Atividade do carvacrol e timol in vivo na inibição de streptococcus mutans e experiência de cárie em crianças livres de cárie: um estudo longitudinal

Abstract

This study aimed to compare the anticaries and antimicrobial efficacy of four different substances: 20% carvacrol (CAR), 10% carvacrol in association with 10% thymol (CAR+THY), 20% chlorhexidine (CHX) and 5% sodium fluoride (NaF), in high-risk, caries-free children. One hundred and twenty children, between 36 and 71-months age, were selected from public preschools from a neighborhood in Fortaleza (Ceará). Children were classified as a high caries-risk group according to the American Academy of Pediatric Dentistry Guidelines. These children were randomly allocated into four different treatment groups. Antimicrobial agents were made as varnishes and applied every 3 months, during one year. Patients were monitored every 3 months for new caries lesions. Saliva was collected before treatment initiation (B) and after 7 (D7), 30 (D30), 90 (D90), 180 (D180) and 360 (D360) days post-treatment for MS detection. For microbiological analysis, samples were cultivated on MSB agar media and incubated at 37o C under microaerofilic conditions, during 48 hours. Bacterial colonies were confirmed as being MS through biochemical tests. MS counts were expressed in colony forming units (CFU/mL). Data was considered significant when p<0.02. When comparing MS levels between B and D7, no difference was observed between groups (p=0,032). Comparisons of the percentage MS reduction between groups (D30-D90) demonstrated a significant difference (p=0,002), with a difference between CAR versus CAR+THY (p=0.003), CAR+THY versus CHX (p=0.004), and CHX versus NaF (p=0.014). CAR+THY presented the smallest percentage reduction, while CHX presented the greatest. We observed an increase in MS in the groups treated with CHX and NaF at D360. With the exception of the NaF group, comparisons between dmfs within each group, demonstrated a significant difference between the initial dmfs and the dmfs measured 9 months after treatment initiation. A significant positive correlation between the total dental surfaces and the patient’s age was observed in all groups. No significant difference was found between caries density of the different age groups within and between groups. The dmfs scores did not differ between groups (p=0,746). In conclusion, all treatments produced significant MS reduction with great variations within and between groups, associated with low caries experience.