ISRCTN13158982.

Study name	Enhancing dental health advice
Methods	RCT Newcastle Clinical Trials Unit, UK
Participants	Estimated enrolment: 1460  1460 adult regular tobacco smokers, with 455 of those with periodontitis going into a subgroup for additional examination and analysis Inclusion criteria: A basic periodontal examination completed within the last 3 months; ≥ 18 years; current smoker Periodontitis subgroup: Minimum of 16 natural teeth; diagnosis of periodontitis stage II (or greater) Exclusion criteria: Pregnant or currently breastfeeding; enrolled in another interventional research trial; used quit‐smoking aid or reduce/quit alcohol; phaeocromocytoma, uncontrolled hyperthyroidism, extensive dermatitis/skin disorder; hypersensitivity to nicotine or any component of the study products; taking: clozapine, olanzapine, theophylline or aminophylline
Interventions	EC type not specified. The starter kit will include ten, 10 mL bottles of e‐liquid with different flavours and nicotine concentrations. Condition: Smoking cessation in dental patients with or without gum disease Arm 1: Control arm: Very Brief Advice (VBA) 1. VBA is usual care for smokers in dental settings usually following the 3As: Ask, Advise, Act technique. This will signpost participants to a GP, pharmacy or stop‐smoking service (SSS).  2. Participants in the control group will be free to use NRT or ECs as they wish but these will not be provided by the dental professional. 3. Conducted at baseline visit, only a 5‐minute intervention 4. Patients will be followed up for up to 12 months from baseline. Arm 2: Nicotine Replacement Therapy (NRT) 1. If a participant is randomised to a NRT arm, a trained dental professional will provide a single‐visit behavioural support intervention including the offer of NRT. 2. 12‐week course of combination NRT (patch plus faster acting form such as chewing gum or lozenge), in line with current recommendations 3. Duration will be 12 weeks if a participant wants to continue NRT after initial 4‐week supply. 4. Participants will be followed up for up to 12 months from baseline.  Arm 3: E‐cigarette (EC) Receive the same behavioural intervention as the NRT group along with EC starter kit. The starter kit will include ten, 10 mL bottles of e‐liquid with a choice of one of four packages of flavour and nicotine concentrations. 2. Participants will be expected to source their own supply of e‐liquid after the initial supply and advice will be given as to where to source suitable MHRA registered products. 3. Duration will vary depending on use of EC. 4. Participants will be followed up for up to 12 months from baseline.
Outcomes	Baseline to 12 months. Primary outcome measure: Biochemically verified smoking abstinence 6 months after randomization using a carbon monoxide monitor Secondary outcome measures: 1. Continuous biochemically verified smoking abstinence is measured using exhaled Carbon Monoxide (eCO) at 12 months. 2. Nicotine dependence is measured using Fagerstrom Test for Nicotine Dependence (FTND) at baseline and 6 months 3. Cigarette withdrawal symptoms are measured using Mood and Physical Symptoms Scale (MPSS) at baseline and 6 months. 4. Quality of life related to oral health  5. Oral health is measured using number of teeth at baseline and 6 months. 6. Health economic evaluation For periodontitis subgroup only: Periodontal health is measured. See study for more detail.
Starting date	Study start date February 2022. Estimated completion date: March 2025
Contact information	Dr Richard Holliday, richard.holliday@newcastle.ac.uk
Notes	New to 2022 update