• Restorative Dentistry and Endodontics
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• v.29 no.3
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• pp.226-232
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• 2004

Use of electric pulp testing elicits painful response in vital teeth. In this study, we examined the excessive time from pain feeling to stimulation disconnection in clinical situation. D626D (Parkell Inc., USA.) scan type electric pulp tester was used in total of 23 young healthy individuals. Each of the right central incisors and first premolars were used as testing teeth. Stimulation disconnection was achieved by EMG in anterior belly of digastric muscle, finger span, and voice and the excessive stimulation time over the sensory thresh-old was recorded. As a result, we found that the short responses before the stimulation disconnection appeared following order：EMG, finger span, and voice. The EMG disconnection is suggested to be used to reduce the excessive stimulus time in electric pulp testing.

• Journal of the korean academy of Pediatric Dentistry
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• v.38 no.4
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• pp.399-406
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• 2011

Traumatic injury on tooth occurs frequently among trauma patients, and mainly occurs on tooth with premature roots which influences pulp tissue, periodontal ligament, alveolar bone, and Hertwig's epithelial root sheath. According to the degree of trauma, a number of kinds of healing process can be observed, such as complete re-vascularization of pulp, root canal obliteration, growth suspension of root apex, and invasion of alveolar bone into root canal, and there can be some complications such as necrotic change of inflammatory root resorption and partial pulp necrosis due to pulp necrosis toward complete necrosis. In this clinical case, 3 patients who had traumatic injury showed root growth suspension and alveolar bone invasion into root canal due to proliferation of periodontal ligament cell and osteocyte at the base of extraction socket into pulp chamber because of the injury on Hertwig's epithelial root sheath. If intrusion of alveolar bone into root canal due to injury on Hertwig's epithelial root sheath after having traumatic injury doesn't show any complication, the pulp may be considered to have normal vitality and doesn't need any further treatment, therefore differential diagnosis is very necessary. However, it may be accompanied with suspension of root growth, therefore, additional trauma during the treatment of injured tooth should not be applied.

• Journal of Periodontal and Implant Science
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• v.25 no.3
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• pp.539-556
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• 1995

Periodontal therapeutic modalities should be re-establishing and regenerating the periodontal tissue previously lost to the disease. To achieve periodontal regeneration, periodontal ligament cells must selective migrate to the deneded root surface, attached and proliferated it. Local pH concentration is one of the most factors that periodontal regeneration. The aims of this study were to examine on biological effects of pH to the human periodontal ligament cells in vitro, especially on the cell morphology, attachment, activity, vitality and viability. Human periodontal ligament cells were cultured from extracted tooth for non-periodontal reason. Immediately after extraction, any soft tissue adhering to the cervical parts of the roots was carefully removed with a sterile curette. To produce different pH levels in the media, Eagle's MEM was adjusted from pH 6.6 to 8.2 in 0.2 intervals with 1 M NaOH and 1 N HCl. After cultivation, Then, Periodontal ligament cells were cultured at pH ranging from 6.6-8.2. attachment assay was done at 1, 2 day incubation and activity assay was done at 1, 2, 3 day incubation. The experiments were evaluated by scaning electron microscopic techniques (HITACHIX-650 Scaning Electron Microanalyzer, Tokyo, Japan), MTT assay, and the cultured periodontal ligament cells were fixed in neutral formalin for 24 hours and immunohistochemically processed by PCNA for proliferating ability. The surviving cells in the medium showed slightly increased volume and widening intercellular distances at low concentration of pH than control group (pH 7.4), and apparently shrinkage at high concentration of pH than control group (pH 7.4). The results of the statistical analysis from the experiment on attachment, vitality and viability were as follows. Attachment of periodontal ligament cells at 1st and 2nd day, similar attachment rate of low concentration pH compared with control value (pH 7.4). But above pH 8.0, attachment rate were statistically significant decrease from control value(P<0.05). Periodontal ligament cell's activities were maximum at pH 7.6 by MTT assay. Similar with control value at low concentration of pH. But, the activities were statistically significant decrease at high concentraration of pH(P<0.05). Cellular proliferating rate (PCNA index) were statistically significant decrease from control value at low and high concentration of pH(p<0.05). This results suggested that hjgh concentration pH, in other words, alkali pH was cytotoxic effects on human periodontal ligament cells in vitro.

• Journal of Periodontal and Implant Science
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• v.32 no.2
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• pp.371-378
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• 2002

In this study, 40 hypersensitive teeth of 19 patients were investigated. The procedures performed were as follows: Before desensitization, EPT at occlusal third of buccal surface was done for the evaluation of pulp vitality and the EPT value was recorded for the reference value. And mechanical and thermal test was executed for the test of hypersensitivity. If the tooth responded to the above tests, we did EPT at the exposed surface, using toothpaste as a electrolite medium and recorded the EPT value at patient's response. After the tests had been done, desensitization procedures with Gluma(R) Desensitizer were performed according to the manufacturer's instructions. After desensitization, the same tests except EPT at occlusal third were repeated. All the 40 teeth responded positive before desensitization and negative after desensitization procedures. The EPT value at occlusal third ranged from 31 to 65 (48.9${\pm}$7.2). Before desensitization 34 teeth responded at EPT value of 2 and the remaining 6 teeth was in the range of 17 to 25. After desensitization all 40 teeth responded from 12 to 27 (19.6${\pm}$3.5). The 6 teeth responded at greater number than 2 before desensitization was in the range of 18 to 23. Within the limitations of this study we can conclude that: When a tooth with dentinal hypersensitivity responds to mechanical and thermal stimulation, the tooth shows very low resistance to electricity at the exposed surface while when a tooth is desensitized and doesn't show respond to mechanical and thermal stimuli, the tooth shows increased level of resistance to electric stimulation at the exposed surface. EPT can be used for the diagnosis of dentinal hypersensitivity. Furthermore EPT will be useful to evaluate the outcome of desensitization procedures. However, EPT is not a valid tool for measuring dentinal hypersensitivity.

• Journal of the korean academy of Pediatric Dentistry
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• v.43 no.2
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• pp.200-206
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• 2016

Root fracture is defined as a fracture involving the dentin, cementum, and pulp. Most fractures occur in the maxillary anterior teeth between the ages of 11 and 20 years old. The treatment for root fracture in permanent teeth involves the reduction and fixation of the displaced coronal segment. When signs of pulp necrosis or inflammatory root resorption are present, root canal therapy should be performed. Since most apical fragments maintain pulp vitality, root canal therapy is typically limited to coronal fragments. However, it's too difficult to achieve a proper apical stop on coronal fragment. Intentional replantation involves performing root apex treatment outside the mouth after intentional extraction of the tooth in a controlled environment and then replanting it. The objective is 'perfect' root canal therapy. Intentional replantation may be used in cases of failed typical root canal therapy, problematic endodontic retreatment due to the existing restoration or a calcified root canal, and when apical surgery is contraindicated because of a lack of reasonable approaches. In this case, intentional replantation was carried out to treat a horizontal root fracture in a maxillary central incisor with a calcified root canal due to previous trauma. We achieved a clinically and functionally satisfactory result.

• The Journal of Advanced Prosthodontics
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• v.10 no.1
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• pp.18-24
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• 2018

PURPOSE. In literature, many studies compare survival rates of different types of FPDs. Most of them compared restorations, which originated from one university, but from different clinicians. Data about restoration survival rates by only one experienced dentist are very rare. The aim of this study was to evaluate the survival rate of all-ceramic FPDs without the blurring effects of different clinicians. MATERIALS AND METHODS. 153 veneered-zirconia FPDs were observed for follow-up. 22 patients received 131 single crowns and 22 bridges. Because of the different bridge lengths, one unit was defined as a restored or replaced tooth. In total, 201 units were included. Only the restorations performed by the same clinician and produced in the same dental laboratory from 2011 to 2016 were included. Considered factors were defined as "type of unit", "type of abutment", "intraoral region", and "vitality". Modified UHPHS criteria were used for evaluation. Statistical analysis was performed using cox-regression. RESULTS. 189 units (94.0%) showed no kind of failure. 5 chippings (2.4%) could be corrected by intraoral polishing. 4 units (1.9%) exhibited spontaneous decementation. These polishable and recementable restorations are still in clinical use. Chippings or decementations, which lead to total failure, did not occur. One unit was completely fractured (0.5 %). Biological failures (caries, periodontitis or periimplantitis) did not occur. The statistical analysis of the factors did not reveal any significant differences. CONCLUSION. Modern all-ceramic FPDs seem to be an appropriate therapy not only for single restorations but for complex occlusal rehabilitations.

• Journal of the korean academy of Pediatric Dentistry
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• v.30 no.3
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• pp.385-390
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• 2003

Traumatic injuries in the young permanent dentition are common, but root fractures, defined as fractures involving dentin, cementum and pulp, are relatively uncommon. Appropriate management of root fracture involves repositioning the coronal portion of the tooth fragment and firm immobilization with a splint for 2 to 3 month. Root canal treatment should not be initiated until the sign of necrosis or resorption are apparent because in most cases, the apical fragments maintain their vitality. The following case report describes a patient with root fractures injured three times over the period of 7 years. The results, clinically and radiographically, were acceptable, but long term periodic evaluation is required.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.23 no.4
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• pp.338-347
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• 2001

Purpose: This is to review the cases of posterior maxillary segmental osteotomies to regain the interarch spaces for dental implants in the posterior mandible. Materials & Methods: Seven patients who presented with alveolar extrusion of upper posterior molars underwent segmental osteotomies by single-stage Kufner's buccal approach under the intravenous sedation and local anesthesia. The posterior maxillary cento-alveolar segments were repositioned upward using pre-fabricated palato-occlusal resin splints and immobilized with osteosynthesis microplates and screws. Dental implants were installated simultaneously. The regained spaces, tooth vitality, periodontal healing, relapse, tenderness on function, and complications including maxillary sinus involvements were evaluated periodically for over one year after the surgeries. Results: The single-tage procedures were completed within 80 minutes without any surgical complications. The posterior maxillary segments were repositioned upward to regain the interarch spaces ranging from 2.5 to 5.5mm. All teeth involved in the procedures keep their vitalities. The repositioned segments were maintained showing neither evidence of periodontal break-down nor tenderness to function. One patient whose segments had not been immobilized by osteosynthesis plate resulted in 2mm down-ward relapse in post-operative 8 months. A case of postoperative nasal bleeding from the posterior-lateral wall resulted in oroantral fistula and chronic maxillary sinusitis later. Conclusion: The extruded dento-alveolar segments of the posterior maxilla were repositioned properly by Kufner's one-stage segmental osteotomies. One microplate can be of help to keep the position until the osseous healing enough to support the masticatory force.

• Journal of Veterinary Clinics
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• v.24 no.1
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• pp.62-67
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• 2007

Two cases of vital pulpotomy for treatment of open fractured canine teeth in dog were referred to the Veterinary Teaching Hospital of College of Veterinary Medicine, Chonnam National University. In case 1, a 2-year-old male Locker. Spaniel was fractured left mandibular canine and the pulp was exposed. In case 2, an 1-year-old male Border Collie was open fractured both mandibular canine teeth. In both cases, we made sure of pulp vitality by oral examination and radiological findings. Therefore, we performed vital pulpotomy in these patients. Two months after therapy, radiological examinations were performed for evaluation of success of therapy. In both cases the radiographs showed normal periapical anatomy and no changes in the root resorption.

• Journal of the korean academy of Pediatric Dentistry
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• v.40 no.2
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• pp.127-132
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• 2013

Traumatic injuries to immature permanent teeth are common and the results can be destructive. Although Hertwig's epithelial root sheath is usually sensitive to trauma, it may resist damage from trauma thereby retaining its vitality and continuing to calcify a root under favorable conditions. This case report describes two cases of trauma to immature permanent incisors. The first case presents an avulsed maxillary central incisor which has been replanted. The other case shows completely avulsed mandibular central incisors which have not been replanted. However, both cases subsequently show continued growing roots separated from the main roots. This report highlights the ability of the immature pulp tissue to continue to form dentin and the robustness of Hertwig's epithelial root sheath to initiate root development despite a traumatic injury.