Comparison of Bonding Strength by Cleaning Method of Pediatric Zirconia Crown Contaminated with Saliva or Blood / 대한소아치과학회지

The objective of this study was to compare the shear bonding strength of zirconia after cleaning the crown contaminated by saliva or blood and determine the effect of thermocycling. 180 specimens were embedded in acrylic resin. 20 Specimens in the positive control group were bonded with resin cement without contamination. 20 Specimens in the negative control group were washed with water for 20 seconds and then dried for 10 seconds. 120 Specimens contaminated by saliva or blood were cleaned by using three cleaning methods: 37% phosphoric acid gel, commercial cleanse, and 2.5% NaOCl. All samples were bonded with resin cement and divided into two subgroups: One was not aged, and the other was tested with 30,000 thermocycling. In both groups contamination by saliva and blood, no statistically significant difference was not found in control, groups cleansed by commercial cleanser and 2.5% NaOCl. When the groups cleansed with water and 37% phosphate gel were compared with the control, significantly low shear bond strength was shown. Thermocycling group showed statistically significantly low shear bond stress compared to the groups without thermocycling. When zirconia was contaminated by saliva or blood, its original shear bond strength could be obtained if it was cleaned with commercial cleanser or 2.5% NaOCl.

Antimicrobial Effect on Streptococcus mutans in Photodynamic Therapy using Different Light Source / 대한소아치과학회지

In a photodynamic therapy, the difference of antibacterial capacity was compared according to the type of source of light when the same quantity of energy is irradiated.After S. mutans is formed in planktonic state and biofilm state, erythrosine diluted to 40 µM was treated for 3 minutes, and as the type of light source, Halogen, LED, and Plasma arc were used, which were irradiated for 30 seconds, 15 seconds and 9.5 seconds, respectively.After the completion of the experiment, CFU of each experiment arm was measured to compare the photodynamic therapeutic effects according to each condition.The CFU of each experiment arm had no statistically significant difference.Under the same quantity of energy, the photodynamic therapeutic effect can be said to be the same regardless of types of light source, which is a useful result in the clinical field with various light irradiators.

A Comparison of Anti-Pseudomonal effects by Multi-purpose Contact Lens Solutions

PURPOSE: To compare the antimicrobial effects of various kinds of multi-purpose solutions, study effective ways of washing contact lens (CLs), and suggest the most effective lens care system using P. aeruginosa-contaminated CLs. METHODS: Each disposable soft CL was incubated in 0.1 ml of diluted solution of P. aeruginosa standardstrain (10(8)CFU / mm(3)) and 0.9 ml tryptic soy broth in cell culture wells for 24 hours. In the first experimental group, to find the most antimicrobial solution, 40 CLs contaminated by P. aeruginosa were divided into four subgroups washed with four different kinds of multi-purpose solutions. Ten CLs were used in each subgroup and in the control group; Ten CLs contaminated by P. aeruginosa were washed with phosphate buffered saline (PBS) instead of cleaning solution. In the second experiment groups to find the most effective way of washing, using only Renu Multiplus multi-purpose solutionR we compared the antimicrobial effect of four different ways of washing including 30 seconds rubbing, 30 minutes soaking, 4 hours soaking, 30 seconds rubbing and 4 hours soaking. RESULTS: There was no significant difference of antimicrobial effect between four kinds of multi-purpose solutions. All methods have a significant antimicrobial effect over control group (P<0.001) and the most effective method of washing CLs was 4 hours soaking. CONCLUSIONS: we should advise all the soft CL users that they should have their CLs soaked over 4 hours everyday after wearing it.

The clinical results of hydrophilic acrylic lens

PURPOSE: To study visual prognosis and postoperative refractive status and complications after in the bag implantation of newly-introduced hydrophilic acrylic lens (ACR6D, CORNEAL(R) Co. France). METHODS: This study was a retrospective medical record review that in experimental group (50 eyes) we implanted CORNEAL(R)lens in the bag and in control group (50 eyes) we did Acrysof(R) lens after phacoemulsification by one surgeon. We checked automated refraction or manifest refraction of all patients and defined refractive error was a subtraction of preoperative desired refraction from postoperative spherical equivalent. RESULTS: In experimental group, best corrected visual acuity (log MAR) was 0.11+/-0.13 at 2 months after surgery and 0.13+/-0.11 at 6 months. In control group, that was 0.14+/-0.17 at 2 months after surgery and 0.21+/-0.30 at 6 months. There was no statistically significant difference between the two groups. In experimental group, refractive error was -0.56+/-0.73 diopter (D) at 2 months after surgery and -0.41+/-0.90 D at 6 months. In control group, that was 0.14+/-0.80 D at 2 months after surgery and 0.24+/-0.67 D at 6 months. There was a statistically significant difference of refractive error between the two groups at 2 months and 6 month after surgery (p=0, p=0.03). In experimental group, the rate of postoperative lens epithelial cell proliferation contiguous to continuous circular capsulorhexis was higher than those in control group (p=0). CONCLUSIONS: We found no statistically significant difference of postoperative visual acuity between CORNEAL(R) and Acrysof(R) lens implanted in the bag after phacoemulsification. But mean refractive error in eyes implanted with CORNEAL(R) lens was -0.56 D at 2 month after surgery, -0.41 D at 6 month and we recommended preoperative desired refraction of CORNEAL(R) lens should be more hyperopic and postoperative lens epithelial cell proliferation be checked carefully.