Welcome to Our Practice

Welcome to Keen Family Dentistry, PC, Your Dentist in Rancho Cucamonga, CA

Welcome! The dental professionals at Keen Family Dentistry, PC are pleased to welcome you to our practice. We want all our patients to be informed decision makers and fully understand any health issues you face. That's why we've developed a web site loaded with valuable information about dental and dental problems and treatments. We encourage you to visit this site whenever you have concern about your teeth.

Our web site also provides you with background about our, staff, office hours, insurance policies, appointment procedures, maps, directions to our office in and other useful information. We know how hectic life can be and are committed to making our practice convenient and accessible. And we want you to feel confident that when you choose , you're working with doctors and other professionals who are qualified, experienced and caring.

Please take a few moments to look through this site to get a better feel for Keen Family Dentistry, PC's capabilities and services. We also invite you to email or call our office at any time to request an appointment or ask any questions. Thank you.

Contact Us

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Meet The Doctors

Learn Who We Are

  • Dr.
    C. Mark Keen

    Dr. Keen was born and raised in Southern California, living in the Rancho Cucamonga area since 1990. He graduated with a biology degree in 1985 from USC and from USC Dental School in 1989, following his passion for cosmetic dentistry. Dr. Keen’s ultimate mission is to deliver the highest quality dentistry for his patients in a gentle, caring environment. He has been in his Alta Loma office for over 20 years, dedicating his efforts to helping patients achieve healthy, happy smiles.

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  • Dr.
    Bryce Keen

    Dr. Bryce Keen is the oldest son of Dr. Mark Keen and Diana Keen. He was born in Upland, California and grew a passion for dentistry at an early age from watching his father work as a dentist. He attended Los Osos High School where he played second base for the varsity baseball team. He later graduated the top of his class at Whittier College receiving Summa Cum Laude honors with a major in Biology. Following in his father’s footsteps, Dr. Bryce Keen went to USC school of dentistry where he gained ample experience in general dentistry, oral surgery, endodontics, and is certified with Invisalign. Dr. Bryce Keen’s mission is to carry on the legacy of his father’s practice by providing quality, pain free dentistry with the most advanced methods in the field.  

  • Dr.
    Blake C. Kleen

    Graduating Class of 2023!

    Dr. Blake will be joining our office Summer 2023. Bio coming soon!


  • "I have been a loyal customer of Dr. Keen's for several years. Dr. Keen is the kindest. hard working, most caring dentist I've ever known. His workmanship is out of this world. Kudos to Monique, his Office Manager. She's the best office manager, ever. His whole team is amazing. Now let's talk about Luis; his gentle, thorough, and super patient. between Luis and Dr keen, your teeth are in safe hands."
    Dentrix Hub- Lavender I.
  • "Fabulous dentist!
    I moved into the area from out of state and was concerned about finding a good dentist. A co-worker recommended Dr. Keen and he is great!
    The office staff is very kind and take care of all of my insurance claims very efficiently.
    He recently replaced some 40 year old fillings for me and was so careful, gentle and concerned about me well-being during the two sessions needed to replace 7 fillings.
    My wife and I both go to Dr. Keen and recommend him to everyone."
    Yelp- Scott K.
  • "What can I say about Dr Keen?! UMMM HE'S A USC ALUMNI NEED I SAY MORE?! He is an amazing dentist! This is coming from a girl who much rather go through labor than see a dentist! He is so patient, so calm and so NICE like I can honestly see why people love him so much. My husband has been coming to him for years and while he's a bit of a drive for us, he's definitely worth it. The only downer at least for me is he doesn't work Fridays and weekends but it's ok I'm learning to work around it. Dr. Keen, thank you so much for taking care of me and my teeth, your patience really makes me feel more at ease coming to get dental work done"
    Yelp- Janice M.

Featured Articles

Read up on informative topics

  • Your Rights and Responsibilities as a Patient

    Patient Rights You have a right to choose your own dentist and schedule an appointment in a timely manner. You have a right to know the education and training of your dentist and the dental care team. You have a right to arrange to see the dentist every time you receive dental treatment, subject to ...

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  • Crowns and Bridges

    Bridges Bridges are natural-looking dental appliances that can replace a section of missing teeth. Because they are custom-made, bridges are barely noticeable and can restore the natural contour of teeth as well as the proper bite relationship between upper and lower teeth.Bridges are sometimes referred ...

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  • Veneers

    Teeth that are badly stained, shaped, or crooked may be improved by a veneer placed on the surface of the affected teeth.Veneers are thin pieces of porcelain or plastic cemented over the front of your teeth to change their color or shape. Veneers are used on teeth with uneven surfaces or that are chipped, ...

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  • Invisalign®

    Invisalign's® invisible, removable, and comfortable aligners will give you the beautiful straight teeth you've always wanted. And best of all, no one can tell you're wearing them. Invisalign® is great for adults and teenagers. What is Invisalign®? Invisalign® is the invisible way to straighten your ...

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Our Location

General Hours


9:00 am-5:00 pm


9:00 am-5:00 pm


9:00 am-5:00 pm


9:00 am-5:00 pm


9:00 am-5:00 pm