IntroductionPeriodontal diseases are referred to as inflammatory processes in periodontal tissues in response to the aggregation of bacteria on the teeth. The aggregation rarely leads to evident infection, but the inflammatory response caused in the gingival tissue is responsible for the gradual loss of dental collagen's attachment to the alveolar bone. Left overlooked, this phenomenon might end in increased dental mobility and eventually edentulism.1 Production of destructive metabolites by gram negative and positive bacteria of the microbial plaque in the oral cavity causes gingivitis, which can play a key role in the progression of inflammation to periodontal diseases.
2Aggregatibacter actinomycetemcomitans is an immobile microaerophilic, facultative anaerobic, gram negative coccoid rod, 3 strongly associated with pathogenesis of periodontal diseases, particularly aggressive generalized periodontitis.4 Some of this bacterium's membranous proteins play an important role in attachment to and penetration in tissue cells.5 Other virulence factors secreted by this bacterium include an agent that inhibits the reproduction of fibroblasts and a leukotoxin that kills the leukocytes. 6 Despite the many complications caused by periodontitis, no treatment protocol is known to be able to fully control this disease. Currently, a combination of mechanical treatments and systemic antibiotics are used as treatment 7 ; however, periodontal pathogens are not completely removed by the mechanical removal of the biofilm; and there are problems associated with the use of antibiotics, Abstract Introduction: Considering the importance of prevention in periodontal diseases and the important role of Aggregatibacter actinomycetemcomitans in induction and progression of these diseases, the aim of the present in vitro study was to compare the antimicrobial effects of chlorhexidine digluconate (CHX), curcumin and light-emitting diode (LED) laser, on this bacterium. Methods: Antimicrobial activity of curcumin (5 mg/ml), CHX (2%), LED (120 J/cm 2 ) and LED + curcumin (120 J/cm 2 + 2.5 mg/ml) against A. actinomycetemcomitans were tested in vitro, using micro-broth dilution test. One-way analysis of variance (ANOVA) and Tukey's HSD tests served for statistical analysis. Results: Regarding the minimum inhibitory concentration (MIC), CHX had a significantly lower MIC than curcumin (P < 0.05). Sorted out by bacterial growth from lowest to highest, were CHX, LED + curcumin, curcumin, and LED groups. All the differences were found to be statistically significant (P < 0.05) except for the LED group. Conclusion: We conclude that curcumin is an effective substance in preventing the growth of A. actinomycetemcomitans, whose impact is reinforced when used simultaneously with photodynamic therapy (PDT).
