The Influence of Vaping on Dentinal Hypersensitivity

The use of electronic cigarettes 
(e-cigarettes) is on the rise in the United States, particularly among adolescents and young adults. Dentinal hypersensitivity, characterized by acute discomfort upon exposure to various stimuli, poses a significant oral health concern. Although commonly linked to factors, such as enamel erosion and gingival recession, the impact of vaping on dental hypersensitivity remains underexplored.

The popularity of vaping has surged in recent years and a concerning number of both teenagers and adults are lured into vaping under the misconception that it is a harmless habit as it is odorless and offers enticing flavors. Although vaping may appear less harmful than smoking cigarettes or using chewing tobacco, it can still adversely affect oral health, potentially contributing to dental hypersensitivity.

Negative Health Effects

Vaping can lead to xerostomia due to reduced saliva production, increasing the risk of dental caries, periodontal diseases, and oral malodor. The chemicals in e-cigarette vapor can irritate the gingiva causing inflammation and making them more vulnerable to infection and recession. Vaping alters the oral bacteria balance, contributing to caries and periodontal diseases.

Research hints at a heightened risk of oral cancer from vaping due to cell damage. Vaping liquids’ high sugar levels promote tooth decay as well as decrease saliva. Some users experience oral irritation, ulcers, soreness, or burning sensations from e-cigarette chemicals and flavorings.¹

Nicotine in vaping products can impede blood flow and may delay oral wound healing. It is a vasoconstrictor, which reduces blood flow to the oral tissues, potentially weakening the gingival tissue and leading to receding gingival lines.¹ This recession exposes the roots of the teeth, making them more susceptible to sensitivity. Moreover, the flavoring agents and chemicals in vape juices may contribute to tooth sensitivity. Some of these substances are acidic, leading to enamel erosion over time. Enamel erosion exposes the dentin, the sensitive layer beneath the enamel, resulting in heightened sensitivity to hot, cold, sweet, or acidic foods and drinks.

Vaping has also been linked to xerostomia, which reduces saliva production. Saliva is crucial for neutralizing acids in the mouth, washing away food particles, and demineralizing tooth enamel. A decrease in saliva not only increases the risk of tooth decay but also contributes to tooth sensitivity.¹ While research on the specific link between vaping and dental hypersensitivity is ongoing, the habit’s impact on oral health warrants consideration and further investigation.

Composition of E-Cigarettes

The prevalence of e-cigarette usage is notably higher in the young people, with approximately 20% of adolescents and 8% of adults ages 18 to 24 currently using e-cigarettes in the US. This trend is even more pronounced among adolescents ages 10 to 14.²

Vaping has become a multibillion-dollar industry, attracting not only current and former smokers but also young individuals who have never smoked. E-cigarettes entered the market without undergoing extensive preclinical toxicology testing or long-term safety trials typically required for conventional therapeutics or medical devices. Consequently, the safety of e-cigarettes remains a controversial topic, with many reported ill effects similar to those associated with regular cigarettes.³

E-cigarettes mimic the act of smoking without burning tobacco. Instead, these battery-powered devices function by heating liquid, turning it into an aerosol that is then inhaled into the lungs. The liquid utilized in an e-cigarette is termed e-liquid, also known as e-juice or vape juice. E-liquids can encompass nicotine, along with ingredients such as propylene glycol, vegetable glycerin or glycerol, various chemicals (including those for flavoring), and, in some instances, water.¹ The contents of e-liquid products may lack comprehensive or accurate labeling, and the products may not be packaged in child-resistant, secure containers.

The actual mechanism of heating the liquids so they form a viscous aerosol inhaled by the smoker poses potential problems. Some of the aerosol is absorbed into the bloodstream, some remains adherent to structures in the oral cavity, and the rest is expelled into the atmosphere.⁴

The device consists of four components: a mouthpiece, a tank or reservoir to hold the liquid, a heating element, and a lithium battery (Figure 1). Vaping devices come in various forms, including open (refillable) and closed (nonrefillable) systems, showcasing a diversity of shapes, sizes, and colors. The quantity of nicotine and other chemicals delivered by these devices significantly varies based on factors such as the liquid composition, user behavior, and device characteristics.

The type of vaping device, battery power, device settings, and the combination of internal components are influential factors.⁵ There is no assurance that an e-liquid labeled as “non-nicotine” genuinely lacks nicotine. Additionally, discerning the presence of other chemicals in e-liquid may prove challenging.

Epidemiology and Marketing

Currently, more than 10,000 e-liquid formulations are commercially available. These formulations typically consist of three components: a base, nicotine, and flavors. Each of these components has the potential to adversely impact oral health.⁵ The base is composed of propylene glycol and glycerin in purified water, with a common volume fraction ratio being 20% propylene glycol to 80% glycerin, although variations exist.

Propylene glycol, a colorless liquid with a faintly sweet taste, undergoes breakdown into acetic acid, lactic acid, and propionaldehyde when heated into an aerosol. These breakdown products have the capacity to demineralize enamel. Additionally, they exhibit hygroscopic properties, binding water in saliva and potentially leading to xerostomia.⁶

Oral Health Risks

Glycerin, a colorless, odorless, and sweet-tasting liquid, is 60% as sweet as sucrose but is not metabolized by cariogenic bacteria.⁸ However, when combined with certain flavorings, it results in a fourfold increase in microbial adhesion and doubles the formation of biofilm. The viscous nature of the heated e-liquid aerosols facilitates the attachment of Streptococcus mutans to enamel, leading to demineralization and the potential for rampant caries.⁹

The nicotine content in e-liquids exhibits considerable variation, typically ranging from 0.3% to 1.8%, generally lower than is found in conventional cigarettes.⁶ Despite this, some instances may result in nicotine exposures surpassing those of traditional cigarettes. A standard vaping session, comprising approximately 10 puffs, is commensurate to an average of 150 puffs per day for a typical user. A single electronic cartridge, yielding 200 to 400 puffs, might deliver a nicotine dose equivalent to smoking two to three packs of regular cigarettes.⁷ Notably, declared nicotine concentrations in e-liquids may deviate by up to 50%, emphasizing that actual doses are contingent on both concentration and individual vaping habits.⁶

E-liquids boast a diverse array of flavors, ranging from candy, fruits, bakery items, and beverages, to menthol and tobacco. These flavors encompass saccharides, esters, acids, and aldehydes. Sucrose or sucralose imparts the sweet taste, while ethyl maltol contributes to the fragrance.

In vitro studies indicate that certain flavors significantly enhance biofilm formation and enamel demineralization compared to a base/​nicotine control when used in vaping devices.⁷ This addition of sweet flavors is believed to enhance the appeal of e-liquids, particularly among young individuals.

While e-cigarettes are marketed as aids for smoking cessation, evidence contradicts their efficacy in this regard. Studies indicate that the odds of successful smoking cessation are 28% lower in e-cigarette users compared to nonusers.⁹ Reports suggest an 80% failure rate among those attempting to quit smoking using vaping. Rather than serving as effective cessation tools for adults, e-cigarettes may act as initiators of smoking habits among youth.⁷

The vapors generated by vaping can potentially modify or harm epithelial cells, leading to the development of oral ulcerations or oral cancer. E-cigarette aerosols contain toxic compounds, such as heavy metals, carbonyls, flavoring chemicals, and reactive oxygen species (ROS), at concentrations that can negatively impact oral health.

Some of these harmful elements, such as diacetyl, may be present in certain e-liquids, while others, such as metals, carbonyls, and ROS, can form during the vaping process.¹⁰ Vaping devices operate at temperatures ranging from 100° to 300° C. These high temperatures can facilitate the transfer of heavy metals (nickel, cadmium, chromium, lead) from the coil into the e-liquid.

Impurities in the e-liquid and breakdown of wick material may introduce toxic elements, including arsenic and silica. Aerosolization of the e-liquid during vaping releases these substances, and higher e-cigarette power output or aging of heating element wires may increase metal emissions. Prolonged exposure to these metals raises concerns about chronic periodontitis, oral cancer, inflammation, and neurodegeneration.¹¹

Adolescent Neurological Growth and Formation

Nicotine’s impact on adolescent neurological growth and formation can be significant and detrimental. Adolescence is a crucial period for brain development, with ongoing maturation and formation of neural circuits responsible for various functions such as cognition, memory, and emotion regulation.

Nicotine exposure during adolescence can disrupt the normal development of the brain by binding to nicotinic acetylcholine receptors, affecting neurotransmitter release, and altering synaptic connections, which may lead to long-term changes in brain structure and function.¹²

Adolescent nicotine use has been linked to impaired cognitive function, including deficits in attention, learning, and memory, which can persist into adulthood and potentially impact academic performance and future success.¹³ Adolescents are particularly vulnerable to developing nicotine addiction due to ongoing brain development and heightened susceptibility to the rewarding effects of addictive substances, increasing the likelihood of dependence and addiction with potential lifelong implications for health and well-being.¹³

Nicotine exposure during adolescence has been associated with an increased risk of mood disorders, such as depression and anxiety, as the neurochemical changes induced by nicotine can disrupt the delicate balance of neurotransmitters involved in mood regulation, predisposing individuals to mental health challenges.¹³

Nicotine activates the brain’s reward pathways, leading to the release of dopamine and feelings of pleasure, which with repeated exposure can become dysregulated, contributing to addictive behaviors, and potentially leading to substance abuse disorders. Nicotine use during adolescence has been associated with an increased risk of substance use disorders, including susceptibility to other drug, as well as alterations in brain development and function that may increase vulnerability to psychiatric disorders later in life.¹³

Conclusions and Recommendations

Vaping has been effectively promoted as a safer alternative to traditional cigarettes and as a means to aid individuals in successfully overcoming smoking habits. The effectiveness of this marketing initiative is evident in the substantial rise in vaping among young people.¹³ Oral health professionals need to be cognizant of the potential issues associated with vaping.

While further research is necessary to fully understand the link between vaping and dentinal hypersensitivity, the evidence points toward a negative impact on oral health. Individuals who vape must maintain good oral hygiene practices, including regular dental check-ups, to mitigate these risks. The growing awareness of the potential oral health risks associated with vaping underscores the need for more comprehensive studies and public health initiatives to inform individuals about these risks and promote healthier lifestyle choices.

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From Dimensions of Dental Hygiene. April/May 2024; 22(3):18-21