Histopathology of Root Surface Caries

Abstract

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.

Fluoride Distribution in Sound and Carious Root Tissues of Human Teeth

“…Remineralisation processes that have been reported to occur in root tissues affected by natural caries [Takuma et al, 1975;Schüpbach et al, 1990b] and artificial caries lesions [Wefel et al, 1986;Hoppenbrouwers et al, 1987b] can be a cause for true uptake of F, rather than the consolidation of endogenous F as mentioned above.The outer layer of carious root tissue contains crystals that are larger than normal [Takuma et al, 1975] and may be equivalent to the 'caries crystals' seen in enamel lesions. Such crystals are likely to scavenge F from the lesion fluid during their formation, particularly if there is an external source of F [Dunipace et al, 1994].…”

Análise do selamento marginal de restaurações realizadas após remoção de cárie radicular com o laser de Er, Cr:YSGG

“…Pesquisas têm mostrado que as lesões de cárie radicular envolvem tanto a desmineralização quanto a destruição da matriz orgânica da dentina (FRANK, 1990;FEJERSKOV, 1990;LUTZ, 1990). Alguns pesquisadores sugeriram que as fases orgânica e inorgânica são rompidas simultaneamente nas cáries radiculares (FRANK, 1990;FRANK;STEUER;HEMMERLE, 1989;).…”

Avaliação in vitro do efeito do laser de CO2, associado ou não à aplicação tópica de flúor, na redução da desmineralização de superfícies radiculares

“…Podendo uma dieta sem altas concentrações de carboidratos pode ser suficiente cariogênica para a superfície radicular se associada a um biofilme específico (KELTJENS; SCHAEKEN; VAN DER HOEVEN, 1993 A histopatologia da cárie de superfície radicular mostra uma precoce penetração bacteriana no cemento e na dentina (SEICHTER, 1987). As bactérias penetram através dos espaços mais superficiais e atingindo as camadas incrementais do cemento, por onde promovem desmineralização e desorganização (FURSETH, 1971;SCHUPBACH;GUGGENHEIM;LUTZ, 1990). Assim chegam à dentina, colonizando as fibras colágenas e provavelmente, sendo responsáveis pelo rompimento das mesmas.…”