Preliminary evidence of impaired oral wound healing in e-cigarette users: a call for perioperative vaping cessation

A prospective, parallel-arm, age- and gender-matched clinical study.

To assess and compare palatal wound healing of orally and systemically healthy e-cigarette users with a matched group of non-vapers.

Included were healthy adult volunteers (18-50 years), either e-cigarette users or never smokers, who agreed to use a study-specific e-cigarette device and e-liquids, and were willing to provide consent from. Exclusion criteria were: hypersensitivity to lidocaine, ASA grade >2, recent antibiotic therapy, history of periodontal surgery, active oral lesions, and carious cavities. E-cigarette users were instructed to use the device 2 times daily for more than 1 hour each, with 20 puffs per session. Bilateral 5 mm punch biopsy wounds were made palatally opposite to the 2nd premolar, and subjects were followed up at 1, 2, 4, 7, 14 and 21 days post-operatively. Throughout this period, 3 mm punch biopsies were harvested from the right and left healing wounds at 1- and 3- weeks respectively. All surgical procedures were conducted by the same operator. Pre-wounding palatal biofilms were collected by swabs for metabolomic profiling. Wound healing was evaluated by clinical assessment, metabolite profile, histology, and immunohistochemistry to quantify the following proteins: vimentin, keratin and filaggrin.

A total of 16 individuals were recruited: 8 e-cigarette users and 8 non-vapers. The average age was 27 years, and there were 4 men and 4 women in each group. The e-cigarette group tended to show a slightly lower total score of healing index in all visits compared to the control subjects, but the differences were not statistically significant. No site exhibited suppuration at any point, and no differences between groups were observed in the parameters of granulation. However, statistically significant differences were observed between groups for bleeding and swelling (p < 0.0001 and p = 0.0083, respectively), but not for epithelialization and redness (p = 0.0834 and p = 0.0967, respectively). Pain on palpation and difficulty in achieving hemostasis were more prevalent in e-cigarette group. The metabolic analysis between week 1 and 3 revealed significantly elevated carbohydrate and lipid metabolism in e-cigarette users, while protein metabolism was over-represented in the control group. For immunohistochemistry, significantly lower scores of vimentin, keratin, and filaggrin were shown in the e-cigarette group compared to controls at 1 and 3 weeks (p < 0.05 and p < 0.01, respectively).

E-cigarettes may significantly impair oral wound healing by impacting keratinization of epithelium and modifying the metabolic composition of the oral microbiome. Therefore, vaping cannot be regarded as safe for patients undergoing oral surgery.