Dentists are a lot like software developers - they're not interchangeable. Just like if you ask two software developers what needs to be done to solve a problem

Dentists are a lot like software developers - they're not interchangeable. Just like if you ask two software developers what needs to be done to solve a problem you're going to get at least two different answers, the same is true for dentistry. Actually it's true of any professional service. We all have our biases for risk, we all have biases for wanting work - we all have biases. Those biases will manifest themselves in our recommendations for a course of action. That's why they say to get a second opinion. It's not just to assess whether the first opinion is off-base, it's to get a better assessment as a non-expert as to what you're up against and what course of action you should take.