Dr. Gianmarco O'Brien, DDS

Prosthodontics  |  
Male  |  
Age 43
Dr. Gianmarco O'Brien, DDS
Dr. Gianmarco O'Brien, DDS is a dentist who practices in Orange, CA. He is 43 years old and has been practicing for 14 years.

1140 W La Veta Ave Ste 530

Orange, CA 92868

Contact Information
Dr. Gianmarco O'Brien, DDS

Dr. Gianmarco O'Brien, DDS

Learn about Dr. O'Brien


Practice Areas

  • Prosthodontics
  • Cosmetic Dentistry
  • Dentistry
  • Emergency Dentistry
  • Family Dentistry
  • Minimally Invasive Dentistry
  • Neuromuscular Dentistry
  • Orofacial Pain Dentistry
  • Reconstructive Dentistry
  • Sedation Dentistry
  • Special Care Dentistry
  • Sports Dentistry

Conditions Treated

  • Cavity
  • Chipped Tooth
  • Dental Disorders
  • Edentulism
  • Gingivitis
  • Grinding of Teeth
  • Gum Disease
  • Phobia
  • Sleep Apnea
  • TMJ
  • Tempormandibular Joint Pain
  • Tooth Abrasion
  • Tooth Abscess
  • Tooth Attrition
  • Tooth Decay
  • Tooth Demineralization
  • Tooth Discoloration
  • Tooth Loss
  • Toothache


  • Composite Fillings
  • Dental Bonding
  • Dental Bridge
  • Dental Crown
  • Dental Implant
  • Dental Inlays
  • Dental Onlay
  • Denture Repair
  • Lower Dentures
  • Non-Surgical Gum Treatment
  • Porcelain Veneers
  • Restoration of Dental Implants
  • Root Canal
  • Root Planing
  • Simple Tooth Extractions
  • Teeth Extraction
  • Teeth Scaling
  • Teeth Whitening
  • Ultrasonic Dental Cleaning
  • Upper Dentures

Background Check

0 Malpractice Claims

No malpractice history found for California.

0 Sanctions

No sanctions history found for the years that Healthgrades collects data.

0 Board Actions

No board actions found for the years that Healthgrades collects data.


  • Santa Clara University
    Undergraduate School | Graduated 1996
  • University Of The Pacific / School Of Dentistry
    Medical School | Graduated 2003
  • Prosthodontics (Prosthetic Dentistry)
    Residency Hospital | Completed 2006
  • University Of California, Los Angeles. (UCLA)
    Residency Hospital | Completed 2006

Awards & Recognition

Awards & Honors

Dr. O'Brien has no awards or honors listed.

Media & Publications

Dr. O'Brien has no media or publications listed.

Languages Spoken

  • English

Memberships & Professional Affiliations

Dr. O'Brien does not have any memberships or affiliations listed. If you are Dr. O'Brien and would like to add memberships or affiliations, please update your profile.

Dr. O'Brien's Reviews

Likelihood of recommending Dr. O'Brien to family and friends
based on 34 total reviews (16 with comments)
Dr. O'Brien's Performance
  • Trustworthiness
  • Explains condition(s) well
  • Answers Questions
  • Time well spent
Office & Staff Performance
  • Scheduling
  • Office environment
  • Staff friendliness
  • Average wait time
    Under 10 minutes
Patient Comments (16)
in Upland, CA |
500 characters wasn't enough to adequately describe the extraordinary expertise and attention to detail that this doctor has, so here's my continuation. If you really care about your teeth & the work being done, "and" if you really want the BEST IN CLASS, Dr. O'Brien is the DDS you must see! The best way I can explain it is... for me, it was like the difference in driving a reliable car then hitting lotto & switching to a top of the line Mercedes, BMW, Audi, Bentley or.... you get the picture!
in Upland, CA |
Dr. O'Brien is just incredible!! A few years ago I was referred to Dr. O'Brien by another dental practitioner.I wondered, "why is my appt scheduled for such a long time?" I had gone through a similar procedure w/another dentist a couple of yrs earlier & the same procedure only took a fraction of the time. In summary, DOC O'BRIEN IS TRULY AMAZING! If you really care about your dental work, this is the person to see. He's kind, considerate, & has a sense or humor! Top of the line dental skills!
in Santa Ana, CA |
I have been a patient of Dr. O'Brien's for two years. From my first experience, I was impressed with his knowledge and enthusiasm for my difficult case. He is great to work with, and I'm pleased to have been recommended to him. His professional confidence and communication ability has always given me a great level of comfort during the dentistry work needed, and final results. I would highly recommend Dr. O'Brien and the office to anyone in need of this level of dentistry expertise.
in Los Angeles, CA |
Dr. O'Brien is a magnificent dentist! He is a superb technician, a skilled artist and a perfectionist. He is very gentle and makes sure that you are comfortable. I am very pleased with the work he has done for me and my family. I highly recommend him.
Dr. O'brien is one of the best doctors I met. He is very friendly and extremely skillful in what he is doing. He will listen to you and write down the history about your teeth problems so that he would be able to come up with the wisest decision in order to treat your teeth problem. Thank you so much, doctor, for making the best crowns for me. I feel so much better after suffering for so many months of tooth pain. You cured it all.
in La Verne, CA |
5 stars for Dr. Gianmarco O’Brien Dr. O’Brien has been one of the best doctors that I have ever met. I felt so fortunate to have found him when he helped me with my crown-building after I had my root-canal treatments. He has been very friendly and is extremely skillful in what he is doing. His craftsmanship in building a crown is absolutely top-notch. When you go to visit Dr. O’Brien, you can feel the kindness that he has towards his patients. He will devote the time to listen to you, and w
in Anaheim, CA |
Dr. O'Brien took over my case (a miss-aligned implant) and came up with a treatment plan that was minimally invasive and produced excellent results. His attention to detail was amazing and his ability to communicate outstanding. His technique and hands on methods were the best I have ever experienced with a dental professional. His staff were friendly and went the extra mile to assist me with my case. Dr. O'Brien is simply tops in my book. He would rate 6 stars.
in cathedral City, CA now Auburn, WA |
Imy experience with Dr. O'Brien was the end of 2006 first of 2007 in the Palm Desert area. His care and work was excellent. He was in the process of moving to Orange County but made sure he completed what he had started in me. I highly recommend Dr. O'Brien. Very professional and caring!
in Huntington Beach |
Dr. O'Brien has an amazing work ethic. He is not only kind, but very professional, has great integrity and puts only excellence in the work he does. I love that he is a perfectionist. I would recommend him to all my friends and family. He is simply the very best.
in Oceanside Ca. |
Highly recommend Dr. O'Brien. Dr. O'Brien had my best interest in mind and was there to help me with my Dental needs. He is gentle, caring and trustworthy. Dr. O'Brien helped me tremendously and I am very thankful for this. I am very happy with the results I now have the best bite I have ever had and a smile on my face. Thank you, Dr. O'Brien
in Garden Grove, CA |
Dr O'Brien is the best! I highly recommend him.
Garden Grove, CA |
I wish that I had known Dr. O'Brien way earlier because it would have saved me so much pain, suffering, & money. Dr. O'Brien had to redo all these bad dental works that the other dentists did on me: crowns, bad crown smell, bad fillings, & bad coloring. No matter what problems I have, I can rely on Dr. O'Brien to fix them. I also went through a tooth implant with Dr. O'Brien, and it came out beautiful!! Everyone loves it!! He is so professional and gentle. I highly recommend Dr. O'Brien!!
Westminster, CA |
I have been going to Dr. O'Brien since 2009 and has since referred all my family members (husband, sisters, and brothers) to him because he is simply the best in his field!! His work speaks for itself - my crowns all look beautiful and actually work, too. He would often had to re-do the work the previous dentists messed up on me. My two front teeth - one implant and one a crown and he made them look so natural that no one can tell either are not my real teeth!! :)
in Irvine, CA |
He's very gentle and gives painless injections.
in Tustin, CA |
He is a very patient doctor and quite the perfectionist!
in La Palma, CA |
He is awesome, caring, and a very patient dentist. I had two dental implants and I am extremely satisfied with the results. Thank you so much Dr. O'Brien??????
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