Wadia 2016.

Study characteristics
Methods	Design: Uncontrolled experimental study Recruitment: Dental hospital staff were recruited – not specified how Setting: Dental hospital, UK Study start date: April 2015; Study end date: December 2015
Participants	Total N: 20 (18 of the 20 attended the reassessment visit) Inclusion criteria: 18 ‐ 65 years old Systemically healthy Smoked at least 10 cigarettes per day for at least 5 years had at least 24 natural teeth (excluding third molars) and had no probing pocket depths over 4 mm at any site did not wish to quit Exclusion criteria: Participants were excluded if they had a systemic condition known to exacerbate or modulate periodontitis (for example, diabetes) antibiotics had been taken in the previous 3 months anti‐inflammatory drugs or other medication likely to affect the periodontal tissues were taken routinely if they were pregnant or a nursing mother % women, age, cpd and FTND: not specified. Motivated to quit: enrolled people who smoke who did not intend to quit smoking, but were prepared to attempt to substitute smoking with the use of e‐cigarettes for 2 weeks E‐cigarette use at baseline: not specified
Interventions	EC: Refillable Participants provided with a blu PROTM e‐cigarette kit (Electric Tobacconist®), an extra bottle of blu PRO Tobacco™ e‐Liquid (Electric Tobacconist) and written instructions. The e‐Liquid was Classic Tobacco‐flavoured and contained 18 mg of nicotine (medium strength). The participants agreed to substitute their regular smoking habits with the use of e‐cigarettes for 2 weeks. They were asked to make a note of any cigarette smoking during the 2 weeks if complete abstinence was unsuccessful
Outcomes	2 weeks Adverse events and biomarkers: adverse effects Other outcomes measured: Cigarette use Dental outcomes
Study funding	Not specified
Author declarations	Not specified
Notes
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	High risk	No randomization
Allocation concealment (selection bias)	High risk	No randomization
Incomplete outcome data (attrition bias) All outcomes	Low risk	2 lost to follow‐up
Selective reporting (reporting bias)	Low risk	All expected outcomes reported