Conduct of the study
dryness
ADHESION, PLAQUE
The following factors were examined. Sex, age, number of remaining teeth, Oral Hygiene Index-Debris Index (OHI-DI) [The TCI score was used to determine the degree of tongue coating via visual inspection. The tongue surface was divided into nine areas, and each area was rated on a 3-point scale (score 0–2). The total score was calculated by summing scores of the nine areas. The degree of oral dryness was measured by placing the surface of a dental mirror on the buccal mucosa, and when the buccal mucosa stuck to the mirror, it was considered dry. The number of bacteria in the saliva was measured using real-time PCR to determine the amount of bacterial DNA in the collected saliva.Bacterial counts were measured in two saliva samples: one at the time of plaque adhesion and one after brushing. Saliva samples were collected and left unbrushed for 30 h to quantify the number of bacteria. Then, the OHI-DI scores were measured. Subsequently, the participants were instructed to brush their teeth for 3 min. After brushing, they were instructed to rinse their mouths with 180 mL of tap water. Three hours later, the specimens were collected, the number of bacteria in the saliva was determined, and the OHI-DI was measured using the same method as before brushing.