Quantification of Aggregatibacter actinomycetemcomitans and Porphyromonas gingivalis in Head and Neck Irradiated Edentulous Patients

Objectives: To quantify Aggregatibacter actinomycetemcomitans and Porphyromonas gingivalis in head and neck irradiated edentulous patients (case group) and compare the results with a group of edentulous non-irradiated patients (control group).
Methods: Information such as age, presence of tongue coating, salivary flow and biofilm were collected from the patients of both groups. The presence of tongue coating was examined clinically. Sialometry was analyzed by the stimulated technique of chewing paraffin. Microbiological samples were collected from buccal and labial mucosa and tongue dorsum. Subsequently, the samples were processed and analyzed by qPCR for detecting the presence and quantifying Aggregatibacter actinomycetemcomitans and Porphyromonas gingivalis.
The patiens' clinical parameters were evaluated according to the Mann-Whitney test for two independent samples, Spearman correlation analysis and linear regression. The Mann-Whitney test was used to evaluate the association of the quantity of Aggregatibacter actinomycetemcomitans and Porphyromonas gingivalis and the case and control groups and patients with and without tongue coating. The Spearman correlation analysis was used to correlate the two bacteria with the patients' salivary volume.A linear regression model was developed to understand the separate effect of each variable given the result of the other, which separately evaluated the bacteria in each group with salivary volume and tongue coating. All statistical tests developed in this study considered a significance of 5%.
Results: There was statistical difference in the amount of bacteria among the 24 individuals in the case group and the 26 in the control group. Regarding the tongue coating, there was significance for Aggregatibacter actynomicetemcomitans. For salivary volume, Porphyromonas gingivalis had the highest volume in the case group, whereas Aggregatibacter actynomicetemcomitans was more abundant in the control group. In the linear-regression analysis it was found that the main variable responsible for the difference in the amount of periodontal pathogens was the variable group.
Conclusions: Aggregatibacter actinomycetemcomitans and Porphyromonas gingivalis were present in significant amounts in patients of both groups, with a greater quantity in control patients.