Subgingival Class V Composite With Moisture Control
A 45-year-old patient has a facial cervical lesion on tooth #6 with the gingival margin 1 mm subgingival. The lesion is active caries, and the patient reports drinking two sugary sodas daily. The gingival tissue is inflamed and bleeds on gentle probing. The dentist plans a composite restoration but is concerned about moisture control and bond durability. You have a rubber dam, clamps, floss ties, retraction cord, Teflon tape, a universal adhesive, a selective enamel-etch technique, and a flowable composite. The patient has a strong gag reflex and cannot tolerate a clamp on #6 for long. The adjacent #7 has a ceramic crown.
1. What isolation strategy would you recommend, and how would you sequence it to control gingival fluid and saliva without injuring the inflamed tissue?
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I would recommend a rubber dam if the patient can tolerate it, but because of the gag reflex and the subgingival margin, I would combine a floss-tied clamp on a posterior tooth with retraction cord and Teflon tape. I would place a thin retraction cord with aluminum chloride first to control gingival fluid, then isolate the field with Teflon tape and high-volume suction. I would avoid a clamp directly on #6 for long because the patient gags and the inflamed tissue may bleed. If a rubber dam is not feasible, I would use retraction cord plus Teflon and suction, and consider a dry-field isolator. The goal is a dry field without tissue injury; forcing a clamp or over-packing cord would increase bleeding and make the field worse.
2. Describe the bonding protocol you would use for this subgingival cervical lesion and explain why you would or would not etch dentin.
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For a subgingival cervical lesion, I would use selective enamel etching with 35–37% phosphoric acid for 15 seconds, rinse and dry, then apply a universal adhesive in two coats, air-thin, and light-cure. I would avoid prolonged etching of dentin because the dentin is already close to the gingiva and over-etching can deepen the lesion and increase sensitivity. I would place flowable composite in small increments, cure each, and verify the margin with an explorer and radiograph. If the margin cannot be isolated dry, I would not bond; I would stop and improve isolation. The reasoning is that bond durability depends more on a clean, dry substrate than on aggressive etching, especially when the margin is subgingival.