PERI-EDU University Education
Inflammation around a dental implant can remain confined to the peri-implant mucosa or progress to destruction of the supporting bone. Distinguishing these conditions is essential because peri-implant mucositis can usually be controlled before structural support is lost, whereas peri-implantitis requires a more complex diagnostic and therapeutic pathway.
Educational focus: peri-implant health, peri-implant mucositis, peri-implantitis, biofilm-host interactions, inflammatory bone loss, clinical and radiographic assessment, and prevention.
Why does the distinction matter?
Peri-implant mucositis and peri-implantitis share an inflammatory origin but differ in their effect on the supporting tissues. Mucositis affects the soft-tissue compartment without continuing marginal bone loss beyond initial remodelling. Peri-implantitis combines mucosal inflammation with progressive loss of supporting bone. The transition is clinically important because control of mucositis contributes to prevention, while established peri-implantitis cannot be defined or managed on the basis of bleeding alone.
A patient may have no pain even when disease is present. Routine surveillance therefore depends on gentle probing, assessment of bleeding or suppuration, comparison of probing measurements over time and radiographic evaluation against an appropriate reference.
Three peri-implant conditions
| Condition | Soft-tissue findings | Bone-level interpretation | Clinical implication |
|---|---|---|---|
| Peri-implant health | No clinical signs of inflammation and no bleeding or suppuration on gentle probing. | No additional loss beyond changes related to initial remodelling. | Continue individualised supportive care and monitoring. |
| Peri-implant mucositis | Bleeding on gentle probing is the principal sign. Erythema, swelling, suppuration or increased probing depth caused by oedema may also occur. | No continuing marginal bone loss after initial healing. | Improve self-performed and professional biofilm control, correct local plaque-retentive factors and reassess. |
| Peri-implantitis | Inflammation with bleeding and/or suppuration, often accompanied by increasing probing depth or recession. | Progressive loss of supporting bone beyond initial remodelling. | Complete diagnostic assessment and sequential treatment are required. |
How does biofilm lead to tissue destruction?
Dental implants and their restorations provide non-shedding surfaces on which microbial biofilm can persist. Biofilm accumulation disturbs the balance between the resident microbiota and the host response. Neutrophils and macrophages are recruited to control the microbial challenge, while cytokines such as interleukin-1 beta, interleukin-6 and tumour necrosis factor alpha amplify the inflammatory response.
Persistent inflammation increases proteolytic activity, including matrix metalloproteinases, and alters regulation of bone turnover. A shift towards receptor activator of nuclear factor kappa-B ligand activity promotes osteoclast differentiation and bone resorption. Radiographic bone loss is therefore a late structural consequence of biological processes that begin at the biofilm-mucosa interface.
Why are peri-implant tissues vulnerable?
An implant lacks a periodontal ligament and cementum. The connective-tissue fibres adjacent to the implant do not insert into the titanium surface in the same way that periodontal fibres insert into a natural tooth. The vascular arrangement of the supracrestal tissues also differs. These anatomical characteristics do not cause peri-implantitis, but they influence how the tissues contain and respond to inflammation.
Patient responses vary considerably. Similar levels of plaque may produce limited inflammation in one patient and a more destructive response in another. A history of periodontitis, ineffective plaque control and absence of regular maintenance are established indicators of increased risk. Poorly controlled diabetes, smoking, prosthetic cleansability, implant position and other medical or local factors require individual interpretation.
Clinical assessment
1. Review the medical and dental history
Record previous periodontitis, smoking, diabetes control, medication exposure, changes in general health and adherence to supportive care. Risk factors modify interpretation but do not establish the diagnosis by themselves.
2. Examine the implant systematically
Use gentle probing at reproducible sites. Record probing depth, bleeding, suppuration, mucosal margin position, plaque, calculus and access for oral hygiene. A deep probing measurement alone does not diagnose peri-implantitis because healthy implants can have different soft-tissue dimensions.
3. Compare with baseline documentation
Baseline probing measurements and a radiograph obtained after completion of the prosthetic phase provide the strongest reference for detecting change. Use comparable projection geometry and stable implant landmarks whenever possible.
4. Interpret inflammation and bone change together
With baseline records, peri-implantitis is identified by inflammatory signs, increasing probing depth or recession, and progressive bone loss after initial healing. When previous records are unavailable, the 2018 case definition uses bleeding and/or suppuration, probing depth of at least 6 mm and a bone level at least 3 mm apical to the most coronal intra-osseous portion of the implant. These thresholds support classification in the absence of baseline data and should not replace clinical judgement.
Prevention begins before bone loss
Management of mucositis focuses on disruption of the biofilm, reinforcement of effective home care and professional plaque removal. The prosthesis should permit cleaning and clinical examination. Residual cement, excessive contour and other correctable plaque-retentive factors should be addressed where clinically feasible.
After treatment, peri-implant tissues require reassessment. The European Federation of Periodontology guideline recommends evaluating mucositis treatment outcomes after approximately two to three months. Long-term supportive peri-implant care should then follow an individual risk-based schedule. Persistent inflammation, increasing probing depth or radiographic change requires escalation of the diagnostic pathway.
Common interpretation errors
- Assuming that the absence of pain indicates peri-implant health.
- Diagnosing peri-implantitis from bleeding or probing depth without evaluating bone levels.
- Interpreting a single radiograph without considering projection and baseline measurements.
- Treating biomarkers as substitutes for clinical and radiographic assessment.
- Considering systemic risk factors as automatic contraindications instead of integrating them into individualised care.
Key learning points
- Peri-implant mucositis affects the mucosa without continuing marginal bone loss.
- Peri-implantitis includes inflammation and progressive loss of supporting bone.
- Biofilm initiates the lesion, while local conditions and host susceptibility modify its severity.
- Diagnosis depends on combined clinical, longitudinal and radiographic evidence.
- Early control of mucositis and structured supportive care form the main preventive pathway.
Download the full educational material
The extended PDF explains the biological progression from biofilm accumulation to osteoclast-mediated bone loss, provides a structured diagnostic pathway and summarises clinically relevant risk and prevention principles.
Download the full educational material (PDF)
Selected references
- Berglundh T, Armitage G, Araujo MG, et al. Peri-implant diseases and conditions: consensus report of workgroup 4 of the 2017 World Workshop. Journal of Clinical Periodontology. 2018;45(Suppl 20):S286-S291. doi:10.1111/jcpe.12957.
- Renvert S, Persson GR, Pirih FQ, Camargo PM. Peri-implant health, peri-implant mucositis, and peri-implantitis: case definitions and diagnostic considerations. Journal of Clinical Periodontology. 2018;45(Suppl 20):S278-S285. doi:10.1111/jcpe.12956.
- Heitz-Mayfield LJA, Salvi GE. Peri-implant mucositis. Journal of Clinical Periodontology. 2018;45(Suppl 20):S237-S245. doi:10.1111/jcpe.12953.
- Schwarz F, Derks J, Monje A, Wang HL. Peri-implantitis. Journal of Clinical Periodontology. 2018;45(Suppl 20):S246-S266. doi:10.1111/jcpe.12954.
- Herrera D, Berglundh T, Schwarz F, et al. Prevention and treatment of peri-implant diseases: the EFP S3 level clinical practice guideline. Journal of Clinical Periodontology. 2023;50(Suppl 26):4-76. doi:10.1111/jcpe.13823.
- Wang HL, et al. AO/AAP consensus on prevention and management of peri-implant diseases and conditions: summary report. Journal of Periodontology. 2025. doi:10.1002/JPER.25-0270.
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This educational material does not replace individual clinical assessment or specialist consultation.
This work was co-funded by the European Union under grant agreement No. 2024-1-PL01-KA220-HED-000251208. Views and opinions expressed are those of the author(s) only and do not necessarily reflect those of the European Union or the Foundation for the Development of the Education System (FRSE). Neither the European Union nor FRSE can be held responsible for them.