Implant Supported Single Crowns With Different Retention Modes

Study Overview
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Brief Summary
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This study aims to examine the inflammatory response mediated by MMP-8 (Matrix metalloproteinase-8 ) level in peri-implant sulcus fluid adjacent to screw-retained, cemented or using the Acuris-system fixed single implant crowns as well as changing of the marginal bone level within the first year after implant restoration. Furthermore periodontal parameters, patient satisfaction and possible occurring biological or technical complications will be evaluated.

Detailed Description
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After giving their written consent volunteers will be screened and eligible subjects will be randomized to three different groups. In group 1 Acuris® is used as fixation type; in group 2 screw retention, and in group 3 cementation is used. After 3 months of submerged healing the dental implants will be restored with all ceramic single implant crowns, fixed by using the randomized fixation mode. Follow-up visits till one year after implant restoration will be performed. At least 11 study visits during 16 months will be conducted.

Official Title
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Implant Supported Single Crowns With Different Retention Modes - Effects on Peri-implant Tissue: A Prospective Randomized Controlled Clinical Trial

Conditions
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Complications: Inflammatory Reactions, Mechanical Complications

Intervention / Treatment
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* Other: conometric concept Acuris system
* Other: screw retention
* Other: cementation


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: capability of giving an informed consent good health as defined by the subjects medical history (no contraindications as described in the exclusion criteria below) age 18 to 99 years Good periodontal status: BOP < 20%, PI < 30%, no PD > 4mm No heavy smokers (< 10 cigarettes/day) at least 1 missing tooth in the premolar and molar region (with at least a mesial neighboring tooth/implant showing adequate hard- and soft tissue situation without the need of crestal hard- or soft tissue augmentation) either in the maxilla or in the mandible requiring implant therapy for reconstruction, requiring sinus floor augmentation or not. Exclusion Criteria Insufficient bone volume for implant placement requiring GBR (guided bone regeneration) procedure in crestal area. Heavy Smokers (>10 cigarettes/day) Medication with a contraindication for implant therapy (especially antiresorptive therapy, ongoing or recently completed local radiotherapy, systematic diseases, ongoing immunosuppressive therapy, functional disorders like Bruxism). Skeletal immaturity. Any active malignancy or ongoing treatment for malignancy. An active infection (e.g. caries, gingivitis, periodontitis) at or in the neighboring area of the operative site. Pregnancy unable or unwilling to return for follow-up visits for a period of at least 16 months

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 99 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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Design Details

Primary Purpose: Treatment
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: conometric concept (Acuris system)<br>single implant crown retention using friction only | Other: conometric concept Acuris system<br>* implant crown retention type using friction only<br>|
| Active Comparator: screw retention<br>screw retained implant Crown fixation | Other: screw retention<br>* screw retained implant crown<br>|
| Active Comparator: cementation<br>cement retained implant Crown fixation | Other: cementation<br>* cement retained implant crown<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Change of marginal bone level | assessed by single tooth x-ray; in mm | at baseline, 4 months after implant placement and 3, 6 and 12 months after restoration | 
| Change of matrix metalloproteinase 8 level | biomarker for Inflammation of peri-implant disease; in ng/ml | 4 months after implant placement, 3, 6 and 12 months after integration of the implant crown | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Change of probing depth (PD) | using a periodontal probe; in mm | at baseline, 4, 7, 10, 16 months after implantation | 
| Number of occurrences of chipping | visual check | measured after integration of implant crown 3, 6 and 12 months after restoration | 
| soft tissue maintenance | Papilla Index (Jemt T, 1997), the index ranges from 0 to 4, while 2 and 3 indicate physiological outcome | measured 4 months after implant placement and 3, 6 and 12 months after restoration | 
| technician satisfaction | evaluated using an individual questionnaire | measured 12 months after restoration | 
| dentist satisfaction | evaluated using an individual questionnaire | measured 12 months after restoration | 
| patient satisfaction | evaluated using OHIP-G 14 questionnaire. The following dimensions are captured by the OHIP-G 14: functional Limitation (e.g., pronouncing any words because of problems with your teeth, mouth, dentures, or jaw?) and physical Pain (e.g., Have you had painful aching in your mouth). 14 questions are raised, which are answered using a rating scale from 0 (never) to 4 (very often). | measured at baseline, 3 and 12 months after restoration | 
| Plaque Index (PI) | in percent | at baseline, 4, 7, 10 and 16 months after implantation | 
| Bleeding on Probing (BOP) | in percent | at baseline, 4, 7, 10 and 16 months after implantation | 
| Patient satisfaction concerning the implant crown | evaluated using an individual questionnaire | measured 12 months after restoration | 
| Number of occurrences of fractures | visual check | measured after integration of implant crown 3, 6 and 12 months after restoration | 
| Number of occurrences of screw loosening | visual check | measured after integration of implant crown 3, 6 and 12 months after restoration | 
| Number of occurrences of crown loosening | visual check | measured after integration of implant crown 3, 6 and 12 months after restoration | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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MMP-8, marginal bone level, conometric concept - Acuris, crown retention, all-ceramic crown