Transepithelial electrical resistance and cellular viability responses to teething gels: an in vitro study

OBJECTIVE: This study aimed to evaluate the in vitro effects of commercially available teething gels with different formulations on epithelial barrier integrity and cellular viability. MATERIALS AND METHODS: Six commercially available teething gels were tested at concentrations of 0.1%, 20%, 50%, and 80%. Cellular viability was assessed using the MTT assay in human gingival mesenchymal stem cells after 72 h of exposure. Epithelial barrier integrity was evaluated by measuring transepithelial electrical resistance (TEER) in HaCaT keratinocyte cells cultured on transwell inserts at 24, 48, and 72 h. Statistical analyses were performed using IBM SPSS Statistics 27, applying mixed-design and two-way ANOVA with appropriate post hoc tests, with significance set at p < 0.05. RESULTS: TEER values differed significantly according to gel type, concentration, and exposure time (p < 0.05). At 0.1%, significant intergroup differences were observed at 24 h (p = 0.001) and 72 h (p = 0.017), with Dentinox showing significantly lower TEER values than Gengigel, Aftamed, Buccotherm, and Jack N'Jill. At 20%, 50%, and 80% concentrations, Dentinox consistently exhibited reduced TEER levels at 24-72 h (p = 0.001), whereas Gengigel showed higher TEER values mainly at 24 h (20%) and 72 h (50%), and Buccotherm at 48 h across higher concentrations. MTT analysis revealed significant gel- and concentration-dependent differences at 20%, 50%, and 80% (p = 0.001). Jack N'Jill exhibited higher cell viability at 20%, while both Jack N'Jill and Buccotherm showed higher viability at 50% and 80%. CONCLUSIONS: Teething gels exert formulation, concentration, and time-dependent effects on epithelial barrier integrity and cellular viability, emphasizing the need for careful evaluation of products intended for infant use. CLINICAL RELEVANCE: This study demonstrates that teething gels with different formulations and concentrations can differentially affect epithelial barrier integrity and cellular viability. These findings highlight the clinical importance of carefully evaluating teething gel composition and concentration, particularly for products intended for use in infants and young children.