A comparative evaluation of shear bond strength of directly bonded brackets using three varieties of light cure systems: An in-vitro study

Context: Using Visible Light to bond orthodontic attachments is now an accepted norm, the progression being  Halogens, Low and High Intensity Light Emitting Diodes (LEDs). Since, clinical use of bonded brackets is pragmatically linked with Shear Bond Strength (SBS) and chair-side time, adhesives with shorter curing time are a boon. Hence, the aforementioned facets bear a more detailed study. Settings and Design: 6 Groups (2 Halogens, 2 Low Intensity LEDs and 2 High Intensity LEDs); Each Group comprised of 10 assemblies of Metal Brackets (3M Unitek, Gemini Series) bonded to facial surface of extracted human Maxillary 1st bicuspids. Methods and Material: Brackets were directly bonded using Standard Bonding Protocol to freshly extracted Human Maxillary Premolars. Shear Bond Strength (SBS) testing was done using Universal Testing Machine, Instron. The SBS values attained in Kg/F were converted into MPa and results subjected to a comparative evaluation. Results: Mean SBS values, in MPa, for Halogen Light Cure Systems were 8.51 and 8.86; for Low Intensity LEDs were 10.50 and 10.33 while for High Intensity LEDs 15.54 and 13.85.&nbsp