Comparison of antibacterial activity of two dentin bonding systems using agar well technique and tooth cavity model.

OBJECTIVE: This study compared the antibacterial activities of two dentin bonding systems (ABF, Kuraray and Reactmer Bond, Shofu) by a conventional agar well technique and a newly designed in vitro test using tooth model. METHODS: In the agar well technique, the test materials were filled in the wells of Muller Hinton agar plates inoculated with Streptococcus mutans NCTC10449, and the diameters of inhibition zones produced around the materials were measured after 24h of incubation. For the tooth model test, three cavities (diameter 1mm, depth 2mm) were prepared in the flat occlusal dentin of human extracted molar. After sterilization, the teeth were left in broth culture of 1.56 x 10(8)CFU/ml of S. mutans at 37 degrees C for 72h for allowing bacteria to invade the cavity. The dentin bonding systems were applied separately to each of the two infected cavities, and the third cavity was left unapplied for control. After sealing the occlusal surfaces, the teeth were kept in physiologic saline solution at 37 degrees C for 72h. The standardized amounts of dentin chips (120+/-5mg) were obtained from the cavity walls and the number of bacteria recovered was determined. The results were analyzed by One Way ANOVA, Kruskal Wallis and Mann-Whitney's U tests. RESULTS: The primer of ABF and Reactmer Bond produced inhibition zones with similar sizes (p>0.05), but the bonding resin of ABF did not produce any inhibition. When tested by the model cavity method, the application of ABF resulted in significantly less bacterial recovery than Reactmer Bond (p<0.05), demonstrating substantial antibacterial effects. CONCLUSIONS: The tooth model method used in this study was effective for evaluating the substantial antibacterial effects of dentin bonding agents, and the experimental dentin bonding system ABF was demonstrated to be able to inactivate the bacteria in the cavity effectively in comparison with little antibacterial activity shown by Reactmer Bond.

A comparative study on detection of Ornithobacterium rhinotracheale antibodies in meat-type turkeys by dot immunobinding assay, rapid agglutination test and serum agglutination test.

The objectives of the present study were to develop a dot-immunobinding assay (DIA) and a serum agglutination test (SAT) for detection of Ornithobacterium rhinotracheale, to compare the rapid agglutination test (RAT) and the SAT, and to make a serosurvey of O. rhinotracheale exposure on turkey farms in Turkey. Antiserum against O. rhinotracheale bacterin was prepared in rabbits and 72 serum samples were collected from turkeys with respiratory signs on four farms. Comparison of the tests showed that 55.5, 48.6 and 40.3% of serum samples were positive by RAT, SAT and DIA, respectively. The sensitivity of the DIA appeared to be lower than that of the agglutination tests but the specificity is not known.