• The Journal of Advanced Prosthodontics
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• v.3 no.2
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• pp.90-95
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• 2011

PURPOSE. To compare the fracture resistance and the mode of failure of endodontically treated teeth restored with different post-core systems. MATERIALS AND METHODS. Root canal treatment was performed on 40 maxillary incisors and the samples were divided into four groups of 10 each. For three experimental groups post space preparation was done and teeth were restored with cast post-core (Group B), stainless steel post with composite core (Group C) and glass fiber post with composite core using adhesive resin cement (Group D). Control group (A) samples were selected with intact coronal structure. All the samples were prepared for ideal abutment preparation. All the samples were subjected to a load of 0.5 mm/min at $130^{circ}$.until fracture occurred using the universal testing machine. The fracture resistance was measured and the data were analyzed statistically. The fracture above the embedded resin was considered to be favorable and the fracture below the level was considered as unfavorable. The statistical analysis of fracture resistance between different groups was carried out with t-test. For the mode of failure the statistical analysis was carried out by Kruskal-Wallis test and Chi-Square test. RESULTS. For experimental group Vs control group the fracture resistance values showed significant differences (P<.05). For the mode of failure the chi-square value is 16.1610, which means highly significant (P=.0009) statistically. CONCLUSION. Endodontically treated teeth without post core system showed the least fracture resistance demonstrating the need to reinforce the tooth. Stainless steel post with composite core showed the highest fracture resistance among all the experimental groups. Teeth restored with the Glass fiber post showed the most favorable fractures making them more amenable to the re-treatment.

• Journal of Dental Anesthesia and Pain Medicine
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• v.17 no.1
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• pp.47-53
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• 2017

Background: Every patient who undergoes mandibular third molar surgery is concerned about post-operative pain. Indeed, previous researchers have used various methods to treat such pain. This study aimed to assess the effectiveness of sublingual injection of dexamethasone (8 mg) to treat post-operative pain after mandibular third molar surgery. Method: This was a randomized, double-blind, split-mouth, clinical trial, involving 48 healthy patients who required surgical removal of two mandibular third molars with similar bilateral positions. All operations were performed by the same experienced surgeon. The patients were randomized into a study group (8 mg dexamethasone injection) and a placebo group (normal saline injection). Both interventions were injected into the sublingual space immediately after local anesthesia, 30 min before the first incision. The study group received an 8 mg dexamethasone injection, while the placebo group received a normal saline injection. The wash period between the patients' two operations was 3 to 4 weeks. Pain was assessed by recording the number of analgesic tablets (rescue drug) consumed, as well as by noting the patients' responses to the visual analog scale (VAS) on the first, second, and third days after surgery. Results: The study group differed significantly from the placebo group in terms of VAS score and analgesic consumption. Conclusion: Dexamethasone (8 mg), injected sublingually, significantly eased post-operative pain after surgical removal of the mandibular third molar.

• The Journal of Korean Academy of Prosthodontics
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• v.53 no.3
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• pp.215-221
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• 2015

Treating patients with severely worn dentition often requires comprehensive prosthetic treatments. Oral rehabilitation and long-term stability could be achieved by analyzing the cause of the wear and changing vertical dimension. The temporary restoration procedure is executed and patient's adaptation is evaluated by long-term observation when treatment is accompanied with increasing vertical dimension. In this case, 54 year-old male presented with worn dentition and esthetic dissatisfaction. In oral manifestations, severely worn dentition with attrition and erosion is diagnosed. To evaluate change of vertical dimension, interocclusal rest space, facial appearance, pronunciation, clinical crown length, distance from incisor edge to labial vestibule are evaluated. Consequently, 2.5 mm increase of vertical dimension that based on articulator incisal pin is determined. After 8 weeks stabilization period with temporary prostheses, definitive prostheses are fabricated. After 6 months follow up period, satisfactory outcomes were achieved both in functional and esthetic aspects through this procedure.

• The Journal of Advanced Prosthodontics
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• v.6 no.4
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• pp.295-301
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• 2014

PURPOSE. Numerous methods were used to etch the fiber posts to improve its bonding to root canal dentin. Our aim was to evaluate the efficacy of 37% phosphoric acid in etching fiber posts in comparison with 24% hydrogen peroxide. MATERIALS AND METHODS. Ninety human maxillary central incisors were taken and post space preparation was done. Ninety fiber posts were taken and divided into three groups (n=30) based on the surface treatment they received ($H_3PO_4$, $H_2O_2$, distilled water) and each group was further divided (n=10) based on the time period of application (15 seconds, 30 seconds, 60 seconds). All the posts were luted into canals using Rely X UniCem-2. Each tooth was then sectioned into six slices and subjected to push out test. Data obtained was subjected to statistical analysis at P<.05. The surface topography was evaluated using scanning electron microscopy. RESULTS. Highest bond strength values were noted in 15 seconds etched phosphoric acid group and 60 seconds etched hydrogen peroxide group with no significant difference between two groups. Surface topography revealed complete epoxy layer removal with no damage to its structural integrity in those groups. CONCLUSION. $H_3PO_4$ etching for a period of 15 seconds is an effective alternative in improving the adhesion of fiber post to root dentin.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.27 no.5
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• pp.431-437
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• 2005

Fibrin glue is composed of fibrinogen and thrombin and used in various regions for multiple use. Basic principle is that thrombin converts fibrinogen to fibrin in the presence of $Ca^{2+}$. The structure of fibrin is loose at the beginning, but after about 5 minutes a tight structure is formed under the influence of factor VIII which changes fibrin monomer into fibrin polymer. Fibrin glue is used for tissue adhesive, suture, local hemostasis, wound healing, closure of subdural space. Fibrin adhesive has been used in oral and maxillofacial surgery for hemostasis after tooth extraction in patients with coagulation disorders, skin graft fixation, reattachment of periodontal flaps, in combination with autogenous bone chips to fill the bony cavities following cyst removal, and for securing the hydroxyapatite granules for maxillary alveolar ridge augmentation. This study was designed for researching influence of fibrin glue during healing phase after making artificial bone defect.

• The korean journal of orthodontics
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• v.45 no.5
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• pp.236-244
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• 2015

Objective: The aim of this study was to investigate three-dimensional molar displacement after distalization via miniscrews and a horizontal modification of the trans-palatal-arch (TPA). Methods: The subjects in this clinical trial were 26 Class II patients. After the preparation of a complete set of diagnostic records, miniscrews were inserted between the maxillary 2nd premolar and 1st molar on the palatal side. Elastic modules connected to the TPA exerting an average force of 150-200 g/side parallel to the occlusal plane were applied. Cone-beam computed tomography was utilized to evaluate the position of the miniscrews relative to the adjacent teeth and maxillary sinus, and the direction of force relative to molar furcation. The distances from the central point of the incisive papilla to the mesiopalatal cusps of the 1st maxillary molars and the distances between the mesiopalatal cusps of the left and right molars were measured to evaluate displacement of the maxillary molars on the horizontal plane. Interocclusal space was used to evaluate vertical changes. Results: Mean maxillary 1st molar distalization was $2.3{\pm}1.1mm$, at a rate of $0.4{\pm}0.2mm/month$, and rotation was not significant. Intermolar width increased by $2.9{\pm}1.8mm$. Molars were intruded relative to the neighboring teeth, from 0.1 to 0.8 mm. Conclusions: Distalization of molars was possible without extrusion, using the appliance investigated. The intrusive component of force reduced the rate of distal movement.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.44 no.1
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• pp.18-24
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• 2018

Objectives: Foreign bodies (FBs) account for 3.8% of all pathologies of the head and neck region, and approximately one third of them are missed on initial examination. Thus, FBs represent diagnostic challenges to maxillofacial surgeons, rendering it necessary to employ an appropriate imaging modality in suspected cases. Materials and Methods: In this cross-sectional study, five different materials, including wood, metal, glass, tooth and stone, were prepared in three sizes (0.5, 1, and 2 mm) and placed in three locations (soft tissue, air-filled space and bone surface) within a sheep's head (one day after death) and scanned by panoramic radiography, cone-beam computed tomography (CBCT), and ultrasonography (US) devices. The images were reviewed, and accuracy of the detection modalities was recorded. The data were analyzed statistically using the Kruskal-Wallis, Mann-Whitney U-test, Friedman, Wilcoxon signed-rank and kappa tests (P<0.05). Results: CBCT was more accurate in detection of FBs than panoramic radiography and US (P<0.001). Metal was the most visible FB in all of modalities. US was the most accurate technique for detecting wooden materials, and CBCT was the best modality for detecting all other materials, regardless of size or location (P<0.05). The detection accuracy of US was greater in soft tissue, while both CBCT and panoramic radiography had minimal accuracy in detection of FBs in soft tissue. Conclusion: CBCT was the most accurate detection modality for all the sizes, locations and compositions of FBs, except for the wooden materials. Therefore, we recommend CBCT as the gold standard of imaging for detecting FBs in the maxillofacial region.

• Journal of the korean academy of Pediatric Dentistry
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• v.2 no.1
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• pp.67-75
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• 1975

The conserative treatment of the necrotic and infected primary molars is often necessary in order to avoid extractions which may lead to inability to masticate or loss of space and subsequent problems concerning the development of the occlusion in the permanent dentition. The purpose of this study was to evaluate the clinical significance of the conservative treatment of the infected primary molars with necrotic pulps employing the formocresol pulpotomy technique same as in vital teeth and surgical intervention in the cases with a parulis, fistula or cellulitis. The materials consisted of 25 primary molars of 9 boys and 4 girls ranging in age from 4 to 7 years. This study included clinical and radiographic observation at 3-month intervals postoperatively. The following results were obtained. 1. Clinically, 20 cases of 25 were successful, exhibiting no clinical problems such as fistula, mobility, toothache and tenderness to percussion, etc. 5 cases were regarded as failures. 2. Radiographiclly, 14 cases revealed normal features, in 6 cases slight rarefaction was observed in the periapical and interradicular region, and marked periapical and interradicular rarefaction was observed in 5 cases. 3. Marked bony deposition was observed in the periapical and interradicular regions in all the remainder except for 5 failurese. 4. Pathologic root resorption was observed in 2 cases. 5. No alveolodental ankylosis was observed. 6. Regeneration of the dental sac of the permanent tooth was observed in 1 case of 2 cases which had revealed loss of the dental sac.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.41 no.1
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• pp.3-10
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• 2015

Objectives: We retrospectively evaluated the impact of mandibular third molars on the occurrence of angle and condyle fractures. Materials and Methods: This was a retrospective investigation using patient records and radiographs. The sample set consisted of 440 patients with mandibular fractures. Eruption space, depth and angulation of the third molar were measured. Results: Of the 144 angle fracture patients, 130 patients had third molars and 14 patients did not. The ratio of angle fractures when a third molar was present (1.26 : 1) was greater than when no third molar was present (0.19 : 1; odds ratio, 6.58; P<0.001). Of the 141 condyle fractures patients, the third molar was present in 84 patients and absent in 57 patients. The ratio of condyle fractures when a third molar was present (0.56 : 1) was lower than when no third molar was present (1.90 : 1; odds ratio, 0.30; P<0.001). Conclusion: The increased ratio of angle fractures with third molars and the ratio of condyle fractures without a third molar were statistically significant. The occurrence of angle and condyle fractures was more affected by the continuity of the cortical bone at the angle than by the depth of a third molar. These results demonstrate that a third molar can be a determining factor in angle and condyle fractures.

• Journal of the korean academy of Pediatric Dentistry
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• v.28 no.2
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• pp.316-322
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• 2001

Chemotherapy and radiotherapy used on pediatric oncology patients often causes dentofacial anomalies. Defects noted include tooth and root agenesis, root thinning, root shortening, localized enamel defect and maxillofacial underdevelopment. The effect of radiotherapy usually is confined to the radiation site but the effect of chemotherapy may be more wide spread becuase of its systemic distribution. Many pediatric cancers are treated with a combination of radiation and multiagent chemotherapy. Dental treatment affected by chemotherapy and radiation therapy damage to developing teeth and maxilloface includes retention of teeth, space maintenance, prosthetic considerations, requirements for oral hygiene. The following case related to multiple rootless teeth.