title: Light and transmission electron microscopy of the effects of calcium, magnesium and phosphate on dentine and enamel formed by rat molars in vitro.
abstract: The effect of addition of eight different combinations of Ca, Mg and P supplements (control, Ca, Mg, P, CaMg, CaP, PMg and CaMgP) on three-day-old rat maxillary second molars, explanted at the premineralizing stage and cultured for two weeks, was studied. Light-microscopy sections, cut parallel to the occlusal plane, were divided into four sectors and given a score according to an ordinal scale for dentine and enamel depending on the regularity of these matrices. An analysis of variance on these scores revealed a significant favourable effect of Mg, CaMg and CaMgP and an adverse effect of Ca on enamel. A favourable effect on dentine regularity was obtained after addition of Ca or Mg. Ultrastructurally, enamel changes such as amorphous enamel matrix, voids and disturbance in rod-interrod pattern were seen after addition of Ca, P, CaP. Thin enamel with less tight packing of crystals was observed after CaMg addition. A thick layer of enamel with highly-organized rod-interrod pattern was seen with Mg, PMg and CaMgP addition. It is suggested that Mg plays an important role in the interaction with Ca and P for the harmonious development of enamel and dentine in vitro.
mesh_terms: D000818:Animals; D002118:Calcium / Q000378:metabolism*; D003743:Dental Enamel / Q000378:metabolism* / Q000648:ultrastructure; D003804:Dentin / Q000378:metabolism* / Q000648:ultrastructure; D004347:Drug Interactions; D066298:In Vitro Techniques; D008274:Magnesium / Q000378:metabolism*; D008854:Microscopy, Electron; D008963:Molar; D010758:Phosphorus / Q000378:metabolism*; D051381:Rats; D014074:Tooth Calcification
chemical_list: D010758:Phosphorus; D008274:Magnesium; D002118:Calcium