Comparative Evaluation of Salivary Bisphenol-A Levels in Patients With Fixed Lingual, Hawley and Vacuum-formed Retainers
Condition: Orthodontic Retention
Study type: Observational [Patient Registry]

Summary: 
      The aim of this study; to measure the BPA release amount of fixed lingual retainers applied
      with Bis-GMA-containing composite , fixed lingual retainers applied with Bis-GMA-free
      composite, vacuum-formed and hawley retainers which used for retention after orthodontic
      treatment to evaluate whether they are risk factors for the patient and to compare BPA
      releases.

      Study method and data collection techniques: In this study, individuals will be selected from
      the patients who will be treated at Aydın Adnan Menderes University Faculty of Dentistry,
      Department of Orthodontics between July 2021 and July 2022, whose orthodontic treatment will
      be completed. These patients will be randomly divided into four groups according to the type
      of retention appliance to be chosen: those who are applied a fixed lingual retainer with a
      bis-GMA-containing composite, those with a fixed lingual retainer with a bis-GMA-free
      composite, those with an vacuum formed retainers, and those with a hawley retainers. After
      the debonding of the fixed attachments at the end of the treatment appointment, the retention
      appliances will be applied 1 day later so that BPA, which is released from the resin
      adhesives used to bond the attachments, does not affect the study data. Saliva samples will
      be taken from the patients before the appliance is inserted, 1 hour, 7 days and 30 days after
      the appliance is inserted.
    

Detailed description: 
      Patients who are scheduled to complete their orthodontic treatment between July 2021 and July
      2022 and will be debonded will be included in the study. Inclusion criteria for the study;
      not to have any systemic diseases, not to smoke, not to work in jobs where they will be
      exposed to chronic BPA release, such as gas station-construction site or acrylic-related
      jobs. Selected patients will be randomly divided into four groups. Randomization will be done
      through the website www.random.org. Fixed lingual retainer applied with composite containing
      Bis-GMA will be applied in the first group, fixed lingual retainer applied with composite
      without Bis-GMA in the second group, vacuum formed retainers in the third group and hawley
      retainers in the fourth group. 120 patients, including 30 individuals in each group, will be
      included in the study. The number of men and women in each group will be equal. Patients who
      have undergone debonding will be given an appointment to wear retention appliances one day
      later. Patients will be advised to brush their teeth routinely, including the appointment
      day, and not to consume any food or drink at least 2 hours before the application. In
      addition, due to the effect of many drugs on salivary secretion, if patients use drugs, they
      will be told to take them at least 8 hours before the application. Saliva samples for BPA
      release will be taken before appliance insertion, 1 hour after, 7 days and 30 days after
      insertion. Samples taken will be stored in polypropylene tubes. All samples taken will be
      stored at -80 degrees until analysis. The sample will be processed by mixing 5ml saliva with
      an equal amount of ethanol and vortexing it. It will be centrifuged at 3000 rpm for 15
      minutes. The ultimately processed sample will be injected into the instrument and analyzed by
      liquid chromatography.
    

Intervention name(s): Fixed lingual retainers applied with Bis-GMA containing composite; Fixed lingual retainers applied with Bis-GMA-free composite; Vacuum-formed retainers; Hawley retainers
Intervention type(s): Device; Device; Device; Device
Intervention description(s): Bonding materials of fixed lingual retainers applied with Bis-GMA containing composite; Bonding materials of fixed lingual retainers applied with Bis-GMA-free composite; vacuum-forming machine and vacuum formed plates; Acrylic based hawley retainers
Other intervention name(s): Reliance Orthodontic Gel Etching Agent, Illinois, USA; American Orthodontics Brace Paste MTP primer, Wisconsin, USA; Reliance Orthodontic Bond-A-Braid, Illinois, USA; Reliance Orthodontic Flow Tain Low Viscosity W/TIPS, Illinois, USA; Reliance Orthodontic Gel Etching Agent, Illinois, USA; Reliance Orthodontic Bond-A-Braid, Illinois, USA; GC Ortho Connect Flow, Tokyo, Japan; Supplies Atmos Thermoforming Material 0.40 inç, USA; Dentsply Sirona, USA; Dentaurum Orthocryl, Ispringen, Germany
Observational model: Cohort
Time perspective: Prospective
Sampling method: Non-Probability Sample
Study population: 
        Men and women patients aged between 10-18 years who have completed orthodontic treatment
      
Keywords: Orthodontic retention; Bisphenol-A; lingual retainer; Hawley retainer; Vacuum formed retainer; essix plate