Lund 2013.

Study characteristics
Methods	Study type: RCT (split‐mouth design) Duration of trial: not mentioned in the study Duration of follow‐up: 3 months
Participants	Setting: Dental College at Federal University of Pelotas, Brazil Inclusion criteria: aged between 18 to 60 years, good health conditions, symptoms elicited by cold air, no periodontal surgery in the last 6 months, no use of desensitizing agents in the last 6 months, no use of analgesics and/or anti‐inflammatory medicines, no orthodontic treatment, absence of excessive gingival inflammation and the presence of, at a minimum, 2 teeth with dentine hypersensitivity Exclusion criteria: any other possible causes of sensitivity such as pulpitis, failed restorations, premature contacts, attrition, abrasion, occlusal stress or periodontal disease Total number: 13 participants enrolled and completed Age range: 19 to 58 years Sex (M/F): 5/8
Interventions	Group 1: diode low‐level laser group Details: infrared diode low‐level laser treatment (Biowave Dual – Kondortech, class IV = 780 nm) consisted of 3 sessions of application on the teeth, at intervals of 72 hours. The protocol was followed by 4 punctual applications of 10 s each, 3 at the cervical zone (mesio‐buccal, the bucco‐lingual midpoint and disto‐buccal) and 1 at the root apex with an applied dosage of 5 J/cm which represented the effective optic potency of 20 mW at the entry of the laser equipment Group 2: carbomer 940 gel (placebo)
Outcomes	Exposure time to air blast (VAS) at baseline, 5 minutes after the execution of the last session of treatment and after 7, 15, 30, and 90 days
Notes	Baseline characteristics: 1. using an evaporative stimulus (with a dental air syringe) that was applied 2 cm distant from the hypersensitive area for 60 s, with a right angle to the buccal site of the assigned teeth, whilst adjacent teeth were isolated with cotton rolls, until the patient raised his or her hand to indicate the occurrence of sensitivity; 2. soon after pain was detected, the stimulus was interrupted and the Exposure Time to Air Blast (ETAB) was noted; 3. after the stimulus, the patient was asked to mark the intensity of pain on a VAS, which was marked on the left end 'no pain' and on the right end 'extreme pain' Sample size calculation: not mentioned in the study Source of funding: not mentioned in the study Ethics approval: quote: "Ethics Committee of the Dental College at Federal University of Pelotas, RS, Brazil (Reference #046/2003)" Informed consent: quote: "Patients that met all of the inclusion criteria signed consent forms before entering the trial" Adverse events: none
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	Insufficient information provided Quote: "the teeth were randomly divided into one of three"
Allocation concealment (selection bias)	Unclear risk	Insufficient information provided
Blinding of participants and personnel (performance bias) All outcomes	High risk	Lack of use of placebos might lead to performance bias Comment: the patients are likely to be aware of the treatments received due to the differences in perception of each treatment. The outcome is likely to be influenced by lack of blinding
Blinding of outcome assessment (detection bias) All outcomes	High risk	Lack blinding of participants can lead to high risk for detection bias when reporting pain level
Incomplete outcome data (attrition bias) All outcomes	Unclear risk	Insufficient information provided
Selective reporting (reporting bias)	Low risk	The intended outcome (pain) was reported
Other bias	Low risk	No other sources of bias were identified Sample size calculation and source of funding were not mentioned in the study