|Budget Amount *help
¥2,500,000 (Direct Cost : ¥2,500,000)
Fiscal Year 1998 : ¥900,000 (Direct Cost : ¥900,000)
Fiscal Year 1997 : ¥1,600,000 (Direct Cost : ¥1,600,000)
The aim of this study was to clarify the mineral (Ca and P) distributions and their promotion of fluoride retention in the plaque in vivo exposed to a mineral enriching mouthrinse and then to estimate factors, which have an influence on the promotion of fluoride retention in the plaque. 11 subjects consenting (20-31 years), had sampling devices containing plaque receptacles (2mm in diameter) to buccal surfaces of upper molars. After plaque had formed over 3 days, subjects were instructed to rinse with one of five rinsing solutions three times a day on 4 consecutive days. Each solution was made by excluding some ingredients out of a mineral enriching mouthrinse (urea 500mM, CaCl_2 20mM, Na_2HPO_4 12mM, Na_2PO_3F(MFP) 5mM, pH_5). Plaque collections were repeated at intervals using different solutions. Plaque samples exposed to a placebo solution with no ingredients served as control. 24 hours after the last rinsing, the sample was freeze-dried and then embedded in a methacrylate mixture.
A series of plaque sections parallel with the tooth surface (4 at 6mum then 2 at 3mum) were repeatedly cut from the outer plaque surface towards the enamel, using an ultramicrotome. The thinner sections were used for area measurement to evaluate sample volume. The thicker sections were collected into several congruous specimens. Fluorides and mineral distributions in plaque were analyzed by a method reported by Kato et al. Archs oral Biol. 42 : 521-525, 1997. Fluoride retention increased except in the deeper plaque layers. Fluoride concentrations (0.5-3.6nmol/mm^3) significantly rose in the samples exposed to solutions containing both MEP and minerals, this tendency being greater in the full mouthrinse. Both calcium and phosphorus levels significantly increased only in the plaque exposed to the mineral enriching mouthrinse. However, ANOVA indicated a difference between subjects would be a stronger factor than the type of mouthrinse for fluoride retention in plaque.
2. 次に、この予備的検討の結果を参考に、A、B両液に加え、C液:AからMFPを除外した溶液、D液:AからMFP以外を除外した溶液、E液:蒸留水(対照)の5種類の洗口液を調整した。informed consentの得られた被験者11名(年齢20〜31歳)を対象に、同様の方法で分析を行い、歯垢のフッ素保持能におよぼす要因の推定とともに予防歯科領域で利用可能な歯垢のフッ素保持能を高める手法を検討した。
4. 今後は、エナメル質表層も含めたフッ素とミネラルの動態を検討していく予定である Less