Tagliaferro 2011.
| Methods | Design: Quasi‐randomised CCT Location: Piracicaba, Brazil Study started: Unclear, protocol registered in 2004, before 2008 |
|
| Participants | Number randomised: 219 Number analysed: 181 (109, 110) Age range: 6‐8 years Background exposure to other fluoride: Water 0.7 ppm, toothpaste Other background exposures: OH education |
|
| Interventions |
Comparison: FV versus NT
Group 1(n = 109): 5% NaF varnish (Duraphat® 22,600 ppm F), applied 6 monthly, at schools, to all surfaces of first permanent molars, with small brush, and left to dry Group 2 (n = 110): No treatment All participants received oral health education, and a toothbrush, floss, and fluoride toothpaste for toothbrushing prior to examinations (5 during the study) Post‐op instructions: No chewing or brushing after application, no eating of hard food till next day |
|
| Outcomes | Reported at 2 years follow‐up: DMFS (all), DMFS (1stm), increment (CA/CA+NCA)cl (E/U) | |
| Notes | Baseline characteristics (dmft/DMFT/age) balanced. Surfaces affected: NR (dmft = 4.4/ DMFT = 0.3) Clinical (VT) caries assessment by 1 examiner; diagnostic threshold = CA and NCA; state of tooth eruption included = E/U; 10% sample re‐examined at each examination; examiner calibration (Kappa 0.90 CA/ 0.95 CA+NCA) | |
| Risk of bias | ||
| Bias | Authors' judgement | Support for judgement |
| Random sequence generation (selection bias) | High risk | Quote: "This study was a systematically randomized trial ...Then they were systematically allocated in each treatment group by the main researcher..." Quote from correspondence: "At baseline examination, children were systematically allocated in each treatment group, as follows: approximately 10 children of each classroom were taken to the examiner by the dental hygienist (she did not know the risk of caries level of the children before each examination) who organized them in a queue at random. The examiner (Pardi V) performed the examination of the first child, the main research (Tagliaferro EP) recorded the data in a specific form and classified the child in high or low caries risk, according to pre‐established criteria. After that, each classified children were allocated in the Control, Varnish or Sealant group in this sequence" Comment: Alternation used to generate sequence |
| Allocation concealment (selection bias) | High risk | Quote from correspondence: "The same researcher did the allocation and applied the sealants. Also, the non‐random method used for allocation would not allow for allocation concealment" |
| Blinding of participants and personnel (performance bias) All outcomes | High risk | No placebo varnish described |
| Blinding of outcome assessment (detection bias) All outcomes | Low risk | Quote: "...the calibrated dentist was not aware of group assignments during evaluations" Quote from correspondence: "The examiner did not see the records/documents used for recording the interventions in each child" Comment: Blind outcome assessment |
| Incomplete outcome data (attrition bias) All outcomes | Low risk | Overall drop‐out for length of follow‐up: 17% in 2 years. Drop‐outs by group: 19/109 2FV, 19/110 2NT (17.4%, 17.3%). Reason for losses: Moving out and refusing final examination (NR by group) Comment: Numbers lost were not unduly high for the length of follow‐up, were reported by group, and showed no differential losses between groups. The reasons reported for missing data are acceptable (although unclear if balanced) between groups. Caries data seem to pertain to participants present at final examinations |
| Selective reporting (reporting bias) | Low risk | Outcomes reported: 1stm ODMFS increment ‐ (CA/NCA) (E+U), at 2 years follow‐up; drop‐outs Comment: Trial protocol not available. All pre‐specified outcomes (in Methods) were reported and were reported in the pre‐specified way |
| Baseline characteristics balanced? | Low risk | Prognostic factors reported: DMFT: 0.26 (0.58) FV, 0.35 (0.67) NT. dmft: 4.28 (2.54) FV, 4.53 (3.0) NT; mean age: 7.0 (0.7) years (all groups) Comment: Initial caries appears balanced between groups |
| Free of contamination/co‐intervention? | Low risk | Comment: No apparent co‐intervention or contamination |