Which of the following is best for disinfecting smooth (noncritical) surfaces in the dental office?

EPA-registered, hospital-grade surface disinfectants (the type of product 'Lysol' represents in this context) are formulated for healthcare environments and are generally preferred for noncritical clinical contact surfaces. Alcohol evaporates quickly (limiting contact time and efficacy against some organisms) and can even 'fix' organic debris to a surface, while plain ammonia is not a standard registered healthcare surface disinfectant.