Arakji 2016.

Study characteristics
Methods	Study design: RCT (split‐mouth) Conducted in: Beirut, Lebanon, Faculty of Dentistry
Participants	Inclusion criteria: male patients having bilateral mandibular mesioangular impacted third molars (Pell and Gregory class II, position B) Exclusion criteria: heavy smokers (≥ 25 cigarettes), uncontrolled systemic conditions, pathologies, and infection related to the site of surgery Age: 18 to 35 Number randomised: 20 Number evaluated: 20
Interventions	Comparison: conventional techniques versus piezosurgery for bone removal Group A (n = 20 teeth) control site (conventional surgical hand‐piece, 35,000 rpm) Group B (n = 20 teeth) study site (piezosurgery, frequency was adjusted between 28 and 36 kHz and the microvibration amplitude between 30 and 60 micrometres/s) (Of note, conventional surgical handpiece was used to section the teeth in both control and test sites.) Preoperative chlorhexidine mouthwash was used by all participants. All operations were undertaken by the same surgeon under local anaesthesia consisting of 2% lidocaine hydrochloride with 1:80,000 adrenaline. Both sites were prepared with 5% povidone iodine solution.
Outcomes	Pain (VAS), trismus (IID measurement), and swelling (measured by tape length). These were evaluated on days 1, 7, and 14 postoperation. Bone density evaluated by the use of IOPA radiograph at baseline, 3, 6 months postoperation using ImageJ software. Marginal bone height along the distal aspect using cone beam computed tomography (CS 9300, Carestream, USA), which was taken immediately, 3 and 6 months postoperation
Notes	Test and control sites were compared regarding the study clinical and radiographic variables using paired t‐test. Significance level was set at the 5% level. Statistical analysis was performed using SPSS version 20.0. Sample size calculation: reported
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Quotes: "Sites were randomly selected by tossing a coin" Comment: coin‐tossing method was used
Allocation concealment (selection bias)	Unclear risk	Comment: unclear who performed the allocation and whether it was concealed from operator
Blinding (performance bias and detection bias) patient	Unclear risk	Comment: participants were treated under local anaesthetic only, therefore it is possible that they were aware of which side had the intervention due to the differences in noise levels between the piezosurgery and conventional rotary instruments
Blinding (performance bias and detection bias) assessor	Unclear risk	Comment: it is not clear who carried out the postoperative assessments
Incomplete outcome data (attrition bias) All outcomes	Low risk	All 20 participants completed the study period up to 6 months.
Selective reporting (reporting bias)	Low risk	Planned outcomes were reported.
Other bias	Unclear risk	It remains unclear how participants were recruited to the study, and it is also unclear why all the participants were male.