The use of hydroxyapatite toothpaste to prevent dental caries.

Dissolution of hydroxyapatite from the tooth structure at low pH can lead to the irreversible destruction of enamel and dentin, which if left untreated can result in pain and tooth loss. Hydroxyapatite toothpastes contain hydroxyapatite particles in micro- or nanocrystalline form that have been shown to deposit and restore demineralized enamel surfaces. As such, they are currently being explored as a fluoride-free anti-caries agent. This narrative review article aims to summarize the recent findings of the research investigating the remineralization potential of HAP toothpaste in vitro, in situ and in vivo, as well as some other applications in dentistry.

Ca2+ release and buffering effects of synthetic hydroxyapatite following bacterial acid challenge.

BACKGROUND: Synthetic particulate hydroxyapatite (HAP; Ca5(PO4)3(OH)) is used as ingredient in oral care products but its effects on cariogenic biofilms are not clear yet. The primary mode of action of HAP may be acting as a calcium phosphate reservoir when deposited in oral biofilms and release Ca2+ and (hydrogen) phosphate ions upon bacterial acid challenge. The aim of this in vitro study was to test this hypothesis by investigating release of Ca2+ ions and potential buffering effects from HAP upon bacterial acid challenge in planktonic cultures and biofilms of Streptococcus mutans. METHODS: Planktonic cultures of S. mutans were grown in BHI broth with 1% sucrose or with additional 5% HAP or 5% silica for up to 48 h. Separately, biofilms of S. mutans were grown in BHI for 72 h in total. After 24 h of this biofilm culture, either BHI alone or BHI with additional 0.5% HAP or 0.5% silica was added. After 48 h, BHI with 1% sucrose was added to allow bacterial acid formation. Ca2+ release was determined colorimetrically and pH measurements were performed using a pH electrode. For statistical analysis, non-parametrical procedures were applied (n ≥ 10; Mann-Whitney U test; α = 0.05). RESULTS: Relevant release of Ca2+ was only evident in planktonic cultures or biofilms with HAP but not in both other groups (p ≤ 0.001). In suspended biofilms with HAP, median pH was 4.77 after 72 h and about 0.5 pH units higher as compared to both other groups (4.28 or 4.32, respectively; p ≤ 0.001). CONCLUSIONS: Under the tested conditions, synthetic HAP releases Ca2+ ions upon bacterial acid challenge and may also show some buffering capacity but further studies are needed to investigate whether the concentrations tested here can also be reached clinically in dental biofilms.

Synthetic Hydroxyapatite as a Biomimetic Oral Care Agent.

PURPOSE: Human tooth enamel consists mostly of minerals, primarily hydroxyapatite, Ca10(PO4)6(OH)2, and thus synthetic hydroxyapatite can be used as a biomimetic oral care agent. This review describes the synthesis and characterization of hydroxyapatite from a chemist's perspective and provides an overview of its current use in oral care, with a focus on dentin hypersensitivity, caries, biofilm management, erosion, and enamel lesions. SOURCES: Reviews and original research papers published in English and German were included. RESULTS: The efficiency of synthetic hydroxyapatite in occluding open dentin tubules, resulting in a protection for sensitive teeth, has been well documented in a number of clinical studies. The first corresponding studies on caries, biofilm management and erosion have provided evidence for a positive effect of hydroxyapatite either as a main or synergistic agent in oral care products. However, more in situ and in vivo studies are needed due to the complexity of the oral milieu and to further clarify existing results. CONCLUSIONS: Due to its biocompatibility and similarity to biologically formed hydroxyapatite in natural tooth enamel, synthetic hydroxyapatite is a promising biomimetic oral care ingredient that may extend the scope of preventive dentistry.

Case Report on Caries Assessment Using Intraoral Scanner Compared with Bitewing Radiographs.

Dental caries remains one of the main reasons patients seeing their dentist. They either show up for preventive measures, diagnostics, or treatment of present caries lesions. To date, diagnostics are performed visually, supported by using bitewing radiographs. While radiographic diagnostics should only be performed on a biannual basis, and some caries process will not be seen with visual diagnostics, there remains a lack in regular checkups. Therefore, different technical applications can be used for regular diagnostics. One of those is the near-infrared imaging (NIRI) technology. In this case report, a patient presented with incipient caries lesions. These lesions were diagnosed visually, radiographically, and using NIRI. After diagnosis of incipient caries lesions, the patient was advised to use a hydroxyapatite toothpaste and a hydroxyapatite gel for the remineralization of the lesions and prevention of caries progression. The patient was followed up for 6 months with regular checkups in between. Visual diagnostics and NIRI were used to detecting the caries progress. After 6 months, bitewing radiographs were used in addition. In this clinical investigation we were able to show for the first time that NIRI and bitewing radiographs are able to detect and follow incipient caries lesions. Additionally, this study highlights that hydroxyapatite-containing oral care products are able to arrest and remineralize the caries process.

Prevention of Dental Caries: A Review on the Improvements of Toothpaste Formulations from 1900 to 2023.

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.

Doses of fluoride toothpaste for children up to 24 months.

AIM: The aim of this study was to test the dose of fluoride toothpaste by parents for their children aged up to 24 months. METHODS: Parents who use fluoride toothpastes for their children were asked to dose two commercially available toothpastes (A and B) with 1000 ppm fluoride each for their children as they would normally do at home. The toothpaste amounts were weighed, and as reference, the weight of an 'optimal' grain of rice-size amount of each toothpaste was used. RESULTS: 61 parents dosed a mean of 0.263 ± 0.172 g toothpaste A and 0.281 ± 0.145 g toothpaste B. The parents' mean doses were 5.9 times higher for toothpaste A and 7.2 times higher for toothpaste B than an 'optimal' grain of rice-size amount (the reference dose as recommended). The difference between parent's and reference dose was statistically significant (p < 0.001). Moreover, 39.3% of parents were not aware about conditions of use and warnings that have to be printed on the package of fluoride toothpastes. CONCLUSION: In this study, parents significantly overdosed the toothpaste for their children. To avoid fluoride intake from toothpaste, parents can choose fluoride-free alternatives for the oral care of their infants and toddlers.

Caries Etiology and Preventive Measures.

Caries is a widespread disease in both children and adults. Caries is caused by the conversion of fermentable carbohydrates by plaque bacteria into acids on the tooth surface. Thus, it is important to focus on sugar reduction and plaque control. For efficient plaque removal/control, state-of-the-art toothpastes contain various active ingredients such as antimicrobial agents (e.g., chlorhexidine, stannous salts, and zinc salts), abrasives (e.g., calcium carbonate, calcium phosphates, and hydrated silica), surfactants (e.g., sodium lauryl sulfate and sodium methyl cocoyl taurate), and natural compounds (e.g., polyphenols and xylitol). Agents with pH-buffering and calcium-releasing properties (e.g., calcium carbonate and calcium phosphates) and biomimetic actives (e.g., hydroxyapatite) reverse the effects of the acids. Additionally, modern toothbrushes (i.e., electric toothbrushes) as well as dental floss and interdental brushes significantly help remove plaque from dental surfaces including interproximal surfaces. In conclusion, modern concepts in caries prevention should focus not only on tooth remineralization alone but also on the control of all the key factors involved in caries development.

Characterization of crocodile teeth: correlation of composition, microstructure, and hardness.

Structure and composition of teeth of the saltwater crocodile Crocodylus porosus were characterized by several high-resolution analytical techniques. X-ray diffraction in combination with elemental analysis and infrared spectroscopy showed that the mineral phase of the teeth is a carbonated calcium-deficient nanocrystalline hydroxyapatite in all three tooth-constituting tissues: Dentin, enamel, and cementum. The fluoride content in the three tissues is very low (<0.1 wt.%) and comparable to that in human teeth. The mineral content of dentin, enamel, and cementum as determined by thermogravimetry is 71.3, 80.5, and 66.8 wt.%, respectively. Synchrotron X-ray microtomography showed the internal structure and allowed to visualize the degree of mineralization in dentin, enamel, and cementum. Virtual sections through the tooth and scanning electron micrographs showed that the enamel layer is comparably thin (100-200 µm). The crystallites in the enamel are oriented perpendicularly to the tooth surface. At the dentin-enamel-junction, the packing density of crystallites decreases, and the crystallites do not display an ordered structure as in the enamel. The microhardness was 0.60±0.05 GPa for dentin, 3.15±0.15 GPa for enamel, 0.26±0.08 GPa for cementum close to the crown, and 0.31±0.04 GPa for cementum close to the root margin. This can be explained with the different degree of mineralization of the different tissue types and is comparable with human teeth.

Clinical Evidence of Biomimetic Hydroxyapatite in Oral Care Products for Reducing Dentin Hypersensitivity: An Updated Systematic Review and Meta-Analysis.

Dentin hypersensitivity (DH) is a very common dental problem that can have a negative impact on the quality of life and can lead to invasive dental procedures. Prevention of DH and control of symptoms are highly desirable. Hydroxyapatite (HAP) has been shown in vitro to block dentinal tubules and in vivo to be a safe and effective additive in oral care products that reduce DH clinically. This study's aim was to conduct a systematic review and meta-analysis of the current evidence that HAP-containing oral care products reduce DH. Databases were searched, and only clinical trials in humans were included; studies conducted in vitro or on animals were not included. Publications in a foreign language were translated and included. We found 44 published clinical trials appropriate for systematic analysis. More than half of the trials had high-quality GRADE scores. HAP significantly reduced dentin hypersensitivity compared to placebo (39.5%; CI 95% [48.93; 30.06]), compared to fluoride (23%; CI 95% [34.18; 11.82]), and with a non-significant tendency compared to other desensitizing agents (10.2%; CI 95% [21.76; -19.26]). In conclusion, the meta-analysis showed that HAP added to oral care products is a more effective agent than fluoride in controlling dentin hypersensitivity and may be superior to other desensitizers.

Tooth Whitening with Hydroxyapatite: A Systematic Review.

A steadily increasing public demand for whiter teeth has resulted in the development of new oral care products for home use. Hydroxyapatite (HAP) is a new ingredient to whiten teeth. This systematic review focuses on the evidence of whether HAP can effectively whiten teeth. A systematic search using the PICO approach and PRISMA guidelines was conducted using PubMed, Scopus, Web of Science, SciFinder, and Google Scholar as databases. All study designs (in vitro, in vivo) and publications in foreign language studies were included. Of the 279 study titles that the searches produced, 17 studies met the inclusion criteria. A new "Quality Assessment Tool For In Vitro Studies" (the QUIN Tool) was used to determine the risk of bias of the 13 studies conducted in vitro. Moreover, 12 out of 13 studies had a low risk of bias. The in vivo studies were assigned Cochrane-based GRADE scores. The results in vitro and in vivo were consistent in the direction of showing a statistically significant whitening of enamel. The evidence from in vitro studies is rated overall as having a low risk of bias. The evidence from in vivo clinical trials is supported by modest clinical evidence based on six preliminary clinical trials. It can be concluded that the regular use of hydroxyapatite-containing oral care products effectively whitens teeth, but more clinical trials are required to support the preliminary in vivo evidence.

Improving Oral Health with Fluoride-Free Calcium-Phosphate-Based Biomimetic Toothpastes: An Update of the Clinical Evidence.

As the demand for clinically effective fluoride-free oral care products for consumers increases, it is important to document which types of toothpastes have been shown in clinical studies to be effective in improving oral health. In this review, we included different indications, i.e., caries prevention, improving periodontal health, reducing dentin hypersensitivity, protecting against dental erosion, and safely improving tooth whitening in defining what constitutes improvement in oral health. While there are several professional and consumer fluoride-containing formulations fortified with calcium-phosphate-based ingredients, this review focuses on fluoride-free toothpastes containing biomimetic calcium-phosphate-based molecules as the primary active ingredients. Several databases were searched, and only clinical trials in human subjects were included; in vitro and animal studies were excluded. There were 62 oral health clinical trials on biomimetic hydroxyapatite (HAP), 57 on casein phosphopeptide-amorphous calcium phosphate (CPP-ACP), 26 on calcium sodium phosphosilicate (CSPS, or so called Bioglass), and 2 on ß-tricalcium phosphate (ß-TCP). HAP formulations were tested the most in clinical trials for benefits in preventing caries, dentin hypersensitivity, improving periodontal health, and tooth whitening. Based on the current clinical evidence to date, fluoride-free HAP toothpaste formulations are the most versatile of the calcium phosphate active ingredients in toothpastes for improving oral health.

Influence of the Amount of Toothpaste on Cleaning Efficacy: An In Vitro Study.

OBJECTIVES: The aim of this in vitro study was to test the influence of the amount of toothpaste on enamel cleaning efficacy. MATERIALS AND METHODS: The hydrated silica-based test toothpaste (radioactive dentin abrasion: 60.19 ± 1.35) contained all ingredients of a regular fluoride toothpaste. The cleaning efficacy of four different toothpaste amounts (1.00 g, 0.50 g [both "full length of brush"], 0.25 g ["pea-size"], and 0.125 g ["grain of rice-size"]) diluted in 1.00 mL water were each tested for different brushing times (10, 30, 60, 120, 180, and 300 seconds) using a standardized staining model on human molars with a brushing machine. Photographic documentation and colorimetric measurements were conducted, respectively, initially, after staining and after each brushing step. Colorimetric measurements were used to calculate the stain removal (in %). STATISTICAL ANALYSIS: Results were analyzed by one-way analysis of variance with post hoc Tukey test and Levene's test for analysis of homogeneity of variance. The level of significance α was set at ≤ 0.05. RESULTS: The cleaning efficacy decreased significantly when using smaller toothpaste amounts. Stain removal after 120 seconds brushing time was: 77.4 ± 5.0% (1.00 g toothpaste), 75.7 ± 3.4% (0.50 g toothpaste), 54.1 ± 6.7% (0.25 g toothpaste), and 48.2 ± 7.1% (0.125 g toothpaste), respectively. CONCLUSION: In this in vitro study the cleaning efficacy of a medium-abrasive, hydrated silica-based toothpaste was analyzed. Note that 1.00 g toothpaste showed for all brushing times a significantly higher cleaning efficacy than 0.25 g toothpaste and 0.125 g toothpaste.

Toothpaste Abrasion and Abrasive Particle Content: Correlating High-Resolution Profilometric Analysis with Relative Dentin Abrasivity (RDA).

In this in vitro study, the influence of the concentration of abrasive particles on the abrasivity of toothpastes was investigated using laser scan profilometry on polymethyl methacrylate (PMMA) surfaces with the aim of providing an alternative method to developers for screening of new toothpaste formulations. PMMA plates were tested in a toothbrush simulator with distilled water and four model toothpastes with increasing content of hydrated silica (2.5, 5.0, 7.5, 10.0 wt%). The viscosity of the model toothpaste formulations was kept constant by means of varying the content of sodium carboxymethyl cellulose and water. The brushed surfaces were evaluated using laser scan profilometry at micrometer-scale resolutions, and the total volume of the introduced scratches was calculated along with the roughness parameters Ra, Rz and Rv. RDA measurements commissioned for the same toothpaste formulations were used to analyze the correlation between results obtained with the different methods. The same experimental procedure was applied to five commercially available toothpastes, and the results were evaluated against our model system. In addition, we characterize abrasive hydrated silica and discuss their effects on PMMA-sample surfaces. The results show that the abrasiveness of a model toothpaste increases with the weight percentage of hydrated silica. Increasing roughness parameter and volume loss values show good correlation with the likewise increasing corresponding RDA values for all model toothpastes, as well as commercial toothpastes without ingredients that can damage the used substrate PMMA. From our results, we deduce an abrasion classification that corresponds to the RDA classification established for marketed toothpastes.

Remineralization Strategies for Teeth with Molar Incisor Hypomineralization (MIH): A Literature Review.

Molar incisor hypomineralization (MIH) is a highly prevalent dental developmental disorder with a significant health burden for patients and high treatment needs, yet no comprehensive review article on all remineralization systems as a non-invasive treatment approach for MIH has been published. Typical characteristics of MIH-affected teeth are a lower mineral density and lower hardness compared to healthy teeth leading to sensitivity and loss of function. Thus, the use of formulations with calcium phosphates to remineralize MIH-affected teeth is reasonable. This review presents an up-to-date overview of remineralization studies focusing on active ingredients investigated for remineralization of MIH, i.e., casein phosphopeptide amorphous calcium phosphate (CPP-ACP), casein phosphopeptide amorphous calcium fluoride phosphate (CPP-ACFP), hydroxyapatite, calcium glycerophosphate, self-assembling peptide, and fluoride. Overall, 19 studies (in vitro, in situ, and in vivo) were found. Furthermore, an additional search for studies focusing on using toothpaste/dentifrices for MIH management resulted in six studies, where three studies were on remineralization and three on reduction of sensitivity. Overall, the studies analyzed in this review showed that MIH-affected teeth could be remineralized using calcium phosphate-based approaches. In conclusion, calcium phosphates like CPP-ACP, calcium glycerophosphate, and hydroxyapatite can be used to remineralize MIH-affected teeth. In addition to MIH-remineralization, CPP-ACP and hydroxyapatite also offer relief from MIH-associated tooth sensitivity.

The composition of the dental pellicle: an updated literature review.

Background: The dental pellicle is a thin layer of up to several hundred nm in thickness, covering the tooth surface. It is known to protect the teeth from acid attacks through its selective permeability and it is involved in the remineralization process of the teeth. It functions also as binding site and source of nutrients for bacteria and conditioning biofilm (foundation) for dental plaque formation. Methods: For this updated literature review, the PubMed database was searched for the dental pellicle and its composition. Results: The dental pellicle has been analyzed in the past years with various state-of-the art analytic techniques such as high-resolution microscopic techniques (e.g., scanning electron microscopy, atomic force microscopy), spectrophotometry, mass spectrometry, affinity chromatography, enzyme-linked immunosorbent assays (ELISA), and blotting-techniques (e.g., western blot). It consists of several different amino acids, proteins, and proteolytic protein fragments. Some studies also investigated other compounds of the pellicle, mainly fatty acids, and carbohydrates. Conclusions: The dental pellicle is composed mainly of different proteins, but also fatty acids, and carbohydrates. Analysis with state-of-the-art analytical techniques have uncovered mainly acidic proline-rich proteins, amylase, cystatin, immunoglobulins, lysozyme, and mucins as main proteins of the dental pellicle. The pellicle has protective properties for the teeth. Further research is necessary to gain more knowledge about the role of the pellicle in the tooth remineralization process.

Caries-preventing effect of a hydroxyapatite-toothpaste in adults: a 18-month double-blinded randomized clinical trial.

Background: Dental caries is a worldwide challenge for public health. The aim of this 18-month double-blinded, randomized, clinical trial was to compare the caries-preventing effect of a fluoride-free, hydroxyapatite toothpaste (test) and a toothpaste with sodium fluoride (1450 ppm fluoride; positive control) in adults. Methods: The primary endpoint was the percentage of subjects showing no increase in overall Decayed Missing Filled Surfaces (DMFS) index. The study was designed as non-inferiority trial. Non-inferiority was claimed if the upper limit of the exact one-sided 95% confidence interval for the difference of the primary endpoint DMFS between test and control toothpaste was less than the predefined margin of non-inferiority (Δ ≤ 20%). Results: In total, 189 adults were included in the intention-to-treat (ITT) analysis; 171 subjects finished the study per protocol (PP). According to the PP analysis, no increase in DMFS index was observed in 89.3% of subjects of the hydroxyapatite group and 87.4% of the subjects of the fluoride group. The hydroxyapatite toothpaste was not statistically inferior to a fluoride toothpaste with regard to the primary endpoint. Conclusion: Hydroxyapatite was proven to be a safe and efficient anticaries agent in oral care. Clinical trial registration: NCT04756557.

Structure, composition, and mechanical properties of shark teeth.

The teeth of two different shark species (Isurus oxyrinchus and Galeocerdo cuvier) and a geological fluoroapatite single crystal were structurally and chemically characterized. In contrast to dentin, enameloid showed sharp diffraction peaks which indicated a high crystallinity of the enameloid. The lattice parameters of enameloid were close to those of the geological fluoroapatite single crystal. The inorganic part of shark teeth consisted of fluoroapatite with a fluoride content in the enameloid of 3.1 wt.%, i.e., close to the fluoride content of the geological fluoroapatite single crystal (3.64 wt.%). Scanning electron micrographs showed that the crystals in enameloid were highly ordered with a special topological orientation (perpendicular towards the outside surface and parallel towards the center). By thermogravimetry, water, organic matrix, and biomineral in dentin and enameloid of both shark species were determined. Dentin had a higher content of water, organic matrix, and carbonate than enameloid but contained less fluoride. Nanoindentation and Vicker's microhardness tests showed that the enameloid of the shark teeth was approximately six times harder than the dentin. The hardness of shark teeth and human teeth was comparable, both for dentin and enamel/enameloid. In contrast, the geological fluoroapatite single crystal was much harder than both kinds of teeth due to the absence of an organic matrix. In summary, the different biological functions of the shark teeth ("tearing" for Isurus and "cutting" for Galeocerdo) are controlled by the different geometry and not by the chemical or crystallographic composition.

Prevention of Caries and Dental Erosion by Fluorides-A Critical Discussion Based on Physico-Chemical Data and Principles.

Dental erosion is a common problem in dentistry. It is defined as the loss of tooth mineral by the attack of acids that do not result from caries. From a physico-chemical point of view, the nature of the corroding acids only plays a minor role. A protective effect of fluorides, to prevent caries and dental erosion, is frequently claimed in the literature. The proposed modes of action of fluorides include, for example, the formation of an acid-resistant fluoride-rich surface layer and a fluoride-induced surface hardening of the tooth surface. We performed a comprehensive literature study on the available data on the interaction between fluoride and tooth surfaces (e.g., by toothpastes or mouthwashes). These data are discussed in the light of general chemical considerations on fluoride incorporation and the acid solubility of teeth. The analytical techniques available to address this question are presented and discussed with respect to their capabilities. In summary, the amount of fluoride that is incorporated into teeth is very low (a few µg mm-2), and is unlikely to protect a tooth against an attack by acids, be it from acidic agents (erosion) or from acid-producing cariogenic bacteria.

On the Application of Calcium Phosphate Micro- and Nanoparticles as Food Additive.

The human body needs calcium and phosphate as essential nutrients to grow bones and teeth, but they are also necessary for many other biochemical purposes (e.g., the biosynthesis of phospholipids, adenosine triphosphate, ATP, or DNA). The use of solid calcium phosphate in particle form as a food additive is reviewed and discussed in terms of bioavailability and its safety after ingestion. The fact that all calcium phosphates, such as hydroxyapatite and tricalcium phosphate, are soluble in the acidic environment of the stomach, regardless of the particle size or phase, means that they are present as dissolved ions after passing through the stomach. These dissolved ions cannot be distinguished from a mixture of calcium and phosphate ions that were ingested separately, e.g., from cheese or milk together with soft drinks or meat. Milk, including human breast milk, is a natural source of calcium and phosphate in which calcium phosphate is present as nanoscopic clusters (nanoparticles) inside casein (protein) micelles. It is concluded that calcium phosphates are generally safe as food additives, also in baby formula.

Overview on Adjunct Ingredients Used in Hydroxyapatite-Based Oral Care Products.

Hydroxyapatite, Ca5(PO4)3(OH), is a biomimetic active ingredient, which is used in commercial oral care products such as toothpastes and mouthwashes worldwide. Clinical studies (in vivo) as well as in situ and in vitro studies have shown the preventive effects of hydroxyapatite in various field of oral care. In some products, hydroxyapatite is combined with other active ingredients, to achieve an additional antibacterial effect or to promote gum health. This review analyzes the efficacy of six selected natural and nature-inspired ingredients that are commonly used together with hydroxyapatite. These additional actives are either antibacterial (lactoferrin, xylitol, and zinc) or promote gum health (allantoin, bisabolol, and hyaluronic acid). A systematic literature search was performed, and all studies found on each ingredient were analyzed. In summary, all analyzed ingredients mentioned in this review are well described in scientific studies on their beneficial effect for oral health and can be used to expand the preventive effect of hydroxyapatite in oral care products.