title: Orthodontic instrument sterilization with microwave irradiation.
abstract: OBJECTIVE
  This study was designed to evaluate the efficiency of microwave sterilization of orthodontic instruments and molar bands immersed in plain distilled water with and without oral rinse, and to ascertain the minimum time of exposure required to sterilize.
  
  
  METHODS
  The orthodontic instruments (hinged and nonhinged), molar bands and mouth mirrorsused in the patient 's mouth were selected for the study. The instruments were divided into two groups - Group I with oral rinse-set A (0.01% chlorhexidine gluconate) and set B (0.025% betadine) and Group II (included sets C and D without oral rinse). The instruments of set A, B and C were microwaved at 2,450 MHz, 800 W for 5 min, whereas, set D was microwaved for 10 min at the same above mentioned specifications. The efficacy of sterilization was assessed by stab inoculation of the instruments onto trypticase soya agar plates. The plates were checked for bacterial growth following incubation at 37 °C for 24 h. For sterility control,Geobacillus stearothermophilus (MTCC 1518) was included.
  
  
  RESULTS
  No growth was observed in the plates that were inoculated with the microwaved orthodontic instruments of sets A, B and D, whereas scanty bacterial growth was observed in the plates inoculatedwith the microwaved set C instruments.
  
  
  CONCLUSIONS
  Effective sterilization was achieved when the orthodontic instruments and molar bands were immersed in distilled water without oral rinse and microwaved for 10 min as also for those that were immersed in distilled water with oral rinse and microwaved for 5 min.
authors.affiliation: Department of Orthodontics and Dentofacial Orthopedics Sree Balaji Dental College and Hospital, Bharath University, Chennai, Tamil Nadu, India.
authors.forename: Arif
authors.initials: A
authors.lastname: Yezdani
authors.affiliation: Department of Microbiology, Sree Balaji Dental College and Hospital, Bharath University, Chennai, Tamil Nadu, India.
authors.forename: Krishnan
authors.initials: K
authors.lastname: Mahalakshmi
authors.affiliation: Department of Microbiology, Sree Balaji Dental College and Hospital, Bharath University, Chennai, Tamil Nadu, India.
authors.forename: Kesavaram
authors.initials: K
authors.lastname: Padmavathy
keywords: Biological indicator; microwave sterilization; molar bands; orthodontic pliers