What distinguishes therapeutic lasers from surgical lasers in terms of their effects?

Therapeutic lasers are distinguished by their photochemical effects, which involve the interaction of light with biological tissues that leads to cellular responses without causing significant thermal damage. This characteristic is crucial for therapeutic applications, as it focuses on healing and regeneration rather than cutting or ablating tissue.

In contrast, surgical lasers primarily utilize their thermal effects to vaporize, cut, or coagulate tissue, which is necessary for surgical procedures. Thus, the emphasis on photochemical effects allows therapeutic lasers to promote processes such as increased circulation, reduced inflammation, and enhanced tissue repair, making them particularly effective in pain management and rehabilitation.

The other options do not accurately describe the primary distinguishing features of therapeutic lasers. For instance, the idea that they are more painful contradicts their purpose, which is to alleviate pain. While therapeutic lasers do generate some heat, it is the photochemical effect that is the hallmark of their functionality. Additionally, therapeutic lasers are not limited to just the skin; they can penetrate deeper tissues, thus aiding various conditions beyond superficial applications.