Effects of Fluorosis on Shear Bond Strengths of Orthodontic Brackets Bonded with Self Etching Primer

  • Assistant Professor Dr Devrim Isci, University of Ondokuz Mayis, Faculty of Dentistry, Department of Orthodontics, Samsun., Turkey
  • Associate Professor Dr Aynur Sahin Saglam, Inci-Dent Dental Hospital, Isparta., Turkey
  • PhD Student Huseyin Alkis, University of Süleyman Demirel, Faculty of Dentistry, Department of Orthodontics, Isparta., Turkey
  • Assistant Professor Dr Selma Elekdag-Turk, University of Ondokuz Mayis, Faculty of Dentistry, Department of Orthodontics, Samsun., Turkey
  • Professor Dr Tamer Turk, University of Ondokuz Mayis, Faculty of Dentistry, Department of Orthodontics, Samsun., Turkey

Objective: To compare the shear bond strength (SBS) and the bond failure site of brackets bonded to fluorosed and non-fluorosed teeth conditioned with self-etching pirmer (SEP) and phosphoric acid (PA).
Materials and Methods: The study involved 40 fluorosed and 40 non-fluorosed fresh human premolar teeth. Fluorosed teeth were classified with the Thylstrup-Fejerskov Index (TFI) as mildly fluorosed (TFI=1–3). Fluorosed and non-fluorosed teeth were randomly divided into two sub-groups: to the first sub-group 37% PA was applied for 30 seconds and to the other sub-group an SEP (Transbond Plus, 3M Unitek, Monrovia, CA) was applied as recommended by the manufacturer. Brackets were bonded with light-cure adhesive paste (Transbond XT, 3M Unitek) and light cured for 20 seconds in both groups. The SBSs were measured after 1000 cycles of thermocycling between 50C and 550C. Bond failure location was determined with the Adhesive Remnant Index (ARI).
Results: The mean shear bond strength was 9.01 MPa for the fluorosed teeth conditioned with SEP. This bond strength value was significantly different from bond strength values of fluorosed teeth conditioned with PA (15.22 MPa) and non-fluorosed teeth conditioned with SEP (12.95 MPa) and PA (15.37 MPa). ARI scores of fluorosed teeth conditioned with SEP showed a significant difference from the ARI scores of non-fluorosed teeth conditioned with SEP or PA.
Conclusion: The results of this in-vitro study suggest that the SEP (Transbond Plus) provides clinically acceptable bond strength values for the direct bonding of brackets to mildly fluorosed teeth (TFI = 1–3).