title: Optimization of calcium concentration of saliva with phosphoryl oligosaccharides of calcium (POs-Ca) for enamel remineralization in vitro.
abstract: OBJECTIVE
  Phosphoryl oligosaccharides of calcium (POs-Ca) are highly soluble calcium source made from potato starch. The aim of this study was to investigate the optimal concentrations of POs-Ca for the remineralization of subsurface enamel lesions in vitro.
  
  
  METHODS
  Demineralized bovine enamel slabs (n=5) were remineralized in vitro for 24h at 37°C with artificial saliva (AS) containing 0-0.74% POs-Ca to adjust the Ca/P ratio to 0.4-3.0, then sectioned and analysed by transversal microradiography (TMR). The data were analysed by Scheffe's post hoc test. The Ca/P ratio with most remineralization was used to investigate the effect of calcium on enamel remineralization (n=11). The demineralized slabs were treated with AS with calcium-chloride- (CaCl2-) or POs-Ca with an identical calcium content, and sectioned for TMR and wide-angle X-ray diffraction (WAXRD) analyses to evaluate the local changes in hydroxyapatite (HAp) crystal content. The data were analysed using the Mann-Whitney U-test.
  
  
  RESULTS
  The highest mineral recovery rate resulted from addition of POs-Ca to adjust the Ca/P to 1.67. At this ratio, the mineral recovery rate for AS containing POs-Ca (24.2±7.4%) was significantly higher than that for AS containing CaCl2 (12.5±11.3%) (mean±SD, p<0.05). The recovery rate of HAp crystallites for AS containing POs-Ca (35.7±10.9%) was also significantly higher than that for AS containing CaCl2 (23.1±13.5%) (p<0.05). The restored crystallites were oriented in the same directions as in sound enamel.
  
  
  CONCLUSIONS
  POs-Ca effectively enhances enamel remineralization with ordered HAp at a Ca/P ratio of 1.67.
authors.affiliation: Institute of Health Sciences, Ezaki Glico Co., Ltd., 4-6-5 Utajima, Nishiyodogawa-ku, Osaka-shi, Osaka 555-8502, Japan.
authors.forename: Tomoko
authors.initials: T
authors.lastname: Tanaka
authors.affiliation: Institute of Health Sciences, Ezaki Glico Co., Ltd., 4-6-5 Utajima, Nishiyodogawa-ku, Osaka-shi, Osaka 555-8502, Japan. Electronic address: kobayashi-takatsugu@glico.co.jp.
authors.forename: Takatsugu
authors.initials: T
authors.lastname: Kobayashi
authors.affiliation: Institute of Health Sciences, Ezaki Glico Co., Ltd., 4-6-5 Utajima, Nishiyodogawa-ku, Osaka-shi, Osaka 555-8502, Japan.
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Takii
authors.affiliation: Institute of Health Sciences, Ezaki Glico Co., Ltd., 4-6-5 Utajima, Nishiyodogawa-ku, Osaka-shi, Osaka 555-8502, Japan.
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Kamasaka
authors.affiliation: Japan Synchrotron Radiation Research Institute, 1-1-1 Kouto, Sayo-cho, Sayo-gun, Hyogo 679-5198, Japan.
authors.forename: Noboru
authors.initials: N
authors.lastname: Ohta
authors.affiliation: Japan Synchrotron Radiation Research Institute, 1-1-1 Kouto, Sayo-cho, Sayo-gun, Hyogo 679-5198, Japan.
authors.forename: Tatsuhito
authors.initials: T
authors.lastname: Matsuo
authors.affiliation: Japan Synchrotron Radiation Research Institute, 1-1-1 Kouto, Sayo-cho, Sayo-gun, Hyogo 679-5198, Japan.
authors.forename: Naoto
authors.initials: N
authors.lastname: Yagi
authors.affiliation: Institute of Health Sciences, Ezaki Glico Co., Ltd., 4-6-5 Utajima, Nishiyodogawa-ku, Osaka-shi, Osaka 555-8502, Japan.
authors.forename: Takashi
authors.initials: T
authors.lastname: Kuriki
mesh_terms: D000818:Animals; D017610:Calcium Compounds / Q000494:pharmacology*; D002417:Cattle; D003743:Dental Enamel / Q000378:metabolism*; D017886:Durapatite / Q000378:metabolism; D066298:In Vitro Techniques; D009844:Oligosaccharides / Q000494:pharmacology*; D010755:Organophosphates / Q000494:pharmacology*; D012463:Saliva / Q000737:chemistry*; D012464:Saliva, Artificial; D014089:Tooth Remineralization / Q000379:methods*; D014961:X-Ray Diffraction
chemical_list: D017610:Calcium Compounds; D009844:Oligosaccharides; D010755:Organophosphates; D012464:Saliva, Artificial; D017886:Durapatite