Clinical Dental Hygienists’ Awareness of the Medical Technicians Act and Clinical Performance in Korea / 치위생과학회지

Background@#In Korea, laws for many medical technicians were revised in the Enforcement Decree of the Medical Technicians Act (MTA), which was announced on December 2018, whereas those related to dental hygienists remained unchanged. This study aimed to determine the awareness and opinions of dental hygienists regarding MTA. @*Methods@#Dental hygienist were recruited as participants via convenient sampling in Seoul, Gyeonggi-do, and Chungcheong-do; data from 291 self-reported questionnaire responses were used for the final analysis. We investigated the participants’ general characteristics, awareness, and request for the amendment of the MTA. The compliance with the work scope specified in the MTA and level of demand for revision of the MTA were analyzed by independent t-test and one-way analysis of variance. For all statistical analyses, the significance level was set at 0.05. @*Results@#For the 2018 MTA revision, 99 (34.02%) knew that dental treatment assistance and surgery assistance were excluded, whereas 192 (65.98%) did not know. The item “The current medical technician law must be revised” was scored 4.13±0.80 out of 5 points, and significant differences were identified according to the education level, career, and position (p＜0.05). The item “It is necessary to institutionalize the expanded work scope beyond the work scope of dental hygienists specified in the MTA” was scored 4.02±1.04 out of 5 points, and significant differences were identified according to age (p＜0.05). @*Conclusion@#The participants wanted the MTA to be revised to reflect the real-world work performed by dental hygienists in the dental clinical field. The legal system must ensure the legal protection of the work area of the dental hygienist as an oral health professional, and recognize the legal work scope of the dental hygienist.

Evaluation of the Potential of Commercial Vitamin Drinks to Induce Tooth Erosion / 치위생과학회지

BACKGROUND: The market for vitamin drinks is expanding both in Korea and worldwide. However, it was difficult to find studies regarding the possibility of tooth erosion induction due to vitamin drinks. The purpose of the present in vitro study was to evaluate the effect of tooth erosion caused by a few commercial vitamin beverages on bovine teeth enamel in terms of erosion depth and fluorescence loss. METHODS: Three experimental groups (vitamin drinks), a positive control group (Coca-Cola), and a negative control group (mineral water) were established. Each group consisted of 5 specimens obtained from sound bovine teeth. The pH and titratable acidity of beverages were measured. Specimens were immersed in the beverages and artificial saliva for 6 and 18 hours, respectively. This cycle was repeated for 5 days. The depth of the tooth loss caused by tooth erosion (erosion depth) and maximum loss of fluorescence (Max ΔF) were measured using the microscope and quantified light-induced fluorescence-digital, respectively. For the statistical analysis, the Kruskal-Wallis test and ANOVA were used to compare the erosion depth and Max ΔF of the enamel surfaces. In addition, Spearman correlations were estimated. RESULTS: The pH of the three vitamin beverages ranged from 2.65 to 3.01, which is similar to that of the positive control group. All beverages, except mineral water, had sugar and acidic ingredients. Vitamin drinks and the positive control, Coca-Cola, caused tooth erosion lesions, and showed significant differences in erosion depth compared to mineral water (p<0.05). The vitamin beverages with low pH were associated with high erosion depth and Max ΔF. CONCLUSION: Vitamin drinks have the potential to cause tooth erosion.

Influence of Some Commercially Available Mouthwashes on Teeth / 치위생과학회지

The purpose of this study was to investigate the chemical properties of some commercially available mouthwashes and to ascertain whether the mouthwashes accelerated mineral loss in dental enamel. Five commercially available mouthwashes were selected from the three largest malls in Korea: Perio Total 7 Aqua Cool Mint Strong FreshTM (PS; LG Household & Health Care Ltd.), Garglin OriginalTM (Dong-A Pharmaceutical Co., Ltd.), Garglin ZeroTM (Dong-A Pharmaceutical Co., Ltd.), Listerine Naturals CitrusTM (LC; IDS Manufacturing Ltd.), and Listerine Cool MintTM (LM; IDS Manufacturing Ltd.). The composition, pH, and titratable acidity of the mouthwashes were investigated. Six bovine teeth specimens were prepared for each mouthwash group. Each of the six specimens was individually immersed in 30 ml aliquots of mouthwash for 1 minute, 30 minutes, 90 minutes, and 120 minutes, and the samples were placed in a 36.5℃ stirred incubator. The degree of mineral loss (ΔF) of the tooth surface area exposed to mouthwash, compared with normal teeth, was analyzed by quantitative light-induced fluorescence-digital. The difference in ΔF among mouthwash groups was examined by the Kruskal-Wallis H test (α=0.05). The contents of mouthwashes differed between Listerine and other products, and the pH ranged from 4.09 to 6.75. The titratable acidity of PS was the lowest at 0.63 ml and highest at 9.25 ml for LM. Minor mineral loss was observed when dental specimens were immersed in the Listerine products (LC and LM) for more than 90 minutes, but the degree of mineral loss for Listerine products was not statistically significantly different from that for groups without mineral loss. In conclusion, all five commercially available mouthwashes showed no harmful effects on tooth enamel.

Assessment of Early Dental Caries by Using Optical Coherence Tomography / 치위생과학회지

The purpose of this study was to assess the correlation between integrated mineral loss (volume % mineral×µm, ΔZ(TMR)) determined using transverse microradiography (TMR) and integrated reflectivity (dB×µm, ΔR(OCT)) determined using optical coherence tomography (OCT) for detecting early dental caries with lesion depth more than 200 µm. Sixty tooth specimens were made from sound bovine teeth. They were immersed in a demineralized solution for 20, 30, and 40 days. The ΔR(OCT) was obtained from the cross-sectional OCT image. The ΔZ(TMR) was obtained from the TMR image. The correlation between ΔR(OCT) and ΔZ(TMR) was examined using Pearson correlation. The Bland-Altman plot was constructed using the ΔR(OCT) and ΔZ(TMR) values. A significant correlation between ΔR(OCT) and ΔZ(TMR) was confirmed (r=0.491, p=0.003). Moreover, most of the difference between ΔR(OCT) and ΔZ(TMR) was included in the error section of the Bland-Altman plot. Therefore, OCT could be used as a substitute for TMR when analyzing mineral loss in early dental caries.

In vitro quantification of occlusal caries lesion using QLF-D, ICDAS, and DIAGNOdent / 대한구강보건학회지

OBJECTIVES: To compare the QLF-D method and the ICDAS and DIAGNOdent techniques for in vitro quantification of occlusal caries and to assess the histological features of the caries. METHODS: One hundred and twenty-two extracted permanent teeth were selected, and the site of interest on the occlusal surface was examined using each detection method. The occlusal sites were classified according to the ICDAS II criteria based on the decision taken by two investigators, who have taken the ICDAS E-learning course. The examined site was then measured using the DIAGNOdent, and the peak value was recorded. In addition, by using the QLF-D, the occlusal site was photographed to obtain the DeltaFmax value. After all assessments were performed, the occlusal sites were vertically sectioned in order to assess the histological features. This was considered the gold standard. The histological criteria were graded using a 4-point scale as follows: S=sound (n=21), E1=limited enamel caries (n=27), E2=caries extending to the dento-enamel junction (n=49), D=caries involving the dentine (n=25). RESULTS: An ICDAS code between 0 and 4 was assigned to all the occlusal sites, and this revealed the QLF-D value, which was between -95 to 0. The DIAGNOdent value was between 8 and 99. The correlation values of QLF-D, ICDAS, and DIAGNOdent with the histological features were 0.68, 0.58, and 0.46, respectively (P<0.01). A highly significant correlation was observed between QLF-D and the gold standard, which showed a moderate correlation and an acceptable correlation was observed with ICDAS (r=0.75, P<0.01). A statistically significant difference was observed in the average QLF-D values of each histological grade i.e., -28.5 (S), -53.7 (E1), -68.1 (E2), and -84.4 (D). CONCLUSIONS: The QLF-D showed a significant correlation with the ICDAS and histological features. Therefore, visual inspection with QLF-D would improve the detection accuracy and ensure early diagnosis of dental caries.

Modification of surface pretreatment of white spot lesions to improve the safety and efficacy of resin infiltration / 대한치과교정학회지

OBJECTIVE: A low-viscosity resin (infiltrant) was used to inhibit the progression of white spot lesions (WSLs) and resolve associated esthetic issues. An alternative pretreatment was explored to increase the pore volume of the surface layer of the WSLs. Also, the penetration effects of the infiltrant were evaluated for various pretreatments. METHODS: Sixty two artificial lesions were fabricated on bovine teeth. As a positive control, 15% HCl gel was applied for 120 seconds. Further, 37% H3PO4 gel was applied for 30 seconds using three methods. The samples were divided as follows: H3PO4 only group, H3PO4 sponge group, and H3PO4 brush group. The acid was gently rubbed with the applicators (i.e., a sponge or brush) throughout the application time. To compare the effects of resin infiltration, twenty paired halves of specimens were treated with an infiltrant (ICON(R)). RESULTS: Thicknesses of the removed surface layers and infiltrated areas were evaluated by confocal laser scanning microscope. The positive control and the 37% H3PO4 brush group failed to show significant differences in the removed thickness (p > 0.05); however, the mean percentage of the infiltrated area was higher in the 37% H3PO4 brush group (84.13 +/- 7.58%) than the positive control (63.51 +/- 7.62%, p < 0.001). Scanning electron microscope observations indicate higher pore volumes for the 37% H3PO4 brush group than for the positive control. CONCLUSIONS: Application of 37% H3PO4 with a brush for 30 seconds increased the pore volume of WSL surface layers and the percentage of infiltrated areas in comparison to the use of 15% HCl for 120 seconds.

Analysis of the erosive effects of children's beverages using a pH-cycling model / 대한구강보건학회지

OBJECTIVES: The aims of this in vitro study were (1) to assess the erosive potential of several children's beverages in comparison to cola and orange juice, by using an in vitro pH-cycling model, and (2) to investigate the factors related to dental erosion caused by the beverages. METHODS: Eight different children's beverages (Chorongi, Capri-sun, Grateful nature wisdom, I-kicker, Koal-koal koala, My friend pororo, Qoo, and Strong zzanggu), Cola, and an orange juice, which are available in the Korean market, were used. To characterize each test beverage, the pH, titratable acidity to pH 7.0, concentration of calcium and phosphorus, and degree of saturation with respect to hydroxyapatite (DS(HAP)) were analyzed. Erosive potential of the test beverages was assessed by the depth of enamel loss observed in specimens subjected to pH cycling for 8 days. This cycle consisted of exposure to each beverage for 20 min, thrice daily, and to a remineralizing solution every day. The correlation between the depth of the enamel loss and the chemical properties of the beverages was assessed by Spearman's rank correlation coefficients and multiple linear regression tests (P<0.05). RESULTS: The depth of enamel loss caused by the beverages was found to vary from 0.11 to 105.47 microm. Enamel loss with all the children's beverages tested was lesser compared to that with Cola (P<0.05) but was similar or greater than that with orange juice, except in one beverage. The pH, concentration of calcium, and DS(HAP) were significantly correlated with the depth of enamel loss (rho=-0.842, rho=-0.796, and rho=-0.867, respectively; P<0.01). Multiple regression analysis showed that pH and concentration of calcium were impact variables for the erosive potential of test beverages (P<0.05). CONCLUSIONS: The children's beverages tested had lower erosive potential than Coca Cola, but five (I-kiker, Grateful nature wisdom, Qoo, Capri-sun, and Chorongi) of them had higher erosive potential than orange juice. Moreover, among the chemical properties of beverages, significant factors affecting enamel loss were pH value and concentration of calcium.

Permanent Pacemaker Implantation in a Patient with MELAS Syndrome / 대한내과학회지

A 35-year-old male patient with heart and renal failure and pneumonia was transferred to our department due to recurrent cardiac standstill with syncope. He had been diagnosed as and treated for MELAS (mitochondrial myopathy, encephalopathy, lactic acidosis, and stroke-like episodes) syndrome for the past 3 years. Electrocardiography (ECG) showed the Wolff-Parkinson-White pattern, and an echocardiogram showed hypertrophic cardiomyopathy. He developed syncopal attacks intermittently, and ECG monitoring showed intermittent bradycardia. His Holter monitoring showed several episodes of 5-16 seconds of sinus arrest. We conducted an electrophysiological study to evaluate the arrhythmia. During atrial and ventricular extra-stimuli, cardiac standstill developed several times, and the duration of pauses varied from 2.5 to 5.5 seconds. Abrupt asystolic events also developed accompanying syncopal attacks that were not related to the extra-stimuli. We decided to implant a permanent pacemaker. The patient's syncopal episodes disappeared after implantation of a DDD type pacemaker.

Isolated Left Ventricular Noncompaction with a Congenital Aneurysm Presenting with Recurrent Embolism

Isolated left ventricular noncompaction (LVNC) is a rare disorder caused by embryonic arrest of compaction. LVNC is sometimes associated with other congenital cardiac disorders; however, there have been few reports of its coexistence with a left ventricular aneurysm. A 40-year-old woman was admitted to our hospital for renal infarction. She had a history of embolic cerebral infarction 10 years ago. Transthoracic echocardiography showed prominent trabeculae and deep intertrabecular recesses which are filled with blood from the left ventricular (LV) cavity. A thrombus in the akinetic apical wall was confirmed by contrast echocardiography. Using cardiac computed tomography and magnetic resonance imaging, we rejected a possible diagnosis of suspicion of coronary artery disease. She was diagnosed LVNC with a thrombus in apical aneurysm. Here, we report the first patient in Korea known to have LVNC accompanying LV congenital aneurysm presenting with recurrent embolism.

Appropriateness of Adenosine Deaminase-Guided Management for Patients with Pericardial Effusion / 대한내과학회지

BACKGROUND/AIMS: The prognostic impact of empirical anti-tuberculous management according to adenosine deaminase (ADA) levels in patients exhibiting pericardial effusion (PE) has not been established. We evaluated the appropriateness of ADA-guided anti-tuberculous medication for patients with PE. METHODS: From 2001 to 2010, 47 patients with PE and who were diagnosed with either tuberculous pericarditis (TbP) or idiopathic pericarditis (IP) were enrolled. The diagnosis of definite TbP was made by the presence of Tb bacilli or caseous granuloma in pericardial tissue or effusion. The diagnosis of probable TbP was made by the presence of one or more of the following: (1) elevated ADA (> or = 40 IU/L) in pericardial fluid, (2) positive Tb interferon test, or (3) extracardiac presence of Tb. All clinical information was collected by medical record review and telephone contact. RESULTS: Among the 47 patients with PE, 12 were diagnosed with definite TbP; 17, with probable TbP; and 18, with IP. The mean ADA level was significantly higher in patients with definite TbP than in patients with IP (74.97 +/- 36.79 vs. 20.14 +/- 7.39 IU/L; p < 0.001). The optimal ADA cutoff value for diagnosis of definite TbP was 64 IU/L. The median follow-up time was 12.1 months (range, 0.17-100 months). In patients with low levels of ADA (< 40 IU/L), the incidence of death or recurrence did not different between patients who were prescribed anti-tuberculous medication and those who were not. CONCLUSIONS: The ADA level in pericardial fluid was useful for making a rapid diagnosis of tuberculous pericarditis. Even in tuberculosis-endemic areas, patients with ADA < 40 IU/L may have a good prognosis without empirical anti-tuberculous treatment.

Rupture and Spontaneous Sealing of a Coronary Aneurysm After Deployment of Drug-Eluting Stent

Lesions with coronary artery aneurysm (CAA) can become complicated during percutaneous coronary intervention. Here, we report a case of a 78-year-old man who developed a rupture, and spontaneous sealing of the CAA occurred after stent implantation, as shown by computed tomography coronary angiography.

The effects of ipriflavone on the periodontal reorganization following experimental tooth movement in the rat / 대한치과교정학회지

OBJECTIVE: The purpose of this study was to examine the effect of ipriflavone on periodontal reorganization and prevention of relapse following tooth movement. METHODS: Orthodontic rubber bands were inserted between the first and second maxillary molars of 27 white male rats for 3 weeks for experimental tooth movement. From one day before the removal of orthodontic rubber band, ipriflavone was administered 50 or 400 mg/kg daily in each experimental group whereas carboxymethyl cellulose solution was administered in the control group. They were sacrificed at the 5, 10, and 15th day from the day of removal of orthodontic rubber bands. The amount of relapse was evaluated by measuring the interdental space, and the extent of periodontal reorganization was compared through histological examination. RESULTS: In case of ipriflavone administration, the amount and velocity of relapse was less and slower compared to the control group. In addition, the ipriflavone group showed more rapid periodontal reorganization compared to the control group. CONCLUSIONS: The results of the present study suggest that ipriflavone administration can be used effectively in the prevention of relapse following orthodontic tooth movement through the acceleration of periodontal reorganization.

Change of shear bond strength of orthodontic brackets acording to surface treatment on dental gold alloy / 대한치과교정학회지

The dental gold alloy shows a lower bond strength than the natural teeth in bracket bonding, and this can be a possible source of subsequent bond failure. This study aims to evaluate the effect of various gold alloy surface treatment techniques on shear bond strength between the orthodontic adhesives and the gold alloy and to find ways of increasing the bond strength. Two hundred and forty specimens made of the dental gold alloy were divided into twelve groups based on the combination of surface treatment methods(non-surface treatment, sandblasted, sandblasted plus tin-plated, and sandblasted plus intermediate adhesive) and adhesive systems (Ortho-one, Panavia 21, Superbond C&B). The specimens with bonded brackets were placed in distilled water at 37degrees C for 24 hours and shear bond strength was measured by a universal testing machine. The results were as follows: 1. All surface-treated groups showed a significantly higher shear bond strength than non-surface-treated groups. 2. The sandblasted plus tin-plated grout showed a significantly higher shear bond strength than the sandblasted group only when Panavia 21 was involved. 3. The sandblasted plus intermediate adhesive group showed a significantly higher shear bond strength than sandblasted group regardless of the type of adhesive used. 4. Of.the three resin adhesive types, the Superbond C&B showed the highest bond strength, followed by Panavia 21 and Ortho-one. These findings suggest that a combination of sandblasting and intermediate resin treatment is desirable in order to enhance bracket bond strength regardless of adhesive types.