INTRODUCTION: The laminate veneer technique bonds a thin ceramic laminate to the tooth surface with resin cements to restore anterior teeth. A vital importance is attributed to the strength and durability of the adhesion complex.
OBJECTIVES: The aim of this study was to evaluate the shear bond strength of ceramic laminate veneers to two different tooth substrates (Enamel and Enamel–Dentine complex), with different luting systems.
MATERIALS AND METHODS: Sixty extracted human maxillary central incisor teeth were used, and randomly divided according to tooth surface preparations into two main groups (n=30); Group A in Enamel (E) only and Group B in Enamel-Dentin complex (E-D), each group was then subdivided according to the type of resin cement received (Light cure LC or Dual cure DC) into four sub groups of 15 specimens each: Group A 1:(E + LC); Group A 2:(E + DC); Group B 1:(E-D + LC); Group B 2:(E-D + DC). Ceramic discs (IPS e.max Press, IvoclarVivadent) of 4 mm in diameter and 2 mm in height were luted to the tooth surfaces by using the resin cement (Variolink Esthetic®, IvoclarVivadent) according to the manufacturers' instructions. Shear bond strength test was performed in a universal testing machine at 0.5 mm/min until bonding failure. Failure modes were determined under a stereomicroscope, and fracture surfaces were evaluated with a scanning electron microscope. The data were statistically analyzed (p≤0.05).
RESULTS: Group B 1 exhibited the lowest bond strength value(9.12±4.86MPa). There was statistically no difference among A 1,A 2 and among B 1,B 2(p>0.05).Group A 2 exhibited the highest bond strength value (14.73± 5.83MPa).
CONCLUSIONS: The type of tooth substrate affected the shear bond strength of the ceramic laminate veneers to the 2 different types of tooth structures (Enamel, Enamel–Dentine complex).