• Restorative Dentistry and Endodontics
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• 제20권2호
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• pp.744-757
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• 1995

Implantation of demineralized bone matrices was done into the amputated pulp in vivo and sequential reaction of the pulpal ectomesenchymal cells was observed. The bone matrices, obtained from cat long bone were crushed into below $700{\mu}m$, demineralized with 0.5N HCl and allografted into pulp of molar teeth. At seven days after implantation many undifferentiated mesenchymal cells aggregated near the matrices in the pulpal tissue. At fourteen days after implantation, the cells differentiated into preosteoblast-like cells which have secretory cell characteristics. At one or two months after implantation osteoid tissue was formed. The cells, which are located at the surface of the tissue, contained abundant dilated rough endoplasmic reticulum, Golgi apparatus and secretory granules in the cytoplasm. The matrix of the tissue has less collagen fibers than those in normal dentin. These results suggest that the interaction of pulpal mesenchymal cells with demineralized bone matrix can be a model which induces mineralization.

• 대한소아치과학회지
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• 제23권3호
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• pp.631-639
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• 1996

Electrosurgical technique have been used in dentistry as an aid to soft tissue management for nearly 60 years. However, it was not until the late 1960s that the principles of electrosurgery were understood and improved equipment became available. Electrosurgery is a surgical procedure performed on soft tissue utilizing controlled high frequency electricaI(radio-frequency) currents in the range of 1,500,000 to 7,500,000 cyclesper second. The radio-frequency energy used in electrosurgery is able to cut and coagulate tissue because it focuses the energy at the small, active electrode. Advantages of electrosurgery for soft-tissue management during dental procedures include improved hemostasis, ease of tissue modification, improved visibility and so on, but adverse healing responses-including necrosis of soft tissue and sequestration of alveolar bone-have been reported. The present report provides examples of treatment of soft tissue and pulp tissue of primary teeth by electrosurgery. The results are as follows; 1. Electrosurgical techniques can be used for various procedures in pedodontics. 2. Electrosurgical procedures provide improved hemostasis and visibility in the operating field, which enable to remove, reshape, and contour soft tissues easily. 3. In pulpotomy technique, it was difficult to expect the variable pulpal response based on the degree of heat accumulation and the conditions of pulp tissues. Therefore, electrosurgical pulpotomy could not be considered as a method superior to formocresol pulpotomy. 4. A greater degree of dexterity and experiences in manipulation of the electrode is required compared with the conventional scalpel surgery.

• Restorative Dentistry and Endodontics
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• 제9권1호
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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.

• Restorative Dentistry and Endodontics
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• 제14권1호
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• pp.71-84
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• 1989

The purpose of this study was to evaluate the effect of tricalcium phosphate and Vitapex on the dogs' periapical tissues. Twenty mandibular premolars from 5 healthy dogs were used for this study. After the animals were anesthetized intramuscularly, pulp chambers were open and pulp tissue was extirpated with a barbed broach and H-file. Then the working length of the root canal was measured with H-file and pulp tissue was completely removed. Before the actual canal filling, the root canals of twenty teeth have been experimentally infected with opening the pulp chamber for 5 weeks. Periapical radiographs of the experimental teeth were taken to monitor the periapical pathological condition. Each root apex of 20 premolars was perforated with engine reamer and the root canals were enlarged with No. 30-60 H-files. They were divided into treated as follows. Control group: The root canal was filled with gutta-percha. Experimental group 1: The canal was dried with sterile paper points and mixture of tricalcium phosphate and physiological saline was overfilled beyond the root apex with a lentulo spiral. Then the root canal was filled gutta-percha and lateral condensation and the pulp chamber was filled with Caviton. Experimental group 2: The root canals were overfilled with Vitapex and were treated in the same manner as those in experimental group 1 At 1,2,3, and 8 weeks after experiment, the periapical tissues including the alveolar bone were fixed with 10% formalin solution for I week and decalcified with Plank-Rycho solution for 5 weeks. The specimens were embedded in paraffin and serial sections were cut into a thickness of 6 ${\mu}m$ at the plane of the root apex. Hematoxyline-eosin and Masson's trichrome stain were made for the histo-pathological examinations. The results were as follows: 1. Ingrowth of collagen fiber was observed from 1 week in control group and experimental groups. 2. The rate of bone formation of experimental group 1 was accelerated more than that of experimental group 2. 3. Resorption of cementum was seen in control group, but apposition of cementum was seen in experimental groups.

• 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.

• Restorative Dentistry and Endodontics
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• 제48권2호
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• pp.12.1-12.11
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• 2023

Objectives: The present study evaluated the pulp response of human mandibular incisors subjected to in-office dental bleaching using gels with medium or high concentrations of hydrogen peroxide (HP). Materials and Methods: The following groups were compared: 35% HP (HP35; n = 5) or 20% HP (HP20; n = 4). In the control group (CONT; n = 2), no dental bleaching was performed. The color change (CC) was registered at baseline and after 2 days using the Vita Classical shade guide. Tooth sensitivity (TS) was also recorded for 2 days post-bleaching. The teeth were extracted 2 days after the clinical procedure and subjected to histological analysis. The CC and overall scores for histological evaluation were evaluated by the Kruskal-Wallis and Mann-Whitney tests. The percentage of patients with TS was evaluated by the Fisher exact test (α = 0.05). Results: The CC and TS of the HP35 group were significantly higher than those of the CONT group (p < 0.05) and the HP20 group showed an intermediate response, without significant differences from either the HP35 or CONT group (p > 0.05). In both experimental groups, the coronal pulp tissue exhibited partial necrosis associated with tertiary dentin deposition. Overall, the subjacent pulp tissue exhibited a mild inflammatory response. Conclusions: In-office bleaching therapies using bleaching gels with 20% or 35% HP caused similar pulp damage to the mandibular incisors, characterized by partial necrosis, tertiary dentin deposition, and mild inflammation.

• 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)

• 대한소아치과학회지
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• 제27권2호
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• pp.318-332
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• 2000

탈회냉동건조골과 교원질을 치수치료제로서 이용할 수 있는지의 여부를 규명하기 위하여, 성견의 치아를 대상으로 치수절단술을 시행하여 치수조직의 염증반응, 재생성 상아질의 형성 등 치수조직반응을 평가하기 위하여 시행되었다. 체중 10kg 내외의 4마리의 성견 치아에 소독된 round bur을 이용하여 5급 와동을 형성한 후 치수절단술을 시행하였다. 대조군으로는 수산화칼슘으로 치수 복조을 시행하고 IRM으로 밀봉하였으며, 실험군으로는 교원질과 탈회냉동건조골을 이용하여 복조한 후 대조군에서와 같은 방법으로 밀봉하였다. 실험동물은 3일, 1주일, 2주일, 4주일 경과 후 관류 고정으로 희생되었으며, 조직표본을 제작한 후 광학현미경과 투과전자현미경으로 치수 조직 반응을 관찰 평가한 결과 다음과 같은 결론을 얻었다. 1. 모든 군에서 치수괴사 소견은 보이지 않았으며, 대조군과 실험 2군에서는 1주일 후부터 염증이 소실되었으나, 실험 1군에서는 2주까지 염증소견을 보이며 절단된 치수 측벽의 조상아세포들도 배열이 불규칙하였다. 2. 대조군에서는 2주부터 불완전한 상아질교가, 4주 경과 후에는 골양상아질과 완전한 상아질교가 관찰되었으며, 1군에서는 섬유성피막은 형성되었으나 조상아세포와 상아질교의 형성소견은 관찰되지 않았다. 2군의 경우 2주 경과 후 탈회냉동건조골 주위에 분화된 조상아세포들에 의해 형성된 상아전질과 재생성 상아질이 관찰되었으나 상아질교의 형성소견은 관찰되지 않았다. 3. 대조군과 2주군에서 1주일 경과 후에 크고 호염기성 핵을 갖는 세포들이 치수절단부 하방과 탈회냉동건조골 주위에 모여드는 양상을 보였는데, 이와 같은 현상은 대조군에 비해 2군에서 더욱 현저하였으며 시간이 경과될수록 규칙적으로 배열한 조상아세포와 재생성 상아질을 관찰할 수 있었다. 4. 대조군과 2군에서 조상아세포는 극성을 띤 핵, 조면내형질세망, 골지체, 분비과립 등을 포함하는 세포질과 유기기질을 분비하는 소견 등, 석회화가 이루어지는 초미세구조를 보였다. 이상의 결과를 종합하면 탈회냉동건조골은 치수의 미분화 간엽세포로부터 조상아세포의 분화를 유도하여 치수절단부위에 재생 상아질을 형성할 수 있는 것으로 사료된다.

• 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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• 제28권5호
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• pp.419-424
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• 2003

이 연구의 목적은 원래의 치수조직과 유사한 조직을 재생하기 위한 pulp tissue engineering의 한 방법으로 건전한 조직으로부터 배양된 치수세포와 쥐의 조섬유세포(NIH 3T3 cell)를 Rat tail type I collagen solution에서 3차원적으로 관찰하기 위한 것으로, 콜라젠 젤의 수축량과 세포의 증식 량을 비교하였으며, 또한 마모된 사람치아의 표면과 배양용기에서 두 세포의 증식 량을 비교하여 다음과 같은 결과를 얻었다. 1. 콜라젠 젤에 NIH 3T3 세포를 배양한 경우 그 수축량은 최소였으나, 치수세포를 배양한 경우 그 수축량은 현저하였다. 2. 서로 다른 수의 치수세포를 콜라젠 젤에서 배양시킨 경우 세포 수가 많을수록 수축량이 증가하였으며, 세포가 없는 콜라젠 젤은 수축하지 않았다. 3. 치수세포를 콜라젠 젤에서 18일간 배양시킨 후 세포의 증식은 거의 없는 반면, NIH 3T3 세포는 계속 증식하였다. 4. 마모된 사람 치아 표면과 배양 용기에서 치수세포와 NIH 3T3세포를 배양한 경우 NIH 3T3세포가 치수세포에 비해 빠르게 증식 하였으며 , 특히 사람 치아의 표면에서 NIH 3T3세포가 현저히 빠른 증식을 보였다. 이상의 결과는 치수세포를 type I collagen gel에서 3차원 적으로 배양 후 치수조직의 재생을 유도하는 pulp tissue engineering에 관한 연구에 발판이 될 것으로 사료된다.