Final answer:
The most common route of disease transmission in the dental office is direct contact, followed by airborne transmission and contamination of instruments or surfaces.
Step-by-step explanation:
The most common route of disease transmission in the dental office is direct contact. Pathogens can spread from person to person through skin-to-skin contact or by touching the same surfaces. For example, oral pathogens can spread through direct oral contact like kissing or sharing items that go in the mouth. Another common route of transmission is through airborne transmission, where pathogens in droplets are expelled from an infected person's respiratory system during coughing or sneezing and then inhaled by others.
Finally, contaminated instruments or surfaces in the dental office can introduce pathogens to the bloodstreams of patients through procedures like dental work or piercings.