Investigation of Biofilm Formation on Temporary push-on Rings of Implant Crowns

NCT ID: NCT05122897

Last Updated: 2025-07-25

Basic Information

• Recruitment Status: RECRUITING
• Clinical Phase: NA
• Total Enrollment: 33 participants
• Study Classification: INTERVENTIONAL
• Study Start Date: 2022-01-11
• Study Completion Date: 2026-02-28

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.

Conditions

Dental Plaque; Oral Biofilm; Peri-implantitis

Study Design

• Allocation Method: RANDOMIZED
• Intervention Model: PARALLEL
• Primary Study Purpose: DIAGNOSTIC
• Blinding Strategy: DOUBLE

Study Groups

Pagalinor®2 (PA) test arm

All patients 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.

Group Type: EXPERIMENTAL

Rings made of PA (test)

Intervention Type: DEVICE

Rings made of PA (test) 0.2mm in thickness are pushed on the conical titanium base (abutment) of implant crowns and are removed and replaced after 48h, 2 weeks and 3 months for quantification of the bacterial biofilm. Test rings are applied in a split-mouth design provided that 2 implants are present (total of 4 months study period), or one after the other when only 1 implant is present (total of 8 months study period).

Titanium-6Aluminum- 7Niobium alloy (TAN) control arm

All patients 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.

Group Type: ACTIVE_COMPARATOR

Rings made of TAN (control)

Intervention Type: DEVICE

Rings made of TAN (control) 0.2mm in thickness are pushed on the conical titanium base (abutment) of implant crowns and are removed and replaced after 48h, 2 weeks and 3 months for quantification of the bacterial biofilm. Control rings are applied in a split-mouth design provided that 2 implants are present (total of 4 months study period), or one after the other when only 1 implant is present (total of 8 months study period).

Interventions

Rings made of PA (test)

Rings made of PA (test) 0.2mm in thickness are pushed on the conical titanium base (abutment) of implant crowns and are removed and replaced after 48h, 2 weeks and 3 months for quantification of the bacterial biofilm. Test rings are applied in a split-mouth design provided that 2 implants are present (total of 4 months study period), or one after the other when only 1 implant is present (total of 8 months study period).

Intervention Type: DEVICE

Rings made of TAN (control)

Rings made of TAN (control) 0.2mm in thickness are pushed on the conical titanium base (abutment) of implant crowns and are removed and replaced after 48h, 2 weeks and 3 months for quantification of the bacterial biofilm. Control rings are applied in a split-mouth design provided that 2 implants are present (total of 4 months study period), or one after the other when only 1 implant is present (total of 8 months study period).

Intervention Type: DEVICE

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

• Minimum Eligible Age: 18 Years
• Eligible Sex: ALL
• Accepts Healthy Volunteers: Yes

Sponsors

ITI International Team for Implantology, Switzerland

OTHER

Sponsor Role: collaborator

University Hospital, Basel, Switzerland

OTHER

Sponsor Role: lead

Responsible Party

Responsibility Role: SPONSOR

Principal Investigators

Nicola U. Zitzmann, Prof. Dr.

Role: PRINCIPAL_INVESTIGATOR

University Center for Dental Medicine Basel

Locations

UZB (University Center for Dental Medicine Basel)

Basel, , Switzerland

Site Status: RECRUITING

Countries

Switzerland

Central Contacts

Nicola U. Zitzmann, Prof. Dr.

Role: CONTACT

n.zitzmann@unibas.ch

+41 61 267 26 36

Lucia K. Zaugg, Dr. med. dent.

Role: CONTACT

lucia.zaugg@unibas.ch

+41 61 267 26 36

Facility Contacts

Nicola U. Zitzmann, Prof. Dr.

Role: primary

n.zitzmann@unibas.ch

+41 61 267 26 36

Lucia K. Zaugg, Dr. med. dent.

Role: backup

lucia.zaugg@unibas.ch

+41 61 267 26 36

Other Identifiers

2021-D0061; ex21Zitzmann

Identifier Type: -

Identifier Source: org_study_id