with the phagocytosis of HAP.View full abstractDownload PDF (10545K) -
Tatsumi SHIBUSAWA, Hiroshi OKONOGI, Takashi TSURUMIZU, Takashi HASHIMO ...1991 Volume 41 Issue 3 Pages 274-280
Published: July 30, 1991
Released on J-STAGE: October 27, 2010
JOURNAL FREE ACCESSThe presence and some biochemical and serological characteristics of the S. mutans group, S. sanguis, and S. salivarius in the plaque of 68 small dogs indoors were examined. Supragingival plaque samples were cultured on TYC media and colonies which showed typical morphology of each streptococcal species were subcultured and partially characterized. The S. mutans group could be detected in 19 of 68 dogs, and 3 out of 19 isolates were S. cricentus, 10 out of 19 S. mutans (serotype c), 1 out of 19 S. mutans (serotype f), and 2 out of 19 S. sobrinus. However, 3 out of 19 isolates were not differentiated into any species. S. sanguis could be detected in 15, and S. salivariusin 11 of the 68 dogs.
Three small dogs (mongrels) of 50 days of age were orally inoculated with S. mutans (serotype c) strains and fed a cariogenic diet, a modified Diet 2000, for 9 months. During this period two of the three dogs developed dental caries in their second molars.View full abstractDownload PDF (2765K) -
Effect of Contact between Probe and Gingiva, and Gingival Site for the MeasurementTakashi HANIOKA, Hideki NAGATA, Yukitaka MURAKAMI, Katsuko IWAKURA, Sa ...1991 Volume 41 Issue 3 Pages 281-288
Published: July 30, 1991
Released on J-STAGE: October 27, 2010
JOURNAL FREE ACCESSThe purpose of this study was to examine the effect of contact between the probe and gingiva, and to compare the parameters between arches, regions, and surfaces in measurement of gingival microvascular function by tissue reflectance spectrophotometry (TRS). The index of hemoglobin concentration (Hb index) and the index of oxygen saturation (SO2 index) in papillary gingiva were assessed with TRS in a standardized manner. Gingival spectra were measured immediately before and during contact between the optical probe and gingival tissue. The Hb index showed a maximum value during the procedure when the probe was in the first contact with gingiva. The SO2 index showed lower values before the contact and higher values after the first contact. When the probe/gingiva surface angle increased, the Hb index decreased but the SO2 index showed little change. These results indicate that good reliability of the measurement could be obtained by selection of a representative spectrum showing the maximum Hb index among several spectra measured at the same site. Reflectance spectra were also measured at various locations of the upper and lower arches in subjects with clinically healthy gingiva. Coefficients of variation of both indices in lingual/palatal surfaces and in molar teeth were higher than those in facial surfaces and incisor teeth, respectively. Analysis of variances indicated significant differences in both indices between facial and lingual/palatal surfaces and among the teeth but no difference between the sides and between the arches. Significant interactions were observed in both indices between arch and surface, and in Hb index between arch and tooth. Thus, the application of TRS measurements in periodontal practice should consider differences in TRS parameters at a given location in the mouth.View full abstractDownload PDF (1223K) -
Masaki IWAKURA, Yoshiro SHIBUYA, Yoko YASUNO, Yoshihiro SHIMADA1991 Volume 41 Issue 3 Pages 289-293
Published: July 30, 1991
Released on J-STAGE: October 27, 2010
JOURNAL FREE ACCESSVisual inspection for gingival hyperplasia was done and a drug questionnaire was given to 747 adults (male 317, female 430, 54.39 years old in mean) who received a health examination in a rural area of Miyagi prefecture. Characteristic gingival hyperplasia with four features (unevenness, multiplicity, demarcation and imposibility of explanation by local factors only) which we had detected at nifedipine medicated subjects was also examined. Persons receiving medication for hypertension or cardiopathy were classified as the medicated group and others as the nonmedicated group. Prevalence of gingival hyperplasia was 15.27% and 10.42%, respectively, but no statistical difference was found between the two groups (Table 3). The characteristic gingival hyperplasia was detected in twelve persons (5.91%) of 203 in the medicated group and in one person (0.19%) of 518 in the nonmedicated group, with high statistical difference (p<0.01).
This prevalence (5.91%) is about half the value which we reported for characteristic gingival hyperplasia (10.9%) in private hospital patients receiving nifedipine for hypertension or cardiopathy. Considering the fact that about half of the hypertension or cardiopathy patients in this hospital were treated with nifedipine (53.8%), prevalence value of the present study (5.91%) is not contradictory.View full abstractDownload PDF (793K) -
Daisuke INABA, Youichi IIJIMA, Okiuji TAKAGI1991 Volume 41 Issue 3 Pages 294-300
Published: July 30, 1991
Released on J-STAGE: October 27, 2010
JOURNAL FREE ACCESSAn in vitro pH-cycling experiment was performed to evaluate the changes in the mineral content in remineralized enamel and root surfaces. Tooth slabs were cut from intact human enamel and root tissue with cementum and were subjected to alternating demineralization (Dem) and remineralization (Rem) as follows: (1) enamel: A single cycle of 24-hr Dem (pH 4.0, 37°C) -10-day Rem (pH 7.0, 37°C) -24-hr Dem; (2) root: Four cycles of 2-hr Dem (pH 6.0, 20°C) -46-hr Rem (pH 7.0, 37°C) plus 2 cycles of 12-hr Dem (pH 5.0, 37°C) -36-hr Rem (pH 7.0, 37°C). Between the Dem and Rem cycles, both enamel and root slabs were immersed in 250ppm F solution for 1min. The slabs were sectioned at approximately 100μm and microradiographed. The mineral content in the tooth surfaces was assessed by digital image processing.
The results were as follows:
(1) The typical lamination resulting from pH-cycling was observed both in enamel and root surfaces.
(2) The mineral distribution was different between enamel and root surfaces, e. g., the width of the second Dem layer of enamel was much narrower than that of the first Dem layer, whereas both of the Dem layers in root surfaces showed similar width.
(3) The mineral volume of the middle part of the Dem layer was lower than that of the edge, but this mineral distribution was reversed in the Rem layer, and each layer showed a “sandwich” structure.
(4) Digital image processing of microradiographs was useful for evaluating the mineral volume in the remineralized tooth samples. Particularly the use of a pseudo-color display for monochrome images was useful for evaluating mineral distribution visually.View full abstractDownload PDF (4768K) -
Hiroshi TERAI, Daisuke HINODE, Tomie MAN-YOSHI, Atsushi NAGATA, Makoto ...1991 Volume 41 Issue 3 Pages 301-306
Published: July 30, 1991
Released on J-STAGE: October 27, 2010
JOURNAL FREE ACCESSTrypsin-like enzyme activity was measured using a synthetic fluorescent substrate, N-α-benzoyl-L-arginine-7-amido-4-methylcoumarin, in gingival crevicular fluid (GCF) collected from periodontal pockets in 14 adult periodontitis patients. Two kinds of GCF were collected from each patient using Periopapers®; one from the deepest pocket (≥4mm) and the other from the shallowest one (≤3mm). The enzyme activity was detected in all of the GCF samples, and log 10 (trypsin-like activity) was significantly correlated with probing depth (r=0.52, p<0.01).
The presence and amount of free amino acids in GCF and whole saliva was also measured by automatic amino acid analyser in another 12 patients with adult periodontitis. The amino acid amounts varied considerably in all the fluids. The free amino acid levels in whole saliva did not seem to reflect those of GCF. Because of the wide range of the concentrations of amino acids, no significant differences were found statistically in the free amino acid levels between GCF from the deepest periodontal pockets and GCF from the shallowest ones.View full abstractDownload PDF (744K) -
Toshihide KIMURA, Etsuo KISHIMOTO, Manabu MORITA, Akira ISHIKAWA, Tsuy ...1991 Volume 41 Issue 3 Pages 307-313
Published: July 30, 1991
Released on J-STAGE: October 27, 2010
JOURNAL FREE ACCESSThis study was designed to evaluate the effect of toothbrushing instruction on the periodontal health in a community. The area is 30.5km2 and has a population of 14, 000.
Ninety-five inhabitants (mean age: 47.6±9.0) participated in this study. Oral examinations were made regarding gingival inflammatory indices, tooth mobility, Oral Hygiene Index, and CPITN scores at baseline, after 1 and 2 months, and 1 year. Each time, the subjects were instructed in the toothpick method of toothbrushing intraorally. They were required to fill out questionnaires to evaluate the oral health behavior and improvement of the subjective symptoms at the final visit.
Significant improvement in the CPITN code was observed during a year. Gingival inflammatory indices improved at 1 and 2 months, but slight relapse of gingival conditions were observed in some subjects. Comparison between the relapsed group and the continuously improving group for a year, revealed that the relapsed group had a significantly lower prevalence of gingival inflammation at baseline.
The questionnaire showed the subjects' great satisfaction with the toothbrushing instruction. About 90% of them indicated positive improvement of dental health behavior. Forty percent of the participants reported improvement of bleeding gums and 18% improvement of bad breath.
These results suggested that this dental health education program was effective in the community and that inhabitants affected by periodontal disease were more easily motivated than others.View full abstractDownload PDF (930K) -
Tadashi YOSHIKAWA1991 Volume 41 Issue 3 Pages 314-318
Published: July 30, 1991
Released on J-STAGE: October 27, 2010
JOURNAL FREE ACCESSThe purpose of this study was to examine the influence of laser irradiation on remineralization of demineralized enamel. Twenty human premolar enamel slabs (3×5mm) were prepared for this study. The enamel slabs were ground down to about 400μm and immersed in 0.1M lactic acid buffer (3.0mM Ca, 1.8mM P, 1.0% carboxymethylcellulose, pH 4.5, 37°C) for 12 hours. Demineralized enamel slabs were irradiated with a Q-switch Nd-YAG laser at 50 J/cm2of total energy density. After laser irradiation, slabs were immersed in remineralizing solution (3.0mM Ca, 1.8mM P 1.0% carboxymethylcellose, 150mM NaCl, 3.0ppm F, pH 7.0, 37°C) for 10 days. The degree of remineralization was evaluated by microradiograph using calculated mineral content. Sectioned enamel slabs were also immersed in 0.5M HClO4solution for 1 minute to examine acid resistance of the remineralized enamel.
There were signs of remineralization in both the lased and unlased areas, and no clearly difference was recognized between these areas. It appears that remineralization of enamel was not inhibited by laser irradiation. The acid resistance of the remineralized enamel was higher in the lased area than in the unlased area. However, the degree of remineralization corresponding to the mineral level was not significantly different between two areas. It is probable that the permeability of enamel was not decreased by laser irradiation.View full abstractDownload PDF (2665K) -
Hiroko MIURA, Katsuhiro HARAGUCHI, Koichi MATSUDA, Emiko ISOGAI, Kimih ...1991 Volume 41 Issue 3 Pages 319-322
Published: July 30, 1991
Released on J-STAGE: October 27, 2010
JOURNAL FREE ACCESSThe monthly changes in the counts of anaerobic bacteria, streptococci, and mutans streptococci in plaque of caries-susceptible rats (SDC) and control rats (CSC) were examined at 1, 2, 3, and 4 months. Carious lesions were also evaluated at each change by Keyes' method.
No changes in the bacterial counts were observed but there was a transient increase at 3 months, especially in mutans streptococci counts. Also, no significant difference in bacterial counts was found between SDC and CSC rats. However, SDC rats had significantly higher caries scores than CSC rats after 3 months (p<0.01). The monthly age of SDC rats when their caries scores were increased was consistent with the age when their bacterial counts were significantly increased.
These results suggested that the number of mutans streptococci contributed to dental caries in SDC rats, but that it was only a necessary conditions, but not a sufficient condition, for the occurrence of caries.View full abstractDownload PDF (540K) -
Minoru YAGI1991 Volume 41 Issue 3 Pages 323-343
Published: July 30, 1991
Released on J-STAGE: October 27, 2010
JOURNAL FREE ACCESSThis study deals with the prevalence of dental caries of permanent teeth and dental fluorosis among 5 th and 6th grade Japanese schoolchildren (aged 10-12), residing in 7 different communities in the Tohoku, Kanto, and Ko-Shin-Etsu districts, in relation to the differing concentrations ranging from 0.0 to 1.4ppm of fluoride in the communities' drinking water supplies.
Information on dental health in school was obtained from school teachers, and data on dental habits at home were collected by a questionnaire filled out by parents.
In 1987, children were examined for dental caries by three dentists, adopting the ‘Blind Recording Method’ where the dentists had no information about the communities, such as the fluoride concentration in the drinking water, and for dental fluorosis by means of Dean's index by two dentists.
1, 060 children, who were continuous residents in their communities since birth, were selected for analysis. Comparing the prevalence of dental caries at a fluoride concentration of below 0.2ppm with that of above 1.0ppm, the maximum reduction rate was 69.6% in mean DMFS for 6th grade school-children.
From Quantification theory (I), the highest factor was ‘fluoride concentration in the drinking water’, associated with the prevalence of dental caries of permanent teeth. The partial correlation coefficient of ‘fluoride concentration in the drinking water’ was -0.269. A secondary factor was ‘community’, and the other factors were very low. Thus, it became clear that there is an inverse relationship between the prevalence of dental caries and the fluoride concentration in the drinking water.
In this study the optimal fluoride concentration in the drinking water that most effectively prevents dental caries in permanent teeth was 1.1 ppm.
There was no public health problem regarding dental fluorosis, for CFI was under 0.30 at concentrations of 0.0 to 1.4ppm of fluoride in the drinking water.View full abstractDownload PDF (2797K) -
Daisuke INABA, Tsuyoshi KATAYAMA1991 Volume 41 Issue 3 Pages 344-346
Published: July 30, 1991
Released on J-STAGE: October 27, 2010
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Nobuhiro HANADA, Takahide UCHIYAMA, Yoshito HAGA, Izuru OGATA, Yutaka ...1991 Volume 41 Issue 3 Pages 347-349
Published: July 30, 1991
Released on J-STAGE: October 27, 2010
JOURNAL FREE ACCESSDownload PDF (427K) -
Tamie OHASHI, Tokuko KANI, Mizuo KANI1991 Volume 41 Issue 3 Pages 350-352
Published: July 30, 1991
Released on J-STAGE: October 27, 2010
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1991 Volume 41 Issue 3 Pages 365a
Published: 1991
Released on J-STAGE: October 27, 2010
JOURNAL FREE ACCESSDownload PDF (112K) -
1991 Volume 41 Issue 3 Pages 365b
Published: 1991
Released on J-STAGE: October 27, 2010
JOURNAL FREE ACCESSDownload PDF (112K)
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