2. Random‐effects metaregression analyses of prevented fractions: D(M)FS.
| Objective | Characteristic | Number of trials | Slope estimate | 95% CI | Slope interpretation | P value | I2 residual variation for heterogeneity |
| (2) | Mean baseline caries | 23 | 1.15% | (‐0.97% to 3.26%) | Increase per unit increase in mean baseline caries DM(F)S | 0.27 | 82% |
| (3) | Fluoridated water | 25 | ‐4.63% | (‐27.13% to 17.88%) | Lower PF in presence of background water fluoridation | 0.68 | 83% |
| (3) | Dentifrice use | 25 | ‐10.01% | (‐26.74% to 6.71%) | Lower PF in presence of dentifrice use | 0.23 | 81% |
| (3) | Any background fluorides | 25 | ‐10.65% | (‐25.86% to 4.56%) | Lower PF in presence of other fluorides | 0.16 | 81% |
| (4) | Self versus operator application | 25 | 8.17% | (‐7.99% to 24.33%) | Higher PF if self applied | 0.31 | 81% |
| (4) | Paint or tray versus toothbrush or floss application | 25 | 3.79% | (‐16.99% to 24.56%) | Higher PF with tray | 0.71 | 83% |
| (5) | Frequency of application > twice per year | 25 | 6.33% | (‐9.48% to 22.14%) | Higher PF if application > twice per year |
0.42 | 81% |
| (5) |
Concentration of fluoride ≥ 10,000 ppm F | 22 | 12.90% | (‐31.48% to 5.67%) | Higher PF if fluoride concentration is ≥ 10,000 ppm F |
0.16 | 80% |
| Placebo versus control | 25 | 17.26% | (3.24% to 31.29%) | Lower PF in presence of placebo group | 0.018 | 73% |
|
| Years of follow‐up | 25 | ‐2.11% | (‐11.50% to 7.27%) | Decrease per unit increase in years follow‐up | 0.65 | 81% | |
| Prior prophylaxis vs no prophylaxis | 25 | ‐2.48% | (‐18.71% to 13.75%) | Lower PF in presence of no prophylaxis | 0.75 | 82% | |
| Dropouts (%) | 23 | ‐0.06% | (‐0.67% to 0.54%) | _ | 0.82 | 82% |
CI = confidence interval D(M)FS = decayed, (missing) and filled permanent surfaces PF = prevented fraction ppm F = parts per million of fluoride