Dentin-Pulp Complex Responses to Carious Lesions

Abstract

To understand the molecular events underlying the dentin-pulp complex responses to carious progression, we systematically analyzed tissue morphology and dentin matrix protein distribution in non-carious teeth and in teeth with enamel and dentin caries. Dentin matrix proteins analyzed included collagen type I, phosphophoryn (PP) and dentin sialoprotein (DSP), all of which play decisive roles in the dentin mineralization process. Human non-carious and carious third molar teeth were freshly collected, demineralized, and processed for hematoxylin and eosin staining. The ABC-peroxidase method was used for immunohistochemical staining of collagen type I, PP and DSP proteins using specific antibodies. In situ hybridization was also performed. In contrast to elongated odontoblasts in non-carious teeth, odontoblasts subjacent to dentin caries were cuboidal and fewer in number. The predentin zone was also dramatically reduced in teeth with dentin caries. The staining intensity for collagen type I, PP and DSP in the dentin-pulp complex increased progressively from non-carious teeth, to teeth with enamel and dentin caries. In situ hybridization studies showed DSP-PP mRNA expression in odontoblasts and dental pulp that was consistent with our immunohistochemical results. These results suggest that carious lesions stimulate the dentin-pulp complex to actively synthesize collagen type I, PP and DSP proteins. This response to carious lesions is likely to provide a basis for reparative and/or reactionary dentin formation.

Glial Network Responses to Polymicrobial Invasion of Dentin

“…An important aspect of the adaptive response of odontoblasts to carious insult is the synthesis of reactionary dentin [Smith et al, 1995[Smith et al, , 2001. The synthesis of reactionary dentin demands up-regulation of metabolic activity of odontoblasts [Lee et al, 2006;Farahani et al, 2010]. Carious insult results, initially, in up-regulation of the message for HIF-1α, interpreted as indicating hypoxic stress in responding odontoblasts.…”

“…These odontoblast-like cells then produce reparative dentin underlying the affected dentinal tubules [Hargreaves and Abbott, 2005;Lee et al, 2006]. Reparative dentin is atubular, amorphous and irregular [Magloire et al, 1992].…”

Partial Removal of Carious Dentine: A Multicenter Randomized Controlled Trial and 18-Month Follow-Up Results

“…Copyright © 2012 S. Karger AG, Basel The management of deep caries lesions has been discussed extensively in the literature [Magnusson and Sundell, 1977;Leksell et al, 1996;Bjørndal et al, 1997;Bjørndal and Thylstrup, 1998;Weerheijm et al, 1999;Maltz et al, 2002;Massara et al, 2002;Paddick et al, 2005;Pinto et al, 2006;Ricketts et al, 2006]. These papers cover different topics, including the appropriate instruments for removing carious tissues, the amount of decayed tissue that needs to be removed [Bjørndal and Thylstrup, 1998], and the interaction between pulp and dentine [Massara et al, 2002;McLachlan et al, 2003;Lee et al, 2006]. …”

Adaptive Calcified Matrix Response of Dental Pulp to Bacterial Invasion Is Associated with Establishment of a Network of Glial Fibrillary Acidic Protein+/Glutamine Synthetase+ Cells

“…7 Despite extensive research, the response of odontoblasts to this microbial ingress remains poorly characterized. 8 Exposure of differentiated odontoblasts in primary cultures to bacterial products reduces dentin forming capacity. 9 This contrasts with the observed deposition of reactionary dentin with implications for external regulation of odontoblast function.…”