Yilmaz 2011a.

Study characteristics
Methods	Study type: RCT (split‐mouth, 3 groups) Duration of trial: not mentioned in the study Duration of follow‐up: 3 months
Participants	Setting: Department of Periodontology, Near East University, Turkey Inclusion criteria: 3 or more hypersensitive teeth in different quadrants Exclusion criteria: carious lesions on the selected or neighboring teeth, defective restorations, any professional desensitizing therapy on the selected teeth during the last 6 months, use of desensitizing toothpaste in the last 3 months; being under analgesics/anti‐inflammatory drugs at the time of the study, pregnancy or smoking Total number: 51 participants with 174 teeth enrolled and completed Age range: 18 to 60 years (mean age: 44 years) Sex (M/F): 22/29
Interventions	Group 1: GaAlAs laser (wavelength: 810 nm; output: 8.5 J/cm2; duration: 60 s) Details: in the diode laser group, sensitive teeth were irradiated with the GaAlAs laser (LaserSmile, Biolase Technology, Irvine, CA, USA) using 810 nm continuous waveform at 8.5 J/cm2 energy density Group 2: Er,Cr:YSGG laser (wavelength: 2780 nm; output: 0.25 W; duration: 30 s) Details: in the Er,Cr:YSGG laser group, sensitive teeth were irradiated at 2780 nm with Er,Cr:YSGG laser (Waterlase MD, Biolase Technology, Irvine, CA, USA) in the hard tissue mode with the MZ6 sapphire tip (600 μm diameter, 6 mm length) using non‐contact mode at an energy level of 0.25 W, repetition rate of 20 pulses/s and pulse duration of 140 μs, 0% water and 10% air. Treatment time was 60 s for GaAlAs laser and 30 s for Er,Cr:YSGG laser by scanning the cervical part in an overlapping pattern Group 3: no treatment
Outcomes	Responses to air blast stimuli (VAS) at baseline, and immediately, 1 week, 1 month, 3 months after intervention
Notes	Baseline characteristics: the vitality of all experimental teeth was controlled at the beginning and end of the trial by means of an electric pulp tester (Digitest, Parkel, NY, USA). For 4 weeks before treatment, all patients were enrolled in an oral hygiene programme and received oral hygiene instructions on 2 appointments as well as professional tooth cleaning according to individual needs. Prior to the application of lasers in all groups,dentine hypersensitivity was assessed by an evaporative stimulus. A strong air blast from a dental syringe was directed to the exposed cervical area for 3 s at a distance of 1 cm and at right angle to the buccal site of the assigned teeth, whilst adjacent teeth were isolated with cotton rolls. Air stimulus time was controlled by a chronometer and the distance was measured by a UNC‐15 periodontal probe (Hu‐Friedy, Chicago, IL, USA). Patients were asked to record their overall sensitivity by marking a point on a 10 cm VAS, anchored at each end by the phrases 'no pain' and 'unbearable pain'. All stimuli were given by 1 operator in the same dental chair with the same equipment yielding similar air pressure (55 to 60 psi) and air temperature (21 to 22℃) each time Sample size calculation: quote: "A minimum clinically significant difference in VAS scores of 0.6 was determined from the available literature on DH. The power analysis was conducted based on this minimum clinically significant difference in VAS scores, using alpha at level 0.05, at 80% power and a σ of 1.16. On the basis of these data, the number of patients required to be enrolled to conduct this study was calculated as 40" Source of funding: not mentioned in the study Ethics approval: quote: "Study protocol and related consent forms were approved by our Institutional Review Board" Informed consent: quote: "After having received oral and written information about the intention and the design of the study, and having signed the informed consent form, the subjects were included in the study" Adverse events: none
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Quote: "In this split‐month study, for each patient, selected teeth were randomly assigned to Er, Cr:YSGG laser group, GaAlAs diode laser group or control group by the lottery method" Comment: adequate
Allocation concealment (selection bias)	Low risk	Author's reply: "Sealed, opaque, sequentially numbered, identical envelopes" Comment: probably done
Blinding of participants and personnel (performance bias) All outcomes	High risk	Lack of placebos might lead to performance bias Comment: the patients are likely be aware of the treatment received in each site due to the differences in perception (lasers versus no treatment).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 Quote: "The effectiveness of all treatments was assessed at four examination periods; immediately, at 1 week, 1 and 3 months after treatment by one examiner who was not aware of the type of treatment applied"
Incomplete outcome data (attrition bias) All outcomes	Low risk	No loss to follow‐up
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 Source of funding was not mentioned in the study