Shoni shikagaku zasshi. The Japanese journal of pedodontics最新文献

The purpose of this study was to evaluate the erosive properties of sport drinks and to clarify the facts which effect these properties. We analysed the contents of 3 kinds of sport drinks and measured their capacity to dissolve hydroxyapatite in vitro under several duration times. The following results were obtained: 1) The pH Values of the sport drinks ranged from 2.91 to 4.07. 2) The total sugar concentration of the sport drinks ranged from 3.24 to 5.95%. The sugar were consisted mainly to sucrose, glucose and fructose, but their proportion in the sport drinks had different values respectively. 3) After stirring for 1 and 5 minutes, there was a negative correlation (Spearmann's rank correlation coefficient test) between the pH values of the sport drinks and the amounts of Ca2+ released into them. And after stirring for 10 and 20 minutes, there was a negative correlation between the Ca concentrations of the sport drinks and the amounts of Ca2+ released into them. 4) The addition of sugar to the sport drinks showed no effect on their capacity to dissolve hydroxyapatite. The results suggested that tooth erosion depends on the pH value of the sport drink at the early stage when the tooth contacted it, and also tooth erosion depends on the Ca concentration of the sport drink when the tooth is in contact with it for a long time.

We prepared new root canal cements for trial. These cements were comprized of calcium aluminate and calcium hydroxyde for setting in a root canal and a bioabsorbable property. The biocompatibility of these cements were then evaluated with kinds of cytotoxicity tests and were compared with three kinds of root canal cements on the market such as Calvital (CV), Canals (CA) and Neodyne (ND). As a result of the millipore filter test using HeLa cells, three kinds of trial cements and CV showed moderate cytotoxicity at every stage. The toxicity of CA and ND were related to the period of administration and the two products showed severe cytotoxicity 24 hours after the administration. The cell growth inhibition test using L-929 cells revealed that the inhibition of the three kinds of trial cements was based on a strong alkalinity caused by calcium hydroxyde and the inhibition on the cell growth was related to the calcium hydroxyde content in these cements. However, the inhibition of these cements was smaller than that of CV and they showed no inhibition in the last stage of the cell culture, while CA and ND caused the mild inhibition. Therefore, we have concluded that these trial cements are useful for root canal filling because they have better affinity to the cultured cells than CV, CA and ND.

Cyclosporin-A (CsA) which is an effective immunosuppressive agent to control the rejection of organ transplants causes gingival overgrowth as one of accompanying side effects. However, the mechanism of this particular gingival overgrowth still remains unclear. This seems to be largely due to the difficulty of reproducing gingival overgrowth in experimental animals, especially in rodents. The purpose of the present study was to establish a rat model for CsA-induced gingival overgrowth. Specific pathogen-free Fischer and Sprague-Dawley rats (20 days old) were used and fed a caries inducing diet containing CsA. The degree of gingival overgrowth was measured, and histological examination of the gingival sections was performed. The results obtained were as follows; 1. Marked gingival overgrowth was noted around mandibular molars of all rats fed died 2000 containing 56% sucrose supplemented with CsA (a diet of 120-200 mg/kg). This overgrowth was more conspicuous in buccal than in lingual gingiva. However, there were no differences between the two strains of rat in the macroscopic findings as well as in the severity of CsA-induced gingival overgrowth. 2. Rats receiving CsA treatment for 40 days (at 63 days of age) showed the maximum level of gingival overgrowth in both strains of rats. When the gingival sulcus depths at 48 days of age were compared, the S.D. rats seemed to be a higher responder to CsA than the Fischer rats. 3. CsA treated rats showed significantly higher plaque scores than untreated rats. However, CsA-induced gingival overgrowth was little affected by this enhancement of plaque accumulation in the rats infected with S. sobrinus.(ABSTRACT TRUNCATED AT 250 WORDS)

A 4-year-old boy was examined with a chief complaint of "Delayed eruption of maxillary right deciduous central incisor". Oral examination revealed a firm swelling on the labial gingiva at the right deciduous incisor of maxilla. Radiographic examination revealed that odontoma-like substances disturbed the eruption of the central deciduous maxillary incisor. The odontoma-like substances were removed surgically and examined histopathologically. The thin sections showed findings typical of a Calcifying Odontogenic Cyst with Odontoma.

The caries-inducing activity of soybean-oligosaccharide (SOR: stachyose- and raffinose-rich sugar mixture) was examined in in vitro and in vivo experiments. Streptococcus mutans MT 8148R fermented SOR and produced acids. However Streptococcus sobrinus 6715 did not ferment. SOR was not able to act as a substrate for crude glucosyltransferases (GTase) of these mutans streptococci to synthesize the water-insoluble glucan. However, SOR did not inhibit the synthesis of water-insoluble glucan from sucrose by crude GTase. SOR was proved to be of low cariogenicity in rats infected with S. sobrinus 6715.

A case of a primary supernumerary tooth in a 18 month old girl was reported. 1. The supernumerary tooth was located in the maxillary incisor area. 2. The maxillary left primary central incisor and the primary supernumerary tooth were impacted. 3. The clinical and radiographic findings indicated that the primary tooth in the mesial position was the supernumerary tooth, and therefore it was removed. 4. Three days after extraction of the mesiodens, the left primary central incisor erupted. The tooth completely erupted in two months. 5. The radiographic examination showed no supernumerary succedenous teeth.

The purpose of this study was to investigate the method of diagnosis of deciduous tooth pulpitis to make sure of the extent of the inflammation for more appropriate pulp therapy. The subjects were 100 decayed deciduous teeth of the 81 normal healthy children aged from 2y9m to 11y2m, which justified the vital pulp amputation therapy according to Nagasaka's deciduous tooth pulpitis diagnosis criteria. The blood picture was compared with the histological structure of the coronal pulp and then observed after treatment. The diagnosis of the deciduous tooth pulpitis was considered by the blood picture in the dental pulp. The results were as follows. 1. As to the blood picture in the deciduous dental pulp, it was suggested that the lymphocyte ratio was able to be taken for the discrimination of the deciduous tooth pulpitis, because ratio of lymphocyte in the coronal pulp was higher than its normal values in the peripheral blood picture regardless of the age. 2. As to the histological structure of the removed coronal pulp, the inflammatory degree was divided into 4 types; (-) no evidence of inflammation, (+) slightly confined infiltration of the inflammatory cells, (++) slightly or moderately diffused infiltration, ( ) severely diffused infiltration, when the numbers of the case at each degree type were (-) 0, (+) 37, (++) 47 and ( ) 16 cases. 3. As to the ratio of the lymphocyte ratio over 60% against all at each degree type, (+) 86.5% and (++) 61.7% were much higher than ( ) 0%. 4. The ratio of cases in which it was difficult to control bleeding at ratios of the coronal pulp amputations were type (+) 32.4% and (++) 25.5% in type, however, type ( ) showed high rate (62.5%). 5. As a result of the clinical and X-ray examination after vital pulp amputation therapy, the number of poor case was 12 of 42 cases (28.6%) in type (+) (++) and 4 of 4 cases (100%) in type ( ). 6. This result suggests that the vital pulp amputation therapy is not adequate when it is hard to control bleeding and the lymphocyte ratio of blood picture in the coronal pulp shows under 57%.

We found pure primary supernumerary teeth in the maxillary right deciduous incisor region of a 3 year 11 month old girl. We reported the results of her oral and X-ray analysis results. We would like to report our findings on the results of her oral and X-ray analysis. 1) Two of the primary supernumerary teeth were found between the incisor and canine teeth in the right side of the primary dental arch, and their color, form and size were very similar to normal primary lateral incisor teeth. 2) We also found pure secondary supernumerary teeth by means of X-ray analysis. 3) We suggest that the permeability of the X-ray is important for the ascertainment of both primary and secondary supernumerary teeth by mean of X-ray analysis.

The purpose of this study was to discover the changes in the adaptation of children to the Dental setting, and to discover the relationship between the adaptation, and the personality of the child, the personality of the mother, as well as the relationship between the mother and child. The subjects were 60 two to six year old children and their mothers who visited at the Department of Pedodontics, School of Dentistry, Showa University. The results were as follows: 1) The changes of adaptation were classified in groups of four classes. Four groups: Continuous Adaptability (45.0%) Acquired Adaptability (18.3%) Continuous Inadaptability (16.7%) Extreme Inadaptability (20.0%) 2) The inadaptability groups (Continuous Inadaptability and Extreme Inadaptability) of the two to three year old children did not correlate to the change of adaptation and personality of the child, and the relationship between the mother and child. 3) The extreme inadaptability group with the four year old children showed a connection with the change of adaptation and the various Psychological Tests. Concerning personality, the children showed elements of "dependence" "retrogression" and "maladaptation to school (kindergarten)". Concerning the mother child relationship, there were elements of "anxiety" "dotage" "follow blindly" "disagreement". 4) Nobody showed extreme inadaptability in the group of five to six year old children. Continuous Inadaptability group with the five to six year old children showed scarcely any problems. 5) The Personality of mother did not correlate to the change of adaptation of children in the dental setting.

FluoroBond is one kind of fluoride releasing, visible light-activated bonding system for orthodontic bracket placement. The first aim of this study was to investigate the fluoride release from FluoroBond. The second aim of this study was to determine the fluoride uptake by human enamel which was immersed in distilled water for 30 days in contact with FluoroBond. The third aim of this study was to demonstrate the fluoride uptake by human enamel adjacent to the bracket as well as by the human enamel beneath the bracket which was placed using FluoroBond, and immersed for 30 days in distilled water. The results obtained were as follows. 1) A great amount of fluoride was released from FluoroBond immediately after immersion. The fluoride released weakend rapidly over the first 10 days. However, the fluoride released became stable after the 10th day. 2) The uptake of fluoride from FluoroBond was large both on the surface and the subsurface enamel in contact with it. 3) When FluoroBond was used as a bracket bonding material, fluoride was absorbed from FluoroBond by the enamel not only under the bracket but also adjacent to the bracket.