Dias 2018.

Study characteristics
Methods	RCT, parallel groups Stratified by caries risk Duration of study: interim study with follow‐up after 24 months. Recall examinations performed with 3‐, 6‐, 12‐ and 24‐month intervals Setting: Paediatric Dental Unit of the University of Rio de Janeiro (Brazil)
Participants	Randomisation unit: teeth 28 children, 57 primary molars with occlusal caries in outer half dentine Age: 3–8 years; mean 6.79, SD 1.81 years Caries experience: ≥ 1 primary molar with caries into outer half dentine. Measured using dmft/DMFT; but also caries risk was measured using the cariogram. Baseline dmft/DMFT 5.56, SD 2.51; 54.4% of teeth had visible plaque Inclusion criteria: good health; occlusal cavitated caries lesion, limited to 1.5 mm in diameter and extending up to the outer half of dentine confirmed by a radiograph. When ≥ 1 tooth per child fulfilled the inclusion criteria, all received the same treatment) Exclusion criteria: the presence of cavities or restorations in other surfaces of target tooth; children with caries lesions in other teeth than the primary molars or with signs and symptoms of pulpal or periradicular pathology, including pain in any tooth; or if children were unable to co‐operate during clinical appointments
Interventions	2 treatment arms Group 1 (14 children, 29 teeth analysed): sealing caries with a flowable resin: cleaning of occlusal surface with pumice, local anaesthesia, rubber dam, 37% phosphoric acid for 15 seconds, rinsing and drying, application of adhesive system following manufacturer's instructions and light‐curing for 15 seconds, resin applied and cured for 20 seconds, occlusion checked and adjusted if necessary. Group 2 (14 children, 28 teeth analysed): PCR followed by restoration with a composite restoration and flowable resin. Protocol: cleaning of occlusal surface with pumice; local anaesthesia; rubber dam; cavity opened with high‐speed diamond bur and caries lesion completely removed at the enamel‐dentin junction, dentin caries partially removed with hand instruments until dentin started to become "firm and leathery"; 37% phosphoric acid for 15 seconds; rinsing and drying; application of adhesive system following manufacturer instructions and light curing for 15 seconds; restoration with resin until cavity was filled and cured in increments each for 20 seconds; occlusion checked and adjusted if necessary.
Outcomes	Primary outcomes Clinical success measured by USPHS criteria and radiographic evidence of caries progression Radiographic lesion progression Secondary outcomes Child anxiety using Facial Image Scale performed immediately before and directly after treatment, and presented to the children by the examiner (child pointed to the image) Registered time between time tooth was isolated with rubber dam, to the time the rubber dam was removed (in minutes) at time of treatment
Notes
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Children were randomised (quote) "by a block design using a coin tossing system." First, they were stratified in 2 clusters paired by caries risk, then each cluster was allocated to a group by tossing a coin.
Allocation concealment (selection bias)	Low risk	Children were randomised (quote) "with allocation concealment (through sequentially numbered, white, sealed envelopes)" distributed by a third investigator not involved with the clinical assessment or data analysis.
Blinding of participants and personnel (performance bias) All outcomes	High risk	Not described for participants. Treatments are different so at baseline operator could not have been blinded. However, evaluation of restoration success and radiographic change was done by blinded evaluators.
Blinding of outcome assessment (detection bias) All outcomes	High risk	Clinical outcome (quote) "conducted by an experienced examiner who was blinded to the treatment." Radiographic analysis performed by 2 trained and calibrated examiners who were blinded in relation to study groups. However, timing and anxiety performed by the clinician during treatment, and as treatments were different, the clinician could not have been blinded.
Incomplete outcome data (attrition bias) All outcomes	High risk	Few children missing, and, at 24 months, 13 participants in group 1 and 12 patients in group 2 were equal, but at 3 month is higher in control group and unclear why.
Selective reporting (reporting bias)	Low risk	All data outcomes reported.
Other bias	Low risk	No other biases detected.