Bisphenol A in Saliva and Urine Related to Placement of Dental Composites
Condition: Dental Polymer Based Filling Material
Study type: Observational

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.
    

Intervention name(s): Restoration of dental caries with dental composite
Intervention type(s): Device
Observational model: Cohort
Time perspective: Prospective
Sampling method: Non-Probability Sample
Study population: 
        Patients scheduled for regular dental examination at the public dental clinic (Bergen
        Downtown District) and the Dental Clinic of the Student Welfare Organization in Bergen, who
        are in need for treatment with dental polymer-based filling materials, are suitable for
        study (inclusion / exclusion criteria) and have given their written informed consent.
      
Biospecimen description: 
      Saliva Urine