• Journal of Oral Medicine and Pain
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• v.40 no.4
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• pp.146-154
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• 2015

Purpose: The purpose of present study was to develop a method for assessing the chronological age of Korean adults based on the relationship between age and size of pulp cavity using dental radiographs of mandibular first molars. Methods: A total of 325 dental radiographs of Korean adults with known age and gender were selected for the study (199 males and 126 females) which were taken in the period between January 2009 and June 2014 at the Pusan National University Dental Hospital. The measurements were carried out on both orthopantomographs (OPGs) and intraoral periapical radiographs of mandibular first molar and the following ratios were calculated: pulp chamber floor height ratio (F/L), pulp chamber ceiling height ratio (R/L), and pulp chamber depth ratio (D/L). Results: The ratios of measurements on intraoral periapical images of mandible first molar generally produce more reliable data than the measurements on OPGs. The pulp chamber floor height ratio and pulp chamber thickness ratio showed significant correlation with age, whereas the pulp chamber ceiling height ratios showed weak correlation with age. It was found that the best correlations between the ratios and age were found for pulp chamber thickness ratios (r=-0.731 to -0.751). The multiple regression models were derived using 3 ratios that were significantly correlated with age. The determination coefficients ($R^2$) of the models ranged from 0.556 to 0.596. Conclusions: Our results indicate that the pulp chamber thickness and pulp chamber floor height in mandibular first molar are an age-dependent variable in adults which can be used to estimate age with reasonable accuracy. The higher image quality of dental radiographs will probably narrow the age estimation error and improve dental age estimation.

• Journal of Periodontal and Implant Science
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• v.35 no.2
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• pp.311-319
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• 2005

In order to examine the effects of advanced periodontitis on the dental pulps, 38 extracted human teeth were examined histologically. The 38 teeth had a positive or negative state in the electric pulp test(EPT). In addition, almost of the 38 teeth had a deep pocket and severe mobility, and floating state. A medical and dental history was elicited. The extracted teeth fixed in 10% neutral formalin solution. The general tissue processing method was followed. The tissue block including the teeth was prepared for optical microscopy using hematoxillin-eosin staining. Among the 38 periodontally involved teeth, the dental pulps were respectively intact in 12(31%), and a pulp stone(or linear calcifications) was found in 18 teeeth(47%). In addition, 17 teeth(44%) had pulps exhibiting inflammatory reactions with varying intensities, such as hyperemia, pulp abscess, pulp necrosis. Among the 38 periodontally involved teeth, 37 teeth tested a positive to the EPT, and 7 teeth tested negative. The EPT positive 37 teeth had various histological features such as 7 normal pulp(18%), 17 pulp stone(44%), 1 hyperemia (2%), 9 pulpitis(23%), 5 root resorption(13%), 3 pulp abscess(7%), and 3 pulp necrosis(7%), In conclusion, it is suggested that in the EPT positive teeth, advanced periodontally involved teeth can cause inflammation of the dental pulp.

• The Journal of the Korean dental association
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• v.19 no.6 s.145
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• pp.529-533
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• 1981

The effect of insulin on the collagen metabolism in dental pulp and gingiva was studied using Sprague-Dawley rat and ³H-proline was injected intraperitoneally and then sacrificed according to predetermined schedule. Lower incisor pulp and gingiva were removed immediatedly and hydrolysed with acid. After digestion, proline and hydroxyproline were separated and analysed quantitatively employing thin-layer chromatography and radioactivity of each amino acid was counted by liquid scintillation counter. The label incorporated into lower incisor pulp and gingiva and radioactivity of ³H-hydroxyproline were increased in insulin administered group. And disappearance rate of ³H-hydroxyproline was decreased. Those results indicated that amino acid, I.e. proline transport and collagen biosynthesis were increased in dental pulp and gingiva by insulin administration.

• The Journal of the Korean dental association
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• v.54 no.8
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• pp.658-665
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• 2016

Treatment of immature permanent teeth with irreversibly damaged pulp has been challenging in dental practice because of the lack of apical constriction, thin dentinal walls, and short roots. This may lead to the extrusion of filling materials, and fracture of the root due to its more fragile feature during shaping of the root canal. Apexification with calcium hydroxide or MTA is one of the treatment options for these cases. Although favorable results of apexification have been reported, these treatment procedures do not guarantee the increase of root length and/or width even after a long term period. Thus, treated teeth are still prone to fractures. Recently, pulp revascularization has been proposed as an alternative treatment for immature teeth with necrotic pulp and periapical pathosis. Pulp revascularization allows the stimulation of the apical development and the root maturation. There have been many treatment protocols using various materials such as antibiotics and calcium hydroxide medicament. In this case report, literature review about pulp revascularization and two related cases are presented.

• Journal of Oral Medicine and Pain
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• v.8 no.1
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• pp.83-96
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• 1983

The purpose of this study was detection of the poison from the acute cyanide and aresenic poisoned rabbits, The author administered KCN and $AS_2O_3$ to rabbits and caused acute poisoning, then analysed the teeth, dental pulp and jaws of the rabbits chemicotoxicologically and observed the specimen histopathologically. 1. In subcutaneausly injected group of KCN, a large amount of cyanide was detected in blood and lung and a small amount of cyanide was detected in teeth and dental pulp, but was not detected in jaws. 2. In orally administered group of KCN a large amount of cyanide was detected in blood, lung and dental pulp and a small amount of cyanide was detected in teeth and jaws. 3. In orally administered group of $AS_2O_3$, arsenic was detected markedly in teeth and jaws, but was detected a little in dental pulp. 4. In orally administered and heat-treated group of KCN, the author could detected cyanide in teeth, dental pulp and jaws. 5. In suvcutanelusly injected group of KCN, orally administered group of KCN and orally dministered group of $AS_2O_3$, histopathologic findings showed the congestion and hemorrhage in dental pulp. 6. In orally administerd group of $AS_2O_3$, the congestion and hemorrhage in buccal mucosa were found and the basal cell degeneration and fibrosis were found in palatal mucosa.

• International Journal of Oral Biology
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• v.45 no.4
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• pp.197-203
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• 2020

Mesenchymal stem cells in the dental pulp exhibit a tendency for differentiation into various dental lineages and hold great potential as a major conduit for regenerative treatment in dentistry. Although they can be readily isolated from teeth, the exact characteristics of these stem cells have not been fully understood so far. When compared to two-dimensional (2D) cultures, three-dimensional (3D) cultures have the advantage of enriching the stem cell population. Hence, 3D-organoid culture and 3D-sphere culture were applied to dental pulp cells in the current study. Although the establishment of the organoid culture proved unsuccessful, the 3D-sphere culture readily initiated the stable generation of cell aggregates, which continued to grow and could be passaged to the second round. Interestingly, a significant increase in SOX2 expression was detected in the 3D-spheroid culture compared to the 2D culture. These results indicate the enrichment of the stemness-high population in the 3D-sphere culture. Thus, 3D-sphere culture may act as a link between the conventional and 3D-organoid cultures and aid in understanding the characteristics of dental pulp stem cells.

• Imaging Science in Dentistry
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• v.35 no.1
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• pp.9-14
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• 2005

Purpose : To observe the histopathological changes in the pulp tissues of mandibular molars in streptozotocin-induced diabetic rats after irradiation. Materials and Methods : The male Sprague-Dawley rats weighing approximately 250 gm were divided into four groups: control, diabetes, irradiation, and diabetes-irradiation groups. Diabetes mellitus was induced in the rats by injecting streptozotocin. Rats in control and irradiation groups were injected with citrate buffer only. After 5 days, the head and neck region of the rats in irradiation and diabetes-irradiation groups were irradiated with a single absorbed dose of 10 Gy. All the rats were sacrificed at 3, 7, 14, 21, and 28 days after irradiation. The specimen including the mandibular molars were sectioned and observed using a histopathological method. Results : In the diabetes group, capillary dilatation was observed. However, there was no obvious morphologic alteration of the odontoblasts. In the irradiation group, generalized necrosis of the dental pulp tissues was observed. Vacuolation of the odontoblasts and dilatation of the capillaries were noted in the early experimental phases. In the diabetes-irradiation group, generalized degeneration of the dental pulp tissues was observed. Vacuolation of the dental pulp cells and the odontoblasts was noted in the late experimental phases. Conclusion : This experiment suggests that dilatation of the capillaries in the dental pulp tissues is induced by diabetic state, and generalized degeneration of the dental pulp tissues is induced by irradiation of the diabetic group.

• Restorative Dentistry and Endodontics
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• v.24 no.1
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• pp.180-186
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• 1999

Eugenol has been reported to reduce odontogenic pain and is known to have a structure similar to capsaicin, a potent stimulant of certain nociceptors. We have hypothesized that the analgesic effect of eugenol may be due, in part, to inhibition of capsaicin-sensitive nociceptors. To test this hypothesis, we evaluate whether eugenol inhibits capsaicin-sensitive release of immunoreactive calcitonin generated peptide(iCGRP) from bovine dental pulp. Freshly extracted bovine incisors were transported to the lab. on ice, Spilitted and pulp tissue was removed. The tissue was chopped into 200${\mu}m$ slices. Dental pulp was superfused(340 ${\mu}l/min$) in vitro with oxygenated Kreb's buffer. Eugenol and vehicle(0.02% 2-hydroxyl-${\beta}$-cyclodextrin) were administered prior to stimulation of pulp with capsaicin and iCGRP was measured by RIA. The results were as follows: 1. Administration of eugenol has no effect on basal release of iCGRP. 2. In the vehicle treated group, capsaicin evoked a 2.5-fold increase over basal iCGRP levels. 3. Administration of eugenol(600 ${\mu}M$) reduced capsaicin evoked release of iCGRP by more than 40%(153.4${\pm}$41.1% vs 258.9${\pm}$21.7%). 4. 2-hydroxylpropyl-${\beta}$-cyclodextrin of less than 0.02% is found to be an effective vehicle to dissolve eugenol without evoking iCGRP release from dental bovine pulp. These data indicate that eugenol inhibits pulpal capsaicin-sensitive fibers and suggest that intracanal medicament of eugenol may relieve pain, in part, by this mechanism.

• The Journal of the Korean dental association
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• v.25 no.7 s.218
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• pp.665-672
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• 1987

In order to study the effects of advanced periodontitis on pulps, 36 human teeth were examined histologically. In addition, a medical and dental history was elicited. The pulps were intact, uninflammed in only 9 teeth (25%) of 36 periodontally involved teeth. 27 teeth (75%) had pulps exhibiting inflammatory lesions of varing intensities. Of 27 teeth with pathological pulp tissue alterations, focal reversible pulpitis was found in 4 teeth, chronic pulpitis in 13 teeth, pulp abscess in 6 teeth, and pulp necrosis in 4 teeth. These observations appeared to indicate that teeth with dvanced periodontitis produce a high incidence of degenertion and inflammation of the pulp. Responses to electric pulp test were not found to be reliable indicators of the state of the pulp in periodontally involved teeth.

• Restorative Dentistry and Endodontics
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• v.30 no.3
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• pp.193-203
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• 2005

The induction of the IL-8 and MCP-1 by the stimulation of Substance P and TNF-${\alpha}$ (IL-8 agonist) and the specificity for SP using Spantide (SP antagonist) in the dental pulp tissues was measured quantitatively. In addition, the secretion of the IL-8 in the human dental pulp tissue 36 hrs after the stimulation of SP was observed after the stimulation of SP qualitatively. According to this study the results were as follows: 1. There was the significant IL-8 induction at 36 h after SP (10$^{-4}$M) stimulation of the pulp tissue comparing with the unstimulated dental pulp tissues (p < 0.05) . IL-8 irnmunostaining was weakly detected along the periphery of the pulp tissue after Mock stimulation and IL-8 immunostaining was detected around the fibroblast in the pulp tissue 36h After SP (10$^{-4}$M) stimulation, 2. The secretion of MCP-1 from the dental pulp tissues comparing with Mock stimulation was induced at 36 hrs after TNF-$\alpha$ (40 ng/ml) stimulation, but no induction with SP(10$^{-4}$M) TNF-${\alpha}$ (40 ng/ml) did not induce the IL-8 secretion from the pulp tissue, weak IL-8 imrnunostaining was detected along the periphery of the pulp tissue 3. Spantide (10$^{-5}$M) inhibited IL-8 induction from the pulp tissues 36 h after SP (10$^{-4}$M) stimulation These results suggest that SP significantly induces IL-8 recruiting neutrophils in localized human dental pulp tissue MCP-1 appears to be less involved in the early establishment of pulpal inflammation in response to irritation such as mechanical insult of dentin. SP may have positive relation with the inflammation of the human dental pulp tissues.