The Assessment Of The Antibacterial Effect Of Diode Laser Versus Nanosilver Fluoride On Streptococcus Mutans Count Of Oral Biofilm Of Primary Teeth

Aim: Streptococci are the most frequent cariogenic bacteria in tooth decay and are often present in the human oral cavity. The purpose of this study was toevaluate the antibacterial outcome of diode laser versus Nanosilver fluoride (NSF) on the count ofStreptococcus mutans inan oral biofilm of primary teeth in-vitro. Materials and Methods: Seventy-two extracted human primary anterior teeth were prepared and equally split into four groups based on the test agent employed: group I: control group with two subdivisions (Negative control with no oral bacterial biofilm formation and Positive control with oral bacterial biofilm formation), group II: NSF, group III: diode laser 980 nm with 2 subdivisions(high power and low power) and group IV: NSF, then low power diode laser.A biofilm of Streptococcus mutans (ATCC 25175) was prepared and grown on the enamel surface of teeth. Therapy before and after, environmental scanning electron microscope (ESEM), and energy dispersive X-ray analysis (EDX) were used to analyze the surface morphology of the enamel surface. Following the medical treatments, the samples were put back in the glass tubes containing the 1ml phosphate buffer and incubated for 24 h. After that, the test tube was sonicated to separate the biofilm formed on the enamel surface of the sample, and the number of colony-forming units per milliliter in each group (CFU/ml dry biofilm weight) was determined. Results: NSFand diode lasers (980nm) showed significant antibacterial effects on Streptococcus mutans biofilm, and reduce its number and vitality. Group II (NSF) and group IV (NSF and Low power diode laser) exhibited the uppermost reduction of bacterial count and viability, although no statistically significant difference was found between them where (p=0.654) followed by group III (diode laser group) without noticeable change between thehigh power diode and low power diode groups where (p=0.506), althoughthe low power diode gave better results than the high power diode. Conclusion: The application of NSF, diode laser, or their mixture effectively reduces Streptococcus mutans bacterial colonies in the oral biofilm. NSF is the most effective agent against the viability and reduction of Streptococcus mutans followed by the diode laser, although there is no major change among high power and low power diodes. NSF and diode laser prevented the loss of minerals on the enamel surface of the specimen, and the content of calcium and phosphorus was retained and increased in all groups