Stage III Periodontitis in a Smoker With Prediabetes Who Wants Implants
A 44-year-old woman attends for a check-up and asks about implants to replace her recently extracted lower right molars. Probing depths are 6–8 mm on the molars and 5 mm interproximally elsewhere, with generalised bleeding on probing and about 40% radiographic bone loss; teeth 46 and 47 have already been lost and 36 has grade II mobility. She smokes 12 cigarettes daily and was told last month that her HbA1c is 6.3% (prediabetes). BMI is 31 and blood pressure is 138/88 mmHg. She had 'deep cleaning' four years ago but has not attended since, her plaque score is high, and she brushes once daily without interdental cleaning. She takes no medication and has no allergies. She wants to know whether implants will work and whether she should have all her remaining teeth out.
1. Assign a periodontal diagnosis using the current classification and justify the stage and grade with the data given.
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Diagnosis: generalised periodontitis, Stage III, Grade C (with the caveat that grade should be confirmed with bone-loss/age data).
Why Stage III: interdental bone loss of roughly 40%, which extends into the middle third of the root and beyond the coronal third; probing depths of 6–8 mm; tooth loss attributable to periodontitis (46, 47); and grade II mobility on 36. Stage III is defined by bone loss extending to the middle third, probing depth ≥6 mm, and ≤4 teeth lost to periodontitis - this fits. Stage IV would additionally require ≥5 teeth lost, masticatory dysfunction, secondary occlusal trauma, or a bite collapse; none is described yet, though 36 with grade II mobility is a warning sign.
Why Grade C: she smokes ≥10 cigarettes per day, which is a recognised grade modifier toward C, and her glycaemic status (HbA1c 6.3%, prediabetes) is a further risk factor. The bone-loss/age ratio is about 0.9 (40 ÷ 44), which alone would suggest Grade B, so the smoking and metabolic modifiers tip the judgment to C. It is reasonable to say Grade B/C is borderline and to re-grade after risk-factor control.
Extent: generalised (≥30% of sites affected).
What this means clinically: she has a high risk of further progression, and both the stage and the grade change the treatment plan - more intensive therapy, closer maintenance intervals, and a frank discussion about the modifiable factors (smoking, plaque control, weight, glycaemia) before any implant is considered.
2. Set out the treatment sequence for the next 6 months and justify why antibiotics and immediate extraction of all remaining teeth are not the first steps.
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Phase 1 - risk factor control and behaviour change (weeks 0–4).
- Structured oral hygiene instruction: twice-daily brushing with correct technique, daily interdental brushes sized to the embrasures, and a fluoridated toothpaste.
- Smoking cessation: brief advice, referral to a cessation service, and a clear statement that smoking is the strongest modifiable driver of her bone loss and of implant failure.
- Glycaemia: refer to her physician for confirmation and management of prediabetes; explain that HbA1c control improves periodontal outcomes.
- Diet and weight discussion; confirm blood pressure follow-up.
Phase 1 - subgingival instrumentation (weeks 0–4). Full-mouth or quadrant-wise nonsurgical debridement with local anaesthesia as needed. Antibiotics are not routine: the evidence supports adjunctive systemic antibiotics only in selected cases after debridement, and misuse drives resistance; they cannot compensate for inadequate plaque control, and there is no acute infection described here.
Re-evaluation at 8–12 weeks. Repeat probing depths, bleeding scores, and plaque scores, and reassess 36's mobility and prognosis. Only now can residual pockets and the need for surgery be judged.
Phase 2 - if needed. Periodontal surgery for residual pockets ≥6 mm with bleeding, or extraction of teeth that are truly hopeless (36 may qualify if mobility and bone loss are advanced), with socket preservation if an implant is planned.
Phase 3 - replacement. Consider implants only once periodontal disease is stable, plaque control is reliable, and she has stopped smoking or at least reduced substantially.
Why not extract everything now: retaining teeth preserves bone and function and is usually preferable; total clearance is a last resort, and it would remove the very bone sites that could later support implants.
3. What would you tell her about implant survival in a patient with treated versus untreated periodontitis, and what conditions would you set before placing implants?
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Be honest that implants are not a cure for periodontal disease. Peri-implantitis is more common in patients with a history of periodontitis, and the risk is greatest when disease is active or plaque control is poor. Smoking and poor glycaemic control independently increase implant failure and peri-implant bone loss.
The key distinction: in a patient with treated, stable periodontitis and good maintenance, implant survival is reasonably good and broadly comparable to non-periodontal patients, though the risk of peri-implantitis remains elevated. In untreated or unstable periodontitis, placing implants into an inflamed mouth is associated with higher failure and peri-implantitis rates - the mouth is not a sterile field, and the same biofilm will colonise the implant surfaces.
Conditions I would set before placing implants:
- Completion of nonsurgical therapy and a documented stable re-evaluation (bleeding on probing reduced, no residual pockets ≥6 mm, plaque scores low).
- Reliable daily interdental cleaning demonstrated, not merely agreed to.
- Smoking cessation, or at minimum a substantial reduction, with clear documentation that smoking reduces survival.
- Glycaemic review with her physician; prediabetes is a risk factor rather than an absolute contraindication, but it must be managed.
- A commitment to supportive periodontal therapy every 3 months, with peri-implant probing and radiographs.
- A realistic discussion of alternatives - a removable partial denture or a fixed prosthesis - including their costs and biological costs to the remaining teeth.
Regarding full clearance: explain that it is not a shortcut to a healthy mouth, that it commits her to complex prosthetic reconstruction, and that her bone will resorb whether or not teeth are present. Offer a staged, evidence-based plan and record her decision.