title: VDR deficiency affects alveolar bone and cementum apposition in mice.
abstract: OBJECTIVE
  To compare the mineralisation density (MD), morphology and histology of alveolar bone and cementum amongst VDR +/+, VDR -/-, and VDR -/- groups supplemented with a diet TD 96348, containing 20% lactose, 2.0% calcium and 1.25% phosphorous.
  
  
  METHODS
  Four groups of mice (6 mice/group) were identified by genotyping: VDR +/+ mice (VDR wild type), VDR -/- mice (VDR deficient), VDR -/- offsprings derived from VDR -/- parents receiving a supplemental diet (early rescued), and VDR -/- mice fed with a supplemental diet beginning at age one month (late rescued). All mice were sacrificed at age 70.5 days. Micro-CT was used to compare MD and morphology of alveolar bone and cementum. H-E and Toluidine blue staining was used to examine the ultrastructure of the alveolar bone and cementum at matched locations.
  
  
  RESULTS
  In VDR -/- group, alveolar bone and cementum failed to mineralise normally. Early rescue increased MD of alveolar bone in VDR -/- mice with excessive alveolar bone formation, but which not observed in late rescue group. MD and morphology of cementum-dentine complex in both early and late rescue groups were comparable with VDR +/+ group when feeding with high-calcium rescue diet.
  
  
  CONCLUSIONS
  VDR affects alveolar bone mineralisation and formation systemically and locally. However, cementum apposition and mineralisation is mainly regulated by calcium concentrations in serum.
authors.affiliation: Department of Prosthodontics, School of Dentistry, University of Alabama at Birmingham, 1530 rd Ave S, Birmingham, AL 35294-0007, United States. zhangxm@uab.edu
authors.forename: Xueming
authors.initials: X
authors.lastname: Zhang
authors.forename: Firoz
authors.initials: F
authors.lastname: Rahemtulla
authors.forename: Ping
authors.initials: P
authors.lastname: Zhang
authors.forename: Huw F
authors.initials: HF
authors.lastname: Thomas
mesh_terms: D000367:Age Factors; D000539:Alveolar Process / Q000503:physiopathology* / Q000648:ultrastructure; D000818:Animals; D015519:Bone Density / Q000502:physiology; D002113:Calcification, Physiologic / Q000502:physiology; D002136:Calcium, Dietary / Q000627:therapeutic use; D025021:Cementogenesis / Q000502:physiology*; D004396:Coloring Agents; D003739:Dental Cementum / Q000503:physiopathology / Q000648:ultrastructure; D003786:Dental Pulp Cavity / Q000473:pathology / Q000503:physiopathology; D003804:Dentin / Q000473:pathology / Q000503:physiopathology; D003810:Dentinogenesis / Q000502:physiology; D019587:Dietary Supplements; D005260:Female; D007785:Lactose / Q000627:therapeutic use; D008297:Male; D008334:Mandible / Q000473:pathology / Q000503:physiopathology; D051379:Mice; D018345:Mice, Knockout; D008963:Molar / Q000473:pathology / Q000503:physiopathology; D010012:Osteogenesis / Q000502:physiology*; D010024:Osteoporosis / Q000473:pathology / Q000503:physiopathology; D016226:Phosphorus, Dietary / Q000627:therapeutic use; D018167:Receptors, Calcitriol / Q000172:deficiency* / Q000502:physiology; D014048:Tolonium Chloride; D014074:Tooth Calcification / Q000502:physiology; D055114:X-Ray Microtomography
chemical_list: D002136:Calcium, Dietary; D004396:Coloring Agents; D016226:Phosphorus, Dietary; D018167:Receptors, Calcitriol; D014048:Tolonium Chloride; D007785:Lactose