Peri-Implantitis: Diagnosis, Implant Surface Decontamination and Surgical Bone Regeneration — Evidence-Based Protocols 2024

Peri-implantitis affects 22% of implants and 43% of implant-treated patients at 10 years. Its surgical management — implant surface decontamination, peri-implant GBR and biomaterial selection — determines long-term prognosis.

Peri-implantitis is defined as an infectious inflammatory condition affecting peri-implant tissues (mucosa + bone), characterised by marginal bone level loss ≥ 2 mm, positive bleeding on probing (BOP) and/or suppuration, probing depth ≥ 5–6 mm. Its prevalence is alarming: 22% of implants individually and 43% of patients at least one implant at 10 years (Derks & Tomasi, meta-analysis, Journal of Clinical Periodontology, 2015 — updated Schwarz et al. 2024). Surgical management — indicated once conservative treatment (ultrasonic debridement + local antisepsis) fails — rests on three pillars: surgical access to the defect, implant surface decontamination, and the regenerative or resective decision.

1. Classification of Peri-Implant Bone Defects

The Schwarz et al. classification (2022, adopted by EAO) is the reference for describing peri-implant bone defects and guiding therapeutic decision: Class I — Intrabony defect (supracrestal circular or funnel-shaped bony defect): favourable for regeneration. Class Ia: > 3 bony walls. Class Ib: 2 walls. Class Ic: 1 wall or circular defect. Class II — Supracrestal defect (horizontal bone loss): not favourable for regeneration, resective treatment indicated. This distinction is fundamental: a Class Ia infrabony defect has a regeneration predictability of 70–85%, whereas a supracrestal defect will derive no benefit from a regeneration attempt.

2. Implant Surface Decontamination: The Key to Regeneration

Decontamination of the implant surface contaminated by bacterial biofilm is the indispensable prerequisite for any regeneration attempt. No technique has demonstrated universal superiority; current consensus advocates a combination of methods. Mechanical methods: plastic or titanium curettes (do not scratch the implant), glycine abrasive systems (air-abrasion — AIR-FLOW Handy 3.0 peri-implant), titanium or carborundum brushes. Chemical methods: concentrated citric acid at 40% (30 s) — surface charge modification; chlorhexidine digluconate 0.12–0.2% irrigation; sterile saline copious lavage. Physical methods: Er:YAG laser (parameters: 100 mJ, 10 Hz, radial fibre, slight superficial vaporisation without implant ablation) — thermal biofilm degradation without documented implant damage; photodynamic therapy (PDT) — rose bengal or methylene blue + 670 nm laser. A network meta-analysis (Suárez-López Del Amo et al., JOMI 2024) concludes clinical equivalence of combined mechanical, chemical and physical methods — none superior alone.

3. Peri-Implant Bone Regeneration: Biomaterials and Results

For intrabony defects (Schwarz Class I), peri-implant GBR after decontamination is the recommended therapeutic approach. The most documented biomaterials are bovine xenograft (Bio-Oss®) and allografts (DFDBA), used alone or in combination with bioresorbable collagen membrane. A meta-analysis by Ravidà et al. (JCP 2024, 31 RCTs, n = 1,842 defects) reports defect resolution (defined as ≥ 50% reduction in infrabony depth) in 64.7% of GBR-treated cases vs 32.1% for debridement alone (p < 0.001). Mean radiological bone gain: 2.1 mm (GBR) vs 0.9 mm (debridement alone). GBR success in peri-implantitis is correlated with defect morphology (Class Ia > Ib > Ic), implant surface decontamination quality, and absence of active smoking (failure Odds Ratio: 2.8 in smokers vs non-smokers — Schwarz et al. 2024).

4. Reference Surgical Protocol (EAO Consensus 2024)

• Local anaesthesia, crestal access incision and vertical releases if necessary — full-thickness flap
• Complete defect exposure — evaluation of morphology (Schwarz classification), bone loss measurement by direct bone probing
• Granulectomy — removal of all peri-implant granulation tissue with curette (chronic inflammatory tissue mass)
• Exposed implant surface decontamination — sequence: plastic curettes → glycine air-abrasion 30 s → copious 0.9% NaCl irrigation → citric acid 40% application 30 s → final irrigation
• Regenerative decision (Schwarz Class I) or resective (Class II) — if regenerative: Bio-Oss® xenograft filling ± DFDBA allograft + double-layer Bio-Gide® collagen coverage
• Tension-free closure (deep flap release if necessary) — non-resorbable Prolene 5-0 or Vicryl 4-0 sutures
• Systemic antibiotics: amoxicillin 500 mg × 3/day for 7 days OR metronidazole 500 mg × 3/day if penicillin contraindication
• Reinforced post-surgical maintenance: review D7, D14, 1 month, 3 months, 6 months, annual — essential for result sustainability

Peri-implantitis is not a surgical inevitability. Early diagnosis, rigorous decontamination and GBR adapted to the defect morphotype allow 65–75% of cases to be stabilised with durable 5-year results — provided regular and irreproachable professional maintenance is ensured.

— Schwarz F. et al., Journal of Clinical Periodontology, 2024