Clinical, Microbiological and Histological Effects of Cemented Implant Restorations. A Cross-over Controlled Clinical Study
Overview
- Phase
- Not Applicable
- Intervention
- Not specified
- Conditions
- Gingivitis and Periodontal Diseases
- Sponsor
- University of Zurich
- Enrollment
- 24
- Locations
- 1
- Primary Endpoint
- Analysis of microbiological parameters
- Status
- Completed
- Last Updated
- 3 years ago
Overview
Brief Summary
Abstract
Aim:
The primary aim of this study is to test whether or not cement residues in the submucosal environment of implants lead to a change in the microbiota and induce inflammation of the periimplant tissues.
Material and Methods:
24 patients in need of a single tooth replacement will be enrolled in this cross-over controlled clinical study. All patients will receive a two-piece dental implant, which will be restored with both a cemented and a screw-retained single crown. At the time of impression taking, patients will be randomized into two groups.
Patients in group A will receive a screw-retained crown. Every 8 weeks microbiological samples using sterile paper points will be collected and analyzed for bacterial content by real-time PCR. Additionally, two host markers (MMP8, IL-1ß) will be determined by ELISA. Following this first period of 16 weeks, the screw-retained crown will be replaced by a new intraorally cemented crown. Cement removal will be preformed according to best clinical procedure. These crowns will again be left for another period of 16 weeks and followed up for the harvesting of microbiological samples every 8 weeks. After the second 16-week the crowns will be removed to evaluate any excess cement. All patients will be fitted with the original screw-retained crown. Clinical parameters for inflammation and probing depths will be obtained after each 16 week-period.
In group B the crowns will be incorporated in a reverse pattern. During the first 16 weeks any possible cement residues will be removed according to best clinical procedure, while for the second period of 16 weeks patients will be fitted with a screw-retained single crown. Again, microbiological and clinical parameters will be obtained at the same intervals as in Group A.
After the second 16 week period the screw-retained crowns will be (re-) inserted in all patients, single tooth x-rays taken and clinical baseline values obtained. Additionally, a soft tissue biopsy will be harvested at the time of insertion of the final screw-retained crown. Patients will be followed up for another 16-week period.
Investigators
Eligibility Criteria
Inclusion Criteria
- •- patient older than 18 years
- •systemically healthy subject
- •periodontally healthy individuals
- •absence of peri-implantitis
- •no bone loss
- •good oral hygiene (PCR ≤ 20%)
- •healthy periodontal tissues (BoP≤ 20%)
- •patients with a single tooth gap in the posterior area of either jaw (premolars and molars)
- •at least 8mm in mandible; at least 6mm in maxilla (summers technique)
Exclusion Criteria
- •- ongoing periodontal disease
- •unwilling to comply with study procedures
- •heavy smokers (≥10 cig/d)
- •ongoing periodontitis/implantitis
Outcomes
Primary Outcomes
Analysis of microbiological parameters
Time Frame: Change BL to 16 weeks post-restoration
Change relative percentage of gram-negative microorganisms
Secondary Outcomes
- Histomorphometric analysis(32 weeks after BL)
- Immunohistologic analysis - putative periodontal pathogens(32 weeks after BL)
- Immunohistologic analysis - MMP8(32 weeks after BL)
- Immunohistologic analysis - IL1ß(32 weeks after BL)
- Analysis of inflammation markers on RNA-basis - (IL-4, IL-3, IL-1alfa, IL-1beta)(32 weeks after BL)
- Analysis of inflammation markers on RNA-basis - TNF-alfa(32 weeks after BL)
- Clinical parameters - Probing Depth(Every 8 weeks until 48 weeks and again at the 1-year follow-up)
- Clinical parameters - Bleeding-on-Probing(Every 8 weeks until 48 weeks and again at the 1-year follow-up)
- Clinical parameters - Plaque Index(Every 8 weeks until 48 weeks and again at the 1-year follow-up)