An invitro sudy on the flexural strength of porcelain veneers: Influence of preparation design and bonding agent

The objective of the research was to determine the role of preparation designs and bonding agents on the flexural strength of porcelain veneers. Forty-five intact human maxillary anterior teeth viz 15 central incisors, 15 lateral incisors and 15 canines were selected. Thirty six teeth were subjected to tooth preparation for veneers to be used for experiments. Nine teeth were kept to serve as controls. Of the thirty six teeth, eighteen were prepared with window design and eighteen with palatal overlap with chamfer margin. Veneers were prepared in IPS Empress Esthetic . For bonding, Variolink II and Metacem were used. The bonded specimens were subjected to mechanical flexural strength tests with Universal testing machine. All fractured specimens were subjected to scanning electron microscopy. Results of the study revealed that preparation designs viz. window preparation and palatal overlap with chamfer did not have variable influence on the flexural strength of the teeth restored with veneers. However the type of bonding cement influenced the flexural strength. Teeth bonded with Variolink II exhibited higher flexural strength compared to Metacem.