About Us
At Pinnacle Dental Group, our mission is simple: to provide every patient with the highest level of dental care in a supportive, honest, and comfortable environment. With locations in Plainfield, Clarendon Hills, and New Lenox, we are proud to serve individuals and families across our communities with professionalism and heart.
We are passionate about dentistry — not just as a science, but as a way to change lives, build confidence, and support lifelong wellness. Every member of our team is committed to staying at the forefront of dental care through advanced training, continued education, and modern techniques. Our professionals maintain the highest levels of accreditation and constantly expand their knowledge to provide the most current and effective treatments available.
Meet Our Dentists
Meet the People Who Make Pinnacle Exceptional.
Dr. Justina Mockunas, DDS – Plainfield Dentist
Dr. Justina Mockunas is an internationally trained dentist with advanced clinical expertise and a strong commitment to excellence in modern, technology-driven dentistry. She completed the Advanced Standing Program at NYU Langone Health, earning a Certificate in Advanced Education in General Dentistry (AEGD) through an intensive two-year residency program at NYU Langone Health.
As a dedicated implantologist, Dr. Mockunas focuses on immediate dental implants, advanced oral surgery, and comprehensive full-arch rehabilitation, including All-on-X procedures. She is a graduate of the Full Arch Master Intensive Program in Advanced Implant Surgery and an ambassador of the Zero Bone Loss Concept Group, reflecting her commitment to biologically driven, long-term implant success. Dr. Mockunas has also completed advanced training in IV sedation, allowing her to provide complex surgical care in a safe, comfortable, and controlled environment.
Her advanced surgical education includes specialized training in sinus lift techniques, along with continued education through Spear Education. She has completed all levels of CEREC digital advanced dentistry courses and is a recognized mentor in digital dentistry, further strengthening her expertise in fully digital, prosthetically driven treatment planning.
Dr. Mockunas has designed and operates a fully integrated in-house digital dental laboratory, equipped with CEREC same-day crown technology, advanced 3D scanners and printers, and the iCam photogrammetry system, which captures highly accurate three-dimensional implant positioning data—ensuring precision, predictability, and superior outcomes for complex implant cases.
In addition to surgical excellence, Dr. Mockunas has a deep understanding of esthetic dentistry and cosmetic requirements, with advanced training in facial symmetry and smile design. Her approach emphasizes long-term oral health, functional stability, and natural esthetics. Known for her calm and compassionate demeanor, she is especially skilled in caring for patients with dental anxiety, creating a supportive and reassuring treatment experience.
Committed to continuous professional growth, Dr. Mockunas travels internationally to study and implement the latest evidence-based dental techniques and technologies. Outside of clinical practice, she enjoys traveling with her family, reading dental-focused literature and scientific research, and continually expanding her knowledge, always striving to deliver the highest standard of care to her patients.
Dr. Eva Coggin, DDS – Clarendon Hills Dentist
Dr. Eva Coggin brings over 25 years of experience in general dentistry and a deep passion for patient care to the Pinnacle Dental Group family. Raised in Syracuse, New York, she earned her Bachelor of Science degree from LeMoyne College in 1996 and went on to receive her Doctorate of Dental Surgery from the State University of New York–Buffalo College of Dentistry in 2000.
Following dental school, Dr. Coggin completed a comprehensive one-year residency at Kaleida Health, where she trained at both Millard Fillmore and Buffalo General Hospitals. In 2003, she relocated to the Chicago area, where she has continued to serve patients of all ages with skill, compassion, and dedication.
Dr. Coggin enjoys all aspects of general dentistry and has a special love for working with young children, helping them feel comfortable and confident during their dental visits. Her gentle and approachable demeanor makes her a favorite among patients and families alike.
Outside of the office, Dr. Coggin enjoys gardening, traveling, spending quality time with her family, and cheering on her son at his college hockey games.
Dr. Coggin is excited to be a part of the Pinnacle Dental Group family and looks forward to continuing her tradition of providing high-quality, patient-centered dental care.
Dr. Tina Chalabiani – New Lenox Dentist
Dr. Tina Chalabiani earned her dental degree from Midwestern University College of Dental Medicine–Illinois in Downers Grove. She is dedicated to providing compassionate, personalized, and high-quality dental care, with a gentle and detail-oriented approach.
Dr. Tina believes that great dentistry begins with trust and communication. She takes the time to understand each patient’s concerns, explain treatment options clearly, and create a comfortable, welcoming environment—especially for patients who may feel anxious about dental care. She is committed to continuing education and staying current with modern dental techniques and technology.
Originally from Tehran, Iran, Dr. Tina is fluent in English, Farsi, Turkish, and Azeri. Outside of dentistry, she enjoys traveling, exploring new cultures and cuisines, learning languages, spending time with family and friends, and relaxing with her dog.
Dr. Elizabeth Zaun, DDS – Plainfield Dentist
With 18 years of experience in both pediatric and general dentistry, Dr. Zaun brings a wealth of knowledge, advanced training, and a true passion for patient care. She earned her Doctor of Dental Surgery degree from the prestigious University of Iowa College of Dentistry and has spent 12 of her 18 years proudly serving the Plainfield community.
Dr. Zaun is highly trained in implant restorations, nitrous oxide sedation, pediatric dentistry, and is a certified provider of Invisalign and Botox. She is especially passionate about building comfortable, caring relationships with patients of all ages—helping children develop healthy habits and ensuring every patient feels heard, valued, and at ease.
Outside the office, Dr. Zaun enjoys spending time with her family, cheering on her two boys at their sports games, walking her dog Wilson, and relaxing with a good book.
Our Locations
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