title: Calcium phosphate-based solutions promote dentin tubule occlusions less susceptible to acid dissolution.
abstract: OBJECTIVE
  To determine the efficacy supersaturated calcium phosphate (CaP) solutions containing fluoride (F) and zinc (Zn) ions in occluding dentin tubules with precipitates less susceptible to acid dissolution and to compare the performance of these solutions with the oxalate solutions containing calcium (Ca) or phosphate (P) ions.
  
  
  METHODS
  Dentin sections from human molars divided into groups: Group A - control (treated with double distilled H2O), Groups A1, A2 and A3 were treated with experimental solutions supersaturated with respect to F and Zn-substituted calcium phosphates. Solutions A1 and A2 were similar in composition but differed in pH values (A1, pH 7; A2, pH 5.5). Solutions A2 and A3 were similar in pH (pH 5.5) but the A3 solution had twice the concentrations of F and Zn2+ ions compared to A2. Another group of dentin sections were treated with A3 solution, oxalate solution containing Ca (OX/Ca) and OX solution containing P (OX/P). The control and treated dentin sections were characterized using scanning electron microscopy.
  
  
  RESULTS
  All treated dentin sections showed occluded dentin tubules; with the group A3 showing the highest percent of occluded dentin tubules. The precipitates in the dentin tubules treated with A3 remained while those treated with OX/Ca or OX/P dissolved after exposure to an acidic buffer.
authors.affiliation: Department of Pediatric Dentistry, Guanghua School of Stomatology, Sun Yat-sen University, Guangzhou, China.
authors.forename: Haijing
authors.initials: H
authors.lastname: Gu
authors.forename: Junqi
authors.initials: J
authors.lastname: Ling
authors.forename: John P
authors.initials: JP
authors.lastname: LeGeros
authors.forename: Racquel Z
authors.initials: RZ
authors.lastname: LeGeros
mesh_terms: D000143:Acids; D000293:Adolescent; D000328:Adult; D001031:Apatites / Q000494:pharmacology; D002021:Buffers; D002122:Calcium Chloride / Q000494:pharmacology; D002130:Calcium Phosphates / Q000494:pharmacology*; D002327:Cariostatic Agents / Q000494:pharmacology*; D002712:Chlorides / Q000494:pharmacology; D003804:Dentin / Q000187:drug effects* / Q000648:ultrastructure; D057133:Dentin Desensitizing Agents / Q000494:pharmacology*; D003808:Dentin Solubility / Q000187:drug effects*; D006801:Humans; D006863:Hydrogen-Ion Concentration; D008422:Materials Testing; D008855:Microscopy, Electron, Scanning; D010070:Oxalates / Q000494:pharmacology; D010710:Phosphates / Q000494:pharmacology; D017680:Potassium Compounds / Q000494:pharmacology; D012969:Sodium Fluoride / Q000494:pharmacology; D012995:Solubility; D055815:Young Adult; D017967:Zinc Compounds / Q000494:pharmacology
chemical_list: D000143:Acids; D001031:Apatites; D002021:Buffers; D002130:Calcium Phosphates; D002327:Cariostatic Agents; D002712:Chlorides; D057133:Dentin Desensitizing Agents; D010070:Oxalates; D010710:Phosphates; D017680:Potassium Compounds; D017967:Zinc Compounds; C016837:zinc chloride; D012969:Sodium Fluoride; C020243:calcium phosphate; C013216:potassium phosphate; D002122:Calcium Chloride