Peri-Implantitis: Implants in Periodontics Management

Dental implants can develop their own version of gum disease. Peri-implant mucositis is reversible inflammation of the gum around an implant, while peri-implantitis is the deeper disease where the supporting bone around the implant is progressively lost — the implant equivalent of periodontitis.

This matters because implants are a major investment, and peri-implantitis is the leading cause of late implant failure. Caught at the mucositis stage it is fully reversible; once bone loss starts, treatment becomes surgical and the implant's long-term survival is at stake.

Key Concepts

• Peri-implant mucositis: red, bleeding gum around an implant with no bone loss; reversible with cleaning.
• Peri-implantitis: bleeding plus deepening pockets plus radiographic bone loss around the implant; progressive without treatment.
• Osseointegration: the direct fusion of implant to bone that gives implants their strength; peri-implantitis destroys it.
• Diagnostic thresholds: bone loss of 3 mm or more below the implant shoulder (or 2 mm beyond initial remodelling), probing depth of 6 mm or more, and bleeding or pus on probing.
• Risk factors: history of periodontitis, poor plaque control, smoking, diabetes and excess cement left under the crown.
• CIST protocol: Cumulative Interceptive Supportive Therapy — a step-by-step scheme that escalates from cleaning to antiseptics to antibiotics to surgery as the disease worsens.

How It Works

Management follows the CIST escalation ladder:

1. Mechanical cleaning: plaque and tartar are removed with plastic or titanium instruments that cannot scratch the implant surface.
2. Antiseptic therapy: if bleeding persists, chlorhexidine rinses or local antiseptic gels are added.
3. Antibiotic therapy: for pockets of 5 mm or more with pus, local or systemic antibiotics target the remaining infection.
4. Surgical therapy: for bone loss with deep pockets, the gum is lifted, the implant surface is decontaminated (with air abrasion, lasers or chemicals), and the defect is grafted or the threads smoothed.
5. Explantation: if more than half the implant's bone support is lost and it is mobile, removal is the safe option.

Worked Example

A 60-year-old patient has a 5-year-old lower molar implant with bleeding gums:

1. Probing shows 7 mm pockets with pus, and the x-ray shows 4 mm of bone loss below the implant shoulder — this meets the peri-implantitis thresholds.
2. Non-surgical cleaning plus antiseptics are tried first for 6 weeks, but pockets remain 6 mm with bleeding.
3. Surgical treatment follows: the flap is raised, the implant surface is decontaminated, the defect is grafted with xenograft, and the crown's excess cement — the original trigger — is removed.
4. At one year, pockets measure 4 mm with no bleeding and the x-ray shows stable bone: the implant is saved, but only because treatment started before half the support was lost.

Common Misconceptions

• "Implants cannot get gum disease." They can, and because implants lack the ligament that protects natural teeth, the disease can progress faster around them.
• "A failing implant can always be re-grafted." Once bone loss passes about half the implant length, regeneration becomes unpredictable and removal is usually safer.

Real-World Applications

• Implant maintenance programmes: every implant patient is enrolled in lifelong 3 to 6 monthly recalls with annual x-rays.
• Treatment planning: patients with untreated periodontitis have their gum disease controlled before any implant is placed.
• Cement-retained crown checks: excess cement is a classic trigger, so screw-retained crowns are preferred where possible.
• Diabetic and smoking patients receive stricter maintenance because their peri-implantitis risk is higher.

Peri-implantitis is preventable, detectable and treatable — but only with vigilance. Regular probing, yearly x-rays and immediate action at the first sign of bleeding keep implants healthy for decades, while neglect turns a reversible inflammation into a lost implant.