Prosthetic Outcomes and Clinical Performance of Implant Supported Zirconia Crowns

Prosthetic Outcomes and Clinical Performance of Two Types of Monolithic Zirconia-based Screw-retained Crowns. A Randomized Clinical Trial

To compare biological, technical, radiographic, and patient-reported outcomes of two types of monolithic zirconia crowns screw-retained to implant.

To assess whether the new form of multilayered zirconia crowns will show similar survival and success rate to conventional monolithic Zirconia screw-retained to implants in molar and premolar regions.

First Null Hypothesis: Multilayered monolithic zirconia crowns would have similar survival, success rate compared to conventional monolithic zirconia implant supported crowns.

Second Null hypothesis: There would be no difference in clinical and patients related outcomes between multilayered and conventional monolithic zirconia implant supported crowns.

Study design:

A short-randomized controlled trial study, the (PICO) study design: population will be patients from Jordan University Hospital with implants planned for single screw-retained zirconia crowns in the posterior site (premolar or molar), intervention will be the multilayer monolithic screw-retained zirconia crowns over implants, the comparator is the conventional monolithic zirconia crowns over implants, and the main outcomes will be the prosthetic/technical outcomes, survival and success rates in addition to radiographic, patient-reported outcomes, and biological parameters.

Methodology The patients who fulfilled the inclusion/exclusion criteria and entered the study will have a fully digital workflow starting from data acquisition using an intraoral scanner (3Shape TRIOS® 5) , Ti-base abutment design and CAD/CAM milling of the two types of monolithic zirconia blanks (IPS e.max® ZirCAD Prime and IPS e.max® ZirCAD LT).

The fabricated zirconia crowns in both groups will have the same treatment and will be cemented to the Ti-base abutment according to the (APC) concept; alumina airborne-particle abrasion 50-μm at 1 bar for 15-20 seconds, intaglio surface primed using MDP for 60 seconds and air blown for 5 seconds, and finally cemented to the abutment by phosphate monomer resin cement PANAVIA™ V5(Blatz-Alvarez-Compendium-APC-2016, n.d.).

On the other hand, the Ti-base abutment: height will be standardized at 4mm, and the base abutment surface will have blasting with alumina particles of 50 μm at 2-bar pressure for 15-20 seconds at a 10-mm step-over distance at an angle of 45 degrees.

Inclusion Criteria:

• Partially edentulous area with suitable restorative space more than 5.5 mm
• At least 18 years of age
• Opposing natural teeth or fixed restorations supported by teeth or implants.
• Generally good health (ASA I, ASA II)
• Participant complies with good oral hygiene practices (BOP and PI less than 20%)
• Healthy integrated implant/s without signs of periimplantitis in the posterior site planned for single tooth replacement (in premolar or molar areas)
• Patients received bone-level implants, RC Straumann Implants.

Exclusion Criteria:

• Inability to provide consent.
• Temporomandibular disorders
• Smoking of more than 10 cigarettes per day
• Untreated caries or periodontal disease of remaining dentition