title: Effect of three concentrations of sodium fluoride dentifrices on clinical caries.
abstract: OBJECTIVE
  To assess whether the anti-caries effectiveness of three concentrations of fluoride dentifrice (placebo, 500 ppm F- and 1450 ppm F-) could be differentiated with small sample sizes in short time frames.
  
  
  METHODS
  A controlled fluoride (F) dose-response study was conducted in concurrence with a supervised school oral hygiene regimen to assess whether dentifrices with increasing fluoride levels could be differentiated with small sample sizes in short time frames. The study was a randomized, double-blind study conducted for a period of 21 months. Subjects (N = 657 with approximately 219 per group) were randomized to placebo dentifrice, 500 ppm F- dentifrice or 1450 ppm F- dentifrice treatments for the first 9 months of the study. Subjects in the placebo group were then switched to either 500 ppm F- or 1450 ppm F- dentifrice for the remainder of the study, while subjects in the fluoride groups continued with their original treatment assignments. A calibrated examiner measured visual-tactile caries as DMFS that was supplemented with a radiographic examination at baseline, 9 months and 21 months for each subject.
  
  
  RESULTS
  The mean caries increments at 9 months were 0.35 surfaces, 0.34 surfaces, and 1.28 surfaces for the 1450 ppm F-, 500 ppm F-, and placebo groups, respectively. The mean caries increments at 21 months were 0.21 surfaces, 0.26 surfaces, 1.75 surfaces and 1.90 surfaces for the 1450 ppm F-, 500 ppm F-, placebo/1450 ppm F-, and placebo/500 ppm F- groups, respectively. The 500 ppm F- and 1450 ppm F- fluoride dentifrices delivered statistically significantly (P< 0.05) lower DMFS scores than the placebo control dentifrice at 9 months, while at 21 months the 500 ppm F- and 1450 ppm F- fluoride dentifrices delivered statistically significantly lower DMFS scores as compared to the both the placebo/500 ppm F- and the placebo/1450 ppm F- dentifrice groups. There was no evidence of a dose response (1450 ppm F- < 500 ppm F-) at 9 months or at 21 months. In this study, the effectiveness of the two fluoride dentifrices was observed at 9 months and these outcomes were still present at 21 months, confirming that caries benefits can be observed in time frames as short as 9 months with approximately 200 subjects per treatment group.
authors.affiliation: Health Care Research Center, The Procter & Gamble Company, 8700 Mason-Montgomery Rd., Cincinnati, Ohio 45040-9462, USA. biesbrock.ar@pg.com
authors.forename: Aaron R
authors.initials: AR
authors.lastname: Biesbrock
authors.forename: Robert D
authors.initials: RD
authors.lastname: Bartizek
authors.forename: Robert W
authors.initials: RW
authors.lastname: Gerlach
authors.forename: Stephen A
authors.initials: SA
authors.lastname: Jacobs
authors.forename: Luis
authors.initials: L
authors.lastname: Archila
mesh_terms: D000704:Analysis of Variance; D002327:Cariostatic Agents / Q000008:administration & dosage*; D002648:Child; D004245:DMF Index; D003731:Dental Caries / Q000188:drug therapy*; D003802:Dentifrices / Q000737:chemistry; D004305:Dose-Response Relationship, Drug; D004311:Double-Blind Method; D005260:Female; D006801:Humans; D008297:Male; D012680:Sensitivity and Specificity; D012969:Sodium Fluoride / Q000008:administration & dosage*
chemical_list: D002327:Cariostatic Agents; D003802:Dentifrices; D012969:Sodium Fluoride