Gene E Watson1, Katie Evans2, Sally W Thurston2, Edwin van Wijngaarden3, Julie M W Wallace4, Emeir M McSorley4, Maxine P Bonham4, Maria S Mulhern4, Alison J McAfee4, Philip W Davidson5, Conrad F Shamlaye6, J J Strain4, Tanzy Love2, Grazyna Zareba7, Gary J Myers8. 1. Eastman Institute for Oral Health, and Department of Pharmacology and Physiology, University of Rochester, 601 Elmwood Avenue, Box 705, Rochester, NY 14642, USA; Department of Environmental Medicine, University of Rochester, 601 Elmwood Avenue, Box EHSC, Rochester, NY 14642, USA. Electronic address: gene_watson@urmc.rochester.edu. 2. Department of Biostatistics and Computational Biology, University of Rochester, 601 Elmwood Avenue, Box 630, Rochester, NY 14642, USA. 3. Department of Community and Preventive Medicine, University of Rochester, 265 Crittenden Blvd., CU 420644, Rochester, NY 14642, USA. 4. Northern Ireland Centre for Food and Health (NICHE), University of Ulster, Cromore Road, Coleraine BT52 1SA, Northern Ireland. 5. Department of Environmental Medicine, University of Rochester, 601 Elmwood Avenue, Box EHSC, Rochester, NY 14642, USA; Department of Pediatrics, University of Rochester, 265 Crittenden Blvd., CU 420606, Rochester, NY 14642, USA. 6. Republic of Seychelles Ministry of Health and Social Services, Victoria, Mahé, Seychelles. 7. Department of Environmental Medicine, University of Rochester, 601 Elmwood Avenue, Box EHSC, Rochester, NY 14642, USA. 8. Department of Environmental Medicine, University of Rochester, 601 Elmwood Avenue, Box EHSC, Rochester, NY 14642, USA; Department of Pediatrics, University of Rochester, 265 Crittenden Blvd., CU 420606, Rochester, NY 14642, USA; Department of Neurology, University of Rochester, 601 Elmwood Avenue, Box 631, Rochester, NY 14642, USA.
Abstract
BACKGROUND: Dental amalgam is approximately 50% metallic mercury and releases mercury vapor into the oral cavity, where it is inhaled and absorbed. Maternal amalgams expose the developing fetus to mercury vapor. Mercury vapor can be toxic, but uncertainty remains whether prenatal amalgam exposure is associated with neurodevelopmental consequences in offspring. OBJECTIVE: To determine if prenatal mercury vapor exposure from maternal dental amalgam is associated with adverse effects to cognition and development in children. METHODS: We prospectively determined dental amalgam status in a cohort of 300 pregnant women recruited in 2001 in the Republic of Seychelles to study the risks and benefits of fish consumption. The primary exposure measure was maternal amalgam surfaces present during gestation. Maternal occlusal points were a secondary measure. Outcomes were the child's mental (MDI) and psychomotor (PDI) developmental indices of the Bayley Scales of Infant Development-II (BSID-II) administered at 9 and 30 months. Complete exposure, outcome, and covariate data were available on a subset of 242 mother-child pairs. RESULTS: The number of amalgam surfaces was not significantly (p>0.05) associated with either PDI or MDI scores. Similarly, secondary analysis with occlusal points showed no effect on the PDI or MDI scores for boys and girls combined. However, secondary analysis of the 9-month MDI was suggestive of an adverse association present only in girls. CONCLUSION: We found no evidence of an association between our primary exposure metric, amalgam surfaces, and neurodevelopmental endpoints. Secondary analyses using occlusal points supported these findings, but suggested the possibility of an adverse association with the MDI for girls at 9 months. Given the continued widespread use of dental amalgam, we believe additional prospective studies to clarify this issue are a priority.
BACKGROUND: Dental amalgam is approximately 50% metallic mercury and releases mercury vapor into the oral cavity, where it is inhaled and absorbed. Maternal amalgams expose the developing fetus to mercury vapor. Mercury vapor can be toxic, but uncertainty remains whether prenatal amalgam exposure is associated with neurodevelopmental consequences in offspring. OBJECTIVE: To determine if prenatal mercury vapor exposure from maternal dental amalgam is associated with adverse effects to cognition and development in children. METHODS: We prospectively determined dental amalgam status in a cohort of 300 pregnant women recruited in 2001 in the Republic of Seychelles to study the risks and benefits of fish consumption. The primary exposure measure was maternal amalgam surfaces present during gestation. Maternal occlusal points were a secondary measure. Outcomes were the child's mental (MDI) and psychomotor (PDI) developmental indices of the Bayley Scales of Infant Development-II (BSID-II) administered at 9 and 30 months. Complete exposure, outcome, and covariate data were available on a subset of 242 mother-child pairs. RESULTS: The number of amalgam surfaces was not significantly (p>0.05) associated with either PDI or MDI scores. Similarly, secondary analysis with occlusal points showed no effect on the PDI or MDI scores for boys and girls combined. However, secondary analysis of the 9-month MDI was suggestive of an adverse association present only in girls. CONCLUSION: We found no evidence of an association between our primary exposure metric, amalgam surfaces, and neurodevelopmental endpoints. Secondary analyses using occlusal points supported these findings, but suggested the possibility of an adverse association with the MDI for girls at 9 months. Given the continued widespread use of dental amalgam, we believe additional prospective studies to clarify this issue are a priority.
Authors: Sonia K Makhija; Valeria V Gordan; Gregg H Gilbert; Mark S Litaker; D Brad Rindal; Daniel J Pihlstrom; Vibeke Qvist Journal: J Am Dent Assoc Date: 2011-06 Impact factor: 3.634
Authors: Gene E Watson; Edwin van Wijngaarden; Tanzy M T Love; Emeir M McSorley; Maxine P Bonham; Maria S Mulhern; Alison J Yeates; Philip W Davidson; Conrad F Shamlaye; J J Strain; Sally W Thurston; Donald Harrington; Grazyna Zareba; Julie M W Wallace; Gary J Myers Journal: Neurotoxicol Teratol Date: 2013-07-13 Impact factor: 3.763
Authors: Edwin van Wijngaarden; Philip W Davidson; Tristram H Smith; Katie Evans; Kelley Yost; Tanzy Love; Sally W Thurston; Gene E Watson; Grazyna Zareba; Christine M Burns; Conrad F Shamlaye; Gary J Myers Journal: Epidemiology Date: 2013-09 Impact factor: 4.822
Authors: Hesam Movassagh; Yuliya Halchenko; Vanitha Sampath; Unni C Nygaard; Brian Jackson; David Robbins; Zhigang Li; Kari C Nadeau; Margaret R Karagas Journal: Environ Res Date: 2021-06-12 Impact factor: 8.431
Authors: Jean Golding; Colin D Steer; Steven Gregory; Tony Lowery; Joseph R Hibbeln; Caroline M Taylor Journal: Community Dent Oral Epidemiol Date: 2015-12-21 Impact factor: 3.383