• Biomaterials and Biomechanics in Bioengineering
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• v.2 no.2
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• pp.61-69
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• 2015

Undifferentiated stem cells are being studied to obtain information on the therapeutic potential of isolates that are produced. Dental Pulp Stem Ccell (DPSC) may provide an abundant supply of highly proliferative, multipotent Mesenchymal Stem Cells (MSC), which are now known to be capable of regenerating a variety of human tissues including bone and other dental structures. Many factors influence DPSC quality and quantity, including the specific methods used to isolate, collect, concentrate, and store these isolates once they are removed. Ancillary factors, such as the choice of media, the selection of early versus late passage cells, and cryopreservation techniques may also influence the differentiation potential and proliferative capacity of DPSC isolates. This literature review concludes that due to the delicate nature of DPSC, more research is needed for dental researchers and clinicians to more fully explore the feasibility and potential for isolating and culturing DPSCs extracted from adult human teeth in order to provide more accurate and informed advice for this newly developing field of regenerative medicine.

• Journal of the korean academy of Pediatric Dentistry
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• v.40 no.3
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• pp.185-193
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• 2013

Mineral trioxide aggregate (MTA) has recently been used as a pulpotomy medicament for primary molars. The aim of this study was to evaluate and compare the proliferation and differentiation potential of dental pulp stromal cells of permanent teeth and deciduous teeth cultured on MTA-coated surface. Human dental pulp stromal cells were obtained from human permanent premolars and deciduous teeth and cultured on MTA-coated culture plates. The cells were subjected to proliferation assay and cell cycle analysis. Their differentiation potential was evaluated by analysing changes in the mRNA expressions of runt-related transcriptional factor 2 (Runx2) and alkaline phosphatase (ALP). Morphological changes of cells in direct contact with MTA were observed using scanning electron microscopy (SEM). The proliferation rates, distribution of cell cycles and mRNA expression patterns of Runx2 and ALP were similar in both types of pulpal cells. SEM observations revealed that both types changed into more dendrite-like cells. On the surface of MTA, human dental pulp stromal cells from deciduous and permanent teeth were able to both proliferate and differentiate into cells that induce mineralization. MTA is suitable as a biocompatible pulpotomy medicament for primary teeth.

• International Journal of Oral Biology
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• v.38 no.4
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• pp.161-167
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• 2013

Human dental pulp stem cells (DPSCs) are multi-potent mesenchymal stem cells that have several differentiation potentials. An understanding of thetissues that differentiate from these cells can provide insights for future regenerative therapeutics and tissue engineering strategies. The mesiodens is the most frequent form of supernumerary tooth from which DPSCs can differentiate into several lineages similar to cells from normal deciduous teeth. Recently, it has been shown that nanoscale structures can affect stem cell differentiation. In our presentstudy, we investigated the effects of a 250-nm nanoscale ridge/groove pattern array on the osteogenic and adipogenic differentiation of dental pulp cells from mesiodenscontaining human DPSCs. To this end, the expression of lineage specific markers after differentiation induction was analyzed by lineage specific staining and RT-PCR. The nanoscale pattern arrayed surface showed apositive effect on the adipogenic differentiation of DPSCs. There was no difference between nanoscale pattern arrayed surface and conventional surface groups onosteogenic differentiation. In conclusion, the nanoscale ridge/groove pattern arrayed surface can be used to enhance the adipogenic differentiation of DPSCs derived from mesiodens. This finding provides an improved understanding of the effects of topography on cell differentiation as well as the potential use of supernumerary tooth in regenerative dental medicine.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.18 no.3
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• pp.515-527
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• 1996

The most serious problem resulting from estrogen deficiency induce osteo porosis. Recently, they make efforts to inquire a relation between hematopoietic organ and bone loss due to estrogen deficiency. Estrogen have an effect on growth and formation of skeletal system, and inhibit bone resorption under the influence of osteoblast and osteoclast, and basically inhibit the increase of hematopoietic progenitor and immune factor connected with bone resorption and prevent the osteoid formation. The purpose of this article was to observe the change of spleen and effect on hematopoietic function following estrogen administration. In this study, female rats of 150g weight was ovariectomized, after 70 days, experimental group was injected estrogen at interval of a week and sacrificed on 1, 2, 3, 4, 6 weeks. Control group was sacrificed after ovariectomy on 11, 12, 13, 14, 16 weeks without estrogen injection, and normal rats were sacrificed for harvest of spleen and femur. Paraffin sections and H&E stain was performed, and observed under light microscope. The obtained results were as follows. 1. From 11 to 12 weeks at bone marrow of control group, hematopoietic cells were decreased in comparison with normal group, and lipid infiltration was seen, and irregular bone remodelling was seen after 13 weeks. From 14 to 16 weeks, there were more decreased hematopoietic cells and lipid degeneration, and lipid degeneration of hematopoietic cells appeared. 2. All the bone marrow of experimental group, the structure of hematopoietic cells with decreased lipid infiltration was recovered from 2 weeks of estrogen adminstration and maintained to 6 weeks. 3. At spleen of control group, borders of white and red pulp was not well demarcated, and size of white pulp was decreased. 4. At spleen of experimental group, borders between white and red pulp have been well demarcated from 3 weeks of estrogen adminstration relatively, and white pulp was increased with distinct border. From above findings, we could regarded that estrogen deficiency due to ovariectomy influenced on hematopoietic cells of bone marrow and spleen, and histologic recovery of hematopoietic cells were observed after 3 weeks of estrogen adminstration even if it was not reach to normal group.

• International Journal of Oral Biology
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• v.37 no.2
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• pp.77-83
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• 2012

We investigated the pulpal response to direct pulp capping in rat molar teeth using mineral trioxide aggregate (MTA) and calcium hydroxide (CH). A palatal cavity was prepared in rat maxillary molar teeth. Either MTA or CH was placed on the exposed pulp and all cavities were restored with composite. Rats were sacrificed for histological evaluation after 12 hours and at 2, 7, 14 and 21 days. In both the MTA and CH groups, reparative dentin formation was clearly observed on histology after 14 days. The MTA-capped pulps were found to be mostly free from inflammation, and hard tissue of a tubular consistent barrier was observed. In contrast, in CH-capped teeth, excessive formation of reparative dentin toward residual pulp was evident. The pulpal cell response beneath the reparative dentin layer was examined by immunofluorescence using antibodies against DSP. After 2 days, a few DSP immunopositive cells, most of which showed a cuboidal shape, appeared beneath the predentin layer. At 7 days, DSP-immunopositive cells with columnar odontoblast-like cells were seen beneath the newly formed hard tissues. At 14 and 21 days, DSP was more abundant in the vicinity of the odontoblastic process along the dentinal tubules than in the mineralized reparative dentin. The CH group showed strong expression patterns in terms of DSP immunoreactivity. Our results thus indicate that MTA may be a more effective pulp capping material as it induces the differentiation of odontoblast-like cells and the formation of reparative dentin without the loss of residual pulp functions.

• Restorative Dentistry and Endodontics
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• v.46 no.2
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• pp.26.1-26.15
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• 2021

Objectives: The aim of the present systematic review was to investigate the cryopreservation process of dental pulp mesenchymal stromal cells and whether cryopreservation is effective in promoting cell viability and recovery. Materials and Methods: This systematic review was developed in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement and the research question was determined using the population, exposure, comparison, and outcomes strategy. Electronic searches were conducted in the PubMed, Cochrane Library, Science Direct, LILACS, and SciELO databases and in the gray literature (dissertations and thesis databases and Google Scholar) for relevant articles published up to March 2019. Clinical trial studies performed with dental pulp of human permanent or primary teeth, containing concrete information regarding the cryopreservation stages, and with cryopreservation performed for a period of at least 1 week were included in this study. Results: The search strategy resulted in the retrieval of 185 publications. After the application of the eligibility criteria, 21 articles were selected for a qualitative analysis. Conclusions: The cryopreservation process must be carried out in 6 stages: tooth disinfection, pulp extraction, cell isolation, cell proliferation, cryopreservation, and thawing. In addition, it can be inferred that the use of dimethyl sulfoxide, programmable freezing, and storage in liquid nitrogen are associated with a high rate of cell viability after thawing and a high rate of cell proliferation in both primary and permanent teeth.

• International Journal of Oral Biology
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• v.37 no.4
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• pp.167-173
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• 2012

This study investigated the genes involved in the differentiation of odontoblasts derived from human dental pulp stem cells (hDPSCs). hDPSCs isolated from human tooth pulp were validated by fluorescence activated cell sorting (FACS). After odontogenic induction, hDPSCs were analyzed investigated by Alizaline red-S staining, ALP assay, ALP staining and RT-PCR. Differential display-polymerase chain reaction (DD-PCR) was performed to screen differentially expressed genes involved in the differentiation of hDPSCs. By FACS analysis, the stem cell markers CD24 and CD44 were found to be highly expressed in hDPSCs. When hDPSCs were treated with agents such as ${\beta}$-glycerophosphate (${\beta}$-GP) and ascorbic acid (AA), nodule formation was exhibited within six weeks. The ALP activity of hDPSCs was found to elevate over time, with a detectable up-regulation at 14 days after odontogenic induction. RT-PCR analysis revealed that dentin sialophosphoprotein (DSPP) and osteocalcin (OC) expression had increased in a time-dependent manner in the induction culture. Through the use of DD-PCR, several genes were differentially detected following the odontogenic induction. These results suggest that these genes may possibly be linked to a variety of cellular process during odontogenesis. Furthermore, the characterization of these regulated genes during odontogenic induction will likely provide valuable new insights into the functions of odontoblasts.

• Restorative Dentistry and Endodontics
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• v.35 no.4
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• pp.238-245
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• 2010

Numerous cases about additional growth of roots or pulp tissue regeneration by using various intracanal medicaments in immature permanent teeth with periapical or pulpal disease have been reported. The underlying mechanism has not been clearly delineated, but it has been widely accepted that undifferentiated mesenchymal cells and stem cells are involved. Moreover, the growth and deposition of osteoid or cementoid tissues have been observed in regenerated pulp and roots. This new and non-invasive treatment has brightened the future of endodontics, and enlarged the vision of regenerative root canal treatment with multi-potent stem cells and various tissue engineering techniques.

• International Journal of Oral Biology
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• v.33 no.4
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• pp.187-195
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• 2008

Reparative dentine formation requires newly differentiated odontoblast-like cells. Therefore, identification of the molecule that stimulates the odontogenic differentiation of precursor cells in the tooth pulp will be helpful for the development of strategies to repair damaged pulp. In this study, we examined the effect of N-acetylcysteine (NAC) on the odontogenic differentiation of MDPC-23 cells, a mouse odontoblast-like cell line derived from dental papilla, and primary cultured rat dental papilla cells (RDPCs). NAC (1-30 mM) suppressed production of reactive oxygen species in MDPC-23 cells in a dose-dependent manner. Although 5 to 20 mM NAC did not alter MDPC-23 cell proliferation, 1 or 30 mM NAC significantly inhibited it. NAC enhanced mineralized nodule formation and the expression of several odontoblast differentiation-associated genes in both RDPCs and MDPC-23. This NAC stimulatory effect was significant, even at concentrations lower than 1 mM. However, NAC did not stimulate expression of bone morphogenetic protein-2, -4, or -7, which are known to enhance odontogenic differentiation. Since reactive oxygen species are also involved in the pulp toxicity of resin-based restorative materials, these results suggest that NAC may be a promising candidate for supplementation of dental restorative materials in order to enhance reparative dentine formation.

• Restorative Dentistry and Endodontics
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• v.3 no.1
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• pp.17-21
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• 1977

After a vital pulpotomy in dogs' teeth, the responses of the remaining pulp tissue under calcium hydroxide and formocresol were studied histologically. The class I and V cavities were prepared on the teeth and the pulp was amputated. Calcium hydroxide and formocresol were placed over the amputated tissue and the cavities were sealed with zine oxide eugenol cement and zinc phosphate cement. Animals. were sacrifice after 1, 2, and 3 weeks following the operation. The teeth were decalcfied, sectioned and stained with hematoxylin and eosin. Microscopic examination reveals as follows; 1. Healing of the pulp at the amputation site did not occur in the pulps treated with formocresol. 2. At one week, a thin layer of darker staining tissues just below the necrotic zone was presented in the pulps treated with formocresol. In this stage the tissues beneath the darker staining layer were normal. 3. At two weeks, the cells of the palest staining layer were showed indistinct nucleus which suggested the karyolysis and the karyorrhexis in the pulps treated with formocoresol. As reached to the middle third of the pulp, the odontoblasts were scarcely evident or missed in this stage. 4. At three weeks, the necrotic zone was reached to the middle third of the pulp canal. The cells beneath the zone showed massive infiltration of inflammatory cells in the pulps treated with formocresol. 5. Dentin bridge in the control group was deposited below the necrotic zone from the two. weeks later. 6. Normal tissues were observed ill the apical third of all. the dental pulps in all case of calcium hydroxide and formocresol.