Class IV lasers are primarily indicated for:

Class IV lasers are powerful devices used in various medical and dental applications due to their high energy output. They are primarily indicated for the ablation of tissue, which involves the removal or destruction of tissue for therapeutic purposes. This capacity makes them essential in surgical procedures, where precise and efficient tissue removal is required, such as in skin resurfacing or lesion removal.

In contrast, other applications such as caries diagnosis, polymerization of composites, and amalgam removal typically involve lower-powered lasers or different techniques. Caries diagnosis focuses on detecting dental decay rather than removing tissue. Polymerization of composite materials often uses specific curing lights designed for that function rather than a Class IV laser. Amalgam removal does not generally require laser treatment as it involves mechanical methods for removal. Thus, the primary application of Class IV lasers in the context of the options provided aligns with their intended use for tissue ablation.