• The Journal of the Korean dental association
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• v.40 no.7 s.398
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• pp.542-547
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• 2002

This study was aimed to help diagnose the vertical root fractures in endodontically and in nonendodontically treated teeth. This was a study about mine teeth with a vertical root fractures. Four cases were nonendodontically treated teeth and five cases were endodontically treated teeth. A collection of information including past dental history, periodontal probing, and X-ray was gathered on each case. One of the endodontic cases had no periodontal pocket depth and was in acute pain. It was confusing to find whether causes were because of endodontic failure or vertical root fractures. Most of the vertical root fractures were found in patients aged between 50 and 60. Vertical root fractures were found in the molar and premolar of maxillary and mandibular teeth. The second molars repecially, which had C shaped roots had vertical root fractures with apical propagation type. The apical propagation type means that vertical root fracture initiates in root apex and propagate to coronal root. The teeth with vertical root fractures of the apical propagation type, which was in acute pain, were very difficult in differential diagnosis of periodontal lesion and endodontic failure. Therefore, the dental history was very important to make a differential diagnosis. Past pain history repeated uncomfortable symptoms in bite was a key of differential diagnosis.

• Restorative Dentistry and Endodontics
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• v.22 no.2
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• pp.792-800
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• 1997

The purpose of this study was to evaluate the adaptation of self-cured glass ionomer cement and resin-modified glass ionomer cement and polyacid-modified resin composite, which are light-cured giass ionomer cements, to dentin surface. Twelve extracted human maxillary and mandibular molar teeth were used in this study. The entire occlusal dentin surfaces of teeth were exposed with Diamond Wheel Saw and smoothed with sand papers (300, 600, 1200grits). They were randomly assigned into 3 groups according to glass ionomer cements used; Control group- Fuji II, Expeimental group 1 - Fuji II LC, Expeimental group 2 - Dyract. According to the manufacturer's directions, three glass ionomer cements were bonded to exposed dentin surfaces of the tooth crown and cured. Crowns and glass ionomers were trimmed after 24hrs and sectioned horizontally and vertically with diamond saw. The interface of glass ionomer cements and dentin was examined under SEM. The results were as follows : 1. Good adatation between glass ionomer cement and dentin on the horizontal section was showed in control and experimental group 1, but the gap of $20{\mu}m$, which was observed distinct separation between glass ionomer cement and dentin, was showed in experimental group 2. 2. Good adatation between glass ionomer cements and dentin on the vertical section was showed in control and experimental group 1, but the gap of 80-$100{\mu}m$ was showed in experimental group 2. 3. Cohesive fracture within glass ionomer cements in control and experimental group 1 was showed, but no cohesive fracture was showed in experimental group 2.

• Restorative Dentistry and Endodontics
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• v.24 no.4
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• pp.657-665
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• 1999

The effects of application of mustard oil (MO), a small-fiber excitant and inflammatory irritant into the rat maxillary molar tooth pulp on arterial blood pressure and heat race, and electromyographic (EMG) activity of the jaw muscles were assessed in the anesthetized rats. In addition, Evans blue extravasation following pulpal MO application was measured. Application of MO into the tooth pulp produced a significant increase in mean arterial pressure and heat rate which gradually returned to baseline level. Application of MO into the tooth pulp induced a significant and short-lasting increase in EMG activity of digastric masseter and tongue muscle. Application of MO into the tooth pulp significantly increased the plasma extravasation of Evans blue dye. However, Application of mineral oil into the tooth pulp did not produce any significant changes in EMG activity of the digastric, masseter and tongue muscles, mean arterial pressure and heart rate, and plasma extravasation of Evans blue dye. These findings indicate that changes in arterial blood pressure, heart rate, jaw muscle activity and plasma extravasation accompanying noxious tooth pulp stimulation call be utilized as indirect measure of orofacial pain and inflammation.

• Journal of Korean Academy of Oral and Maxillofacial Radiology
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• v.23 no.2
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• pp.303-314
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• 1993

The purpose of this study was to find out the prevalence of dental anomalies in 600 normal persons (male:363, female:237) at age 14 to 39 years, through history taking, oral examination, and radiographic observations of subjects. The obtained results were as follows: 1. The prevalences of individual dental anomalies were as follows; Congenitally missing teeth 7%; supernumerary teeth 1.33%; ectopic eruption; 8.50%, transposition;0.33% rotation; 23.67%, microdontia;11.16%(peg lateralis;5.33%, third molar;5.83%), prolonged retention of deciduous teeth;1.33%, crowding 49.83%, and spacing;15.17%. 2. Alterations in numbers of teeth : The most frequently missing teeth were mandibular lateral incisors, followed by mandibular second premolars and maxillary second premolars. In numbers of congenitally missing teeth per person, 52.38% had one missing tooth and 30.95% had two missing teeth. In supernumerary teeth, there was higher rate in male than in female. Most supernumerary teeth were mesiodens of median area in maxilla and the eruption pattern of that teeth generally was unerupted state. 3. In transposition, exchange of position of teeth involved the canine and first premolar. 4. Congenital missing rate of permanent successors in prolonged retention of deciduous teeth was 69.23%. 5. Crowing and spacing had respectively higher rate in mandible and in maxilla.

• Imaging Science in Dentistry
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• v.42 no.4
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• pp.255-260
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• 2012

Dentigerous cysts are the most common developmental cysts of the jaws, most frequently associated with impacted mandibular third molar teeth. Dentigerous cysts around supernumerary teeth, however, account for 5% of all dentigerous cysts, with most developing around a mesiodens in the anterior maxilla. This report describes two cases of a dentigerous cyst associated with an impacted mesiodens. Both of the patients complained of swelling in the maxillary anterior region. Radiographic examination revealed an impacted mesiodens surrounded by a large corticated radiolucency in both cases. A provisional diagnosis of infected odontogenic cyst was made. The cysts were enucleated with the removal of the mesiodens in the two cases. Histopathological examination confirmed the diagnosis of infected dentigerous cyst associated with an impacted mesiodens in both cases. The patients remained asymptomatic, and no complications were noted.

• The Journal of Korean Academy of Prosthodontics
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• v.33 no.1
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• pp.144-155
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• 1995

It is well known that implants showing no clinical mobility are successfully osseointegrated and have good prognosis. When implants are under load, their mobility begins to increase. It is of necessity to substantiate whether excessive load is on or premature occlusal force is acting prior to desirable osseointegration. Using Periotest unit, we could measure the pattern of mobility change. Consequently, osseointegrated treatment has come to success by intercepting progressive mobility and doing perceptive treatment according to the result of Periotest Value(PTV). In this study, we took records of intangible mobility of 70 osseointegrated implants. And we also measured the mobility of periodontally sound natural teeth as a standard from 30 dental personnel. Conclusions were summarized as followings ; 1. Lower lateral incisor has the highest PTV, whereas lower canine, upper canine, lower premolars and lower 1st molar have the lowest PTV in natural dentition. 2. There are little significant statistical difference of PTV between men and women in both(natural and implant) dentition. 3. In general, lower natural teeth show lower PTV than upper counterpart. 4. Mandibular implants have lower PTV than those of maxillary implants. 5. All of the successfully osseointegrated implants have lower PTV than those of periodontally healthy teeth.

• Journal of The Korean Dental Society of Anesthesiology
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• v.11 no.2
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• pp.164-171
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• 2011

Altered consciousness may be the first clinical sign of a serious medical problem that requires immediate and intensive therapy to maintain life. There are many causes of the loss of consciousness in the dental office setting, such as, vasodepressor syncope, drug administration or ingestion, orthostatic hypotension, epilepsy, hypoglycemic reaction, acute adrenal insufficiency, cerebrovascular accident, hyperglycemic reaction, acute myocardial infarction, acute allergic reaction and hyperventilation. This is a case report of syncope and coma during endodontic treatment of a maxillary third molar under local infiltration anesthesia in multiple medically compromised patient. The main cause was thought to be hypoglycemic reaction. The patient was transferred to the medical emergency room and cared properly by the emergency medical physicians. The prognosis was good.

• Journal of Technologic Dentistry
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• v.41 no.2
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• pp.81-86
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• 2019

Purpose: The purpose of the present study was to compare the internal fit of two different temporary restorations fabricated by dental CAD/CAM system and to evaluate clinical effectiveness. Methods: Composite resin tooth of the maxillary first molar was prepared as occlusal reduction(2.0mm), axial reduction(1mm offset), vertical angle(6 degree) and chamfer margin for a temporary crown and duplicated epoxy die was fabricated. The epoxy dies were used to fabricate provisional restorations by CAD/CAM milling technique or 3D-printing technique. The inner data from all crowns were superimposed on the master die file in the 'best-fit alignment' method using 3D analysis software. Statistical analysis was performed using a Wilcoxon's rank sum test for differences between groups. Results: It showed that the internal RMS(Root Mean Square) values of the additive group were significantly larger than those of other group. No significant differences in internal discrepancies were observed in the temporary crowns among the 2 groups with different manufacturing method. Conclusion: All the groups had the internal fit within the clinical acceptable range (< $50{\mu}m$). The continuous research in the future to be applied clinically for the adaptation of additive manufacturing technique are needed.

• The Journal of Advanced Prosthodontics
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• v.14 no.6
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• pp.346-359
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• 2022

PURPOSE. Four and six implant-supported fixed full-arch prostheses with various framework materials were assessed under different loading conditions. MATERIALS AND METHODS. In the edentulous maxilla, the implants were positioned in a configuration of four to six implant modalities. CoCr, Ti, ZrO₂, and PEEK materials were used to produce the prosthetic structure. Using finite element stress analysis, the first molar was subjected to a 200 N axial and 45° oblique force. Stresses were measured on the bone, implants, abutment screw, abutment, and prosthetic screw. The Von Mises, maximum, and minimum principal stress values were calculated and compared. RESULTS. The maximum and minimum principal stresses in bone were determined as CoCr < ZrO₂ < Ti < PEEK. The Von Mises stresses on the implant, implant screw, abutment, and prosthetic screws were determined as CoCr < ZrO₂ < Ti < PEEK. The highest Von Mises stress was 9584.4 Mpa in PEEK material on the prosthetic screw under 4 implant-oblique loading. The highest maximum principal stress value in bone was found to be 120.89 Mpa, for PEEK in 4 implant-oblique loading. CONCLUSION. For four and six implant-supported structures, and depending on the loading condition, the system accumulated different stresses. The distribution of stress was reduced in materials with a high elastic modulus. When choosing materials for implant-supported fixed prostheses, it is essential to consider both the number of implants and the mechanical and physical attributes of the framework material.

• Journal of dental hygiene science
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• v.24 no.3
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• pp.200-207
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• 2024

Background: This study aimed to evaluate whether a Novel Plaque Index (NPI) using intraoral camera images would be more useful for assessing the accumulated area of dental plaque compared to three other indices. Methods: This study evaluated 80 disclosed plaque tooth surface images from 40 participants, including the facial surfaces of the maxillary left first molar and mandibular left central incisor. The tooth surface was divided longitudinally into three sections, with each section further subdivided into four subsections. A score ranging from 0 to 5 was assigned to each longitudinal third, and the average score was determined as the NPI score for the tooth surface. Two examiners assessed the NPI, Patient Hygiene Performance Index, Quigley and Hein Plaque Index, and Rustogi's Modified Navy Plaque Index scores obtained using the plaque images. The assessments were repeated twice with a 2-weeks washout period. The Plaque Percent Index (PPI) score calculated via image analysis is considered the gold standard. Results: The NPI showed the highest correlation coefficient with PPI compared to the other indices (examiner 1: 0.87, examiner 2: 0.88). The intraexaminer reliability of the NPI was excellent for both examiners. The intraclass correlation coefficient (ICC) for examiner 1 and 2 was 0.95 and 0.93, respectively. The weighted kappa values were >0.85 for both examiners. The ICC of the interexaminer analysis was 0.93 and the weighted kappa showed a reliability value of 0.81. Conclusion: The NPI was found to have greater validity and reliability than the three existing indices for the quantitative scoring of dental plaque.