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

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.

• Change in bacterial composition (taxonomic diversity) between different materials at various time points by using metagenomic sequencing analysis [Срок оценки: at baseline, 2 weeks after ring placement and 10 weeks after ring placement]
• Change in probing pocket depth (PPD) in mm [Срок оценки: at baseline, 2 weeks after ring placement and 10 weeks after ring placement]
• Change in bleeding on probing (BoP) [Срок оценки: at baseline, 2 weeks after ring placement and 10 weeks after ring placement]
• Change in noninvasive laser doppler flowmetry [Срок оценки: at baseline, 2 weeks after ring placement and 10 weeks after ring placement]
• Change in the cells of the peri-implant soft tissue [Срок оценки: at 2 weeks after ring placement]