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Bisphenol A in Saliva and Urine Related to Placement of Dental Composites

Concentration of Bisphenol A in Saliva and Urine Before and After Treatment With Polymer-based Dental Filling Materials

Status
Completed
Phases
Unknown
Study type
Observational
Source
ClinicalTrials.gov
Registry ID
NCT02575118
Enrollment
20
Registered
2015-10-14
Start date
2015-10-31
Completion date
2018-01-31
Last updated
2023-01-18

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Dental Polymer Based Filling Material

Brief summary

It has been reported that therapy with polymer-based dental filling materials was associated with higher concentrations of bisphenol A in saliva and urine directly after the treatment. The objective of the present project is to gain knowledge about the concentration of bisphenol A in saliva and urine before and after treatment with polymer-based dental filling materials, using sensitive analytical methods.

Detailed description

Bisphenol A (BPA) is a xenoestrogen which has been shown to cause abnormalities in sexual development and may lead to reproductive damage in animals. In epidemiological studies BPA has been associated with various health effects. The majority of dental plastic filling materials contain polymers synthesized from BPA. Whether BPA is released in vivo from polymer-based fillings and - if so, in what doses - is not sufficiently examined. Patients scheduled for regular dental examination at the public dental clinic, Bergen Downtown District, who needs therapy with dental polymer-based filling materials and is suitable for study (inclusion / exclusion criteria) will be informed about the project. If the patient wants to participate in the study, he/she will be given written information about the study and a consent form. It is emphasized that participation in the study is voluntary and the patient will have the opportunity to read the information at home, before the next appointment at the clinic. The clinical treatment of the carious lesion(s) will be performed according to standardized procedures and materials used at the clinic. After curing, the filling will be polished according to the standard procedures. The curing lamp will be controlled and documented weekly during the project period. All treatment sessions will be scheduled in the morning before 9 am. Questions regarding food intake and dental hygiene habits will be included in questionnaires answered during the study. Samples of saliva and urine will be collected immediately before filling placement and 1 hour, 24 hours and 1 week after treatment. A saliva sample will also be collected immediately after treatment. No food or drink intake is allowed after midnight before sample collection. Only tapped water is permitted. The sampling procedure will be controlled in advance, so that the risk of contamination of samples is minimized. After collection samples will be refrigerated and stored frozen at -80 °C until analysis. Bisphenol A in saliva and urine will be determined by liquid chromatography and mass spectrometry (LC-MS). The detection limit of the method is estimated at 0.1 ng BPA/ml. The study is approved by the Regional Committee for Medical and Health Research (reference number 2014/1529). Patients who participate in the project will have to collect saliva samples five times and urine samples four times, which involves extra visits to the clinic. The biomedical outcomes (concentration of bisphenol A in saliva and urine) will be assessed in a pre-defined group of individuals. The participants may be enrolled in the study if they fulfil the criteria (including need of a dental filling). The participants do not receive the intervention (placement of a dental filling) because they are enrolled in the study. Subjects in the study will receive the therapeutic intervention, but the investigator does not assign the intervention to the subjects of the study. Thus, the study may be described as an observational study.

Interventions

Sponsors

Hordaland County
CollaboratorOTHER_GOV
NORCE Norwegian Research Centre AS
Lead SponsorOTHER

Study design

Observational model
COHORT
Time perspective
PROSPECTIVE

Eligibility

Sex/Gender
ALL
Age
16 Years to 40 Years
Healthy volunteers
No

Inclusion criteria

* Need for filling therapy that involves at least two surfaces with a polymer-based filling material * Healthy patient without any chronic diseases * Age 16 - 40 years * Informed consent given

Exclusion criteria

* Drug abuse * Smoking * Use of snuff * Use of dental splint * Work at a dental clinic

Design outcomes

Primary

MeasureTime frameDescription
Concentration of Bisphenol A in Saliva1 weekEstimated bisphenol A (BPA) concentration (ng ml-1) in saliva
Concentration of Bisphenol A in Urine1 weekEstimated bisphenol A (BPA) concentration (ng ml-1) in urine

Countries

Norway

Participant flow

Participants by arm

ArmCount
Treatment Group
Patients in need of at least one dental restoration, involving two or more tooth surfaces, with a polymer-based restorative material were informed about the study by their dental hygienist or dentist at their regular dental examination at two public dental clinics in Bergen, Norway.
20
Total20

Baseline characteristics

CharacteristicTreatment Group
Age, Continuous23.4 years
STANDARD_DEVIATION 5.7
Education13.8 years
STANDARD_DEVIATION 1.8
Job handling receipts5 Number of Participants Handling Receipts
Race and Ethnicity Not Collected— Participants
Region of Enrollment
Norway
20 participants
Sex: Female, Male
Female
13 Participants
Sex: Female, Male
Male
7 Participants

Adverse events

Event typeEG000
affected / at risk
deaths
Total, all-cause mortality
0 / 20
other
Total, other adverse events
0 / 20
serious
Total, serious adverse events
0 / 20

Outcome results

Primary

Concentration of Bisphenol A in Saliva

Estimated bisphenol A (BPA) concentration (ng ml-1) in saliva

Time frame: 1 week

Population: n=19 at 1 week follow up (since mixed effects models were used all available data, also data for participants with missing observations at some time points, were included in the model \[see: Rabe-Hesketh and Skrondal. Multilevel and Longitudinal Modeling Using Stata, Volume I, Third Edition. 2012, page 279\])

ArmMeasureValue (MEAN)
Treatment GroupConcentration of Bisphenol A in Saliva0.25 ng/ml
Comparison: In one saliva sample collected before treatment, the BPA concentration was more than 100 times higher (11.6 ng/ml) than the mean value and more than 100 SD from the mean of the remaining 19 samples. This saliva sample was excluded from the statistical analysis because it was probably contaminated. One participant had breakfast before the sample time point 1 wk after treatment, and thus the samples collected from this participant at this time point were not included in the statistical analysis.p-value: <0.05linear mixed-effects regression models
Primary

Concentration of Bisphenol A in Urine

Estimated bisphenol A (BPA) concentration (ng ml-1) in urine

Time frame: 1 week

Population: n=19 at 1 week follow up (since mixed effects models were used all available data, also data for participants with missing observations at some time points, were included in the model \[see: Rabe-Hesketh and Skrondal. Multilevel and Longitudinal Modeling Using Stata, Volume I, Third Edition. 2012, page 279\])

ArmMeasureValue (MEAN)
Treatment GroupConcentration of Bisphenol A in Urine1.99 ng/ml
Comparison: One participant had breakfast before the sample time point 1 wk after treatment, and thus the samples collected from this participant at this time point were not included in the statistical analysis.p-value: <0.05linear mixed-effects regression models

Source: ClinicalTrials.gov · Data processed: Feb 4, 2026