Dental Deposits ; therapy ; Dental Porcelain ; Dental Prosthesis Repair ; methods ; Humans

Fresh dental calculus were scratched and rinsed with distilled water, and then dissolved by HNO3. Simulated body fluid was used as control. Aqueous ammonia was added to step up the pH. FSEM and FI-IR were used to analyze the crystal character of deposition. Turbid occurred when pH = 5.4 and deposition occurred when pH = 5.6. Ribbon-like crystal, which was the same as the crystal in natural dental calculus was observed in experimental group and was evidenced to be hydroxyapatite (HAP) by FT-IR. HAP formation through homogeneous phase redeposition of dissolved dental subgingival calculus may be related with the existing template molecules in dental subgingival calculus resolution, which induce the biomineralization of HAP formation.
Calcinosis ; pathology ; Calcium Phosphates ; chemistry ; Crystallography ; Dental Calculus ; chemistry ; Dental Plaque ; chemistry ; Gingival Diseases ; etiology ; Humans ; Hydroxyapatites ; chemistry

PURPOSE: The effects of magnetostrictive and piezoelectric devices on tooth surfaces seem to differ with regard to the root surface roughness they produce. This study aimed to compare the results of scaling using magnetostrictive and piezoelectric devices on extracted teeth. METHODS: Forty-four human extracted teeth were assigned to four study groups (n=11). In two groups (C100 and C200), the teeth were scaled using a magnetostrictive device and two different lateral forces: 100 g and 200 g, respectively. In the other two groups (P100 and P200), the teeth were scaled with a piezoelectric device with 100 g and 200 g of lateral force, respectively. he teeth were scaled and the data on the duration of scaling and the amount of surface were collected and analyzed using the t-test. RESULTS: The mean time needed for instrumentation for the piezoelectric and magnetostrictive devices was 50:54 and 41:10, respectively, but their difference was not statistically significant (P=0.171). For root surface roughness, we only found a statistically significantly poorer result for the C200 group in comparison to the P200 group (P=0.033). CONCLUSIONS: This study revealed that applying a piezoelectric scaler with 200 g of lateral force leaves smoother surfaces than a magnetostrictive device with the same lateral force.
Dental Calculus ; Dental Scaling ; Humans ; Tooth ; Tooth Extraction ; Ultrasonics

This study is based on the result of oral examination of 'A' airliner employees in the period of June 1997 and December 1997. The purpose of this study is to analyze the distribution of dental diseases among workers and the relationship between income level and dental healthiness. Based on the above analysis, this study further tries to indirectly evaluate the method of prophylaxis. Following is the list of basic findings of this study: Firstly, it was found that male workers tend to have inferior dental condition compared with female workers. Also, dental condition of technicians was found to be worse than that of office workers. Secondly, it was found that dental caries decreased with the age. However, periodontal disease was increasing with the age. Therefore, this result leads us to convince that the education should be focused on 'how to brush your teeth' in order to prevent periodontal diseases. Thirdly, more than 40% of the examined were found to be carrying dental calculus related diseases (67.2%) and cervical abrasion (40.5%), respectively. In conclusion, we became to know that the treatment of cervical abrasion and dental calculus at the Dental Clinic is effective in helping 'A' Airliner employees to have better dental status.
Calculi ; Dental Calculus ; Dental Caries ; Dental Clinics ; Diagnosis, Oral* ; Education ; Female ; Humans ; Male ; Periodontal Diseases ; Stomatognathic Diseases

This study was attempted to investigate changes in physiochemical properties of the preparation of saccharification kochujang with retrogradated cooked rice, bread, rice cake and sensory evaluation during 60days aging. 1. Moisture content in 4 samples were slowly increased and pH of kochujang was slowly decreased during aging. 2. Reducing sugar content were about 1.4~2 times higer than T3 and T2 at 50days of aging. 3. In no significant difference 4 samples, the level of adipic acid, citric acid, malic acid was the most and that of acetic acid, iso-butyric acid, fumaric acid, lactic acid, tartaric acid was smaller. 4. Sensory evaluation conducted by fifteen university students as panelist showed that their were more significant difference among four samples and notable preferance for T3 over T0, T1, T2.
Acetic Acid ; Aging* ; Bread ; Citric Acid ; Dental Calculus ; Humans ; Hydrogen-Ion Concentration ; Lactic Acid ; Starch*

For the purpose of ascertaining the status of physical growth and health status of the University students, a intensive survey was conducted by the authors towards a total of 2,638(male; 2,228, female;410) who passed the written entrance examination at the Seoul National University. The items included the measurements on physical growth, various physical indexes, visual acuity, tuberculosis and dental status. The findings and results can be summarized as follows : 1. Physical Growth. No signigicant difference was found in the physical growth between classes(literature and science) and by ages. In males, the means of body height, body weight, chest-girth and sitting height were 168.0+/-5.07cm, 55.7+/-5.71kg, 85.8+/-4.4cm and 91.5+/-2.21cm, respectively. In females, these were 157.4+/-4.57cm, 00.4+/-5.75kg, 80.3+/-4.51cm and 86.1+/-3.30cm, respectively. Basing on the above measurements several physical indexes were calculated as follows ; Relative body weigh 33.15 in males and 32.02 in females. Relative chest-girth 51.07 and 51.01, relative sitting-height 54.46 and 54.70 Rohrer index 1.00 and 1.02, Kaup index 1.97 and 2.04, Vervaeck index 83.63 and 83.03, and Pelidisi index 89.94 and 92.45. 2. Visual Acuity. Among the students of science classes those of 0.8 and below in vision on left and right occupied 46.4% and 45.0%, those of 0.6 and below 39.1% and 41.2%, respectively. Among the students of literature classes those of 0.8 and below occupied 46.3% and 42.9%, and those of 0.6 and below occupied 41.4% and 39.0, respectively. In males those of 0.8 and below occupied 46.8% and 44.5% and 0.6 and below occupied 41.9% and 39.7%, while in females 0.8 and below occupied 43.9%, and 42.4%, and 0.6 and below occupied 38.3%% and 37.3%, respectively. In males those of 0.8 and below in corrected vision occupied 12.1% and 10.3%, while in females 12.9% and 12.2%, respectively. More students of abnormal vision were found among science classes and the proportions of corrected vision were 38.9% and 37.4% in males, and 33.9% and 33.2% in females, respectively. 3. Tuberculosis. Among the total, 55 students were diagnosed as tuberculosis, of whom 50 were minimal cases, 2 were moderately advanced cases and 3 were far advanced cases. 4. Dental Status. Among the total, 81.2% were of decayed teeth, 20.8% filled, 9.5% missed, 5.0% extraction needed, 9.1% sunplatinum bridges, 3.3% golden bridges and 5.5% golden inaly. Regarding tartar on teeth moderate, heavy and light grades occupied 49.5%, 29.7% and 20.3%, respectively and 0.8% had none. 5. Comprehensive evaluation. According to the criteria 4 grades were applied to comprehensive evaluation as follows : A---excellent in physical status B---with some physical defects but no difficulties in study C---need treatment D---need treatment and rest. Out of the total, A grade occupied 21.6%, B 76.2% and C. and D 2. 2.
Body Height ; Body Weight ; Dental Calculus ; Female ; Humans ; Male ; Seoul ; Tooth ; Tuberculosis ; Visual Acuity

PURPOSE: 99mTc-HMPAO is a radiopharmaceutical for imaging cerebral blood flow. HMPAO (RR, SS)-4,8- diaza-3,6,6,9-tetramethylundecan-2,10- dione bisoxime) has three stereoismers such as, meso-, d-, and l-HMPAO. Techentium complexes of meso-HMPAO and d,l-HMPAO are known to have different in vivo brain uptakes. In this study, enantiomers of HMPAO (d-HMPAO and l-HMPAO) were separated from d,l-HMPAO. These enantiomers were labeled with 99mTc and the biodistribution studies were performed in mice. MATERIALS AND METHODS: An intermediate imine product was produced from 2,3-butanedione monooxime and 2,2-dimethyl- 1,3-propanediamine (54% yield) and was reduced into a mixture of three isomers (35% yield). The meso-isomer was separated from d,l-mixture by repeated fractional crystallization (11% yield). The d- and l-enantiomers were subsequently separated by co-crystallization with optical isomers of tartaric acid (25% and 5% yield, respectively). Each enantiomeric HMPAO was labeled with 99mTc by reacting with SnCl2 2H2O and 99mTc-pertechnetate. Biodistribution study was performed 1 hr after tail vein injection to ICR mice. RESULTS: Radiochemical purities of each compound were over 80%. In biodistribution study, the brain uptakes of d,l- d- and l-form were 1.34, 1.12 and 1.67% ID/g, respectively. In case of l-Isomer the brain uptake was higher (1.5 fold) than d-isomer. CONCLUSION: We successfully purified each enantiomeric HMPAO. In biodistribution study of stereoismers of 99mTc-HMPAO in mice, l-HMPAO may show better brain image than d,l-HMPAO which was supplied in a commercial kit.
Animals ; Brain* ; Crystallization ; Dental Calculus ; Diacetyl ; Mice ; Mice, Inbred ICR ; Stereoisomerism ; Technetium Tc 99m Exametazime* ; Veins

The purpose of this study was to develop effective dental hygiene chews for cats based on the anatomical features of the dentition and patterns of chewing motion. All cats were volunteered for dental prophylaxis followed by dental impressions using yellow stone and alginate under general anesthesia. Twenty parameters related to dentition were defined in order to compare dental impressions using digital caliper. For the chewing motion study, patterns of chewing motion were identified based on recordings made with a digital camera. Ten cats (4 domestic shorthairs, 2 Russian blues, 1 American shorthair, 1 Persian, 1 Turkish Angora, and 1 Devon Rex) were recruited for the study. The parameters related to teeth and oral size were similar among the studied cats. Chewing motion can be described as more of a guillotine-like motion rather than a crushing motion, with cats chewing 3–7 times before swallowing. The chewing pattern of cats involves shearing for a short period of time followed by immediate swallowing. Therefore, the overall size of the dental hygiene chew could be determined based on the measurement of the oral size for inducing chewing. The surface details of the dental hygiene chew could be designed for prevention and removal of dental calculus and plaque in cats considering the anatomical teeth parameters. Dental hygiene chews customized for cats considering the different anatomical features of their teeth might be effective for oral care.
Anesthesia, General ; Animals ; Cats ; Deglutition ; Dental Calculus ; Dental Prophylaxis ; Dentition ; Gingiva ; Mastication ; Oral Hygiene ; Periodontal Diseases ; Tooth

The samples of dental deposit plaque collected from 30 people in the faculty of Natural Science were stained by Gram technique. A bacterial prosperious component was detected including Gram (+) cocci, Gram (-) cocci, red and thin cell, red and long cell, straight and curved Gram (-) cells, thin spinal cells … Microorganism population on the deposit plaque under the gun includes bacteria, cocci, and spirochaetes. 3 genera were determined including Streptococcus, Lactobacillus and Actinomyces, with a highest incidence of Streptococcus. The representative genus has the characteristic similar to Streptococcus mutans and it seems that it plays an important role leading to caries
Dental Plaque ; Bacteria ; Dental Care

BACKGROUND AND OBJECTIVE: The role of dental plaque as the etiology of caries and periodontal diseases has long been established. Therefore, plaque control is central to the prevention and management of these oral diseases. Among the different means of self-performed plaque control, brushing is the most essential. Moreover, toothpaste is a common adjunct during tooth brushing, as its abrasive contents are believed to enhance plaque removal. This study aimed to compare the effectiveness of plaque removal when brushing with a sodium bicarbonate abrasive-containing toothpaste, compared to brushing using an abrasive-free toothpaste.

METHODS: Twelve students from the University of the Philippines College of Dentistry participated in the study. The subjects discontinued all oral hygiene measures for a minimum of 48 hours. Using the Modified Bass technique, they performed tooth brushing for two minutes, using either an abrasive-free or abrasive containing toothpaste. Toothpaste allocation was randomized via fishbowl method. Pre-brushing and post brushing plaque scores were recorded using the Turesky modification of Quigley-Hein plaque index. A washout period of 11 days was implemented before crossover to the second round, wherein employed toothpastes were switched. The difference in plaque reduction between the two kinds of toothpaste was analyzed using Wilcoxon signed rank test.

RESULTS AND CONCLUSION: Overall plaque reductions were 75% for the abrasive-free toothpaste and 73% for the abrasive-containing toothpaste. The difference between the toothpaste was statistically insignificant (p=0.48). Therefore, based on the study, brushing with a sodium bicarbonate abrasive-containing toothpaste resulted in similar levels of plaque removal, compared to brushing with an abrasive-free toothpaste. There is insufficient evidence that abrasives in toothpaste result in more effective dental plaque removal.