Abstract
BACKGROUND/PURPOSE: Infectious complications after invasive surgeries may originate from oral sources through either hematogenous infection or direct exposure to salivary bacteria. Perioperative oral management aims to remove oral foci of infection. However, the type of oral care that can reduce the salivary bacterial load remains unclear. This study aimed to identify factors influencing salivary bacterial counts during the perioperative period in patients with malignant tumors and to evaluate the effectiveness of tooth brushing and povidone-iodine mouthwash in reducing oral bacterial counts. MATERIALS AND METHODS: Patients aged ≥18 years who underwent surgery under general anesthesia for malignant solid tumors other than head and neck cancer were included. Participants were randomly assigned to the brushing or povidone-iodine mouthwash groups. Factors such as sex, age, primary disease, preoperative blood-test results, oral functional metrics, and salivary bacterial counts were analyzed. Saliva samples were collected before and on the day after surgery, both before and after oral-care interventions. The total bacterial and streptococcal counts were determined using real-time polymerase chain reaction (PCR), and delayed real-time PCR was used to determine the viable bacterial count. RESULTS: Postoperatively, the salivary bacterial counts increased slightly. Significant factors affecting postoperative bacterial counts included high preoperative counts and postoperative fasting status. Brushing increased salivary bacterial counts, whereas the povidone-iodine mouthwash decreased them. CONCLUSION: Poor preoperative oral hygiene and postoperative fasting were significantly associated with increased salivary bacterial counts. The povidone-iodine mouthwash reduced postoperative bacterial counts, indicating its effectiveness as a perioperative oral-care method.