• Journal of Dental Rehabilitation and Applied Science
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• v.28 no.1
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• pp.87-101
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• 2012

Bruxism is extensively defined as a diurnal or nocturnal parafunctional habit of tooth clenching or grinding. The etiology of bruxism may be categorized as central factors or peripheral factors and according to previous research results, central factors are assumed to be the main cause. Bruxism may cause tooth attrition, cervical abfraction, masseter hypertrophy, masseter or temporalis muscle pain, temporomandibular joint arthralgia, trismus, tooth or restoration fracture, pulpitis, trauma from occlusion and clenching in particularly may cause linea alba, buccal mucosa or tongue ridging. An oral appliance, electromyogram or polysomnogram is used as a tool for diagnosis and the American Sleep Disorders Association has proposed a clinical criteria. However the exact etiology of bruxism is yet controversial and the selection of treatment should be done with caution. When the rate of bruxism is moderate or greater and is accompanied with clinical symptoms and signs, treatment such as control of dangerous factors, use of an oral appliance, botulinum toxin injection, pharmacologic therapy and biofeedback therapy may be considered. So far, oral appliance treatment is known to be the most rational choice for bruxism treatment. For patients in need of esthetic correction of hypertrophic masseters, as well as bruxism treatment, botulinum toxin injection may be a choice.

• Journal of the korean academy of Pediatric Dentistry
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• v.29 no.1
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• pp.69-75
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• 2002

A number of techniques may be employed to reduce the discomfort of syringe or needle for dental care. The use of topical anesthesia is one such method. Topical anesthetics are applied to alleviate pain during many clinical procedures, such as injection of local infiltration anesthetics, primary tooth extraction, X-ray taking of sensitive patients, reducing gag reflex prior to impression taking. In children, placement of a rubber dam clamp, however, may cause significant discomfort for purpose of pit and fissure sealant and preventive resin restoration(PRR). A topical anesthetic would be beneficial to aid in rubber dam placement for this purpose. It has been suggested that all intra-oral topical anesthetics are equally effective on reflected mucosa, however EMLA(an acronym for eutectic mixture of local anesthetics), which was developed in the 1980s and produces surface anesthesia of skin, has been shown to be more effective than conventional topical anesthetics when used on attached gingivae. This report is topical anesthesized 4 case by EMLA cream, who showed better effect in reducing the pain of infiltration anesthesia, extraction of deciduous teeth, rubber dam clamp placement and reducing the pain of preformed crown adaptation.

• Journal of the Korean Academy of Esthetic Dentistry
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• v.25 no.1
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• pp.15-24
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• 2016

It is considered an implant failure when there is esthetic problems in the anterior area although the prosthesis function normally. In 2003, Dr. Kan et al stated that implant bone level is determined by the adjacent teeth. After that many scholars have studied how can achieve the esthetics result on adjacent teeth bone loss cases. In 2012, Dr. Takino published an article in Quintessence. He summarized previous articles and reclassified the defects from class 1 through 4. Class 1 and 2 depicts a situation where there is no bone loss on adjacent teeth. In Class 3 and 4, interproximal bone loss extends to the adjacent tooth. If one side is involved, it is Class 3. If both sides are involved, it is Class 4. The clue for esthetic implant restoration is whether bone loss extends to adjacent tooth or not. If the bone level of adjacent tooth is sound, we can easily achieve the esthetic but the bone level is not sound, the surgery will be complicated and the esthetic result will be unpredictable. So regenerative surgery for adjacent tooth is necessary for long-term maintenance. But the options and process were so complicated, the purpose of this article is to report the method simplify the surgery and gain a similar outcome.

• The Journal of Korean Academy of Prosthodontics
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• v.41 no.2
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• pp.148-159
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• 2003

Statement of problem Metal-ceramic restorations have been used extensively by dental clinicians for nearly 40 years. Strength an functional ability of metal-ceramic restorations are proved to be satisfying, However esthetics and biocompatibility of metal alloy which is used in metal-ceramic restoration is not ideal. Using pure gold as an alternative, have advantage of esthetics, biocompatibility over conventional metal alloy. But there had been little article which studied on the color effect of pure gold on fual porcelain color. Purpose The purpose of this study was to spectrophotometrically evaluate the difference between color of metal alloy(Au-Pt, Ni-Cr) and pure gold, during color masking procedure with opaque porcelain and to analyze the differences, Material and Methods Three types of metal - base metal(Ni-Cr), high gold alloy(Au-Pt), pure gold(GES) - specimen were fabricated 1cm in diameter. Four steps were established - after finishing, after pre-coditioning, after application of first opaque porcelain(0.08mm in thickness), after application of second opaque porcelain(0.15mm in thickness)- and tested color with spectrophotometer every each steps and analyzed with $CIEL^*a^*b^*$ color order system. One-Way ANOVA test was used to and out if there were significant differences between groups tested and Shaffe multiple comparison was used to identify where the differences were. Results 1. After finishing and pre-conditioning, pure gold(GES) group showed most high values in $L^*,a^*,b^*$. 2. After application of first opaque porcelain(0.08mm in thickness), after application of second opaque porcelain(0.15mm in thickness), pure gold(GES) group showed the least difference in $L^*,a^*,b^*$ values and the lowest ${\Delta}E$ value(${\Delta}E$=0.63). 3. After application of first opaque porcelain and after application of second opaque porcelain differences that were significant (P<0.05) between groups were found only in $a^*$ values. 4. Base metal alloy group showed the lowest $a^*$ value in test after application of first opaque porcelain and the highest value in test after application of first opaque porcelain Conclusion Pure gold group and high gold group showed higher $a^*$ values than base metal group when tested after 0.08mm thickness of opaque porcelain was applied and pure gold group showed much similar $L^*,a^*,b^*$ values between 0.08mm thickness and 0.15mm thickness of opaque porcelain. This meant that pure gold was more easily masked by opaque porcelain than the other two groups.

• The Journal of Korean Academy of Prosthodontics
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• v.54 no.1
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• pp.14-20
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• 2016

Purpose: The aim of this study was to know whether there is significant difference of peri-implant bone density according to the state of antagonist region. Materials and methods: 51 patients who had implant operation in Daejeon Dental Hospital of Wonkwang University participated in this study and total of 51 implants were analyzed. Implants were classified depending on opposing antagonist region, gender, age and location of jaw. The opposing antagonist region was divided into four groups; natural tooth, implant, pontic and edentulous region. Fractal analysis was performed using two periapical radiographs; one after implant placement and the other after 10 weeks following prosthetic restoration. The analysis was done by Image J. The data was statistically analyzed using one-way ANOVA and Tukey multiple comparison test. Results: The mean value of fractal difference was $0.009{\pm}0.048$ with opposing natural tooth, $0.026{\pm}0.080$ with opposing implant, $0.025{\pm}0.068$ with opposing pontic and $0.093{\pm}0.171$ with opposing edentulous area. There was a statistically significant difference in fractal value between opposing implant and opposing edentulous state. And there was no statistically significant difference according to age, gender and location of jaw. Conclusion: There was no statistically significant difference between 3 groups except opposing edentulous region and there was a statistically significant difference between opposing implant and edentulous region. And there was no statistically significant difference according to age, gender and location of jaw.

• Journal of Dental Rehabilitation and Applied Science
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• v.27 no.2
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• pp.233-245
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• 2011

With the use of computed tomography (CT), computer-aided design/computer-assisted machining (CAD/CAM) technology and internet, the implant dentistry has been evolved. The surgical templates made by CAD/CAM technology and precise installation of implants, permit restorations to be inserted immediately after implants have been placed. The advantages of CAD/CAM guided implant procedures are flapless, minimally invasive surgery and shorter surgery time. With this technique, less postoperative morbidity and delivery of prosthesis for immediate function would be possible. A patient with an edentulous maxilla and mandible received 7 implants in mandible using CAD/CAM surgical templates. Prefabricated provisional fixed prostheses were connected immediately after implant installation. Provisional prostheses were evaluated for aesthetics and function during 6 months. Definitive prostheses were fabricated. At 6 months recall appointment, patient's occlusion was slightly changed. To prevent additional adverse effect, regular check-up and occlusal adjustment would be needed.

• Journal of Dental Rehabilitation and Applied Science
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• v.32 no.4
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• pp.293-300
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• 2016

Purpose: The purpose of this study is finding proper bonding agents to be used when adding bis-acryl composite provisional materials. Materials and Methods: Three bonding agents with different chemical compositions were included in this study. Forty disk shaped specimens of bis-acryl composite provisional material were prepared and divided into 4 groups according to the bonding agents. Control group didn't have bonding agent. Through the Teflon mould with 4.0 mm diameter hole with 4.0 mm thickness the same bis-acryl composite provisional material was added on the disks after the surface of each specimen was treated with designated bonding agent according to the manufacturer's instructions. Shear bond test was performed and the fractured surfaces were inspected with a microscope. One-way analysis of variance was conducted and the result was further analysed with Turkey post hoc test at the significance level of 0.05. Results: The highest strength was acquired from the specimens bonded with chemical cure system and it was statistically significant (P < 0.05). This group showed 100% cohesive failures. The lowest bonding strength was recorded from the specimens used conventional light cure bonding agent, and this group's result was similar with the control group. The group used a light cure bonding agent claiming improved compatibility revealed significantly higher bond strength to the traditional light cure bonding agent group in a statistically significant way (P = 0.043). Conclusion: According to the bonding agent used the shear bond strength was significantly affected. Therefore the choice of proper bonding agent is important when hiring a bonding agent to add bis-acryl composite provisional materials.

• Restorative Dentistry and Endodontics
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• v.36 no.2
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• pp.119-124
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• 2011

Objectives: The purpose of this experiment was to evaluate four different polishing systems of their polishability and polishing time. Materials and Methods: 4 mm diameter and 2 mm thickness Teflon mold was made. Z-250 (3M ESPE) hybrid composite resin was slightly overfilled and pressed with slide glass and cured with Optilux 501 for 40 sec each side. Then the surface roughness (glass pressed: control group) was measured with profilometer. One surface of the specimen was roughened by #320 grit sand paper and polished with one of the following polishing systems; Sof-Lex (3M ESPE), Jiffy (Ultradent), Enhance (Dentsply/Caulk), or Pogo (Dentsply/Caulk). The surface roughness and the total polishing time were measured. The results were analyzed with one-way ANOVA and Duncan's multiple range test. Results: The surface roughness was lowest in Pogo, and highest in Sof-Lex. Polishing times were shortest with Pogo, and followed by the Sof-Lex, Enhance and Jiffy. Conclusions: One-step polishing system (Pogo) is very effective to get the smooth surface in a short time, therefore it can be recommended for final polishing system of the restoration.

• Restorative Dentistry and Endodontics
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• v.35 no.6
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• pp.486-491
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• 2010

Objectives: This study examined the effect of 2% chlorhexidine on the ${\mu}TBS$ of a direct composite restoration using one-step self-etch adhesives on human dentin. Materials and Methods: Twenty-four extracted permanent molars were used. The teeth were assigned randomly to six groups (n = 10), according to the adhesive system and application of chlorhexidine. With or without the application of chlorhexidine, each adhesive system was applied to the dentin surface. After the bonding procedure, light-cure composite resin buildups were produced. The restored teeth were stored in distilled water at room temperature for 24 hours, and then cut and glued to the jig of the microtensile testing machine. A tensile load was applied until the specimen failed. The failure mode was examined using an operating microscope. The data was analyzed statistically using one-way ANOVA, Student's t-test (p < 0.05) and Scheffet's test. Results: Regardless of the application of chlorhexidine, the Clearfil $S^3$ Bond showed the highest ${\mu}TBS$, followed by G-Bond and Xeno V. Adhesive failure was the main failure mode of the dentin bonding agents tested with some samples showing cohesive failure. Conclusions: The application of 2% chlorhexidine did not affect the ${\mu}TBS$ of the resin composite to the dentin using a one-step self-etch adhesive.

• The Journal of Korean Academy of Prosthodontics
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• v.57 no.4
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• pp.448-455
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• 2019

Ameloblastoma is a benign odontogenic epithelial tumor with high recurrence rate and requires extensive resection of the surrounding tissue and reconstruction of defect site. Because of the anatomical limitation of the reconstruction site, prosthetic treatment with implants is the first recommendation. This is a case of prosthetic restoration of the reconstruction site with implant fixed prosthesis in patient who underwent mandibular resection and iliac bone reconstruction due to ameloblastoma. However 14 months after completion of implant prosthesis, adjacent natural tooth erupted unexpectedly, resulting in 1mm infra-occlusion occurred including posterior implant prosthesis and anterior natural teeth. In adults, implant infra-occlusion may occur due to residual growth after placement of the maxillary anterior implant. But this case, hypo-occlusion of molar implant and open bite of anterior natural teeth is occurred due to extrusion of adjacent tooth, is rare. Thus we report the treatment process including orthodontic treatment with intrusion of the posterior tooth, and investigate the causes of sudden, unexpected tooth extrusion.