Ceramic surface treatment methods prior to orthodontic bonding

Aim: To present a current review on the possible methods of surface treatment of porcelain prior to orthodontic bonding.
Methods:Since the ceramic structure is inert, numerous methods of surface treatment have been attempted to improve the bond strength of orthodontic attachments to ceramic surface. These methods could be mechanical or chemical or combination. This review discusses these different methods to help guide the orthodontist which method is suitable and provide the clinically adequate bond strength.
Results: Mechanical preparation of the porcelain surface results in permanent destruction to the porcelain glaze and compromise the original luster and integrity of the ceramic surface. Laser application to the ceramic surface has also been studied as a possible surface treatment procedure. However, it is a highly costly technique. Conditioning the porcelain surfaces with 37% phosphoric acid (PA) followed by a silane coupling agent produced clinically acceptable bond strength.  It has been suggested to use PA as a substitute to hydrofluoric acid  (HFA) etching in a trial to promote adhesive failure due to the expected lower bond strengths and thus decrease the risks to the ceramic surface. Silane coupling agents have been documented to improve bond strength to porcelain substrates.
Conclusion: There are different methods for surface treatment of porcelain prior to orthodontic bonding. According to this review the most suitable less destructive method to the porcelain following debonding is using 37% PA followed by silane application as it can produce clinically accepted bond strength as proved in the literature. Yet, continuous development of new surface treatment methods and materials is highly important.