IntermediateTECHNICAL
Walk me through your clinical reasoning when selecting between a direct composite restoration and an indirect restoration for a posterior tooth with a large cavity. What patient- and tooth-related factors influence your decision in general practice?
Dental Student
General

Sample Answer

I start by looking at remaining tooth structure and functional demands. For a posterior tooth with a large MOD lesion, if I’m losing more than about 50% of cuspal width or the marginal ridges, I lean toward an indirect onlay or crown to prevent fracture. If I still have strong cusps and can keep the isthmus under roughly one‑third of the intercuspal width, a bonded composite can work well. I also factor in occlusion (bruxism, heavy contacts), isolation, and caries risk. A high‑caries, bruxing patient who’s already lost one cusp is a poor candidate for a big direct; that’s where an indirect with cuspal coverage and possibly a nightguard makes sense. Then I layer in patient factors: budget, insurance, and time. For example, I’ve had students manage costs by doing a well‑designed direct first, then upgrading to an indirect when finances improve, while clearly documenting the higher fracture risk.

Keywords

Assessment of remaining tooth structure and cuspal involvementRole of occlusal forces, isolation, and caries risk in material choiceBalancing biomechanics with patient finances, expectations, and timingTransparent communication about fracture risk and long‑term prognosis