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

Not Applicable

Recruiting

• Conditions: Peri-implantitis; Dental Plaque; Oral Biofilm
• Interventions: Device: Rings made of TAN (control); Device: Rings made of PA (test)

• Registration Number: NCT05122897
• Lead Sponsor: University Hospital, Basel, Switzerland

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.

Study Timeline

• Study First Submitted: 2021-11-03
• Study First Submitted QC: 2021-11-16
• Study First Posted: 2021-11-17
• Study Start: 2022-01-11
• Status Verified: 2024-12
• Last Update Submitted: 2024-12-12
• Last Update Posted: 2024-12-16
• Primary Completion: 2025-06
• Study Completion: 2025-06

Recruitment & Eligibility

• Status: RECRUITING
• Sex: All
• Target Recruitment: 33

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

Study & Design

• Study Type: INTERVENTIONAL
• Study Design: PARALLEL

Arm && Interventions

Group	Intervention	Description
Titanium-6Aluminum- 7Niobium alloy (TAN) control arm	Rings made of TAN (control)	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.
Pagalinor®2 (PA) test arm	Rings made of PA (test)	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.

Primary Outcome Measures

Name	Time	Method
Change in total bacterial load formed on the removable rings of each material	at 48 hours after ring placement, 2 weeks after ring placement and 3 months after ring placement	Quantification of the bacterial load formed on the removable rings of each material by quantitative real-time PCR (qPCR) using primers specific to highly conserved regions of bacterial 16S rRNA genes.

Secondary Outcome Measures

Name	Time	Method
Change in probing pocket depth (PPD) in mm	at baseline, 2 weeks after ring placement and 10 weeks after ring placement	Change in probing pocket depth (PPD) to investigate the inflammatory tissue response
Change in bleeding on probing (BoP)	at baseline, 2 weeks after ring placement and 10 weeks after ring placement	Recording bleeding on probing (BoP) to investigate the inflammatory tissue response
Change in bacterial composition (taxonomic diversity) between different materials at various time points by using metagenomic sequencing analysis	at baseline, 2 weeks after ring placement and 10 weeks after ring placement	To assess differences in bacterial composition (taxonomic diversity) between different materials at various time points by Illumina MiSeq sequencing. The taxonomy of each 16S rRNA gene sequence will be analyzed by Ribosomal Database Project (RDP) Classifier (http://rdp.cme.msu.edu/) against the SILVA (SSU123) 16S rRNA database using a confidence threshold of 70%.
Change in noninvasive laser doppler flowmetry	at baseline, 2 weeks after ring placement and 10 weeks after ring placement	Change in noninvasive laser doppler flowmetry to to measure the blood flow of mucosa next to the ring

Trial Locations

Locations (1)

UZB (University Center for Dental Medicine Basel); 🇨🇭 Basel, Switzerland