IADR Abstract Archives
Bioimpedance Growth Measurements of Cariogenic Bacteria at Different Salivary PH
Objectives: Studies to determine the role of bacteria with cariogenic potential and their growth within the biofilm have been carried out. Conventional techniques for counting bacterial growth are accurate but require time and a lot of preparation. Therefore, the implementation of sensitive, fast techniques that do not alter the sample to be studied has become relevant. Impedance is presented as an alternative. Objective: To evaluate the growth of Streptococcus mutans (SM), Streptoccocus salivarius (SS) and Lactobacillus acidophilus (LA) in a biofilm model (3B) using bioimpedance measurements
Methods: 12 sheets of bovine enamel inlaid with silver amalgam (Used as a conductor) were prepared. For each evaluation by bioimpedance, 14 mL of BHI culture broth + yeast was sown with an inoculum of SM, SS, LA, and 3B .0,5 McFarland bacteria, at each pH condition (5.0, 6.5, and 9.0). The impedance was evaluated every 2 hours for 30 hours at 37C at frequencies of 100- 200000 Hz, using a device specially built for this purpose. To contrast the growth results obtained by bioimpedance, the dripping methods, counting colony-forming units (CFU) at 24 hours, and optical absorbance of each bacterium at different PH were carried out. Each test was performed thrice and the linear regression between the bioimpedance-absorbance response was calculated, as well as the correlation coefficient between the variables.
Results: The growth of SS,SS,LA and 3B was identified by means of bioimpedance techniques at pH 5.0 and 6.5. No growth at pH 9.0 was identified in any of the samples.
Conclusions: The bioimpedance technique yielded very similar results to traditional ones. Likewise, this technique showed in detail all the growth phases that cariogenic bacteria underwent, evaluated at different pHs, and that this can represent a simple, fast, and real-time option to identify the growth of cariogenic bacteria.
Methods: 12 sheets of bovine enamel inlaid with silver amalgam (Used as a conductor) were prepared. For each evaluation by bioimpedance, 14 mL of BHI culture broth + yeast was sown with an inoculum of SM, SS, LA, and 3B .0,5 McFarland bacteria, at each pH condition (5.0, 6.5, and 9.0). The impedance was evaluated every 2 hours for 30 hours at 37C at frequencies of 100- 200000 Hz, using a device specially built for this purpose. To contrast the growth results obtained by bioimpedance, the dripping methods, counting colony-forming units (CFU) at 24 hours, and optical absorbance of each bacterium at different PH were carried out. Each test was performed thrice and the linear regression between the bioimpedance-absorbance response was calculated, as well as the correlation coefficient between the variables.
Results: The growth of SS,SS,LA and 3B was identified by means of bioimpedance techniques at pH 5.0 and 6.5. No growth at pH 9.0 was identified in any of the samples.
Conclusions: The bioimpedance technique yielded very similar results to traditional ones. Likewise, this technique showed in detail all the growth phases that cariogenic bacteria underwent, evaluated at different pHs, and that this can represent a simple, fast, and real-time option to identify the growth of cariogenic bacteria.