Education:

  • BA Chemistry (2009), Iowa State University, Ames, Iowa
  • Doctor of Dental Surgery (2013), University of Iowa College of Dentistry, Iowa City, Iowa
  • Certificate in Endodontics (2015), University of Iowa College of Dentistry, Iowa City, Iowa

Special Professional Interests

Dr. Sullivan owes his interest in dentistry to his childhood dentist who proved that time in the dental chair did not have to be something to be feared. While in dental school, Dr. Sullivan developed a specific interest in endodontics, especially the nature of the procedures and the fulfillment that came in helping relieve people from pain. He elected to specialize and spent an additional two years at the University of Iowa in endodontic training. After completing the residency program, he joined The Dental Specialists.

Professional Activities

  • American Dental Association
  • Minnesota Dental Association
  • American Association of Endodontics

Verified Patient Reviews

4.9 out of 5 (333 Reviews) (134 Comments)

Overall patient ratings are based on the average score given by The Dental Specialists patients who voluntarily complete a satisfaction survey from Press Ganey, a nationally recognized firm dedicated to improving patient experience. Click to learn more about our patient ratings.

5 out of 5
April 25, 2022
Dentist and staff gave a lot of great information and described the process as they went, which helped calm me down.
2.3 out of 5
April 22, 2022
The dentist was professional and provided good advice. Sat at my shoulder so did not engage me in face to face communication during consultation. The assistant was excellent and brought the human touch to the appointment. I would not know the dentist as I never really saw his face . My impression was that I was simply another person on his list for the day.
5 out of 5
April 18, 2022
Dr. Sullivan has completed both of my root canals and the experience has been exceptional during both visits.
3.8 out of 5
April 11, 2022
Things went fine, though I would have preferred more explanation during the procedure as to what was happening.
5 out of 5
April 6, 2022
Both Dr and Assistant were very professional yet kind. Wonderful!
4.8 out of 5
April 6, 2022
Only just met the dentists. No work done yet. Both seemed really nice.
5 out of 5
March 31, 2022
Excellent service!!
5 out of 5
March 27, 2022
Both dr. Mark Sullivan and his assistant we're friendly, articulate and caring.
5 out of 5
March 17, 2022
Dr. Sullivan provided a clear explanation of the procedure and what other care I might need.
5 out of 5
March 17, 2022
Dr. Sullivan and the dental assistant Tracy were very friendly and made me feel at ease.
5 out of 5
March 16, 2022
Dr. Sullivan and dental assistant are an impressive team.
5 out of 5
March 7, 2022
I was very pleased with the quality care I received.
5 out of 5
March 3, 2022
Not nervous at all.
5 out of 5
March 3, 2022
No delays
5 out of 5
March 3, 2022
This will be my third treatment at TDS. The reason is the quality and care offered.
5 out of 5
February 28, 2022
No delays, short wait time.
5 out of 5
February 24, 2022
Dr. Sullivan was incredible. He did not rush us in anyway make sure we understood everything. I couldn't say enough positives about his assistant as well she too was incredible. I would absolutely recommend them to anyone.
4.8 out of 5
February 17, 2022
Wish the dentist gave more updates throughout the procedure regarding the progress of the procedure. It would have helped ease my anxiety to know we were moving along and when the filling was being placed. In general, a good experience though and I appreciated the phone call the next day.
5 out of 5
February 16, 2022
Great service
5 out of 5
February 16, 2022
Good experience. No problems
5 out of 5
February 16, 2022
Very professional
5 out of 5
February 15, 2022
Good Experience for a first time root canalReally liked dental assistant. Made me feel so comfortable and that a good dentist was doing my work. She was great.
5 out of 5
February 15, 2022
Very pleased with Dr Sullivan. Professional and Personable.
5 out of 5
January 24, 2022
Young , very efficient, he told me what he was doing when I might have some discomfort. I had none. Was surprised it didn't take longer.
5 out of 5
January 21, 2022
I thought Dr. Sullivan and his assistant both did a great job. I really appreciated the follow-up call from the doctor the day after my procedure.
5 out of 5
January 17, 2022
No delay, they were cheerful and reassuring from the moment I walked in.
5 out of 5
January 17, 2022
I have already told others how wonderful Dr Sullivan was
5 out of 5
January 13, 2022
I was never nervous or afraid during my visit; I attribute this in large part to the routinely calm demeanor of the staff in general.
5 out of 5
January 13, 2022
Dr. Sullivan was comprehensive in his explanation of the problem and solution, and in laymen's terms. I appreciated his relatable candor.
5 out of 5
January 13, 2022
Dr. Sullivan did a great job of explaining what he was seeing and what he thought was causing the tooth pain and the best way to fix the problem.
5 out of 5
December 30, 2021
The dentist called to check to see how things were going the next day, very happy!
5 out of 5
December 24, 2021
Dr, Sullivan explained the procedure, prognosis well. I had no pain during the procedure or afterward. He was efficient and professional. I also appreciated the follow up call the next day.
5 out of 5
December 24, 2021
Dentist was excellent very informative and respectful
5 out of 5
December 24, 2021
Great staff very welcoming and informative of everything and the billing process
5 out of 5
December 24, 2021
Excellent I sat down filed out the clipboard and they called me within a mn super fast and I was early for my appointment
5 out of 5
December 22, 2021
my assistant and Dr. Sullivan were excellent--friendly, thorough and attentive.
5 out of 5
December 22, 2021
All excellent
5 out of 5
December 15, 2021
I really appreciated the doctor calling to check on how I was doing a few days after the procedure. I believe I saw Dr. Sullivan. He was great. Very patient-centered.
5 out of 5
December 14, 2021
Mark Sullivan is a steely-eyed, John Prine-listenin', root canaling master.
5 out of 5
December 14, 2021
No fear, unlike the first time. Dr. Sullivan handled the first molar with patience and efficiency. Very friendly, and had a conversation with me about my care and treatment. Everyone in the office was there to facilitate my care and make me feel at ease. Dr. Sullivan handled both my tricky root canals flawlessly. While doing the second one, he paused the procedure to extract a 'tooth stone' that had formed in the pulp of the molar before continuing the procedure. Amazing.
4.4 out of 5
December 8, 2021
Dr Sullivan very informative very caring and honest in his decision very knowledgeable and very intelligent he is so calming too
5 out of 5
December 8, 2021
Excellent!
5 out of 5
December 7, 2021
The Endodontist was outstanding!
5 out of 5
December 7, 2021
Outstanding service!
5 out of 5
November 22, 2021
Dr. Sullivan was spectacular. He verbally talked me through the whole process, was patient with questions, and caring. I have given his information to two friends already!
5 out of 5
November 22, 2021
Dr. Sullivan was really great. This was my first time seeing him and my first root canal and I was very nervous and scared. He explained everything really well and with visual aids, from the consultation through to the procedure. He was also good at letting me know how I was doing and how things were going. I only wish he would have given me time checks so I knew how long I still had to go. His assistant was awesome, too - she gave me tissues and rubbed my arm and gave me suggestions to help calm me down.
5 out of 5
November 6, 2021
I had an excellent experience with Dr. Sullivan and his dental assistant were incredible - his dental assistant was so sweet, listened to my nerves, calmed me down by consistently talked me through everything. She was incredibly kind and supportive throughout the entire procedure. Dr. Sullivan was very thorough and took me through everything. He ensured I understood my options, gave me time to ask questions, and addressed my concerns. I would highly recommend both of them to anyone!
5 out of 5
October 29, 2021
Dr. Sullivan takes time to explain everything.
5 out of 5
October 19, 2021
Procedure was quick and painless. Wished the doctor would have provided information on the progress. Like we can see the roots, completed one , second one etc just to let me know of the progress
5 out of 5
October 19, 2021
Appreciated the follow up call by the dentist to see how I was doing
5 out of 5
October 15, 2021
I appreciated that Dr. Sullivan was honest with me that the tooth was not worth saving or doing a root canal.
5 out of 5
October 13, 2021
The dental assistant and endodontist (Mark Sullivan) were both friendly and professional. The procedure was explained thoroughly to me and was painless.
5 out of 5
October 7, 2021
Dr Sullivan explained things very well
5 out of 5
October 7, 2021
Dr Sullivan called me the next day to see how I was. That was nice.
5 out of 5
October 5, 2021
Dr Sullivan walked through the procedure which I appreciated
5 out of 5
September 2, 2021
Dr. Sullivan was very good at explaining the procedure and processes. He wanted to ensure I was not in pain. I am so grateful to have been under the care of an excellent specialist.
5 out of 5
September 2, 2021
The staff and Dr. Sullivan were wonderful! The assistant asked what kind of music I wanted to listen to during the procedure bringing up Pandora and what they had available. Dr. Sullivan followed up with a phone call the next day to see how I was doing. I would highly recommend your practice.
5 out of 5
August 27, 2021
We loved Dr Sullivan. He did a great job.
5 out of 5
August 27, 2021
Dr. Sullivan has now done 3 root canals for me and I won't go anywhere else! He explains things well and made sure I was comfortable during the entire process. He is quick and efficient working well with his staff.
5 out of 5
August 23, 2021
Dr. Sullivan took time to explain the entire process of the root canal and kept me updated as he worked on my tooth. I was quite nervous and he eased my concerns.
5 out of 5
August 23, 2021
Dr. Sullivan was, in all aspects considered, exemplary.Inclusive without being obsequious, and gracious without being fawning, I left the potentially awkward situation very pleased.And the front desk scheduler/receptionist were equally kind and competent.
5 out of 5
August 4, 2021
I had a great experience with both Dr. Sullivan and Dr. Peterson. Both were very good at explaining what was needed and why.
5 out of 5
July 24, 2021
Dr. Sullivan was/is very professional, focused, and easy-going - and I appreciated his "bedside manner."
4.4 out of 5
July 20, 2021
Being in the chair is never pleasant for me. I was nervous with this being a new experience. Things were explained well, and I was told I was the boss. Overall a good experience.
5 out of 5
July 14, 2021
Dr. Sullivan and his assistant were exceptional. Front desk person was also excellent.
5 out of 5
July 14, 2021
Amazing experience!
5 out of 5
July 2, 2021
Dr. Sullivan and his assistant, were absolutely amazing! They made me feel comfortable in my nervous state and I love how transparent they were in their communication.
5 out of 5
June 11, 2021
Dr Sullivan was calm, friendly, efficient and took the time to explain the procedure and what was and wasn't going on with my teeth. He listened to what I said, answered my questions and asked me relevant questions to determine the best action.
5 out of 5
June 11, 2021
Dr. Sullivan is a rock star.
5 out of 5
June 2, 2021
Dr. Sullivan did a wonderful job taking time to explain what he was doing and making sure I was not in pain. Thank you, thank you, thank you!
5 out of 5
May 7, 2021
Dr. Sullivan and his team took the time to answer all my questions concerning my treatment. and were able to accommodate all my special requests.
4.8 out of 5
April 28, 2021
Nice job done.
4.8 out of 5
April 28, 2021
Nice practice.
5 out of 5
April 7, 2021
great chairside manners
5 out of 5
March 29, 2021
excellent team that treated me
5 out of 5
March 29, 2021
All of Dr. Sullivan's instructions were careful and thorough and he answered my questions and even drew a diagram for me. I was so very impressed.
5 out of 5
March 17, 2021
I appreciated that Dr.. Sullivan's had a 3D X-ray to diagnose the condition of my bicuspid. I did not need a root canal, however, I had a cracked tooth. He referred me back to my dentist to treat the tooth.
5 out of 5
March 12, 2021
Thank you
5 out of 5
March 5, 2021
he was absolutely wonderful!
4.9 out of 5
March 3, 2021
Thank you!
5 out of 5
March 1, 2021
The Doctor called me the next day to check on me. I thought that was wonderful - over and above duty. We are very satisfied.
5 out of 5
February 12, 2021
Could not have been better
5 out of 5
January 26, 2021
Very happy to have seen/met Dr Sullivan. And a nice touch with the follow-up call.
5 out of 5
January 10, 2021
just outstanding care
5 out of 5
December 9, 2020
Excellent!
5 out of 5
November 11, 2020
I am very impressed with Dr. Sullivan, his dental assistant and your office staff and appreciated his time and expertise and the treatment plan he suggested that I am going to pursue with him and your staff.
3.2 out of 5
November 9, 2020
I wasn't given much in the way of after care instructions or what to look out for as far as infection etc.
5 out of 5
October 30, 2020
did a very good job, took time and explained what he was doing
5 out of 5
October 29, 2020
Superb care and knowledge. Highly recommend
5 out of 5
October 12, 2020
Dr. Sullivan and his nurse/assistant explained what they were going to do throughout the procedure. This was very helpful in helping me remain calm. Additionally, prior to the root canal Dr. Sullivan explained tooth pain and how the nerves react in one's mouth. I appreciated that he knew I would understand, and I liked learning something new about teeth.
5 out of 5
September 30, 2020
doctor Sullivan was amazing. great bedside manner explaining everything and ensuring all was smooth. appreciate the follow-up call from the actual dentist.
5 out of 5
September 15, 2020
This was the first time I had been to an endodontist in my life. Dr. Sullivan was very good in explaining my treatment options and was very good at answering my questions. I would rate my overall experience with Dr. Sullivan as excellent.
5 out of 5
August 25, 2020
first class !
5 out of 5
July 31, 2020
Dr Sullivan provided a clear explanation of expectations. Although the office was very busy he did not seem rushed at all.
5 out of 5
March 16, 2020
wonderful doctor, so pleasant and very professional
5 out of 5
February 27, 2020
dr Sullivan called me the next day!! not the office personnel, the doc! He was also very polite to and respectful of the hygienist and me. Dr Sullivan was very calm, explained every thing and made a root canal a "pleasant" experience!
5 out of 5
February 26, 2020
Exceptional treatment, had a root canal done on my back #1 molar. Dr. Sullivan found just the right spot for the anesthetic shots, which at other dentists have left me sore for days. This time when I went home and the anesthetic wore off I had no pain or soreness - didn't even need a Tylenol! Way to go Dr. Sullivan - informative, educational and all-around nice endodontist!!!
5 out of 5
January 25, 2020
Dr. Sullivan did an excellent job explaining the procedure and his thinking for what he was planning to do. He had the diagnostic image available to show me exactly what the problem was and how he would treat it. I had many questions, and he patiently answered every one. I appreciated the "crash course" in endodontics I received. I felt not only assured that I was in good hands, but I knew what was happening at every step of the way. I left better educated about the procedure and about basic jaw anatomy.
5 out of 5
January 16, 2020
Dr. Sullivan put me at ease by explaining what the procedure and process.
5 out of 5
December 28, 2019
Dr. Mark Sullivan was very good: professional, pleasant, calming, and informative and efficient. I recommend him back to my dentist to use Dr. Sullivan for referrals.
5 out of 5
December 27, 2019
Dr Sullivan and Hygienist were awesome, BEST dental experience I've had in years
5 out of 5
November 12, 2019
Dr Sullivan explained any concerns I had and the staff is great and friendly.
4.3 out of 5
November 6, 2019
I was not aware that 1) a filling will be required in addition to the root canal, 2) a temporary filling was used, and I will need to return to office for another visit to get a permanent filling.
5 out of 5
October 25, 2019
great chair-side manner by Dr and assistants.
5 out of 5
October 24, 2019
Dr. Sullivan was excellent. He had a very calm demeanor and explained things thoroughly to me. He took time and didn't rush into the procedure.
5 out of 5
October 7, 2019
so wish Dr Sullivan could be my dentist for everything :)
5 out of 5
October 7, 2019
Dr called following day to see how I was doing
5 out of 5
October 1, 2019
Dr. Sullivan followed up the next day (after a root canal was retreated). This doesn't happen with all doctors and dentists.
5 out of 5
October 1, 2019
Dr. Sullivan and his team were excellent. Really made me feel at ease while undergoing a re-treatment for a root canal.
5 out of 5
August 30, 2019
Very pleased with Dr. Sullivan, He made me feel very comfortable during the procedure. I had no pain or issues afterwards. Also the phone call I received from Dr. Sullivan the next day to check how things were going after procedure. I would highly recommend anyone to come to your office. Thank you Dr. Sullivan
5 out of 5
August 19, 2019
I was most appreciative of the time the specialist spent with me explaining all facets of what the issue was and how it was to be addressed.
5 out of 5
August 2, 2019
Very good explanation of the problem and potential solutions
5 out of 5
July 19, 2019
Dr. Mark Sullivan is a very caring Doctor. I am forever grateful to him for putting a smile back on my face.
4.8 out of 5
July 3, 2019
good initial visit
4.9 out of 5
May 9, 2019
due to Dr. Sullivan's examination and observation, the root canal was done on the adjacent tooth rather than the one originally planned.
5 out of 5
May 1, 2019
I have a lot of confidence in Dr. Sullivan and he is very respectful. Inspires confidence.
5 out of 5
April 27, 2019
Treatment went well.
5 out of 5
April 17, 2019
I was very happy and impressed with Dr Sullivan's "bedside manner" in talking through the options and treatment. He explained everything in layman's terms with drawings and competently took my questions with patience
5 out of 5
March 7, 2019
Dr Sullivan was very professional and even made a phone call to see how I was doing.
4.9 out of 5
March 6, 2019
Dr. Sullivan was excellent! I appreciated his calmness as I was very nervous getting a root canal! He showed great care for my well being and gave me a heads up throughout the procedure so i would know what to expect. He gave me a follow up call the next morning to see how I was doing - what a great courtesy!!!
5 out of 5
February 28, 2019
Dr. Sullivan was very pleasant to meet with and quickly established to me his credibility.
4 out of 5
February 27, 2019
Excellent treatment during root canal- no resting hands on my mouth/lips, hitting teeth with tools, etc. I appreciated the vocal "next steps" as he was performing work, and even reccomended his skill after I returned to my office. HOWEVER, within hours I developed a complication (Endodontic Flare-up) and he was resistant to acknowledge something might be wrong (IT WAS) and that perhaps a more serious painkiller or exam was necessary. It took 2 emergency after-hours phonecalls and a another call with the clinic the next morning to get another doctor to see me. It's troubling to be dismissed for a legitimate medical issue- especially when I have such personal experience- and where PAIN was being blatantly ignored and downplayed as "discomfort."
5 out of 5
February 26, 2019
I had great confidence in Dr. Sullivan! He explained everything very well and eased my worry.
5 out of 5
February 8, 2019
Received a follow up call from the doctor. Very professional!!!
5 out of 5
January 30, 2019
I appreciated Dr. Sullivan calling me the morning after my appt.
5 out of 5
January 27, 2019
Absolutely outstanding doctor!!!
5 out of 5
January 17, 2019
Dr. Sullivan was great. I would highly recommend him. No pain during my root canal.
4.9 out of 5
January 4, 2019
Would have been nice to have something in writing to take with me on "eat soft foods, rinse twice daily..."