Table 5.

Risk of bias based on Cochrane Risk of Bias 2 [37] chart (studies [20,21,22,23,24,25,26,27,28,29,30,31,32,33]).

Study	Randomisation	Assignment to Intervention	Adherence to Intervention	Missing Outcome Data	Measurement of the Outcome	Selection of the Reported Result	Overall Risk of Bias
Sjögren et al. (2004) [21]			Use of own toothbrush for washout periods, unclear which toothbrush this was
Sharma et al. (2005) [22]			Used normal toothbrush during washout period
Strate et al. (2005) [23]			Use of own toothbrush for washout periods, unclear which toothbrush this was
Biesbrock et al. (2007) [24]
Biesbrock et al. (2008) [25]			Use of own toothbrush for washout periods, unclear which toothbrush this was
Putt et al. (2008) [26]
Klukowska et al. (2012) [27]			OR group used SmartGuide
Klukowska et al. (2013) [28]
Klukowska et al. (2014a) [29]			OR group used SmartGuide
Klukowska et al. (2014b) [30]			OR group used SmartGuide
Ccahuana-Vasquez et al. (2015) [31]				Two dropouts, both from comparator group; study underpowered?
Lv et al. (2018) [32]
Adam et al. (2020) [33]
Goyal et al. (2021) [34]			App use differed between groups

Key: Green = low-risk; orange = some concerns; red = high-risk.