Table 1.

Domains and description for the appraisal of the risk of bias for in vitro studies using Risk of Bias Assessment tool for Non-randomized Studies (RoBANS).

Domain	Description for In Vitro
Confounding variables	Selection bias caused by inadequate confirmation and consideration of confounding variables. For in vitro studies, bacteria should be used from the same strain and the same growth protocol for all experimental groups. Same experimental conditions should be guaranteed for both control and intervention groups (temperature conditions).
Selection of Bacteria	Selection bias caused by inadequate confirmation and consideration of confounding variables. For in vitro studies, selection of bacteria should be performed from commercially available strains or from biofilm samples collected from humans. In the second case, the biofilm composition should be clearly described.
Planning and Implementation of Interventions	Performance bias caused by inadequate planning and implementation of interventions. Techniques used to study the electric current effects should be adequate and well-established for the specific outcomes that studies are assessing, and their measurement protocol should be clearly described to allow for replication. Semiquantitative and/or qualitative analysis should be performed by two independent observers to ascertain interoperator reliability.
Measurements of Exposure	Performance bias caused by inadequate measurement of exposure. Measurement techniques should be adequate and well-established for the specific outcomes that studies are assessing, and their measurement protocol should be clearly described to allow for replication. Semiquantitative and/or qualitative analysis should be performed by two independent observers to ascertain interoperator reliability.
Binding Outcomes Assessment	Detection bias caused by inadequate blinding of outcome assessment. Outcome assessor and/or data analysist not blinded to group (i.e., intervention vs. control). For quantitative analyses, the blinding of outcome assessor and/or data analyst was not considered necessary. Otherwise (semiquantitative and qualitative analyses), blinding was required.
Incomplete Outcome Data	Attrition bias caused by inadequate handling of incomplete data outcome.Missing data from what is proposed in methodological section.
Selective Outcome Data	Reporting bias caused by selective outcome reporting. Evaluate whether the reported results might be selective, focusing only on positive findings while omitting negative or null results.