Holliday 2019.

Study characteristics
Methods	Design: Pilot RCT Recruitment: Recruited via the Newcastle Dental Hospital and by primary care practitioners working in the north‐east England region Setting: Dental clinical research facility (DCRF), located in the Newcastle Dental Hospital, Newcastle upon Tyne, UK. Study start date: 20 September 2016; Study end date: 31 July 2018
Participants	Total N: 80 N per arm: Intervention group: 40; Control group: 40 Inclusion criteria: Aged over 18 years old; smoker (≥10 cigarettes/day) Willing and able to come to the DCRF for the required study visits Having a minimum of 16 natural teeth (excluding third molars) Being diagnosed with periodontitis Exclusion criteria: Having used an e‐cigarette for more than 2 days in the last 30 days Infectious or systemic diseases that may be unduly affected by participation in this study Haemodynamically unstable Patients taking the medication adenosine (due to drug interaction risk) Lack of capacity to be able to consent to the research project or inability to follow study instructions, or both Participation in a dental research study within the previous 20 days Pregnant by medical history, or nursing Received any non‐surgical periodontal therapy other than a routine scale and polish in the last 6 months Currently undergoing or requiring extensive dental, orthodontic or implant treatment, or treatment for peri‐implantitis Inclusion based on specific population characteristic: Periodontitis 52.5% women; mean age 44.36; mean cpd 17.4; mean FTND 5 Motivated to quit: Not selected on motivation and not reported E‐cigarette use at baseline: Not currently using an e‐cigarette, or not having used 1 for more than 2 days in the last 30 days
Interventions	EC: Refillable All participants given standard stop‐smoking advice (10 ‐ 15 minutes in duration) and offer of referral to stop‐smoking services Intervention: given EC starter kit (Vype eTank clearomizer) and brief training on its use by a dentist. Provided with an approximately 2‐week supply of e‐liquid (20 ml) with a choice of flavor (Blended Tobacco, Crisp Mint, Dark Cherry and Vpure (flavorless)) and nicotine strength (0 mg/ml, 6 mg/ml, 12 mg/ml, 18 mg/ml) and information on where to buy more. EC intervention delivered directly following the standard stop‐smoking advice and was expected to be 10 ‐ 15 minutes in duration Control group: no further intervention
Outcomes	Months 1 and 6; Self‐report and biochemical validation of smoking status Cessation: Rates of continuous eCO‐verified smoking abstinence at 6 months were calculated following the Russell Standard (RS6) Adverse events and biomarkers: expired air CO, adverse events monitored at each study visit Other outcomes measured: Feasibility outcomes Oral health outcomes Smoking behavior outcomes comprised: self‐reported tobacco and e‐cigarette use, eCO, e‐salivary cotinine (SC), salivary anabasine (SA), FTND and Mood and Physical Symptoms Scale (MPS)
Study funding	"Richard Holliday is funded by a National Institute for Health Research Doctoral Research Fellowship (DRF‐2015‐08‐077). This paper presents independent research funded by the National Institute for Health Research (NIHR). The views expressed are those of the authors and not necessarily those of the NHS, the NIHR or the Department of Health and Social Care."
Author declarations	"The authors declare that they have no competing interests."
Notes	New for 2020 update.
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Randomization was performed using a secure password‐protected web‐based system
Allocation concealment (selection bias)	Low risk	Quote: "The randomisation allocation schedule will be generated by a statistician with no other involvement in the study to achieve concealment of allocation."
Blinding of participants and personnel (performance bias) All outcomes	High risk	Nature of study precluded blinding; different levels of support across intervention arms
Blinding of outcome assessment (detection bias) All outcomes	Low risk	Biochemical validation
Incomplete outcome data (attrition bias) All outcomes	Low risk	Attrition < 50%
Selective reporting (reporting bias)	Low risk	All prespecified outcomes are reported