Changes in Oral Health in Tobacco Cigarettes Smokers After Switching to Combustion-Free Nicotine Delivery Systems

NCT ID: NCT04649645

Last Updated: 2025-09-08

Study Results

Results pending

The study team has not published outcome measurements, participant flow, or safety data for this trial yet. Check back later for updates.

Basic Information

Get a concise snapshot of the trial, including recruitment status, study phase, enrollment targets, and key timeline milestones.

Recruitment Status

COMPLETED

Clinical Phase

NA

Total Enrollment

460 participants

Study Classification

INTERVENTIONAL

Study Start Date

2021-10-18

Study Completion Date

2024-12-19

Brief Summary

Review the sponsor-provided synopsis that highlights what the study is about and why it is being conducted.

Although the well-known detrimental effects of conventional cigarette smoking on oral health, there are still lack of evidences about the impact of less harmful alternatives (such as electronic cigarettes or heat not burn products), especially in young smokers with clinical absence of signs of moderate to severe periodontitis.

This study aims to investigate whether cigarette smokers who switch to combustion-free nicotine delivery systems (C-F NDS) undergo measurable improvements in oral health parameters and teeth appearance, comparing short- and long-term impact on periodontal health between smokers continuing with conventional cigarette smoking, those switching to combustion-free nicotine delivery systems (C-F NDS), and never-smokers.

The investigator propose a prospective, multicenter, interventional, open label, randomized, controlled, three parallel-arms study assessing oral health parameters and teeth appearance of 18 months duration.

Detailed Description

Dive into the extended narrative that explains the scientific background, objectives, and procedures in greater depth.

SMILE is an international, open label, randomized, controlled study of 18 months duration designed to assess whether cigarette smokers switching to combustion free-nicotine delivery systems (C-F NDS) will undergo measurable improvements in oral health parameters and teeth appearance as a consequence of avoiding exposure to cigarette smoke. Five countries have so far agreed to participate: Italy, Moldova, Poland, UK and Indonesia. An amendment will be submitted to the REC once the final two countries are signed up.

A volunteer population of never-smokers and regular smokers of conventional cigarettes with a clinical absence of signs of periodontitis will be recruited. Regular cigarette smokers will be randomized 1:4 ratio either continuing to smoke commercially manufactured conventional cigarettes (Study Arm A) or switching to C-F NDS (Study Arm B). Never Smokers will be assigned to Arm C.The intended minimum number of participants by the end of the study is 460.

Before randomization, all smokers will be reminded of the risks associated with smoking and will be offered a free smoking cessation program according to standard local guidelines and depending on the local availability of antismoking services. Those who decline the invitation will be eligible for recruitment into the study.

Smokers are free to voluntarily quit smoking/C-F NDS and/or withdraw from the study at any time.

Duration:

All participants will attend a total of seven clinics visits: Day -28 to Day -1 - Screening; Day 0 - Enrollment and Randomization (Visit 0); Day 14 (+/-3 days) - Baseline Visit (Visit 1); Day 90 (+/-5 days) - Visit 2; Day 180 (+/-7 days) - Visit 3; Day 360 (+/-10 days) - Visit 4; Day 540 (+/-10 days) - Visit 5.

Each participant will undergo screening within 28 days prior to Visit 0. Eligible participants will be enrolled and randomized on Visit 0. Baseline assessments will be performed at Visit 1, 14 days after Visit 0. The overall duration of study participation for each participant will be a maximum of 568 +/- 10 days.

The randomization sequence will be computer generated, with an allocation ratio of 1:4 (Study Arm A : Study Arm B; Smokers : N-C NDS users) to compensate for an estimated 25% success rate (combined smoking abstinence rate + \>90% smoking reduction rate) in the long term. The randomization scheme will be provided to clinical sites via a web-based application set up by the CRO. The staff randomizing the participant will access the web-based application when the participant is with them, entering their participant identification number, date of birth and initials into the program. The allocation will be immediately provided by the program/software.

Product use Regular smokers will continue to smoke their usual brand of conventional cigarette until Baseline on Visit 1. After Visit 1, participants on both Arms A and B will be asked to use only their assigned products ad libitum for the whole duration of the study.

Participants in Arm A will continue smoking their own conventional cigarette brand, as usual.

Participants in Arm B will have the option to try and choose among a selection of either three e-liquids or three tobacco sticks (depending on the C-F NDS they have chosen). They will also be trained and instructed on how to correctly use their chosen C-F NDS. Participants wishing to use a heated tobacco device (HTD) will receive the number of tobacco sticks per day corresponding to the number of cigarettes smoked per day at baseline. Participants wishing to use a vaping product will receive one vaping kit and supply of e-liquids of their choice enough to provide consumption in between supply visits (see Table 2); on average they will receive 4 x 10 ml refill containers per week. Free products will be supplied at each subsequent visit throughout the whole duration of the study.

Participants in Arm C will continue to not smoking or use any form of tobacco or nicotine-containing products.

A prospective monitoring of cigarette consumption, C-F NDS use, and oral hygiene routine will be carried out throughout the study with the tracker APP. Moreover, participants in Arm B will be asked to return all empty, part-used, and unused consumables (tobacco sticks, e-cigarette cartridges, e-liquid refill bottles) at each study visit.

Justification for Study Design

Participants in this study will be a minimum of 18 years of age. This is based on:

* The legal age to obtain tobacco products is 18 years
* The presence of at least 10 natural anterior permanent teeth in total (cuspid to cuspid, lower and upper jaw).

To investigate the effects of abstaining from smoking by switching in smokers with clinical absence of periodontitis, a population of both smokers who are intending to make the switch to N-C NDS and never-smokers will be recruited. By the end of the study, it is estimated that a high proportion (approx. 75%) of patients randomized in the Arm B of the study will not be able to achieve success (defined as either complete smoking abstinence or as at least 90% smoking reduction). To account for this, the C-F NDS population will be over sampled and a 1:4 randomization ratio scheme (i.e. for every patient randomized in the continue-to-smoke population, four will be randomized in the C-F NDS population) will be adopted.

It will not be possible to blind participants to the intervention they will be receiving. It will not be possible to blind trial staff when providing the interventions and collecting data. However, data analyses will be conducted blind to Study Arms allocation. All other trial staff who have access to outcome data will remain blinded until prespecified data analyses will be completed.

Conditions

See the medical conditions and disease areas that this research is targeting or investigating.

Gingivitis Periodontal Diseases

Study Design

Understand how the trial is structured, including allocation methods, masking strategies, primary purpose, and other design elements.

Allocation Method

RANDOMIZED

Intervention Model

PARALLEL

Smokers participants who were eligible and consent to take part will be randomized to either continuing smoking their own cigarette brand (Arm A) or switching to using C-F NDS (Arm B). Never-smokers participants who were eligible and consent to take part will be assigned to Arm C.

The randomization sequence will be computer generated, with an allocation ratio of 1:4 (Study Arm A : Study Arm B; Smokers : N-C NDS users) to compensate for an estimated 25% success rate (combined smoking abstinence rate + \>90% smoking reduction rate) in the long term. The randomization scheme will be provided to clinical sites via a web-based application set up by the CRO. The staff randomizing the participant will access the web-based application when the participant is with them, entering their participant identification number, date of birth and initials into the program. The allocation will be immediately provided by the program/software.
Primary Study Purpose

SCREENING

Blinding Strategy

NONE

Study Groups

Review each arm or cohort in the study, along with the interventions and objectives associated with them.

Standard Arm (Arm A)

Participant continues smoking their own cigarette brand.

Group Type ACTIVE_COMPARATOR

TOBACCO CIGARETTES

Intervention Type OTHER

Participants in Arm A will continue smoking their own cigarette brand as usual.

Intervention Arm (Arm B)

Participant switches to using C-F NDS.

Group Type ACTIVE_COMPARATOR

COMBUSTION-FREE NICOTINE DELIVERY SYSTEMS (C-F NDS)

Intervention Type OTHER

Participants in Arm B will trial and familiarize with a selection of C-F NDS in order to choose the product of their preference. They will be trained and counselled on the chosen C-F NDS. Prior to check-out, participants wishing to use a heated tobacco device will receive one kit and a full 2 weeks supply of tobacco sticks of their choice (they will receive a number of tobacco sticks per day corresponding to the number of cigarettes smoked at baseline); those wishing to use a vaping product will receive one vaping kit and a full 2 weeks supply of e-liquids of their choice (they will receive twelve 10 ml refill containers).

Control Arm (Arm C)

Participant continues to not smoking or using of any nicotine/tobacco products.

Group Type ACTIVE_COMPARATOR

NOT SMOKING

Intervention Type OTHER

Participants in Arm C will continue not smoking or use any form of tobacco or nicotine-containing products.

Interventions

Learn about the drugs, procedures, or behavioral strategies being tested and how they are applied within this trial.

TOBACCO CIGARETTES

Participants in Arm A will continue smoking their own cigarette brand as usual.

Intervention Type OTHER

COMBUSTION-FREE NICOTINE DELIVERY SYSTEMS (C-F NDS)

Participants in Arm B will trial and familiarize with a selection of C-F NDS in order to choose the product of their preference. They will be trained and counselled on the chosen C-F NDS. Prior to check-out, participants wishing to use a heated tobacco device will receive one kit and a full 2 weeks supply of tobacco sticks of their choice (they will receive a number of tobacco sticks per day corresponding to the number of cigarettes smoked at baseline); those wishing to use a vaping product will receive one vaping kit and a full 2 weeks supply of e-liquids of their choice (they will receive twelve 10 ml refill containers).

Intervention Type OTHER

NOT SMOKING

Participants in Arm C will continue not smoking or use any form of tobacco or nicotine-containing products.

Intervention Type OTHER

Eligibility Criteria

Check the participation requirements, including inclusion and exclusion rules, age limits, and whether healthy volunteers are accepted.

Inclusion Criteria

* Demonstrate understanding of the study and willingness to participate in the study by providing a signed written informed consent
* Healthy subjects, not taking regular medications for chronic medical conditions
* Adults, age at least 18 years old.
* Presence of at least 10 natural anterior teeth in total (cuspid to cuspid, lower and upper jaw).
* Presence of at least 18 'scorable' teeth with scorable facial and lingual surfaces. Teeth that are grossly carious, orthodontically banded, exhibiting general cervical abrasion and/or enamel abrasion, and third molars will not be included in the tooth count;
* Willingness and ability to comply with the requirements of the study including installing an APP on their digital device, e.g. smart phone or tablet.

For Arms A and B, subject have to be:

* Regular smokers, defined as:

* Smoked for at least five consecutive years prior to Screening.
* Smoked \>10 and \< 30 cigarettes per day (CPD).
* with an exhaled breath carbon monoxide (CO) level ≥7 ppm at Screening.
* willing to regularly use of any nicotine or tobacco product other than their own conventional cigarettes brand within 14 days prior to Screening.
* willing to change to use of study products or if randomized to Arm A continuing to use their own brand of conventional cigarettes for the whole duration of the study.

For Arm C, subjects have to be:

* Never-smokers, defined as:

* never smoked or who have smoked \< 100 cigarettes in their lifetime and none in the 30 days prior to screening.
* with an exhaled breath CO level \< 7 ppm at screening.
* willing to not smoke or use any form of tobacco or nicotine-containing products for the whole duration of the study.

Exclusion Criteria

* Pregnancy.
* Presence of extensive crown or bridge work, dental implants, and/or rampant decay (per Investigator/Examiner discretion)
* Significant oral soft tissue pathology or any type of gingival overgrowth, other than plaque-induced gingivitis and mild periodontitis (Stage I)
* Moderate to Severe Periodontitis (Stage II, III and IV) based on 2017 World Workshop on the Classification of Periodontal and Peri-Implant Diseases and Conditions, which require:

* Detectable Interdental Clinical Attachment Loss (CAL) ≥ 3 mm at ≥ 2 non-adjacent teeth.
* Buccal or Oral CAL ≥3 mm with pocketing ≥ 5 mm detectable at ≥ 2 teeth.
* Removable dentures or fixed and removable orthodontic appliance (except fixed lingual wires).
* Significant history of alcoholism or drug abuse (other than tobacco/nicotine) within 24 months prior to screening, as determined by the Investigator.
* A course of treatment with any medications or substances (other than tobacco/nicotine) which:

* interfere with the cyclooxygenase pathway (e.g. anti-inflammatory drugs including aspirin and ibuprofen) within 3 days prior to each visit.
* are known to have antibacterial activity (e.g. antibiotics) within 7 days prior to each visit.
Minimum Eligible Age

18 Years

Eligible Sex

ALL

Accepts Healthy Volunteers

Yes

Sponsors

Meet the organizations funding or collaborating on the study and learn about their roles.

University of Catania

OTHER

Sponsor Role collaborator

Eclat Srl.

OTHER

Sponsor Role lead

Responsible Party

Identify the individual or organization who holds primary responsibility for the study information submitted to regulators.

Responsibility Role SPONSOR

Principal Investigators

Learn about the lead researchers overseeing the trial and their institutional affiliations.

Antonio Pacino, D.D.S.

Role: PRINCIPAL_INVESTIGATOR

Addendo srl, Catania, Italy

Locations

Explore where the study is taking place and check the recruitment status at each participating site.

Addendo srl

Catania, Catania, Italy

Site Status

Countries

Review the countries where the study has at least one active or historical site.

Italy

References

Explore related publications, articles, or registry entries linked to this study.

Offenbacher S. Periodontal diseases: pathogenesis. Ann Periodontol. 1996 Nov;1(1):821-78. doi: 10.1902/annals.1996.1.1.821. No abstract available.

Reference Type BACKGROUND
PMID: 9118282 (View on PubMed)

Research, Science and Therapy Committee. Position Paper: Diagnosis of Periodontal Diseases. J Periodontol. 2003 Aug;74(8):1237-1247. doi: 10.1902/jop.2003.74.8.1237.

Reference Type BACKGROUND
PMID: 29539063 (View on PubMed)

Armitage GC. Clinical evaluation of periodontal diseases. Periodontol 2000. 1995 Feb;7:39-53. doi: 10.1111/j.1600-0757.1995.tb00035.x. No abstract available.

Reference Type BACKGROUND
PMID: 9567929 (View on PubMed)

Czesnikiewicz-Guzik M, D'Aiuto F, Deanfield JE. Understanding residual inflammatory risk sheds new light on the clinical importance of periodontitis in cardiovascular disease. Eur Heart J. 2020 Feb 14;41(7):818-819. doi: 10.1093/eurheartj/ehaa107. No abstract available.

Reference Type BACKGROUND
PMID: 32058578 (View on PubMed)

Armitage GC. Periodontal infections and cardiovascular disease--how strong is the association? Oral Dis. 2000 Nov;6(6):335-50. doi: 10.1111/j.1601-0825.2000.tb00126.x.

Reference Type BACKGROUND
PMID: 11355266 (View on PubMed)

Bergstrom J. Cigarette smoking as risk factor in chronic periodontal disease. Community Dent Oral Epidemiol. 1989 Oct;17(5):245-7. doi: 10.1111/j.1600-0528.1989.tb00626.x.

Reference Type BACKGROUND
PMID: 2791514 (View on PubMed)

Bergstrom J, Preber H. Tobacco Use as a Risk Factor. J Periodontol. 1994 May;65(5):545-550. doi: 10.1902/jop.1994.65.5.545.

Reference Type BACKGROUND
PMID: 29539746 (View on PubMed)

Haber J. Smoking is a major risk factor for periodontitis. Curr Opin Periodontol. 1994:12-8.

Reference Type BACKGROUND
PMID: 8032453 (View on PubMed)

Bergstrom J. Tobacco smoking and chronic destructive periodontal disease. Odontology. 2004 Sep;92(1):1-8. doi: 10.1007/s10266-004-0043-4.

Reference Type BACKGROUND
PMID: 15490298 (View on PubMed)

Ueno M, Ohara S, Sawada N, Inoue M, Tsugane S, Kawaguchi Y. The association of active and secondhand smoking with oral health in adults: Japan public health center-based study. Tob Induc Dis. 2015 Jul 29;13(1):19. doi: 10.1186/s12971-015-0047-6. eCollection 2015.

Reference Type BACKGROUND
PMID: 26225132 (View on PubMed)

Eriksen HM, Nordbo H. Extrinsic discoloration of teeth. J Clin Periodontol. 1978 Nov;5(4):229-36. doi: 10.1111/j.1600-051x.1978.tb01916.x.

Reference Type BACKGROUND
PMID: 363748 (View on PubMed)

Christen AG. The impact of tobacco use and cessation on oral and dental diseases and conditions. Am J Med. 1992 Jul 15;93(1A):25S-31S. doi: 10.1016/0002-9343(92)90624-k.

Reference Type BACKGROUND
PMID: 1497000 (View on PubMed)

Zhu S, Melcer T, Sun J, Rosbrook B, Pierce JP. Smoking cessation with and without assistance: a population-based analysis. Am J Prev Med. 2000 May;18(4):305-11. doi: 10.1016/s0749-3797(00)00124-0.

Reference Type BACKGROUND
PMID: 10788733 (View on PubMed)

West R, Zhou X. Is nicotine replacement therapy for smoking cessation effective in the "real world"? Findings from a prospective multinational cohort study. Thorax. 2007 Nov;62(11):998-1002. doi: 10.1136/thx.2007.078758. Epub 2007 Jun 15.

Reference Type BACKGROUND
PMID: 17573444 (View on PubMed)

Polosa R, Farsalinos K, Prisco D. Health impact of electronic cigarettes and heated tobacco systems. Intern Emerg Med. 2019 Sep;14(6):817-820. doi: 10.1007/s11739-019-02167-4. Epub 2019 Aug 14. No abstract available.

Reference Type BACKGROUND
PMID: 31414334 (View on PubMed)

Polosa R, Rodu B, Caponnetto P, Maglia M, Raciti C. A fresh look at tobacco harm reduction: the case for the electronic cigarette. Harm Reduct J. 2013 Oct 4;10:19. doi: 10.1186/1477-7517-10-19.

Reference Type BACKGROUND
PMID: 24090432 (View on PubMed)

Farsalinos KE, Polosa R. Safety evaluation and risk assessment of electronic cigarettes as tobacco cigarette substitutes: a systematic review. Ther Adv Drug Saf. 2014 Apr;5(2):67-86. doi: 10.1177/2042098614524430.

Reference Type BACKGROUND
PMID: 25083263 (View on PubMed)

McNeill A, Brose L S, Calder R, Bauld L and Robson D. Evidence review of e-cigarettes and heated tobacco products 2018. A report commissioned by Public Health England.

Reference Type BACKGROUND

Papapanou PN, Sanz M, Buduneli N, Dietrich T, Feres M, Fine DH, Flemmig TF, Garcia R, Giannobile WV, Graziani F, Greenwell H, Herrera D, Kao RT, Kebschull M, Kinane DF, Kirkwood KL, Kocher T, Kornman KS, Kumar PS, Loos BG, Machtei E, Meng H, Mombelli A, Needleman I, Offenbacher S, Seymour GJ, Teles R, Tonetti MS. Periodontitis: Consensus report of workgroup 2 of the 2017 World Workshop on the Classification of Periodontal and Peri-Implant Diseases and Conditions. J Periodontol. 2018 Jun;89 Suppl 1:S173-S182. doi: 10.1002/JPER.17-0721.

Reference Type BACKGROUND
PMID: 29926951 (View on PubMed)

Lobene RR, Weatherford T, Ross NM, Lamm RA, Menaker L. A modified gingival index for use in clinical trials. Clin Prev Dent. 1986 Jan-Feb;8(1):3-6. No abstract available.

Reference Type BACKGROUND
PMID: 3485495 (View on PubMed)

Conte G, Pacino SA, Urso S, Greiling D, Caponnetto P, Pedulla E, Generali L, Consolo U, Checchi V, Gospodaru S, Bordeniuc G, Fala V, Kowalski J, Nowak M, Gorska R, Amaliya A, Chapple I, Milward M, Maclure R, Nardi GM, Polosa R. Changes in Oral Health and Dental Esthetic in Smokers Switching to Combustion-Free Nicotine Alternatives: Protocol for a Multicenter and Prospective Randomized Controlled Trial. JMIR Res Protoc. 2024 Feb 23;13:e53222. doi: 10.2196/53222.

Reference Type DERIVED
PMID: 38393754 (View on PubMed)

Conte G, Amaliya A, Gupta S, Emma R, Gospodaru S, Bordeniuc G, Fala V, Pacino SA, Urso S, Zucchelli G, Polosa R. Repeatability of dental plaque quantitation by light induced fluorescence technology in current, former, and never smokers. BMC Oral Health. 2023 Jul 13;23(1):480. doi: 10.1186/s12903-023-03154-0.

Reference Type DERIVED
PMID: 37443061 (View on PubMed)

Conte G, Pacino SA, Urso S, Emma R, Pedulla E, Cibella F, Stefanini M, Zucchelli G, Polosa R. Repeatability of dental shade by digital spectrophotometry in current, former, and never smokers. Odontology. 2022 Jul;110(3):605-618. doi: 10.1007/s10266-022-00692-x. Epub 2022 Mar 10.

Reference Type DERIVED
PMID: 35266059 (View on PubMed)

Other Identifiers

Review additional registry numbers or institutional identifiers associated with this trial.

COE1-05-SMILE

Identifier Type: -

Identifier Source: org_study_id

More Related Trials

Additional clinical trials that may be relevant based on similarity analysis.

Efficacy of an Automatic Toothbrush
NCT05594134 COMPLETED NA