Bacterial Microbiota Characterization on Implant-supported PEEK and Titanium Provisional Abutments

Study Overview
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Brief Summary
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The aim of this study is to determine the relative abundances of the different bacterial phyla and families in the microbiota present on the surface of PEEK implant-supported provisional abutments compared to titanium implant-supported provisional abutments, as well as the effect of both materials on the presence of antibiotics resistance genes.

Detailed Description
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The use of provisional abutments is mandatory during the restorative phase of any implant based oral rehabilitation. The introduction of poly-ether-ether-ketone (PEEK) for the manufacturing of provisional abutments as an alternative to conventional titanium abutments has opened the restorative spectra, offering the clinician and the patient better aesthetics and adhesive outcomes than its predecessor. However, there is to date no clarity on the impact of PEEK on the bacterial growth and the specificity of the microbiota on the abutment surface. Therefore, the present study aims to determine the relative abundances of the different bacterial phyla and families in the microbiota present on the surface of PEEK and titanium implant-supported provisional abutments, as well as the effect of both materials on the presence of antibiotics resistance genes. Study Hypotheses: H1: The characteristics of the bacterial microbiota present at the connection area of implant-supported provisional abutments are dependent upon the abutment material. H2: An increased presence of antibiotic resistance genes is found in the bacterial microbiota on titanium provisional abutments when compared to that found on PEEK abutments. The study uses a metagenomic approach based on the characterization of the bacterial communities, as well as on the sequencing of the 16S gene, and on the other hand, on the sequencing of the high-throughput (HTS) of the whole genome, for variations of the antibiotic resistance genes. Sample retrieval will be conducted prior to implant placement, at the adjacent teeth gingival sulcus (t0), and two months after provisional abutment (and crown) connection (t1), from the retrieved abutments. Patient allocation in the PEEK or Titanium groups will be randomized. Intra- and interpatient comparisons will be conducted. Statistical analyses include two-way ANOVA and Tukey's post-hoc test, at p<0.05.

Official Title
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Bacterial Microbiota and Its Relation to Antimicrobial Resistance Genes in Implant-supported PEEK and Titanium Provisional Abutments

Conditions
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Peri-implant Mucositis, Oral Bacterial Infection, Bacterial Resistance

Intervention / Treatment
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* Device: Provisional abutment material


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: ASA I patients Indication of implant treatment to replace an upper or lower premolar Presence of natural teeth adjacent to the implant region Gingival biotype in the posterior region of 3 to 4 mm Exclusion Criteria: Immunosuppressed patients Tabacco, alcohol or drug addictions History of periodontal disease Need of bone grafting in the implant region
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: Basic Science
Allocation: Randomized
Intervention Model: Parallel Assignment
Interventional Model Description: Participants will be randomly assigned to one of two groups: PEEK or Titanium provisional-abutments. A sample of the niche microbiota will be retrieved prior to implant placement (t0) and two months after provisional abutment (crown) connection (t1).
Masking: Double


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: PEEK Provisional Abutment<br>The provisional crown will be fixed onto a PEEK abutment and then connected to the implant. The bis-acrylic resin used for the provisional crown will not invade the emergence profile of the abutment. | Device: Provisional abutment material<br>* The effect of the provisional abutment material on the characteristics of the bacterial microbiota will be assessed by using PEEK (experimental) or Titanium (active comparator) provisional abutments.<br>|
| Active Comparator: Titanium Provisional Abutment<br>The provisional crown will be fixed onto a titanium abutment and then connected to the implant. The bis-acrylic resin used for the provisional crown will not invade the emergence profile of the abutment. | Device: Provisional abutment material<br>* The effect of the provisional abutment material on the characteristics of the bacterial microbiota will be assessed by using PEEK (experimental) or Titanium (active comparator) provisional abutments.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Changes in the Number of Operational Taxonomic Units (OTUS) | Changes in the Number of Operational Taxonomic Units (OTUS) observed after the two months evaluation period will be assessed using UniFrac metrics. The weighted UniFrac distances will be used to perform a principal coordinate analysis (PCO). | Baseline (prior to abutment insertion) and two months after abutment insertion. | 
| Changes in Antibacterial Resistance Genes (ARG) | Changes in the ARG of the microbiota will be determined using the whole genome sequencing using the MiSeq Illumina method. | Baseline (prior to abutment insertion) and two months after abutment insertion. | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Changes in the number of bacterial species | Changes in the bacterial microbiota richness will be evaluated using a bias corrected Chao 1 richness estimator and the Shannon diversity index. | Baseline (prior to abutment insertion) and two months after abutment insertion. | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Implant-supported Provisional Abutment, Poly-ether-ether-ketone, Titanium, Bacterial Microbiota, Antimicrobial Resistance Genes