Comparison of Cariogenic Characteristics between Fluoride-sensitive and Fluoride-resistant Streptococcus mutans / 대한소아치과학회지

The aim of this study is to compare cariogenic characteristics of fluoride-sensitive Streptococcus mutans [fluoride-sensitive (FS) S. mutans ] and fluoride-resistant Streptococcus mutans [fluoride-resistant (FR) S. mutans] in the presence of sucrose, and to evaluate its effect on cariogenic biofilm formation. S. mutans ATCC 25175 was continuously cultured in trypticase soy broth (TSB) containing NaF (70 ppm) for 40 days to generate FR S. mutans . FS and FR S. mutans were inoculated in TSB with or without 2% sucrose, and optical density and pH were measured every hour. An oral biofilm was formed using saliva bacteria and analyzed through confocal laser scanning microscopy and CFU count. Finally, the expression of glucosyltransferases genes of both S. mutans was investigated through RT-PCR. FR S. mutans exhibited slower growth and lower acidogenicity in the presence of sucrose compared to FS S. mutans . Both cariogenic and single species biofilm formation was lower in the presence of FR S. mutans , along with reduced number of bacteria. FR S. mutans showed significantly low levels of gtfB, gtfC, and gtfD expression compared to FS S. mutans . On the basis of results, FR S. mutans may be less virulent in the induction of dental caries.

Fracture Strength and Translucency of CAD/CAM Zirconia Crown for Primary Anterior Tooth / 대한소아치과학회지

The purpose of this study is to evaluate the validity of primary anterior zirconia crown made with Computer Aided Design/Computer Aided Manufacturing (CAD/CAM) technology by analyzing fracture strength and translucency parameter.Zirconia crown was designed with CAD software, using 3D scanned data of #61 tooth model. Crown fabrication was performed with CAM machine using zirconia block. Zirconia crowns were divided into 3 groups according to thickness(0.3, 0.5, and 0.7 mm), and fracture strength was compared with 1.0 mm thickness of resin strip crown. The compressive force was applied with universal testing machine at 30° along the incisal edge at increments of 1 mm/min. For translucency evaluation, 0.3, 0.5, and 0.7 mm thickness of zirconia specimens were fabricated and translucency was measured with spectrophotometer.Among zirconia groups, there was a significant increase in fracture strength as thickness increased (p Thin primary anterior zirconia crown can be designed and fabricated according to individual needs by using CAD/CAM. Restoration with thin crown would reduce the amount of tooth reduction, risk of pulp exposure, and make more esthetic restoration possible.

Effects of fluoride release and solubility of resin modified glass ionomer with surface coating agents

PURPOSE: This study aimed to investigate the correlation between the solubility and the amount of fluoride release when a resin surface coating agent is applied to RMGIC. MATERIALS AND METHODS: To measure the fluoride release and solubility, Fuji II LC®and Filtek™ Z350XT without a surface coating, Fuji II LC® with G coat plus™ and Fuji II LC® with Permaseal® were prepared. And the amount of fluoride release and solubility were measured. RESULTS: There was no significant difference in the daily fluoride release between the surface coating agents. The cumulative fluoride release was significantly different between the groups using RMGIC at 56 days (P < 0.05). In the solubility measurement, RMGIC without surface coating was significantly different only on the 7th day compared to the other three groups (P < 0.05). CONCLUSION: Surface coating agents can prevent the degradation of properties by the initial solvent in RMGIC. Therefore, fluoride is preserved inside the restorative material and the effect of surface coating after the addition is reduced, so that the effect on fluoride release and storage is also reduced.

Correlation between Fluoride Release, Microhardness and Solubility of High viscosity Glass Ionomers / 대한소아치과학회지

This study was to measure and compare the amount of fluoride, microhardness and solubility of high viscosity glass ionomer and resin-reinforced glass ionomer during 84 days.Fuji IX GP EXTRA, Fuji IX GP, Fuji II LC and Filtek™ Z350XT stored in deionized water for 84 days to measure fluoride release, microhardness and solubility.As a result of measurement of fluoride release, all the glass ionomers showed the highest amount of fluoride release on day 1 and gradually decreased. Fuji IX GP EXTRA showed the highest amount of fluoride release and cumulative release. And Fuji IX GP and Fuji II LC showed no significant difference. Microhardness measurements showed that all experimental groups decreased 1 day after exposure to water. After 84 days, microhardness showed no significant difference between Fuji IX GP EXTRA and Fuji IX GP, and Fuji II LC was the lowest. In the solubility measurement, Fuji IX GP EXTRA, Fuji IX GP, and Fuji II LC increased rapidly to 21 days. After 21 days, there was no significant difference in the three groups. As a result, short term fluoride release affects solubility and microhardness, but long term fluoride release has no correlation.Through this study, the amount of fluoride, microhardness, and solubility of various glass ionomers were evaluated, and these properties could be applied clinically.

Cariogenicity of Vitamin Supplements for Children / 대한소아치과학회지

The purpose of this study is to analyze the cariogenicity of vitamin supplements for children by the Caries Potentiality Index (CPI), pH drop capacity, proliferation rate of Streptococcus mutans.Four vitamin supplements were selected - Noma (NM), Cenovis Kids (CK), Animal Parade (AP), and Character Vitamin (CV).CPI value decreased in the order of AP, CV, CK, and NM. Initial values of all experimental groups showed acidity below pH 7.0. Analysis of the colony forming units of Streptococcus mutans showed that NM and CV resulted a higher proliferation rate (p < 0.05) than CK and AP (p < 0.05). Bacterial activity of the control group was lower than other groups when observed with a confocal laser scanning microscope.Considering the bacterial activity and acidity of vitamin supplements, it is necessary to pay close attention when children taken the vitamin supplements for their oral health.

A survey of the intravenous sedation status in one provincial dental clinic center for the disabled in Korea

BACKGROUND: The objective of the present study was to examine the status of patients who had received dental treatment under intravenous (IV) sedation at Chungnam Dental Clinic for the Disabled in Korea from its inception to the present time, and to review the analysis results. METHODS: Retrospective analysis was performed on 305 cases of patients who had received dental treatments under IV sedation between January 2011 and May 2016. The analysis examined the patient's sex, age, primary reason for IV sedation, duration of anesthesia and dental treatment, type of dental treatment performed, number of clinical departments involved in the dental treatment and level of multidisciplinary cooperation, and annual trends. RESULTS: Most dental treatments using intravenous sedation were performed on medically disabled patients or dentally disabled patients with an extreme gag reflex or dental phobia. The mean duration of IV sedation was 72.5 min, while the mean duration of treatment was 58.0 min. The types of dental treatments included surgical treatment (n = 209), periodontal treatment (n = 28), prosthodontic treatment (n = 28), restorative treatment (n = 23), implant surgery (n = 22), endodontic treatment (n = 9), reduction of temporomandibular joint dislocation (n = 1), and treatment of traumatic injuries (n = 1), with treatments mostly performed on adult patients. CONCLUSIONS: With increasing demand for minimally painful treatment, cases using IV sedation are on an upward trend and are expected to continue to increase.

A survey of the intravenous sedation status in one provincial dental clinic center for the disabled in Korea

BACKGROUND: The objective of the present study was to examine the status of patients who had received dental treatment under intravenous (IV) sedation at Chungnam Dental Clinic for the Disabled in Korea from its inception to the present time, and to review the analysis results. METHODS: Retrospective analysis was performed on 305 cases of patients who had received dental treatments under IV sedation between January 2011 and May 2016. The analysis examined the patient's sex, age, primary reason for IV sedation, duration of anesthesia and dental treatment, type of dental treatment performed, number of clinical departments involved in the dental treatment and level of multidisciplinary cooperation, and annual trends. RESULTS: Most dental treatments using intravenous sedation were performed on medically disabled patients or dentally disabled patients with an extreme gag reflex or dental phobia. The mean duration of IV sedation was 72.5 min, while the mean duration of treatment was 58.0 min. The types of dental treatments included surgical treatment (n = 209), periodontal treatment (n = 28), prosthodontic treatment (n = 28), restorative treatment (n = 23), implant surgery (n = 22), endodontic treatment (n = 9), reduction of temporomandibular joint dislocation (n = 1), and treatment of traumatic injuries (n = 1), with treatments mostly performed on adult patients. CONCLUSIONS: With increasing demand for minimally painful treatment, cases using IV sedation are on an upward trend and are expected to continue to increase.

A survey of dental treatment under general anesthesia in a Korean university hospital pediatric dental clinic

BACKGROUND: In South Korea, the number of cases of dental treatment for the disabled is gradually increasing, primarily at regional dental clinics for the disabled. This study investigated pediatric patients at a treatment clinic for the disabled within a university hospital who received dental treatment under general anesthesia. This data could assist those that provide dental treatment for the disabled and guide future treatment directions and new policies. METHODS: This study was a retrospective analysis of 263 cases in which patients received dental treatment under general anesthesia from January 2011 to May 2016. The variables examined were gender, age, reason for anesthesia, type of disability, time under anesthesia, duration of treatment, type of procedure, treatment details, and annual trends in the use of general anesthesia. RESULTS: Among pediatric patients with disabilities who received dental treatment under general anesthesia, the most prevalent age group was 5–8 years old (124 patients, 47.1%), and the primary reason for administering anesthesia was dental anxiety or phobia. The mean time under anesthesia was 132.7 ± 77.6 min, and the mean duration of treatment was 101.9 ± 71.2 min. The most common type of treatment was restoration, accounting for 158 of the 380 treatments performed. CONCLUSIONS: Due to increasing demand, the number of cases of dental treatment performed under general anesthesia is expected to continue increasing, and it can be a useful method of treatment in patients with dental anxiety or phobia.

Using nasal cannula for sevoflurane deep sedation in emergency dental treatment

BACKGROUND: Emergency room doctors run into difficulties in treating injured pediatric patients because usually they fell into panic after trauma. In these situation, deep sedation with sevoflurane is fully recommendable method. The conventional way can interrupt common dental treatment procedure. METHODS: In the present study, nasal cannula was used for sevoflurane deep sedation in 11 dental emergency treatment. Age ranged from 0 to 3 years old (average of 1.8 years). RESULTS: Treatment duration was from 10 to 35 minutes (average of 16.7 minutes). Average duration of sedation was 25.5 minutes ranging from 15 to 45 minutes. CONCLUSIONS: It has advantages to use nasal cannula for sevoflurane deep sedation rather than conventional intubation; saves time and secures good operation field.