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The most important procedures in orthodontic practice is bonding brackets to tooth enamel. The adhesive force should be enough to keep the bracket in position throughout the orthodontic treatment, but not strong enough to cause damage on its debonding to the enamel. Lopez, as well as Reynolds, suggests that shear strength should be 6-8. [1] Equivalent traction would be about 5 MPa.Since the inception of lingual orthodontics, it was necessary that orthodontist had to think of an optimal straight wire technique because of the reduced interbracket span on the lingual surfaces with its associated biomechanical consequences and the problems encountered while working on the lingual surface and also because of the anatomical irregularities of the teeth on that side. The introduction of computer-aided design/ computer-aided manufacturing (CAD/CAM) technology has made it possible to produce brackets with an adaptable base and with the necessary precision for all lingual surfaces, also it became obvious that there was a need for indirect bonding involving bracket positioning on cast models. Three popular indirect bonding systems are the Torque Angulation Reference Guide (TARG), Class and Pacon systems.Shear bond strength (SBS) is the main factor, which has to be considered in the evolution of bonding materials. The bond strength of the orthodontic bracket must be able to withstand the forces applied during the orthodontic treatment.

The intrinsic hardness, high abrasive wear resistance, and corrosion properties of hard chrome coatings have resulted in their wide industrial application. However, chrome plating involves hazards associated with chrome 6+ which affect human health and drive the need to identify viable alternatives. This study investigated the addition of Cirrus alumina Dopant™ to a low phosphorus electroless nickel bath to evaluate the performance of the resulting nanocomposite coating as a potential replacement for hard chrome. A comprehensive comparison for the performance of coatings for alumina doped electroless nickel and a pure low electroless nickel coating were investigated. Results showed that Cirrus doped electroless nickel possessed a minimum hardness of 850HV0.1, high corrosion resistance, excellent abrasive wear resistance, and a Taber Wear Index of 2.25mg/1000 cycles. These attributes suggest Cirrus Dopant™ for electroless nickel may offer an outstanding candidate to replace hard chrome coatings in many applications.

Background: The present study was conducted for assessing the impact of fixed orthodontic treatment on salivary nickel levels. Materials & methods: A total of 20 subjects who were scheduled to undergo fixed orthodontic treatment were enrolled in the present study. Complete demographic details of all the subjects were obtained. A Performa was made and complete clinical findings of all the subjects were recorded. At baseline (during the start of fixed orthodontic treatment), salivary samples were obtained and salivary nickel levels were evaluated using an autoanalyzer. Same procedure was repeated on regular follow-ups and salivary nickel levels were assessed. All the results were recorded in Microsoft excel sheet and were analyzed by SPSS software.  Results: Mean salivary nickel levels at baseline, 6 months follow-up and 1 year follow-up was 8.9 μg/L, 11.3 μg/L and 8.5 μg/L respectively. Significant results were obtained while comparing the mean salivary nickel levels at different time intervals. Conclusion: It could be concluded that orthodontic therapy for longer durations with sstainless-steel archwires might elevate slightly, but significantly, salivary nickel levels.