Composites and Urinary Bisphenol-A Study (CUBS)

The Composites and Urinary Bisphenol-A Study (CUBS) is a clinical study of dental composite for its effects on urinary bisphenol-A levels. The study will enroll approximately 139 children recruited from study-affiliated clinical sites in New England.The primary aim of CUBS is to test the hypothesis that urinary bisphenol-A (BPA) concentrations increase after composite restoration placement. BPA is a chemical used in the synthesis of matrix monomers and has been shown to have harmful effects in toxicological studies in laboratory animals. Currently it is unknown whether dental composite restorative materials containing monomers that are derived from BPA result in chronic low-dose BPA exposure in children.

Study subjects will be new or existing patients of the clinical sites who are in need of dental restorations, meet all eligibility criteria, and provide informed consent/assent to participate. Subjects will be asked to provide two pre-treatment urine samples and three post-treatment samples. Urine collections occur next-day and 14 days after treatment, with one final urine collected approximately 6 months later (marking the end of the subject's active study participation). Data will be collected from the clinician's standard oral examination (including new and existing dental treatments), the data collector's measurements of height and weight and interviews administered to the parents/guardians to assess sociodemographic and other relevant factors (e.g., recent food/beverage consumption). Confidentiality will be maintained by assigning each subject a unique number and using only this number or aggregate data in all study reports. All study records will be securely maintained with access limited to essential study personnel only.

BPA was measured, corrected for specific gravity, in ng/mL. We corrected BPA for specific gravity (SG) using the formula: BPA * [(meanSG - 1)/(SG - 1)], where meanSG is the mean of the SG for the samples examined. Urine samples were collected twice pre-treatment and the geometric mean of BPA at each pre-treatment visit was used as the baseline BPA. Change in BPA was computed using BPA at follow-up minus BPA at baseline. Analysis of change in BPA was done using the arithmetic mean.

BPA was measured, corrected for specific gravity, in ng/mL. We corrected BPA for specific gravity (SG) using the formula: BPA * [(meanSG - 1)/(SG - 1)], where meanSG is the mean of the SG for the samples examined. Urine samples were collected twice pre-treatment and the geometric mean of BPA at each pre-treatment visit was used as the baseline BPA. Change in BPA was computed using BPA at 1 day after the first dental treatment minus BPA at baseline. The first dental treatment was scheduled as per treatment needs and the schedules of the dentist and patient. It was typically within a few weeks of baseline. Analysis of change in BPA was done using the arithmetic mean.

From Baseline to 1 day after the first dental treatment (The first dental treatment was scheduled as per treatment needs and the schedules of the dentist and patient. It was typically within a few weeks of baseline.)

BPA was measured, corrected for specific gravity, in ng/mL. We corrected BPA for specific gravity (SG) using the formula: BPA * [(meanSG - 1)/(SG - 1)], where meanSG is the mean of the SG for the samples examined. Urine samples were collected twice pre-treatment and the geometric mean of BPA at each pre-treatment visit was used as the baseline BPA. Change in BPA was computed using BPA at 14 days after the first dental treatment minus BPA at baseline. The first dental treatment was scheduled as per treatment needs and the schedules of the dentist and patient. It was typically within a few weeks of baseline. Analysis of change in BPA was done using the arithmetic mean.

From Baseline to 14 days after the first dental treatment (The first dental treatment was scheduled as per treatment needs and the schedules of the dentist and patient. It was typically within a few weeks of baseline.)

BPA was measured, corrected for specific gravity, in ng/mL. We corrected BPA for specific gravity (SG) using the formula: BPA * [(meanSG - 1)/(SG - 1)], where meanSG is the mean of the SG for the samples examined. Urine samples were collected twice pre-treatment and the geometric mean of BPA at each pre-treatment visit was used as the baseline BPA. Change in BPA was computed using BPA at 1 day after the second dental treatment minus BPA at baseline. The second dental treatment was scheduled as per treatment needs and the schedules of the dentist and patient. It was typically 3-4 weeks after the first dental treatment. Analysis of change in BPA was done using the arithmetic mean.

From Baseline to 1 day after the second dental treatment (The second dental treatment was scheduled as per treatment needs and the schedules of the dentist and patient. It was typically 3-4 weeks after the first dental treatment.)

BPA was measured, corrected for specific gravity, in ng/mL. We corrected BPA for specific gravity (SG) using the formula: BPA * [(meanSG - 1)/(SG - 1)], where meanSG is the mean of the SG for the samples examined. Urine samples were collected twice pre-treatment and the geometric mean of BPA at each pre-treatment visit was used as the baseline BPA. Change in BPA was computed using BPA at 14 days after the second dental treatment minus BPA at baseline. The second dental treatment was scheduled as per treatment needs and the schedules of the dentist and patient. It was typically 3-4 weeks after the first dental treatment. Analysis of change in BPA was done using the arithmetic mean.

From Baseline to 14 days after the second dental treatment (The second dental treatment was scheduled as per treatment needs and the schedules of the dentist and patient. It was typically 3-4 weeks after the first dental treatment.)

Inclusion Criteria: Aged 3-16 (<17) years at enrollment. 2+ posterior teeth with caries requiring restorations treatable by composite. Toilet-trained (not using diapers, pull-ups, or training pants during day or night). Exclusion Criteria: Medical conditions that would render the subject physically unable to provide urine samples. Guardian is not proficient in spoken English or Spanish language Child is aged 8.0 years or older and not proficient in spoken English or Spanish language Living >35 miles outside of the dental clinic or the NERI office (Watertown MA)