• Restorative Dentistry and Endodontics
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• 제38권4호
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• pp.227-233
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• 2013

Objectives: The purpose of the study was to evaluate human dental pulp response to pulpotomy with calcium hydroxide (CH), mineral trioxide aggregate (MTA), and calcium enriched mixture (CEM) cement. Materials and Methods: A total of nine erupted third molars were randomly assigned to each pulpotomy group. The same clinician performed full pulpotomies and coronal restorations. The patients were followed clinically for six months; the teeth were then extracted and prepared for histological assessments. The samples were blindly assessed by an independent observer for pulp vitality, pulp inflammation, and calcified bridge formation. Results: All patients were free of clinical signs/symptoms of pulpal/periradicular diseases during the follow up period. In CH group, one tooth had necrotic radicular pulp; other two teeth in this group had vital uninflamed pulps with complete dentinal bridge formation. In CEM cement and MTA groups all teeth had vital uninflamed radicular pulps. A complete dentinal bridge was formed beneath CEM cement and MTA in all roots. Odontoblast-like cells were present beneath CEM cement and MTA in all samples. Conclusions: This study revealed that CEM cement and MTA were reliable endodontic biomaterials in full pulpotomy treatment. In contrast, the human dental pulp response to CH might be unpredictable.

• 대한치과보존학회:학술대회논문집
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• 대한치과보존학회 2003년도 제120회 추계학술대회 제 5차 한ㆍ일 치과보존학회 공동학술대회
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• pp.583-583
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• 2003

Recent study reported whether the cultured human pulp cells increase IL-8 secretion in response to SP stimulation22). In the present study, whether induction of IL-8 or MCP-1 in pulp tissue can be detected using enzyme-linked immunosorbent assay(ELISA) with ex vivo pulpal explants exposed to neuropeptides in culture and the IL-8 expression using immunohistochemical analysis with the ex vivo pulpal explants exposed to neuropeptides was evaluated. To investigate further mechanisms that may contribute to leukocyte recruitment in lesions of endodontic origin, the differential expression of IL-8 and MCP-1 by human dental pulp tissues stimulated in vitro by the Substance P was examined.(omitted)

• Restorative Dentistry and Endodontics
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• 제27권1호
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• pp.1-11
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• 2002

Immune responses associated with bacterial infection involve various inflammatory cells. Clinical symptoms and pathologic features are particularly influenced by the predominant cells Among inflammatory cells, T cells have the heterogenity. T cells may develop into the mature cells expressing the cell surface markers with different functions and T helper cells are categorized into Th1 and Th2 cells based on their different patterns of cytokine production. The objective of this study was to investigate the change of expression of surface markers on T cells and the Th1/Th2 immune response in pulpal inflammation associated with specific bacteria. We experimentally induced pulpal inflammation in rat incisors by drilling without coolant and innoculated with Streptococcus mutans (S.M. group), Porphyromonas endodontalis (P.E. group), or only sterile cotton (control group). After 1, 2, and 5 days, mandibular incisors were extracted and the pulp tissues were extirpated The expressions of IL-2 recepters (CD25) and ICAM-1 (CD54) on CD4+ and CD8+ cells in the pulps were determined using a flow cytometer, and the concentration of IL-2, IFN-$\gamma$ and IL-4 was measured by enzyme-linked immunosorbent assay. The results were as follows: 1 In the S.M. group, CD4+ cells were more increased at 2nd day than 1st day and in the P.E. group, CD8+ cells were more increased at 2nd day than 1st day. 2. The percentages of CD4+, CD4+25+ and CD4+54+ cells were decreased in the pulp tissues at 5th day after irritation in all groups. 3. The ratios of CD4+/CD8+, CD4+/CD4+25+ and CD4+/CD4+54+ in the pulps at 2nd day after irritation by P. endodontalis were significantly lower than the other groups. 4. The higher concentrations of IFN-$\gamma$ than IL-4 in the pulps at 2nd day after irritation by P. endodontalis showed that T helper 1 reaction were predominant in the early stage of the pulpal inflammation induced by P. endodontalis. 5. The higher concentrations of IL-4 than IFN-$\gamma$ in the pulps at 1st day and 5th day after irritation by S. mutans were measured but the differences were not significant.

• Restorative Dentistry and Endodontics
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• 제44권2호
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• pp.20.1-20.8
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• 2019

Objectives: To achieve pulp-dentin complex regeneration with tissue engineering, treatment efficacies and safeties should be evaluated using in vivo orthotopic transplantation in a sufficient number of animals. Mice have been a species of choice in which to study stem cell biology in mammals. However, most pulp-dentin complex regeneration studies have used large animals because the mouse tooth is too small. The purpose of this study was to demonstrate the utility of the mouse tooth as a transplantation model for pulp-dentin complex regeneration research. Materials and Methods: Experiments were performed using 7-week-old male Institute of Cancer Research (ICR) mice; a total of 35 mice had their pulp exposed, and 5 mice each were sacrificed at 1, 2, 4, 7, 9, 12 and 14 days after pulp exposure. After decalcification in 5% ethylenediaminetetraacetic acid, the samples were embedded and cut with a microtome and then stained with hematoxylin and eosin. Slides were observed under a high-magnification light microscope. Results: Until 1 week postoperatively, the tissue below the pulp chamber orifice appeared normal. The remaining coronal portion of the pulp tissue was inflammatory and necrotic. After 1 week postoperatively, inflammation and necrosis were apparent in the root canals inferior to the orifices. The specimens obtained after experimental day 14 showed necrosis of all tissue in the root canals. Conclusions: This study could provide opportunities for researchers performing in vivo orthotopic transplantation experiments with mice.

• 대한소아치과학회지
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• 제38권3호
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• pp.276-283
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• 2011

최근 미성숙 영구치의 치근단 유두에서 존재하는 미분화 줄기세포가 새로 발견되었고 이 줄기세포들은 치근 상아질의 형성에 관여하는 법랑모세포의 근원으로 보여진다. 미성숙 영구치를 다룰때 이 줄기세포들의 보존은 치근의 지속적인 형성을 완성시키게 한다. 따라서 치근단 염증을 동반한 미성숙 영구치에서 치근단의 최소한의 침습으로 임상 및 방사선적 치유 양상을 관찰할 수 있었기에 보고하고자 한다. 본 증례는 조선대학교 치과대학병원 소아치과에 내원한 만 10세 남아(하악 우측 소구치), 만 8세 여아(상악 좌측 소구치)에서 임상 및 방사선 검사결과 치수괴사와 치근단 농양으로 진단된 영구치에서 치근단부위의 기구조작을 제한하고 MTA(Mineral Trioxide Aggregate)를 치수강내에 적용하였다. 정기적으로 관찰한 결과 치근단 농양의 치유와 치근 발육 및 성장의 양상이 관찰되었다. 치수괴사와 치근단 농양을 가진 영구치에서 치근단부위의 치수 및 치유두를 보호함으로써 관찰기간동안 양호한 예후를 보였으며, 이는 어린환자의 미성숙영구치에서 보존적 치수치료의 시도에 대한 보다 많은 임상적 검증 및 장기간의 고찰이 필요할 것이다.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제36권3호
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• pp.186-196
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• 2010

Introduction: The first aim of this study was to isolate the dental tissue-derived stem cells from the dental follicle (DF), dental pulp (DP), and root apical papilla (RAP) of the extracted wisdom teeth. Second was to evaluate their characterization with the expressions of transcription factors and cell surface markers. Finally, their ability of the in vitro multi-lineage differentiations into osteogenic and adipogenic cells were compared, respectively. Materials and Methods: Dental tissues, including dental follicle, dental pulp, and root apical papilla, were separated in the extracted wisdom teeth. These three dental tissues were cultured in Dulbecco’s modified Eagle’s medium (DMEM) with supplements, respectively. After passage 3, the homogeneous shaped dental tissue-derived cells were analyzed the expression of transcription factors (Oct-4, Nanog and Sox-2) and cell surface markers (CD44, CD90 and CD105) with reverse transcription polymerase chain reaction (RT-PCR) and fluorescence-activated cell sorting (FACS) analysis. In order to evaluate in vitro multi-lineage differentiations, the culture media were changed to the osteogenic and adipogenic induction mediums when the dental tissue-derived cells reached to passage 3. The characteristics of these three dental tissue-derived cells were compared with immunohistochemistry. Results: During primary culture, heterogenous and colony formatted dental tissue-derived cells were observed in the culture plates. After passage 2 or 3, homogenous spindle-like cells were observed in all culture plates. Transcription factors and mesenchymal stem cell markers were positively observed in all three types of dental tissue-derived cells. However, the quantity of expressed transcription factors was most large in RAP-derived cells. In all three types of dental tissue-derived cells, osteogenic and adipogenic differentiations were observed after treatment of specific induction media. In vitro adipogenic differentiation was similar among these three types of cells. In vitro osteogenic differentiation was most strongly and frequently observed in the RAP-derived cells, whereas rarely osteogenic differentiation was observed in the DP-derived cells. Conclusion: These findings suggest that three types of human dental tissue-derived cells from extracted wisdom teeth were multipotent mesenchymal stem cells, have the properties of multi-lineage differentiations. Especially, stem cells from root apical papilla (SCAP) have much advantage in osteogenic differentiation, whereas dental follicle cells (DFCs) have a characteristic of easy adipogenic differentiation.

• The Journal of Advanced Prosthodontics
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• 제7권1호
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• pp.21-26
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• 2015

PURPOSE. To evaluate the cytotoxicity of temporary luting cements on bovine dental pulp-derived cells (bDPCs). MATERIALS AND METHODS. Four different temporary cements were tested: Rely X Temp E (3M ESPE), Ultratemp (Ultradent), GC Fuji Temp (GC), and Rely X Temp NE (3M ESPE). The materials were prepared as discs and incubated in Dulbecco's modified eagle's culture medium (DMEM) for 72 hours according to ISO 10993-5. A real-time cell analyzer was used to determine cell vitality. After seeding $200{\mu}L$ of the cell suspensions into the wells of a 96-well plate, the bDPCs were cured with bioactive components released by the test materials and observed every 15 minutes for 98 hours. One-way ANOVA and Tukey-Kramer tests were used to analyze the results of the proliferation experiments. RESULTS. All tested temporary cements showed significant decreases in the bDPCs index. Rely X Temp E, GC Fuji Temp, and Rely X Temp NE were severely toxic at both time points (24 and 72 hours) (P<.001). When the cells were exposed to media by Ultratemp, the cell viability was similar to that of the control at 24 hours (P>.05); however, the cell viability was significantly reduced at 72 hours (P<.001). Light and scanning electron microscopy examination confirmed these results. CONCLUSION. The cytotoxic effects of temporary cements on pulpal tissue should be evaluated when choosing cement for luting provisional restorations.

• Molecules and Cells
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• 제38권7호
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• pp.604-609
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• 2015

The active metabolite of vitamin D such as $1{\alpha}$,25-dihydroxyvitamin ($D_3(1{\alpha},25(OH)_2D_3)$ is a well-known key regulatory factor in bone metabolism. However, little is known about the potential of vitamin D as an odontogenic inducer in human dental pulp cells (HDPCs) in vitro. The purpose of this study was to evaluate the effect of vitamin $D_3$ metabolite, $1{\alpha},25(OH)_2D_3$, on odontoblastic differentiation in HDPCs. HDPCs extracted from maxillary supernumerary incisors and third molars were directly cultured with $1{\alpha},25(OH)_2D_3$ in the absence of differentiation-inducing factors. Treatment of HDPCs with $1{\alpha},25(OH)_2D_3$ at a concentration of 10 nM or 100 nM significantly upregulated the expression of dentin sialophosphoprotein (DSPP) and dentin matrix protein1 (DMP1), the odontogenesis-related genes. Also, $1{\alpha},25(OH)_2D_3$ enhanced the alkaline phosphatase (ALP) activity and mineralization in HDPCs. In addition, $1{\alpha},25(OH)_2D_3$ induced activation of extracellular signal-regulated kinases (ERKs), whereas the ERK inhibitor U0126 ameliorated the upregulation of DSPP and DMP1 and reduced the mineralization enhanced by $1{\alpha},25(OH)_2D_3$. These results demonstrated that $1{\alpha},25(OH)_2D_3$ promoted odontoblastic differentiation of HDPCs via modulating ERK activation.

• Natural Product Sciences
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• 제19권1호
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• pp.54-60
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• 2013

Rhus verniciflua Stokes (Anacadiaceae) is a plant that is native to East Asian countries, such as Korea, China, and Japan, and it has been found to exert various biological activities including antioxidative, anti-aggregatory, anti-inflammatory, anti-mutagenic, and apoptotic effects. Sulfuretin is one of the major flavonoid component isolated from the heartwood of R. verniciflua. Reactive oxygen species (ROS), produced via dental adhesive bleaching agents and pulpal disease, can cause oxidative stress. In the present study, we isolated sulfuretin from R. verniciflua and demonstrated that sulfuretin possesses cytoprotective effects against hydrogen peroxide ($H_2O_2$)-induced dental cell death. $H_2O_2$ is a representative ROS and causes cell death through necrosis in human dental pulp (HDP) cells. $H_2O_2$-induced cytotoxicity and production of ROS were blocked in the presence of sulfuretin, and these effects were dose dependent. Sulfuretin also increased heme oxygenase-1 (HO-1) protein expression. In addition, to determine whether sulfuretin-induced HO-1 expression mediated this cytoprotective effect, HDP cells were cotreated with sulfuretin in the absence or presence of SnPP, an inhibitor of HO activity. Sulfuretin-dependent HO-1 expression was required for suppression of $H_2O_2$-induced HDP cell death and ROS generation. These results indicate that sulfuretin-dependent HO-1 expression was required for the inhibition of $H_2O_2$-induced cell death and ROS generation. In addition, sulfuretin may be used to prevent functional dental cell death and thus may be useful as a pulpal disease agent.

• Restorative Dentistry and Endodontics
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• 제40권4호
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• pp.290-298
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• 2015

Objectives: Sodium hypochlorite (NaOCl) is an excellent bactericidal agent, but it is detrimental to stem cell survival, whereas intracanal medicaments such as calcium hydroxide ($Ca[OH]_2$) promote the survival and proliferation of stem cells. This study evaluated the effect of sequential NaOCl and $Ca(OH)_2$ application on the attachment and differentiation of dental pulp stem cells (DPSCs). Materials and Methods: DPSCs were obtained from human third molars. All dentin specimens were treated with 5.25% NaOCl for 30 min. DPSCs were seeded on the dentin specimens and processed with additional 1 mg/mL $Ca(OH)_2$, 17% ethylenediaminetetraacetic acid (EDTA) treatment, file instrumentation, or a combination of these methods. After 7 day of culture, we examined DPSC morphology using scanning electron microscopy and determined the cell survival rate with 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay. We measured cell adhesion gene expression levels after 4 day of culture and odontogenic differentiation gene expression levels after 4 wk using quantitative real-time polymerase chain reaction. Results: DPSCs did not attach to the dentin in the NaOCl-treated group. The gene expression levels of fibronectin-1 and secreted phosphoprotein-1 gene in both the $Ca(OH)_2$- and the EDTA-treated groups were significantly higher than those in the other groups. All $Ca(OH)_2$-treated groups showed higher expression levels of dentin matrix protein-1 than that of the control. The dentin sialophosphoprotein level was significantly higher in the groups treated with both $Ca(OH)_2$ and EDTA. Conclusions: The application of $Ca(OH)_2$ and additional treatment such as EDTA or instrumentation promoted the attachment and differentiation of DPSCs after NaOCl treatment.