The human mouth is one of the dirtiest places on Earth in regards to bacteria and language. If a dog (or almost any other animal) bites you it is possible that it will become infected, especially if it’s a deep cut, but it is easily handled with antibiotics. Animals with rabies or some other disease of course may not be as easily treatable. When a human bites you it is probable that you will have a long hard fight against infection, no matter how deep the wound is.
The human mouth carries far more types of bacteria than any other animal, when a human bites another creature all those bacteria get inside the wound and cause infection. Usually the body can handle some infection, small wounds for example, but the human mouth puts more bacteria into the blood than the body can handle, deep would or not. Some people have had to have limbs amputated to avoid death due to a human bite, and even today that is sometimes a risk.
Now you mentioned in your question that the bite did not break the skin, that doesn’t mean that some of that horrible bacterium didn’t get into the blood stream. If there was bruising then there could have been a cut that you didn’t notice. It is not likely that a human bite that doesn’t break the skin would cause an infection but human saliva is so potent with bacteria that it is possible.
I did assume that you were referring to a human bite in your question. If it was an animal bite you are referring to it is much less likely that a bite that didn’t break the skin caused an infection.
If you haven’t already, see a doctor about this.
