• Restorative Dentistry and Endodontics
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• 제14권1호
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• pp.109-118
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• 1989

The purpose of this study was to investigate the bio-stimulating effect of low power density laser radiation on the mechanically exposed pulp. Class V cavities on dog's teeth were prepared and the pulps were mechanically exposed with a round bur. In control group, the exposed pulps were capped with $Ca(OH)_2$ powder and the cavities were sealed with Z.O.E.. In experimental group A, the pulps were irradiated with GaA1As laser for 5 minutes and then they were treated the same as control group. In experimental group B, the exposed pulps were covered by aluminum foil and sealed with Z.O.E. after they were irradiated with the laser as the experimental group A. In the all groups, the pulps were histopathologically observed at the time intervals of 1, 2 and 3 week after experiment and the results were statistically evaluated. The results were as follows: 1) In control and experimental groups, mild vascular congestion and bleeding was found in most of the specimens and for the new formation of dentin bridge, experimental group A had the most cases. The dentin bridge had discontinuous osteodentin like appearance without any dentinal tubules. Inflammatory cell infiltration consisted of acute and chronic inflammatory cell, and the formation of microabscess was also observed. 2) The degree of inflammatory cell infiltration was not significantly different among control group and experimental groups at 1 week, 2 week and 3 week. 3) The formation of new dentin bridge was not significantly different between control group and experimental group A at 1 week, but at 2 week and 3 week, experimental group A showed significantly more cases of new dentin formation than control groups. (P < 0.05). 4) Between control group and experimental group B, there was no significant difference in formation of the new dentin bridge at 1, 2 and 3 week. (P> 0.05). 5) There was no significant difference in formation of the new dentin bridge at 1 and 2 week between experimental group A and experimental group B, but at 3 week, the former significantly had more cases of new dentin bridge formation than the latter.(P < 0.05).

• Restorative Dentistry and Endodontics
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• 제14권2호
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• pp.77-97
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• 1989

The purpose of this study was to observe the effect of ${\beta}GP$ in the remaining dental pulp tissue after pulpotomy in the dogs' teeth. For vital pulpotomy, 72 dogs' teeth were used and class V cavities were prepared and the pulps were amputated. ZOE and Dycal (Caulk Co., USA) were placed over the amputated tissue and cavities were sealed with ZOE cement in the control group. In the experimental group, ${\beta}GP$, ${\beta}GP$-ZOE, ${\beta}GP$-Dycal were placed over the exposed pulp tissues respectively. Dogs were sacrificed after 1, 2 and 4 weeks following the operations and the teeth were decalcified in the nitric acid, sectioned and stained with HE for light microscopic examination. For electron microscopic examination, specimens were made after 2 and 4 weeks following the operation. A comparative microscopic examination revealed as follows. 1. The dentin bridge was formed continuously due to osteodentin in the ${\beta}GP$-Dycal group at the 2nd week, the dentin bridge composed of osteodentin and tubular dentin was observed at the 4th week. 2. Osteodentin formation was vigorously in the ${\beta}GP$-Dycal than in the Dycal group. 3. In the surface of osteodentin the osteodentinoblasts showing vivid synthetic activity were observed and the matrix vesicles were presented during calcification of osteoid dentin matrix. 4. The dentin bridge formation was not observed in ${\beta}GP$ group and ${\beta}GP$-ZOE group.

• Restorative Dentistry and Endodontics
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• 제22권2호
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• pp.710-719
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• 1997

Aucubin, an iridoid glucoside, which is isolated from Aucuba japonica, has some biological effects. This study was to investigate the effect of aucubin on the remainig pulp tissues after pulpotomy. Mongrel dog's coronal pulps were mechanically exposed with a sterile round bur and excised with sterile sharp excarvator. After bleeding was controlled, in control group, $Ca(OH)_2$ powder was applied on the remaining pulps and the cavities were sealed with Z.O.E. cement. In experimental group 1, mixed powder with $Ca(OH)_2$ and aucubin(l : 1 by weight) was applied on the pulpotomized pulp surfaces. After the cavities were covered with sterile aluminum foil, they were sealed with Z.O.E. cement. In experimental group 2, only aucubin powder was applied on the remaining pulps and then they were treated the same as experimental group 1. In the all groups, the pulps were histopathologically observed by light microscope at the time intervals of 1, 2 and 4 weeks after experiment. The results were as follows : 1. In control and experimental groups, mild vascular congestion and bleeding were found in most of the specimens. Less inflammatory infiltration was observed in experimental groups than in control group. 2. Dentin bridge formation was found after 1 week at both control and experimental group 1. Dentin birdge had discontinuous osteodentin like appearance or contained some dentin chips. In experimental group 2, dentin bridge was not seen. 3. The coagulation necrosis layer on the remaining pulp tissues was seen in all groups. In experimental group 2, the thickest layer was observed. And in control group, coagulation necrosis layer was similar as in experimental group 1.

• Restorative Dentistry and Endodontics
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• 제22권2호
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• pp.720-730
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• 1997

This study was performed to observe the histopathological response to the bonding resin directly applied on the remaining pulp tissues. 40 teeth from 3 adult dogs were pulpotomized with a sterile round bur and sharp excarvater. In the control group, $Ca(OH)_2$ powder was applied on the pulp tissue and the cavities were sealed with IRM cement. In the experimental group 1, Superbond C&B was applied on the remaining pulp and the cavities conditioned with 10-3 solution were filled with the mixture of the MMA liquid, PMMA powder and Catalyst. Multi-purpose adhesive was used on the remaining pulp tissue in the experimental group 2 and Z-100 was filled in the cavities. In the experimental group 3, Clearfil photobond applied and directly photo-cured on the pulp tissue, then the cavities were treated with CA agent (10% citric acid and 20% $CaCl_2$ aqueous solution) for 20 seconds, washed and applied with Clearfil photobond then filled with Protect liner. The experimental animals were sacrified at the 1st, 2nd, and 4th week. The specimens were routinely processed and stained with H-E for light microscopic observation. The results were as followed : 1. In the experimental group 1, the number and characteristics of the dentin bridge formation case was similar to those in the control group and less cases were observed in the experimental group 2 and 3 than experimental group 3. The inflammatory response in experimental group 1 was less than that in the control group at 1st week but there had been little difference at between 2nd and 4th week. 2. The number of the dentin bridge in experimental group 2 was less than that in control group and experimental group 1. The inflammatory response of the experimental group 1 was similar to that of experimental group 1 but less than that of the control group. A number of bleeding and vascular congestion were observed. The least inflammatory response was seen in the experimental group 2 among all groups. 3. In the experimental group 3, one case of the dentin bridge formation was observed and that was the same as that in the experimental group 2 but smaller than that of the control and experimental group 1. The inflammatory response of the experimental group 3 was least at the 1st week and most at the 4th week in the all group.

• Restorative Dentistry and Endodontics
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• 제24권4호
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• pp.554-559
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• 1999

Aucubin, an iridoid glucoside isolated from Aucuba japonica, has pharmacological effects such as antimicrobial effect, liver protective function and inhibition of liver RNA and protein biosynthesis, etc. This study was performed to observe the effect of aucubin on the pulp tissue after pulpotomy. Aucubin was converted to aucubinogenin as an active form by ${\beta}$-glucosidase. In 3 Mongrel dogs, the pulps were mechanically exposed with a sterile round bur and excised with sterile excavator. After bleeding control, aucubin was applied on remaining pulp tissues and then they were sealed with IRM in experimental group. In control group, $Ca(OH)_2$ powder was applied on remaining pulp tissues and then they were sealed with IRM. After interval of 1 and 12 weeks, the dogs were sacrificed. The teeth were prepared for histologic evaluation and examined by light microscope. Aucubin 1 week group showed that mild inflammation and vascular congestion in most of the specimen. More various degree of inflammation was found in experimental group than in control group. Premature calcified mass were found in the both 1 weeks groups. Continuous well-formed dentin bridge was found in both 12 weeks groups. Collectively, this study suggests that the possibility of aucubin as a medicament after pulpotomy.

• 대한소아치과학회지
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• 제8권1호
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• pp.37-46
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• 1981

This study was undertaken to evaluate the pulpal responses to the pulp-capping materials such as glutaraldehyde and formocresol in pulpotomy technique, especially in the primary dentition. Mandibular primary canines and molars of 5 dogs (aged about 8-9 weeks)were selected for this study. The intervals of observation for histologic study of pulpotomized primary teeth with 2% glutaraldehyde, formocresol and calcium hydroxide in the usual manner ranged from 2 hours, 1 week, 2 weeks, 3 weeks and 5 weeks after experiments respectively. Each specimens were fixed with 10% formalin and decalcified in 5% nitric acid. All slides were stained with Hematorylin-Eosin and examined histopathologically. The results were as follows; 1. In calcium hydroxide groups, formation of dentin bridge was initiated in 1 week after experiments and completed in 5 weeks after experiments. 2. Formation of dentin bridge was not seen, whereas necrosis of pulp tissue was noted, in formocresol and glutaraldehyde groups. 3. Duration of tissue reactions and tissue changes were similar, in formocresol and glutaraldehyde groups. 4. In formocresol and glutaraldehyde groups, amputation surfaces of the pulp were covered with blood clots, beneath which coagulation necrois was noted, but inflammatory cells were not prominent, in 2 hours and 1 week after experiments. But coagulation necrosis was proceeded to the apical portion, accompanied by infiltration of inflammatory cells, since 2 weeks after experiments. And suppuration or gangrene of the pulp tissue were noted in 3 weeks and 5 weeks groups. 5. Suppuration or gangrene of pulp seemed to provoke the resorption of dentin wall, and inflammatory changes and resorption of roots were noted in the periodontal membrane near the periapical region. 6. As compared with calcium hydroxide groups, resorption of the root was pronounced in form or cresol and glutaraldehyde groups. Effects of medicaments to the succedaneous tooth germ were not seen.

• Restorative Dentistry and Endodontics
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• 제46권2호
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• pp.17.1-17.9
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• 2021

Objectives: In recent in vitro study, it was reported that osteostatin (OST) has an odontogenic effect and synergistic effect with mineral trioxide aggregate (MTA) in human dental pulp cells. Therefore, the aim of this study was to evaluate whether OST has a synergistic effect with MTA on hard tissue formation in vivo. Materials and Methods: Thirty-two maxillary molars of Spraque-Dawley rats were used in this study. An occlusal cavity was prepared and the exposed pulps were randomly divided into 3 groups: group 1 (control; ProRoot MTA), group 2 (OST 100 μM + ProRoot MTA), group 3 (OST 10 mM + ProRoot MTA). Exposed pulps were capped with each material and cavities were restored with resin modified glass ionomer. The animals were sacrificed after 4 weeks. All harvested teeth were scanned with micro-computed tomography (CT). The samples were prepared and hard tissue formation was evaluated histologically. For immunohistochemical analysis, the specimens were sectioned and incubated with primary antibodies against dentin sialoprotein (DSP). Results: In the micro-CT analysis, it is revealed that OST with ProRoot MTA groups showed more mineralized bridge than the control (p < 0.05). In the H&E staining, it is showed that more quantity of the mineralized dentin bridge was formed in the OST with ProRoot MTA group compared to the control (p < 0.05). In all groups, DSP was expressed in newly formed reparative dentin area. Conclusions: OST can be a supplementary pulp capping material when used with MTA to make synergistic effect in hard tissue formation.

• The Journal of Advanced Prosthodontics
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• 제8권3호
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• pp.224-228
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• 2016

PURPOSE. This study aimed to investigate whether dentin surface preparation with diamond rotary instruments of different grit sizes affects the shear bond strength of resin-bonded restorations. MATERIALS AND METHODS. The buccal enamel of 60 maxillary central incisors was removed with a low speed diamond saw and wet ground with silicon carbide papers. The polished surfaces of the teeth were prepared with four groups of rotary diamond burs with super-coarse (SC), coarse (C), medium (M), and fine (F) grit sizes. Following surface preparation, 60 restorations were casted with nickel-chromium alloy and bonded with Panavia cement. To assess the shear bond strength, the samples were mounted on a universal testing machine and an axial load was applied along the cement-restoration interface at the crosshead speed of 0.5 mm/min. The acquired data was analyzed with one way ANOVA and Tukey post hoc test (${\alpha}=.05$). RESULTS. The $mean{\pm}SD$ shear bond strengths (in MPa) of the study groups were $17.75{\pm}1.41$ for SC, $13.82{\pm}1.13$ for C, $10.40{\pm}1.45$ for M, and $7.13{\pm}1.18$ for F. Statistical analysis revealed the significant difference among the study groups such that the value for group SC was significantly higher than that for group F (P<.001). CONCLUSION. Dentin surface roughness created by diamond burs of different grit sizes considerably influences the shear bond strength of resin bonded restorations.

• Restorative Dentistry and Endodontics
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• 제41권1호
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• pp.29-36
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• 2016

Objectives: The purpose of this study was to assess the ability of two new calcium silicate-based pulp-capping materials (Biodentine and BioAggregate) to induce healing in a rat pulp injury model and to compare them with mineral trioxide aggregate (MTA). Materials and Methods: Eighteen rats were anesthetized, cavities were prepared and the pulp was capped with either of ProRoot MTA, Biodentine, or BioAggregate. The specimens were scanned using a high-resolution micro-computed tomography (micro-CT) system and were prepared and evaluated histologically and immunohistochemically using dentin sialoprotein (DSP). Results: On micro-CT analysis, the ProRoot MTA and Biodentine groups showed significantly thicker hard tissue formation (p < 0.05). On H&E staining, ProRoot MTA showed complete dentin bridge formation with normal pulpal histology. In the Biodentine and BioAggregate groups, a thick, homogeneous hard tissue barrier was observed. The ProRoot MTA specimens showed strong immunopositive reaction for DSP. Conclusions: Our results suggest that calcium silicate-based pulp-capping materials induce favorable effects on reparative processes during vital pulp therapy and that both Biodentine and BioAggregate could be considered as alternatives to ProRoot MTA.

• 대한소아치과학회지
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• 제24권1호
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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.