Remineralization of Enamel and Dentin by A Chewing Gum Containing Phosphoryl-Oligosaccharide Calcium (POs-Ca) in situ

著者らはリン酸化オリゴ糖カルシウム塩(POs-Ca)が馬鈴薯澱粉の加水分解物より抽出でき,カルシウムの溶解性を高めることを先に報告した。本研究の目的は,POs-Ca配合シュガーレスガムのエナメル質および象牙質の再石灰化におよぼす効果を口腔内実験により確認することである。12名のボランティア(男性6名,女性6名;平均22歳)をランダムに2群に分け,二重盲検,クロスオーバーデザインの口腔内実験を行った。各被験者は脱灰した牛歯エナメル質および象牙質ディスクを取り付けた上顎口蓋プレートを装着し,キシリトールガムまたは2.6%POs-Ca配合キシリトールガムのいずれかを,1日4回噛んだ(期間:2週間/ガム)。実験期間中,フッ化物は使用せず,エナメル質ディスクが乾燥しないよう注意した。エナメル質ディスクのマイクロラジオグラフから脱灰深度ldを評価した。POs-Caガム群のエナメル質および象牙質のld値は,それぞれ70±11μmならびに71±13μm(Mean±SD)で,キシリトールガムの値(エナメル質:101±21μm,象牙質:95±13μm)よりも25-31%減少していた(p<0.001)。このミネラル蓄積のメカニズムは,POs-Caが唾液のCa/P比をハイドロキシアパタイトの比率(1.67)に向けて高め,歯質に対して過飽和なミネラル状態を維持させたことによると考えられた。本研究より,2.6%POs-Ca配合シュガーレスガムを毎日利用することは,エナメル質と象牙質,双方の再石灰化を強く促進し,齲蝕予防に有効であることが示唆された。It was previously shown that phosphoryl-oligosaccharide calcium (POs-Ca) can be prepared from potato starch hydrolysates and substantially promote the solubility of calcium. The aim of this study was to investigate the effects of a sugar-free chewing gum containing POs-Ca on remineralization of enamel and dentin in situ. Twelve healthy volunteers (6 males and 6 females ; mean age=22 y old) participated in a double-blind cross-over design intraoral study. Each participant wore a removable palatal appliance containing both of demineralized enamel and dentin disks and chewed a xylitol gum or xylitol plus 2.6% POs-Ca gum 4 times a day (period : 2 w per gum). The mineral distributions of the specimens were quantified by microradiography. The lesion depth (ld) of enamel (Mean±SD=70±11 μm) and dentin (71±13 μm) in the POs-Ca group were significantly reduced by 25-31% compared with the xylitol gum (101±21 μm in enamel and 95±13 μm in dentin ; p<0.001). The proposed mechanism of mineral accumulation by POs-Ca is that they contribute to increase salivary Ca/P ratio and maintain a state of supersaturation of calcium with respect to tooth substances enhancing remineralization. In conclusion, it was suggested that daily use of a sugar-free chewing gum containing 2.6% POs-Ca enhances remineralization both in enamel and dentin lesions considerably

Effects of Phosphoryl-Oligosaccharides (POs) on Remineralization of Enamel Lesions in vitro

著者らは,馬鈴薯澱粉の加水分解物より調製されるリン酸化オリゴ糖(POs)がカルシウムの溶解を強く促進し,カルシウム-リン酸の沈殿形成を阻害することを報告した。本研究の目的はエナメル質の齲蝕様病巣の再石灰化におよぼすPOsの効果をin vitroで検討することである。ウシエナメル質試料を0.1M乳酸ゲル(pH5)で脱灰後,NaFとして2ppmFまたは様々な濃度のPOs(0.07-4%)を添加したミネラル溶液(20mM Hepes,1.5mM CaCl_2,0.9mM KH_2PO_4,pH7)に37℃で7日間,浸漬した。エナメル質のミネラル濃度分布はtransversal microradiographyにより定量化した。0.07-0.2%のPOsを含むミネラル溶液で処理した試料のミネラル喪失量(ΔZ,vol%・μm)は,脱灰エナメル質よりも有意に低く(p<0.001),しかも2ppmF群と統計学的に同等の値であった。POs群試料の再石灰化率はPOs濃度の対数値と有意な負の相関を示した(r=0.99,p<0.0001)。本研究の結果から,POsは新規かつユニークなエナメル質の再石灰化促進物質であり,栄養学的なアプローチにより齲蝕予防に活用しうる可能性が示唆された。We reported that phosphoryl-oligosaccharides (POs) prepared from potato starch hydrolysates strongly solubilize calcium and inhibit formation of calcium phosphate precipitates. The aim of this study was to examine the effects of POs on remineralization of caries-like lesions in enamel in vitro. Bovine enamel slabs were demineralized in a 0.1 M lactic acid gel (pH 5) at 37℃ for 3 w, and subsequently remineralized in a mineral solution (20 mM Hepes, 1.5 mM CaCl_2, 0.9 mM KH_2PO_4, pH 7 ) with addition of 2 ppm F^- as NaF or various concentrations of POs (0.07-4%) at 37℃ for 7 d. The mineral distributions in enamel were quantified by transversal microradiography. The mineral loss values (ΔZ, vol%・μm) in the samples treated by the mineral solution containing 0.07-0.2% POs were significantly lower (p<0.001) compared with demineralized enamel samples and were statistically similar to that in the samples in 2 ppm F group. Remineralization rates of the samples in the POs groups were inversely correlated with the logarithmic values of POs concentration with a significant correlation coefficient (r=0.99, p<0.0001). The present results suggested that POs may be a novel and unique substance to enhance enamel remineralization, and could be utilized for caries prevention by nutritional approach

Relationship between oral status and prevalence of periodontopathic bacteria on tongues of elderly individuals.

Colonization of periodontopathic bacteria is associated with increased risk for systemic diseases. However, few studies have investigated the relationships between oral status factors as well as health related-quality of life (HR-QOL) and the prevalence of such bacteria in elderly individuals. This study investigated the prevalence of Porphyromonas gingivalis, Prevotella intermedia, Treponema denticola, and Tannerella forsythia in 165 community-dwelling functionally independent 85-year-old Japanese individuals (93 dentate, 72 edentulous) and the relationship to oral status, including oral malodor and HR-QOL. All 4 of the studied periodontopathic bacteria were found more frequently in tongue coating samples from dentate than edentulous subjects, and the prevalence of P. gingivalis, P. intermedia, and T. denticola was significantly related to the number of teeth with a periodontal pocket depth (>/= 4 mm). These results suggest the existence of a stable circulation of periodontopathic bacteria between the gingival sulcus and tongue coating over time with teeth. In addition, the presence of teeth with a deep pocket and colonization of T. denticola were positively related to the level of CH(3)SH, while the number of present teeth positively contributed to HR-QOL, especially in regard to mental health. In conclusion, since dentate state can retain colonization of periodontopathic pathogens in the oral cavity, both periodontal treatment and tongue care are important for maintaining a healthy oral status in the elderly, and possibly results in avoidance of a risk for tooth loss and decline in HL-QOL, as well as protects from systemic diseases

DENTAL SURVEY IN NIGERIA PART: 4. PREVALENCE AND SEVERITY OF PERIODONTAL DISEASES

Six hundred and seventy-three school children from the age of 3 to 20 living in the urban and the rural areas of Nigeria were examined by the Joint Dental Epidemiological Survey in 1986. The survey was funded by the Grant-in Aid from the Japanese Ministry of Education, Science and Culture, and was conducted by both the Japanese survey team and the staff from the University of Ife, Ile-Ife, Nigeria. The periodontal state of the children was evaluated according to the Community Periodontal Index for Treatment Needs (CPITN) by WHO (1).The prevalence of periodontal diseases was found to be 84.2% within the sample with a high occurrence of gingivitis and heavy deposits of calculus. However, there was little evidence of damage to the periodontal tissues. This can be attributed to the nature of their diet. The results suggested that there would be an increasing need for well-planned and organized public educational programs for the Nigerian children to promote better Oral hygiene coupled with parental involvement in the prevention at home

JOINT EPIDEMIOLOGICAL LONGITUDINAL DENTAL SURVEY IN NIGERIA, ESPECIALLY IN COMPARISON WITH THAT OF JAPANESE

Since 1980 we carried out a longitudinal dental survey in Ile-Ife, as a joint study with the dental school of Ife University, Nigeria, being supported by A Grant under The Monbusho International Scientific Research Program for ten years. One thousand one hundred seventy-one children and adults were examined in the 1991 survey. The data were compared with the data in the previous survey and Japanese survey. Results were as follows: 1) Caries prevalence rate and the average number of DMFT were still very low, especially showing that both the caries prevalence and the average number of DMFT decreased in the rural areas because the attrition proceeded faster than the caries, 2) Nigerian deciduous and permanent dentition were larger than in the Japanese in all items measured , 3) the condylar head was transform ed from the round shape to the ultra-flat shape with age, 4) there was a fewer incidence of severe periodontal diseases despite of the marked deposition of calculus, 5) with respect to Nigerian foods, there was no difference between the rainy and dry seasons in both the urban and rural communities, 6) the weaning period of the baby is decided by their mother, taking care of the health of the baby, almost all babies at one year to two years and a few at three years and 7) the menu for the breakfast, lunch and supper of the baby was made considering the nutritional aspect of the baby