Hyuck-Moon Kwon

Effect of Intravascular Ultrasound–Guided vs Angiography-Guided Everolimus-Eluting Stent Implantation: The IVUS-XPL Randomized Clinical Trial

IMPORTANCE Use of intravascular ultrasound (IVUS) promotes better clinical outcomes for coronary intervention in complex coronary lesions. However, randomized data demonstrating the clinical usefulness of IVUS are limited for lesions treated with drug-eluting stents. OBJECTIVE To determine whether the long-term clinical outcomes with IVUS-guided drug-eluting stent implantation are superior to those with angiography-guided implantation in patients with long coronary lesions. DESIGN, SETTING, AND PARTICIPANTS The Impact of Intravascular Ultrasound Guidance on Outcomes of Xience Prime Stents in Long Lesions (IVUS-XPL) randomized, multicenter trial was conducted in 1400 patients with long coronary lesions (implanted stent ≥28 mm in length) between October 2010 and July 2014 at 20 centers in Korea. INTERVENTIONS Patients were randomly assigned to receive IVUS-guided (n = 700) or angiography-guided (n = 700) everolimus-eluting stent implantation. MAIN OUTCOMES AND MEASURES Primary outcome measure was the composite of major adverse cardiac events, including cardiac death, target lesion-related myocardial infarction, or ischemia-driven target lesion revascularization at 1 year, analyzed by intention-to-treat. RESULTS One-year follow-up was complete in 1323 patients (94.5%). Major adverse cardiac events at 1 year occurred in 19 patients (2.9%) undergoing IVUS-guided and in 39 patients (5.8%) undergoing angiography-guided stent implantation (absolute difference, -2.97% [95% CI, -5.14% to -0.79%]) (hazard ratio [HR], 0.48 [95% CI, 0.28 to 0.83], P = .007). The difference was driven by a lower risk of ischemia-driven target lesion revascularization in patients undergoing IVUS-guided (17 [2.5%]) compared with angiography-guided (33 [5.0%]) stent implantation (HR, 0.51 [95% CI, 0.28 to 0.91], P = .02). Cardiac death and target lesion-related myocardial infarction were not significantly different between the 2 groups. For cardiac death, there were 3 patients (0.4%) in the IVUS-guided group and 5 patients (0.7%) in the angiography-guided group (HR, 0.60 [95% CI, 0.14 to 2.52], P = .48). Target lesion-related myocardial infarction occurred in 1 patient (0.1%) in the angiography-guided stent implantation group (P = .32). CONCLUSIONS AND RELEVANCE Among patients requiring long coronary stent implantation, the use of IVUS-guided everolimus-eluting stent implantation, compared with angiography-guided stent implantation, resulted in a significantly lower rate of the composite of major adverse cardiac events at 1 year. These differences were primarily due to lower risk of target lesion revascularization. TRIAL REGISTRATION clinicaltrials.gov Identifier: NCT01308281.

Effect of dentinal tubule occlusion by dentifrice containing nano-carbonate apatite.

This study evaluated the effects of the short-term use of a dentifrice containing nano-sized carbonate apatite (n-CAP) on the occlusion of the dentinal tubules using a scanning electron microscope (SEM) and an image analyser in vitro. One hundred human dentine specimens were wet ground with a silicone carbide papers and etched with 6% citric acid for 1 min to allow complete opening of the dentinal tubule. Specimens showing complete opening tubules were used as the baseline. The specimens were divided randomly into five groups: G1: 0% n-CAP, G2: 5% n-CAP, G3: 10% n-CAP, G4: 20% n-CAP and G5: 10%strontium chloride (SrCl(2)). Five specimens from each group were brushed by applying 50, 100, 250 and 500 strokes, respectively. All the specimens were evaluated by a SEM (x3000), and the degree of occlusion of the dentinal tubules was quantified using an image analyser. The results were analysed by one-way anova and a Tukeys test using the spss 12.0 statistical package program. The dentifrice containing 20% n-CAP for 50 strokes, which indicated 2-day use, showed the highest tubular occlusion than the other groups (P < 0.05). Moreover, this group showed 79.5% and 77.4% less open tubular area than the baseline and 0% n-CAP group, respectively. The groups containing various concentrations of n-CAP showed significant differences in the SrCl(2) group after tooth-brushing for 500 strokes, which indicated 17-day use. According to this examination of the short-term use of desensitizing dentifrices in vitro, the dentifrice containing 20% n-CAP was the most effective in occluding the dentinal tubules.

Dental caries and salivary immunoglobulin A in Down syndrome children

Objectives:  This study investigated the relationship between dental caries and the salivary Streptococcus mutans specific antibodies in Down syndrome children.

The addition of nano-sized hydroxyapatite to a sports drink to inhibit dental erosion—In vitro study using bovine enamel

OBJECTIVES This study examined the dental erosion and demineralization potential of a sports drink containing nano-sized hydroxyapatite (nano-HA) as an additive. METHODS The experimental solutions were Powerade (PA) alone and PA with 0.05%, 0.10%, and 0.25% nano-HA. The pH, titratable acidity, and calcium and phosphate content of each solution were analysed, and the degree of saturation with respect to the dental enamel (DS(En)) was obtained. Twelve sound bovine enamel specimens for each group were treated in accordance with the pH-cycling schedule which had 60min treatment with experimental solution per day for 7 days. The erosion potential was determined from the changes in surface micro hardness (SMH), the depths of erosion and demineralized layer using confocal laser scanning microscopy (CLSM), and the morphological changes to the tooth surface were examined with scanning electron microscopy (SEM) after pH-cycling. RESULTS pH and DS(En) increased with increasing nano-HA concentration in the drinks, whereas the titratable acidity decreased. There were significant differences in the SMH between the PA alone and >0.10% nano-HA groups (p<0.001). Although the PA alone group showed a pronounced erosion depth, CLSM showed no erosion depth in 0.25% nano-HA group. SEM showed an intact surface with increasing nano-HA concentration in the drinks. In conclusion, dental erosion was effectively prevented with increase of adding concentration of nano-HA, and a sports drink containing 0.25% nano-HA might prevent dental erosion.

Subjective food intake ability in relation to maximal bite force among Korean adults.

This study examined the relationship between the subjective food intake of 30 food types and their objective bite force to identify the key food items within the 30 food types to achieve a greater depth of masticatory function in Korean adults. A sample of 308 (112 males and 196 females) adults over the age of 20 (average age, 48.6) was selected among patients who visited four dental hospitals in Seoul, Korea. The subjective masticatory ability was evaluated through an interview with food intake ability questionnaires consisting of 30 food types ranging from hard to soft using a five-step Likert scale. The objective maximal bite force was measured using pressure-sensitive films. The relationship between the food intake ability and bite force was analysed and stratified according to age, gender, number of post-canine teeth lost and several clinical oral health indicators. The key foods were selected using correlation and factor analysis. The subjective food intake ability between the 30 foods and key foods were tested by cluster and one-way anova analysis. The Pearsons correlation coefficient between food intake ability and bite force was 0.45 (P < 0.01). The five key food items selected were dried cuttlefish, raw carrot, dried peanut, cubed white radish kimchi and caramel. The correlation coefficient between the food intake ability and bite force of these items was 0.51 (P < 0.01). These results suggest that the subjective food intake ability using the 30 and five key foods can be used to evaluate the masticatory function in Korean adults.

Adjunctive cilostazol versus double-dose clopidogrel after drug-eluting stent implantation: the HOST-ASSURE randomized trial (Harmonizing Optimal Strategy for Treatment of Coronary Artery Stenosis-Safety & Effectiveness of Drug-Eluting Stents & Anti-platelet Regimen).

OBJECTIVES This study sought to test the noninferiority of triple antiplatelet therapy (TAT) versus double-dose clopidogrel dual antiplatelet therapy (DDAT) in patients undergoing percutaneous coronary intervention (PCI). BACKGROUND Antiplatelet regimen is an integral component of medical therapy after PCI. A 1-week duration of doubling the dose of clopidogrel was shown to improve outcome at 1 month compared with the conventional dose in patients with acute coronary syndrome undergoing PCI. Yet in Asia, the addition of cilostazol is used more commonly than DDAT in high-risk patients. METHODS We randomly assigned 3,755 all-comers undergoing PCI to either TAT or DDAT, which was continued for 1 month, to test the noninferiority of TAT versus DDAT. The primary outcome was the cumulative incidence of net clinical outcome at 1 month post-PCI defined as the composite of cardiac death, nonfatal myocardial infarction, stent thrombosis, stroke, and PLATO (Platelet Inhibition and Patient Outcomes) major bleeding. RESULTS TAT was noninferior to DDAT with respect to the primary outcome, which occurred in 1.2% and 1.4% of patients, respectively (-0.22% absolute difference, 0.34% 1-sided 97.5% confidence interval, p = 0.0007 for noninferiority; hazard ratio: 0.85; 95% confidence interval: 0.49 to 1.48; p = 0.558 for superiority). The individual risks of cardiac death, nonfatal myocardial infarction, stent thrombosis, stroke, and PLATO major bleeding did not differ significantly between the 2 groups. There were no significant between-group differences in the treatment effect with regard to the rate of the primary outcome. CONCLUSIONS The adjunctive use of cilostazol was noninferior to doubling the dose of clopidogrel for 1 month in all-comers undergoing PCI with exclusively drug-eluting stents. (Harmonizing Optimal Strategy for Treatment of Coronary Artery Stenosis-SAfety & EffectiveneSS of Drug-ElUting Stents & Anti-platelet REgimen [HOST-ASSURE]; NCT01267734).

Effect of nano-carbonate apatite to prevent re-stain after dental bleaching in vitro.

OBJECTIVES This study examined the effect of nano-carbonate apatite (n-CAP) to prevent re-staining and the change of enamel surface after dental bleaching in vitro. METHODS Twenty-four bovine specimens were bleached for 2 weeks with 10% carbamide peroxide (CP). After bleaching, the specimens were divided into the following four groups: distilled and deionized water (DDW, negative control), 10% n-CAP, NaF (positive control) and casein phosphopeptide-amorphous calcium phosphate (CPP-ACP, positive control). Each group was subjected to pH cycling for 7 days. The specimens were treated for 4 min 3 times per day and re-staining was induced naturally by artificial saliva in the remineralization process. After pH cycling, the changes in colour were evaluated with spectrophotometry and scanning electron microscopy (SEM). The difference in colour between before and after pH cycling was evaluated using an ANOVA and Tukey test. RESULTS After pH cycling, the colour difference of n-CAP group was significantly lower than that of the DDW and CPP-ACP groups (p<0.05). SEM showed that n-CAP particles were deposited regularly on the damaged surface compared to the other groups. CONCLUSION 10% n-CAP could significantly maintain the initial colour and protect the damaged enamel structure after bleaching.

Application of fluoride iontophoresis to improve remineralization.

Iontophoresis is generally used to maximize the therapeutic action of drugs in medicine. This technique can be used to improve the remineralization effect of topical fluoride applications in dentistry. The aim of this study was to compare the remineralization effect of fluoride iontophoresis (FI) with the conventional fluoride application (CFA) method in vitro. Sixty bovine enamel specimens were divided into three groups: no fluoride treatment, CFA and FI. Fluoride was applied to the demineralized specimens for 4 min in each experimental group. The types of fluoride system used for application were 1.23% acidulated phosphate fluoride gel (12 300 p.p.m. F, pH 3.5) and 2% sodium fluoride solution (9050 p.p.m. F, pH 7) in the experimental groups. All the specimens were then placed in a remineralizing solution for 24 h. This cycle was repeated five times. An iontophoresis device (0.4 mA, 12 V) was used in the FI groups. The efficacy of this technique was evaluated by measuring changes in the surface microhardness and lesion depth of the specimens using confocal laser scanning microscope (CLSM). Data were analysed using anova and Tukeys post hoc test (P < 0.05). Although the FI groups showed higher DeltaVHN than the CFA groups, there were no significant differences between these fluoride application methods (P > 0.05). When the lesion depth was measured using CLSM imaging, there was also no significant difference between the FI and CFA groups (P > 0.05). In conclusion, FI was not significantly superior to CFA in terms of the remineralization effect.

Left atrial function assessed by Doppler echocardiography rather than left atrial volume predicts recurrence in patients with paroxysmal atrial fibrillation.

Paroxysmal atrial fibrillation (PaAF) may present as a single self‐terminating episode of atrial fibrillation (AF) or a more persistent form after sinus conversion. We investigated predictors of recurrence in patients with PaAF.

Subjective food intake ability in relation to the Mixing Ability Index in Korean adults

This study examined the association between the subjective food intake ability (FIA) using a questionnaire with 30 types of foods and the objective Mixing Ability Index (MAI) using a two-coloured wax cube. A total of 147 subjects (32 males, 115 females, mean age: 54.9 +/- 20.7) were enrolled in this study. The FIA for 30 food types and the key food intake ability (KFIA) for five key food types were obtained using a self-assessed questionnaire to evaluate the subjective chewing ability. The objective chewing ability was evaluated by asking the subjects to chew a wax cube for 10 strokes. The MAI was calculated by image analysis of the chewed wax cube. The Pearsons correlation between the subjective FIA and objective MAI was analysed according to age and number of post-canine teeth lost. The FIA for the 30 foods and five key food types showed a moderate correlation with the MAI (r = 0.51, 0.55, respectively, P < 0.01). The KFIA of the denture wearing group (r = 0.44, P < 0.01) and over 60-year-old group (r = 0.49, P < 0.01) showed a significantly higher correlation with the MAI than the other groups. In conclusion, there was a moderate correlation between the subjective FIA and objective MAI in Korean adults.