Survival of Hybrid Laminate Veneers Using Two Different Tooth Preparation Techniques:Randomized Clinical Trial

The aim of this study was to evaluate the survival of laminate veneers constructed using a recent polymer-infiltrated ceramic network material following the aesthetic pre-evaluative temporary (APT) technique of tooth preparation in comparison to traditional technique.

Six recruited patients (4 females, 2 males; ranging from: 20-30 years old and with mean age 24.6 years), who needed indirect laminate veneer restorations were included in this study. Patients were selected from the outpatient clinic of the Department of Fixed Prosthodontics,Faculty of Dentistry, Cairo University The participants received a total of 54 laminate veneers between April 2017 and February 2018. Written informed consent was acquired from all participating patients. Randomization was done using a computer generated 2 column list by the aid of Random.org in a 1:1 ratio. Allocation concealment was achieved using numbered cards in opaque sealed envelopes. Aluminium foil was placed inside the envelope to render the envelope impermeable to intense light. These envelopes were placed in a box and each participant was allowed to grasp one envelop the day of operation. Allocation concealment was performed by an investigator with no clinical involvement in the trial. This study is a single blinded study as the assessor was blinded to the assigned study groups. Blinding of the participants was not applicable as one of the techniques required extra visits. Blinding of the operator was not applicable as one clinician performed the tooth preparation in both techniques.A total of 54 laminate veneers were divided into two equal groups (n=27) according to the technique of tooth preparation: group T: traditional technique and group A: aesthetic pre-evaluative temporary technique. VITA ENAMIC material was used for CAD/CAM construction of laminate veneers. Cementation was performed using a light cured resin cement. The laminate veneers were evaluated at baseline, after 3, 6 and 12 months according to the modified United States Public Health Service (USPHS) criteriea. The data was collected, tabulated and statistically analyzed.

Eligibility Criteria:
Inclusion Criteria:

* Patient-related criteria:

  * Patients consulting the outpatient clinic of the department of Fixed Prosthodontics, Faculty of Dentistry, Cairo University.
  * Able to tolerate necessary restorative procedures.
  * Provide written consent.
  * Accepts the one year follow-up period.

Tooth related criteria:

* Malaligned and malformed teeth in the aesthetics zone
* Multiple spacing
* Diastema
* Slightly and moderately discolored teeth
* Good oral hygiene

Exclusion Criteria:

Patient-related criteria:

* Medically compromised patients, as they would not be able to attend multiple appointments or might require special management.
* Uncooperative patients, who would not abide by the instructions or attend the appointments.

Tooth related criteria:

* Deciduous teeth; as the study was targeting only permanent teeth.
* Teeth with previous restorations, which might add another variable to the study (type of old restorative material, extent of recurrent caries). This could also affect the bond of laminate veneers to tooth structure.
* Patients with parafunctional habits, large restorations, or excessive tooth wear.
* Initially, scaling and polishing was performed. Patients were instructed on improving their oral hygiene and maintaining effective plaque control. However, if their gingival health did not improve, they were excluded from the study.