Pilot study of contact sensitization to rubber allergens and bisphenol A amongst dental students.

OBJECTIVES: The aim of this study has been to evaluate the rate of contact sensitization to some rubber allergens and to bisphenol A (BPA) amongst students of dental medicine and dental patients. MATERIAL AND METHODS: A total of 50 participants were included in the study: 40 students of dental medicine exposed to the studied rubber allergens and BPA-based dental materials during the course of their education; 10 dental patients without occupational exposure to the latter substances served as a control group. All of them were patch-tested with the studied rubber allergens and bisphenol A. RESULTS: Highest was the sensitizing action of carba mix, followed by benzoyl peroxide and mercapto mix. The sensitization rate for carba mix was significantly higher for dental students as well as for the whole studied population, if compared to the one for thiuram mix (Chi2 = 12.9, p < 0.001; Chi2 = 13.9, p < 0.001), bisphenol A (Chi2 = 8.9, p < 0.001; Chi2 = 11.9, p < 0.001), toluenesulfonamide formaldehyde resin (Chi2 = 10.7, p < 0.001; Chi2 = 13.9, p < 0.001) and benzoyl peroxide (Chi2 = 4.7, p = 0.03; Chi2 = 5.8, p = 0.016), and for dental patients, if compared to the one for mercapto mix (Chi2 = 7.07, p = 0.008). Concomitant positive skin patch-test reactions to carba mix and to benzoyl peroxide, and to all the studied allergens were established. CONCLUSIONS: Carba mix could be outlined as a sensitizer of paramount importance for dental students as well as for dental patients. Benzoyl peroxide was the second ranked sensitizer for dental students. Positive skin patch-test reactions to bisphenol A and toluenesulfonamide formaldehyde resin were established only among the group of dental students. Int J Occup Med Environ Health 2017;30(3):397-405.

Concomitant contact allergy to formaldehyde and methacrylic monomers in students of dental medicine and dental patients.

OBJECTIVES: A multitude of acrylic monomers is used in dentistry. Formaldehyde is a ubiquitous chemical agent, which is an ingredient of some dental materials and may be released from methacrylate-based composites. The purpose of the study is to evaluate the incidence and the risk of cross-sensitization to some methacrylic monomers (methylmethacrylate - MMA, triethyleneglycol dimethacrylate - TEGDMA, ethyleneglycol dimethacrylate - EGDMA, 2,2-bis-[4-(2-hydroxy-3-methacrylo-xypropoxy)phenyl]-propane - Bis-GMA, 2-hydroxy-ethyl methacrylate 2-HEMA, and tetrahydrofurfuryl methacrylate) and formaldehyde in students of dentistry, dental professionals and dental patients. MATERIAL AND METHODS: A total of 139 participants were included in the study, i.e., occupationally exposed dental professionals, students of the 3rd, 4th and 6th year of dental medicine, and occupationally unexposed dental patients. They were patch-tested with methacrylic monomers and formaldehyde. The results were subjected to statistical analysis (p < 0.05). RESULTS: From the allergic to formaldehyde students of the 3rd and 4th year of dental medicine, 46.2% were also sensitized to MMA. Among the group of patients, the incidence of cross-sensitization to formaldehyde and methacrylic monomers was as follows: to TEGDMA - 20.6%, to ethyleneglycol dimethacrylate - 20.7%, to 2-HEMA - 20.7% and to tetrahydrofurfuryl methacrylate - 24.1%. Contact allergy to MMA was diagnosed among 22.7%, and to TEGDMA - among 27.1% of the students of the 3rd and 4th year of dental medicine. In the group of occupationally unexposed dental patients the prevalence of contact allergy to ethyleneglycol dimethacrylate was 20.7%, to Bis-GMA - 27.6%, to 2-HEMA - 44.9% and to tetrahydrofurfuryl methacrylate - 38.0%. CONCLUSIONS: The students of the 3rd and 4th year of dental medicine could be outlined as a group at risk of sensitization to MMA and TEGDMA and of cross-sensitization to MMA and formaldehyde. Probably, due to the ubiquitous occurrence of formaldehyde and the wide use of composite resins and bonding agents containing TEGDMA, ethyleneglycol dimethacrylate, 2-HEMA and tetrahydrofurfuryl methacrylate in dentistry, the group of dental patients could be at risk of cross-sensitization to formaldehyde and some methacrylic monomers.