Effects of Fluoride Mouth Rinsing on Salivary Factors in Children

Objectives: The aim of this study was to clarify 3-year changes in salivary factors such as salivary flow rates (SFR), pH, salivary buffer capacity（SBC）as well as Mutans streptococci (MS) levels obtained from nursery school children with fluoride mouth rinsing around Sapporo and preschool children without rinsing in Sapporo, aged 3, 4 and 5 years old (yrs).
Methods: Three-year follow-up data from the age of 3 to 5 was used. Forty-six children and their guardians gave informed consent to participate in this study; twenty-four 4 and 5 yrs nursery school children with 450ppmF fluoride mouth rinse once a week for two years (Group A), and twenty-two preschool children without fluoride mouth rinse (Group B). Whole unstimulated saliva samples were collected into pre-weighed tubes for 5 minutes. SFR were calculated (ml/min) after being re-weighed. pH levels and SBC were determined using a portable pH meter (Checkbuf^TM Morita, Tokyo) and MS levels were determined using MUCOUNT^®　　(Showayakuhinkakou, Tokyo).
Kruskal-Wallis test with Bonferroni correction was used among the data of different age categories in each group. MS levels (0～3) were analyzed via χ² test. The Mann-Whitney test was used to compare Group A and Group B.
Results: SFR(ml/min) showed statistical increases with age (p<0.01) in both groups. SBC showed statistical increases with age in Group A (p<0.01), but not in Group B. For the comparative study between with and without rinsing, Group A SBC levels (pH6.07±0.88) tended to be higher than Group B (pH5.72±0.57) (p=0.066); and Group A MS levels (1.08±0.88) tended to be lower than Group B (1.89±0.81) (p=0.052) in 5 yrs children.
Conclusions: SFL showed increase with age, and fluoride mouth rinsing tends to affect SBC and MS levels in saliva.