Survival of Implant-Supported All-Ceramic Prostheses

Study Overview
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Brief Summary
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The purpose of this research study is to identify reasons that cause an all-ceramic bridge to fracture which include the thickness of the bridge material, the type of bridge material and the bite force of the person. This all-ceramic bridge will be compared to a metal-ceramic bridge. The investigators are conducting this study so we can make bridges which can withstand forces in the mouth which tend to break them. The overall objective of this research is to analyze how properties of ceramic materials and different forces in the mouth interact with each other to affect the longevity of these bridges. These include fracture toughness, elastic modulus of ceramic layers and supporting substrate, core thickness, connector height, wear, loading orientation, and maximum clenching force.

Detailed Description
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The long-range goal of the proposed research is to formulate design survival statistics that will aid the dental community in fabricating properly designed prostheses that can predictably survive the oral environment. Patients who qualify for this study will be randomized (as in chanced with the flip of a coin) into two groups. The first group is a metal-ceramic group where patients will receive a bridge with a metal substructure underneath. The second group is an all-ceramic group where patients will receive a bridge which is made of hard ceramic material. All patients will receive two dental implants which will bond to bone for a period of 4-6 months. An impression or mold of the implants will then be made and a bridge will be fabricated based on the randomization of the patient. Patients will be asked to return at 6 months and yearly thereafter up to 5 years. During these recall appointments, photographs will be taken and impressions of the bridge and other teeth will be made. This will allow us to measure the amount of wear happening with the bridge and the other teeth. The investigators can also examine the amount of bone around the implants as well as the integrity of the bridge.

Official Title
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Factors Influencing the Survival of Implant-Supported All-Ceramic Prostheses

Conditions
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Partial Edentulism, Disorder of Prostheses and Implants, Dental Prosthesis Failure

Intervention / Treatment
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* Device: Ceramic-Ceramic
* Device: Metal-Ceramic


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Aged between 21-75 years, and no contraindications to dental treatment. Good overall dental health, no active caries, no periodontal disease, and periodontal pocket depths not greater than 4 mm. Missing at least three teeth in the posterior area of the mouth. Natural teeth opposing the edentulous area and a full complement of teeth or restored teeth in all other areas of the mouth Adequate bone height and width at areas of proposed implant sites Adequate interocclusal distance to accommodate prosthesis Good oral hygiene and compliance with oral hygiene instructions as determined by the amount of plaque present on tooth surfaces. Compliance with appointments and willing to pay $2625 for a 3-unit implant supported FDP Exclusion Criteria: Non compliance Not enough teeth remaining Uncontrolled medical condition

Ages Eligible for Study
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Minimum Age: 21 Years
Maximum Age: 75 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Metal-Ceramic<br>Metal Ceramic prosthesis with press on veneer with different thicknesses, different diameters of curvature of gingival embrasure and connector heights. | Device: Metal-Ceramic<br>* Metal Ceramic prosthesis with press on veneer with different thicknesses, different diameters of curvature of gingival embrasure and connector heights. Fifty percent of the recruited subjects will receive the metal-ceramic bridges at baseline.<br>|
| Ceramic-Ceramic<br>Zirconia computer aided design and computer milled cores with press on veneers with different thicknesses, gingival embrasure diameters and connector heights. | Device: Ceramic-Ceramic<br>* Zirconia computer aided design and computer milled cores with press on veneers with different thicknesses, gingival embrasure diameters and connector heights. Fifty percent of the recruited subjects will be given a ceramic-ceramic bridge at baseline.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Fracture | Any fracture or chipping of the prostheses reported by the participant or noted at recall periods | A change from baseline to year 5 | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Wear of prosthesis and enamel antagonist | Wear of the prosthesis and the opposing enamel will be assessed at the recall appointments | 6 mos, 1 year, 2 year, 3 year, 4 year, 5 year |