Clinical Study of a 3D Shaded Zirconia for Chairside CAD/CAM Restorations

The primary aim is:

▪ Evaluate the longitudinal clinical performance of 3D shaded zirconia onlays, crowns, and fixed partial denture (FPD) over five years of clinical service. The restorations will be evaluated with modified FDI criteria for maintaining their esthetic, functional and biological properties.

The secondary aims are:

• Evaluate the resistance to material chipping and fracture of reduced thickness zirconia chairside computer assisted design and computer assisted machining (CAD/CAM) onlays, crowns, and fixed partial dentures (FPDs).
• Evaluate the short-term post-operative sensitivity associated with cementation techniques using a self-adhesive, universal resin cement and a selective etch/universal bonding agent with a universal resin cement.

Inclusion criteria

• Adult aged 18-75 years.
• Willing and able to sign and date the informed consent form and the HIPAA form.
• Onlays and Crowns: Each patient should have at least one carious lesion, defective restoration, or fractured portion of the tooth to be restored on a maxillary or mandibular premolar or molar tooth. Each lesion, fracture, or defective restoration should exhibit sufficient size or loss of tooth structure requiring an onlay or crown restoration. The tooth should have at least one opposing tooth in occlusion and one adjacent tooth with an intact proximal contact. No more than eight teeth that are endodontically treated and restorable with an onlay or crown may be included in the study. All remaining teeth in the study will test vital and be asymptomatic at the beginning of treatment. No more than two restorations will be placed per patient. If a patient presents with more than two acceptable teeth for the study, molar teeth will be included prior to premolar teeth.
• Fixed Partial Dentures (FPDs): Each patient should have at least one missing tooth, either anterior or posterior, that is appropriate for replacement with a fixed partial denture. Abutment teeth will have healthy periodontal status with at least a 1:1 crown:root ratio. The FPD should have at least two opposing teeth in occlusion and one adjacent tooth with an intact proximal contact. Both abutment teeth must be asymptomatic prior to treatment. Endodontically treated teeth will be acceptable for abutments if nonmetallic cores can be placed to retain the FPD. FPDs may include 3 or 4 teeth as indicated by the clinical situation but must be within the 43 mm span of the mill block to manufacture it as described later. The patient cohort should include a mix of non-endodontically as well as endodontically treated teeth.

Exclusion criteria

• Unlikely to be able to comply with clinical study procedures, according to Principal Investigator's (PIs) judgment.
• Subject is not willing to participate in the clinical study.
• Patients unable to return for the recall appointments for a period of 5 years.
• Severe non-compliance to the clinical study plan as judged by the PI and/or Dentsply Sirona.
• Involvement in the planning and conduct of the clinical study. Applies to both Dentsply Sirona personnel and personnel from the clinical study site.
• Sensitive teeth.
• Teeth diagnosed with symptoms of incomplete tooth fracture.
• Teeth with a history of direct or indirect pulp capping procedures.
• Patients with significant untreated dental disease to include periodontitis and/or rampant caries.
• Women who self-report that they are possibly pregnant, pregnant, or lactating, as elective dental treatment is not indicated at these times.
• Patients with a self-reported history of allergies to the materials to be used in the study including composite resin cements, provisional acrylics, or zirconia restorative materials.