Episode 32

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Published on:

23rd Feb 2026

32: Natural Does Not Mean Consistent - Why Propolis Source Chemistry and Extraction Change Outcomes with Dr. Rob Karlinsey and Tami

What if bee propolis has struggled in oral care not because it does not work, but because formulation and variability change the outcome?

In this episode of Dental Formulator’s Playbook, Dr. Rob and co-host Tami explore why bee propolis has been “promising but niche” in oral care for years, and what might finally be changing. They break down what propolis is made of, why its resins and prenylated flavonoids matter, and how the source of propolis can change everything. Then they walk through new clinical research, including studies on Brazilian green propolis in toothpaste for gingivitis and periodontal support, what the results actually showed, and where study design still leaves unanswered questions. Along the way, they highlight a surprising history lesson on “mad honey,” and why formulation details and controls matter as much as the headline claim.

About the Hosts

Dr. Rob is an independent scientist with deep expertise in oral care formulation science, microbiology models, and product performance testing.

Tami is Dr. Rob’s co-host, helping translate complex chemistry and clinical research into practical takeaways for real-world oral care.

Key Topics Covered

  1. Why bee propolis has had limited commercial success despite years of hype
  2. What propolis is made of: resins, lipids and waxes, essential oils, pollen, and flavonoids
  3. Why propolis varies by geography and plant source, and why that matters for outcomes
  4. The purpose of propolis in the hive: structure, protection, and antibacterial defense
  5. Why oral “pathogens” are often already present, and the goal is balance, not scorched earth
  6. Gingivitis vs periodontitis: what’s reversible, what escalates, and what measurements mean
  7. Why testing on one ingredient may offer promising data, but often fails when moved into toothpaste and mouthwash systems
  8. New clinical study: Brazilian green propolis extract in toothpaste, what improved and what did not
  9. Why study duration matters, and why 2 weeks can be misleading for long-term benefit
  10. Second clinical study: periodontal therapy support, pocket depth trends, saliva pH shifts
  11. A critical nuance: when ethanol extracts are used, what is propolis vs what is ethanol effect
  12. “Mad honey” from rhododendron nectar, and why natural products can carry real risks

📲 Connect with Dr. Rob (Robert L. Karlinsey, PhD)

🌐 Website: customdentalformulations.com

Robert L. Karlinsey, PhD

Google Scholar Profile

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About the Podcast

Dental Formulator's Playbook
The Dental Formulator’s Playbook is where science meets strategy in the world of oral health innovation. Hosted by Dr. Rob Karlinsey, a seasoned dental researcher and independent formulator, this podcast is your behind-the-scenes pass to what really goes into creating cutting-edge dental products.

Whether you're a dentist, a dental brand, or just someone curious about how toothpaste, rinses, and other oral care products are developed, you'll find practical insights and real-world takeaways in every episode. Dr. Karlinsey keeps it straightforward and engaging—no fluff, just clear, thoughtful explanations based on years of experience in the lab and the industry.

This show is all about helping dental professionals and product developers think differently, make better decisions, and stay ahead of the curve. If you care about science, results, and doing things the right way, you're in the right place.

About your host

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Robert Karlinsey

Dr. Robert L. Karlinsey is a scientist and formulator with almost 20 years’ experience in dental research. He earned a BS in Physics (University of Scranton) and PhD in Chemical Physics (Indiana University), with postdoctoral work in physical chemistry (Indiana University). As a visiting assistant research professor at the Indiana University School of Dentistry, his research led to an impactful encounter with Dr. George Stookey, and shortly thereafter, the formation of Indiana Nanotech, LLC (now known as Custom Dental Formulations, LLC), of which he spearheaded all research and small-scale manufacturing efforts. Dr. Karlinsey is the inventor of Nanotech’s functionalized tricalcium phosphate systems, which continue to help generate over $100MM in global product sales for a major dental manufacturer. As Principal Investigator, his work has received significant funding through Federal (National Institutes of Health), State (Indiana and Texas), and industry grants and contracts. His research in patented calcium phosphate technologies continue to help generate over $100MM in global product sales. Previously, Dr. Karlinsey has served as Chief Scientific Officer at Therametric Technologies, Inc, and adjunct professor of chemistry at the University of Indianapolis.

Dr. Karlinsey addresses clients’ needs in preventive and cosmetic dentistry, including fluoride- and fluoride-free remineralization, antiplaque/gum health, whitening systems, and more. He is actively involved in clinical and laboratory research designs and performance-backed, customized oral care formulation solutions. And, whenever possible, he favors natural, nature-derived, and/or sustainably sourced ingredients