Bal 2015.

Study characteristics
Methods	Study type: RCT (split‐mouth design, 5 groups) Duration of trial: not mentioned in the study Duration of follow‐up: 3 months
Participants	Setting: Periodontology Department of Gulhane Military Medical Academy, Ankara, Turkey Inclusion criteria: 19 to 60 years of age, being in good systemic health, having 2 or more teeth showing hypersensitivity to air blast in each of 4 quadrants, good oral hygiene, and agreeing to 3‐month follow‐up Exclusion criteria: benign or malignant pathological oral lesions, chronic disease, chronic medication use, caries in selected or neighbouring teeth, cracked enamel, orthodontic appliances, restorations, congenital enamel and/or dentine defects, history of vital bleaching, periodontal disease, periodontal surgery or hypersensitivity treatment within the past 6 months, non‐surgical treatment of periodontal disease within the past 3 months, use of dentifrice or mouthwash containing a desensitizing agent, being pregnant or lactating, use of antidepressants or analgesics, and allergy to any of the content of the treatment Total number: 21 participants with 156 teeth Age range: 19 to 60 years Sex (M/F): 5/16
Interventions	After giving oral hygiene education at the first examination, the 4 mouth quadrants of each patient were randomized to apply 1 of the 4 study treatments. A randomly selected tooth in 1 of the quadrants was defined as the control. In each patient, a randomly selected quadrant was given 1 session of 1 of the following treatments: Group 1: (n = 41 teeth): diode laser (25 mW, 2 J/cm2, 685 nm, 100 s, 1 cm2 area). The laser dosage applied to each tooth was 4 J/cm2 for a pre‐determined time of 2 minutes, according to calibration of the laser device. The laser was applied at a distance of 2 mm from the dental outer surface Group 2: (n = 22 teeth): placebo. Physiological saline solution
Outcomes	Sensitivity to thermal (air) stimulus was recorded before and immediately post‐treatment, and on days 10, 30, 60, and 90 post‐treatment (VAS score)
Notes	Sample size calculation: not mentioned in the study Source of funding: none Ethics approval: quote: "Study protocol and consent forms were approved by the Institutional Ethics Committee of Gulhane Military Medical Academy (protocol number: 10‐1539)" Informed consent: quote: "All patients were thoroughly informed about the treatment plan, possibilities of discomfort, and risks. Written informed consent was obtained from all participants" Adverse events: quote: "One‐time application of either a 685 nm low‐level laser, or DP containing 8% arginine‐calcium carbonate, reduced DH both immediately and over the long term was performed without any adverse reactions"
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	Insufficient information provided
Allocation concealment (selection bias)	Unclear risk	Insufficient information provided
Blinding of participants and personnel (performance bias) All outcomes	High risk	Placebo was used for the control tooth, however, placebo was of different material/content. This is inadequate and the patients are likely be aware of the treatment received in each site due to the differences in perception. The outcome is likely to be influenced by incomplete blinding
Blinding of outcome assessment (detection bias) All outcomes	High risk	Lack of blinding of participants can lead to high risk for detection bias when reporting pain level
Incomplete outcome data (attrition bias) All outcomes	Low risk	Quote:"All the patients completed the 90‐day study period"
Selective reporting (reporting bias)	Low risk	All intended outcomes were reported in the study
Other bias	Low risk	No other sources of bias were identified Sample size calculation was not described in the study