Comparison of Self-Adhesive Resin, Conventional Glass Ionomer, and Bioactive Resin-Modified Glass Ionomer Cements for Prefabricated Zirconia Crown Retention in Primary Anterior Teeth: A Randomized Controlled Trial

This prospective, parallel-group, three-arm, randomized controlled trial evaluates the long-term clinical performance of three commercially available luting cements when used to bond prefabricated zirconia crowns (PZCs) on primary anterior teeth in pediatric patients. Although PZCs are increasingly preferred over stainless steel crowns for anterior restorations due to their superior esthetics and biocompatibility, their retention relies entirely on the luting cement because of their passive fit and conservative preparation design. Comparative clinical evidence on cement performance in this specific anatomical and functional context remains limited.

Trial Design:

The trial is conducted at the Pediatric Dental Clinic of Qassim University, Riyadh, Saudi Arabia. Eligible children aged 2 to 7 years requiring full-coverage restoration of one or more primary incisors are randomized in a 1:1:1 ratio to one of three cement groups using a computer-generated randomization sequence. Allocation labels are reshuffled after each assignment to preserve equal group sizes. An independent outcome assessor is blinded to group allocation throughout the trial, and standardized cheek retractors are used to mask cement margins during evaluations. Operators cannot be blinded due to material-specific application protocols.

Intervention Protocols:

Tooth preparation follows standardized anterior-specific minimal reduction principles (1.0-1.5 mm incisal, 0.5-0.8 mm uniform labial, feather-edge proximal margins) under rubber dam isolation. NuSmile® prefabricated zirconia crowns are used for all participants. Cement application follows manufacturer instructions for each group: