Our Doctors

John Borja DDS

Meet Dr. John, a seasoned dentist with over 37 years of experience, passionately providing care to his favorite people. Born and raised in Guam, Dr. John pursued his undergraduate and dental education at Marquette.

Dentistry runs in the family, with Dr. John's father serving as a dental lab technician. He completed his dental journey at Marquette Dental School in 1986 and has since been dedicated to helping everyone achieve better oral health through education, treatment, and setting an example. Dr. John's commitment extends beyond the office, with mission trips to Guatemala in 2010 and 2015, as well as participation in Mission of Mercy from 2013 to 2017.

Beyond his professional life, Dr. John engages in Ironman competitions, biathlons, cross-country skiing, playing the piano, racing sports cars, fishing, hunting, and extensive travel. He also enjoys spending time with friends and family.

Anna Minnema DDS

Meet Dr. Anna, a compassionate dentist born and mostly raised in rural northwestern Wisconsin. Growing up in a healthcare-oriented family, with a physician father and a nurse mother. She identified a significant need for dentists in her rural town and decided to pursue dentistry.

Dr. Anna's journey led her to discover the joy of both the healthcare and artistic, hands-on aspects of dentistry during dental school. With a Biochemistry/Molecular Biology BS from Bethel University and a Doctorate of Dental Surgery from the University of Minnesota School of Dentistry, she has been practicing as a dentist for 14 years. Passionate about working in a rural area, Dr. Anna loves getting to know her patients, and fostering a sense of community. She values open communication and collaboration with patients, emphasizing the importance of making treatment decisions together.

Beyond her professional life, Dr. Anna enjoys hiking, camping, being a "foodie," and spending time with her family.

Megan Oldridge DMD

Meet Dr. Megan, a compassionate dentist dedicated to diagnosing and prescribing tailored treatments for patients of all ages. Originally from Chatham, Illinois, Dr. Megan's personal experience with braces as a child ignited her passion for dentistry, recognizing the transformative power of a confident smile.

Dr.Megan holds a BS in Biomedical Sciences with a minor in Spanish for the Health Professions from Marquette University and a DMD degree from Southern Illinois University School of Dental Medicine. With three years of practice in Illinois, Dr. Megan has brought her expertise to Wisconsin. Taking a comprehensive and individualized approach, Dr. Megan believes dentistry doesn't need to be scary. She ensures patients are active participants in their care, maintaining a light and fun atmosphere, even during significant procedures. 

Beyond her professional life, Dr. Megan enjoys spending time with her husband and son, indulging in reading, crocheting, and watching movies in the theater.

Our Team

Rita Sieniawski - Preferred Dental Partners

Rita

Dental Assistant

Meet Rita, a dedicated dental assistant working alongside Dr. Borja, committed to helping patients achieve better oral health and overall well-being. Hailing from Rhinelander, Wisconsin, Rita's experience with oral surgery and orthodontic treatment as a teenager sparked her curiosity and led her to a fulfilling career in dentistry.

In 2010, Rita earned her Dental Assistant technical diploma from Madison College, subsequently achieving Certified Dental Assistant status in 2012. She considers her career in dentistry a privilege, cherishing the opportunity to contribute to patients' oral health journeys.

Beyond her professional life, Rita enjoys cooking and spending quality time with her family.

Amber Nettekoven - Preferred Dental Partners

Amber

Dental Assistant

Meet  Amber, a skilled dental assistant working to fulfill patients' dental needs. Born and raised in Beaver Dam, WI, Amber's journey in dentistry has been shaped by over 20 years of on-the-job training.

While her college background isn't dental-related, Amber's dedication to continuous learning is evident as she embraces new techniques and materials every day. With a firm belief that prevention is the key to a healthy smile, she is committed to helping patients achieve optimal dental health.

Beyond her professional life, Amber finds joy in outdoor activities like kayaking, swimming, hiking, and enjoying vacations.

Kristina Pufahl - Preferred Dental Partners

Kristina

Dental Assistant

Meet Kristina, a Certified Dental Assistant dedicated to providing compassionate and high-quality patient care under the doctor's direction. Kristina's journey into the dental field began at a high school trade show, where she immediately recognized her passion for the profession. She earned her certification through DANB and Madison Area Technical College.

Kristina appreciates the dynamic nature of her role, relishing the uniqueness of each day and the opportunity to provide individualized care tailored to each patient's needs.

Beyond her professional life, Kristina enjoys taking walks and boating with her family.

Michelle Bronkhorst - Preferred Dental Partners

Michelle

Dental Assistant

Meet Michelle, a Certified Dental Assistant with a passion for dentistry that dates back to her childhood in Waupun, Wisconsin. Since the fifth grade, Michelle expressed her desire to work for a dentist, and she has been fulfilling that dream.

Michelle finds fulfillment in relieving patient discomfort and contributing to creating beautiful smiles. Michelle took part in a mission trip to Guatemala, providing dental care to individuals who walked for hours to receive treatment.

Beyond her professional life, Michelle is an avid sports enthusiast who loves watching and participating in various sporting events. She has a particular fondness for running and has completed numerous races and triathlons. Above all, Michelle cherishes spending time with her family. 

Cindy Rabata - Preferred Dental Partners

Cindy

Dental Hygienist

Meet Cindy, a dedicated dental hygienist born and raised in Beaver Dam and currently residing there. Married with a son. Cindy takes pride in, making their office an enjoyable place to work.

Passionate about helping patients achieve a healthy mouth, Cindy values continuous learning and growth. She appreciates the opportunities for ongoing education provided by the office, which is committed to delivering high-quality patient care. Cindy has volunteered for Mission of Mercy dental events in Wisconsin and Minnesota, offering free dental care to those in need.

Beyond her professional life, Cindy loves engaging in outdoor activities like biking, hiking, kayaking, and attending Badger games with friends. In the winter, she enjoys skiing in Michigan and snowshoeing.

Linda Thalacker - Preferred Dental Partners

Linda

Admin Team

Meet Linda, the welcoming first point of contact at the practice. Engaged in various aspects of the administrative role, Linda efficiently handles appointments, insurance claims, treatment plans, daily accounting, and banking. Beyond the administrative realm, she lends her skills to machine maintenance and repairs on the assistant side.

Originally from St. Paul, Minnesota, Linda spent her teenage years in Sand Creek, WI. Intrigued by the dental field. Committed to community service, Linda actively supports various organizations, including the Dodge County Toy Bank, Youth for Christ, PAVE, and more. Linda's goal is to provide patients with a caring and positive dental experience. 

Beyond her professional life, she enjoys weekend trips, biking, hiking, and exploring new areas with her husband. Family is paramount, and she relishes spending time with her four grandchildren.

Sandra

Dental Sterilization Technician

Meet Sandra. She sterilizes dental instruments using infection control protocols. Prepare the rooms for turnover for the next patient. Computer charting of patients and hygienists. Operating, sterilizing, and maintaining equipment.

She was born and raised in Wisconsin. She was always interested in the healthcare field and has twenty years of experience in the dental field.

Beyond her professional life she finds great joy in family time and vacationing! She enjoys creating, gardening, the outdoors, and finding hidden gem restaurants with her husband.

Andrew Tong DDS

Meet Dr. Andrew, a compassionate dentist dedicated to delivering patient-centered, high-quality care. Originally from San Mateo, California, Dr. Andrew also spent several years living in Taiwan, shaping his appreciation for connecting with patients from diverse backgrounds. He earned his undergraduate degree from the University of California, Davis, and his Doctor of Dental Surgery degree from Marquette University School of Dentistry.

Dr. Andrew’s passion for dentistry stems from his love of working with his hands and blending art and science to create meaningful, lasting results for his patients. He is committed to ethical treatment, clinical excellence, and lifelong learning. He has also given back through volunteer work with the Wisconsin Dental Association Mission of Mercy, providing care to underserved communities.

Outside of the office, Dr. Andrew enjoys cooking and experimenting with new recipes, exploring local coffee shops and restaurants, and staying active through outdoor activities like camping, backpacking, fishing, rock climbing, and tennis.

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