Amin 2008.

Methods	Trial design: parallel group design, 3 randomly assigned treatment arms (resin‐modified glass ionomer, flowable composite, resin‐based sealant). Year the study started: no information on recruitment period Follow‐up: 24 months
Participants	Location: Egypt Inclusion criteria: children had to have 2 lower first permanent molars with at least two‐thirds of occluso‐cervical length erupted; and deep narrow central fissures and supplemental grooves with no evidence of cavitation, pre‐cavitation, or probe catching with stained fissures. Diagnosis based on clinical examination. Age at baseline: age range 7 to 10 years Gender: not detailed Baseline caries: no information on caries risk levels of the population at baseline Number randomly assigned: 45 children (15 in resin‐modified glass ionomer group; 15 in flowable composite group; 15 in resin‐based sealant group) Number evaluated: 39 children (12 in resin‐modified glass ionomer group; 14 in flowable composite group; 13 in resin‐based sealant group
Interventions	3 treatment arms: Group 1: resin‐modified glass ionomer (FUJI II LC) (no etching but GC Dentine Conditioner). Group 2: flowable composite (Tetric Flow) (etching with 37% phosphoric acid). Group 3: resin‐based sealant (Helioseal F) (etching with 37% phosphoric acid). Data from groups 2 and 3 were combined. Sealants were applied on the occlusal surfaces of sound first permanent molars. Isolation method was a rubber dam. No definite information who applied the sealants (likely a dentist). Co‐interventions: oral hygiene instructions; children continued their usual oral hygiene practices including the use of fluoridated toothpaste throughout the study
Outcomes	Sound or carious occlusal surface of molar, sealant retention status, and long‐term salivary Streptococcus mutans counts. Diagnosis was primarily visual, probing was used only to confirm diagnosis (assessment likely done by a dentist).
Notes	Inter‐evaluator consistency: no information provided Funding source: no identified funding source
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	Quote: "The children were randomly divided into three equal groups." Comment: No further information on sequence generation (no reply to request for information)
Allocation concealment (selection bias)	Unclear risk	No information provided (no reply for request for information)
Blinding? (Outcome assessors)	High risk	Comment: this domain was graded as having high risk of bias because we saw that blinding of outcome assessor in clinical trials of this nature cannot be performed, as outcome assessor can discriminate between materials after follow‐up
Incomplete outcome data? (Caries efficacy outcomes)	Low risk	Missing data: 2/15 children in glass ionomer group; and 1/15 in conventional resin group and 1/15 in flowable composite group at 12 months. 3/15 children in glass ionomer group; and 2/15 in conventional resin group and 1/15 in flowable composite group at 24 months. In total 4/45 (9%) children and 6/45 (13%) children after 12 and 24 months, respectively. Comment: Missing data were seen to be balanced in numbers across groups.
Selective reporting (reporting bias)	Low risk	Outcomes reported: Caries response, sealant retention, and long‐term salivary Streptococcus mutans counts. Comment: Pre‐specified outcomes (in methods) were reported in pre‐specified way.
Free of other bias? Comparability of the groups	Low risk	Quote: "The mean number of Streptococcus mutans colony forming units in the three groups were not statistically significant." Comment: Although the information on demographic characteristics is limited, this domain was graded low risk of bias because the information on Streptococcus mutans levels was similar across groups at baseline.
Free of other bias? Co‐interventions	Low risk	Quote: "Children received oral hygiene instructions and they continued their usual oral hygiene practices including the use of fluoridated toothpaste throughout the study." Comment: In all groups the same co‐interventions were allowed and of such quality that they were not seen to cause bias.