• Archives of Craniofacial Surgery
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• v.13 no.2
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• pp.139-142
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• 2012

Purpose: To reconstruct the midface, local flaps such as nasolabial flaps have been frequently used. These local flaps, however, have the shortcomings of requiring a secondary operation or limitations in the movement of the flap. Thus, new methods have been developed. This paper reports a case wherein the basal cell carcinoma on the cheek was resected and the skin and soft tissue defect was successfully treated using a facial artery perforator flap. Methods: A 68-year-old female consulted the authors on the basal cell carcinoma that developed on her cheek. The mass was fully resected and revealed a $2.3{\times}2.3cm$ defective region. Using a Doppler ultrasonography, the facial artery path was traced, and using a loupe magnification, the facial artery perforator flap was elevated and the defective region was covered with the flap. Results: The flap developed early venous congestion, but it disappeared without any treatment. Six months after the surgery, the patient was satisfied with the postoperative result. Conclusion: The facial artery perforator flap has a thin pedicle. It offers a big arc of the rotation that allows free movement and one-stage operation. These strengths make the method useful for the reconstruction of the midface among other procedures.

• Restorative Dentistry and Endodontics
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• v.25 no.2
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• pp.202-211
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• 2000

The aim of this study was to compare the apical sealing ability of a new thermoplasticized gutta-percha filling technique, the Easy Filling and the Quick Obturation system with lateral condensation technique and Thermafil system to evaluate their clinical acceptabilities. Fifty-two extracted single-rooted teeth were instrumented to #35 using the .04 taper ProFile system. Four groups of 12 teeth were obturated by lateral condensation technique. Thermafil system and two new thermoplasticized gutta-percha techniques, the Easy Filling system and Quick Obturation system (Meta Dental co. Ltd. Korea), respectively. Four teeth served as controls. After the teeth were immersed in 2% methylene blue dye for 48 hours, they were resected horizontally at 1mm to 5mm level from the anatomical apex using a low-speed microtome. Each section was examined under a stereomicroscope at ${\times40}$ magnification and photographed. After each image was scanned, the leakage area was measured at each level using Brain 3 (Nosdia Tech., Korea) software. Leakage ratio was calculated for each group and was analyzed statistically to come up with the following results: 1. At 1mm level, the Quick Obturation system had the largest amount of apical leakage and it was statistically significant when compared with the lateral condensation group and the Thermafil group (p<0.05). 2. At 2mm and 3mm level, there were no significant difference of apical leakage among all four groups (p>0.05), and from 4mm level, no apical dye penetration was observed in all the groups. In conclusion, the apical seal produced by Easy Filling system and the Quick Obturation system was comparable to lateral condensation technique and Thermafil system except for the 1mm level. More improvement of the apical seal can be expected as the operator becomes skillful with the new techniques.

• Restorative Dentistry and Endodontics
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• v.23 no.1
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• pp.346-356
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• 1998

The purpose of this study was to evaluate the sealing ability of various canal filling methods. Palatal roots of ninety extracted human maxillary molar teeth were resected at cementoenamel junction. Eighty of them were randomly assigned to four experimental groups, ten were served as positive and negative controls. All canals were prepared to # 40 using Profile. Experimental groups were obturated by lateral condensation technique, Thermafil technique, Continuous Wave of Condensation Technique, and down-pack & back-fill technique of Obtura-II, each with root canal sealer. Control groups were not obturated. Teeth were immersed in resorcinol-formaldehyde resin for 5 days at $4^{\circ}C$, and the resin was allowed to polymerize completely for 4 days at room temperature. Teeth were then ground horizontally at 1.5mm(level 1), 2.5mm(level 2), 3.5 mm(level 3) from the anatomical apex and examined with a stereomicroscope at ${\times}40$ magnification. The gap between the canal wall and the filling material, which was filled with the resin, was measured at each of the three levels. Each ratio of leakage was obtained by calculating the ratio of the area of the resin to the total area of the canal and was analyzed statistically (Rank-sum test). The results were as follows : 1. At the level 1, there was the greatest leakage in the Thermafil group and Obtura-II group, and the difference between the Obtura-II group and Continuous Wave of Condensation Technique group was statistically significant(p<0.05). 2. At the level 2, there was the least leakage in the Continuous Wave of Condensation Technique group, but there was no statistically significant difference between each group (p>0.05). 3. At the level 3, there was no statistically significant difference between each group(p>0.05).

• Journal of Periodontal and Implant Science
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• v.29 no.3
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• pp.561-578
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• 1999

The goal of periodontal therapy is the periodontal regeneration by the removal of microorganisms and their toxic products from the periodontally diseased root surface. To achieve periodontal regeneration, root conditioning as an adjunct to root planing has been done. There are low pH etchants such as citric acid, tetracycline-HCl, and EDTA solution which is a neutral chelating agent. The purpose of present study was to examine the effect of root conditioning by citric acid, tetracycline HCl, and EDTA. Total 35 root specimens(6${\times}$3${\times}$2mm) were prepared from the periodontally diseased teeth, scaled and root planed. The specimens were treated with normal saline for 1 minute, saturated citric acid(pH 1) for 3 minutes, 50mg/ml tetracycline-HCl(pH 2) for 5 minutes, 15% EDTA(pH 7) for 5 minutes using rubbing technique. The specimens were examined under scanning electron microscopy at 1000, and 3000 magnification. On the microphotographs taken at 1000 magnification, the numbers of opened and patent dentinal tubules per unit area(10,640${\mu}m^2$) were counted. And the diameters of opened dentinal tubules per unit are (10,640${\mu}m^2$) were measured. The differences of number and diameter among all groups were statistically analyzed by Kruskal Wallis Test. The results were as follows; 1. In the specimens applied with normal saline(control group), the root surface was finely cracked, and was covered by irregular smear layer. Neither exposed dentinal tubules nor any patent dentinal tubules could be seen. 2. In the specimens applied with saturated citric acid(experimental 1 group), the globular collagen fibers were exposed around the peritubular space, and many dentinal tubules were revealed. 3. In the specimens applied with tetracycline-HCl(experimental 2 group), the process-like collagen fibers were exposed around the peritubular space, and some dentinal tubules were revealed. 4. In the specimens applied with 15% EDTA(experimental 3 group), the root surface was covered by the collagenous fibrillar network, and many dentinal tubules were revealed. 5. The numbers of opened and patent dentinal tubules were significantly more in exp. 1 group and exp. 3 group than in exp. 2 group(P<0.05). But there was no significant difference between exp. 1 group and exp. 3 group. In control group, the number of opened and patent dentinal tubules could not be counted because any dentinal tubules couldn't be seen. 6 . The diameter of opened dentinal tubules was significantly smaller in exp. 1 group and exp. 3 group than in exp. 2 group(P<0.05). But there was no significant difference between exp. 1 group and exp. 3 group. In control group, the diameter of opened dentinal tubules could not be measured because any dentinal tubules couldn't be seen. The results demonstrate that root conditioning with citric acid, tetracycline- HCl, and EDTA is more effective in periodontal healing than only root planing, and 15% EDTA solution can replace low pH etching agents such as citric acid, tetracycline-HCl for root conditioning.

• Restorative Dentistry and Endodontics
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• v.27 no.4
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• pp.411-420
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• 2002

The aim of this study is to compare the adaptability of thermoplasticized injectable gutta-percha technique to the canal walls in ribbon-shaped canals. Thirty resin models simulated ribbon-shape canals were instrumented to #40 using .06 taper Profile systems. Three groups of each 10 resin models were obturated by the lateral condensation technique(LC) and the two thermoplasticized injectable gutta-percha technique; Ultrafil Endoset+Obtura II(EO) and Ultrafil Firmset(UF), respectively. After resin model were kept at room temperature for 4 days, they were resected horizontally with micro-tome at 1, 2, 3, 4 and 5mm levels from apex. At each levels. image of resected surface were taken using CCD camera under a stereomicroscope at $\times$40 magnification and stored. Ratio of the area of gutta-percha was obtained by calculating area of gutta-percha cone to the total area of canal using digitized image-ana-Iyzing program. The data were collected then analyzed statistically using One-way ANOVA. The results were as follows. 1 At 1mm levels, there was no statistically significant difference in the mean ratio of gutta-percha among the groups. 2. At 2mm level, EO showed the highest mean ratio of gutta-percha (p<0.05) and there was no significant difference between LC and UF. 3. At 3, 4, 5mm levels, EO and UF had significantly greater mean ratio of gutta-percha than LC(p<0.05) and there was no significant difference between EO and UF. In conclusion, the thermoplasticized injectable gutta-percha techniques demonstrated relatively favorable adaptability to canal walls than lateral condensation technique in ribbon-shaped canals except for 1mm level.

• Archives of Plastic Surgery
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• v.32 no.4
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• pp.521-528
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• 2005

The purpose of this research is to find out the degree of cartilage regeneration by inserting the atelo-collagen scaffold obtained from dermis of a calf on cartilage defect site. Dissection underneath the perichondrium by the periosteal elevator on both side of ears of six New Zealand white rabbits were made to expose the cartilage, leaving pairs of circular holes 3, 6, 9 mm width with punches. One hole was left for a control, and on the other hole atelo-collagen scaffold of the same size was transplanted. In postoperative 1, 2, 4 weeks, the tissues were dyed. The length of long axis of neocartilage was measured through an optical microscope with a 0.1 mm graduation at original magnification, ${\times}40$. In the first and second week, both group showed no sign of cartilage regeneration. In the fourth week, regeneration on marginal portions was observed on all groups and the average values of length of long axis of neocartilage according to defect size were as follows: In the cases with 3mm defect, it was $0.85{\pm}0.30mm$ in the control group, and $1.85{\pm}0.38mm$ in the graft group; in the cases with 6 mm defect, $1.33{\pm}0.58mm$ in the control group, and $2.25{\pm}0.46mm$ in the graft group; and in the cases with 9 mm defect, $2.33{\pm}0.77mm$ in the control group, and $4.47{\pm}1.39mm$ in the graft group. This means that the collagen scaffold has an influence on the regeneration of neocartilage. But the relative ratio of the length of neocartilage to cartilage defect size was not significant in the statistics.

• The Journal of Advanced Prosthodontics
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• v.4 no.4
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• pp.187-191
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• 2012

PURPOSE. The aim of the present study was to assess the effect of ascorbic acid, ethanol and acetone on microtensile bond strength between fiber posts pre-treated with hydrogen peroxide and composite resin cores. MATERIALS AND METHODS. Twenty four fiber posts were pre-treated with 24% hydrogen peroxide and divided into 4 groups as follows: G1: no treatment, as control group; G2: treatment with10% ascorbic acid solution for 5 minutes; G3: treatment with 70% ethanol solution for 5 minutes; and G4: treatment with 70% acetone solution for 5 minutes. Each fiber post was surrounded by a cylinder-shaped polyglass matrix which was subsequently filled with composite resin. Two sections from each sample were selected for microtensile test at a crosshead with speed of 0.5 mm/min. Statistical analyses were performed using one-way ANOVA and a post hoc Tukey HSD test. Fractured surfaces were observed under a stereomicroscope at ${\times}20$ magnification. The fractured surfaces of the specimens were observed and evaluated under a SEM. RESULTS. Means of microtensile bond strength values (MPa) and standard deviations in the groups were as follows: G1: $9.70{\pm}0.81$; G2: $12.62{\pm}1.80$; G3: $16.60{\pm}1.93$; and G4: $21.24{\pm}1.95$. G4 and G1 had the highest and the lowest bond strength values, respectively. A greater bond strength value was seen in G3 compared to G2. There were significant differences between all the groups (P<.001). All the failures were of the adhesive mode. CONCLUSION. Application of antioxidant agents may increase microtensile bond strength between fiber posts treated with hydrogen peroxide and composite cores. Acetone increased bond strength more than ascorbic acid and ethanol.

• Restorative Dentistry and Endodontics
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• v.24 no.2
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• pp.356-363
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• 1999

The purpose of this study was to compare the apical sealing effect of Microseal obturation technique with lateral condensation technique in 26 recently extracted single rooted teeth. The root canals were instrumented using step-back technique and obturated with laterally condensed gutta-percha or Microseal. Teeth were suspended in methylene blue dye for 2 days and then longitudinary splited. The apical microleakage and the adaptability of gutta-percha to the root canal wall were examined under a stereomicroscope at ${\times}20$ magnification. The results were as follows: 1. The mean leakage was 1.38${\pm}$1.18 mm for laterally condensed gutta-percha group, and 0.71${\pm}$0.57 mm for Microseal gutta-percha group. But there was no statistical difference between two groups. 2. In Microseal gutta-percha group, they showed no gap between the master cone and Microseal gutta-percha, and showed homogeneous mass. 3. In contrast, laterally condensed gutta-percha group showed some gaps not only between gutta-percha cones, but also between gutta-percha cones and the canal walls, and the gaps were filled with some sealer. And also this group showed some amout of sealer on the root canal walls, Within the limits of the results of this experiment, Microseal gutta-percha obturation technique demonstrated relatively favorable apical sealing effect and shorter obturation time. Thus, it is thought that this obturation technique is a acceptable method for clinical use but further studies on this matter should be conducted.

• The Journal of Korean Academy of Prosthodontics
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• v.36 no.1
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• pp.120-132
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• 1998

This stusy was to investigate the marginal fitness of porcelain-fused-to- metal crown after succesive firing cycle. Main variables were the degree of marginal curvature of labiocervical margin and the type of alloy. The exaggerated marginal curvature(EMC) was created by additional reduction at the faciocervical wall of the normallized marginal curvature (NMC)-typed ivorine tooth by using milling machine. The difference in the shape was the mid facial margin was placed 2mm apical to cemento- enamel junction in labial surface. Three types of alloy were high noble, noble, and base metal alloy. Test specimens were divided into 8 groups and each group had 8 specimens. Sixty four ceramometal crowns were made totally. Measurement stages were following degassing, opaquing. body porcelain firing, and glazing, and measuring sites were 4. (midmesial, midfacial, middistal, and midlingual). Digital, travelling measuring microscope (0.5 um precision, Olympus. Japan) was used under ${\times}250$ magnification. Within the limitation of this investigation, it was concluded as belows: 1. The pattern of marginal distortion was varied. Degassing stage was not a specific, causative stage that induce most of total marginal distortion during whole procedure fabricating a ceramometal crown. Body firing stage induced discrepancy relatively more than other firing stages. 2. The specimens that were Ni-based alloy and had EMC were distorted persistently following successive fabricating procedures. But marginal openings were decreased after glazing. 3. The release of metal grinding-induced stress was presumed as a cause that induce marginal distortion. 4. The amount of discrepancies of the labial and lingual margins were greater than that of the mesial and distal margin in the specimen that had EMC. 5. Silver-plated die was not enough to resist abrasion during repeated seating of metal copings on the die-holding device.

• The korean journal of orthodontics
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• v.43 no.4
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• pp.186-192
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• 2013

Objective: To analyze the fatigue resistance, debonding force, and failure type of fiber-reinforced composite, polyethylene ribbon-reinforced, and braided stainless steel wire lingual retainers in vitro. Methods: Roots of human mandibular central incisors were covered with silicone, mimicking the periodontal ligament, and embedded in polymethylmethacrylate. The specimens (N = 50), with two teeth each, were randomly divided into five groups (n = 10/group) according to the retainer materials: (1) Interlig (E-glass), (2) everStick Ortho (E-glass), (3) DentaPreg Splint (S2-glass), (4) Ribbond (polyethylene), and (5) Quad Cat wire (stainless steel). After the recommended adhesive procedures, the retainers were bonded to the teeth by using flowable composite resin (Tetric Flow). The teeth were subjected to 10,00,000 cyclic loads (8 Hz, 3 - 100 N, $45^{\circ}$ angle, under $37{\pm}3^{\circ}C$ water) at their incisoproximal contact, and debonding forces were measured with a universal testing machine (1 mm/min crosshead speed). Failure sites were examined under a stereomicroscope (${\times}40$ magnification). Data were analyzed by one-way analysis of variance. Results: All the specimens survived the cyclic loading. Their mean debonding forces were not significantly different (p > 0.05). The DentaPreg Splint group (80%) showed the highest incidence of complete adhesive debonding, followed by the Interlig group (60%). The everStick Ortho group (80%) presented predominantly partial adhesive debonding. The Quad Cat wire group (50%) presented overlying composite detachment. Conclusions: Cyclic loading did not cause debonding. The retainers presented similar debonding forces but different failure types. Braided stainless steel wire retainers presented the most repairable failure type.