• The Journal of Advanced Prosthodontics
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• v.8 no.6
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• pp.417-422
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• 2016

PURPOSE. The purposes of this study were to evaluate the staining resistance of CAD/CAM resin-ceramics polished with different techniques and to determine the effectiveness of the polishing techniques on resin-ceramics, comparing it with that of a glazed glass-ceramic. MATERIALS AND METHODS. Four different CAD/CAM ceramics (feldspathic ceramic: C-CEREC Blocs, (SIRONA) and three resin-ceramics: L-Lava Ultimate, (3M ESPE), E-Enamic, (VITA) and CS-CeraSmart, (GC)) and one light cure composite resin: ME-Clearfil Majesty Esthetic (Kuraray) were used. Only C samples were glazed (gl). Other restorations were divided into four groups according to the polishing technique: nonpolished control group (c), a group polished with light cure liquid polish (Biscover LV BISCO) (bb), a group polished with ceramic polishing kit (Diapol, EVE) (cd), and a group polished with composite polishing kit (Clearfil Twist Dia, Kuraray) (kc). Glazed C samples and the polished samples were further divided into four subgroups and immersed into different solutions: distilled water, tea, coffee, and fermented black carrot juice. Eight samples ($8{\times}8{\times}1mm$) were prepared for each subgroup. According to CIELab system, four color measurements were made: before immersion, immersion after 1 day, after 1 week, and after 1 month. Data were analyzed with repeated measures of ANOVA (${\alpha}=.05$). RESULTS. The highest staining resistance was found in gl samples. There was no difference among gl, kc and cd (P>.05). Staining resistance of gl was significantly higher than that of bb (P<.05). Staining resistances of E and CS were significantly higher than those of L and ME (P<.05). CONCLUSION. Ceramic and composite polishing kits can be used for resin ceramics as a counterpart of glazing procedure used for full ceramic materials. Liquid polish has limited indications for resin ceramics.

• Journal of Dental Rehabilitation and Applied Science
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• v.28 no.2
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• pp.191-200
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• 2012

The patients' demand for treatment of unesthetic anterior teeth is steadily growing. Accordingly, several treatment options such as porcelain laminate veneers(PLV) have been proposed to restore the esthetic appearance of the dentition. Porcelain laminate veneers are considered minimally invasive, but they also require removal of sound enamel. One critical step in the porcelain laminate veneer technique is the achievement of sufficient ceramic thickness, and several different strategies for tooth preparation can be found in the literature. This clinical report describes a step-by-step protocols for preparation of these restorations used with the silicone index from diagnostic wax-up and the acrylic resin mock-up. Conservative use of porcelain laminate veneers provided satisfactory esthetic outcomes and preserved sound tooth structure.

• The Korean Journal of Physiology and Pharmacology
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• v.3 no.3
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• pp.351-356
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• 1999

The present study was aimed at investigating whether the calcium current in the vascular smooth muscle (VSM) cells is altered in renal hypertension. Two-kidney, one clip (2K1C) and deoxycorticosterone acetate (DOCA)-salt hypertension were made in Sprague-Dawley rats. Rats without clipping the renal artery or implanting DOCA were used as control for 2K1C and DOCA-salt hypertension, respectively. Four weeks after clipping, systolic blood pressure was significantly higher in 2K1C rats than in control $(192{\pm}24\;and\;119{\pm}4$ mmHg, respectively, n=16 each). DOCA-salt rats also showed a higher blood pressure $(180{\pm}15$ mmHg, n=18) compared with control $(121{\pm}6$ mmHg, n=14). VSM cells were enzymatically and mechanically isolated from basilar arteries. Single relaxed VSM cells measured $5{\sim}10\;{\mu}m$ in width and $70{\sim}150\;{\mu}m$ in length were obtained. VSM cells could not be differentiated in size and shape between hypertensive and normotensive rats under light microscopy. High-threshold (L-type) calcium currents were recorded using whole-cell patch clamp technique. The amplitude of the current recorded from VSM cells was larger in 2K1C hypertension than in control. Neither the voltage-dependence of the calcium current nor the cell capacitance was significantly affected by 2K1C hypertension. By contrast, the amplitude of the calcium current was not altered in DOCA-salt hypertension. These results suggest that high-threshold calcium current of the VSM cells is altered in 2K1C hypertension, and that calcium channel may not be involved in calcium recruitment of VSM in DOCA-salt hypertension.

• The Korean Journal of Pharmacology
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• v.29 no.1
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• pp.157-163
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• 1993

Intramolecular excimer formation with the fluorescent probe 1,3-di(1-pyrenyl)propane (Py-3-Py) was used to investigate the effects of methanol, ethanol, 1-propanol, 1-butanol, 1-pentanol, 1-hexanol, 1-heptanol, 1-octanol, 1-nonanol and 1-decanol on the lateral diffusion of synaptosomal plasma membrane vesicles isolated from bovine cerebral cortex (SPMV). The n-alkanols increased the excimer to monomer fluorescence intensity ratio (I'/I) of Py-3-Py in the SPMV. In a dose-dependent manner, n-alkanols increased lateral diffusion of hydrocarbon region of bulk (inner+outer monolayers) SPMV lipid bilayers, and the potencies of n-alkanols up to l-nonanol increased with carbon chain length. It appears that the potencies in bilayer fluidization due to the lateral diffusion increase by 1 order of magnitude as the carbon chain length increases by two carbon atoms. The cut-off phenomenon was reached at 1-decanol, where further increase in hydrocarbon length resulted in a decrease in pharmacological activity.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.34 no.6
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• pp.440-448
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• 2012

Purpose: The purpose of this study was to evaluate marginal bone loss of the alveolar crest on implants with or without guided bone regeneration and variables that have influenced. Methods: The clinical evaluation were performed for survival rate and marginal bone loss of 161 endosseous implants installed with guided bone regeneration (GBR) in 83 patients from September 2009 to October 2010 in relation to sex and age of patients, position of implant, implant system, length and diameter of implant. Study group (n=42) implant with GBR procedure, control group (n=41) implant without GBR technique. Simultaneous GBR approach using resorbable membranes combined with autogenous bone graft or freeze-dried bone allograft or combination. Radiographic examinations were conducted at healing abutment connection and latest visit. Marginal bone level was measured. Results: Mean marginal bone loss was 0.73 mm in study group, 0.63 mm in control group. Implants in maxillary anterior area (1.21 mm) were statistically significant in study group (P<0.05), maxillary posterior area (0.81 mm) in control group (P<0.05). Mean marginal bone loss 1.47 mm for implants with diameter 3.4 mm, 0.83 mm for implants of control group with diameter 4.0 mm (P<0.05). Some graft materials showed an increased marginal bone loss but no statistically significant influence of sex, implant type or length. Conclusion: According to these findings, this study demonstrated the amount of marginal bone loss around implant has maintained a relative stable during follow-up periods. We conclude that implants with GBR had similar survival rate and crestal bone level compared with implants in native bone.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.33 no.1
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• pp.28-39
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• 2007

The purpose of this study is to evaluate the regenerative capacity of reconstruction in the atrophied posterior maxilla by comparing bone graft procedures and alveolar distraction osteogenesis (ADO) techniques. We performed the autogenous iliac bone graft (AGB group, 5 specimens in 3 patients), and the combination (Mixed group, 3 specimens in 3 patients) of the autogenous and deproteinized bovine bone ($Bio-Oss^{(R)}$, Geistlich Co., Switzerland) as the ratio of 2:1 in the sinus floor elevation procedures. ADO procedures using $TRACK^{(R)}$ (KLS Martin Co., Germany) were also performed to augment vertical alveolar height in atrophied posterior maxilla (ADO group, 5 specimens in 4 patients). Newly generated bone tissues were obtained with the 2.0mm diameter trephine bur (3i Co., USA) during implant fixture installation after 5-7 months. Routine histolomorphological observation, immunodot blot assay for quantitative evaluation, and immunohistochemical staining with antibodies to MMP-1, -9, -10, TIMP-1, -2, and BMP-2, -4 were all carried out. Lamellar bone formation was well shown in all specimens and new bone formations of ADO group increased than those of other procedures. In immunohistochemical staining, the strong expression of BMP-2 was shown in all specimens, and immunodot blot assay showed that bone formation is accompanied by the good induction of factors associated with angiogenesis and appeared more increased amount of osteogenic and angiogenic factors in ADO group. ADO is the most effective technique for new bone formation compared to sinus floor elevation with autogenous or mixed bone graft in the atrophied posterior maxilla. In the quantitative immunodot blot assay, the regenerated bone after ADO showed more increased products of VEGF, BMP-2, PCNA and MMP-1 than those after the other procedures, and these findings were able to be confirmed by immunohistochemical stainings.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.30 no.6
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• pp.518-528
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• 2008

Purpose: The long-term experience of using osseointegrated implants for prosthetic rehabilitation of the edentulous patients shows that high success rates can be predictably achieved. Primary implant stability has been identified to be a prerequisite to achieve osseointegration. In this study, we set up the amount of removed bone so that it differed on implant installation site for each group. The influence of each initial stability on secondary stability and osseointegration was compared with time lapse using resonance frequency analysis and histomorphometric analysis. Materials and methods: A total 27 US $II^{(R)}$ (Osstem, Korea) implants were placed in the mandibular edentulous area of 3 beagle dogs. The implant site was prepared by the conventional technique with drills, and three experimental groups were divided into under-drilling group, normal-drilling group and over-drilling group. The Implant Stability Quotient (ISQ) was measured at intervals of immediately, 4, 8, 12 weeks after placement using $Osstell^{(R)}$ mentor RFA. After the animals were sacrificed, histomorphometric evaluation was executed for measuring BIC and BD. Results: 1) The under-drilled group showed most high ISQ value for whole experiment period. 2) Bone-to-implant-contact(BIC) showed the tendency to be increased gradually as the experiment period passed except the 8 weeks of the normal group. 3) The under-drilled group showed most high bone density(BD) level for whole experiment period, and it was expressed the aspect to be increased gradually according to an experiment period passage in the average of all group. 4) Resonance frequency analysis and histomorphometric analysis are presumed by generally proportional. Conclusions: As this research result, it seems that there are some correlation between resonance frequency analysis and histomorphometric analysis. As are accomplished osseointegration stably so that more superior at the region which the overpressure comes to add, it will be applicable method in clinical field.

• The korean journal of orthodontics
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• v.47 no.3
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• pp.176-185
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• 2017

Objective: To evaluate the relationship of gingival thickness (GT) and the width of keratinized gingiva (WKG) with different malocclusion groups and the level of crowding. Methods: A total of 187 periodontally healthy subjects (121 females and 66 males) who presented at the Faculty of Dentistry in $Y{\ddot{u}}z{\ddot{u}}nc{\ddot{u}}$ Yil University for orthodontic treatment were enrolled in the study. The individuals involved in the study were divided into three groups; Angle Class I malocclusion, Angle Class II malocclusion, and Angle Class III malocclusion. Each group was classified as mild, moderate, or severe according to the level of crowding. WKG was determined as the distance between the mucogingival junction and the free gingival margin. GT was determined by the transgingival probing technique. Factorial variance analysis and the Duncan multiple comparison test were employed to identify the extent to which a difference was apparent between the groups according to these parameters. Results: It was determined that teeth in the mandibular anterior region display the thin gingival biotype. WKG and GT were observed as being higher at the mandibular incisor teeth in the severe crowding group and at the mandibular canine teeth in the mild crowding group. The GT of the mandibular right central and lateral incisors was found to be thinner in the Angle Class III group. Conclusions: Within the limits of this study, the results demonstrate that, there is no significant relationship of WKG and the mean GT in the mandibular anterior region according to the Angle classification.

• Imaging Science in Dentistry
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• v.46 no.1
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• pp.63-68
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• 2016

Panoramic radiographs are a relatively simple technique that is commonly used in all dental specialties. In panoramic radiographs, in addition to the formation of real images of metal objects, ghost images may also form, and these ghost images can hinder an accurate diagnosis and interfere with the accuracy of radiology reports. Dentists must understand the formation of these images in order to avoid making incorrect radiographic diagnoses. Therefore, the present study sought to present a study of the formation of panoramic radiograph ghost images caused by metal objects in the head and neck region of a dry skull, as well as to report a clinical case in order to warn dentists about ghost images and to raise awareness thereof. An understanding of the principles of the formation of ghost images in panoramic radiographs helps prevent incorrect diagnoses.

• The Journal of Advanced Prosthodontics
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• v.1 no.1
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• pp.26-30
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• 2009

STATEMENT OF PROBLEM. Qualitative and semi-quantitative methods have been developed for TMJ sound classification, but the criteria presented are completely inhomogeneous. Thus, to develop more objective criteria for defining TMJ sounds, electroacoustical systems have been developed. We used Joint vibration analysis in the BioPAK system(Bioresearch Inc., Milwaukee, USA) as the electrovibratography. PURPOSE. The aim of this study was to examine the TMJ sounds with repect to frequency spectra patterns and the integral > 300 Hz /< 300 Hz ratios via six-months follow-up. MATERIAL AND METHODS. This study was done before and after the six-months recordings with 20 dental school students showed anterior disk displacement with reduction. Joint vibrations were analyzed using a mathematical technique known as the Fast Fourier Transform. RESULTS. In this study Group I and Group II showed varied integral > 300 /< 300 ratios before and after the six-months recordings. Also, by the comparative study between the integral > 300 /< 300 ratios and the frequency spectrums, it was conceivable that the frequency spectrums showed similar patterns at the same location that the joint sound occurred before and after the six-months recordings. while the frequency spectrums showed varied patterns at the different locations that the joint sound occurred before and after six-month recordings, it would possibly be due to the differences in the degree of internal derangement and/or in the shape of the disc. CONCLUSIONS. It is suggested that clinicians consider the integral > 300 /< 300 ratios as well as the frequency spectrums to decide the starting-point of the treatment for TMJ sounds.