Kokubyo Gakkai zasshi. The Journal of the Stomatological Society, Japan最新文献

The mechanical characteristics of zirconia, hybrid hard resin and dental metal for crowns and fixed partial dentures (FPD) have been researched for clinical applications. However, for these kinds of restorations, the distribution of mechanical stress around the abutment teeth and periodontium during function has not been sufficiently assessed. The aim of this study was to clarify the influence of these materials upon abutment teeth and periodontium through a two-dimensional photoelastic method. Two-dimensional simulation models of three-unit FPDs were constructed from these materials. By applying a force of 400 N vertically to these FPDs, the stress distribution around the abutment teeth and alveolar bone was analyzed and the fringe orders were recorded with a transmission polariscope. As a result, the fringe order values at the root dentin around the marginal area of the pontic joint were the highest in zirconia, and the smallest in hybrid hard resin. The spread of internal stress around the marginal area was larger in the hybrid hard resin model and dental metal model than in the zirconia model. This study suggested that differences in stress distribution within the abutment teeth and around the alveolar bone were related to differences in elastic coefficients of the materials used in FPDs.

While oral care is known to play an important role in the prevention of aspiration pneumonia, its influence on immune function is unclear. In this study, we performed oral care on ten dependent elderly individuals and examined its influence on NK cell activity. The study duration was 12 weeks. During the first six weeks, the subjects cleaned their mouths as usual (control period). In the last six weeks, a dental hygienist performed oral care and denture cleaning three times a week (intervention period). The outcome measure was the quantity of oral bacteria and the detection rate of the microbe in connection with an opportunistic infection and NK cell activity before and after the intervention. Samples were collected at three time points: the beginning of the study, after the control period and before the intervention period (i. e., after six weeks), and after the intervention period (i. e., after 12 weeks). There was no significant difference in the number of oral bacteria between the control period and the intervention period. In contrast, while NK cell activity did not change during the control period, activity increased during the intervention period (p = 0.03). This finding suggests that rather than decreasing the number of oral bacteria, oral care increases NK cell activity.

Overexpression of epidermal growth factor receptor (EGFR) is known to be associated with poor prognosis in malignant tumors. Sodium-glucose co-transporter 1 (SGLT1) is a membrane protein that transports glucose across cellular membranes. Recently, EGFR has been shown to stabilize SGLT1 and promote glucose uptake into cancer cells. The purpose of this study was to investigate the coexpression of EGFR and SGLT1 and their relationships with clinicopathological features in oral squamous cell carcinoma (OSCC). Total cell lysates from OSCC cell lines were prepared to check the protein expression of EGFR and SGLT1 by western blotting assay. Both proteins can be detected and the expression levels of SGLT1 were significantly correlated with those of EGFR. Pearson's product-moment correlation coefficient was 0.89 (p = 0.016). Transient overexpression of EGFR in HeLa cells showed that SGLT1 expression was increased by EGFR, suggesting that EGFR can stabilize the protein stability of SGLT1. To see whether mRNA expression of SGLT1 is correlated with protein expression, real-time PCR was performed. The results revealed no compatible expression between mRNA and protein, indicating that this discrepancy is caused by the post-transcriptional modification. Immunohistochemical staining using surgical specimens from 52 tongue SCC patients also showed a significant correlation between EGFR and SGLT1 expression. Moreover, EGFR/SGLT1 expression was inversely correlated with tumor differentiation (p = 0.004). These results indicate that EGFR/SGLT1 coexpression may contribute to the growth and survival of OSCC, but further study is needed to clarify the implication of these proteins in the manifestation of malignancy and clinical significance.

Purpose: The purpose of this study was to clarify the clinico-pathological findings of Warthin's tumors.

Subjects and methods: Twenty cases of Warthin's tumors treated at our clinic during the past 22 years and their medical charts and imaging films were reviewed.

Results: Warthin's tumors occurred more frequently in middle-aged or elderly men than in women. Solitary tumors were significantly larger (p < 0.05) than multiple tumors. Warthin's tumors that accumulated 99mTc were significantly larger (p < 0.05) than those that did not. In addition, there was no difference in clinical findings between the two histopathologic types of Warthin's tumors.

Conclusion: The frequent occurrence of multiple Warthin's tumors indicated the importance of an accurate clinical and radiological examination of parotid glands, in order to detect possible multiple lesions prior to treatment.

To improve and maintain medical safety and quality, it is necessary to construct and manage a safe and economical medical system. Almost five years have passed since single-pack dental hygienic materials were introduced into daily clinical practice in the University Hospital, Faculty of Dentistry, Tokyo Medical and Dental University. The costs of purchasing hygienic materials themselves are higher when using outsourced sterilized single packed ones, compared with when using intra-murally sterilized ones in the past. Proper usage of single-pack hygienic materials sterilized with Ethylene Oxide Gas (EOG) would reduce waste of unused materials and save labor for staff in the Section of Central Supplies. Financially, the use of hygienic materials could be reduced if single-pack dental hygienic materials by outsourcing were introduced into the hospital, because all costs for sterilizing hygienic materials in the hospital could be eliminated.

For a better understanding of the structures comprising the human body and in view of the possible need for future revision of anatomical nomenclature, Latin anatomical names of skeletal canals (including canaliculi) in Terminologia Anatomica were analyzed and classified, and compared with the corresponding Japanese anatomical names. The words following Canalis or Canales indicated: (1) the structure to which the canal belongs, (2) the structure to which the opening of the canal belongs, (3) the position of the canal, (4) the structure to which the canal leads, (5) the structure that exists near the opening of the canal, (6) the structure that transmits the canal, (7) the structure that is a component of the canal, or (8) the function of the canal. The analysis of Latin names and comparison with Japanese names clarified some characteristics of both names and revealed some problems in them.

The association between phenytoin-induced gingival hyperplasia (PIGH) and five major periodontopathic bacteria was investigated by real-time PCR in 12 subjects (30.6 +/- 7.95 years of age) with severe motor and intellectual disabilities. The subjects had not received antibiotics or periodontal therapy within three months. A healthy gingival site or a site with the lowest gingival hyperplasia score (minimum site), and a site with the maximum score of gingival hyperplasia (maximum site) on each subject were selected for investigation. The clinical parameters were measured after microbial sampling. The following results were obtained: 1. The detection rates of both Treponema denticola and Porphyromonas gingivalis were 75% (9/12) at the maximum sites, and that of Tannerella forsythia was 33.3% (4/12). The detection rate of Prevotella intermedia was 58.3% (7/12), but no significant correlation was observed between this bacterium and the other types of bacteria in quantitative analysis. 2. The detection rate of P. gingivalis with type II fimA was 25% (1/4) at the minimum sites, and 83.3% (5/6) at the maximum sites. 3. The samples were divided into three groups; namely, those with no detection of P. gingivalis at either the minimum sites or the maximum sites, no detection at the minimum sites but detection at the maximum sites, and detection at both sites. In conclusion, 1) the detection rates of T. denticola and P. gingivalis were the highest at the maximum sites. In particular, the detection rate of P. gingivalis with type II fimA was high in the present study, and 2) the subgingival microflora was diverse because of the diverse severity of gingival inflammation associated with PIGH.