Optimization of a Novel Toothpaste Formulation, Balancing Cleaning Efficacy, Enamel Polishing, and Minimal Abrasivity (Preprint)

BACKGROUND The incorporation of abrasives in oral care formulations has a long history, dating back to ancient civilizations. Early oral hygiene practices relied on crude materials such as crushed bones, oyster shells, and burnt eggshells to remove debris and stains from the teeth. While these substances provided mechanical cleaning, their abrasiveness often resulted in significant enamel wear. With advancements in dental science and material development, the 19th and 20th centuries saw the introduction of milder abrasives in toothpaste formulations. Calcium carbonate and sodium bicarbonate became common ingredients, offering improved cleaning efficacy while reducing enamel damage. By the mid-20th century, the development of synthetic abrasives, such as hydrated silica, revolutionized toothpaste formulations, providing controlled abrasivity and enhanced stain removal without compromising enamel integrity. Modern Abrasive Agents in Toothpaste; contemporary dentifrices formulations utilize a range of abrasives, each selected based on their effectiveness in plaque and stain removal, as well as their impact on enamel and dentin surfaces. Key abrasives currently used in oral care include Hydrated Silica; Kaolin Clay; Activated Charcoal; Calcium Carbonate; Perlite Dental Patients often rely on product labels and marketing claims when selecting oral care products, yet the true efficacy of these formulations is not always immediately perceptible. The effectiveness of a toothpaste or mouthwash extends beyond its advertised benefits, as many factors—such as active ingredient bioavailability, formulation stability, and long-term clinical performance—remain imperceptible to the average user. Scientific research underscores the importance of evidence-based oral hygiene practices, guided by dental professionals rather than commercial narratives. Many product claims lack rigorous clinical validation, with some relying on superficial whitening effects or temporary freshness rather than substantiated oral health benefits. Regulatory frameworks allow for marketing terminology that may not always align with real-world effectiveness, making professional guidance essential in identifying truly beneficial products. Furthermore; in modern oral care, the Relative Dentin Abrasivity (RDA) value is often misinterpreted as the sole determinant of toothpaste safety and effectiveness. While RDA measures the abrasive impact on dentin, it does not provide a complete picture of a dentifrice’s overall cleaning performance or oral health benefits. This narrow focus has led to misconceptions, where consumers and even some professionals equate lower RDA values with safer and more effective formulations—an oversimplification that overlooks key scientific factors. Toothpaste efficacy extends beyond abrasivity, requiring a more comprehensive evaluation that includes metrics such as Pellicle Cleaning Ratio (PCR) and Enamel Polishing Potential (EPP). PCR assesses the ability of a formulation to remove stains and biofilm, while EPP evaluates its impact on enamel polishing. A well-balanced formulation must optimize all these parameters, ensuring effective plaque and stain removal without causing excessive wear or compromising enamel protection. The current overemphasis on RDA highlights the need for greater education in the field of oral care science. Dental professionals require to guide patients toward evidence- based decision-making, considering the full spectrum of formulation attributes rather than relying solely on isolated values. By fostering a deeper understanding of how multiple scientific factors contribute to toothpaste performance, we can move toward a more informed and effective approach to daily oral hygiene. OBJECTIVE This study aims to: • Evaluate, using conventional in vitro procedures, the abrasivity, enamel polishing properties, and stain removal effectiveness of kaolin, perlite-based dentifrices, and compare them with commercially available products that have varying compositions, marketed for cleaning, whitening, and/or polishing. The relationship between stain removal and abrasivity will also be examined. • Develop a novel kaolin-perlite-based toothpaste that provides high cleaning efficacy while preserving enamel integrity. • Compare the abrasive effects of kaolin-perlite formulations with those of commercial silica-based and other abrasive dentifrices. • Assess the remineralization potential of the toothpaste formulation using hydroxyapatite and calcium carbonate. METHODS 3.1 PCR Testing a) ISO/ADA Reference Material b) Toothpaste Sample: Whitening & Total CareTM 3.2 RDA Description of the abrasivity test method 3.3 Enamel Polishing Potential RESULTS 4.1. Quantitative Analysis of Cleaning and Abrasivity The kaolin-perlite formulation demonstrated high stain removal, superior enamel polishing, and low abrasivity, CONCLUSIONS The effectiveness of dentifrices in removing stains, their abrasiveness, and their ability to polish enamel showed considerable variation, particularly among those containing silica-based abrasives. There was no clear or consistent correlation between these properties and the abrasives listed on the product labels. Over 60 years ago, Kitchin and Robinson highlighted the importance of using just enough abrasiveness to clean teeth effectively, a sentiment that remains relevant today. The challenge, however, lies in determining what constitutes the "right" amount of abrasiveness. (Bruce R. Schemehorn, 2011). Generally, whitening or cleaning toothpastes were found to be more abrasive than their non-whitening counterparts, though there were exceptions to this trend. Additionally, a direct relationship between the ability to remove stains and the level of abrasivity was not always evident. Similarly, toothpastes marketed for their polishing or luster-enhancing qualities were not necessarily more effective than other products. However, the most effective product in the study used refined kaolin clay as its abrasive. The toothpaste formulated with kaolin, perlite, hydroxyapatite, and tetrasodium pyrophosphate delivers expected performance in key areas of oral care. It demonstrates superior stain removal and enamel polishing, with a Pellicle Cleaning Ratio (PCR) of 145.6, significantly higher than the ISO/ADA reference standard. The Cleaning Efficiency Index (CEI) of 2.01 highlights excellent cleaning power while maintaining a low dentin abrasivity (RDA) of 95, ensuring minimal wear on tooth surfaces. The Enamel Polishing Potential (EPP) score of 87.7 reflects a smooth, polished surface that reduces stain accumulation over time. Additionally, hydroxyapatite and calcium carbonate contribute to enamel remineralization, strengthening the tooth structure and reducing sensitivity. A formula sets a new standard in the oral care market, offering a powerful, gentle, and remineralizing solution for effective stain removal, enamel protection, and polishing.