• Restorative Dentistry and Endodontics
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• v.35 no.1
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• pp.5-12
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• 2010

The purpose of this study was to evaluate the pulp tissue reaction to direct pulp capping of mechanically exposed beagle dogs' pulp with several capping materials. A total of 36 teeth of 2 healthy beagle dongs were used. The mechanically exposed pulps were capped with one of the followings: (1) Mineral Trioxide Aggregate (MTA: $ProRoot^{(R)}$ MTA. Dentsply, Tulsa, USA), (2) Clearfil SE Bond (Dentin adhesive system: Kuraray, Osaka, Japan), (3) Ultra-Blend (Photo-polymerized Calcium hydroxide: Ultradent, South Jordan, USA), (4) Dycal (Quick setting Calcium hydroxide: LD Caulk Co., Milford, USA) at 7, 30, and 90 days before sacrificing. The cavities were restored with Z350 flowable composite resin (3M ESPE, St. Paul. MN, USA). After the beagle dogs were sacrificed, the extracted teeth were fixed, decalcified, prepared for histological examination and stained with HE stain. The pulpal tissue responses to direct pulp capping materials were assessed. In MTA calcium hydroxide, and photo-polymerized calcium hydroxide groups, initial mild inflammatory cell infiltration, newly formed odontoblast-like cell layer and hard tissue bridge formation were observed. Compared with dentin adhesive system, these materials were biocompatible and good for pulp tissue regeneration. In dentin adhesive system group, severe inflammatory cell infiltration, pulp tissue degeneration and pulp tissue necrosis were observed. It seemed evident that application of dentin adhesive system in direct pulp capping of beagle dog teeth cannot lead to acceptable repair of the pulp tissue with dentine bridge formation.

• Journal of the korean academy of Pediatric Dentistry
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• v.27 no.2
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• pp.318-332
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• 2000

The purpose of this study was to investigate the effects of demineralized freeze-dried bone (DFDB) on mechanically exposed pulp of dog by evaluating the pulpal inflammation and healing process, formation of dental hard tissue, and structural changes of fibroblasts of the remaining pulp tissue. Teeth of 4 dogs, weighing 10kg, were used in this study. Class V cavities were prepared followed by exposed the pulp tissue mechanically by sterilized round bur. In control group, exposed pulps were capped with calcium hydroxide paste followed by sealed with IRM. In experimental groups, the exposed pulps of one group were capped with the collagen and those of the other group were capped with DFDB. All cavities were sealed with same manor as control group. The animals were sacrificed at the intervals of 3, 7, 14, and 28 days for histopathlogic evaluation. The specimens were observed by the light microscope and trans-electron microscope. The results were as follows: 1. Pulp necrosis was not observed in all groups. Inflammatory response was disappeared from 1 week in control group and group 2. But it was not disappeared until 2 weeks and also irregular arrangement of odontoblasts was showed at the lateral walls of root canal just beneath the amputated site of the pulp in group 1. 2. Dentinal bridge was formed incompletely at 2 weeks but it was formed completely at 4 weeks in control group. Odontoid tissue was also found in control group at 4 weeks from treatment. Amputated site of pulp was encapsulated with fibrous tissue and odontoblast and dentinal bridge was not found in group 1. Preodontoid tissue and reparative dentin which were formed by odontoblast differentiated around DFDB were found, but dentinal bridge was not found in group 2. 3. Cell with large basophillic-stained nuclei infiltrated to amputated site and DFDB at 1 week from treatment in control group and group 2. They were found more in group 2 than in control group. Odontoblasts arranged more regularly and reparative dentin was found more as time elapsed. 4. Dentin-formative odontoblasts which showed ultramicrostructure of cytoplasm with polarized nucleus, rEM, Golgi complex, secretory granules, secretion of organic matrix in control of group and group 2. In regards to above results, the demineralized freeze-dried bone(DFDB) induce odontoblastic differentiation and further come up to the dentin formation in amputated pulp.

• Restorative Dentistry and Endodontics
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• v.8 no.1
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• pp.123-131
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• 1982

The purpose of this study was to observe the responses of the remaining pulp tissue after pulpotomy upon the several kinds of $Ca(OH)_2$ products and the responses of periapical tissue upon some root canal filling materials after extirpation. For pulpotomy, the class V cavities were prepared on the premolars, molars and upper canines, and the pulp was amputated. Each drug was placed over the amputated tissue and cavity was sealed with zinc oxide eugenol cement. The drugs which were used for the study were Dycal (Caulk Co. U.S.A.), Cavitec (Kerr Co. U.S.A.), Calvital, Nobudyne and Neodyne (Neo Dental Chemical Products). For extirpation, the endodontic cavities were prepared on the lingual surfaces of anterior teeth, and the pulp tissues were extirpated as routine method. After enlarging, irrigation, and measuring of root length by taking X-ray, each root canal filling material was filled in the canal with gutta percha cone, and endodontic cavity was sealed with zinc oxide eugenol cement. Zinc oxide eugenol, $Ca(OH)_2$ (Eli Lilly Co. U.S.A.) and Vitapex (Neo Dental Chemical Products) were used as root canal filling materials. Animals were sacrificed after 1, 3 and 6 weeks following the operation. The teeth were decalcified in formic acid, sectioned and stained with hematoxylin eosin. Microscopic examination revealed as follows. 1. Dycal: The dentin bridge formation was observed at the 3rd week after pulpotomy. Inflammatory conditions which were infiltration of inflammatory cells and dilatation of blood vessels were kept in remaining pulp tissue at the 6th week. 2. Calvital: The dentin bridge was observed at the 1st week after pulpotomy. As the time clasped, the pulp tended to be the fibrous degeneration. 3. Cavitec, Nobudyne and Neodyne: In the case of Cavitec and Nobudyne, the incompleted and irregular dentin bridge was observed at the 6th week, and in Neodyne, was observed at the 3rd week. The severe inflammatory changes were seen in the remaining pulp tissue. As the time clasped, the fibrous degeneration tended to spread in the remaining pulp tissue. 4. $Ca(OH)_2$: Osteocementum was formed at the 3rd week, the matrix of cementum and dentin were resorted, and infiltration of lymphocytes was seen in periapical tissue when $Ca(OH)_2$ was used as canal-filling materials. S. ZOE and Vitapex The cementum like substance was seen in periapical portion at the 1st week, when ZOE and Vitapex were used as root canal filling materials. As the time elapsed, the matrix of cementum and dentin tended to be resorted. At the 6th week, the inflammatory condition of periapical tissue was continued in the case of ZOE, but was reduced in the case of Vitapex.

• Journal of Yeungnam Medical Science
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• v.37 no.3
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• pp.217-225
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• 2020

Background: This study was performed to provide a long-term bacterial seal through the formation of reparative dentin bridge, calcium silicate-based pulp capping materials have been used at sites of pulpal exposure. The aim of this study was to evaluate the mineralization-inducing potentials of calcium silicate-based pulp capping materials (ProRoot MTA [PR], Biodentine [BD], and TheraCal LC [TC]) in human dental pulp cells (HDPCs). Methods: Specimens of test materials were placed in deionized water for various incubation times to measure the pH variation and the concentration of calcium released. The morphology of HDPCs cultured on the specimens was examined using a confocal laser scanning microscope (CLSM). Alizarin red S staining and alkaline phosphatase assays were used to evaluate mineralization-inducing potentials of the capping materials. Results: BD showed the highest calcium release in all test periods, followed by PR and TC. (p<0.05). All experimental groups showed high alkalinity after 1 day, except at 14 days. BD showed the highest cell viability compared with PR and TC after 1 and 3 days, while TC showed the lowest value (p<0.05). The CLSM analysis showed that cells were well adhered and expressed actin filaments for all pulp capping materials. Mineralization by PR and BD groups was higher than that by TC group based on alizarin red S staining. BD showed significantly higher alkaline phosphatase activity than PR and TC, while TC showed the lowest value (p<0.05). Conclusion: Within the limitations of the in vitro study, BD had higher mineralization-inducing potential than PR and TC.

• 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.

• Journal of the korean academy of Pediatric Dentistry
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• v.26 no.4
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• pp.616-622
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• 1999

The primary objective of pulp treatment is to maintain the integrity and health of the oral tissues. The most important and difficult aspect of pulp therapy is determining the health of the pulp, or its stage of inflammation, so that a decision can be made regarding the best form of treatment. Immature permanent teeth are good candidates for many pulp healing procedures, due to their rich blood supply, which is believed to enhance the pulp's ability to react successfully to various insults. Healing was considered to have taken place when the tooth fulfilled the following criteria: 1. Abscence of clinical symtoms 2. Radiographic evidence of dentin bridge formation 3. No intrapulpal or periapical pathosis was evident radiographically 4. Continued root development and closure of the apex in immature teeth 5. Normal dentin apposition in mature teeth 6. Positive response to electrical pulp test This presents a report of cases in which immature permanent teeth, pulp-exposed by caries or trauma, was treated successfully by partial pulpotomy.

• Restorative Dentistry and Endodontics
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• v.20 no.2
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• pp.399-422
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• 1995

The purpose of this study was to investigate a fragment of possibility of pulpotomy with the Nd-YAG laser by the observation of pulpal healing process and the fine structural changes of the fibroblasts of the remaining pulpal tissues. Class V cavities on !55 teeth from 4 adult dogs were prepared and the pulp chambers were opened with a sterilized round bur. In the control group(19 teeth), the exposed coronal pulps were excised by a sharp excarvator. After bleeding was controlled with the sterilized cotton pellets, calcium hydroxide powder was applied on the remaining pulpal tissues and the cavities were sealed with Z.O.E. In the experimental group 1 : the pulpotomy with laser-calcium hydroxide powder application group(l9 teeth), the exposed coronal pulps were excised by Nd-YAG laser(10 watts power, 2 psi water, 20 psi air) for 2 or 3 seconds and calcium hydroxide powder was applied on the remaining pulpal tissues and the cavities were sealed with Z.O.E. In the experimental group 2 : the pulpotomy with laser-no calcium hydroxide powder application group(17 teeth), after amputating the coronal pulps with Nd-YAG laser as the experimental group 1, the remaining pulpal tissues were covered with stenilized aluminum foil and the cavities were filled with Z.O.E. The animals were sacrificed at the intervals of 1, 2, 3 and 4 weeks. All the teeth were rouutinely processed and the remaining pulpal tissues were observed by the light microscope and electron microscope. The results were as follows : 1. In light microscopic findings, there was no significant difference of the inflammatory response in the remaining pulpal tissues between the control group and the experimental groups. In both of the experimental group 1 : pulpotomy with laser-calcium hydroxide powder application group and the control group, the dentin bridges were observed after 2 weeks and the structure of the dentin bridge was almost same. In the experimental group 2 : pulpotomy with laser-no calcium hydroxide powder application group, the fibrous layers instead of dentin bridge were observed on the superficial portion of the remaining pulpal tissues after 2 weeks and they were consisted with densely crowded active fibroblasts. 2. In the electronmicroscopic findings, the active fibroblasts in the experimental groups were more frequently observed than in the control group at 1 week. But active fibroblasts were found with same frequency after 2 weeks in all of the control group and the experimental groups. 3. General distortions of the cell such as loss of the cell membrane, vaculoization of the cell etc. were observed at the suberficial layer of the remaining pulpal tissues and the carbonization was found in the dentinal wall in 1 week of the experimental groups. 4. In the experimental group 2 : pulpotomy with laser-no calcium hydroxide powder application group, the activity and the density of the fibroblasts in the fibrous layer were more than those in the deep portion of the remaining pulpal tissues after 2 weeks. 5. In the control group, bacteria such as cocci and bacilli were observed frequently, but in the experimntal groups, they could not be observed.

• Restorative Dentistry and Endodontics
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• v.9 no.1
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• pp.7-14
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• 1983

The purpose of this study was to investigate pulpal responses to tricalcium phosphate and durapatite which recently introduced as a bone substitute. Tricalcium phosphate and durapatite were placed on the amputated pulp tissue in the dog's teeth. Animals were sacrificed after 1, 2, 3 and 4 weeks and specimens were decalcified, embedding, sectioned and stained routinly. Microscopic examination reveals as follows; 1. Tricalcium phosphate: Severe inflammatory change was seen in the all cases and calcified masses were seen at 2 weeks. Calcified masses were enlarged according to the time elapsed. 2. Durapatite: Severe inflammatory change and pus cavities were found at 1 week. There was no evidence of healthy cell component in the remaining pulp tissue and degenerative change was obvious at 2, 3 and 4 weeks. 3. Dentin bridge was not formed in the both cases. In the case of tricalcium phosphate osteoblasts were observed unevenly around the calcified masses which were composed of hematophilic substance in central portion and eosinophilic substance in peripheral region of the masses.

• Restorative Dentistry and Endodontics
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• v.6 no.1
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• pp.17-25
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• 1980

The purpose of this study was to evaluate the pulpal response against calcium hydroxide and zinc oxide containing various concentration of formocresol (0.1, 0.5, 1, 5, 10, 20 and 30%). The experiment was performed on dog's teeth (75 teeth from 5 dogs: Table 1.) and the teeth were routinly treated in laboratory procedures. Followings are the results obtained through microscopical examination. 1. In zinc oxide group, intlammatory reaction was severe in low concentrated formocresol and the (higher the concentration of formocresol the milder the inflammatory reaction was more evident. 2. In zinc oxide group, inflammatory change was milder at 3 weeks than 1 week, and proliferation of young connective tissue was seen at 3 weeks. 3. In calcium hydroxide group, inflammatory change in relation to the concentration of formocresol was not noticeable. 4. In calcium hydroxide group, repair process with decreased inflammatory reaction and fibrosis, and dentin bridge like layer was found at 3 weeks.

• Restorative Dentistry and Endodontics
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• v.38 no.4
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• pp.258-262
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• 2013

The restorative management of deep carious lesions and the preservation of pulp vitality of immature teeth present real challenges for dental practitioners. New tricalcium silicate cements are of interest in the treatment of such cases. This case describes the immediate management and the follow-up of an extensive carious lesion on an immature second right mandibular premolar. Following anesthesia and rubber dam isolation, the carious lesion was removed and a partial pulpotomy was performed. After obtaining hemostasis, the exposed pulp was covered with a tricalcium silicate cement (Biodentine, Septodont) and a glass ionomer cement (Fuji IX extra, GC Corp.) restoration was placed over the tricalcium silicate cement. A review appointment was arranged after seven days, where the tooth was asymptomatic with the patient reporting no pain during the intervening period. At both 3 and 6 mon follow up, it was noted that the tooth was vital, with normal responses to thermal tests. Radiographic examination of the tooth indicated dentin-bridge formation in the pulp chamber and the continuous root formation. This case report demonstrates a fast tissue response both at the pulpal and root dentin level. The use of tricalcium silicate cement should be considered as a conservative intervention in the treatment of symptomatic immature teeth.