HHS Public Access Author manuscript Author Manuscript
Pediatr Dent. Author manuscript; available in PMC 2016 May 03. Published in final edited form as: Pediatr Dent. 2014 ; 36(1): 68–75.
Dental Sealants and Flowable Composite Restorations and Psychosocial, Neuropsychological, and Physical Development in Children
Author Manuscript
Nancy N. Maserejian, ScD1,2, Peter Shrader, MA1, Felicia L. Trachtenberg, PhD1, Russ Hauser, MD, ScD, MPH3,4, David C. Bellinger, PhD, MSc3,5,6, and Mary Tavares, DMD, MPH2,7 Nancy N. Maserejian: [email protected]; Peter Shrader: [email protected]; Felicia L. Trachtenberg: [email protected]; Russ Hauser: [email protected]; David C. Bellinger: [email protected]; Mary Tavares: [email protected] 1Dept.
of Epidemiology, New England Research Institutes, Watertown, MA
2Dept.
of Oral Health Policy and Epidemiology, Harvard School of Dental Medicine, Boston, MA
3Harvard
School of Public Health, Boston, MA
4Vincent
Obstetrics and Gynecology, Massachusetts General Hospital and Harvard Medical School, Boston, MA
5Department 6Harvard
Author Manuscript
7The
of Neurology, Boston Children’s Hospital, Boston MA
Medical School, 25 Shattuck St., Boston, MA
Forsyth Institute, Cambridge, MA
Abstract Purpose—Dental sealant materials may release their components, including bisphenol-A (BPA), intra-orally, but long-term health effects are uncertain. The New England Children’s Amalgam Trial (NECAT) found that composite restorations were associated with psychosocial, but not neuropsychological or physical, outcomes. The previous analysis did not consider sealants and preventive resin restorations (PRRs), which were routinely placed during NECAT. This analysis examines sealant/PRR exposure in association with psychosocial and other health outcomes.
Author Manuscript
Methods—NECAT recruited 534 children aged 6–10 years and provided dental care during 5year follow-up. Annually, examiners conducted psychosocial and neuropsychological tests, and measured body mass index (BMI) and fat percentage (BF%). Associations between surface-years (SY) of sealants/PRRs and outcomes were tested using multivariable models.
Corresponding Author: Nancy Nairi Maserejian, ScD, New England Research Institutes, Inc. 9 Galen Street, Watertown, MA 02472, Direct Dial Tel: (01) 617.972.3229, [email protected]. The content of this work is solely the responsibility of the authors and does not necessarily represent the official views of the National Institute of Environmental Health Sciences, the National Institute of Dental and Craniofacial Research, or the National Institutes of Health. Trial Registration: clinicaltrials.gov Identifier: NCT00065988 Conflict of Interest and Financial Disclosures: Authors have no potential conflicts of interest and no financial disclosures.
Maserejian et al.
Page 2
Author Manuscript
Results—Cumulative exposure level to sealants and/or PRRs was not associated with psychosocial assessments (e.g. total problems: Child Behavior Checklist, 10-SY β=−0.2, SE=0.3, P=0.6) or neuropsychological tests (e.g. full-scale IQ, 10-SY β=0.1, SE=0.2, P=0.6). There were no associations for changes in BMI-for-age z-score (P=0.4), BF% (girls 10-SY β= −0.2 SE=0.3; boys 10-SY β= −0.1 SE=0.3), or menarche (10-SY hazard ratio=0.91, 95%CI 0.83–1.01, P=0.08). Conclusions—This analysis showed no significant associations between exposure level of dental sealants or PRRs and behavioral, neuropsychological, or physical development in children during 5-year follow-up. MeSH Keywords
Author Manuscript
Composite dental resin; Composite resins; Bisphenol A-Glycidyl Methacrylate; Compomers; Child behavior; Behavioral symptoms; Affective symptoms; Child Development; Neuropsychological tests; Executive Function; Body mass index; Menarche; Child; Body composition; Epidemiology; Prospective Studies
INTRODUCTION
Author Manuscript
Dental sealants on primary and permanent molar teeth are an important component of children’s oral health and caries prevention.1–3 Despite their proven benefits, recent concerns regarding chemical exposures from dental materials have resulted from laboratory findings indicating that the resins used in sealants are possible exposure sources to bisphenol-A (BPA) and other compounds that have potential adverse effects.4–7 BPA is a well-known endocrine disruptor and causes a variety of adverse health effects at low dose exposure levels in laboratory animal experiments.8 The main monomer used in many manufactured sealants today, bisphenol-A-glycidyl-dimethacrylate (bisGMA), has also been shown to cause local cytotoxicity, DNA damage, and estrogenic activity.9–13 For example, BisGMA exposure significantly reduced fertility, with reductions in sperm counts, weights of testis and preputial glands, and overall body weight in adult male mice,14 and significantly increased embryo resorption rates and ovary weights in adult female mice.15 Observational human cohort studies have identified associations between urinary BPA levels and various adverse health measures, ranging from behavior problems in children to coronary artery disease in adults.16–22 However, additional longitudinal studies are needed to help examine causal associations.
Author Manuscript
Clinical studies measuring salivary and/or urinary bisGMA, BPA and other compounds before and after placement of sealants or composite restorations have shown increased biomarker levels up to 30 hours after their placement in adults.23–27 Children have higher levels of urinary BPA than all other age groups in the U.S. and may be most sensitive to exposure effects.28 Previously, we examined the association of composite restoration placement with adverse health outcomes over five years, using data from the New England Children’s Amalgam Trial (NECAT). NECAT randomized 534 children to receive either amalgam or composite for posterior tooth restorations, collecting detailed data to allow an examination of treatment levels over time. While results showed no adverse effects for amalgam,29 children randomized to composites, especially those with greater exposure to bisGMA-based composites, had worse psychosocial health measures during follow-up.30, 31
Pediatr Dent. Author manuscript; available in PMC 2016 May 03.
Maserejian et al.
Page 3
Author Manuscript
Further examination of neuropsychological test scores and physical development measures showed no consistent associations between composites and those outcomes, indicating specificity to behavioral health effects.32, 33 In addition to restorative fillings, all children participating in NECAT received pit and fissure sealants during the 5-year trial, and, as needed, flowable composite for preventive resin restorations (PRRs) for shallow caries. Compared to composites used for restorations, sealants are designed to be highly flowable, to facilitate their infiltration onto the surfaces of dental pits and fissures. The high viscosity of sealants and flowable composites is attained by using substantially greater amounts of resin monomers that contain bisGMA.
Author Manuscript
No prior studies have examined exposure to dental sealants in association with long-term adverse health effects in children. The objective of this manuscript was to examine whether, consistent with previous findings for packable composite restorations in NECAT,30, 31 flowable composite (sealants and PRRs) treatment levels were associated with the behavioral outcome measures. We also examined associations between sealants/PRRs and neuropsychological and physical development measures during the 5-year follow-up.
METHODS Study Population
Author Manuscript
NECAT was a randomized safety clinical trial of amalgam vs. composite for posterior restorations conducted among 534 children at six community dental clinics in urban Boston and rural Maine from 1997–2005. Eligible children were aged 6–10 years at baseline, had no existing amalgam restorations; ≥2 posterior teeth with caries requiring restoration on occlusal surfaces; fluent in English, and, by parent-report, no physician-diagnosed psychological, behavioral, neurological, immunosuppressive or renal disease. Written informed consent was obtained from the parent/guardian, and signed assent was obtained for children aged eight years or older. The study was approved by the institutional review boards of New England Research Institutes (Watertown, MA, USA) and all participating sites. Additional details on the study procedures have been published.29, 34, 35 Dental Materials and Interventions
Author Manuscript
Participants received comprehensive dental care semi-annually during their 5-year participation. Standard dental care included exams, cleaning, fluoride application, sealant placement, and restorative treatment. Dental procedures and materials were standardized across study sites, following manufacturer’s indications for use. The flowable composite material used for preventive sealing of sound pits and fissures of posterior teeth, referred to as a sealant, was Ultraseal XT by Ultradent (South Jordan, Utah, USA). The flowable composite used for PRRs, which treated shallow, incipient caries that did not extend into the dentin, was Revolution by Kerr (Orange, Calif., USA). Composite restoration materials used were Z100 by 3M ESPE (St. Paul, Minn., USA) for permanent teeth, and Dyract AP compomer by Dentsply Caulk (Milford, Del., USA) for primary teeth. Sealants and PRRs were placed as needed regardless of assigned treatment group for restorations.
Pediatr Dent. Author manuscript; available in PMC 2016 May 03.
Maserejian et al.
Page 4
Health Outcome Measures
Author Manuscript Author Manuscript
One supervising psychologist (D.C.B.) trained and certified examiners to conduct psychosocial and neuropsychological tests and continuously monitored them for quality control throughout the trial. The study used two validated instruments for psychosocial assessments at baseline and follow-up: (1) Child Behavior Checklist (CBCL) parentreport,36 and (2) Behavior Assessment for Children Self-Report (BASC-SR).37 Both are widely used in screening children and adolescents for psychosocial problems,38 yielding global T-scores (mean 50, SD=10) and core syndrome scores. Based on our previous findings, the primary outcomes of interest were BASC-SR scores on the four global scales (Total emotional symptoms index, Clinical maladjustment, School maladjustment, Personal adjustment) measured at the end of 5-year follow-up. We did not analyze change since baseline for BASC-SR because most (63 percent) of the subjects were 0.05) between sealant/PRR exposure and body mass or body fat changes. Table presents multivariableadjusted mean changes over follow-up. All models were adjusted for age and either baseline BMI z-score (for BMI models) or height and baseline body fat percentage (for body fat models). For boys, models additionally were adjusted for household income ($40k) and race/ethnicity. For girls, models were additionally adjusted for daily servings of fruits and vegetables.
Author Manuscript Author Manuscript Pediatr Dent. Author manuscript; available in PMC 2016 May 03.
Pediatr Dent. Author manuscript; available in PMC 2016 May 03. Published in final edited form as: Pediatr Dent. 2014 ; 36(1): 68–75.
Dental Sealants and Flowable Composite Restorations and Psychosocial, Neuropsychological, and Physical Development in Children
Author Manuscript
Nancy N. Maserejian, ScD1,2, Peter Shrader, MA1, Felicia L. Trachtenberg, PhD1, Russ Hauser, MD, ScD, MPH3,4, David C. Bellinger, PhD, MSc3,5,6, and Mary Tavares, DMD, MPH2,7 Nancy N. Maserejian: [email protected]; Peter Shrader: [email protected]; Felicia L. Trachtenberg: [email protected]; Russ Hauser: [email protected]; David C. Bellinger: [email protected]; Mary Tavares: [email protected] 1Dept.
of Epidemiology, New England Research Institutes, Watertown, MA
2Dept.
of Oral Health Policy and Epidemiology, Harvard School of Dental Medicine, Boston, MA
3Harvard
School of Public Health, Boston, MA
4Vincent
Obstetrics and Gynecology, Massachusetts General Hospital and Harvard Medical School, Boston, MA
5Department 6Harvard
Author Manuscript
7The
of Neurology, Boston Children’s Hospital, Boston MA
Medical School, 25 Shattuck St., Boston, MA
Forsyth Institute, Cambridge, MA
Abstract Purpose—Dental sealant materials may release their components, including bisphenol-A (BPA), intra-orally, but long-term health effects are uncertain. The New England Children’s Amalgam Trial (NECAT) found that composite restorations were associated with psychosocial, but not neuropsychological or physical, outcomes. The previous analysis did not consider sealants and preventive resin restorations (PRRs), which were routinely placed during NECAT. This analysis examines sealant/PRR exposure in association with psychosocial and other health outcomes.
Author Manuscript
Methods—NECAT recruited 534 children aged 6–10 years and provided dental care during 5year follow-up. Annually, examiners conducted psychosocial and neuropsychological tests, and measured body mass index (BMI) and fat percentage (BF%). Associations between surface-years (SY) of sealants/PRRs and outcomes were tested using multivariable models.
Corresponding Author: Nancy Nairi Maserejian, ScD, New England Research Institutes, Inc. 9 Galen Street, Watertown, MA 02472, Direct Dial Tel: (01) 617.972.3229, [email protected]. The content of this work is solely the responsibility of the authors and does not necessarily represent the official views of the National Institute of Environmental Health Sciences, the National Institute of Dental and Craniofacial Research, or the National Institutes of Health. Trial Registration: clinicaltrials.gov Identifier: NCT00065988 Conflict of Interest and Financial Disclosures: Authors have no potential conflicts of interest and no financial disclosures.
Maserejian et al.
Page 2
Author Manuscript
Results—Cumulative exposure level to sealants and/or PRRs was not associated with psychosocial assessments (e.g. total problems: Child Behavior Checklist, 10-SY β=−0.2, SE=0.3, P=0.6) or neuropsychological tests (e.g. full-scale IQ, 10-SY β=0.1, SE=0.2, P=0.6). There were no associations for changes in BMI-for-age z-score (P=0.4), BF% (girls 10-SY β= −0.2 SE=0.3; boys 10-SY β= −0.1 SE=0.3), or menarche (10-SY hazard ratio=0.91, 95%CI 0.83–1.01, P=0.08). Conclusions—This analysis showed no significant associations between exposure level of dental sealants or PRRs and behavioral, neuropsychological, or physical development in children during 5-year follow-up. MeSH Keywords
Author Manuscript
Composite dental resin; Composite resins; Bisphenol A-Glycidyl Methacrylate; Compomers; Child behavior; Behavioral symptoms; Affective symptoms; Child Development; Neuropsychological tests; Executive Function; Body mass index; Menarche; Child; Body composition; Epidemiology; Prospective Studies
INTRODUCTION
Author Manuscript
Dental sealants on primary and permanent molar teeth are an important component of children’s oral health and caries prevention.1–3 Despite their proven benefits, recent concerns regarding chemical exposures from dental materials have resulted from laboratory findings indicating that the resins used in sealants are possible exposure sources to bisphenol-A (BPA) and other compounds that have potential adverse effects.4–7 BPA is a well-known endocrine disruptor and causes a variety of adverse health effects at low dose exposure levels in laboratory animal experiments.8 The main monomer used in many manufactured sealants today, bisphenol-A-glycidyl-dimethacrylate (bisGMA), has also been shown to cause local cytotoxicity, DNA damage, and estrogenic activity.9–13 For example, BisGMA exposure significantly reduced fertility, with reductions in sperm counts, weights of testis and preputial glands, and overall body weight in adult male mice,14 and significantly increased embryo resorption rates and ovary weights in adult female mice.15 Observational human cohort studies have identified associations between urinary BPA levels and various adverse health measures, ranging from behavior problems in children to coronary artery disease in adults.16–22 However, additional longitudinal studies are needed to help examine causal associations.
Author Manuscript
Clinical studies measuring salivary and/or urinary bisGMA, BPA and other compounds before and after placement of sealants or composite restorations have shown increased biomarker levels up to 30 hours after their placement in adults.23–27 Children have higher levels of urinary BPA than all other age groups in the U.S. and may be most sensitive to exposure effects.28 Previously, we examined the association of composite restoration placement with adverse health outcomes over five years, using data from the New England Children’s Amalgam Trial (NECAT). NECAT randomized 534 children to receive either amalgam or composite for posterior tooth restorations, collecting detailed data to allow an examination of treatment levels over time. While results showed no adverse effects for amalgam,29 children randomized to composites, especially those with greater exposure to bisGMA-based composites, had worse psychosocial health measures during follow-up.30, 31
Pediatr Dent. Author manuscript; available in PMC 2016 May 03.
Maserejian et al.
Page 3
Author Manuscript
Further examination of neuropsychological test scores and physical development measures showed no consistent associations between composites and those outcomes, indicating specificity to behavioral health effects.32, 33 In addition to restorative fillings, all children participating in NECAT received pit and fissure sealants during the 5-year trial, and, as needed, flowable composite for preventive resin restorations (PRRs) for shallow caries. Compared to composites used for restorations, sealants are designed to be highly flowable, to facilitate their infiltration onto the surfaces of dental pits and fissures. The high viscosity of sealants and flowable composites is attained by using substantially greater amounts of resin monomers that contain bisGMA.
Author Manuscript
No prior studies have examined exposure to dental sealants in association with long-term adverse health effects in children. The objective of this manuscript was to examine whether, consistent with previous findings for packable composite restorations in NECAT,30, 31 flowable composite (sealants and PRRs) treatment levels were associated with the behavioral outcome measures. We also examined associations between sealants/PRRs and neuropsychological and physical development measures during the 5-year follow-up.
METHODS Study Population
Author Manuscript
NECAT was a randomized safety clinical trial of amalgam vs. composite for posterior restorations conducted among 534 children at six community dental clinics in urban Boston and rural Maine from 1997–2005. Eligible children were aged 6–10 years at baseline, had no existing amalgam restorations; ≥2 posterior teeth with caries requiring restoration on occlusal surfaces; fluent in English, and, by parent-report, no physician-diagnosed psychological, behavioral, neurological, immunosuppressive or renal disease. Written informed consent was obtained from the parent/guardian, and signed assent was obtained for children aged eight years or older. The study was approved by the institutional review boards of New England Research Institutes (Watertown, MA, USA) and all participating sites. Additional details on the study procedures have been published.29, 34, 35 Dental Materials and Interventions
Author Manuscript
Participants received comprehensive dental care semi-annually during their 5-year participation. Standard dental care included exams, cleaning, fluoride application, sealant placement, and restorative treatment. Dental procedures and materials were standardized across study sites, following manufacturer’s indications for use. The flowable composite material used for preventive sealing of sound pits and fissures of posterior teeth, referred to as a sealant, was Ultraseal XT by Ultradent (South Jordan, Utah, USA). The flowable composite used for PRRs, which treated shallow, incipient caries that did not extend into the dentin, was Revolution by Kerr (Orange, Calif., USA). Composite restoration materials used were Z100 by 3M ESPE (St. Paul, Minn., USA) for permanent teeth, and Dyract AP compomer by Dentsply Caulk (Milford, Del., USA) for primary teeth. Sealants and PRRs were placed as needed regardless of assigned treatment group for restorations.
Pediatr Dent. Author manuscript; available in PMC 2016 May 03.
Maserejian et al.
Page 4
Health Outcome Measures
Author Manuscript Author Manuscript
One supervising psychologist (D.C.B.) trained and certified examiners to conduct psychosocial and neuropsychological tests and continuously monitored them for quality control throughout the trial. The study used two validated instruments for psychosocial assessments at baseline and follow-up: (1) Child Behavior Checklist (CBCL) parentreport,36 and (2) Behavior Assessment for Children Self-Report (BASC-SR).37 Both are widely used in screening children and adolescents for psychosocial problems,38 yielding global T-scores (mean 50, SD=10) and core syndrome scores. Based on our previous findings, the primary outcomes of interest were BASC-SR scores on the four global scales (Total emotional symptoms index, Clinical maladjustment, School maladjustment, Personal adjustment) measured at the end of 5-year follow-up. We did not analyze change since baseline for BASC-SR because most (63 percent) of the subjects were 0.05) between sealant/PRR exposure and body mass or body fat changes. Table presents multivariableadjusted mean changes over follow-up. All models were adjusted for age and either baseline BMI z-score (for BMI models) or height and baseline body fat percentage (for body fat models). For boys, models additionally were adjusted for household income ($40k) and race/ethnicity. For girls, models were additionally adjusted for daily servings of fruits and vegetables.
Author Manuscript Author Manuscript Pediatr Dent. Author manuscript; available in PMC 2016 May 03.
