Belcheva 2014.

Methods	Design: parallel‐group randomised controlled clinical trial Centres: 1 Date: May 2013 to December 2013 Setting: secondary care Operators: not reported
Participants	Setting: University Department of Paediatric Dentistry Geographical area: Bulgaria Sample: 90 participants (45 laser versus 45 drill); number of treated teeth as well as prepared dental cavities not reported Age: 6 to 12 years Sex: not reported Baseline: participants were affected by occlusal and proximal caries involving primary and permanent molar. Methods used for caries diagnosis as well as pulpal vitality testing were not described Inclusion criteria: children aged 6 to 12 years; 1 or more dentine carious lesions (D3 threshold, WHO system), without pulp involvement or pain, located on the occlusal or proximal surface of a primary or a permanent molar; signed informed consent form from parent; native language of the child Bulgarian Exclusion criteria: previous laser treatment of carious lesions prior the present study
Interventions	Intervention: Er:YAG laser: wavelength: 2940 nm pulse energy: 200 to 300 mJ/pulse (permanent teeth); 100 to 200 mJ/pulse (primary teeth) pulse duration: 250 μsec repetition rate: 20 Hz cooling method: water Control: drill in high‐speed and low‐speed dental handpieces
Outcomes	Primary outcomes Caries removal: not reported Episodes of pain: measured through a 6‐face rating scale after cavity preparation and before the restoration of treated teeth Secondary outcomes Marginal integrity of restoration: not reported Durability of restoration: not reported Recurrent caries: not reported Pulpal inflammation or necrosis: not reported Participant discomfort: children were asked to complete a questionnaire to show their acceptance level about vibration, noise, smell. In addition, discomfort factors such as laser or drill sight as well as taste experienced by children during treatment were evaluated Need for anaesthesia: not reported Operator preference/fatigue in operator: not reported Participant preference: not reported Duration of treatment: not reported
Notes	Funding: unclear
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	Comment: the methodology of random sequence generation was not mentioned Quote: "A group of ninety 6‐12‐years‐old patients ... who met the inclusion criteria and were treated at the Department of Pediatric Dentistry in Plovdiv, Bulgaria during the period May – December 2013, was randomly divided into two equal treatment groups"
Allocation concealment (selection bias)	Unclear risk	The allocation concealment was not described in the study
Blinding of participants and personnel (performance bias) All outcomes	High risk	The type of intervention does not allow the performance of blinding
Blinding of outcome assessment (detection bias) All outcomes	Unclear risk	Not reported
Incomplete outcome data (attrition bias) All outcomes	Unclear risk	The trial examined episodes of pain (but not caries removal). The study provides only descriptive results regarding pain and was thus considered unclear
Selective reporting (reporting bias)	Unclear risk	The study protocol was not available. The primary outcome caries removal was not reported
Other bias	Unclear risk	It was unclear whether the study was funded or not