• Journal of the korean academy of Pediatric Dentistry
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• v.24 no.3
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• pp.518-536
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• 1997

The purpose of the present study was to analyze the pulpal tissue reactions to several capping materials. 8 adult Mongrel dogs and 4 different capping materials (G I : Calcium hydroxide, G II : Bonding resin, G III : Glass ionomer liner, G IV : Bioactive ceramic) we-reused in the study. The results can be summarized as follows : 1. The formation of hard tissue barrier was observed to begin after 2 weeks in all groups with various forms or positions. 2. According to the result of statistical analysis, G I and G IV showed significantly higher degree of inflammation than G II, G III in 1-week samples(p<.05). And in 2-week samples, G I showed higher degree of inflammation than G II, G IV with statistical significance(p<.05). Howere, these inflammatory reactions have gradually dimiished with time resulting in negligible difference between groups. 3. No bacterial penetration was observed in any group. 4. Hard tissue formation was evident in all groups after 2 weeks regardless of material type in this experiment. Conclusion can be drawn from the above-mentioned results that the perfect marginal sealing after pulp capping procedure is thought to be the most important factor in determining the propgnosis of direct pulp capping.

• Restorative Dentistry and Endodontics
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• v.21 no.1
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• pp.366-374
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• 1996

The purpose of this study was to investigate whether D-myo-inositol-l,2,6-trisphosphate (PP56) can effectively antagonize vasoconstriction caused by neuropeptide Y in the dental pulp, and to understand involvement of neuropeptide Y in the regulation of microcirculation in the dental pulp with the aim of elucidating neurogenic inflammation. Experiments were performed on 7 cats anesthetised with sodium pentobarbital, and neuropeptide Y and a neuropeptide Y antagonist PP56 were injected close intra-arterially into the dental pulp. The probe of laser Doppler flowmeter was placed on the buccal surface of ipsilateral canine teeth to the drug administration and pulpal blood flow was measured. Intra-arterial injection of neuropeptide Y (1.3-$2.0\;{\mu}g$/kg) resulted in pulpal blood flow decrease of $37.73{\pm}5.73%$(mean${\pm}$SEM) (n=9). Intra-arterial injection of PP56(0.3 mg/kg) alone changed pulpal blood flow little by 1.03 % reduction. The effect of neuropeptide Y in the presence of PP56 resulted in significantly less decreases in pulpal blood flow ranging from $27.17{\pm}5.37$ to $16.63{\pm}3.48%$ from control as compared with neuropeptide Y alone(n = 13). In effect, PP56 attenuated pulpal blood flow caused by neuropeptide Y. Results of the present study have provided evidences that a non-peptide PP56 is capable of antagonizing vasoconstriction caused by neuropeptide Y in the feline dental pulp. In addition, they show functional evidences that neuropeptide Y plays an active role in modulating the microcirculation of the dental pulp.

• Proceedings of the KACD Conference
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• 2003.11a
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• pp.548-549
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• 2003

Neurogenic inflammation has been recognized to play an important role in initiating and sustaining of pulp inflammation. The pulpal innervation may modulate several aspects of the inflammatory response via secretion of neuropeptides. In this present study, these neuropeptides that may be questioned about roles in recruiting leukocytes by inducing the release of the chemokine IL-8 in the pulp during inflammation were tested. The response of human pulp cells in releasing IL-8 after the stimulation with SP and/or CGRP were investigated.(omitted)

• Journal of the korean academy of Pediatric Dentistry
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• v.37 no.4
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• pp.488-496
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• 2010

Dens evaginatus is a tooth with cylindrical enamel projection which forms a nodule on occlusal surface. It could be explained as outward overgrowth of inner enamel epithelium or localized hyperplasia of pulpal mesenchymal tissue during tooth development. A problem is that it is likely to be worn out or fractured by mastication ensuing pulpal inflammation. It is occasionally found on the lingual surface of upper anterior teeth as well, called talon cusp. Dens invaginatus is a tooth with deep lingual pit made by invagination of lingual enamel epithelium during tooth development while it is considered normal in terms of size and shape. Radiographically, a part of cervical enamel shows inward growth forming cavity and it is reasonable to say that the base is possibly open to pulpal cavity since they are very close. Talon cusp and dens invaginatus are relatively common abnormality of shape. However it becomes the opposite if the two exist in the same tooth. Once the talon cusp is broken by occlusal force or fissure between cusps is decayed, the complicated structure of canals makes the pulpal treatment difficult. Preventive treatments such as occlusal equilibrium and sealant, and regular oral examination should be preceded and thorough understanding of canal shape, using radiography, is required when pulpal treatment is necessary. This report is about a 9- year-old boy(lower left central incisor), a 8-year-old girl(upper right central incisor), and a 7-year-old boy(upper right central incisor), who have dens invaginatus and talon cusp in the same teeth. The first and the second patients are under pulpal treatments, and the last one is being observed showing no pathologic impressions.

• Restorative Dentistry and Endodontics
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• v.30 no.6
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• pp.470-476
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• 2005

The purpose of this Study was to invest)gate the function or calcitonin gene-related peptide (CGRP) in regulatory mechanism of pulpal microcirculation with the aim of elucidating neurogenic inflammation. Experiments were performed on twelve cats under general anesthesia. CGRP was administered through the femoral vein to see the systemic Influence and through the external carotid artery to see the local effect. Sympathetic nerve to the dental pulp was stimulated electrically and pulpal blood flow (PBF) was measured with a laser Doppler flowmeter on the canine teeth to the drug administration. The paired variables of control and experimental data were compared by paired t-test and differences with p < 0.05 were considered statistically significant. Systemic administration of CGRP $(0.3{\mu}g/ka)$ exerted decreases in systemic blood pressure and caused changes in PBF with an initial increase i311owed by decrease and a move marked second increase and decrease. Close intra-arterial (i.a.) injection of CCRP $(0.03{\mu}g/kg)$ resulted in slight PBF increase. The effect of CGRP resulted in no significant increase in PBF in the presence of $CGRP_{8-37}$. The electrical stimulation of the sympathetic nerve alone resulted in PBF decreases. The j.a. administration of CGRP following the electrical stimulation of the sympathetic nerve compensated the decreased PBF. Therefore, CGRP effectively blocked the sympathetic nerve stimulation-induced PBF decrease. Results of the present study have provided evidences that even though the local vasodilatory function of CGRP are weak, CCRP is effectively involved in blocking the vasoconstriction caused by sympathetic nerve stimulation in the feline dental pulp.

• Journal of the korean academy of Pediatric Dentistry
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• v.24 no.1
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• pp.27-40
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• 1997

This study investigated the effects of laser irradiation on the exposed pulp and the possibility of direct pulp capping with the $CO_2$ laser. Results were obtained from the observation of the residual pulpal healing process. Class V cavities on 48 anterior teeth from 8 adult dogs were prepared and pulp chambers were intentionally opened with dental explorer. The control group consisted of 16 teeth. $Dycal^{(R)}$(Caulk Co., U.S.A.) was applied to exposed site once bleeding was stopped. Cavities were sealed with $I.R.M^{(R)}$. In the experimental group 1 (16 teeth), laser(LASERSAT $CO_2^{(R)}$, Satelec Co.) was irradiated on the exposed pulp. The laser procedure followed the manufacturers recommendations for the treatment of human pulp(1.5 Watts, 0.2 seconds, unfocused), and cavities were sealed with $I.R.M^{(R)}$. In the experimental group 2 (16 teeth), laser was irradiated on the exposed pulp in a more powerful dosage(5.0 Watts, 0.2 seconds, unfocused), and cavities were sealed with $I.R.M^{(R)}$. Two dogs were sacrificed immediately after experiment and the others were sacrificed at intervals of one, three, and eight weeks respectively. All teeth were routinely processed and the pulpal tissues and odontoblastic layers were observed by the light microscope. The results were as follows; 1. In the control group, the initial mild inflammation had improved to normal by week eight. An active formation of reparative dentin was observed at week three, and at week eight, a firm dentin bridge was present beneath the $Dycal^{(R)}$ with no inflammatory responses in the remaining pulp. 2. In the experimental group 1, immediately following irradiation, the superficial shape of the exposed pulp was crater-like. And it was lined with the coagulated layer, $60{\sim}70{\mu}m$ in width. Moderate inflammatory pulpal conditions existing at week one were improved to mild at week eight. And from the week three specimens, a reparative dentin formation was observed in the adjacent odontoblastic layer of the exposed site. A dentin bridge at the exposed site, however, did not form during the experimental period. 3. In the experimental group 2, the width of the coagulation layer lining the crater was $70{\sim}130{\mu}m$. Beneath the coagulated layer, severe inflammatory pulpal responses were observed at week one, and conditions did not improve during the experimental period.

• Restorative Dentistry and Endodontics
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• v.32 no.6
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• pp.514-521
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• 2007

The purinoreceptor, $P2X_3$ is a ligand-gated cation channel activated by extracellular ATP. It has been reported that ATP can be released during inflammation and tissue damage, which in turn may activate $P2X_3$ receptors to initiate nociceptive signals. However, little is known about the contribution of $P2X_3$ to the dental pain during pulpal inflammation. Therefore, the purpose of this study was to investigate the expression of $P2X_3$ and its colocalization with TRPV1 to understand the mechanism of pain transmission through $P2X_3$ in the human dental pulp with double labeling immunofluorescence method. In the human dental pulp, intense $P2X_3$ immunoreactiyity was observed throughout the coronal and radicular pulp. Of all $P2X_3$-positive fibers examined, 79.4% coexpressed TRPV1. This result suggests that $P2X_3$ along with TRPV1 may be involved in the transmission of pain and potentiation of noxious stimuli during pulpal inflammation.

• Restorative Dentistry and Endodontics
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• v.34 no.3
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• pp.169-176
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• 2009

Diabetes Mellitus (DM) is a syndrome accompanied with the abnormal secretion or function of insulin, a hormone that plays a vital role in controlling the blood glucose level (BGL). Type land 2 DM are most common form and the prevalence of the latter is recently increasing, The aim of this article was to assess whet her Type 2 DM could act as a predisposing risk factor on the pulpo-periapical pathogenesis. Previous literature on the pathologic changes of blood vessels in DM was thoroughly reviewed. Furthermore, a histopathologic analysis of artificially-induced periapical specimens obtained from Type 2 diabetic and DM-resistant rats was compared. Histopathologic results demonstrate that the size of periapical bone destruction w as larger and the degree of pulpal inflammation was more severe in diabetic rats, indicating that Type 2 D M itself can be a predisposing risk factor that makes the host more susceptible to pulpal infection. The possible reasons may be that in diabetic state the lumen of pulpal blood vessels are thickened by atheromatous deposits, and microcirculation is hindered, The function of polymorphonuclear leukocyte is also impair ed and the migration of immune cells is blocked, leading to increased chance of pulpal infection. Also, lack of collateral circulation of pulpal blood vessels makes the pulp more susceptible to infection. These decrease the regeneration capacity of pulpal cells or tissues, delaying the healing process, Therefore, when restorative treatment is needed in Type 2 DM patients, dentists should minimize irritation to the pulpal tissue un der control of BGL.

• Restorative Dentistry and Endodontics
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• v.13 no.2
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• pp.307-322
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• 1988

The purpose of this study is to evaluate the pulpal responses to the base materials such as zinc oxide eugenol cement, calcium hydroxide, zinc phosphate cement, polycarboxylate cement and glass ionomer cement. The 100 caries free dog teeth were devided into 2 groups by remaining dentin thickness (Group A: 0.4-0.6 mm, Group B: 0.8-1.0 mm) and each group were devided into 5 subgroups. The intervals of observation period are 3days, 1 week, 2 weeks, 4 weeks and 8 weeks respectively after experiment. The specimens were fixed with 10% formalin and decalcifed in 5% nitric acid. All specimens were stained with Hematoxylin-Eosin and examined histopathologically. The results were as follows. 1. In group A, atropy or hyperplasia in odontoblasts were seen in zinc oxide eugenol cement, calcium hydroxide and zinc phosphate cement. No changes in odontoblasts were seen in polycarboxylate cement and glass ionomer cement. 2. In group A, increase of predentin were seen in all experimental materials. 3. In group A, vascular congestion were seen in all experimental materials and inflammation were seen on 3 days in zinc oxide eugenol cement, 8 weeks in zinc phosphate cement and hemorrage were seen on 3 days in zinc phosphate cement. 4. In group B, changes of odontoblasts were not seen all experimental materials. 5. In group B, increase of predentin and vascular congestion were seen in all experimental materials but inflammation were not seen.

• Restorative Dentistry and Endodontics
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• v.9 no.1
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• pp.15-24
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• 1983

Irradiation is frequently employed as the sole therapy for oral cancer. These irradiated patients presents peculiar and progressive dental problems. But there is only scanty informations concerning specific approaches to endodontic treatment for head and neck cancer patients who have been subjected to tumorcidal doses of radiation therapy. The purpose of the present study was to determine the effects of cobalt-60 radiation on the pulpal healing of dogs after the direct pulp capping. As the experimental animals, 10 dogs (above 7-8 months after birth) were divided into 3 groups (Control, Group I, Group II). The cobalt-60 was irradiated to the Group I and Group II each 1,009 and 1,562.5 rads as single dose. As the capping material Dycal$^{(R)}$(L.D. Caulk company) was selected. After the direct pulp capping the dogs were sacrified 1, 2, 3, 4, week interval and made the original slides cut with a thickness of 8 microns and stained with hematoxylin and eosin. After examination and comparision of all specimen, the results of this study were drawn as follows; 1. The formation of reparative dentin was observed from the 1st week in the Control group, the 2nd week in the Group I & II. The few and irregular tuble structure was appeared in the 4th week in the Control group only, but failed in the Group I & II. 2. The continuity of dentin bridge was appeared in the 3rd week in all group and the degeneration of odontoblast in the 1st week of the Group II. 3. The congestion and hemorrhage in the pulp tissue were observed in all groups until 3rd week. The inflammation was appeared within the 2nd week in the Group I and especially marked in the Group II, but absent in the Control group. 4. In cases Dycal into the pulp tissue deeply, the local necrosis of pulp and decrease of dentin formation was observed.