Coronal dentinal nodules induced by single or multiple injections of HEBP in young rats.
In the developing tooth, the bisphosphonate HEBP causes hypoplasias and hypomineralization of the enamel and dentine as well as inhibition of acellular cementum formation. Here, we describe a novel effect, associated with dentine mineralization. HEBP was administrated to young rats, and the maxillary molars were analyzed histologically. Localized dentinal nodules, protruding towards the pulp, were found in the developing crown of the molars. They occurred in regions, where the mantle dentine was about to mineralize at the time of the injection, and were more frequent at the mesial cusp side. The nodules accumulated mineral, as evidenced by the fluorescence after calcein and tetracyclin labelling. Histologically, the nodules were separated from the enamel by a layer of mantle dentine and were progressively surrounded by predentine and dentine. The nodules were interpreted to contain transport or metabolism intermediates, which were locally accumulated due to the interruption of the mineralization process by HEBP.
Brandsten
C
C
Center for Oral Biology, Karolinska Institute, Sweden.
Alatli
I
I
Wurtz
T
T
Hammarström
L
L
D000818:Animals; D003739:Dental Cementum / Q000187:drug effects; D003743:Dental Enamel / Q000187:drug effects; D003744:Dental Enamel Hypoplasia / Q000139:chemically induced; D003804:Dentin / Q000737:chemistry / Q000187:drug effects* / Q000473:pathology; D003810:Dentinogenesis / Q000187:drug effects; D012968:Etidronic Acid / Q000008:administration & dosage / Q000009:adverse effects*; D005452:Fluoresceins; D007202:Indicators and Reagents; D007279:Injections, Subcutaneous; D008855:Microscopy, Electron, Scanning; D008903:Minerals / Q000032:analysis; D008963:Molar; D051381:Rats; D017207:Rats, Sprague-Dawley; D013752:Tetracycline; D014074:Tooth Calcification / Q000187:drug effects; D014076:Tooth Diseases / Q000139:chemically induced / Q000378:metabolism / Q000473:pathology
D005452:Fluoresceins; D007202:Indicators and Reagents; D008903:Minerals; D013752:Tetracycline; D012968:Etidronic Acid; C007740:fluorexon