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

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...

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...

What if the real risk to your enamel isn’t just how acidic a drink is, but the specific acids hidden inside it that change how your teeth dissolve?

In this episode of Dental Formulator’s Playbook, Dr. Rob and Tami break down how acidic drinks impact enamel demineralization, and why the “type of acid” matters, not just pH. They start with a surprising discussion on Pedialyte, explaining how a low pH plus citric acid and citrate salts can raise erosion risk, especially when calcium is absent. Then they compare major sodas and flavored waters, highlighting how acids like phosphoric acid, citric acid, and benzoic acid show up across brands for both preservation and taste. The episode closes with practical ways to reduce damage, plus a few “safer” sparkling water picks based on pH.

Highlights

1. Why pH below 5.5 increases demineralization risk (and how fluoride changes resistance)
2. The surprising enamel risk with Pedialyte (especially without calcium)
3. Coke vs. Pepsi: acid profiles and why “cola acid” is not always the same
4. Why benzoic acid shows up in drinks for more than preservation
5. A practical enamel-saving approach for acidic drinks when you are sick, dehydrated, or dry-mouthed
6. Flavored waters: why “it’s just water” can still be a problem
7. Which sparkling waters land closer to “gentler” pH territory

Practical Takeaways

1. Avoid brushing immediately after acidic drinks. Wait at least 30 minutes.
2. If you must use acidic electrolyte drinks, consider damage control strategies discussed in the episode (timing, fluoride support, and calcium buffers).
3. Flavored waters often contain citric acid and may sit below enamel-safe pH ranges.
4. Plain sparkling waters can vary. Some test closer to the safer side, but citrus flavors tend to drop pH.

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

🌐 Website: customdentalformulations.com

Robert L. Karlinsey, PhD

Google Scholar Profile

What if the real danger to your teeth isn’t that fruit is acidic, but that different fruit acids strip enamel in very different ways most people never learn about?

In this episode of Dental Formulator’s Playbook, Dr. Rob and Tami break down the chemistry behind fruit acids and their real impact on dental erosion. While fruits are often grouped together as “acidic,” the hosts explain why citric acid, malic acid, and tartaric acid behave very differently once they interact with enamel, saliva, and calcium.

Using clear chemistry explanations and published research, the conversation explores why oranges pose a higher erosion risk than apples, how calcium binding changes as pH shifts in the mouth, and why certain acids are routinely used in dental erosion testing models. The episode also covers practical, evidence-based strategies to reduce acid damage without avoiding healthy foods altogether.

🔍 Episode Highlights

1. Why acidic foods are not equally damaging to teeth
2. The difference between dental erosion and dental caries
3. Citric acid vs malic acid vs tartaric acid explained simply
4. How calcium binding strength determines erosion risk
5. Why citric acid is the standard acid used in erosion research models
6. How pH shifts in the mouth amplify mineral loss
7. The role of EDTA and why its chelation strength matters
8. Why calcium-fortified beverages reduce enamel damage
9. How wine and sports drinks contribute to dental erosion
10. The science behind brushing timing after acidic exposure

🧪 Key Takeaways

1. Different fruits expose teeth to different acids, which vary in erosive potential
2. Apples primarily contain malic acid, which has lower calcium-binding strength
3. Oranges primarily contain citric acid, which is more erosive due to stronger calcium binding
4. Grapes primarily contain tartaric acid, which behaves more similarly to citric acid than malic acid
5. Citric acid contains three carboxylic acid groups, allowing it to bind calcium more aggressively at oral pH
6. Stronger calcium binding increases enamel mineral loss compared to acids with fewer binding sites
7. EDTA binds calcium far more strongly than fruit acids and must be carefully managed in dental formulations
8. Citrus fruits and juices pose a higher erosion risk than apples
9. Calcium-rich foods and beverages can act as sacrificial calcium to reduce enamel damage
10. Calcium-fortified...

What happens when a best-selling pet oral care product is examined ingredient by ingredient instead of through marketing claims?

In this episode of Dental Formulator’s Playbook, Dr. Rob and Tami take a close, evidence-based look at Vet’s Best Enzymatic Dog Toothpaste, a product with tens of thousands of reviews and strong consumer trust. The discussion focuses on formulation transparency, ingredient safety, and whether the product’s claims align with canine oral biology and real formulation science.

Dr. Rob breaks down each ingredient, including enzymes, glycerin, aloe, and neem oil, and explains why popularity and sales volume are not substitutes for safety data or biological relevance. Special attention is given to the quiet removal of neem oil from marketing language while it remains in the ingredient list, raising concerns about transparency rather than reformulation.

This episode encourages pet owners to read labels carefully, question buzzwords like “enzymatic” and “natural,” and prioritize evidence-based formulations over trends.

🔍 Highlights

1. Why dogs and cats do not develop dental caries like humans
2. The difference between human and veterinary oral care needs
3. What glucose oxidase enzymes actually do and why they may not benefit pets
4. Concerns around neem oil remaining in the formula despite removal from marketing claims
5. Potential gastrointestinal risks associated with neem oil and aloe
6. How glycerin-heavy, water-free formulations affect brushing performance
7. Why “safe to swallow” claims deserve extra scrutiny
8. The risks of equating high sales and positive reviews with product safety
9. How misleading marketing language can obscure formulation reality
10. The importance of ingredient transparency in veterinary oral care

💡 Key Takeaways

1. Dogs do not get cavities, so caries-focused enzymes offer limited benefit
2. Ingredient transparency matters more than marketing language
3. Neem oil is a potent antimicrobial not intended for ingestion
4. Removing claims without removing ingredients reduces consumer trust
5. “Natural” does not automatically mean safe for pets
6. Sales volume and reviews are not safety indicators
7. Evidence-based formulation should guide pet oral care decisions

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

🌐 Website: customdentalformulations.com

📄 Research Profile:

What if vitamin D supports your oral health in powerful ways, but not in the cavity preventing role social media claims it does?

In this episode of Dental Formulator’s Playbook, Dr. Rob and Tami take a deep, evidence-based look at vitamin D and its relationship to oral health. They examine historical research, modern studies, and emerging science to clarify what vitamin D can and cannot do for teeth and gums. While vitamin D is often promoted online as a cavity-preventing solution, the hosts explain why fluoride remains the gold standard for caries prevention and where vitamin D actually fits into a smart, holistic oral care strategy.

Rather than acting directly on enamel, vitamin D influences oral health through systemic pathways, including immune regulation, salivary protein expression, and periodontal tissue support. This episode separates fact from hype and offers practical guidance grounded in real science.

🔍 Highlights

1. Why vitamin D does not directly prevent dental caries
2. The difference between systemic support and topical protection
3. How vitamin D influences the oral proteome and salivary proteins
4. The role of antimicrobial peptides such as cathelicidin (LL-37) in oral immunity
5. Historical vitamin D research and how early findings were often misinterpreted
6. Why fluoride remains essential for enamel protection and remineralization
7. Vitamin D’s documented benefits for gingival health and periodontal stability
8. The importance of distinguishing correlation from causation in nutrition research
9. How saliva flow and protein composition affect oral defense mechanisms
10. Where vitamin D fits into a comprehensive, evidence-based oral care approach

💡 Key Takeaways

1. Supplementing with Vitamin D benefits the oral environment in terms of gingival and periodontal health, however there is no clear association in preventing dental caries (i.e., not by strengthening enamel or preventing cavities)
2. Fluoride is still the most effective and only approved anti-caries agent
3. Adequate vitamin D levels improve gum health, immune response, and salivary protein function
4. Salivary proteins play a critical role in protecting teeth and soft tissues
5. Nutrition matters, but it cannot replace proper topical oral care
6. A holistic approach combines fluoride, good hygiene, diet, and systemic health

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

🌐 Website:...

What if the most important protection for your teeth isn’t in your toothpaste at all, but in the salivary proteins you may be unknowingly stripping away every day?

In this episode, Dr. Rob and Tami explore a critical but often overlooked aspect of oral health: the salivary proteins that naturally protect teeth. The conversation focuses on the acquired enamel pellicle, a protein rich layer that forms on enamel within seconds and plays a key role in defense, remineralization, and microbial balance.

They discuss how aggressive cleaning products, chronic whitening treatments, and poor brushing timing, especially after acidic drinks, can unintentionally damage this protective layer. The episode compares fluoride based approaches with peptide based technologies, explains why some treatments underperform clinically, and highlights how respecting the mouth’s natural biology leads to better long term outcomes.

Key Topics Covered

1. What the acquired enamel pellicle is and why it matters
2. The role of salivary proteins in enamel protection and remineralization
3. How aggressive whitening and cleaning agents can disrupt oral defenses
4. Why brushing immediately after acidic drinks accelerates enamel wear
5. Differences between fluoride based and peptide based treatments
6. Why some peptide technologies fail in real world clinical studies
7. How salivary proteins influence tartar formation and erosion risk
8. The importance of timing, pH, and product choice in daily oral care
9. Why stannous fluoride works synergistically with salivary proteins
10. Practical strategies to protect enamel without over stripping it

Practical Takeaways

1. Avoid brushing teeth immediately after acidic drinks like orange juice, soda, or energy drinks
2. Allow saliva time to rebuild the pellicle layer before mechanical brushing
3. Be cautious with chronic use of highly alkaline, fluoride free, or protein stripping products
4. Understand that “cleaner” does not always mean healthier for enamel
5. Choose products that work with salivary proteins rather than against them
6. Recognize that enamel erosion is permanent and prevention is critical

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

🌐 Website: customdentalformulations.com

📄 Research Profile: Robert Karlinsey on ResearchGate