The effect of contamination on bonding of orthodontic brackets with a self-etching primer/adhesive / 대한치과교정학회지

The purpose of this study was to investigate the influence of water, saliva, and blood contamination on the bonding strenght of metal brackets with a self-etching primer/adhesive to enamel. Ninety-six extracted human teeth were divided into four groups. The brackets were bonded to enamel with a self- etching primer (3M/Unitek Dental Products, Monorovia, California) according to one of four protocols. The teeth were bonded in a dry condition (group D) or in contamination with distilled water (group W), artificial saliva (group S), or fresh human blood (group B). Shear bond strengths were tested using an Instron Universal testing machine. After debonding, bracket and tooth surfaces were examined with a stereomicroscope. In each group, four samples were selected and examined with a Scanning electron microscope of the prepared enamel surface and resin-enamel interface. The results obtained were summarized as follows: Shear bond strength in group D (15.22 +/- 2.86 MPa) and W (16.20 +/- 3.85 MPa) were higher than in group B (12.56 +/- 2.94 MPa) (p 0.05). There was a tendency to have less residual adhesive remaining on the enamel surfaces of group B than group D. The SEM morphology of group D and W showed a more roughened etching pattern than group S and B. Water or saliva contamination on bonding of orthodontic brackets with Transbond plus self etching primer had almost no influence on bond strength. In this study, the blood contaminated group showed the lowest bond strength, but it was above the clinically acceptable bond strength (5.9-7.8 MPa, Reynold, 1975). The results of this study suggest that acceptable clinical bond strengths can be obtained in wet conditions when self-etching adhesives are used.

The Effect of Oral Administration of Postpartum Tonic Agent(MMQ) on Postpartum Anemia, Obesity and Uterine Involution furing Puerperium / 대한주산의학회잡지

OBJECTIVES: The purpose of this study was to evaluation the effect of administration of postpartumtonic agent(MMQ) on postpartum anemia during puerperal period, obesity control and uterine involution. SUBJECTS AND METHODS: From June 2002 to November 2002, twenty women who underwent spontaneous vaginal delivery at department of obstetrics and gynecology, college of medicine, Pochon CHA University ghopital were included in this study. All women were randomly assigned to receive postpartum tonic agent(MMQ, Albiomed Co.Ltd) or placebo two times a day after each meal for four weeks. They were assessed obesity test(BMI), hematologic examination(CBC, reticulocyte count), liver function test(AST/ALT) and ultrasound test at first day and 28th days after delivery. RESULTS: There was no statistically significant difference between the two group in demographic characteristics. No statistically significant difference were found in this study between the two group in hemoglobin, hematocrit, BMI and the size of uterus. There was no adverse effect to the tested drug. CONCLUSION: There was no significant difference in efficacy and safety between MMQ and placebo in the effect of postpartum anemia, obesity control and reduction of recovery perod. The following limitations have to be considered; Iron supplement, variable diet, seaweed ingestion, consumption of herb and small sample ize. Therefore, a extensive prospective study with control of these variables should be required.