Meet Our Doctors

Aziz Rasulov

Dr.Aziz Rasulov is experienced, a skilled and caring dentist who loves working with kids and enjoys working with adults. He provides high-quality dental care in a State-of-the-Art, modern, comfortable dental practice.

Dr. Aziz Rasulov has been recognized as AMERICA'S TOP DENTISTS in 2009 - 2015, 2018 by consumers' research council.

Dr. Aziz is a member of American Dental Association, Colorado Dental Association, Metro Denver Dental Society, American Academy of Pediatric Dentistry as a general dentist affiliate and American Academy of Facial Esthetics.

Dr.Aziz Rasulov holds dual dental degree: graduated with Honors from former Soviet Union State Tajikistan (Tajik State Medical University, Dental Department) in 1995 and in the United States he graduated from Advanced Standing D.D.S. Program at New York University, College of Dentistry in 2003 as a top 15% of the class. He was admitted to the OKU Dental Honor Society. In 2003-2004 Dr. Aziz Rasulov attended valuable postdoctoral training at VAMC in Denver, Colorado and earned Certificate in General Practice Residency. He takes numerous continuing education courses and is trilingual (English-Russian-Tajik).

Besides dentistry Dr.Aziz likes to travel, play sports and spend quality family time. He is married and has three children: 12 year old boy, 10 year old boy and a 3 year old daughter.

Douglas J.Mills

Dr. Mills, a West Virginia native, received his undergraduate education from West Virginia University, as well as completing dental school at WVU School of Dentistry, where he earned his Doctor of Dental Surgery degree in 1982.

He spent 30 years in his solo, private practice in his hometown of Elizabeth, WV, where he provided all aspects of general dentistry.

Upon deciding to close his private practice, Dr. Mills transitioned into the role as an Associate Dentist for a group practice near Parkersburg, WV. In 2014 he and his wife Dawna decided to relocate to Denver, Colorado area where he continued to work as an Associate Dentist.

Dr. Mills believes in delivering quality care for all patients in a professional and personable manner. Staying abreast of the latest technology and patient treatment in the Dental field is also a top priority. Dr. Mills is a member of the ADA, CDA and MDDS.

When not practicing dentistry, Dr. Mills enjoys exploring Colorado with his wife and dog Gizmo. Together they have a blended family of five grown children all of which live in different states. A sports fan and an avid follower of his Alma Mater’s college football and basketball teams, Dr. Mills also likes to play golf and listen to classic rock music.

Dr. Pria Chang

Being a dentist is a dream come true and I'm thankful to be able to do what I love, every day! It’s an honor to work with each and every patient who entrusts me with their care.

I completed my undergraduate degree at James Madison University, in Harrisonburg, VA and, following graduation, worked in the genetic support lab at Howard Hughes Medical Institute for several years. I then enrolled in dental school and earned my Doctor of Dental Surgery degree (DDS) from Virginia Commonwealth University. During my time as a dental student, I excelled in endodontics and was selected to perform complicated root canal cases for not only my patients, but also my classmate’s patients. This was an honor I carry with me to this day!

Following graduation, I attended a General Practice Residency at Hunter Holmes McGuire Veterans Hospital, where I was able to advance my knowledge and skill set in the field of prosthodontics, periodontics and oral surgery. During the first year of the COVID pandemic, I remained in the hospital and had the honor of performing emergency treatment such as root canals and extractions, for the veterans who were most vulnerable and required care. Following this I worked for a family practice in Fredericksburg, Virginia until relocating to Colorado.

In my free time I enjoy skiing and hiking with my husband, sewing clothes and accents for my home, and reading books outside. I am very excited to be working at Cozy Dental Kids & Family, and look forward to meeting all of you!

Dr. G. Frederick (“Fred”) Siersma D.D.S., M.S.

Dr. Siersma is experienced and skilled Orthodontist is a Denver native, spent his early years just downwind of Lowry Air Force base. While still in elementary school he moved to Littleton and was graduated from Littleton High School.

Because at the time, there was no dental school in Colorado, Dr. Siersma attended the University of Michigan, the alma mater of both his parents. He received his M.S. and his D.S.S. degrees there. From there he went to Loyola University in Chicago where he received an M.S. in Oral Biology and his Certificate of Specialty in Orthodontics.

Following graduation from his residency, Dr. Siersma entered the United States Air Force and was stationed at Elmendorf A.F.B. in Anchorage, Alaska as base orthodontist. Because there was no orthodontist at Eielson A.F.B. near Fairbanks, he spent a week every month there. 

Dr. Siersma’s professional memberships include the American Dental Association, Colorado Dental Association, Metropolitan Denver Dental Society, American Association of Orthodontists, Rocky Mountain Society of Orthodontists and the Colorado Orthodontic Association. He has also been an Associate Clinical Professor of Orthodontists at the University of Colorado School of Dental Medicine since the program’s beginning.

Away from the office, Dr. Siersma has been an avid bicyclist since the late ‘70’s. He is still an active member of the Denver Bicycle Touring Club. He also loves hiking and has been a member of the Colorado Mountain Club since 2008. 

Dr. Paul Raines

Dr. Raines discovered his passion for dentistry when he was 17 years old. He was offered a job in his orthodontist’s office when he graduated high school and there was no turning back. The next 10 years he spent working in orthodontics developing an appreciation for dental esthetics, careful attention to detail, and an extensive knowledge of the Invisalign clear aligner system.

Dr. Raines grew up in a military family, spending most of his childhood in Japan and Alaska. He completed his bachelor’s degree in biological sciences from the University of Alaska Anchorage. Dr. Raines attended dental school at the University of Colorado School of Dental Medicine where he obtained his doctorate of dental surgery degree.

He is married to his high-school sweetheart Heather and they have two wonderful children named Liam and Leighton. When he is not in the office you can usually catch him out hiking, camping, training for a half-marathon, coaching his son’s football team or hanging out at the pool with his family and friends.

Dr. Cassio Castro

Dr. Cassio Castro is originally from Brazil. He graduated from Anapolis Dental School in 2003 and practiced as a General Dentist in Brazil. Dr. Castro relocated to the United States where he attended the University of Pennsylvania, School of Dental Medicine, and graduated in 2011 with a DMD degree. During his academic years, Dr. Castro's dedication, professionalism, attitude, skills, and passion were consistently praised by both patients and faculty. For that reason, he was referred to be a part of the Medically Complex Honors Program, Clinical Honors Program, and Teaching Coordinator for the Pre-Clinical PASS Program - Class of 2013.

Dr. Castro is an outstanding Dentist who consistently puts the needs of his patients ahead of his own. He operates in a methodical and non hurried manner, and is a stickler for the minute details. One can say that he is a bit of a perfectionist. When it comes to a patients Smile and Overall Satisfaction, Dr. Castro will not rest until he is satisfied with the work that has been performed. Dr. Castro chose to become a dentist because he saw the impact that he can have in a patients life.

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14025 East Exposition Avenue, Aurora, CO, 80012, USA

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