Wear Behavior of Milled Posterior Crowns Fabricated From the New Monolithic Zirconia 5Y-TZP/3Y-TZP Compared to Lithium Disilicate

Study Overview
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Brief Summary
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In-vitro studies do not represent the actual masticatory environment and cannot simulate the intricate chewing pattern. Hence, there is a need for an in vivo study evaluating the wear potential of the newly introduced strength - color gradient multilayered zirconia IPS e.max ZirCAD Prime (5Y-TZP/3Y-TZP) and compare it to Lithium Disilicate IPS e.max CAD which has proven to have favorable wear patterns.

Detailed Description
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There will be no difference in wear caused by monolithic Zirconia (5Y-TZP/3Y-TZP) IPS E-max ZirCad Prime and Lithium Disilicate IPS e.max CAD to the antagonist. There will be no difference in the wear of the new monolithic zirconia IPS e.max ZirCAD Prime and lithium disilicate IPS e.max CAD.

Official Title
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Wear Behavior of Milled Posterior Crowns Fabricated From the New Gradient Technology Monolithic Zirconia 5Y-TZP/3Y-TZP Compared to Lithium Disilicate: (Randomized Clinical Trial)

Conditions
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Posterior Teeth, Worn Posterior Teeth, Endodontically Treated Teeth, Crowned Posterior Teeth

Intervention / Treatment
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* Other: monolithic zirconia (5Y-TZP/3-YTZ) ZirCAD Prime.
* Other: Lithium Dislicate IPS e.max crown


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: All subjects are required to: 1- Be aged 21-50 years old, be able to read and sign the informed consent document. 2- Psychologically and physically able to withstand conventional dental procedures. 3- Patients with mutilated posterior teeth indicated for full coverage restorations. 4- Patients with sound natural antagonists. 5- Able to attend punctually for preplanned visits and evaluation. 6- Have no active periodontal or pulpal diseases. 7- There should be no apparent loss or wear in opposing enamel. Exclusion Criteria: Patient with active resistant periodontal diseases. Patients with parafunctional habits and bruxism. Patients with poor oral hygiene, high caries risk and uncooperative patients. 3- Pregnant women. Patients in the growth stage with partially erupted teeth. 5- Psychiatric problems or unrealistic expectations. 6- Lack of opposing dentition in the area of interest. 7- Restored occlusal surface opposing the planned restoration. 8- The presence of a removable or fixed orthodontic appliance.

Ages Eligible for Study
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Minimum Age: 21 Years
Maximum Age: 50 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Other
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Double


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Active Comparator: Lithium Disilicate IPS e.max crowns in posterior teeth<br> | Other: Lithium Dislicate IPS e.max crown<br>* wear of lithium disilicate IPS e.max crown in posterior teeth<br>|
| Experimental: Monolithic Zirconia (5Y-TZP/3-YTZP) crowns in posterior teeth<br> | Other: monolithic zirconia (5Y-TZP/3-YTZ) ZirCAD Prime.<br>* wear of the new material of monolithic zirconia (5Y-TZP/3-YTZ) ZirCAD Prime in posterior teeth<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| The amount of occlusal wear in natural antagonist enamel caused by the restorative material | The amount of occlusal wear in natural antagonist enamel, using digital superimposition of model scans after 1 year, measured in micrometer. | 1 year | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| The amount of occlusal wear in the restorative material itself | The amount of occlusal wear in the restorative material itself, using digital superimposition of model scans after 1 year, measured in micrometers. | 1 year |