Comparison of Anti Bacterial Efficacy of Photodynamic Therapy and Doxycycline on Aggregatibacter Actinomycetemcomitans

Background Aggregatibacter actinomycetemcomitans (A.actinomycetemcomitans) is an anaerobic bacterium has been frequently associated with aggressive periodontitis. Photodynamic therapy (PDT) is a medical treatment to prevent infection progression that utilizes light to activate a photosensitizing agent. Doxycycline is an antibacterial having photosensitivity. This study aimed to evaluate potential doxycycline as an antibacterial and photosensitizer combine PDT against A.actinomycetemcomitans bacteria. Material and methods Samples were distributed to 4 groups as follow: (1) Groups A treated with a diode laser, (2) Group B treated with doxycycline 0,1% and laser, (3) Group C treated only with Doxycycline 0.1%, and (4) Group D no exposure doxycycline/laser. Data were analyzed by one-way ANOVA and Tukey's HSD test at 5% significance level. Results In this study, doxycycline 0.1% has the effect of reducing the bacterial viability of (59.60±3.26%). Whereas laser exposure 120 s combined with doxycycline produce the effect of bacterial viability reduction (88.50±2.83%) is not significantly different from the effect of laser 120 s exposure (88.79±2.60%). In clinical treatment, the application of laser exposure is generally at the duration of the exposure time of 30 s. The results of this study indicate that the duration of laser exposure 30 s shows a reduction in bacterial viability (44.91±1.69%) equal to the laser and with a combination of doxycycline and laser exposure (70.70±2.43%). So at low doses of laser exposure, doxycycline 0.1% combined with the laser results in the greatest reduction in bacterial viability, significantly different from laser exposure alone. Conclusion at low doses of laser exposure (30s with energy 3.68 J/cm2), doxycycline 0.1% combined with the laser results in the greatest reduction in bacterial viability, significantly different with laser exposure alone.