Clinical trial NCT05122897: Investigation of Biofilm Formation on Temporary push-on Rings of Implant Crowns
Official title: Temporary push-on Rings of Antimicrobial Alloys for Transmucosal Implant Abutment Systems: a Randomized Clinical Study on Early and Mature Biofilm Formation
Study type: INTERVENTIONAL
Overall status: RECRUITING
Phase: NA
Conditions: Dental Plaque
Oral Biofilm
Peri-implantitis
Keywords: Titanium-6Aluminum-7Niobium alloy
Pagalinor
transmucosal implant abutment
implant crowns
temporary push-on rings
Variobase abutments
Lead sponsor: University Hospital, Basel, Switzerland
Sponsor class: OTHER
Collaborators: name: ITI International Team for Implantology, Switzerland
First posted: 2021-11-17
Enrollment: 33
Sex: ALL
Minimum age (years): 18
Standard ages: ADULT
OLDER_ADULT
Accepts healthy volunteers: yes
Allocation: RANDOMIZED
Intervention model: PARALLEL
Intervention model description: All patients enrolled in the current investigation will wear both the test and control ring material for a within-subject comparison. Ideally, biofilm sampling can be performed in a split mouth design (randomly allocated materials within subjects) with one patient having two implants for placing the test and the control material at the same time. In addition, patients providing one implant, will receive test and control push-on rings in a randomly assigned order, so that both materials are assessed in a consecutive manner.
Primary purpose: DIAGNOSTIC

Brief summary: This in-vivo study investigates early (48h), mature (2 weeks) and long-term (3 months) biofilm formation and composition on temporary push-on cones (exchangeable conical rings) made of noble-alloy-based materials (Pagalinor, PA) in comparison to Titanium-6Aluminum-7Niobium alloy (TAN) presently used in the transmucosal portion of dental implant abutments.

Detailed description: Oral biofilm (dental plaque) consists of bacteria and their metabolic products as well as saliva components and food residues. It is recognizable as a tough and structured coating on teeth and artificial surfaces within the oral cavity. Plaque development is a physiological process that begins immediately after cleaning of the oral surface. If the biofilm is not removed by daily oral hygiene, it continues to mature while changing the structure and its microbial composition.

Implant restorations comprise the osseous implant portion predominantly manufactured from titanium alloys, the transmucosal implant portion (in most implant systems as a separate abutment), and the clinical crown, which is in most systems extraorally cemented on an abutment and screw-retained onto the implant. According to current knowledge, microbial colonization of the implant abutment surface plays a significant role in the aetiology of peri-implantitis.

This study investigates the antibacterial potential of a temporary push-on cone (conical ring) that could reduce the risk of bacterial related peri-implant diseases due to decreased biofilm susceptibility, compared to current available transmucosal materials, in the short- and long-run. The test material Pagalinor®2 (PA) is an established material in dental medicine and has proven to accumulate least biofilm in an in-vivo biofilm sampling model using removable splints. The control material consists of the current transmucosal implant abutment material Titanium-6Aluminum- 7Niobium alloy (TAN). The push-on rings are designed for repeated application along the transmucosal implant abutment portion with high precision fit and will allow biofilm sampling in the natural implant environment. Profound insight into the native homeostasis of biofilm formation will be obtained and therefore enhance the knowledge about long-term tissue response.

Eligibility criteria: Inclusion Criteria:

* Informed Consent signed by the subject
* Presence of one or more bone level titanium implant prior to insertion of the final restoration
* No systemic illness
* No heavy smoking (smoking \<10 cigarettes/day)
* No pregnancy
* No active periodontitis (probing pocket depth ≤4 mm)
* No pharmacological treatment or antibiotic therapy during or up to three months before the study

Exclusion Criteria:

* Systemic illness (e.g. Diabetes)
* Heavy smoking (smoking \>10 cigarettes/day)
* Known or suspected non-compliance, drug or alcohol abuse
* Pregnancy
* Active periodontitis (probing pocket depth \>4 mm)
* Pharmacological treatment or antibiotic therapy during or up to three months before the study

Primary outcomes:
measure: Change in total bacterial load formed on the removable rings of each material
timeFrame: at 48 hours after ring placement, 2 weeks after ring placement and 3 months after ring placement
Secondary outcomes:
measure: Change in bacterial composition (taxonomic diversity) between different materials at various time points by using metagenomic sequencing analysis
timeFrame: at baseline, 2 weeks after ring placement and 10 weeks after ring placement
measure: Change in probing pocket depth (PPD) in mm
timeFrame: at baseline, 2 weeks after ring placement and 10 weeks after ring placement
measure: Change in bleeding on probing (BoP)
timeFrame: at baseline, 2 weeks after ring placement and 10 weeks after ring placement
measure: Change in noninvasive laser doppler flowmetry
timeFrame: at baseline, 2 weeks after ring placement and 10 weeks after ring placement
Other outcomes:
Locations:
city: Basel
country: Switzerland
facility: UZB (University Center for Dental Medicine Basel)
Study officials:
affiliation: University Center for Dental Medicine Basel
name: Nicola U. Zitzmann, Prof. Dr.
role: PRINCIPAL_INVESTIGATOR
References: