Journal of Dental Research, Vol 69, 1195-1204, Copyright © 1990 by International & American Associations for Dental Research Online Journals
Histopathology of root surface caries
P. Schupbach, B. Guggenheim and F. Lutz
Department of Oral Microbiology and General Immunology, University of Zurich, Switzerland.
The histopathology of active and arrested human root caries was examined in
extracted teeth by different optical methods. Significant differences were
observed between the mechanisms operating on the various dental structures.
Three different patterns of initial cementum and dentin lesions could be
distinguished, depending on the severity of the cariogenic attack, the
degree of sclerosis of the peripheral dentin, and the presence of calculus.
Advanced lesions were characterized by various patterns of
demineralization. In particular, a massive lateral spread of bacteria into
intertubular dentin was observed. Consequently, unaffected dentinal areas
became continuously undermined. In arrested lesions, either a partial or
complete mineralization of the intertubular dentin was apparent. Dentinal
tubules were sclerosed passively by re- or precipitation of Ca and PO4
ions. In contrast, tubules filled with ghosts of bacteria appeared
mineralized by fine-granular crystals. Our observations indicate that both
the arrestment and the remineralization of active lesions depend on (1) the
degree of active sclerosis of dentinal tubules in areas underlying the
lesion, (2) the degree of the bacterial infection of the dentin, (3) the
degree of progression of the lesions, and (4) the location of the lesions
at the various root surfaces. It is suggested that remineralization of
active lesions can occur. This supports the concept of non-invasive
treatment of root caries lesions without cavitation.
