Contact sensitization to ingredients of dental materials and cosmetics in dental students: a pilot study.

OBJECTIVE: The aim of this study was to evaluate the rate of contact sensitization to selected cosmetic allergens, i.e. ingredients of dental materials, in students of dental medicine and dental patients. METHODS: A total of 50 participants were included in the study: 40 students of dental medicine exposed to the studied allergens during the course of practical education; and 10 randomly selected dental patients without occupational exposure to the investigated substances served as a control group. All of them were patch-tested with colophonium, myroxylon pereirae resin, paraben mix, fragrance mix I, isopropyl myristate, triclosan, polysorbate 80, compositae mix II, and hydroperoxides of limonene. RESULTS: The sensitization rates for colophonium and polysorbate 80 were the highest. For the group of dental students, we established significantly higher sensitization rate for colophonium compared to the ones for myroxylon pereirae resin and hydroperoxides of limonene (χ2 = 4.93; p = 0.026), paraben mix (χ2 = 3.6; p = 0.05), isopropyl myristate (χ2 = 6.56; p = 0.01), and triclosan (χ2 = 8.5; p < 0.001); and to polysorbate 80 compared to the ones for myroxylon pereirae resin and hydroperoxides of limonene (χ2 = 3.97; p = 0.046), isopropyl myristate (χ2 = 5.47; p = 0.02) and triclosan (χ2 = 7.34; p = 0.007). Significantly increased concomitant sensitization rate to compositae mix and to hydroperoxides of limonene was established (χ2 = 12.55; p < 0.001). Generally, the incidence of concomitant sensitization to the studied allergens in the whole studied population was high. CONCLUSIONS: Colophonium and polysorbate 80 could be outlined as sensitizers of paramount importance for both dental students and dental patients. We consider the major importance of exposure to colophonium during the course of practical education in dentistry for the onset of the sensitization. Sensitization to compositae mix was observed only among dental students. We consider the leading role of consumer exposure for the onset of the sensitization to triclosan and to hydroperoxides of limonene. Unexpected and unreported reactions of concomitant sensitization were observed.

Concomitant sensitization to glutaraldehyde and methacrylic monomers among dentists and their patients.

BACKGROUND: A multitude of methacrylic monomers is used in dentistry. Glutaraldehyde (G) is used in dental practice and consumer products as a broad-spectrum antimicrobial agent. The purpose of our study is to evaluate the frequency and the risk of concomitant sensitization to some methacrylic monomers (methyl methacrylate (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 (THFMA)) and glutaraldehyde in students of dentistry, students from the dental technician school, dental professionals and dental patients. MATERIAL AND METHODS: A total of 262 participants were included in the study: students of dentistry, students from the dental technician school, dental professionals, and dental patients as a control group. All were patch-tested with methacrylic monomers and glutaraldehyde. The results were subject to the statistical analysis (p < 0.05). RESULTS: Among the group of dental students, the highest frequency of concomitant sensitization was to TEGDMA and G (15.5%). In the group of patients the highest frequency of concomitant sensitization was to EGDMA and G (16.4%). The frequency of concomitant sensitization among dental professionals was much lower, with the highest rate to TEGDMA and G (7.7%), too. We consider the students from the dental technician school, where the exposure to glutaraldehyde is less likely, to be the group at a lesser risk of concomitant sensitization. CONCLUSIONS: Dental students and dental patients could be outlined as groups at the risk of concomitant sensitization to glutaraldehyde and methacrylic monomers. For dental professionals, we assumed an increased risk for concomitant sensitization to TEGDMA and aldehydes that are commonly used in dentistry. We consider the students from the dental technician school to be the group at a lesser risk of concomitant sensitization to glutaraldehyde and methacrylic monomers. Med Pr 2016;67(3):311-320.

Contact Sensitization to Formaldehyde in Veterinary Medicine - An Unexplored Field in Occupational Health.

BACKGROUND: Veterinary staff and students could be exposed to formaldehyde - a ubiquitous agent, common cause of contact allergy. AIM: To evaluate the incidence of contact sensitization to formaldehyde in exposures in veterinary medicine. SETTINGS AND DESIGN: A cross-sectional study was conducted during July-December 2017. MATERIALS AND METHODS: A total of 206 individuals were included, patch tested with formaldehyde 1.0%/aq - 36 veterinary medicine students, 20 veterinarians, 47 students and 28 trainees of dental medicine, 41 dental professionals, and 35 non-occupationally exposed individuals. RESULTS: The incidence of contact sensitization to formaldehyde among the whole studied population was 48.1%, highest being among the students of veterinary medicine (94.4%) and the veterinarians (85%). With very high significance, the sensitization incidence was higher in the groups of students of veterinary medicine and veterinarians, if compared to the control group (P < 0.001); (P = 0.004), dental professionals (P < 0.001); (P = 0.001), trainees of dental medicine (P < 0.001); (P = 0.005), and students of dental medicine three-fourth year of education (P < 0.001); (P = 0.001). Significantly, higher was the incidence of contact allergy in the control group if compared to those of dental professionals (P = 0.033) and dental students three-fourth year of education (P = 0.028). CONCLUSIONS: The exposure to formaldehyde during the education in veterinary medicine and practice could be an important risk factor for the onset of contact sensitization. Stricter preventive measures are needed to reduce veterinary student's and lecturer's exposures. Equipment of dissection tables with local exhaust ventilation system could reduce the concentration of formaldehyde in the gross anatomy laboratory.

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.