• Journal of the korean academy of Pediatric Dentistry
• /
• v.44 no.4
• /
• pp.419-426
• /
• 2017

Attachment of the orthodontic bracket conducted during the window opening procedure can result in failure due to various adverse conditions such as blood or saliva contamination, or other wet conditions. For the success of the bracket attachment, reduction of total operation time is crucial. The purpose of this literature is to evaluate the differences between the final resultant shear bond strength of the conventional method of using phosphoric acid and self-etching primer, and that of the operation time-reduced method in which the curing step is omitted subsequent to the primer application. A total of 40 human maxillary incisors were prepared. Group I(control group) and II were etched with 37% phosphoric acid and Group III and IV were conditioned with self-etching primer. Attachment of the group I and III was conducted by manufacturer's instructions. The operation time of Group II and IV was reduced by eliminating the curing step after the primer application. The resultant shear bond strength of each group was measured and an adhesive remnant index (ARI) was recorded. The mean shear bond strength of group I, II, III, and IV were 14.16 MPa, 8.33 MPa, 8.29 MPa, and 6.48 MPa respectively. Significant differences could only be found between the control group and the experimental groups (p < 0.05). The ARI indicated no significant difference among all groups.

• Journal of the korean academy of Pediatric Dentistry
• /
• v.35 no.4
• /
• pp.662-670
• /
• 2008

The purpose of this in vitro study was to evaluate the effect of fluoride containing adhesive film on prevention of enamel demineralization. Eighty bovine enamel blocks were divided randomly into 4 groups of 25: (1) APF gel applied ; (2) CavityShield$^{TM}$ applied; (3) 3% fluoride film applied; (4) 5% fluoride film applied; Early caries lesions were produced by placing each specimen into demineralization solution at pH 4.0 for 72 hours. Then lesion of the surface microhardness were measured by the Vicke's hardness test and the lesions depth were measured by polarizing light microscope. The results of the present study are as follows: 1. Difference of microhardness value ($M{\pm}SD$) between control and experimental side was the highest in group II, followed by group IV, III, I but, no significant difference was between group II, III and IV. 2. Difference of mean lesion depth ($M{\pm}SD$) between control and experimental side was the highest in group II, followed by group III, IV and I but no significant difference was between group III and IV. The results of the present study indicate that the fluoride film application is more effective than APF gel and is similar to fluoride varnish application for prevention of dental caries.

• Journal of the korean academy of Pediatric Dentistry
• /
• v.36 no.3
• /
• pp.377-384
• /
• 2009

The purpose of this study is to investigate the residual fluoride concentration of fluoride tape in oral cavity which made by spraying NaF on carboxymethylcellulose base. After 1, 3, 5, 7 hours and 1, 2, 3 days of applicating APF gel(60seconds $taste^{(R)}$, 1.23% APF gel, Group I), Fluoride varnish($CavityShield^{TM}$, 5% NaF, Group II) and Fluoride tape(SCMC-T-5, 5% NaF, Trial product, Group III) in oral cavity of 27 healthy adults in their twenties, the result of fluoride concentration in unstimulated whole saliva which measured by using fluoride sensitive electrode made up to following conclusion. 1. Until 7 hours after application in every group, it showed significantly higher fluoride concentration in saliva than baseline value but at 1, 2, 3 days after application, there were no significant differences between measurements and baseline value(p>0.05). 2. Until 7 hours after application at every time, mean fluoride concentration in saliva was higher in the order of Group II, I and III. 3. 1 hour and 3 hours after application, Group II revealed significantly higher fluoride concentration than Group III(p<0.05), but there were no significant differences between Group Ⅰ and Group III in every time.

• Journal of the Korean Arthroscopy Society
• /
• v.11 no.1
• /
• pp.13-19
• /
• 2007

Purpose: We investigated the natural history of acute, isolated posterior cruciate ligament injuries treated conservatively. Materials and Methods: Between February 1999 and October 2006, we evaluated retrospectively the results of acute, isolated posterior cruciate ligament injuries treated conservatively. The subjects consisted of 21 patients. At initial and follow up visits physical examination, $KT-2000^{TM}$ arthrometer and MRI were performed to assess improvement on the knee stability and continuity of the posterior cruciate ligament. IKDC (International Knee Documentation Committee) knee scoring and quadriceps muscle strength were also checked in all population. Comparing the results of initial and follow up examinations we assessed the natural history of acute, isolated posterior cruciate ligament injuries treated conservatively. The mean follow up period was 22.7 months. Results: The posterior drawer test showed 14 cases of Grade I, 6 cases of Grade II and 1 case of Grade III progressing 18 cases of Grade I and 3 cases of Grade II. The mean difference of 5.7mm by $KT-2000^{TM}$ arthrometer was changed Into 2.7mm and the continuity of posterior cruciate ligament initially checked by 48.1% on MRI increased to 69.7%. The mean quadriceps muscle strength was grade 'Good' and mean IKDC knee score was nearly grade 'A'. Conclusion: Our study suggests that patients with acute, isolated posterior cruciate ligament injuries treated conservatively may get good clinical outcomes on clinical situation and MRI.

• Bulletin of the Korean Chemical Society
• /
• v.32 no.10
• /
• pp.3790-3792
• /
• 2011

• Bulletin of the Korean Chemical Society
• /
• v.30 no.12
• /
• pp.3117-3119
• /
• 2009

• The KIPS Transactions:PartA
• /
• v.12A no.3 s.93
• /
• pp.215-222
• /
• 2005

The efficient utilization of cache memories is a key factor in achieving high performance for computing large signal transforms. Nonunit stride access in computation of large DFTs causes cache conflict misses, thereby resulting in poor cache performance. It leads to a severe degradation in overall performance. In this paper, we propose a dynamic data layout approach considering the memory hierarchy system. In our approach, data reorganization is performed between computation stages to reduce the number of cache misses. Also, we develop an efficient search algorithm to determine the optimal tree with the minimum execution time among possible factorization trees considering the size of DFTs and the data access stride. Our approach is applied to compute the fast Fourier Transform (FFT). Experiments were performed on Pentium 4, $Athlon^{TM}$ 64, Alpha 21264, UtraSPARC III. Experiment results show that our FFT achieve performance improvement of up to 3.37 times better than the previous FFT packages.

• Bulletin of the Korean Chemical Society
• /
• v.34 no.9
• /
• pp.2609-2615
• /
• 2013

A series of fluorene-carbazole copolymers containing the pendant phosphor chromophore $Ir(absn)_2(acac)$ (absn: 2-(1-naphthyl)benzothiazole; acac: acetylacetone) were designed and synthesized via Yamamoto coupling. In the film state, these copolymers exhibited absorption and emission peaks at approximately 389 and 426 nm, respectively, which originated from the fluorene backbone. However, in electroluminescent (EL) devices, a significantly red-shifted emission at approximately 611 nm was observed, which was attributed to the pendant iridium(III) complex. Using these copolymers as a single emission layer, polymer light-emitting devices with ITO/PEDOT:PSS/polymer:DNTPD/TmPyPb/LiF/Al configurations exhibited a saturated red emission at 611 nm. The attached iridium(III) complex had a significant effect on the EL performance. A maximum luminous efficiency of 0.85 cd/A, maximum external quantum efficiency of 0.77, maximum power efficiency of 0.48 lm/W, and maximum luminance of 883 $cd/m^2$ were achieved from a device fabricated with the copolymer containing the iridium(III) complex in a 2% molar ratio.

• Proceedings of the SCSK Conference
• /
• 2003.09b
• /
• pp.407-416
• /
• 2003

In this study, we evaluate the correlation between in vitro and in vivo determination of SPF of sunscreen products containing various ingredients depending on emulsification system. For in vitro approach, we determined SPF by the method of Diffey and Robson using an TransporeTM tape(3M Health care, USA) and SPF 290-analyzer(Optometrics Co. USA). SPF values and standard deviations are calculated and displayed after completion of the run. In vivo SPF values are determined according to KFDA (the Korea Food and Drug Administration) method in panels of Fitzpatrick's skin type II or III. We investigated the difference in SPF data of sunscreen ingredient according to emulsification system. The in vivo SPF data is high in water-in oil(W/O) emulsion than in oil-in water(O/W) emulsion samples. The difference may be due to the particular behavior in each vehicles and its presence on skin surface may produce a different sunscreen film. We obtained the corrlation coefficient between in vitro and in vivo SPF data for O/W (R-squre=0.72 )and W/O emulsion(R-squre=0.77). From these results, we suggest the improvement of methodology using Transpore$^{TM}$ tape as substrate to increase the predictability of in vitro method.d.

• Journal of Periodontal and Implant Science
• /
• v.53 no.6
• /
• pp.453-466
• /
• 2023

Purpose: This study aimed to quantify alveolar bone morphology, demonstrate the relationship between tooth angulation and alveolar bone thickness, and introduce a new classification for anterior mandibular teeth related to immediate implant placement (IIP). Methods: Cone-beam computed tomography (CBCT) images of 211 anterior mandibular teeth were analyzed in sagittal slices to measure the thickness of the facial alveolar bone crest (FAB1) and apex (FAB2), and the lingual alveolar bone crest (LAB1) and apex (LAB2). Tooth angulation was classified as 1°-10°, 11°-20°, and >20° according to the tooth's long axis and alveolar bone wall. Spearman correlation coefficients were used to evaluate correlations between the variables. Results: FAB1 and LAB1 were predominantly thin (<1 mm) (84.4% and 73.4%, respectively), with the lateral incisors being thinnest. At the apical level, FAB2 and LAB2 were thick in 99.5% and 99.1% of cases, respectively. Significant differences were documented in FAB2 (P=0.004), LAB1 (P=0.001), and LAB2 (P=0.001) of all mandibular teeth. At all apical levels of the inspected teeth, a significant negative correlation existed between TA and FAB2. Meanwhile, TA showed a significant positive correlation with LAB2 of the lateral incisors and canines. These patterns were then divided into class I (thick facial and lingual alveolar bone), class II (facially inclined teeth) with subtype A (1°-10°) and subtype B (11°-20°), and class III (lingually inclined teeth) with subtype A (1°-10°) and subtype B (11°-20°). Conclusions: Mandibular anterior teeth have predominantly thin facial and lingual crests, making the lingual bone apical thickness crucial for IIP. Although anchorage can be obtained from lingual bone, tooth angulation and tooth types had an impact on IIP planning. Hence, the new classification based on TA and alveolar bone wall may enable rational clinical planning for IIP treatment.