One Year Clinical Evaluation of E.Max Laminate Veneers With and Without Using Grape Seed Extract as a Natural Collagen Cross-linking Agent Before Bonding

Justification for undertaking the trial:

Ceramic veneers have become a popular dental procedure since its introduction because they provide excellent esthetics.1 Achieving the good esthetic results especially with ceramic veneers is probably the most challenging task encountered by dental practitioners and ceramist today. Ceramic veneers are indicated for teeth with moderate discoloration, restoration of traumatized, fractured, worn dentition and abnormal tooth anatomy.2 Many factors affect the long term success of ceramic laminate veneers. The most repeated failure patterns associated with ceramic laminate veneer were fractures, microleakage, colour change and detachment of restoration.3 The main reasons for failure were large marginal defect and fractures.4 The clinical performance of ceramic veneer has shown that the estimated survival rate for the teeth prepared with butt joint design are higher than for the teeth prepared with palatal chamfer design.5 The bonding technique, which is a time-consuming and technique sensitive procedure, is a key to the long-term success of these types of restorations. The strength and the durability of the bond between the porcelain, the luting cement and the enamel/dentin interface play an important role in the outcome of ceramic veneers, particularly when dentin is involved. 6

Expected benefits for the patient

1. Achieving a more predictable esthetic restoration while being conservative. 2. Increasing the long term prognosis of the restoration. Expected benefits for the clinician

1. Enriching the professional skills of the dentist with a new material to improve the clinical performance of the restoration.
2. Improving the confidence in the patient-dentist relationship.

Explanation for Choice of Comparators Resin cements are generally used for the bonding of all ceramic restorations since they provide adequate aesthetics, low solubility in oral environment, high bond strength to tooth structures, superior mechanical properties and support for ceramic.7 Since their retention relies solely on adhesion, durable adhesion of resin luting cements to both the enamel/dentin and the cementation surface of the ceramic is crucial. Luting cements used in conjunction with phosphoric acid etching followed by adhesive application on enamel show reliable adhesion.8 By studying the effect of incorporation of natural cross-linkers into the primer of a self-etching adhesive on resin-dentine bond strength, it had a positive influence on the immediate μTBS (micro tensile bond strength) and mechanical properties of the bonded interface.9

Statement of problem:

Ceramic veneers have become a popular dental procedure since its introduction because they provide excellent esthetics while being conservative. However, high failure rates of PLVs have been attributed to the exposure of dentin surface during preparation which greatly decrease the bonding strength at the dentin-cement interface. Natural and synthetic cross-linking agents have been introduced to restore dentin function, enhance bonding strength as well as positively affect the remineralization process in artificial roots. They have the ability to enhance the mechanical properties and stability of dentin matrix by the use of PA-rich collagen cross-linkers most likely due to the formation of a PA-collagen complex.10

Research hypothesis The null hypothesis of the study that there won't be a difference in the clinical performance \& adhesion of laminate veneers after application of grape seed extract before bonding.