Periodontal Management Before Crown Lengthening for a Fractured Molar
A 45-year-old woman presents with a fractured distolingual cusp on tooth 46. The fracture extends 1 mm below the gingival margin. Probing depths are 4-5 mm on the distal and lingual, with bleeding on probing but no suppuration. Radiographs show 30% horizontal bone loss and adequate bone support; the fracture line is 2 mm coronal to the alveolar crest. She smokes 10 cigarettes per day and has not had periodontal therapy in 3 years. She wants the tooth restored and asks whether she needs gum surgery first.
1. Does this patient need crown lengthening, and what is your rationale?
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Assessment: The fracture is 1 mm subgingival, and the biologic width (junctional epithelium plus connective tissue attachment, roughly 2 mm) must be respected for a stable restoration margin. With 30% bone loss and the fracture 2 mm coronal to the crest, there may be enough room to place a margin without violating biologic width, but the subgingival extent and the 4-5 mm pockets complicate isolation and margin capture.
Options:
- Orthodontic extrusion to move the fracture margin supragingivally, preserving bone and esthetics; slower but avoids surgery.
- Surgical crown lengthening if the margin would otherwise encroach on biologic width; requires removing bone, which may compromise the adjacent tooth and esthetics.
- Restoration with a deep margin elevation if isolation can be achieved and the margin is not violating biologic width.
Rationale: Crown lengthening is indicated when a stable margin cannot be placed without impinging on the attachment apparatus. Given the fracture is only 1 mm subgingival and there is 2 mm of bone-to-fracture distance, a conservative approach with isolation and possibly minor gingivectomy may suffice. However, active periodontal disease and smoking must be addressed first; proceeding with crown lengthening in an inflamed, smoking patient increases the risk of poor healing and recurrence.
2. How do smoking and untreated periodontitis change your sequencing and prognosis?
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Smoking: Smoking impairs neutrophil function, reduces gingival blood flow, and blunts healing. It is a major risk factor for periodontal progression and for failure of regenerative and surgical procedures. Smoking cessation counseling should be provided, and the patient should be informed that surgical outcomes are less predictable while she continues to smoke.
Untreated periodontitis: The 4-5 mm pockets with bleeding indicate active inflammation. Surgery in an inflamed field risks infection and poor flap adaptation. The standard sequence is:
- Oral hygiene instruction and smoking cessation counseling.
- Non-surgical periodontal therapy (scaling and root planing) with re-evaluation in 6-8 weeks.
- Reassess pocket depths, bleeding, and plaque control.
- Proceed with crown lengthening or extrusion only after inflammation is controlled and the patient demonstrates adequate plaque control.
Prognosis: With disease control and smoking cessation, the tooth has a fair-to-good prognosis. If she continues smoking and inflammation persists, the risk of recurrent caries, periodontal breakdown, and eventual loss increases. Document the counseling and the staged plan.