Electronic cigarette vapor increases Streptococcus mutans growth, adhesion, biofilm formation, and expression of the biofilm-associated genes

The effects of electronic smoking on dental caries and proinflammatory markers: a systematic review and meta-analysis

Introduction

Smoking and the use of electronic cigarettes (e-cigs) are common practices that have significant consequences for oral health. Although the negative impact of traditional tobacco products on oral tissues is widely known, the emergence of e-cigs poses a new obstacle. This review summarises existing data on the influence of e-cigs on oral health, with a specific emphasis on dental caries and pro-inflammatory agents.

Methods

A comprehensive search was conducted via PubMed, Web of Science, Embase, and Scopus to identify relevant studies published until September 2024. The structured search strategy uncovered 42 articles that were read in full text. The included articles consisted of clinical trials, observational studies, and laboratory investigations that examined the impact of e-cig aerosol on oral bacteria and pro-inflammatory markers and its potential to contribute to dental caries.

Results

The findings indicate that e-cig users may have a higher prevalence of dental caries compared with non-smokers. Most studies focusing on bacteria showed that vaping may inhibit normal flora, giving cariogenic bacteria a chance to grow more. This finding indicates a notable oral health risk associated with vaping. Meta-analyses suggest no effect of using e-cigs on the levels of TNF-α, IL-1β, IL-6, and IL-8 in saliva, even if it may affect their levels in GCF. However, in GCF, only one study reported TNF-α and IL-1β, and only two studies reported IL-6 and IL-8. Nevertheless, the effects of e-cigs on dental caries require further investigation since the data do not provide a clear picture.

Discussion

This review emphasises the necessity for ongoing research to clarify the mechanisms that cause these consequences and to guide public health policies aimed at reducing the harm caused by e-cigarettes.

Systematic Review Registration

https://www.crd.york.ac.uk/PROSPERO/view/CRD42024537910, PROSPERO (CRD42024537910).

The effect of cigarette smoking and heated tobacco products on different denture materials; an in vitro study

PURPOSE

This study compares the effect of conventional cigarette smoke versus heated tobacco on the discoloration, surface roughness, and bacterial colonization of different oral prosthesis materials.

MATERIALS AND METHODS

A total of one hundred and twenty disc-shaped samples made of four different denture base materials were prepared to represent different denture bases to assess the surface roughness and biofilm formation; group (CA): conventional heat-cured acrylic resin (Acrostone, Egypt), group (FA): flexible acrylic resin (Valplast International Corp, USA), group (TA): heat-cured acrylic resin reinforced with titanium nanoparticles (TA nanoparticles, Nanogate, Egypt), and group (PA): 3D printed acrylic resin (Nexdent, The Netherlands). Another sixty samples of artificial and 3D printed teeth were used to assess the color change: conventional ready-made acrylic resin teeth (Acrostone, Egypt) and 3D-printed acrylic resin teeth (Nexdent, The Netherlands). Each group was further divided according to the smoking method into three subgroups (n = 10): the no-smoking exposure group (C), the conventional smoking exposure group (CS), and the heated tobacco exposure group (HT). A custom-made smoking device was used to perform the experiment. Six hundred cigarettes/heets representing 30 days of medium smoking behavior (20 cigarettes/day) were used. The surface roughness of the disc-shaped samples was measured before and after the experiment using the JITAI8101 surface roughness tester (Beijing Jitai Tech Detection Device Co., Ltd, China), and the color parameters were assessed before and after the experiment using VITA Easyshade Advance 4.01 (VITA shade, VITA made, VITA).

RESULTS

The results showed that both conventional cigarette smoking and heated tobacco increased the surface roughness of the denture base disc samples. This change was statistically significant in all sample groups. Bacterial accumulation was also increased in all four denture base sample groups, with the heated tobacco causing greater bacterial accumulation than conventional cigarette smoke. Regarding the color change, conventional smoking caused a more significant color change than heated tobacco for both types of teeth used.

CONCLUSION

Both conventional smoke and heated tobacco affect dental materials adversely. Conventional cigarette smoking caused greater surface roughness and discoloration of the samples, while heated tobacco resulted in greater bacterial accumulation of study materials.

CLINICAL IMPLICATIONS

Increase dentists' and patients' awareness of the effects of different types of smoke.

E-cigarette exposure increases caries risk and modifies dental surface in an in vitro model

OBJECTIVE

Electronic cigarettes have become increasingly popular and can deliver nicotine at levels comparable to traditional tobacco cigarettes. However, the potential adverse effects of these alternative smoking devices on dental health remain uncertain. This study investigates changes in the cariogenic potential of tooth surfaces and analyzes alterations in the chemical composition of aerosols generated from sweet-flavored e-liquids used in electronic cigarettes.

DESIGN

Smoking was simulated using an electronic-cigarette testing machine. Eighty specimens of enamel, dentin and root dentin were divided in two groups according smoking: pre-smoke and post-smoke. The response variables were Microhardness (n=10), SEM (n=5) and FTIR (n=5). E-liquid was analyzed pre-smoke and post-smoke by HPLC-UV/Vis. Data were analyzed by one-way ANOVA and Tukey's tests, with a significance level of 5 %. SEM, FTIR and HPLC-UV/Vis data were qualitatively analyzed.

RESULTS

Enamel exhibited higher microhardness values before and after smoking, with all substrates showing significant microhardness reduction after smoking. All dentin specimens presented standard dentinal tubules, and post-smoke enamel prisms appeared disorganized with various orientations. The specimens' chemical constituents remained stable. Dentin and root dentin post-smoke, carbonate band intensity decreased. There was a thermal degradation of e-liquid products and the formation of new compounds post-vaporization.

CONCLUSIONS

E-cigarette smoking reduces the microhardness of enamel, dentin, and root dentin, alters enamel morphology, induces chemical interactions between e-liquid and tooth tissues, and may increase the risk of cariogenic potential.

Immunological Effects of Electronic Cigarette Use: A Review of Current Evidence

Electronic cigarettes (EC) have emerged as a popular alternative to traditional tobacco products, but their impact on immune function has raised significant health concerns. This review explores the immunological effects of EC exposure, focusing on innate and adaptive immune responses. Electronic cigarette aerosol (ECA) induces widespread inflammation. These changes compromise immune cell function, impairing neutrophil chemotaxis, phagocytosis, and oxidative burst while increasing macrophage and dendritic cell recruitment and activation. ECA also disrupts epithelial barriers, increasing susceptibility to bacterial and viral infections. Studies show enhanced biofilm formation in bacteria such as Staphylococcus aureus and Streptococcus pneumoniae and impaired antiviral responses against pathogens like influenza A and SARS-CoV-2. Additionally, EC exposure modulates adaptive immunity, affecting T and B cell function and increasing systemic inflammatory markers. The long-term consequences of these immunological disruptions include heightened risks for chronic inflammatory diseases, respiratory infections, and potentially autoimmune conditions. The widespread adoption of EC, particularly among younger users, poses a growing public health challenge. As the popularity of vaping continues to rise, these immunological disruptions could result in increased healthcare burdens in the future, with higher rates of infections, chronic inflammatory diseases, and immune system-related disorders among those who begin using e-cigarettes at a young age. Understanding the full scope of EC-related health risks is essential for informing public health policies and protecting future generations from the potential long-term effects of vaping.

Effect of cannabidiol (CBD), a cannabis plant derivative, against Candida albicans growth and biofilm formation

HIGHLIGHTS

Cannabidiol (CBD) decreases the growth of C. albicans. CBD inhibits the yeast-to-hyphae transition. CBD reduces biofilm formation by C. albicans. CBD induces C. albicans death through necrosis.

The Impact of E-Cigarettes on Oral Health-A Narrative Review

Background/Objectives: Electronic cigarettes (e-cigarettes) are commonly used by former smokers as an alternative product to conventional cigarettes and also by young adults and adolescents to deliver nicotine. E-cigarettes are thought to be a less harmful and more socially acceptable alternative to tobacco smoking; however, their long-term effects on health, including oral health, are currently unknown. Methods: A literature search for relevant papers indexed in the literature from 2016 to 2023 was conducted using the PubMed, Scopus, and Google Scholar databases. In our paper, we included clinical trials and both in vivo and in vitro research concerning the impact of e-cigarettes on oral health. Results: E-cigarettes impact the oral cavity, which is directly exposed to inhaled chemicals present in e-cigarette aerosols. The use of e-cigarettes has been linked to teeth discoloration and dental caries, promoting the development of periodontal diseases and causing oral mucosa lesions, including oral cancer. E-cigarette aerosols might also negatively affect the oral microbiome by suppressing the growth of commensal bacteria and increasing the population of bacteria responsible for developing numerous oral disorders. E-cigarettes also impact saliva composition and its properties, including reducing saliva's antibacterial and antioxidant properties, which may subsequently lead to the promotion of oral diseases. Conclusions: The outcomes suggest that e-cigarette usage may cause the development of oral diseases, however further longitudinal studies of a larger and homogenous group of e-cigarette users are required.

The Effect of New Trend Electronic Cigarettes on Dental Caries in Relation to Glucosyltransferase B and Secretory Immunoglobulin A (A Case-control Study)

Electronic cigarettes (vapes) are actively used, and their use is growing globally, especially among young people. Its spread is rapid due to the presence of unproven rumors that it is used to treat smoking addiction as it aids in smoking cessation. However, E.C has a negative impact on dental health by affecting the oral microbiome and salivary components. The goal of this study was to evaluate the impact of electronic cigarettes on dental caries in relation to glucosyltransferase B and secretory immunoglobulin in the saliva of electronic cigarette users. Ninety active males were divided into two groups: 45 electronic-cigarette smokers in addition to 45 non-electronic-cigarette smokers as a control group. An oral examination was performed on the studied groups, and decayed missing filling tooth surfaces (DMFS) were documented. Additionally, unstimulated saliva was collected to evaluate salivary glucosyltransferase B and secretory immunoglobulin A by using a sandwich enzyme-linked immune-sorbent assay (ELISA). The obtained outcomes showed that decayed, missing, and filled Surfaces values(DMFS), salivary glucosyltransferase B, and salivary secretory immunoglobulin A were greater in the study group than in control group. Additionally, a correlation between glucosyltransferase B, secretory immunoglobulin A, and DMFS was positive and significant. It was concluded that e-cigarettes may have an effect on saliva components and dental caries.

The use of electronic cigarettes and other tobacco products among university students and their potential relationship with oral health: A cross-sectional study

BACKGROUND

The aim of this study was to evaluate oral alterations among university students and explore possible associations with tobacco consumption in its various forms.

METHODS

A cross-sectional study was conducted in 2 phases: the first phase involved administering an electronic questionnaire to participants determine the prevalence of tobacco use and the second phase involved a physical examination of the participants. The participants were grouped on the basis of their reported habits and compared using statistical analysis (P < .05).

RESULTS

Of the 620 participants, 57.1% reported using tobacco in some form, with 47.4% reporting electronic cigarette (e-cigarette) use. In the clinical phase, comparing the presence of oral changes in tobacco users vs nonusers, e-cigarette users had a higher proportion of white-spot caries lesions (P = .041) and gingivitis (P = .012). When e-cigarette use was combined with other forms of tobacco use, additional oral changes were more prevalent, including coated tongue and nicotinic stomatitis (P < .05).

CONCLUSIONS

The use of alternative forms of tobacco consumption is common among university students, with e-cigarette use being the most prevalent form, and may lead to detrimental effects on the oral cavity, such as caries and gingivitis, particularly when used in conjunction with other tobacco products.

PRACTICAL IMPLICATIONS

The use of tobacco in alternative forms, such as e-cigarettes, can affect oral health directly or indirectly. Dentists should be familiar with the characteristics of this population and the potential oral repercussions associated with tobacco use to address the impact on health and raise awareness of the associated risks.

Dental plaque quantitation by light induced fluorescence technology in exclusive Electronic Nicotine Delivery Systems (ENDS) users

OBJECTIVES

In comparison to conventional combustible cigarettes, Electronic Nicotine Delivery Systems (ENDS) including both e-cigarettes (ECs) and heated tobacco products (HTPs) significantly reduce exposure to toxic chemical emissions. However, their impact on dental plaque remains unclear. This study measures dental plaque in ENDS (ECs and HTPs) users using quantitative light-induced fluorescence (QLF) technology, comparing them with current, former, and never smokers.

METHODS

This cross-sectional study compared dental plaque measurements using QLF technology (Q-ray cam™ Pro) among current smokers (≥10 cigarettes/day), former smokers (quit ≥6 months), never smokers, and exclusive ENDS users (quit ≥6 months). Dental plaque measurements were expressed as ΔR30 (total area of mature dental plaque) and ΔR120 (greater plaque thickness/maturation-calculus). The Simple Oral Hygiene (SOH) score was calculated by the QLF proprietary software. Statistical analyses including ANCOVA was performed by R version (4.2.3) with p < 0.05.

RESULTS

A total 30 smokers, 24 former smokers, 29 never smokers, and 53 ENDS users were included. Current smokers had significantly higher ΔR30 and ΔR120 values compared to other groups (p < 0.001). ENDS users showed plaque levels similar to never and former smokers (p > 0.05) but significantly lower than current smokers (p < 0.01). Although ENDS users showed a lower SOH score than smokers, this difference was not statistically significant. Daily toothbrushing and mouthwash usage were significant covariates.

CONCLUSION

ENDS users exhibited reduced accumulation of dental plaque and calculus compared with current smokers.

CLINICAL SIGNIFICANCE

Exclusive ENDS use could less impact dental plaque accumulation compared to cigarette smoking. Further research is needed to confirm these findings and fully understand ENDS impact on dental plaque formation.

Clinical characteristics and caries risk assessment of tobacco heating systems smokers, cigarette smokers and non-smokers: a cross-sectional study

OBJECTIVES

The study compared clinical characteristics and caries risk assessments between tobacco heating system (THS) smokers, cigarette smokers and non-smokers.

MATERIALS AND METHODS

General data, data regarding fluoridation, smoking and dietary habits was obtained through a questionnaire. Caries experience was assessed by the DMFT index; the amount of biofilm by the Full mouth plaque score index; the amount of salivation by the quantum of stimulated salivation test; salivary pH with pH indicator strips and salivary number of S.mutans and Lactobacilli by cultivation on agar plates. The Cariogram method was used to assess caries risk.

RESULTS

No differences between the groups was detected regarding education level, average daily number of meals, fluoridation programs, systemic diseases, and caries experience. The groups significantly differed in the amount of salivary S.mutans and Lactobacilli (p < 0.001), accumulated biofilm (p = 0.034), salivation quantum (p < 0.001), and saliva pH (p = 0.009). Exposure to tobacco smoke and heated tobacco aerosol increased the accumulation of biofilm and decreased salivary pH. Smoking increased S. mutans, while THS consumption decreased salivation and Lactobacilli the most. The Cariogram analysis found no differences in chances of avoiding new caries lesions between the groups, but a significant difference in developing caries lesions due to dietary habits was detected (p < 0.001) with non-smokers having higher risk than smokers, but not than THS consumers.

CONCLUSIONS

THS and cigarette smoking were related to clinical characteristics that affect caries activity even though the caries risk assessment revealed no significant difference in the chances of avoiding new caries lesions between the groups.

CLINICAL RELEVANCE

THS and cigarette smokers could have higher caries activity than non-smokers. The clinical study protocol has been registered on ClinicalTrials.gov under the ID number: NCT06314100.

Is there evidence that e-cigarettes promote an increased risk of dental caries?

DATA SOURCES

This study was conducted on a sample of patients who attended the dental clinic at Tufts University School of Dental Medicine, between January 1, 2019 and January 1, 2022. Ethical approval was obtained before commencing the research.

STUDY SELECTION

This cross-sectional study was carried out through an electronic search of electronic records. It includes patients aged over 16 years, both electronic cigarette (e-cigarettes) users and non-users, with recorded caries risk assessments. Patients with a history of recreational drug use or lacking a caries diagnosis were excluded. The Caries Management by Risk Assessment (CAMBRA) was utilized to indicate and classify caries risk.

DATA EXTRACTION AND SYNTHESIS

Descriptive statistics, multivariate and bivariate analyzes were used to assess the relationship between use of e-cigarettes and caries risk level. SPSS software, Version 26 (IBM) was used in the analysis with significance level set at α = 0.05.

RESULTS

Out of a total of 13,216 patients included in the research, 13,080 (99.3%) self-declared as non-users of e-cigarettes, and 136 (0.69%) were e-cigarette users. There was a statistically significant difference (P < 0.001) in caries risk levels between e-cigarette users (6.6% low, 14.3% moderate, and 79.1% high caries risk level) and control group (14.5% low, 25.9% moderate, and 59.6% high caries risk level).

CONCLUSIONS

The study provides evidence supporting the notion that e-cigarette users exhibit a high level of caries risk.

The Role of Electronic Cigarettes in Dental Caries: A Scoping Review

Dental caries, a predominant childhood and adolescence affliction, has numerous factors implicated in its pathogenesis. Electronic cigarettes (ECs) have recently gained popularity among the younger population. Various factors, such as the EC liquid composition and aerosols, are associated with the development of dental caries. This review explains numerous EC-related factors which may lead to dental caries. An electronic search was conducted in Medline (Pubmed), Scopus, and Embase databases to evaluate the original research investigating the role of ECs in developing dental caries. About 12 included studies in the review indicated that factors such as the composition of e-liquids and aerosols are significant in the progression of dental caries. Specifically, cariogenic sugars such as sucrose, fructose, glucose, aldehydes, and flavors such as menthol, cinnamon, and strawberry in the e-liquids contribute to dental caries. They are toxic to oral commensals such as Streptococcus gordonii, Streptococcus mitis, Streptococcus intermedius, and Streptococcus oralis and promote the proliferation of cariogenic pathogens such as Streptococcus mutans (S. mutans) which causes dental caries. However, further validation of the effects of ECs on the development of dental caries is warranted through clinical trials.

The risk profile of electronic nicotine delivery systems, compared to traditional cigarettes, on oral disease: a review

The use of electronic nicotine delivery systems (ENDS) has exploded, especially among teenagers and new smokers, amid widespread awareness of the dangers of traditional tobacco and restrictions on smoking. However, the risk effects of ENDS on physical health, especially oral health, are still ambiguous. The purpose of this study was to review the available evidence on risks of ENDS on oral health, and compares the differences between ENDS and traditional cigarettes. For heavy smokers, transferring the addiction of tobacco to ENDS can be less harmful to periodontal condition and physical health but is not completely without risk. The components of ENDS vapor have cytotoxic, genotoxic, and carcinogenic properties, and its usage may be associated with a wide range of oral health sequelae. The chemicals in ENDS increase the susceptibility to tooth decay, increase the risk of periodontal disease, peri-implant, and oral mucosal lesions. Nicotine aerosols from ENDS can be a potential risk factor for oral cancer due to the presence of carcinogenic components. Compared to smoking traditional cigarettes, the harm associated with ENDS use may be underestimated due to the reduced ability to control vaping behavior, ease of ENDS access, fewer vaping area restrictions, and better taste. Currently, the available evidence suggests that ENDS may be a safer alternative to traditional tobacco products. Though most oral symptoms experienced by ENDS users are relatively mild and temporary compared to traditional cigarettes, the dangers of ENDS still exist. However, further research with longer follow-up periods is required to establish the long-term safety of ENDS.

A Systematic Review of the Literature Examining the Effects of Cigarette Smoke and e-Cigarette Vapor on the Virulence of Human Pathogenic Bacteria

The bioactive chemicals in cigarette smoke (CS) and e-cigarette vapor (EV) may affect pathogenic bacteria in the nasopharyngeal microflora, which may have implications on the pathophysiology of respiratory infections in cigarette smokers and e-cigarette users. In this systematic review, we seek to synthesize the research evidence supporting this hypothesis. To address the central research question, "what is known from the published, peer-reviewed literature about the effects of cigarette smoke or e-cigarette vapor exposure on the physiology of human pathogenic bacteria?", we screened the PubMed®, Web of ScienceTM, and ScienceDirect databases for reports examining the virulence characteristics and gene expression in human pathogenic bacteria exposed to either CS or EV. The principal conclusion from our analysis is that exposure to either CS or EV induces the virulence of respiratory pathogenic bacteria in a strain-dependent manner, which may in turn facilitate respiratory infections in cigarette smokers and e-cigarette users. In addition, we present evidence that nicotine and reactive oxygen species are the main chemicals responsible for CS/EV-mediated alterations in bacterial physiology. We note limitations that this review does not examine reports describing the alterations in host respiratory physiology or nasopharyngeal dysbiosis caused by CS/EV exposure. Future research to determine whether CS/EV-mediated augmentation of bacterial virulence indeed plays a role in human respiratory tract infections is warranted.

Raffinose Inhibits Streptococcus mutans Biofilm Formation by Targeting Glucosyltransferase

Streptococcus mutans is a representative biofilm-forming bacterium that causes dental caries through glucosyltransferase (GTF) activity. Glucans are synthesized from sucrose by GTFs and provide binding sites for S. mutans to adhere tightly to the tooth enamel. Therefore, if a novel compound that interferes with GTF function is developed, biofilm formation control in S. mutans would be possible. We discovered that raffinose, an oligosaccharide from natural products, strongly inhibited biofilm formation, GTF-related gene expression, and glucan production. Furthermore, biofilm inhibition on saliva-coated hydroxyapatite discs through the reduction of bacterial adhesion indicated the applicability of raffinose in oral health. These effects of raffinose appear to be due to its ability to modulate GTF activity in S. mutans. Hence, raffinose may be considered an antibiofilm agent for use as a substance for oral supplies and dental materials to prevent dental caries. IMPORTANCE Dental caries is the most prevalent infectious disease and is expensive to manage. Dental biofilms can be eliminated via mechanical treatment or inhibited using antibiotics. However, bacteria that are not entirely removed or are resistant to antibiotics can still form biofilms. In this study, we found that raffinose inhibited biofilm formation by S. mutans, a causative agent of dental caries, possibly through binding to GtfC. Our findings support the notion that biofilm inhibition by raffinose can be exerted by interference with GTF function, compensating for the shortcomings of existing commercialized antibiofilm methods. Furthermore, raffinose is an ingredient derived from natural products and can be safely utilized in humans; it has no smell and tastes sweet. Therefore, raffinose, which can control S. mutans biofilm formation, has been suggested as a substance for oral supplies and dental materials to prevent dental caries.

E-Cigarette Aerosol Exposure Favors the Growth and Colonization of Oral Streptococcus mutans Compared to Commensal Streptococci

E-cigarettes (e-cigs) have drastically increased in popularity during the last decade, especially among teenagers. While recent studies have started to explore the effect of e-cigs in the oral cavity, little is known about their effects on the oral microbiota and how they could affect oral health and potentially lead to disease, including periodontitis and head and neck cancers. To explore the impact of e-cigs on oral bacteria, we selected members of the genus Streptococcus, which are abundant in the oral cavity. We exposed the commensals Streptococcus sanguinis and Streptococcus gordonii and the opportunistic pathogen Streptococcus mutans, best known for causing dental caries, to e-liquids and e-cig aerosols with and without nicotine and with and without menthol flavoring and measured changes in growth patterns and biofilm formation. Our results demonstrate that e-cig aerosols hindered the growth of S. sanguinis and S. gordonii, while they did not affect the growth of S. mutans. We also show that e-cig aerosols significantly increased biofilm formation by S. mutans but did not affect the biofilm formation of the two commensals. We found that S. mutans exhibits higher hydrophobicity and coaggregation abilities along with higher attachment to OKF6 cells than S. sanguinis and S. gordonii. Therefore, our data suggest that e-cig aerosols have the potential to dysregulate oral bacterial homeostasis by suppressing the growth of commensals while enhancing the biofilm formation of the opportunistic pathogen S. mutans. This study highlights the importance of understanding the consequences of e-cig aerosol exposure on selected commensals and pathogenic species. Future studies modeling more complex communities will provide more insight into how e-cig aerosols and vaping affect the oral microbiota. IMPORTANCE Our study shows that e-cigarette aerosol exposure of selected bacteria known to be residents of the oral cavity hinders the growth of two streptococcal commensals while enhancing biofilm formation, hydrophobicity, and attachment for the pathogen S. mutans. These results indicate that e-cigarette vaping could open a niche for opportunistic bacteria such as S. mutans to colonize the oral cavity and affect oral health.

Pulmonary actinomycosis and marijuana vaping

A 33-year-old man without significant medical history presented to the emergency department with a 6-month history of fatigue and 30 pounds of unintentional weight loss, with a recent cough and fever over the past week. He recalled two similar illnesses during college that did not require medical care. He denied tobacco use but reported inhaling marijuana 1-2 times daily over the past year with a vaping device. Physical exam was notable for a temperature of 100.0°F and an elevated blood pressure at 161/77 mm Hg. He was diaphoretic with clear breath sounds bilaterally. Chest imaging revealed diffuse ground glass opacities with subpleural sparing and mildly enlarged hilar lymph nodes. Bronchoscopy with transbronchial lung biopsies and needle aspirate of lymph nodes revealed organising pneumonia, and subsequent cultures grew Actinomyces odontolyticus He was treated with amoxicillin and corticosteroids with subsequent resolution on repeat chest imaging.