Taipale 2013.
| Methods | Trial design: parallel (3 arms) Location: healthcare centres in Muurame and Korpilahti, Finland Number of centres: not stated Recruitment period: September 2004 to February 2007 |
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| Participants | Inclusion criteria: healthy child; parents willing to use the novel slow‐release pacifier and the tablet; child started receiving tablet before age of 2 months (if they did not, but the parents were motivated to remain in the study, they were offered the possibility of administering the crushed up tablet on a spoon) Exclusion criteria: not stated Baseline caries: children were aged 2 months so had no teeth and no caries Age at baseline: 1 to 2 months Gender: Gp A: 57% male; Gp B: 46% male Any other details of important prognostic factors: not stated Number randomised: 108 (Gp A: 54; Gp B: 54) Number evaluated: 62 (Gp A: 33; Gp B: 29) |
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| Interventions |
Comparison: the 3 arms were as follows: 1) probiotic bacteria (BB‐12) plus xylitol tablet via a slow‐release pacifier or a spoon (excluded) 2) xylitol tablet via a slow‐release pacifier or a spoon 3) sorbitol tablet via a slow‐release pacifier or a spoon Gp A (n = 54): one tablet (100 mg or 300 mg xylitol ‐ depending on size of pacifier) twice per day via a novel slow‐release pacifier or crushed on a spoon (total dose = 200 mg to 600 mg xylitol per day) Gp B (n = 54): as above but with sorbitol instead of xylitol Duration of treatment: tablets were given from the age of 1 to 2 months until the child was 2 years of age * Sorbitol is considered to be inert (i.e. neither causes nor prevents caries) and therefore is commonly used as a control in xylitol studies |
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| Outcomes |
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| Notes | Sample size calculation: based on microbial colonisation percentages rather than on caries Adverse effects: not reported Funding source: personal grants from: a) the Emil Aaltonen and Sohlberg Foundations; b) the Finnish Dental Society Apollonia and the Finnish Dental Association. All study materials were donated by industry but they did not provide any financial support Declarations/conflicts of interest: none reported |
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| Risk of bias | ||
| Bias | Authors' judgement | Support for judgement |
| Random sequence generation (selection bias) | Low risk | Quote: "The infants were assigned to 1 of 3 study groups by one of the authors...according to a randomization list which had been previously computer‐generated in blocks of 3" Comment: this is an appropriate method of random sequence generation |
| Allocation concealment (selection bias) | Low risk | Quote: "The infants were assigned to 1 of 3 study groups by one of the authors...according to a randomization list which had been previously computer‐generated in blocks of 3. The block randomization was prepared by a statistician with no clinical involvement in the trial. All the study personnel and participants were blinded to treatment assignment" Comment: blocks of three would mean that it was difficult to conceal the random sequence if not done properly. However, it sounds as if the statistician carried this out remotely so that there could be no foreknowledge of intervention assignment by the study personnel |
| Blinding of participants and personnel (performance bias) All outcomes | Low risk | Quote: "double‐blind" and "Test tablets of a similar size and colour were administered" and "All the study personnel and participants were blinded to treatment assignment as well as the colour code of the tablet bottles for the duration of the study" Comment: participants and personnel would not know to which group a participant was assigned |
| Blinding of outcome assessment (detection bias) All outcomes | Low risk | Quote: "double‐blind" and "All the study personnel and participants were blinded to treatment assignment as well as the colour code of the tablet bottles for the duration of the study. Only one of the authors...had the code...However, she did not participate in producing or analysing the data at any stage of the trial and had no contact with the study participants" Comment: outcome assessment appears to have been adequately blinded |
| Incomplete outcome data (attrition bias) All outcomes | High risk | 43% of randomised participants were not included in the final analysis (Gp A: 38%; Gp B: 46%). If the missing participants had a higher risk of caries in one group than the other, as the attrition rate increased, so would over/understatement of the risk ratio |
| Selective reporting (reporting bias) | Unclear risk | Adverse events should be considered an important outcome in xylitol trials, but were not considered in this study |
| Other bias | Low risk | Quote: "All children were examined by a dentist...trained specifically for the study examination" and "The intraexaminer agreement percentage at the surface level was 97.3%" Comment: we consider that the risk of differential diagnostic activity was low |