[Silane and bonding of resins to ceramic]

When bonding between two different dental materials is impossible due to structural dissimilarity, a third material can be used at the interface to achieve the desired bond. Silanes have been developed for this purpose and can improve bonding strength in dental restorations by preventing debonding at the interface region. The present study reviewed the relevant publications in order to determine the effect of silane on the bond strength of ceramic to resin restorations. Multiple internet search engines including Google, AltaVista, and the archives of related Journals were used in order to access information on the properties of silane. Application of silane increases the bonding strength between composite and resin by approximately 25%, regardless of different fabrication and testing methods. Etching with phosphoric acid and treatment with silane emerged as the two most significant factors in the improvement of the bonding strength of cements. However, using an appropriate coupling agent even without etching has also been shown to produce an acceptable bonding strength. Hydrolyzed silanes do not produce methanol and therefore cannot completely vaporize the water generated during chemical reactions. On the other hand, non-hydrolyzed silanes vaporize surface water by producing 3 methanol molecules and thus do not interfere with bonding of adhesive systems. Therefore the bonding strength of non-hydrolized silanes is greater than hydrolyzed silanes. In conclusion, the type of silane [hydrolyzed, non-hydrolyzed], the adhesive used and the technique of its application are considered to be three of the most important factors affecting bond strength