Skip to main content

Table 2 Evaluation of included studies according to revised tool for assessing risk of bias in randomized trials (RoB 2)

From: What causes failure of fixed orthodontic retention? – systematic review and meta-analysis of clinical studies

  Bovali et al. 2014 [24] Gunay et al. 2016 [25] Bolla et al. 2011 [26] Årtun et al. 1997 [27] Nagani et al. 2020 [28] Bazargani et al. 2012 [29]
Random sequence generation LOW SOME CONCERNS SOME CONCERNS HIGH LOW LOW
Allocation concealment LOW LOW HIGH LOW LOW SOME CONCERNS
Blinding of participants and personnel HIGH HIGH HIGH HIGH HIGH HIGH
Blinding of outcome assessment LOW HIGH HIGH HIGH HIGH LOW
Incomplete outcome data LOW LOW LOW LOW LOW LOW
Selective reporting LOW SOME CONCERNS LOW HIGH LOW LOW
Other bias (why) Indirect reteiners were bonded with chemical curing, direct ones – with light curing, which may both influence chairtime and survival rate. Extraction had longer reteiners (to premolars) Uneven no. of participants study groups. Different bonding materials were used. Clinical procedures were performed by different clinicians. The study group has been expanded from an earlier study. In case if detachment of retainer was noticed during the visit, the subject was allowed to approach immediately for repair and bond failure was recorded in the upcoming visit. NONE
Risk of bias judgement LOW SOME CONCERNS HIGH HIGH SOME CONCERNS LOW
  Salehi et al. 2013 [30] Arash et al. 2020 [31] Scribante et al. 2011 [32] Rose et al. 2002 [33] Gelin et al. 2020 [34] Kartal et al. 2020 [35]
Random sequence generation LOW HIGH SOME CONCERNS SOME CONCERNS LOW LOW
Allocation concealment LOW SOME CONCERNS SOME CONCERNS SOME CONCERNS LOW LOW
Blinding of participants and personnel HIGH HIGH HIGH HIGH HIGH HIGH
Blinding of outcome assessment SOME CONCERNS SOME CONCERNS HIGH SOME CONCERNS SOME CONCERNS HIGH
Incomplete outcome data LOW SOME CONCERNS LOW LOW LOW LOW
Selective reporting LOW SOME CONCERNS SOME CONCERNS SOME CONCERNS LOW LOW
Other bias (why) The study included patients during growth period. The study included patients during growth period. Regression analysis was performed for statistically non-significant results. No sample size calculation. The study included patients during growth period. No data concerning drop-out is reported. NONE Patient’s age was not provided.
Risk of bias judgement SOME CONCERNS HIGH HIGH HIGH LOW LOW
  Scribante et al. 2020 [36] Sfondrini et al. 2014 [37] Sobouti et al. 2016 [38]  
Random sequence generation SOME CONCERNS LOW LOW
Allocation concealment LOW LOW LOW
Blinding of participants and personnel HIGH HIGH HIGH
Blinding of outcome assessment LOW SOME CONCERNS SOME CONCERNS
Incomplete outcome data LOW LOW LOW
Selective reporting LOW LOW LOW
Other bias (why) NONE NONE  
Risk of bias judgement LOW LOW SOME CONCERNS