- Oral Microbiome Library
- Implants
- P. aeruginosa
Pseudomonas aeruginosa
Also called the outsider
- Evidence
- Limited evidenceLimited · Found at failing implants in small studies
- Class
- Bacterium · Dental implant · panel code Pa
- Sources
- 4 peer-reviewed sources
Key takeaway
P. aeruginosa is not a normal mouth resident; it is a hospital-and-environment opportunist that resists many antibiotics. It has been recovered from failing dental implants and peri-implantitis sites in several small studies, which is why it sits on the panel as an implant-health marker [1][2].
| What it is | A Gram-negative, biofilm-forming environmental bacterium. |
|---|---|
| Where it lives | Water, soil and hospitals; in the mouth, occasionally around implants, dentures or in people with weakened immunity. |
| Role in the mouth | An uninvited guest that can colonise the tissue around implants [3]. |
| Beyond the mouth | A major cause of hospital-acquired and cystic-fibrosis lung infections. |
| Evidence strength | Limited evidence. Mostly case reports, small samples or lab and animal work. |
| How we measure it | Quantitative PCR (qPCR) on your saliva sample, reported as genomic copies per mL against a reference range. Ranges are for context, not diagnostic cut-offs. |
What is Pseudomonas aeruginosa?
P. aeruginosa is one of medicine’s most troublesome opportunists, famous for antibiotic resistance and for building biofilms on catheters and in the lungs of people with cystic fibrosis. It is not part of healthy oral flora.
Peri-implant diseases, inflammation of the gum around an implant (mucositis) and bone loss around it (peri-implantitis), were formally defined in the 2017 World Workshop classification [4]. Several microbiological studies of those sites have turned up P. aeruginosa among the usual periodontal suspects.
How does P. aeruginosa work?
It excels at surfaces. Titanium implants lack the periodontal ligament that helps natural teeth resist infection, and once a biofilm forms on the implant surface it is difficult to remove. P. aeruginosa forms dense, protective biofilms and tolerates many antimicrobials, which makes it a particularly unwelcome colonist [3].
What does the research show?
A 1999 study of failing implants found opportunistic organisms including P. aeruginosa and enteric rods at a share of sites, alongside periodontal pathogens [1]. A 2015 study likewise detected P. aeruginosa in a minority of peri-implantitis patients [2].
A 2017 systematic review concluded that peri-implantitis is a mixed infection, dominated by periodontal species but with opportunists such as P. aeruginosa and Staphylococcus aureus appearing in some patients [3]. The evidence base is small studies, hence our limited grade.
What does a result mean?
A detected level is a reason to have the tissue around any implant examined; it does not diagnose peri-implantitis, which is assessed by probing, bleeding and X-rays [4].
If you have no implants, a low-level detection is most often transient, from water or environment, and your dentist will read it in context.
Frequently asked questions
I don’t have implants. Why is this on my panel?
The panel is fixed for everyone. Without implants, a detection is usually incidental and transient, though your dentist may still ask about dentures or recent illness.
Does P. aeruginosa cause implant failure?
It has been found at failing implants, but peri-implantitis is a mixed infection led by periodontal bacteria. Its exact contribution is not established [3].
Is it antibiotic resistant?
Often. That is a feature of the species generally, and one reason prevention around implants is emphasised over treatment [3].
Sources
- Leonhardt A, Renvert S, Dahlén G. Microbial findings at failing implants. Clin Oral Implants Res 1999. DOI: 10.1034/j.1600-0501.1999.100501.xPMID 10551058
- Albertini M, López-Cerero L, O'Sullivan MG, et al.. Assessment of periodontal and opportunistic flora in patients with peri-implantitis. Clin Oral Implants Res 2015. DOI: 10.1111/clr.12387PMID 24720498
- Lafaurie GI, Sabogal MA, Castillo DM, et al.. Microbiome and Microbial Biofilm Profiles of Peri-Implantitis: A Systematic Review. J Periodontol 2017. DOI: 10.1902/jop.2017.170123PMID 28625077
- Berglundh T, Armitage G, Araujo MG, et al.. Peri-implant diseases and conditions: Consensus report of workgroup 4 of the 2017 World Workshop on the Classification of Periodontal and Peri-Implant Diseases and Conditions. J Clin Periodontol 2018. DOI: 10.1111/jcpe.12957PMID 29926491
This page is educational and does not constitute medical or dental advice, a diagnosis, or a health claim. The OneOral Bio Test reports the organisms and measurements present in a saliva sample; reference ranges are for context only and are not diagnostic thresholds. A licensed dentist reviews results in the context of your examination and history. Content reviewed by the OneOral Clinical Team; research summaries reflect the cited sources as of Oct 27, 2026.