Peri-Implant Diseases and Conditions

Quick reference for the entities and case definitions from the 2017 World Workshop classification. Summarized from 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.

Baseline first

There is no generic implant and no single “healthy” probing depth. Obtain baseline radiographic and probing measurements after the implant-supported prosthesis is completed (plus a post-loading radiograph) so future changes can be judged against initial physiological remodeling.

Entities at a glance

  • Peri-implant health — Absence of erythema, bleeding on probing (BoP), swelling, and suppuration. No defined “healthy” probing depth range; clinical signs of inflammation matter more. Can exist around implants with reduced bone support.
  • Peri-implant mucositis — Reversible, plaque-induced inflammation of the soft tissue only. Defining sign is BoP on gentle probing; erythema, swelling, and/or suppuration may also be present. Probing depth may increase from swelling or reduced probing resistance. No bone loss beyond initial remodeling. Plaque is the established etiology; can resolve with biofilm control (may take >3 weeks).
  • Peri-implantitis — Plaque-associated pathological condition with mucosal inflammation plus progressive loss of supporting bone. Signs: BoP and/or suppuration, increased probing depth and/or mucosal recession, and radiographic bone loss vs. baseline. Probing depth correlates with bone loss (severity indicator); progression is non-linear/accelerating and often faster than periodontitis.
  • Hard- and soft-tissue deficiencies — Non-inflammatory ridge/mucosa deficits. Hard-tissue: diminished alveolar ridge dimensions after tooth loss (worsened by lost periodontal support, endodontic infection, root fractures, thin buccal plate, trauma, sinus pneumatization, agenesis, etc.). Soft-tissue: peri-implant mucosal recession driven by implant malpositioning, lack of buccal bone, thin tissue, lack of keratinized mucosa, and surgical trauma. Keratinized mucosa benefit is equivocal but may aid comfort and plaque removal.

Summary table

EntityDefinitionKey clinical signsBoP / probingBone loss
Peri-implant healthHealthy peri-implant tissues; can exist with reduced bone supportNo erythema, swelling, or suppurationBoP absent; no probing-depth increase vs. baselineNone beyond initial crestal remodeling
Peri-implant mucositisReversible plaque-induced inflammation of soft tissue onlyErythema, swelling, ± suppurationBoP present on gentle probing; ± increased probing depthNone beyond initial crestal remodeling
Peri-implantitisPlaque-associated inflammation + progressive bone lossInflammation, ± suppuration, ± mucosal recessionBoP and/or suppuration present; increased probing depthProgressive radiographic bone loss beyond remodeling
Hard-tissue deficiencyReduced alveolar ridge dimensions (non-inflammatory)Ridge volume / contour deficitN/A (not inflammatory)Pre-existing ridge resorption, not active disease
Soft-tissue deficiencyPeri-implant mucosal recession / inadequate keratinized tissueRecession, thin/insufficient mucosaN/A (not inflammatory)N/A

Case definitions (day-to-day practice)

  • Health — Absence of inflammation; absence of BoP/suppuration on gentle probing; no probing-depth increase vs. previous exams; no bone loss beyond initial remodeling.
  • Mucositis — BoP and/or suppuration on gentle probing (± increased probing depth); no bone loss beyond initial remodeling.
  • Peri-implantitis — BoP and/or suppuration; increased probing depth vs. previous exams; bone loss beyond initial remodeling.
    • Without baseline records: BoP and/or suppuration + probing depth ≥6 mm + bone level ≥3 mm apical to the most coronal intraosseous portion of the implant.

Key clinical takeaways

  • Probe peri-implant tissues with a light force at every recall — it is the primary way to detect BoP and track probing-depth/margin change.
  • Mucositis is the assumed precursor to peri-implantitis; regular maintenance is protective.
  • Major peri-implantitis risk indicators: history of severe periodontitis, poor plaque control, and no maintenance after implant therapy. Smoking/diabetes data are inconclusive; residual submucosal cement and hygiene-unfriendly implant positioning are limited-evidence factors.