We are proud to have served our community and Colorado for
over 50 years.

As specialists, Drs. McClain, Schallhorn and Ferguson have received extensive training in both surgical and non-surgical periodontal care and dental implant treatment. The doctors are board-certified by the American Board of Periodontology. While maintaining our focus on successful treatment outcomes for our patients, we continually strive to remain on the cutting edge of periodontal and implant therapy by attending more than 30 hours of continuing education each year. Our involvement in clinical research allows us to use the most up to date technologies and evaluate their effectiveness long term. We are proud to have served our community and Colorado for over 50 years. Dr. Robert G. Schallhorn, who is a world-renowned periodontist, originally established our office in 1972. His innovative research in periodontal regeneration has shaped the way periodontics is practiced today. We are happy to continue the legacy of improving the health and ultimately the quality of life for our patients.

Pamela K. McClain D.D.S.

Pamela K. McClain D.D.S.


Pamela K. McClain D.D.S.

Pamela K. McClain, DDS is a highly respected periodontist in the Denver metro area—for both her vast contributions to periodontal research and her cutting edge level of care. She is a licensed periodontist in Colorado and is board certified as a Diplomate of the American Board of Periodontology. Dr. McClain actively collaborates with family dentists and other dental and medical specialists and lectures on a variety of topics at interdisciplinary dental meetings and conferences locally, nationally and abroad. Dr. McClain is known internationally for her work in periodontal regeneration. She has given over 100 professional presentations throughout the United States and in Europe, South America and Asia.

In the office of Drs. McClain & Schallhorn, patients experience the benefit of not just understanding their treatment but truly owning their dental problem. Dr. McClain’s natural warmth and open approach enhance her diagnostic and clinical skills. While research and organized dentistry are important, treating patients and improving their quality of life remains her passion.

Education & Training

Dr. McClain received her B.S. in Dental Hygiene from the University of Colorado and graduated Magna Cum Laude from the University of Colorado School of Dentistry where she earned her Doctor of Dental Surgery (D.D.S.). Her post-doctoral training in periodontics was completed at the University of California in San Francisco. She then joined her father, Dr. Robert Schallhorn, in his periodontal/implant practice in 1987.

Awards & Affiliations

In recognition for her research in periodontal regeneration, Dr. McClain was awarded the first R. Earl Robinson Periodontal Regeneration Award from the American Academy of Periodontology (AAP) in 1989 (and subsequently in 2004, 2006, 2014 and 2017). From 2011-2012, she served as President of the AAP  and for the AAP Foundation in 2018. She has been active within the AAP and other organizations, including the American Dental Association, the Colorado Dental Association and the Academy of Osseointegration; Dr. McClain is the first female member to serve on the Council of the American Academy of Restorative Dentistry. In 2020 she was presented the prestigious Master Clinician Award by her peers from the AAP.

Professional Awards and Activity Highlights:

  • Graduated Magna Cum Laude (dental school)
  • Recognized by 5280: The Denver Magazine as a Top Dentist since 2008
  • Recipient: Master Clinician Award from the American Academy of Periodontology 2020
  • Inducted: International College of Dentists 2019
  • Inducted: American College of Dentists 2018
  • Recipient: 2014 Distinguished Service Award from the American Academy of Periodontology
  • Inducted: Honorary Pierre Fauchard Academy (2012)
  • Recognized as one of the “Top 25 Women in Dentistry” by Dental Products Report (9/2012)
  • Recipient: Earl Robinson Periodontal Regeneration Award from the American Academy of Periodontology 1989, 2004, 2006, 2014, 2017 for excellence in publication
  • Recipient: Special Citation Award from the American Academy of Periodontology 2021
  • American Academy of Periodontology: President, 2011-2012
  • Rocky Mountain Society of Periodontists: President, 1992
  • Academy of Restorative Dentistry: Clinic Committee, 2006-2007, 2012-2014, Council Member, 2007-2009
  • Columbine Periodontal Study Club: Board of Directors 1993 – 2011, Chair 1999-2011

Publications & Research

While maintaining a fulltime private practice, Dr. McClain has also been active in periodontal research and education. She holds or has held appointments as an Assistant Clinical Professor at the University of Colorado School of Dentistry and as a Research Professor at the University of Maryland School of Dentistry. Her research has appeared in a variety of professional publications. See her C.V. for a complete list of her ongoing participation in practice-based clinical research since 1987 and associated publications.

Current Research:

A prospective, multicenter, non-randomized, controlled clinical study utilizing non-guided vs guided surgery to immediately loaded Primetaper implants in the partially edentulous patients: Dentsply DS2021-01. Start date March 2022

A Prospective, Randomized, Controlled and Blinded Multi-Center Study to Assess the Safety and Non-Inferiority Effectiveness of Geistlich Fibro-Gide Compared with Connective Tissue Graft for Soft Tissue Volume Augmentation Around Dental Implants. 10808-122. Start date October 2018.

Most Recent Professional Publications:

McClain, PK. The use of recombinant human platelet derived growth factor -bb (rhpdgf-bb) in combination with β-tricalcium phosphate (β-tcp) and rhpdgf-bb in combination with freeze dried bone allograft (fdba) plus barrier in two separate complex infrabony defects with long term follow up. Accepted for publication Clinical Advances in Periodontics, 4 June 2022. CAP-22-0060.R1

Sanz, M, Schwarz, F, Herrera, D, McClain, P, Figuero, E, Molina, A, Monje, A, Montero, E, Pascual, A, Ramanauskaite, A, Renourd, F, Sader, R, Schiegnitz, E, Urban, I, Heitz-Mayfield, L. Importance of keratinized mucosa around dental implants: Consensus report of group 1 of the DGI/SEPA/Osteology Workshop. Clin Oral Impl Res, first published 28 June 2022. https://doi.org/10.1111/clr.13956

Velasquez, D, Guimaraes Araujo, M, Clem, D, Gunsolley, JC, Heard, RH, Janakievski, J, McClain, PK, McGuire, MK, Misch, C, Nevins, ML, Pickering, S, Pope, B, Richardson, C, Santarelli, G, Scheyer, ET, Schallhorn, R and Toback, G. A Prospective, Randomized, Controlled, Multi-Center Evaluation of Extraction Socket Management Comparing a Wound Dressing and a Soft Tissue Substitute. Int J Periodontics Restorative Dent (online) accepted 20 March 2022.

Schallhorn, RA, McClain, PK, Benhamou, V, Doobrow, J, Grandin, HM, Kasaj, A. Application of enamel matrix derivative in conjunction with non-surgical therapy for treatment of moderate to severe periodontitis: A twelve-month, randomized prospective, multi-center study. J Periodontol 2021;92:619-628.

Cochran DL, Oh T, Mills MP, McClain PK, Schallhorn R, McGuire MK, Scheyer TE, Giannobile WV, Reddy MS, Abou ARaj RV, Vassilopoulos PJ, Genco RG, Geurs NC, Takemura A. A Randomized Clinical Trial Evaluating rh-bFGF/B-TCP in Periodontal Defects. J Dent Research 2016, Vol. 95(5) 523-530.


View Full CV:https://periocolorado.com/wp-content/uploads/2022/02/McClain-CV-2022.doc

Rachel A. Schallhorn D.D.S., M.S.

Rachel A. Schallhorn D.D.S., M.S.


Rachel A. Schallhorn D.D.S., M.S.

Dr. Rachel Schallhorn, a Diplomate of the American Board of Periodontology (board‐certified periodontist), has been in practice at the office of Drs. McClain & Schallhorn since 2009. She is experienced and proficient in diagnosis and treatment of periodontal disease, bone grafting procedures, dental implant placement, and a range of cosmetic and corrective periodontal procedures. As a third‐generation dental practitioner, Dr. Schallhorn brings a contemporary approach to the “chair‐side manner” and welcomes open dialog with her patients about the diversity of treatments available today.

In addition to practicing periodontics, Dr. Schallhorn enjoys many of the outdoor activities our beautiful state of Colorado has to offer, including skiing, biking and climbing 14ers with her husband.  She is also an avid runner and enjoys running marathons and half-marathons throughout the year.

Education & Training

Dr. Schallhorn graduated Suma Cum Laude from Capital University in Columbus, Ohio with a Bachelor of Arts degree in biology and a minor in chemistry. Following her undergraduate education, she attended the University of Michigan School of Dentistry, earning her Doctor of Dental Surgery degree.  Dr. Schallhorn then pursued specialty training in periodontics at the University of Texas Health Science Center in San Antonio. While in her periodontics residency she received comprehensive training in periodontal and implant surgery.  In addition, Dr. Schallhorn completed a Masters of Biomedical Science in combination with her periodontics specialty degree. Click here to view Dr. Schallhorn’s complete C.V.

Awards & Affiliations

Dr. Schallhorn is the recipient of both academic and professional honors in the field of periodontology.

  • Recipient: R. Earl Robinson Periodontal Regeneration Award from the American Academy of Periodontology 2017, for excellence in publication
  • Rocky Mountain Society of Periodontists, President, 2013
  • 5280 Top Periodontist, 2013 to present
  • Kramer Scholar Award for Excellence, finalist, 2009
  • Balint Orban Prize, clinical research finalist, 2009
  • John F. Prichard Prize finalist, honorable mention, 2009
  • Omicron Kappa Upsilon
  • AAP Dental Student Award for Achievement in Periodontology, 2006
  • Michigan Periodontal Alumni Award, 2004

In addition to participating in research, Dr. Schallhorn is an active member of the American Academy of Periodontology and the Rocky Mountain Society of Periodontists as well as the American (ADA) and Colorado Dental Associations and the Metropolitan Denver Dental Society.

Current Research:

Straumann Emdogain Application in Conjunction with Minimally Invasive Surgical Technique for Periodontal Disease Treatment: a Split-Mouth Design Study.  CRO 01/15 (2015-2017)

Recent Research & Publications:

Cochran DL, Oh T, Mills MP, McClain PK, Schallhorn R, McGuire MK, Scheyer TE, Giannobile WV, Reddy MS, Abou Araj RV, Vassilopoulos PJ, Genco RG, Geurs NC, Takemura A.  A randomized Clinical Trial Evaluating rh-bFGF/B-TCP in Periodontal Defects.  J Dent Research 2016; vol. 95(5):523-530.

Schallhorn RA. Understanding the Inter-relationship Between Periodontitis and Diabetes: Current Evidence and Clinical Implications. Compend Contin Educ Dent. 2016 Jun;37(6):368-370.

Schallhorn RA, McClain PK, Charles A. Clem D, Newman MG.  Evaluation of a Porcine Collagen Matrix to Augment Keratrinized Tissue and Increase Soft tissue Thickness Around Existing Dental Implants.  Int J Periodontics and Rest Dent 2015;35:99-103.

Schallhorn RA, McClain PK. Periodontal Regeneration: Management of Periodontal Osseous Defects by the Periodontist-Dental Hygienist Team. J Evid Based Dent Pract. 2014 Jun;14 Suppl:42-52.e1.doi: 10.1016/j.jebdp.2014.04.008.

Schallhorn RA.  Diagnosis and Management of Vertical Bony Defects in Periodontal Disease. Gen Dent. 2012 Jul-Aug;60(4):290-7.

View Full CV:

Brittney N. Ferguson, D.D.S., M.S.

Brittney N. Ferguson, D.D.S., M.S.

Dr. Brittney Ferguson is a Diplomate of the American Board of Periodontology (board certified in periodontics and implant surgery). Dr. Ferguson grew up in the military and has lived in several states across the US as well as in Germany. Following her periodontal residency, she moved to Denver to make Colorado her permanent home. Dr. Ferguson has extensive knowledge and training in the scope of periodontics, periodontal plastic surgery, dental implants, and oral implantology related surgeries. She prides herself on helping patients understand periodontal disease and its effect on the oral cavity and overall systemic health. Dr. Ferguson has given presentations both on a local and national level and is involved in periodontal education and clinical research.

Education & Training

Dr. Ferguson graduated Magna Cum Laude and Phi Beta Kappa from Texas Tech University with a dual Bachelor of Science in Biology and Bachelor of Arts in Psychology. She continued her education in Texas and received her Doctorate in Dental Surgery (DDS) at the University of Texas School of Dentistry at Houston. She completed a three-year periodontal residency program and received her Master of Science in Dentistry (MSD) in Oral Biology and Certificate in Periodontics from the University of Texas School of Dentistry at Houston.

Awards & Affiliations

  • Straumann Annual Meeting Scholarship, 2020
  • Balint Orban Prize, Clinical Research winner, 2019
  • AAP In-Service Award Scholarship, Highest Overall Exam Score, 2018
  • Caffesse Scholarship, 2017, 2018
  • Quintessence Award for Clinical Achievement in Periodontics, 2016
  • Clinical Specialty Honors Clerkship – Periodontics, 2015

In addition to participating in research, Dr. Ferguson is an active member of the American Dental Association (ADA), American Academy of Periodontology (AAP), Colorado Dental Association (CDA), and Metropolitan Denver Dental Society (MDDS).

Current Research:
Dentsply DS2021-01: prospective, multicenter, non-randomized, controlled clinical study utilizing non-guided vs guided surgery to immediately loaded primetaper implants in partially edentulous patients

Recent Research & Publications:
1. Ferguson B, Bokka NR, Maddipati KR, Ayilavarapu S, Weltman R, Zhu L, Chen W, Zheng WJ, Angelov N, Van Dyke TE, Lee C-T. Distinct profiles of specialized pro-resolving lipid mediators and corresponding receptor gene expression in periodontal inflammation. Frontiers in Immunology 2020, 11:1307.

2. Soldatos N, Al Ramli R, Nelson-Rabe L, Ferguson B, Soldatos K, Weltman R. Vertical ridge augmentation (VRA) with the use of a cross-linked resorbable membrane, tenting screws, and a combination grafting technique: a report of three cases. Quintessence International 2020(Oct):2-13.

3. Lee C-T, Li R, Zhu L, Tribble GD, Zheng WJ, Ferguson B, Maddipati KR, Angelov N, Van Dyke TE. Subgingival microbiome and specialized pro-resolving lipid mediator pathway profiles are correlated in periodontal inflammation. Frontiers in Immunology 2021; 12:691216.

View CV:https://periocolorado.com/wp-content/uploads/2022/02/FERGUSON-CV-2022-new.docx

Our Staff

We consistently receive positive feedback from patients who truly enjoy and appreciate our team members. We take pride in having long-term relationships with our patients. Many have been coming to see our doctors since 1972 for their periodontal/implant needs.

Our dental hygienists are extremely well educated and experienced in the field of periodontics. They are key providers of active and preventive periodontal therapy. Our hygienists attend continuing education programs numerous times per year and stay abreast of the latest techniques and technologies to help our patients achieve and maintain good oral health. Dental hygienists are your key to long-term periodontal health. They are excellent communicators and go the extra mile to ensure successful therapeutic outcomes, which is the heart of prevention.

We are fortunate to have exceptional dental assistants with years of chair-side experience. They not only assure that our time together in treatment goes smoothly, but are involved as oral hygiene educators, providing pre- and post-surgical care and for much of the behind the scenes support, such as sterilization, cleanliness, and infection control.

You will find the front office staff extremely professional and capable. Their experience scheduling appointments, managing phone calls and helping with insurance assures that your visits are pleasant and enjoyable.


Adding an Extra Layer of Protection

We feel it is critical to grow and learn and as a result continuing education is a key part of our office routine. In addition, we have annual training for OSHA where infection control systems are reviewed for added safety and comfort. Our entire staff is trained regularly on emergency procedures and maintains certification in CPR.