Is infection a risk of having a tooth pulled?

Infection is a possibility. It is important to keep the extraction site clean and clear. Doing so will allow it to heal healthy and avoid any potential problems, such as infection. Heeding your dentist's post extraction regimen is important for this reason.

Any surgical procedure is at risk for infection. When a tooth is extracted (pulled) it leaves an open socket that takes time to heal. In a healthy non-smoking adult, it is not likely that an infection will develop. However, all precautions should be taken to avoid an infection from developing. Good oral hygiene, soft diet, eating on the opposite side of the extraction, and warm salt water rinses after each meal to prevent food from packing into the socket site, will help prevent an infection and will heal faster.   

Randall D. Stastny, DMD
Oral & Maxillofacial Surgery
As with any surgical procedure, infection is always a risk. However, the oral cavity has an amazing capacity to heal itself. It is very important to keep things very clean after the removal of a tooth. To do this you should rinse with warm salt water after every meal, brush at least twice daily and follow any other instructions your dentist has given you. Do not pick at the extraction site as this may cause the healing blood clot to come out of the socket. If you do develop an infection your dentist can prescribe you an antibiotic. Signs of infection include increasing swelling past the third post-operative day, drainage from the site or increasing pain.
Infection can develop after you have a tooth pulled (extracted), although it isn't likely if your immune system is healthy. If infection is present before your tooth is pulled, your dentist may prescribe antibiotics as a preventive measure.

It is especially important to maintain good oral health when you have a tooth pulled. Have your teeth cleaned prior to the extraction, and practice good dental hygiene afterward. To keep the area clean, rinse your mouth with warm salt water starting the day after your extraction. Mix one-half teaspoon of salt in a cup of warm water and rinse several times. Your dentist also may recommend an antiseptic solution. If you notice any sign of infection, such as fever or swelling, contact your dentist right away.