Dental Formulator's Playbook

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 [https://customdentalformulations.com/meet-dr-karlinsey?utm_source=chatgpt.com] Robert L. Karlinsey, PhD Google Scholar Profile [https://scholar.google.com/citations?hl=en&user=UI5EyjcAAAAJ] Subscribe to our newsletter: https://tamaras-newsletter-88aea5.beehiiv.com/ [https://tamaras-newsletter-88aea5.beehiiv.com/]

31: What Do Hops Have to Do with Toothpaste - The Brewing Science Behind a Surprising Oral Care Innovation with Dr. Rob Karlinsey and Tami

What if one of the most promising antimicrobial ingredients for toothpaste came from the same plant used to preserve beer? In this episode of Dental Formulator’s Playbook, Dr. Rob Karlinsey and co-host Tami explore an unexpected crossover between brewing science and oral care innovation. What do hops, Miller Brewing, and Procter and Gamble have to do with toothpaste? Quite a lot, it turns out. This conversation breaks down how hop compounds suppress lactobacilli in beer, why that same concept appeared in toothpaste patents decades ago, and how modern patent strategy may shape the next generation of oral care products. Highlights and Takeaways 1. Why hops are not just about bitterness, but also act as preservatives by suppressing lactobacilli and preventing beer spoilage 2. The surprising history of Miller Brewing filing an oral care patent in 1994, including toothpaste and mouthwash formulations that never reached market 3. How hop cones are harvested and kiln dried to reduce moisture and spoilage risk 4. What hops are made of, including cellulose, proteins, fats, resins, polyphenols, essential oils, and soluble fibers 5. Why the resins, not the essential oils or fibers, are the most relevant fraction for oral care 6. How hop resins are separated into soluble and insoluble fractions, and why the soluble fraction drives antimicrobial acid activity 7. The difference between hop alpha acids and hop beta acids, and why alpha acids matter most for bitterness and bacterial control 8. Why extremely low concentrations can still be biologically active, with hop alpha acids discussed at levels as low as 0.01 percent 9. How patent claims work in practice and why claim language matters more than the length of the patent 10. Why Procter and Gamble’s patent strategy expands beyond hop acids into additional resin derived compounds 11. The growing research interest in prenylated flavonoids and how their fat-affinity influences absorption and biological behavior 12. Why antimicrobial testing often fails to translate clinically once ingredients are placed into real toothpaste formulations 📲 Connect with Dr. Rob (Robert L. Karlinsey, PhD) 🌐 Website: customdentalformulations.com [https://customdentalformulations.com/meet-dr-karlinsey?utm_source=chatgpt.com] Robert L. Karlinsey, PhD Google Scholar Profile [https://scholar.google.com/citations?hl=en&user=UI5EyjcAAAAJ] Subscribe to our newsletter: https://tamaras-newsletter-88aea5.beehiiv.com/ [https://tamaras-newsletter-88aea5.beehiiv.com/]

30: Citric Acid Is Not What You Think - How Form Concentration and Context Change Everything with Dr. Rob Karlinsey and Tami

What if citric acid is not inherently good or bad, but misunderstood because formulation context is rarely explained? In this episode of Dental Formulator’s Playbook, Dr. Rob and co-host Tami take a deep, science-first look at one of the most widely used yet misunderstood ingredients in modern products: citric acid. Building on earlier episodes that examined citric acid’s role in foods and dental erosion, this conversation explores how citric acid is made, why it appears in everything from toothpaste to skincare to cleaners, and how its chemistry changes depending on form, concentration, and context. Dr. Rob explains the critical distinction between citric acid and citrate, why hydration state matters for formulators, and how citric acid functions as a buffer, chelator, preservative, and flavor modifier. The discussion traces citric acid’s industrial production back to early fermentation research, its historical link to penicillin scale-up through Pfizer, and its foundational role in cellular energy via the Krebs (citric acid) cycle. The episode also examines citric acid’s use in cosmetics as an alpha hydroxy acid, in household cleaners, in laboratory sample preservation, and in encapsulated food applications. Rather than framing citric acid as “good” or “bad,” this episode emphasizes understanding concentration, buffering, formulation design, and intended use to make informed decisions across oral care, food, skincare, and consumer products. Key Topics Covered 1. The difference between citric acid and citrate in aqueous systems 2. Why citric acid and sodium citrate behave the same once dissolved in water 3. Hydration states of raw materials (anhydrous, monohydrate, dihydrate) and why they matter for formulation accuracy 4. How citric acid functions as a buffer in pharmaceuticals and oral care products 5. Why citric acid is considered a natural ingredient despite industrial-scale production 6. Fermentation-based production of citric acid using Aspergillus niger 7. The historical link between citric acid scale-up and penicillin mass production 8. Pfizer’s role in advancing fermentation technology during World War II 9. James Currie’s 1917 research and its lasting impact on microbial production methods 10. Why fermentation is still the dominant method for producing citric acid today 11. Citric acid’s role in metabolism through the Krebs (citric acid) cycle 12. Alpha hydroxy acids (AHAs) and citric acid’s role in skincare formulations 13. Concentration differences between dental products, foods, cosmetics, and cleaners 14. Why buffering citric acid is critical in oral care and pharmaceutical products 15. Citric acid use in household cleaners, including modern low-toxicity formulations 16. Encapsulated citric acid in food applications and controlled-release systems 17. Why formulation context matters more than ingredient labels alone Highlights and Takeaways 1. Citric acid and citrate are chemically linked and convert based on pH once dissolved 2. Hydration state affects raw material weighing, not final function in solution 3. Fermentation, not fruit extraction, is how citric acid is produced at scale 4. Citric acid production enabled the industrial-scale manufacture of penicillin 5. The same citric acid found in foods, like lemons, is chemically identical to that produced by fermentation 6. Citric acid is central to cellular energy metabolism through the Krebs cycle 7. In oral care and pharmaceuticals, citric acid must be buffered for stability and safety 8. Concentration determines function, from gentle buffering to aggressive exfoliation 9. Lack of testing, not citric acid itself, creates risk in consumer products 10. Understanding chemistry allows better decisions across food, dental, skincare, and cleaning products References Fermentation of Citric Acid and Penicillin History 1. https://cen.acs.org/articles/83/i25/Penicillin.html [https://cen.acs.org/articles/83/i25/Penicillin.html?utm_source=chatgpt.com] 2. https://cen.acs.org/articles/86/i28/Pfizers-Penicillin-Landmark.html [https://cen.acs.org/articles/86/i28/Pfizers-Penicillin-Landmark.html?utm_source=chatgpt.com] 3. US Patent #540,267, Issued July 1, 1913; Inventor: Boleslas Zahorski 4. https://www.sciencedirect.com/science/article/pii/S0021925818867084 [https://www.sciencedirect.com/science/article/pii/S0021925818867084?utm_source=chatgpt.com] Krebs (Citric Acid) Cycle 1. https://link.springer.com/article/10.1186/s40694-018-0054-5 [https://link.springer.com/article/10.1186/s40694-018-0054-5] Alpha Hydroxy Acids (AHAs) 1. https://cen.acs.org/business/specialty-chemicals/7-acids-safely-put-face/104/web/2026/01 [https://cen.acs.org/business/specialty-chemicals/7-acids-safely-put-face/104/web/2026/01] Citric Acid Cleaning Formulations 1. US Patent #12,203,051 B2, Issued Jan 21, 2025; Assignee: Clorox Company Encapsulated Citric Acid in Food Applications 1. US Patent Application 2010/0330247 A1 (Abandoned); Assignee: Mondelez 📲 Connect with Dr. Rob (Robert L. Karlinsey, PhD) 🌐 Website: customdentalformulations.com [https://customdentalformulations.com/meet-dr-karlinsey?utm_source=chatgpt.com] Robert L. Karlinsey, PhD Google Scholar Profile [https://scholar.google.com/citations?hl=en&user=UI5EyjcAAAAJ] Subscribe to our newsletter: https://tamaras-newsletter-88aea5.beehiiv.com/ [https://tamaras-newsletter-88aea5.beehiiv.com/]

29: Healthy Drinks Can Still Harm Teeth - The Hidden Acid and Timing Factors Dentistry Misses with Dr. Rob Karlinsey and Tami

What if some of your most “healthy” choices for gut health are quietly eroding your teeth? In this episode of Dental Formulator’s Playbook, Dr. Rob and co-host Tami build on Episodes 26 and 27 to explain why pH alone does not tell the full story. They explore fermented dairy (yogurt, buttermilk, fermented milks), kombucha, and prebiotic cultures like lactobacilli, plus how timing, sipping habits, and formulation choices can increase risks for erosion and caries. The conversation also expands into restorative dentistry, including a 2024 study comparing two “compomer” materials (including the sparkly kid-friendly option) and how different liquids can change surface roughness over time. Key Topics Covered 1. Why the type of acid can predict damage better than pH alone 2. Fermented dairy basics: common pH range (about 4.0 to 4.5) and why buffering can be misleading 3. How lactobacilli tie into oral health: caries risk, acid production (lactic and sometimes acetic acid) 4. Why some “oral probiotic” mints can be a tradeoff, especially depending on your physiology 5. Kombucha pH (about 2.5 to 3.5) and why sipping over time can raise erosion risk 6. Timing matters: why yogurt or acidic drinks right before bed can be risky during low-saliva conditions 7. A children’s diet study reference: reported erosion rates tied to yogurt, orange juice, and carbonated drinks 8. A look at compomers (composite + glass ionomer hybrids): what they are and how they are used clinically 9. How exposure to cola, juice, water, and milk affected restoration surface roughness in a 2024 paper 10. Why roughness matters: plaque traps, periodontal risk, and even tooth appearance (light reflection) Highlights and Takeaways 1. “Healthy” does not always mean tooth-friendly. Gut benefits and enamel risks can coexist. 2. Sipping style and duration can matter as much as the drink itself. The longer acids linger, the higher the risk. 3. Fermented dairy can be well-buffered yet still contribute to enamel softening, especially with frequent exposure and poor timing. 4. Lactobacilli and its role as part of the caries picture, especially alongside streptococci, depending on the model and context. 5. Restorations have their own vulnerabilities. Some materials can roughen quickly in acidic liquids, while others may develop deposits over time. 6. A rough surface is not just cosmetic. It can create plaque traps and raise oral health risk. Practical Listener Tips 1. If you drink acidic beverages like kombucha, consider using a straw. 2. Avoid letting acidic drinks linger in the mouth by sipping slowly for long periods. 3. Be cautious with yogurt or fermented drinks right before bed, especially if you are not following with a solid oral hygiene routine. 4. Watch for “Swiss Army knife” claims that promise to fix everything. Your oral physiology may respond differently. 🔗 References & Supporting Research Fermented Foods and Health 1. Health benefits of fermented foods: 2. https://pmc.ncbi.nlm.nih.gov/articles/PMC9227559/ [https://pmc.ncbi.nlm.nih.gov/articles/PMC9227559/] Fermented Food & Beverage Consumption 1. Global fermented beverages market overview and consumption trends: 2. https://market.us/report/global-fermented-beverages-market/ [https://market.us/report/global-fermented-beverages-market/] 3. Traditional fermented foods and cultural consumption patterns: 4. https://www.gavi.org/vaccineswork/africas-traditional-fermented-foods-and-why-we-should-keep-consuming-them [https://www.gavi.org/vaccineswork/africas-traditional-fermented-foods-and-why-we-should-keep-consuming-them] Gastrointestinal Health Trends 1. Rising prevalence of gastrointestinal disorders in the U.S.: 2. https://gialliance.com/gastroenterology-blog/digestive-disease-continues-to-rise-among-americans/ [https://gialliance.com/gastroenterology-blog/digestive-disease-continues-to-rise-among-americans/] Dental Erosion and Population Studies 1. Dental erosion prevalence in Iranian 11-year-old children: 2. https://pubmed.ncbi.nlm.nih.gov/16119068/ [https://pubmed.ncbi.nlm.nih.gov/16119068/] Fermented Milk and Yogurt – Laboratory Studies 1. In vitro studies on fermented milk and enamel interaction: 2. http://dx.doi.org/10.13065/iksdh.2013.13.4.701 [http://dx.doi.org/10.13065/iksdh.2013.13.4.701] 3. Effects of fermented milk on deciduous enamel with and without fluoride: 4. https://www.researchgate.net/publication/256425298_The_effect_of_fermented_milk_on_the_deciduous_enamel_in_the_presence_and_absence_of_fluoride_in_vitro_study [https://www.researchgate.net/publication/256425298_The_effect_of_fermented_milk_on_the_deciduous_enamel_in_the_presence_and_absence_of_fluoride_in_vitro_study] 5. Additional laboratory studies on fermented dairy and enamel: 6. https://pubmed.ncbi.nlm.nih.gov/41331211/ [https://pubmed.ncbi.nlm.nih.gov/41331211/] 7. https://www.jksdh.or.kr/wp-content/uploads/2025/02/JKSDH-2105-03.pdf [https://www.jksdh.or.kr/wp-content/uploads/2025/02/JKSDH-2105-03.pdf] 8. https://koreascience.kr/article/JAKO202408632404126.pdf [https://koreascience.kr/article/JAKO202408632404126.pdf] Fermented Milk – In Situ Clinical Research 1. In situ clinical study on fermented milk and enamel: 2. https://pubmed.ncbi.nlm.nih.gov/19945694/ [https://pubmed.ncbi.nlm.nih.gov/19945694/] Compomers and Beverage Exposure 1. Overview of dental composite resins and compomers: 2. https://www.sciencedirect.com/topics/medicine-and-dentistry/dental-composite-resin [https://www.sciencedirect.com/topics/medicine-and-dentistry/dental-composite-resin] 3. Effects of frequently consumed beverages on compomer surface roughness: 4. https://www.researchgate.net/publication/378846907_Effects_of_frequently_consumed_beverages_by_children_on_the_surface_roughness_of_compomers [https://www.researchgate.net/publication/378846907_Effects_of_frequently_consumed_beverages_by_children_on_the_surface_roughness_of_compomers] 📲 Connect with Dr. Rob (Robert L. Karlinsey, PhD) 🌐 Website: customdentalformulations.com [https://customdentalformulations.com/meet-dr-karlinsey?utm_source=chatgpt.com] Robert L. Karlinsey, PhD Google Scholar Profile [https://scholar.google.com/citations?hl=en&user=UI5EyjcAAAAJ] Subscribe to our newsletter: https://tamaras-newsletter-88aea5.beehiiv.com/ [https://tamaras-newsletter-88aea5.beehiiv.com/]

28: Published Does Not Mean Proven - The Shocking Truth About Scientific Corrections with Dr. Rob Karlinsey

What if some of the research shaping everyday products is quietly flawed, and the system designed to correct it often chooses not to? In this episode of Dental Formulator’s Playbook, Dr. Rob and co-host Tami take a deep, unfiltered look at scientific ethics and research accountability. Prompted by recent survey data and real-world case studies, the conversation explores how flawed or falsified research can enter the scientific record and why it so often remains there uncorrected. Rather than focusing on isolated mistakes, this episode examines systemic behaviors. These include informal admissions, delayed accountability, and the reluctance to issue corrections or retractions even when problems are known. From high-profile superconductivity claims to modern AI-driven research, Dr. Rob explains why transparency, replication, and proper testing models are essential, especially when scientific papers are used to justify claims in oral care products and other consumer-facing technologies. This discussion challenges listeners to think more critically about what “published” really means and how to evaluate research beyond headlines and abstracts. Key Topics Covered 1. Findings from a published survey examining how often chemists knowingly falsify information in scientific papers 2. What falsification can look like beyond simple errors, including selective data presentation and procedural shortcuts 3. Why many researchers avoid formal corrections and how those decisions are commonly rationalized 4. Informal and non-public ways errors are addressed instead of correcting the scientific record 5. How scrutiny can occur outside traditional journals through independent review and public forums 6. A detailed case study involving high-profile superconductivity claims and failed replication attempts 7. Why highly publicized fields like AI attract attention, while similar ethics risks exist across all areas of science 8. How Dr. Rob evaluates whether research is trustworthy, relevant, and clinically meaningful 9. The role of appropriate models, controls, and independent replication in supporting oral care product claims Highlights and Takeaways 1. Published does not mean proven. Peer-reviewed publication alone is not a guarantee of accuracy or reliability. 2. The scientific record often remains uncorrected. Many known issues are never formally addressed through corrections or retractions. 3. Replication is essential. When independent groups cannot reproduce results, confidence in those findings should decrease. 4. Models and controls matter. Meaningful positive and negative controls are critical for interpreting results responsibly. 5. Bias influences what gets promoted. Financial incentives, career pressure, and marketing interests can shape scientific narratives. Reference Links Karlinsey & Karlinsey – Recently Published Research Methods and Protocols paper examining formulation science and measurement models: https://doi.org/10.3390/mps9010010 [https://doi.org/10.3390/mps9010010] Scientific Accountability and Publication Ethics Survey findings discussed by Accountability in Research and ACS Chemical & Engineering News on deliberate inclusion of misleading information in published papers: https://doi.org/10.1080/08989621.2025.2564106 [https://doi.org/10.1080/08989621.2025.2564106] https://cen.acs.org/policy/publishing/One-five-chemists-deliberately-added/103/web/2025/10 [https://cen.acs.org/policy/publishing/One-five-chemists-deliberately-added/103/web/2025/10] Retracted Superconductivity Papers (Science and Nature) Commentary and official retraction notices for eight papers in Science and one paper in Nature: https://www.science.org/doi/10.1126/science.298.5595.961b [https://www.science.org/doi/10.1126/science.298.5595.961b] https://www.nature.com/articles/nature01467 [https://www.nature.com/articles/nature01467] University of Rochester Superconductivity Retractions (Nature 2020 & 2023) Editorial notices addressing retracted claims of room-temperature superconductivity: https://www.nature.com/articles/s41586-022-05294-9 [https://www.nature.com/articles/s41586-022-05294-9] https://www.nature.com/articles/s41586-023-05742-0.epdf [https://www.nature.com/articles/s41586-023-05742-0.epdf] Fraudulent AI Research Activity at MIT Wall Street Journal reporting and official MIT statement addressing inaccurate research records and ethics concerns: https://www.wsj.com/economy/aidan-toner-rodgers-mit-ai-research-78753243 [https://www.wsj.com/economy/aidan-toner-rodgers-mit-ai-research-78753243] https://economics.mit.edu/news/assuring-accurate-research-record [https://economics.mit.edu/news/assuring-accurate-research-record] 📲 Connect with Dr. Rob (Robert L. Karlinsey, PhD) 🌐 Website: customdentalformulations.com [https://customdentalformulations.com/meet-dr-karlinsey?utm_source=chatgpt.com] Robert L. Karlinsey, PhD Google Scholar Profile [https://scholar.google.com/citations?hl=en&user=UI5EyjcAAAAJ] Subscribe to our newsletter: https://tamaras-newsletter-88aea5.beehiiv.com/ [https://tamaras-newsletter-88aea5.beehiiv.com/]