Modern toothpastes are complex formulations with various ingredients. The aim of this study was to analyze the improvement of toothpaste formulations from 1900 to 2023 focusing on active ingredients with remineralizing, antibacterial, or plaque-removing effects, and to discuss their influence on caries prevention. For this, worldwide patent applications were searched using the international database Espacenet from the European Patent Office. Additionally, toothpaste products were searched using the Mintel product database from 1996 to 2023. The searched ingredients were (in alphabetical order): calcium carbonate, calcium phosphates, hydrated silica, sodium fluoride, sodium lauryl sulfate, triclosan, xylitol, and zinc salts as they are known from the scientific literature to be remineralizing or antibacterial/antiplaque agents. It was shown that the number of patent applications containing these ingredients significantly increased since the 1970s. As these ingredients have remineralizing, antibacterial, or plaque-removing effects, they all can contribute to caries prevention. In conclusion, and within the limitations of this approach, this study shows that toothpaste formulations have greatly improved over the past decades by using various active anticaries ingredients.

Spatial navigation research in humans increasingly relies on experiments using virtual reality (VR) tools, which allow for the creation of highly flexible, and immersive study environments, that can react to participant interaction in real time. Despite the popularity of VR, tools simplifying the creation and data management of such experiments are rare and often restricted to a specific scope—limiting usability and comparability. To overcome those limitations, we introduce the Virtual Navigation Toolbox (VNT), a collection of interchangeable and independent tools for the development of spatial navigation VR experiments using the popular Unity game engine. The VNT’s features are packaged in loosely coupled and reusable modules, facilitating convenient implementation of diverse experimental designs. Here, we depict how the VNT fulfils feature requirements of different VR environments and experiments, guiding through the implementation and execution of a showcase study using the toolbox. The presented showcase study reveals that homing performance in a classic triangle completion task is invariant to translation velocity of the participant’s avatar, but highly sensitive to the number of landmarks. The VNT is freely available under a creative commons license, and we invite researchers to contribute, extending and improving tools using the provided repository.

Introduction: In order to successfully move from place to place, our brain often combines sensory inputs from various sources by dynamically weighting spatial cues according to their reliability and relevance for a given task. Two of the most important cues in navigation are the spatial arrangement of landmarks in the environment, and the continuous path integration of travelled distances and changes in direction. Several studies have shown that Bayesian integration of cues provides a good explanation for navigation in environments dominated by small numbers of easily identifiable landmarks. However, it remains largely unclear how cues are combined in more complex environments. Methods: To investigate how humans process and combine landmarks and path integration in complex environments, we conducted a series of triangle completion experiments in virtual reality, in which we varied the number of landmarks from an open steppe to a dense forest, thus going beyond the spatially simple environments that have been studied in the past. We analysed spatial behaviour at both the population and individual level with linear regression models and developed a computational model, based on maximum likelihood estimation (MLE), to infer the underlying combination of cues. Results: Overall homing performance was optimal in an environment containing three landmarks arranged around the goal location. With more than three landmarks, individual differences between participants in the use of cues are striking. For some, the addition of landmarks does not worsen their performance, whereas for others it seems to impair their use of landmark information. Discussion: It appears that navigation success in complex environments depends on the ability to identify the correct clearing around the goal location, suggesting that some participants may not be able to see the forest for the trees.

Background: Tooth enamel is the hardest and most highly mineralized tissue in the human body. It serves as a protective barrier against chemical, mechanical, and microbial challenges. Despite its durability, enamel remains vulnerable to developmental and posteruptive defects such as fluorosis, hypomineralization, and amelogenesis imperfecta (AI). For oral health professionals, a clear understanding of the biological and molecular mechanisms underlying enamel formation is essential for advancing preventive and therapeutic strategies in clinical practice. This review synthesizes current knowledge on enamel formation, with emphasis on its cellular, molecular, and structural determinants, and discusses clinically relevant disruptions as well as emerging biomimetic approaches. Methods: This scoping review was conducted according to the PRISMA-ScR guidelines. A systematic literature search of the mechanisms of enamel formation was performed via Embase and Medline. Titles and abstracts were screened independently by three authors. Studies that primarily addressed enamel defects were excluded from the systematic synthesis; however, these studies were retained for narrative discussion. Following the screening process, 92 publications met the inclusion criteria and were incorporated into the thematic synthesis. Results: Enamel formation is a complex, multistage process involving epithelial–mesenchymal interactions and the sequential activity of ameloblasts during presecretory, secretory, transition, and maturation stages. Key mechanisms include the secretion of enamel matrix proteins (e.g., amelogenin, ameloblastin, and enamelin), proteolytic processing by enzymes such as MMP20 and KLK4, and controlled ion transport, leading to hydroxyapatite crystal growth and organization into rod and interrod structures. The structural arrangement endows enamel with exceptional mechanical resistance. Narrative sections address “What can go wrong?”, summarizing genetic, epigenetic, and environmental causes of fluorosis, hypomineralization, and amelogenesis imperfecta, and other developmental defects, whereas “What can we learn from nature?” highlights biomimetic strategies. Conclusions: Human enamel formation is a highly coordinated biomineralization process regulated at the cellular, structural, and molecular levels. Disruptions in these processes underlie major enamel pathologies. Integrating mechanistic insights from natural enamel development with emerging biomimetic technologies offers promising avenues for prevention, diagnosis, and treatment in dentistry. This review provides oral health professionals with a biologically grounded framework to guide evidence-based management of enamel-related conditions.

To systematically identify and evaluate clinical trials assessing the caries-preventive efficacy of fluoride-free active ingredients in toothpaste formulations. Randomized clinical trials analyzing the caries preventive effect of fluoride-free active ingredients in toothpastes. A PRISMA-related systematic review of MEDLINE and Embase was conducted. Inclusion criteria were human in vivo clinical trials on toothpastes, fluoride-free interventions, and caries-focused outcomes; exclusion criteria were in vitro or animal studies, non-toothpaste products, fluoride-only products, and non-English publications. The review followed the PICO framework: Population - participants of all ages with primary, mixed, or permanent dentition; Intervention - use of a toothpaste with a non-fluoride active ingredient; Comparison - a fluoride-containing toothpaste as control; Outcome - a measurable oral health effect based on in vivo caries estimation. Fifteen clinical trials met the inclusion criteria. Eleven used fluoride-free, non-therapeutic abrasive toothpastes as placebo controls. Three trials evaluated the caries-preventing efficacy of fluoride-free hydroxyapatite toothpastes across children, adolescents, and adults; one trial evaluated the caries-preventive efficacy of fluoride-free arginine toothpaste in children. Caries prevention relies on reducing sugar intake and thorough daily oral care, with toothpaste, containing evolving combinations of remineralizing agents, antibacterials, and abrasives, playing a central role. With growing global interest in fluoride-free options, this literature review shows that clinically proven fluoride alternatives are already in use. This review provides evidence-based guidance for dentists when recommending fluoride-free toothpastes to patients.

Dental caries is highly prevalent worldwide and represents a major oral-health challenge. Although commonly labelled as a disease, this terminology may not fully capture its biological, chemical, and clinical nature. The aim of this review is to examine whether dental caries is best conceptualized as a discrete disease entity or as a dynamic, site-specific pathological process characterized by biofilm dysbiosis and disturbed mineral homeostasis at the tooth surface. Unlike many classical disease entities, caries does not represent a clearly defined binary state, but develops gradually from subclinical mineral imbalance to non-cavitated lesions, cavitation, and pulpal complications. It results from a dynamic imbalance between demineralization and remineralization at the tooth surface rather than from a single causative pathogen. Moreover, clinical relevance and treatment need depend on lesion activity, lesion severity, and individual risk context, not merely on the presence of a lesion. Early caries lesions are biologically active and can be arrested or reversed by restoring ecological and physicochemical balance at the tooth surface. Caries progression is strongly influenced by diet, oral hygiene, saliva, oral microbiome dysbiosis, and biofilm ecology, and can often be controlled through preventive and non-invasive measures. Therefore, dental caries is best understood not as a classical disease entity, but as a pathological process affecting the dental hard tissues—one that is fundamentally preventable, controllable, and, in its early stages, reversible.