title: Moisture insensitive primer: A myth or truth.
abstract: OBJECTIVE
  To compare the mean shear bond strength (SBS) of moisture insensitive primer (MIP) used for orthodontic bonding in the presence and absence of saliva.
  
  
  METHODS
  A total of 60 human noncarious maxillary premolars with sound buccal surfaces, recently extracted were collected in two groups of each 30. Maxillary premolar brackets were bonded to the teeth using light cure (Transbond XT, 3M Unitek, Monrovia, CA, USA) and MIP (Transbond MIP 3M Unitek, Monrovia, CA, USA,) in the presence and absence of saliva. Operators' saliva was used during the bonding under moist condition. After debonding, all the specimens were examined under a stereomicroscope (×40 magnification) for adhesive remnant using adhesive remnant index (ARI). The SBS tests were done using Instron universal testing machine at cross-head speed of 1 mm/min, force passing parallel to the buccal surface using custom rod and registered in Newtons later converted into Megapascals.
  
  
  RESULTS
  Light cure and MIP (Transbond MIP and Transbond XT, 3M Unitek, Monrovia, CA, USA) in the absence of saliva showed higher mean SBS than the presence of saliva. Group I (light cure and MIP) in the absence of saliva showed mean SBS of 9.65 ± 0.90 Mpa. Group II (light cure and MIP) with the presence of saliva showed mean SBS of 9.03 ± 1.14 Mpa. The difference between both the groups was statistically significant, as confirmed by paired t-test (P < 0.05). In-Group I, ARI scores showed that more than half of the adhesive was left over the tooth surface, and Group II showed that there was no or insignificant amount of adhesive left over the tooth surface. Chi-square test revealed significant difference in debonding characteristics among the test groups of ARI (P < 0.05). Failure occurred mainly in resin- bracket base and resin - adhesive interfaces (χ² = 10.04, df = 3, P = 0.031).
  
  
  CONCLUSIONS
  Moisture insensitive primer is effective in the presence/absence of moisture and has shown SBS value of more than 7.8 Mpa as stated by Reynolds, hence material is suitable for clinical use.
authors.affiliation: Department of Orthodontics and Dentofacial Orthopedics, Peoples College of Dental Sciences and RC, Bhopal, Madhya Pradesh, India.
authors.forename: Chandresh
authors.initials: C
authors.lastname: Shukla
authors.affiliation: Corps Dental Unit, Department of Orthodontics and Dentofacial Orthopedics, Bhopal, Madhya Pradesh, India.
authors.forename: Rajkumar
authors.initials: R
authors.lastname: Maurya
authors.affiliation: Department of Orthodontics and Dentofacial Orthopedics, Peoples College of Dental Sciences and RC, Bhopal, Madhya Pradesh, India.
authors.forename: Upendra
authors.initials: U
authors.lastname: Jain
authors.affiliation: Department of Orthodontics, IDS, Bareilly, Uttar Pradesh, India.
authors.forename: Ankur
authors.initials: A
authors.lastname: Gupta
authors.affiliation: Department of Periodontics, IDS, Bareilly, Uttar Pradesh, India.
authors.forename: Jayshree
authors.initials: J
authors.lastname: Garg
keywords: Adhesive remnant index; moisture insensitive primer; shear bond strength