Zhan 2012.
| Methods | Trial design: parallel (2 arms) Location: paediatric dental clinic in San Francisco, USA Number of centres: 1 Recruitment period: January 2007 to January 2008 |
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| Participants | Inclusion criteria: healthy children aged 6 to 35 months; mothers using the wipes were primary caregivers (> 8 hours per day); minimum of one active caries lesion within a year Exclusion criteria: oral or systemic diseases; mother or child had taken antibiotics (or other medication which may potentially affect oral flora) in the previous 3 months Baseline caries: (dmfs > 0) Gp A: 2; Gp B: 1 Age at baseline (months): Gp A: mean 16.7 (SD 8.6); Gp B: mean 17.9 (SD 8.6) Gender: Gp A: 64% male; Gp B: 59% male Any other details of important prognostic factors: 80% of the population attending this clinic were of low socioeconomic status Number randomised: 44 (Gp A: 22; Gp B: 22) Number evaluated: 44 (Gp A: 22; Gp B: 22) (there were 2 drop‐outs in Gp A and 5 in Gp B but all participants were analysed on an intention‐to‐treat basis, and imputation procedure is clearly stated) |
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| Interventions |
Comparison: xylitol wipes versus placebo wipes Gp A (n = 22): mothers used two wipes to clean the teeth and gums three times per day (in addition to their normal toothbrushing) (total dose = 4.2 g xylitol per day) Gp B (n = 22): as above but without xylitol Duration of treatment: 1 year |
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| Outcomes |
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| Notes | Sample size calculation: based on previous study and on maternal microbial transmission rather than on caries Adverse effects: none observed Funding source: "This research project was supported by the California Society of Pediatric Dentistry Foundation, a Graduate Scientific Research Award from American Academy of Pediatric Dentistry, and NIH/NIDCR grant U54 DE019285. Xylitol and placebo wipes were provided free of charge from DR Products Inc" Declarations/conflicts of interest: the authors stated that they had no conflict of interest The study authors report a statistically significant difference in favour of the xylitol group. However, using the raw data from the study report, we did not find a statistically significant difference |
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| Risk of bias | ||
| Bias | Authors' judgement | Support for judgement |
| Random sequence generation (selection bias) | Low risk | Quote: "The participants were then randomized...using a pre‐set computer‐generated random number table" Comment: this is an appropriate method of random sequence generation |
| Allocation concealment (selection bias) | Low risk | Quote: "The groups were blinded as Groups A and B" and "Only one investigator...who was not involved in any patient contact, dental examinations, and microbiological assays, knew the group assignment" Comment: it appears that allocation was carried out remotely by an investigator who did not know into which group they were allocating participants |
| Blinding of participants and personnel (performance bias) All outcomes | Low risk | Quote: "double‐blinded" and "The placebo wipes were custom synthesized...for the study and were identical in appearance and composition" 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‐blinded" and "Only one investigator...who was not involved in any patient contact, dental examinations, and microbiological assays, knew the group assignment. All the other investigators involved in participant contact, microbiological assays, and statistical analysis were blinded" Comment: outcome assessment appears to have been adequately blinded |
| Incomplete outcome data (attrition bias) All outcomes | Unclear risk | 16% dropped out between baseline and final examination (Gp A: 9%; Gp B: 23%). Although all participants were included in the analysis on an intention‐to‐treat basis and imputation rules were clearly stated, we cannot be certain that the study is free of attrition bias |
| Selective reporting (reporting bias) | Low risk | Appropriate outcome measures were considered and reported in full, as described in the methods section |
| Other bias | Low risk | Quote: "The two dental examiners were trained by one investigator (LZ) to score caries lesions in a standard pediatric dental setting. Cross calibration on inter‐examiner reliability was performed on seven children (15% of the study population). The two examiners showed 100% agreement on caries scoring, with Kappa = 1 (P < 0.01)" Comment: we consider that the risk of differential diagnostic activity was low |
CIs = confidence intervals; DFS = decayed filled surfaces; DMFS/dmfs = decayed missing filled surfaces; DMFT = decayed missing filled teeth; Gp = group; ppm = parts per million; SD = standard deviation; SE = standard error
In the above tables, where a number appears after the 'D', this indicates the severity of the carious lesion progressing from enamel (1 to 3) to dentin (4 to 6)