Implant Placement in a Smoker with Limited Bone
A 52-year-old man requests a single implant to replace tooth 14, extracted 6 months ago. He smokes 15 cigarettes per day and has done so for 25 years. Cone-beam CT shows a ridge width of 4.5 mm and height of 9 mm above the inferior alveolar canal; the planned implant is 4.0 mm diameter and 8 mm length. The opposing tooth 44 is restored and in occlusion. His plaque score is 25%, and he has no history of periodontitis. He declines smoking cessation but is willing to 'cut down.' He wants the implant placed at the same visit as the consultation if possible.
1. What are the key risk factors for implant failure here, and how do they affect your decision to place the implant now?
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The dominant risk is smoking: 15 cigarettes/day is a moderate-to-heavy exposure associated with increased implant failure, peri-implantitis, and marginal bone loss, and it impairs healing. The ridge width of 4.5 mm for a 4.0 mm implant leaves only about 0.25 mm of buccal and lingual bone if centered, which is inadequate for predictable long-term stability and increases the risk of dehiscence and mucosal recession. The 9 mm height above the canal limits implant length to 8 mm, which is acceptable but reduces the margin for error. Plaque score of 25% is borderline and adds risk. Placing the implant immediately at the consultation would ignore the need to address hygiene, discuss smoking, and plan for possible ridge augmentation. My judgment: do not place at the consultation. Address plaque control, document smoking counseling, and consider whether the ridge needs augmentation or a narrower implant; the combination of smoking and thin ridge makes this a higher-risk case that warrants staged planning.
2. How would you sequence treatment and what would you tell the patient about smoking and expected outcomes?
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Sequence: (1) hygiene phase with plaque score reduction and interdental instruction; (2) smoking counseling with documented advice to quit, acknowledging his willingness to cut down is a partial step; (3) re-evaluate ridge dimensions and consider whether a 3.5-4.0 mm implant with guided bone regeneration or a short implant is appropriate; (4) place the implant after hygiene is stable, with a healing period that may be extended in smokers. I would tell him that smoking increases the risk of failure and peri-implantitis, and that cutting down is better than nothing but not equivalent to quitting. I would set expectations that the implant is not guaranteed and that maintenance will be more frequent. If he continues smoking heavily, I would still consider treatment but with informed consent about higher risk, and I would avoid immediate loading. The decision is a risk-benefit judgment, not a rule that smokers cannot receive implants.