About Us | 4M Dental Implant Center

The Doctors at 4M Dental

With thousands of implants placed, the doctors at 4M Dental Implant Center have successfully taken on some of the most complex cases. Dr. Sean is a leader and educator in the field of dental implants – at the forefront of what’s happening in the industry – and passes his knowledge on to his associates. Through the 4M Institute (located in our Long Beach facility), Dr. Sean teaches the art and science of the All-on-X solution to dentists from around the world. His years of experience and wealth of knowledge enable us to educate our patients on their best options and what to expect.
Love Your Smile Again at 4M Dental Implants!
Dental implant center where professionals provide full mouth dental implants

Meet Our Doctors

Choosing to invest in dental implants is a big decision. There are many dentists who say they specialize in full-arch dental implants. So what makes us any different? Quite a lot, actually.

A male medical professional specializing in whole mouth dental implants, wearing a blue scrub suit, sits smiling in a bright clinical laboratory setting.

Sean Mohtashami, DDS

Dr. Sean Mohtashami is a distinguished leader in dental implantology, renowned for his innovative approach to full-mouth restoration and cosmetic dentistry. As the founder of 4M Dental Implant Centers and the 4M Institute, Dr. Mohtashami has dedicated over two decades to transforming smiles and advancing dental education.

After earning his Doctor of Dental Surgery degree from the University of Southern California School of Dentistry in 1996, Dr. Mohtashami pursued advanced training at the Las Vegas Institute for Advanced Dental Studies (LVI), where he specialized in comprehensive aesthetics, neuromuscular coronoplasty, and functional occlusion. His commitment to excellence led him to achieve a Certificate of Excellence from the DITC implant dentistry school, further solidifying his expertise in implantology.

In 1998, Dr. Mohtashami established his first practice, All Bright Dental, in Las Vegas, Nevada. Recognizing a need for specialized implant solutions, he became one of the first dentists in the Las Vegas Valley to offer the All-on-4 dental implant procedure. His success in this area led to the expansion of his practice into multiple locations across California and Nevada.

In 2018, Dr. Mohtashami founded the 4M Institute in Long Beach, California, a state-of-the-art training facility designed to educate dentists worldwide in advanced implant techniques, as well as practice management, marketing, and leadership. Through hands-on courses and mentorship, he has empowered countless dental professionals to elevate their practices and deliver exceptional patient care.

Beyond his clinical and educational endeavors, Dr. Mohtashami is also an author and media personality. His book, “There’s No Standing Still,” offers insights into building a state-of-the-art dental practice by focusing on ongoing education, growth, team development, and patient satisfaction.

Dr. Mohtashami’s dedication to excellence and innovation has earned him recognition as a Top 100 Implant Surgeon worldwide. His passion for dentistry, combined with his commitment to education and patient care, continues to inspire both colleagues and patients alike.

Samira Houshiar, DDS (NB)

Dr. Samira Houshiar graduated UCI with honors receiving her bachelor’s degree in biology in 1997. In 2001 she received her Doctoral in Dental Surgery (DDS) from UCLA school of dentistry and since she has continued her education in many different dental subspecialty programs.

Soon after receiving her DDS, she continued her education in cosmetic dentistry at LVI (Las Vegas Institute) and graduated in 2003. While practicing cosmetic and general dentistry, she completed her certification in Occlusion, Neuromuscular, and TMJ treatment concurrently. To bring more comfort to her most anxious patients, Dr. Samira completed the training necessary to be certified in Conscious Sedation (2004) and I.V. Sedation (2020).

Since completing her assistant fellowship in Implantology back in 2009, Dr. Samira has dedicated her career to full mouth reconstruction and designing beautiful and functional smiles for her patients. She is currently practicing at 4M Dental Implant Center at Newport Beach location. Dr. Samira Houshiar is a firm believer that the road to quality has no finish line. She is dedicated to staying at the cutting edge of technology and all dentistry has to offer. She is determined to change lives one smile at a time.

A professional woman with blonde hair, wearing a black shirt with a logo, smiling and standing with her arms crossed in a modern office environment.

Athena Goodarzi, MS, DDS (LB)

Dr. Athena Goodarzi is a recognized leader in full arch dentistry, known for her exceptional skill in full mouth rehabilitation and advanced implantology, with a special focus on the All-on-X solution. Her clinical expertise spans complex cases, including severe bone loss and zygomatic and pterygoid implants, where her meticulous approach consistently delivers life-changing results for patients.

Dr. Athena graduated from The University at Buffalo School of Dental Medicine, one of the top dental programs in the nation. She completed her residency at the College of Physicians & Surgeons of Columbia University, New York City.

Dr. Athena’s skills in blending art with function are unique, but her attention to detail and gentle approach to dentistry are what stand out the most. Dr. Athena’s ability to connect with her patients, create relationships, and design the best treatment possible makes her the perfect addition to our team.

Beyond her practice, Dr. Athena is deeply committed to education and mentorship. As the lead educator at the 4M Institute and a Key Opinion Leader for the Straumann Group, she trains dental professionals across the country and around the world in the art and science of full arch implant solution. She made history as the first female dentist to teach full arch implant solutions at ORCAA (Operation Re-dentulate Central America Association) in collaboration with Universidad Francisco Marroquín in Guatemala and continues to mentor clinicians through hands-on courses and leadership development—bridging innovation with compassionate care at every level.

Dr. Athena has profoundly affected the smiles and lives of many of our patients globally and would love to do that for you, too.

Philip Konopa, DDS (LB)

Dr. Phil received his Doctor of Dental Surgery degree from the University of Washington, then proceeded to complete a general practice residency at UCLA. His passion for aesthetics and critical eye for detail enable him to consistently deliver outstanding results to patients.

Dr. Phil’s focus is on full mouth restoration and reconstructive dentistry, skillfully utilizing his years of experience in this space to tailor results that harmonize patient’s desires and their unique facial features. He primarily achieves his successful results by providing patients with mockups before starting treatment and working with experienced labs. He also offers conscious sedation to ensure patient comfort during transformative procedures.

In addition to his passion for dental aesthetics, Dr. Phil enjoys traveling, golfing, and gardening, and lives in Huntington Beach with his wife.

Dentist in protective gear showing a female patient her teeth in a mirror during a dental examination.
A smiling man with graying hair, dressed in a blue suit and white shirt, stands in front of a bright, blurred background.

Derik Alexanians, DDS (Chief Clinical Officer)

Dr. Derik Alexanians serves as the Chief Clinical Officer of 4M Dental Implant Centers. With a strong commitment to innovation, education, and patient centered care, he has played a key role in the growth and development of 4M into one of the most trusted implant centers in the country.

He leads clinical strategy, mentors providers, and ensures that every aspect of care reflects 4M’s high standards, from surgical execution to the overall patient experience. With over 20 years of clinical experience, Dr. Alexanians combines technical expertise with a compassionate approach to help patients restore their health, confidence, and quality of life.

Kostika Polena, DDS

“I believe everyone deserves the benefit of a happy and healthy smile. As your dental provider, I am committed to helping you overcome any barriers preventing you from receiving the best oral health care possible.”

Early on Dr. Polena discovered a love and talent for art and later for science, graduating from UNLV with a degree in Biochemistry. Dentistry has turned out to be an ideal blend of his two passions. For Dr. Polena, dentistry has been a tremendously rewarding experience thus far and looks forward to a long career and enduring relationships with his patients.

Dr. Polena’s patients will quickly recognize the quality and the personal dental care he delivers. Through effective treatment plan presentation and patient communication, he has been able to consistently exceed patient expectations.

Dr. Polena excels in dental implants, extractions, dentures/partials, crowns and bridges, laser dentistry, Invisalign, and more.

An image of Dr. Polena at 4M Dental Implant Center in Las Vegas
Professional man with dark hair and beard, wearing a gray blazer and white shirt, smiling in an office environment.

Tirakhsh Emadi, DDS, MS, DABOI, FAO (VA, AH, MU)

Dr. Tirakhsh Emadi is a highly skilled prosthodontist and implant specialist practicing in Los Angeles, California. He earned his Doctor of Dental Surgery (DDS) degree in 2009 from Tehran Azad University of Dentistry in Iran and practiced general dentistry for several years before pursuing advanced specialization.

Dr. Emadi furthered his expertise by completing a specialty certificate in Prosthodontics and a Master of Science in Dentistry at Nova Southeastern University, where he served as Chief Resident and received the prestigious Dental Implant Surgery Award. His advanced training also includes the Maxicourse by the American Academy of Implant Dentistry (AAID), where he honed his skills in digital dentistry and complex implant procedures, including zygomatic and pterygoid implants.

He is a diplomate and board-certified by the American Board of Oral Implantology/Implant Dentistry (ABOI/ID), one of the highest credentials in implant dentistry, underscoring his dedication to clinical excellence. In addition, Dr. Emadi is a Fellow of the Academy of Osseointegration—an honor achieved by only 118 dentists worldwide.

Passionate about both patient care and education, Dr. Emadi actively teaches other dentists on a range of topics, including single implants, overdentures, full-mouth dental implant rehabilitation, zygomatic and pterygoid implants, and digital workflows. He has delivered over 25 presentations at national and international dental conferences, earning accolades such as first place at the 70th AAID Annual

Conference and second place at the 29th Academy of Osseointegration Annual Meeting. His scholarly work includes several publications in peer-reviewed scientific journals.

Dr. Emadi maintains active memberships in professional organizations such as the American Dental Association (ADA), California Dental Association (CDA), Los Angeles Dental Society (LADS), American Academy of Implant Dentistry (AAID), and the Academy of Osseointegration (AO). He also serves on several committees within the Academy of Osseointegration, including the Young Clinician and E-Poster Committees, and contributes as an editor for the Academy News Committee.

With a commitment to innovation, excellence, and education, Dr. Emadi continues to shape the future of prosthodontics and implant dentistry both in his clinical practice and beyond.

1. Implant Rehabilitation After a Partial Resection of the Mandible Resulting from Submandibular Gland Malignancy-A Case Report. J Oral Implantol. 1 June 2022; 48 (3): 220–225.

2. Full Mouth Rehabilitation Using Dental Implants with Immediate Loading in a Systemic Sclerosis Patient; A Case Report. Inside Dentistry. 2021 July; 17(7).

3. Immediate Implant Placement and Provisionalization in the Esthetic Zone Using Flapless Technique. Compendium of Continuing Education in Dentistry. 2021 July/Aug;7(42).

4. Oral rehabilitation of a patient with ankylosing spondylitis and orofacial pain: A case report. Surgery and Rehabilitation. 2017 Sep;1(3) 1-5.

5. Effect of Surface Treatment on Retention of Prefabricated Glass-fiber Posts. Journal of Universal Surgery. 2016 Feb;3(5).

6. The Effects of Two Attachment Types on the Stresses Introduced to the Mandibular Residual Ridge; A 3D Finite Element Analysis. Quintessence International. 2013 Sep;44(8):585-590.

7. Stress Introduced by Two Attachment Types in Four Implant-retained Overdenture; A 3D FEA Study. Research in Dentistry. 2009 Jul;6(2):9-17.

Kamran Pakdamanian, DMD (RS + AH)

Dr. Kamran Pakdamanian is a dedicated clinician known for his thoughtful, patient-centered approach and growing expertise in implantology, Full Mouth Rehabilitation with All-on-X solutions, and I.V. sedation. He combines clinical precision with genuine compassion, offering comprehensive care that prioritizes both long-term outcomes and patient comfort.

Dr. Pakdamanian earned his Doctor of Dental Medicine (DMD) from Western University of Health Sciences, where he developed a strong foundation in comprehensive care and minimally invasive dentistry. He has since pursued advanced training in implantology, with a particular emphasis on Full Mouth Rehabilitation using All-on-X solutions, allowing him to restore both function and esthetics for patients with failing or missing dentition.

In addition to his clinical expertise, Dr. Pakdamanian is certified in intravenous (I.V.) sedation, enabling him to manage dental anxiety and perform advanced procedures in a safe, controlled, and comfortable environment. His dual expertise in sedation and implantology allows him to streamline complex treatments while prioritizing patient well-being throughout the process.

Widely recognized for his calm and attentive chairside manner, Dr. Pakdamanian builds strong rapport with his patients, helping them feel heard, understood, and at ease throughout their treatment. His ability to combine technical excellence with compassionate care has earned the trust and appreciation of patients and colleagues alike.

He is a member of the American Dental Association, the California Dental Association, and the Tri-County Dental Association, and remains committed to professional development through ongoing education and clinical training

Kal Eissa, DDS (MU)

Dr. Kal Eissa received his High School Diploma from Cambridge, UK, his dental degree from University of Cairo, and his Continuing Education from the University of Minnesota. Dentistry is a profession that allowed Dr. Eissa to positively impact people’s lives almost immediately. “It’s a great feeling!” says Dr. Eissa. “Few professions can give you this privilege. I’m lucky to be in one.”

Dr. Kal Eissa earned his bachelor’s degree in Dental Medicine and surgery in 1999.

He attained his Fellowship in Dental Implants by the American Academy of Implant Prosthodontics in 2015. He achieved his certificate from the American Board of Aesthetic Medicine in 2016.

He is certified in IV sedation by the dental board of California.

His twenty-five years of experience in dentistry allows him to deliver the highest standard of care in a pain-free way.

His motto is “Always keep it simple”.

Dr. Navid Torabian (VA)

Dr. Navid Torabian is a highly skilled, surgically trained dentist specializing in dental implants and advanced full mouth reconstruction. A Sacramento native, Dr. Torabian’s journey to dentistry has been as dynamic as it is inspiring. He graduated with a degree in Biological Sciences from the University of California, Irvine, where he was a standout athlete, playing Division I soccer. Shortly after, he pursued his childhood dream and played professional soccer in Germany, refining his discipline, teamwork, and leadership on the field.

Upon returning to the U.S., Dr. Torabian earned his Doctor of Dental Surgery (DDS) degree, graduating summa cum laude from the University of the Pacific Arthur A. Dugoni School of Dentistry in 2016. Driven to deepen his expertise in full mouth implant reconstruction, he completed a prestigious surgical residency program focused on dental implants and advanced oral surgery at the VA Medical Center in Long Beach, CA.

With thousands of hours of continuing education and hands-on training, Dr. Torabian’s practice is now dedicated to providing the highest standard of care in dental implants, focusing on the latest techniques in restoration and full mouth reconstruction. His commitment to excellence, combined with his passion for staying at the forefront of dental innovations, ensures that each of his patients receives personalized, cutting-edge treatment.

Dr. Torabian is a member of the American Dental Association, Academy of General Dentistry, American Academy of Cosmetic Dentistry, American Academy of Implant Dentistry, International Congress of Oral Implantology, and American Academy of Facial Esthetics. He remains committed to making a positive, lasting impact on his patients’ oral health and quality of life.

dr denning in the san diego office

Dr. Andrew Denning (SD)

Dr. Andrew Denning earned his Doctorate of Dental Surgery (DDS) from the University of Tennessee Health Science Center. After practicing for several years in Tennessee and Mississippi, he moved with his partner to San Diego where they currently reside. For his entire career, Dr. Denning has pursued advanced training in full mouth rehabilitation and implant placement. He has a passion for working with patients with complex oral health challenges in order to restore them to healthy, functional, and beautiful smiles. Dr. Denning loves being able to put patients at ease before their appointments and delivering high quality work in a relaxing environment.

Samuel Sauza Jr, DDS

After receiving his Doctor of Dental Surgery degree from Loma Linda University, Dr. Samuel Sauza entered one of the most prestigious postgraduate programs for residency, training, and research in the field of oral implantology, where he served for 3 years. Loma Linda University is one of the few formal institutions offering degrees in implant dentistry, where its full time residents learn both surgical and prosthodontic principles in-depth, allowing for whole patient care. 

Having achieved his specialty training certificate in Oral Implantology, Dr. Sauza has continued to develop extensive post-graduate practical experience in the practice of oral-dentoalveolar surgery, the placement of conventional and advanced remote anchorage implants, bone grafting & tissue regeneration techniques, and the design of implant prosthetics utilized in partial & full mouth reconstruction. Dr. Sauza has treated a wide variety of patients and conditions over the years, with the majority of his work being focused on full arch implant dentistry and resolving complex cases encountered by his colleagues throughout California. 

Utilizing his training on the most state-of-the-art techniques available, Dr. Sauza is able to provide his patients with simple, efficient, and comprehensive solutions to treat their needs. When under Dr. Sauza’s care, you can expect to experience a palpable level of empathy, understanding, and attention to detail that is often hard to find.

dr sauza

Dr. Will Abdelmalik (LV)

For Dr. Will, dentistry has never been just a career, it is a calling. With a unique blend of dental expertise, artistry, and craftsmanship, he finds deep fulfillment in restoring function, relieving pain, and giving patients the smile of their dreams. “Dentistry has been a blessing, giving me the ability to make a real impact on my patients’ lives,” he says. “It is incredibly rewarding to see someone walk out healthier and more confident than when they came in.”

Dr. Will is committed to lifelong learning and is constantly refining his skills through advanced surgical training and continuing education. He has completed the prestigious AAID Las Vegas MaxiCourse and is currently an Associate Fellow with the American Academy of Implant Dentistry, aspiring to one day become a Diplomate. His clinical focus includes full-arch rehabilitation, implantology, oral surgery, and cosmetic smile design, utilizing the latest digital and biomimetic techniques.

He also shares his knowledge as a mentor and hands-on instructor with the BAARD Institute, where he teaches advanced adhesive and restorative dentistry to fellow clinicians.

Outside of the operatory, Dr. Will enjoys taking his Jeep on outdoor adventures with his dog, Cleo, and dreams of visiting every U.S. national park. At home, you will often find him restoring his mid-century home, a testament to his passion for craftsmanship and detail.

Dr. Kevin Clifford, DDS (PD)

Dr. Kevin Clifford brings a deep-rooted passion for dentistry to 4M Dental, having grown up in a multigenerational dental family in Agoura Hills, California. His grandfather was a respected dentist and educator who taught at Loma Linda University for 17 years. His mother worked as a dedicated dental hygienist for over 30 years in Los Angeles, and his brother also practices dentistry—making oral health and patient care a true family legacy.

A proud graduate of the Herman Ostrow School of Dentistry at USC in 2016, Dr. Clifford has since developed extensive experience in full mouth rehabilitation. Whether through advanced implant dentistry or custom crown restorations, he is known for helping patients regain confidence through healthier, longer-lasting smiles. His certification in IV sedation allows him to safely and comfortably provide anxiety-free dental care, while also expanding the range of procedures he can perform.

Fluent in English, Portuguese, and Spanish, Dr. Clifford values strong communication and connection with every patient. He believes in a personalized, compassionate approach and takes pride in making people feel at ease from their very first visit.

Outside the office, Dr. Clifford enjoys spending time with his wife and their dog, traveling the world to explore local cultures and cuisines, and staying active through sports and water activities. Whether he’s cheering on his favorite team or paddleboarding in the sun, he brings the same energy and positivity to everything he does.

Three professionals, two men and one woman, smiling and standing together in an office with a sign that reads “dental implants” in the background.