Best Dentistry
Donghyun Koo, DDS:
Practice Profile Page


Best Dentistry
Donghyun Koo, DDS
Seattle, WA













A list of major dental treatments which I offer my patients:

Dental cleaning

White fillings


Inlays & onlays


Clear aligners

Porcelain veneers

Teeth whitening

Dentures & partials

Root canal treatment

Tooth extraction

TMJ treatment

Dental implants


Offers Even28 at-home™? No

Offers Even28 at-dentist™? No

Offers Invisalign®? Yes


Monday: 8:00 am to 5:00 pm

Tuesday: 8:00 am to 5:00 pm

Wednesday: Closed

Thursday: 8:00 am to 5:00 pm

Friday: 8:00 am to 5:00 pm

Saturday: 8:00 am to 1:00 pm

Sunday: Closed


Dr. Donghyun Koo, DDS





Check out what some of our happy patients are saying about us:

Ricardo M. from La Puente, CA (Source: Yelp)


Do not think twice about coming to this dentistry, I’ve received nothing but quality service from this place since I’ve started getting work done. Both my Root canals and wisdom tooth extractions have gone perfect. At first I was terrified of going to the dentist, however after you talk to them, they will work with you and give you medication to have the procedures go very smoothly. Make sure to ask for Dr. Koo, he is extremely experienced and professional. He understood that I was worried and anxious and walked me through everything,  my procedures were quick and painless. I hardly ever leave reviews online unless I have an extremely good experience. This is one of them. I cannot recommend this place enough!

Molly Snodgrass (Source: Google)


I’ve had extensive dental work across many dentists/orthodontists, but still get very anxious with any appointment. So far, Best Dentistry lives up to their name as the best I’ve experienced! Everyone is very attentive, kind, and put me at ease with each procedure. They make everything comfortable, quick and painless as possible. Shout out to Marco too for all of his help with the scheduling, insurance and billing. So thankful I’ve found my go-to dentist!

Megan M. (Source: Zocdoc)


I was a new patient for best dentistry – I was treated with kindness and Dr. Koo talked me through how to best maintain my dental hygiene by showing me photos and X-rays of my teeth and explaining why certain dental hygiene tasks are important. I immediately trusted his judgement and have found my new regular dentist! Also a great central location for Ballard, Greenwood, and blue ridge neighborhoods.

T.B. T. from Los Angeles, CA (Source: Yelp)


*This place will make you look forward to go to the dentist!* I live in L.A. but Arcadia Dental’s service has kept me driving back for over 6 years. I was originally referred for an extraction of my upper wisdom teeth by Dr. Koo. I felt absolutely nothing! I have continued to go for regular exams & cleanings by my favorite Hygienist, Miss Rose (highly recommend). She is simply THE BEST; very caring, thorough & knowledgeable. Her comforting energy soothes away any anxiety I may have. I am always pleased with her service. I also love the quaint office and friendly staff, and I am never there long. By far, the most satisfying office I have been to.

Jesseca Wang Eskander (Source: Google)


Dr. Koo, Marco, and all staff at Best Dentistry are amazing and always so welcoming. Dr. Koo is great at what he does, very professional, and friendly. My husband and I used to live down the street from Best Dentistry, but have moved 25 minutes away. We have chosen to continue to come here because of the wonderful service that’s provided.

Irene S. from Pasadena, CA (Source: Yelp)


I had to have some work done on my teeth and was recommend to the Arcadia Dental Group. First my teeth were cleaned by the hygeinist Frances. Easily the highlight of the day. You could tell she cared and it was the least painful clean I have ever had. Dr. Koo did the work on my teeth. I could not be happier. This was my second dentist I had gone to for this work the first one wanted to charge me an arm and a leg and do much more work then was necessary. Dr Koo did and amazing job and after insurance if was very reasonable. I highly recommend the Arcadia dental group.

Robert B. from South El Monte, CA (Source: Yelp)


Today I called to see if my daughter can be seen because she had a loose tooth and was having pain. I spoke to Sonia and she said come right in, we will see her.  Upon our arrival we were greeted by friendly smiling staff.  Dr. Koo and his assistant Lourdes were great.  Dr. Koo put some numbing gel and pulled my daughter’s tooth.  My daughter turned and said thank Dr. Koo and Lourdes.

Elvis Hrustic (Source: Google)


hello, i dont usually write reviews but dr. koo and his associates deserve this. just so you know he is my dentist for life!. about 1 year ago my mouth in my pain has gotten so severe that it was giving my headaches for about a year and i never knew where those headaches were coming from found out after visiting a few dental areas that 7 of my teeth were infected and i needed 7 extractions, i had a family member telling me about best dentistry and i decided to go here. we first chatted about the steps we will be taking and we did 7 extractions in 2 appointments. (felt barely a pinch) i had some stitches done (no pain) also how severe my teeth were, after not having sleep for almost 2 years i was able to sleep because of dr.koo i am able to eat normally i am able to not having my emotions all over the place because of the combined infection and lack of sleep and the throbbing pain i had to deal with 20 hours a day for years. idk how to say this but he probably saved my life. theirs not one appointment they havent called the next day to see how im doing. their a amazing team and marco has always been a pro on helping me set up future appointments. i have had issues with other dentists how rough they were and some unprofessional on how they went about my teeth but doctor koo understood my fear and pain. i dont know what to say but THANK YOU is not enough for doctor koo and his team. they are currently doing bridges on my teeth for me and guess what?? NO PAIN!. they are fast, they are reliable, and not one time i haven’t seen them without a smile!. they should change the name of their dentistry to the GREATEST DENTISTRY THAT EVER EXISTED!. PERIOD. thank you so much is not enough how they helped me through this journey!!. they deserve all the praise in the world. thank you all of you at BEST DENTISTRY! you really are the BEST!. PERIOD!.

Audrey C (Source: Google)


Visited Best Dentistry for an emergency dental appointment and was able to obtain an appointment for the next day. They were highly accommodating of my schedule and maintained proper communication prior to my appointment. When I arrived, I was greeted by a clean office space with professional and kind staff. Moreover, I felt as if the entire appointment was quick and efficient. They assessed the issue with my teeth and walked me through every step of the process. Since this was my first time here, Dr. Koo was patient with me and explained to me everything he was doing. I usually loathe going to the dentist office, however, this entire experience was quick and seamless. Overall, I would definitely recommend this place to anyone.

QZ C. from Pacific Palisades, Los Angeles, CA (Source: Yelp)


I’ve been going here for 5+ years. My overall experience has been great. Originally, I went to see Dr. Koo for painful toothache caused by my wisdom teeth. He was very professional and the procedure went smoothly. Now I’m still going to the Arcadia Dental group, mainly because of my hygienist – Rose! She is calm, detail oriented and truly care about her patient. She always checks to make sure I feel comfortable during the cleaning process and she listens to my concerns and gives me tips for Dental hygiene. My teeth are a lot better now.

Franklin K. from Los Angeles, CA (Source: Yelp)


My Wife had been coming to Dr. Koo and Amanda for quite some time now and have been receiving great care and service.  I finally came in for my first time this week and now can see what my Wife was talking about and truly get to experience great service.  Special shout out to Dr. Nguyen, Francis, Martha, Linda, Cindy, Sonya, and Crystal who all helped from the moment I booked my appointment over the phone to my dental cleaning and crown preparation.  I will be getting my permanent crown soon and look forward to it.

Young Yoo (Source: Google)


After relocating recently from my long time home of Los Angeles, I was nervous about finding a dentist in a new city. However, after hearing glowing recommendations about Dr. Koo from my co worker, I scheduled a much needed dental cleaning which I delayed due to fear of covid-19. The appointment process was super simple with a quick phone call and text confirmation. When I arrived to my appointment, I quickly filled out the new patient form and got treated right away with ZERO waiting time!!!! Dr Koo was very professional and was extremely attentive to detail. When he saw I had some concerns regarding covid, Dr Koo went out of his way to address all my concerns with explanation of how he sanitizes every instrument/tools/spots patients have touched. additionally, all of his staff members wore masks and were vaccinated. The dental cleaning was extremely thorough and to my satisfaction! I’m glad that I was able to find my new go-to dentist here in Seattle (yay! One thing less to worry about in a new city!)

Usa Y. from Monterey Park, CA (Source: Yelp)


Great dental group. Nice, clean looking professional office, plenty of room in the waiting area, friendly receptionists, knowledgeable, helpful dental assistants. Advice and dental works receive demonstrate that these doctors are SME in their field of practice; they perform required procedure fast without rushing, this key to professionalism. Dr. Koo is the go-to, can-do guy there, just ask him what you need; btw, he is the extraction king. Dr. Leung puts patients at ease and is very thorough. Dr. Nguyen is quick, friendly, reassuring, and unbiased. Happy to write this review, just want to help everyone out there to find a good dental operation…give these doctors a try for any and all your dental needs. My family goes there for cleaning, extraction, filling, braces, pediatric service, crowning, root canal, whitening… Keep up the good work Arcadia Dental!

Ryan H. from La Verne, CA (Source: Yelp)


I have literally been coming here since I was old enough to see a dentist, and my mom since her 20’s, back when it was just Dr. Koo. They quickly grew over the years, for their staff has remained the friendliest, most well trained, and experienced dental staff in the SGV. They’re always willing to answer questions and always make you feel comfortable. I have tried other dentists, but no office is even comparable to this one, which is why as long as I live in California, this will be my dentist!

Marlene M. from Monrovia, CA (Source: Yelp)


I had a bad experience a while back with the front desk, but Dr. Koo personally got a hold of me and made me feel better about the situation.  He personally took the time to get a hold of me. (not too many people out there will give anyone the time of day but he did.)  Dr. Koo takes really good care of his patients. My mother in love would always talk so highly of him and now I know why.  My husband and I have an upcoming appt and we are excited to get work done by him.  If you are looking for a family dentist that cares for his patients and will go above and beyond for your needs, this is the place to go.

Nikita C. from San Diego, CA (Source: Yelp)


I’ve been coming to Arcadia Dental Group for over 5yrs for all dental work and teeth cleaning. What I discovered over the years is how effective teeth cleaning can be and how it helped me maintain healthy teeth. All thanks to Hygienist Rose. I specifically asks to see Rose on all my teeth cleaning visits,and my insurance allows me to have 3 teeth cleanings a year. Rose is so meticulous and patient in cleaning my teeth thoroughly every time. Rose is truely a professional hygienist whose work performance will definitely exceed your expectations. Rose really deserves to be complimented for her quality of work and attention to details. Ask for Rose for your teeth cleaning needs and I guarantee that you won’t be disappointed. Now I just hope it won’t be too difficult for me to get an appt with her after I shared this secret… 😀

Marco S (Source: Google)


I cannot say enough good things about this practice, and Dr. Koo! Very welcoming, and knowledgeable staff from start to finish. Also, VERY fair prices! My teeth whitening was only $200, as where most facilities are charging $800- $1000. Seriously couldn’t believe it! 🙂 They do an excellent job with COVID guidelines to ensure the safety of both patients, and staff. I really appreciate how much effort and time was put into addressing my concerns. Couldn’t be happier with the care I received! 🙂 Full service dentistry, with wholesome hometown comfort. Thank you Dr. Koo & Team!

Omar Simon (Source: Google)


BEYOND satisfied! I am so relieved to have found a place that was very understanding of my situation— Dr. Koo was very patient, gentle and kind. I know it sounds ridiculous that an adult has anxiety issues when it comes to dentists but I have had this issue for a very very long time and because of this wonderful experience I actually look forward to my next visit. I also love that their office is very clean and organized and everyone there was super nice and welcoming. Highly recommend them!

Jeremiah S. from Arcadia, CA (Source: Yelp)


Just recently started going here and my hygienist Frances is AWESOME!!!! Very nice and most importantly gentle, haven’t been to a dentist in quite awhile and she made my experience very pleasant. Definitely will be recommending to friends and family. Making appointments was easy and didn’t wait more than 15 mins to be seen the few times I’ve gone already.

Cheri C. from Monrovia, CA (Source: Yelp)


I’ve been in the care of Dr. Koo and his wonderful staff for more than 20 years. I’ve always been taken care of and treated amazingly! Our four children have had their braces done there by Dr. Abed who also is amazing. They go above and beyond to make sure you’re comfortable during all/any procedures. I highly recommend them!

Shinhae Jung (Source: Google)


I totally recommend coming here I was self-conscious about the condition of my mouth. Dr. Koo and all of his staff saw me the same day I called as I was having extreme tooth pain. Everyone was caring throughout the whole visit and they explained to me what the plan was. I never thought I would find a dentist as caring as them and I’m looking forward to check up appointment!

Lorae Fuller (Source: Google)


After calling a dozen other offices and scheduling an appointment a week later to take care of a dental emergency, I made one last call- to this office! Even though they were busy, they made time to get me in that very same day!! They not only handled my emergency quickly and efficiently- they made me feel at ease and gave me advice for other dental issues as well. Affordable, quality dentistry- I highly recommend!

John K. from Baldwin Park, CA (Source: Yelp)


Been avoiding dentists like the plague for years. Glad I decided to use my company’s dental plan to visit these guys. Came in for a “regular” check-up and was well taken care of; I was greeted with enthusiasm by the receptionist Krystal and was pushed through to my appointment way faster than I remember as a kid. Definitely considering coming back!

Neil B. from San Gabriel, CA (Source: Yelp)


As a doctor, I am very careful in choosing a medical group for my own medical/dental needs. I born with defective enamel and I’ve always had bad dental problems. When I came to see Dr Koo, I had a very loose crown covering what was left of my front six teeth and the rest where either broken or missing. I was suffering from a chronic oral infection and stomatitis. To say my teeth were a mess was a gross understatement. Unlike some of the dentists in the past, Dr Koo never made me feel guilty about the condition of my (to be honest), rotten teeth. He carefully explained what was involved and we got started. I’ve had several implant procedures and the end is in sight! Already my girlfriend is saying that I’m smiling a lot more. I feel more confident, but more importantly, my health has improved tremendously. I cannot praise Drs Koo, Nguyen and Sun enough! Thanks to Arcadia Dental Group, I have my smile and my health back!

Les R. from Duarte, CA (Source: Yelp)


Been coming here since 2010 and never have I experienced any issues. No extra wait time, no insurance issues, no extra billing. If you are clear with them, they are clear with. Call ahead and verify insurance then book your appointment. Come 10 mins prior for check in and you’ll be in and out. I’m never there more than an hour for xrays and a cleaning. I’ve had 4 wisdom teeth pulled by Dr.Koo and I felt no pain or discomfort, I didn’t even swell up. Best dentist and team in town! I recommend all family and friends and not one has had anything but a great experience.

Sir V. from Temple City, CA (Source: Yelp)


I’ve been coming here for the past six months and I’m quite pleased.  Believe it or not, I found this dentist office only after calling four others who also accepted my HMO insurance. The difference? One told me I had gum disease when I didn’t (sadly, not the first time it’s happened) while the other three informed me prior to my first appointment, insurance wouldn’t cover the entire cost of a visit and I’d have to pay between $50-$75 out of pocket.  This place?  None of that.  Not only would insurance pay for everything, but the staff would take great care of me!  In the front office, they’re friendly and helpful (they even have a sense of humor) and in back, the doctors and hygienists are cool as well.  No hidden fees, no inflated diagnoses (I’m embarrassed that this even needs to be said) and a friendly staff!  In another 6 months, I’ll be back getting my third cleaning.  I’m sold!

Renata Steiner (Source: Google)


Today was my first visit as a new patient, and so far so great. I decided to go to Best Dentistry based on a referral from a friend who recently had their wisdom teeth removed there. From the reception I received at the front desk, to working with an assistant for X-rays, and then a full exam performed by the Dentist, everyone couldn’t have been nicer. And as far as sanitary precautions against COVID are concerned, they were on top of their game. A fair amount of work needs to be done on my teeth and I suspect I’ll be in good hands.

Stef B (Source: Google)


Best dentistry is the best of the best. I’m normally not too excited for a dental appointment but Dr. Koo and the whole staff make you feel at ease. Everyone is super friendly and very professional. I’m really happy I’ve found this place. Dr. Koo actually listens too your concerns, cares and explains everything in a language you’ll understand. This is the first time in my life I’m actually not afraid to go to my next dentist appointment! Thanks Best Dentistry for an awesome experience!!

Ellie Y. from Azusa, CA (Source: Yelp)


This is not a fancy dental office when comparing with others but it doesn’t mean you have the proper equipment and technology for my need.  They never asked me for services that I have to pay out of pocket nor asked me to have treatment that surprised me like other dental office.  I’ve seen Dr. Koo and Dr. Nguyen and they are both very professional and kind to patient.  Their technicians are friendly as well. I recommend this office!

Katie A. from Arcadia, CA (Source: Yelp)


Let me start this with I normally HATE dentists. I have horrible anxiety when going. I actually chose to go out of pocket to come here rather than where my insurance sent me. I have nothing but good things to say about this office and the staff. The office is clean and they have a large waiting room with very comfortable couches and chairs. The staff is so pleasant especially krys and Maria the dentists Dr. Koo and Dr. Moreno were so nice and worked so hard to make me feel comfortable and when there was an issue at no fault of their own I got dry socket and they got me in right away to try and help me and ease the pain. I plan on doing a few more procedures and now I’m a little less anxious because I know I found such a great office!

Letty F. from Whittier, CA (Source: Yelp)


i’ll try to keep my review short, but there is so much to be praised. First off… my Family & all came here when we were young. I still remember the fish tank from way back when. As i got older i had gone to other dentists but I couldn’t tell you who they were or what made them a great experience because none of them were. Also, I needed braces.. BADLY, and no one would give them to me because they all told me that I needed oral surgery.. costing over 25k. I tried USC medical center.. same thing. Which was really disheartening because i couldn’t afford that & i hated smiling because my teeth were so embarrassing. Long story short I came back to this dentist office as I worked close by. and I knew i needed a root canal :(. As soon as i walked in the receptionist remembered me, & floored me by telling me “you like just like your mom!” .. & that made me feel Amazing let me tell you. Flash forward to my consultation with the orthodontist Dr. Abed for the first time… who was THE ONLY ONE IN MY ADULT LIFE who was able to approve braces for me.. and figure out that i didn’t need oral surgery i just had too many teeth! Not only is he an energetic breath of fresh air, he’s easy to work with & makes every visit completely enjoyable. Now THIS IS WHAT MAKES THIS PLACE EXTRAORDINARY: They were able to set me up on a payment plan that would span about 4 – 5 years WITH NO INTEREST added. I NEVER found that anywhere else.. other places would refer me to medi-credit & advise a credit line.. which i could not do & didn’t want to. So i finally started my process..Dr. Koo took care of my root canal & fillings as well as extractions. His manner of doing things is very swift & to the point, which I really appreciate because I needed a lot of work. One of the nurses went through the list of fillings I needed & suggested white bonding on my bottom fillings & silver bonding on my top fillings because no one would see the top & to keep it a little cheaper for me. My insurance didn’t cover very much, but they worked with me on the prices. Now Flash forward to 5 years later.. i look completely different, braces are almost off & I smile more than I ever thought I could. i haven’t paid a penny more than what i was originally quoted for everything. I fell behind on my payments at one point & they didn’t charge me a dime as penalty. I have referred everyone I know to this place.. i don’t live or work close by anymore but I will never go anywhere else. This place gave me my dream smile & were there to help me when I really needed a dentist & orthodontist to put my needs & budget first. I’m grateful & I highly recommend them to everyone. i’ll see if I can upload some pictures later!

Sungwoo Chunga Chung (Source: Google)


Dr. Koo is very kind and knowledgeable. I asked him a lot of questions from the get-go and he answered to all of them patiently. During the procedure, he explained to me what will happen in advance, ensuring no surprise. Overall, Dr. Koo and his staffs are genuinely caring and made my dental visit very relaxing and comfortable. Dr. Koo will be definitely my go-to dentist! * The place is currently under renovation (can’t wait to see the result!) and I heard that it will be done by end Jan 2021.

R M. from Rancho Cucamonga, CA (Source: Yelp)


I was in the market for a new dentist. I reached out to my good friend Krystal Valles to see what Dental office she worked at. She told me Arcadia Dental Group, where Dr. Koo worked and I have met before. I made my appointment and was excited to get my teeth cleaned. My experience on my first day there was excellent. The office was very clean and the rooms were comforting. I am glad Krystal referred me to Dr. Koo. I had my second appointment which was last week and it was awesome. Krystal made my appointment very smooth by taking care of my insurance and confirming my information. My dental hygienist told me teeth looked great and she polished them and I was off. I am definitely coming back for clean up.