Effect of the Abutment-Prosthesis Connection on Marginal Bone Loss and Gingival Sealing Around Dental Implants

Study Overview
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Brief Summary
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In dental implant restoration, available literature demonstrates the advantage of using tall abutments, with a change of diameter with respect to the implant and a conical internal connection in the abutment-implant gap. However, for multiple restorations, the abutment-prosthesis connection has not been studied in detail. The multi-unit systems, both standard and brand specific, have either a flat or butt joint or an cone. In any case, both are external connection systems. Recently, an internal-type abutment-prosthesis connection system has been developed. Although it is proving its usefulness in single restorations, its use in multiple restorations compared to traditional systems has not been studied. Therefore, taking into account all of the above, the present study has the overall objective of analyzing marginal bone loss (MBL) and adaptation of soft tissues by comparing a multiple prosthesis system of the external, flat type versus an external system of the internal, conical type.

Official Title
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Effect of the Abutment-Prosthesis Connection on Marginal Bone Loss and Gingival Sealing Around Dental Implants

Conditions
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Jaw, Edentulous, Partially

Intervention / Treatment
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* Device: Connect®
* Device: Multi-unit


Participation Criteria
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Eligibility Criteria
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Inclusion criteria: Kennedy class I or II (unilateral or bilateral free end) or III (posterior intermediate edentulous section) mandibular requiring 2 implants to restore at least 2 molars, 2 molars and 1 premolar, or 2 premolars and 1 molar. Possibility of placing a transgingival abutment at least 2 mm high. Exclusion criteria: Need for simultaneous bone augmentation. Heavy smokers (>10 cigarettes/day). Uncontrolled type 1 or 2 diabetes (HgA1c>8). Known autoimmune or inflammatory disease. Serious blood disorders, such as hemophilia or leukemia. Local or systemic infection that may compromise normal healing (e.g., extensive periapical pathology). Liver or kidney dysfunction/failure. Currently receiving cancer treatment or within 18 months from completion of radio- or chemotherapy. Long-term history of oral bisphosphonates use (i.e., 10 years or more). History of intravenous bisphosphonates. Long-term (>3 months) history of antibiotics or drugs known to alter the inflammation and/or immunological system 3 months before inclusion. Severe osseous diseases (e.g., Paget disease of bone). Pregnant women or nursing mothers. Not able or not willing to follow instructions related to the study procedures.

Ages Eligible for Study
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Minimum Age: 18 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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Design Details

Primary Purpose: Treatment
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Single


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Connect®<br>Restoration of multiple implants with a Connect® abutment between the implant and the prosthesis. | Device: Connect®<br>* Restoration of multiple implants with a Connect® abutment between the implant and the prosthesis.<br>|
| Active Comparator: Multi-unit<br>Restoration of multiple implants with a conventional multi-unit abutment between the implant and the prosthesis. | Device: Multi-unit<br>* Restoration of multiple implants with a conventional multi-unit abutment between the implant and the prosthesis.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Marginal bone level | Peri-implant marginal bone level measured by standardized periapical radiography | 1 year | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Peri-implant microbiome | Relative abundance of microbial species in the peri-implant sulcus evaluated by next-generation sequencing methods | 1 year | 
| Peri-implant inflammation | Concentration of pro-inflammatory markers in the peri-implant sulcus evaluated by multiplex techniques methods | 1 year |