Most endodontists max a 401(k), see the contribution limit, and assume that is the ceiling on tax-advantaged retirement savings. It is not. It is the floor.
A cash balance plan is a type of defined benefit plan built for high earners. Because contributions are actuarially calculated against a target retirement benefit rather than a flat annual cap, an owner in the right age and income band can shelter $150,000 to $290,000 a year, on top of what a 401(k) already allows.
The reason it fits endodontists specifically: you are typically a high, stable earner with few or no employees relative to revenue. That keeps the required contributions for staff low and the owner's share of the plan high.
The tax effect is immediate. Every dollar contributed is deducted this year. Shelter $200,000 at the top federal rate and that is roughly $74,000 you keep instead of send to the IRS, every year the plan runs.
It is not free money or a gimmick. The contributions are real retirement savings you cannot touch until retirement age, and the plan requires an actuary and annual administration. But for an owner already earning well and looking for the biggest legal deduction available, nothing else on the menu compares.
The only question that matters is whether anyone has run your numbers. Most owners have never been shown the ceiling, which is exactly why they contribute a fraction of it.