Smartphone Addiction as a Behavioral Risk Factor for Xerostomia: Associations with Salivary Inflammatory Biomarkers, Sleep Quality, and Hydration in Young Adults

Background: Excessive habitual reliance on smartphones has been linked to sleep disruptions and lifestyle changes that could impact an individual's oral health.However, the association of salivary flow rate with xerostomia and salivary inflammation markers is not well known.Objective: To evaluate the correlation between compulsive smartphone dependency and salivary inflammatory biomarkers and to investigate the direct or indirect mediating effects of sleep quality and hydration status in smartphone-related xerostomia in young adults.Materials and methods: A cross-sectional empirical assessment was executed employing 180 young adults ranging from 18 to 30 years.Smartphone dependency levels were determined employing the Smartphone Addiction Scale-Short Version (SAS-SV), while the magnitude of xerostomia was appraised with the aid of the xerostomia inventory (XI).The quality of sleep was assessed using the Pittsburgh Sleep Quality Index (PSQI), and hydration status was assessed based on daily water intake.Salivary concentrations of inflammatory biomarkers entailing interleukin-6 (IL-6), tumor necrosis factor-alpha (TNF-α), and C-reactive protein (CRP) were estimated from unstimulated saliva samples.Correlation analysis, multiple linear regression modeling, and mediation analysis were systematically administered.Results: Smartphone addiction scores were positively correlated with xerostomia severity (r = 0.41, p < 0.001), sleep disturbance (r = 0.38, p < 0.001), and salivary IL-6 levels (r = 0.36, p < 0.001).Participants with high addiction scores displayed a pronounced higher level of IL-6 (3.02 ± 0.91 pg/mL) vis-à-vis those with low addiction (1.72 ± 0.63 pg/mL; p < 0.001).Multiple regression analysis identified smartphone addiction (β = 0.29, p < 0.001), sleep quality (β = 0.24, p = 0.002), and hydration status (β = -0.19,p = 0.006) as significant antecedent variables of xerostomia.Mediation analysis elucidated that sleep efficiency and hydration exerted a partial mediating effect on the association between smartphone addiction and xerostomia.Conclusion: A statistically robust association emerged between problematic smartphone usage and the occurrence of xerostomia and salivary inflammation, with sleep quality and hydration partially mediating this relationship, indicating its potential role as a modifiable risk factor for oral dryness.Clinical significance: Smartphone addiction may represent a novel behavioral risk factor for xerostomia and oral inflammatory changes.Screening for problematic smartphone use, along with counseling on sleep quality and adequate hydration, may help clinicians identify and manage individuals at risk.