Influence of Substrate Nature and Immobilization of Implanted Dentin Matrix Components During Induction of Reparative Dentinogenesis

Abstract

The biological effects of isolated soluble dentin extracellular matrix components on the induction of reparative dentinogenesis in exposed cavities in ferret canine teeth have been shown to be blocked by immobilizing the extracellular matrix components on nitrocellulose or Millipore membranes during implantation. This contrasts with the picture of induction of odontoblast-like cell differentiation and reparative dentin deposition on existing insoluble dentin matrix of the exposure walls when the extracellular matrix components are implanted in lyophilized form. These data indicate the importance of an existing insoluble dentin matrix in providing a substrate to potentiate the growth factor-like activity of soluble isolated dentin extracellular matrix components in the induction of reparative dentinogenesis.

Dentin matrix protein 1 induces cytodifferentiation of dental pulp stem cells into odontoblasts

“…The H&E-stained sections were examined with Zeiss LSM 510 laser scanning microscope, using the autoflorescence property of eosin (23). Samples were scanned with Ar-Kr laser using an excitation wavelength of 488 nm for green color and 568 nm for red color.…”

“…This organic matrix is generally considered to have a mineralization -regulatory capacity. 23 At the pulpal region, between the odontoblasts and the mineralized tissue, a 10-30 mm layer of predentin is located. This is a nonmineralized and acellular organic matrix, primarily collagenous in nature and rich in proteoglycans and lipids.…”

The role of transforming growth factor beta in tertiary dentinogenesis

“…4 A number of terms have been used to describe this dentin such as irregular secondary dentin, reactionary dentin, reparative dentin, and irritation dentin, all reflecting its varied etiology. Smith et al 2 has re-defined it in relation to the nature of the injury to attempt a better discrimination of the responses occurring in the dentin-pulp complex. This has led to adoption of the terms reactionary and reparative dentin to subdivide tertiary dentinogenesis into the responses seen after either survival or death of the primary odontoblast population, respectively.…”

“…Typically, this type of dentin will be seen with injury of mild intensity, such as in precavitational stages of active enamel caries and in slowly progressing dentinal lesions. 2 Slowly progressing carious lesions are characterized by an early increased mineralization of the affected dentin. This hyper mineralization occurs when the caries process is located in the enamel, before it reaches the dentin.…”

“…The most common and well-known feature of pulp repair is the formation of tertiary dentin, 1 which can be classified as being reactionary or reparative in origin, depending on the severity of the initiating response and the conditions under which the newly deposited dentin matrix was formed. 2 A number of studies have reported the presence of tertiary dentin in 63.6% of teeth with carious lesions and found that it often occurs in combination with dentinal sclerosis. 3 The formation of the tertiary dentin on the pulpal aspect of stimulated dentinal tubules occurs in human deciduous teeth 4 as well as in permanent teeth.…”