2Q1B. Placing Orthodontic Brackets

Placement of bracket by composite resin:

 

Placement of brackets on teeth is a multiple step process very much like placement of white restoration on a tooth. Effectively, brackets are “glued” onto the tooth by a thin layer of white restoration material.

 

During the placement of the brackets, the teeth surfaces will be chemically prepared for bonding of the bracket. After the initial step, the teeth surfaces must be kept dry and not contaminated with saliva. Patients should not touch their teeth surfaces with their tongue and to try to breath through their nose to minimize condensation.

 

The process of bracket placement is as follows:

  • Use of phosphoric acid to prepare tooth surfaces for attachment.
  • Rinsing of teeth to wash away the phosphoric acid.
  • Placement of bonding agent (unfilled resin) to properly “wet” the enamel surface to increase the surface area of attachment with the filled composite resin.
  • Placement of the bracket with resin placed on its base.
  • Application of blue light to bonding materials to catalyze the curing of the material to a hard set. (Bonding materials contain blue - light sensitive chemical activator that initiate reaction to harden the bonding material)

Beside the traditional resin composite bonding material there are also resin-glass ionmer material that can be used to bond brackets onto teeth. Resin-ionmer does not form as strong of a bond as normal composite. However, it does have two major benefits:

  • Resin ionmer slowly releases fluoride ion which may decrease the risk of white spot lesions and tooth decays.
  • Because of its material property, resin ionmer can bond to a tooth surface even if the surface is slightly wet. This property of the bonding material makes it easier to bond posterior teeth and less bonding failure from saliva contamination.

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