Two missing molars, a DOAC and a night-time clencher
Mr D, 61, is seen in a treatment-planning station. Teeth 46 and 47 were lost four and six years ago respectively. Tooth 45 is present with a large amalgam and a fractured distolingual cusp; it is asymptomatic and responds normally to cold testing. Tooth 48 is mesioangularly impacted and partly erupted with a 5 mm pocket on its distal aspect. He wears an upper cobalt-chromium partial denture and reports night-time clenching; there are wear facets on the anterior teeth, bilateral buccal exostoses and palpable masseter hypertrophy. Medical history: atrial fibrillation on apixaban 5 mg twice daily, BMI 31, HbA1c 6.6%, and he smokes 20 cigarettes a day. A cone-beam CT shows a ridge width of 5 mm and 12–13 mm of bone above the inferior alveolar canal at both 46 and 47. He wants a fixed replacement and asks whether he will have to stop the blood thinner.
1. Set out the realistic options for replacing 46 and 47 and recommend one, with your reasoning.
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Options:
- Two implants with individual crowns at 46 and 47. This is the closest thing to replacing the missing teeth without involving 45. The constraint is ridge width: 5 mm is marginal for a molar implant (typically 5.0 mm diameter, requiring roughly 6–7 mm of buccolingual bone with a 2 mm safety margin on the lingual and 1.5–2 mm buccal). Expect simultaneous or staged guided bone regeneration, or a decision to place a narrower platform accepting higher fracture risk.
- Implant at 46 only, leaving 47 unrestored (shortened dental arch). Defensible if 47 space is limited and 46 restores the masticatory unit; but 48 is impacted and partially erupted with a 5 mm distal pocket, so the posterior region is not problem-free.
- Removable partial denture. Least invasive, but he already wears an upper partial, dislikes the idea, and the molars would be clasped to 45 and 48 - a poor design.
- Bridgework. There is no distal abutment, so a conventional fixed bridge is not possible without involving 48. Uprighting 48 surgically/orthodontically to use as an abutment is theoretically possible but has a poor predictability and commits a compromised tooth.
Recommendation: two implants, contingent on GBR for width, with 48 extracted or at least reviewed to eliminate the periodontal pocket and improve access. Sequence: oral hygiene and smoking cessation discussion → 45 restoration → 48 decision → implant placement with GBR → healing → crowns. Warn that 45 will also need full coverage given the fractured cusp.
2. How do you answer his question about stopping apixaban, and what local measures will you plan?
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Answer: no, he should not stop it - and I will not advise him to. Apixaban is a direct oral anticoagulant with a half-life of about 12 hours taken twice daily. Its purpose is stroke prevention in atrial fibrillation; interrupting it without a medical reason creates a serious thromboembolic risk, and the bleeding risk of routine implant placement or extraction does not justify that.
Practical management:
- Do not organise an INR - it is not a valid test for apixaban and will give falsely reassuring results.
- Confirm with his physician that renal function is acceptable and that nothing has changed; document the conversation.
- Consider timing the appointment roughly 12 or more hours after the last dose so that peak effect has passed. Omitting a single dose for higher-bleeding-risk procedures is a decision for the prescriber, not for me, and is not routinely necessary for simple implant placement.
- Surgical technique: minimally traumatic, flapless where possible, primary closure with sutures, no lingual perforation, avoid excessive palatal/lingual flap reflection.
- Local haemostatic measures: pressure pack, sutures, oxidised cellulose or gelatin sponge in the socket, and 4.8% tranexamic acid mouthwash 10 mL four times daily for two days.
- Written postoperative instructions, an out-of-hours contact, and clear advice to attend emergency services if bleeding cannot be controlled by 20 minutes of firm pressure.
Every step is documented, including that the anticoagulant was continued on medical advice.
3. How do his smoking and his bruxism change your plan and your consent discussion?
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Smoking (20/day): this is a material risk factor, not a moral issue. It is associated with a substantially higher implant failure rate, more postoperative infection, poorer bone healing and a higher long-term risk of peri-implantitis and marginal bone loss. I would give brief, non-judgemental cessation advice, offer referral to a cessation service, and explain that stopping for a period around surgery (ideally several weeks before and after) measurably improves outcomes. If he declines, implants are still possible with informed consent - but he must know the reduced predictability, and the alternative of a removable prosthesis must be presented fairly, not as a threat. Record that this was discussed.
Bruxism: wear facets, exostoses, masseter hypertrophy and self-reported clenching indicate a real risk of ceramic chipping, screw loosening, abutment fracture and overload. Modifications:
- Prescribe a hard occlusal splint for night wear before and after treatment.
- Use screw-retained restorations where possible for retrievability.
- Choose an implant diameter and restorative material that tolerate load rather than under-sizing; consider splinting the two adjacent implants rather than leaving them as independent units, though the evidence is not decisive.
- Avoid cantilevers and check the occlusal scheme in lateral excursions.
- Review occlusion and the splint at each maintenance visit.
Overall consent must include the possibility of GBR, the chance of an implant failing and needing replacement, the costs of each stage, and the maintenance commitment.