Evaluation of Microbial Leakage at Implant Abutment Interfact for Different Implant Systems: An In Vitro Study.

Two-stage implant systems result in gaps and cavities between implant and abutment that can act as a trap for bacteria and thus possibly cause inflammatory reactions in the peri-implant soft tissues. These gaps between the components are inevitable, and their clinical significance has so far been mostly neglected by both manufacturers and clinicians. This study is thus intended to evaluate microbial leakage at implant abutment interface in different implant systems. Four different systems, the Nobel tri-channel, the Nobel conical, the Equinox, and the Straumann, were used for this study. One microliter of a fresh broth suspension of Streptococcus mutans was added to the implant fixture (implant body). The implant was immersed in fresh heart brain infusion and was incubated at 37° for 48 hours. After incubation, 10 µL of the broth was made as lawn culture on sterile agar and the colonies were counted and recorded as colony-forming units per milliliter. Statistical tests were carried out on SPSS software and tests included analysis of variance (ANOVA) and P value was derived using Tukey's honestly significant difference post hoc test. After incubation, results were analyzed by evaluating the microbial leakage from each sample and it was observed that Nobel tri-channel had the least amount of microbial leakage and Equinox had maximum microbial leakage. The difference among all implant systems was statistically significant P < 0.05. The study concluded that least micro-leakage was found in the Nobel tri-channel whereas maximum microbial leakage was present in Equinox and Straumann.

Detection of csgA gene in carbapenem-resistant Acinetobacter baumannii strains and targeting with Ocimum sanctum biocompounds.

OBJECTIVES: Carbapenem-resistant Acinetobacter baumannii (CRAB) is considered highly virulent due to csgA gene-mediated biofilm formation. The present study aimed to target the same gene, employing the antibiofilm effect of Ocimum sanctum (O. sanctum) essential oil compounds among CRAB strains. MATERIALS AND METHODS: A semi-quantitative adherent bioassay was performed to detect the biofilm formation in 73 CRAB strains. This was followed by molecular characterization, Polymerase Chain Reaction (PCR) amplification, and csgA gene sequencing. An antibiofilm assay under in vitro conditions, with essential oils of O. sanctum was performed. This was followed with further docking analysis of csgA protein with the selected compounds from the O. sanctum essential oils. A Molinspiration assessment was also done to elicit the drug likeliness of the biocompounds. RESULTS: The biofilm assay showed 58.9% as high-grade and 31.5% as low-grade biofilm formers, while 9.58% were non-biofilm formers. Molecular characterization of the csgA gene showed 20.54% (15/73) positivity. The strains that were imipenem resistant also showed the csgA gene to be present (100%; 15/15), with 60% (9/15) and 20% (3/15) for meropenem and doripenem resistance respectively. A crystal violet assay for determining cell viability was done in vitro, which gave Minimum biofilm inhibition concentrations of 50% (MBEC50) at 25 µl and 90% (MBEC90) at 50 µl. The docking analysis done in silico showed benzofuran to possess the lowest binding energy and highest hydrogen bond interactions. CONCLUSION: The results indicate benzofuran, from the O. sanctum essential oils, to be effective in targeting the csgA gene among CRAB strains. Additionally, validation of these findings through in vivo studies is required.