No abstract available.
Therapeutic Equivalency*

No abstract available.
Nickel ; Titanium

Mechanical properties and microleakage of two composites [conventional hybrid type DenFil (VERICOM Co., Anyang, Korea) / micro matrix hybrid type Esthet X (Dentsply Caulk, Milford, DE, U.S.A.)] were evaluated to assess whether variable light intensity curing is better than conventional curing technique. Curing was done for 40 seconds in two ways of 2 step soft-start technique and 5 step ramping technique. Three kinds of light intensities of 50, 100, 200 mW/cm2 were initially used for 10, 20, 30 seconds each and the maximum intensity of 600 mW/cm2 was used for the rest of curing time in a soft-start curing technique. In a ramping technique, curing was done with the same initial intensities and the light intensity was increased 5 times with the same rate to the maximum intensity of 600 mW/cm2. After determining conditions that showed no different mechanical properties with conventional technique, Esthet X composite was filled in a class V cavity, which dimension was 4x3x1.5 mm and cured under those conditions. Microleakage was evaluated in two ways of dye penetration and maximum gap estimation through SEM observation. ANOVA and Spearman's rho test were used to confirm any statistical significance among groups. The results were as follows: 1. Several curing conditions of variable light intensities resulted in the similar mechanical properties with a conventional continuous curing technique, except conditions that start curing with an initial light intensity of 50 mW/cm2, 2. Conventional and ramping techniques were better than soft-start technique in mechanical properties of microhardness and compressive strength. 3. Soft-start group that started curing with an initial light intensity of 100 mW/cm2 for 10 seconds showed the least dye penetration. Soft-start group that started curing with an initial light intensity of 200 mW/cm2 for 10 seconds showed the smallest marginal gap, if there was no difference among groups. 4. Soft-start technique resulted in better dye-proof margin than conventional technique (p=0.014) and ramping technique(p=0.002). 5. There was a very low relationship(p=0.157) between the methods of dye penetration and marginal gap determination through SEM evaluation. From the results of this study, it was revealed that ramping technique would be better than conventional technique in mechanical properties, however, soft-start technique might be better than conventional one in microleakage. It was concluded that much endeavor should be made to find out the curing conditions, which have advantages of both aspects or to solve these kinds of problems through a novel idea of polymerization.
Architectural Accessibility ; Compressive Strength ; Gyeonggi-do ; Polymerization ; Polymers

This study was performed to analyse the expression of VEGF and it's receptor(VEGFR) in the tension side of the periodontal ligament following orthodontic tooth movement. Upper first molars of Sprague-Dawley rats were moved medially using closed coil spring for 1, 2, 24 hours and 3, 7, 14 days. H&E staining, immunohistochemical staining and in situ hybridization methods were used to analyse the change of the expression of VEGF and VEGFR. The results from this study were as follows : 1. Following tensional force, periodontal ligament showed elongation of fibers, compression and congestion of vessels and regional hemorrhage. These tissue changes were recovered within 3 days of force application. New bone formation was seen after 3 days of force application and continued for the remaining experimental periods. 2. Following tensional force, VEGF and VEGF mRNA expression was increased in the periodontal ligament cells, osteoblasts and cementoblasts. This change was followed by increased vasculature in the periodontal ligament. 3. After 3 days of tensional force, VEGF and VEGF mRNA expression was confined mainly to the osteopaths and the periodontal ligament cells adjacent to the alveolar bone. After 2 weeks of force application, VEGF and VEGF mRNA expression was reduced to the level of control sample. 4. VEGFRs(Flt-1, Flk-1) showed similar expression pattern and it's expression was mainly seen in the endothelial cells and osteoblasts. Following tensional force VEGFR expression was increased in the endothelial cells and osteoblasts. In conclusion, in the tension side of the periodontal ligament, ligament cells, osteoblast and cementoblast showed increased expression of VEGF & VEGF mRNA. It preceded the increase of vasculature and new bone formation. The increased expression of VEGF mRNA in cementoblast may induce periodontal vessels, which distribute mainly the bone side half of periodontal ligament, grow in the direction of tensional force. Increased expression of VEGFR & VEGFR mRNA not only in endothelial cell but in osteoblast, osteocyte and periodontal cells showed VEGF acts not only in paracrine manner but in autocrine one.
Animals ; Dental Cementum ; Endothelial Cells ; Estrogens, Conjugated (USP) ; Hemorrhage ; Humans ; In Situ Hybridization ; Ligaments ; Molar* ; Osteoblasts ; Osteocytes ; Osteogenesis ; Osteopathic Physicians ; Periodontal Ligament* ; Rats* ; Rats, Sprague-Dawley ; RNA, Messenger ; Tooth Movement* ; Tooth* ; Vascular Endothelial Growth Factor A*

Otolaryngologists are sometimes confronted with various complications. They may be minor or sometimes they can be major, and rarely fatal. Some complications can be prevented, but some are unavoidable. Five cases of major complications, which occurred during or after routine rhinologic surgery, are presented. Two patients died of toxic shock syndrome: one patient after endoscopic sinus surgery (ESS) and the other patient after closed nasal bone reduction. One patient died of acute myocardial infarction during the recovery of anesthesia after uneventful ESS. One patient had a lidocaine shock, which required treatment in the intensive care unit. One patient had a transient unilateral blindness after intranasal steroid injection. Though the 3rd and 4th cases of complications were unavoidable, the others could have been prevented if precautions had taken place. The presumed pathophysiology, possible prevention measures, and their implications in routine otolaryngologic surgery are discussed.
Anesthesia ; Blindness ; Humans ; Intensive Care Units ; Lidocaine ; Myocardial Infarction ; Nasal Bone ; Shock ; Shock, Septic

Maxillary canines have less anatomical diversities than other teeth. They usually have a single root and root canal. This report describes an endodontic treatment of a maxillary canine with two separated root canals which have not been reported through the demonstration of radiography and computerized tomography (CT). Even though appropriated endodontic treatment has been performed, the severe pain could happen due to lack of consideration of anatomical variations of the teeth. Therefore, the clinicians should be well aware of the possibility of anatomical variations in the root canal system during endodontic treatment even if the number of root canals is obvious such as in this case.
Dental Pulp Cavity ; Tooth

Several ways of curing are being tried to improve material's properties and reduce marginal gap. However, all are considering about the pattern of light intensity. It was noted from the preliminary study the change of light wavelength from filter changing may give an impact on material's property and microleakage. The object of this study was to verify the effect of filters with various wavelength width on the microhardness and microleakage of composite resin; hybrid type of DenFil and submicron hybrid type of Esthet X. Composite resins were cured using 3 kinds of filter; narrow-banded(465-475 nm), mid-banded(430-470 nm), wide-banded(400-500 nm). After the estimation of microhardness, degree of dye penetration and the maximum gap from SEM evaluation were done between 4 groups that showed no difference in microhardness value of the lower surface. The results were as follows: 1. Adequate microhardness could not be gained with a narrow-banded filter irrespective of curing time. At the upper surface, DenFil should be polymerized with middle or wide-banded filter for 20 seconds at least, while Esthet X be cured with middle or wide-banded filter for 30 seconds at least to get similar hardness value to control group. 2. There was little dye penetration in enamel margin, but all dentin margins showed much more dye penetration irrespective of curing conditions. Although there was no statistical difference, groups cured with mid-banded filter for 40 seconds and with wide-width filter for 20 seconds showed relatively less dye penetration. 3. It was revealed from the SEM examination that group cured with wide-banded filter had the smallest gap without statistical significance. Spearman's rho test showed that the correlation between the results of dye penetration and SEM examination was very low. From these results, it could be concluded that curing with wide-width filter would be better than the other techniques, even though the curing technique using mid-width filter seems to have its own unique advantage.
Chimera ; Composite Resins ; Dental Enamel ; Dentin ; Hardness ; Imidazoles ; Light ; Nitro Compounds ; Polymers

The institutional review board is crucial to ensure the scientific and ethical quality of human participant research. This paper analyzes a survey on the current constitution and operation of institutional review boards (IRBs) in Korea, conducted by the Korean Association of Institutional Review Boards in April 2002. Out of 74 IRBs, 63 responded to the survey (85.1% response rate). IRB membership has a male-to-female ratio of approximately 80:20, a predominance of male clinicians (60%) and an underrepresentation of community people unaffiliated to the institutions (less than 10%). Most IRBs (around 80%) confine the scope of their reviews to the clinical evaluation of drugs or devices, leaving the remaining areas of research involving human participants untouched. As their role is limited, the majority of IRBs do not operate actively: 72% of responding IRBs reviewed less than one protocol per month in 2001. Sixty two percent of institutions have never discussed the need for insuring research participants' risks or making indemnity arrangements. This survey reveals many shortcomings and points for improvement by the institutional support bodies, including the need to establish regular education programs for IRB members and investigators.
Appointments and Schedules ; Clinical Trials/legislation & jurisprudence ; Clinical Trials/standards ; Data Collection ; Epidemiologic Studies ; Ethics Committees, Research*/legislation & jurisprudence ; Ethics Committees, Research*/standards ; Ethics Committees, Research*/statistics & numerical data ; Female ; Human ; Human Experimentation/legislation & jurisprudence ; Human Experimentation/standards ; Korea ; Male ; Politics ; Public Policy ; Research Design/standards

STUDY DESIGN: A retrospective study OBJECTIVES: To introduce the technique of minimally invasive transforaminal lumbar interbody fusion and examine its clinical and radiologic results. SUMMARY OF LITERATURE REVIEW: Transforaminal lumbar interbody fusion with a mini-incision using a tubular retractor was recently developed. The aim of this procedure is to reduce the approach-related morbidity and achieve better results in an effective and safe manner. MATERIALS AND METHODS: Thirty eight patients were followed up for more than 1 year. Their mean age was 57 years and the mean follow-up was 19 months. The diagnosis was spinal stenosis, spondylolisthesis and recurred herniated nucleus pulposus in 22, 14 and 2 patients, respectively. The Oswestry disability index, intervertebral disc space height, fusion rate and complications were evaluated. RESULTS: The Oswestry disability index improved from 30 points (range, 50~16 points) to 10 points (range, 2-24 points) at the last follow-up. Thirty-four patients (90%) showed excellent or good results. The intervertebral disc space height increased from 8.7 mm to 10.8 mm. Two cases showed nonunion but the clinical results were good. Complications included one case of infectious spondylitis requiring antibiotics, one case of cage dislodgement requiring additional surgery and one case of a pedicle screw malposition showing no clinical symptoms. CONCLUSIONS: Minimally invasive transforaminal lumbar interbody fusion reduced the soft tissue injury and blood loss and shortened the recovery period compared to the traditional open techniques.
Anti-Bacterial Agents ; Follow-Up Studies ; Humans ; Intervertebral Disc ; Retrospective Studies ; Soft Tissue Injuries ; Spinal Stenosis ; Spondylitis ; Spondylolisthesis

PURPOSE: To find out the advantages and disadvantages of the suture technique and improve the method of operation. MATERIALS AND METHODS: Postoperative follow-up of at least one year was possible in thirteen cases including 7 surgical neck fractures and 6 three-part fractures. The results were analysed radiographically and clinically using a modified UCLA scale. RESULTS: There was one non-union and except for that case, the average union time was 10.2 weeks. Active forward flexion averaged 140 degrees, external rotation 50 degrees and internal rotation between T12 and L1 vertebra. The clinical results were 3 excellent, 5 good and 4 fair. There was no significant corelation (P=0.538) between fracture type and clinical results statistically. But for above 65 years, the UCLA scale averaged 25.8 points and for under 65 years, 31.6 points (P=0.006 ) . CONCLUSION: The use of a suture technique for these displaced fracture without the use of metals achieved a high percentage of acceptable results. But in order to achieve good stability and early exercise, the neck fragment had to be impacted into the humeral head and the medial and lateral part of the neck fracture should be fixed together. Therefore, it is difficult to use this method for severely comminuted neck fractures.
Follow-Up Studies ; Humeral Head ; Metals ; Neck ; Shoulder Fractures* ; Spine ; Suture Techniques* ; Sutures*