Citation

Sayyed, A. Z., Patil, A. M., Patil, S. P., Sonawane, J. P., & Quazi, M. A. (2026). Physicochemical, Biological and Antibacterial Evaluation of Metal Oxide and Calcium Silicate Materials: A Comprehensive Review. International Journal of Research, 13(13), 11–31. https://doi.org/10.26643/ijr/2026/s13/2

Aarzoo Z. Sayyed¹, Arun M. Patil^1*, Sandip P. Patil², Jaywant P. Sonawane³, Mahewash A. Quazi¹

¹Department of Physics, R. C. Patel Arts, Commerce and Science College, Shirpur-425405, India

²Department of Microbiology and Biotechnology, R. C. Patel Arts, Commerce and Science College, Shirpur-425405, India

³Department of Chemistry, R. C. Patel Arts, Commerce and Science College, Shirpur-425405, India

^*Corresponding author: ampatil67@gmail.com

Abstract

Metal oxide and calcium silicate materials are largely utilized in the field of medicine and dentistry.

Some of the metals that are stable, bio-compatible, and antibacterial include zinc oxide (ZnO), titanium dioxide (TiO₂) and magnesium oxide (MgO). These are utilized in bone skeleton, tooth drugs, and self-cleaning surfaces. Calcium silicate materials, tricalcium silicate, dicalcium silicate are bioactive materials are used in regenerating bone tissue, repairing tissue and in dental procedures.This review will integrate and comment on research available regarding physicochemical, biological, and antibacterial properties of these materials. Physicochemical properties including the structure, thermal stability, funniness, and surface area relevant to the physical behavior of materials. Unlike the case of biological tests, which focus on the cytotoxicity, proliferation and bioactivity of cells, antibacterial tests can demonstrate the activity of such materials in relation to destructive bacteria.It is also proved in the available literature that both, metal oxides, and calcium silicates have quite promising biological and antibacterial activities, the particularities of their mechanism may vary depending on the particles size, new synthesis methods, and chemical formulations. Despite this, missing links in the in vivo studies, long term, standard testing and multifunctional optimization, are not covered. Bioactivity and antibacterial efficacy have to be improved and considered in clinical terms in the future.

Keywords: Metal Oxides, Calcium Silicate, Physicochemical Properties, Biological Evaluation, Antibacterial Properties

1. Introduction

Background and Significance

Metal oxides and calcium silicate materials have been granted extensive consideration over the recent years because of its uniqueness and number of usabilities. Metal oxides include zinc oxide (ZnO), titanium dioxide (TiO₂) and magnesium oxide (MgO) and are chemically stable, biocompatible and antibacterial. The noted behaviors qualify it as usable in biomedical applications, environmental remediation and engineering materials. In biomedical applications, bioactive ceramics (calcium silicate compounds) such as tricalcium silicate (3CaOSiO₂) and dicalcium silicate (2CaOSiO₂) can be integrated (El Nahrawy et al., 2021). They are capable of offering bone and tissue repair as well as bone regeneration and are extensively applied in the US in oral applications as well as orthopedic applications.

These are multi-purpose materials since they have favorable physicochemical properties, including particle size, surface area, crystallinity, and heat stability. Apart from their biological and antibacterial property compatibility, it is very key to medical and dental efficacy and safety. This research may allow the research scholar and engineers to build materials that are robust and stable and promote healing and eliminate infection.

Applications

• Bonescafs, orthopaedic devices, closure of wounds, transdermal devices,
• Dentistry: tooth filling materials, restoration materials for teeth, tooth resin, sealants for teeth, tooth restoration systems.
• Engineering Catalysts, sensors, coats of arms, environmental clean-up material.

Importance of Evaluation

• The assessment of physicochemical and biological and antibacterial properties is an integral part of determining the yield of such materials.
• Physicochemical analysis applies in the assessment of structure, composition, surface and stability (Fosca et al., 2023).
• Biologic testing of materials provides protection for cells and tissue in that it aids in facilitating attachment of cells, proliferating, and differentiating.
• An antibacterial test is run in order to determine if materials have infection prevention capabilities and is of great relevance to implants and dental applications.

Aim and Objectives of the Review

This literature review report endeavours to compile as much as possible of the work that is available on metal oxides and calcium silicate materials and their application pertaining to physicochemical, biological, and antibacterial characteristics. It will critically survey existing literature, spurred either by trends or defining major conclusions.

Objectives

• To discuss the physicochemical characteristics of the material metals oxide such as the structural, surfaces, chemical, thermal and mechanical properties.
• To analyze the biological performance of this type of materials, it will be necessary to concentrate on the biological performance playing such materials i.e., the biocompatibility and bioactivity and also interactions of the cell of tissues.
• To study dynamic action and efficacy of metal oxides and calcium silicates as the antibacterials on the basis of available publications of laboratory and clinical studies.
• To formulate the said gaps in the research and the direction to follow in creating the multi-functional properties as well as to determine the potential application in the medical field, field of dentistry with the aid of the field of tissue engineering.

Scope of the Review

• Properties and classifications of metal oxides materials and calcium silicate.
• Biological activity, such as cytotoxicity, cell adhesion and bioactivity. Antibacterial motions and actions against different types of bacteria.
• Synthesis processes and their impact on materials.
• Applications in clinical and industry, gaps in research and future perspective.

Figure 1:Schematic overview of metal oxide and calcium silicate applications in biomedical fields(Source:Al-Naymi et al., 2024)

2. Classification of Materials

Metal Oxides

Metal oxides are compounds of metal elements and oxygen. They are very stable, bioactive, and antibacterial compounds. The following are some of the major ones among them.

Zinc Oxide (ZnO):

It possesses excellent antibacterial activity, high stability, and is popularly applied in medical coatings, wound care, and dental materials (Jang et al., 2023). Due to the nanosized nature, it is capable of forming reactive oxygen species (ROS) that destroy bacteria.

Titanium Dioxide (TiO₂):

It is biocompatible and is often used in medical devices and dental applications. It is also photocatalytic, that is, it is light-reactive and leads to antibacterial activity.

Magnesium Oxide (MgO):

MgO is stable at temperatures and is safe for biological usage. It encourages bone growth and is studied as an alternative bone graft and scaffold enhancer.

Copper Oxide (CuO):

CuO is highly antibacterial. It is used as a coating as well as sensor material, but cytotoxicity at higher doses prevents direct medical application.

Calcium Silicate Materials

Calcium silicate compounds are bioactive ceramics with positive interactions with body tissue. They encourage attachment and restoration of bone and tooth (Janini et al., 2021).

Tricalcium Silicate (3CaO·SiO₂):

It is widely applied in root canal sealers and dental cements. It promotes bioactivity and hydroxyapatite formation when it comes into contact with body fluids and aids bone regeneration.

Dicalcium Silicate (2CaO·SiO₂):

Typical for a slower working setting reaction, it is bioactive as well and helps establish strong bonds with tissue.

Wollastonite

It is a natural calcium silicate and is very much biocompatible. The compound is normally introduced into bone tissue engineering as it supports growth and mineralization of cells.

Table 1:Comparison of Metal Oxides and Calcium Silicate Materials

Material	Chemical Formula	Crystal Structure	Key Property	Application
ZnO	ZnO	Hexagonal	Antibacterial, UV absorption	Bone scaffold, coatings
TiO₂	TiO₂	Rutile/Anatase	Photocatalytic, Biocompatible	Dental cement, coatings
MgO	MgO	Cubic	High thermal stability	Bone graft
Tricalcium Silicate	3CaO·SiO₂	Monoclinic	Bioactive, osteogenic	Cement, scaffolds

3. Physicochemical Properties

Structural Analysis (XRD, SEM, TEM)

Composition of materials is very important as it dictates the type of material as it is in application. The researchers are conversant with the application of the X-ray diffraction (XRD), scanning electron microscopy (SEM), and transaction electron microscopy (TEM) in its study.

The phase and crystal structure is also acquired by use of X-ray diffraction (XRD). For example, hexagonal wurtzite XRD pattern can generally be ZnO; and TiO₂ rutile or anatase. The presence of either the monoclinic or the orthorhombic crystalline phase will be established in the presence of tricalcium silicate compounds such as tricalcium silicate. This will help determine level of material stability, and whether the material would retain the properties of the biological temperature.

When analyzing the surface morphology of the particles, one applies scan electron microscopy. It gives the data regarding the nature and the sizes of the crystals/grains (Jin and Jin, 2021). The calcium silicate would be porous and irregular when the zinc oxide nano -particles are spherical or rod shaped. The morphology is a factor that weighs a lot to check the reactivity of the surface or biological connection.

Next in line to electron microscopy is Repastephanou (1998) Transmission electron microscopy (TEM) that gives us the images of the internal structure of such thing as patterns of lattices in very high resolution. It can now be tested together with TEM in order to discover the dimension of the a particles at the nano scale and rediscoveries which can now be made on the defects, crystallinity and grains. This is good as the enhanced activities and functions with regards to the antibacterial and biological portions are observed with tiny and shrunken measurement and size of the particles.

The likelihood of coming up with a complete set of description of what materials accumulate at the nano level and at the micro level also exists when all the three methods are employed.

Recovery.

Definitive definition of the nature interaction of the material to the exterior environment is made on the surface of the material e.g., the biological cells and fluids of the bacteria. Surface parameters best comprehended are the surface area, porosity, and hydrophilicity.

Surface area is crucial as increased surface area allows for increased exposure for cell, protein, and bacterial interactions. These ZnO and TiO₂ nanoparticles also possess very extensive surface areas and are hence superior in antibacterial activity and bioactivity. In a similar vein, porous calcium silicate materials possess an extensive surface on which apatite formation induces attachment with bone.

Porosity is defined as the existence of pores or tiny holes throughout the material. High porosity materials are capable of fluid penetration and ion exchange (Khan et al., 2023). In biomedical applications, porosity aids in cell migration and nutrient transport, a concern in tissue engineering. Interconnected porosity is specifically sought after in calcium silicates with future bone tissue development in mind.

The hydrophilicity is the ability of the material to attract water. Cell spreading as well as cell adhesion is increased with the hydrophilic surfaces because hydrophilic surfaces are closer to the natural biological environment. There are a variety of metal oxides that are hydrophilic, e.g., TiO₂, and surface treatments are applied in calcium silicate-based materials with the objective of increasing hydrophilicity.

Overall, the surface nature primarily decides the adhesiveness of such materials with tissue as well as the efficiency of such materials in antibacterial application.

Chemical Properties (Elemental Composition, Stability under pH and Temperature)

Chemical properties establish the constitution and the stability of materials. Scientists can employ energy dispersive spectroscopy (EDS) or inductively coupled plasma (ICP) techniques in order to establish the elemental composition.

Composition of elements ensures that the materials are chemically pure and are without harmful impurities. For example, ZnO needs to contain zinc and oxygen in definite proportions without other elements capable of causing toxicity.Similarly, calcium silicates need to contain calcium and silicon in definite proportions so as to maintain their bioactive potential.  Stability against pH conditions is equally important. The body itself is weakly alkaline with pH near 7.4 but localized sites, e.g., infection sites or sites of wound, are acidic (Majeed et al., 2023). A stable material will not degrade too rapidly in acidic and alkaline conditions. Metal oxides, e.g., TiO₂, are highly stable against a very wide pH range, while calcium silicates degrade very slowly and give out calcium and silicate ions. This slow ion release is actually beneficial for bone and tissue regeneration.

Thermal stability of chemical nature is the degree it resists breakdown with increase of temperature. In biomedical application, the materials need to maintain their constitution while undergoing sterilization, usually a method of using high temperatures. The thermal stability of ZnO is up about 800°C and that of tricalcium silicate even higher.

In general, chemical stability and composition ensure materials are functional and safe in application usage.

Thermal and Mechanical Properties (Thermal Stability, Compressive Strength, Hardness)

Mechanical and thermal are quite basic physical characteristics needed for materials used in engineering, orthopedics, as well as in dentistry. They determine the toughness and strength of materials resisting pressure and changing temperatures.Thermal stability is defined as the capacity of the material not to experience breakdown upon increased temperatures. Both MgO and TiO₂, for instance, are attributed with very good thermal stability and hence are applied in operations such as processing and sterilization at increased temperatures. Calcium silicates are also attributed with very good thermal stability and hence applied in bone cements and bioactive coatings that require heat application while being prepared.

Compressive strength is a measure of the pressure it will withstand until it will fail. It is a desirable specification for orthopedic and dental materials required to bear body weight or chewing forces. Compressive strength is normally adequate for silicate cements, and it is maximized while the cement is setting up and maturing (Negrescu et al., 2022). Metal oxides used as fillers may provide added strength and durability. Hardness is one of the specifications undoubtedly indispensable and is quantified as the degree of resistance against scratch or indentation on the material. To enhance wear resistance, some of the natural hard minerals, e.g., TiO₂ and ZnO are added to the composites. The components of the calcium silicate render the substance less tough and strong.They are developed to be stubborn to leave the body and to perform their work without being easily defamed.

It is due to the effect of physicochemical factors that the reaction of calcium silicate material and metal oxide materials to change in the environmental conditions occurs. Material physicochemical qualities depend on surface property, chemical stability, thermal and mechanical strength. Analytical methods including XRD, SEM, and TEM may investigate particle morphology inside and out. They respond to cells and bacteria based on surface area, porosity, and hydrophilicity. Safety and dependability depend on stability and chemical composition, whereas power and durability depend on mechanical and thermal factors.

With a study of all of these properties, researchers are capable of designing materials that are not merely hard and stable but are safe for biological usage and antibacterial performance. These are then highly sought after for medical, dental, and engineering purposes.

Figure 2:SEM/TEM images of ZnO nanoparticles and calcium silicate particles (Source: Algadi et al., 2025)

Table 2:Physicochemical properties of selected metal oxides and calcium silicate materials

Material	Particle Size (nm)	Surface Area (m²/g)	Porosity (%)	Thermal Stability (oC)
ZnO	50–100	25	15	800
TiO₂	20–50	50	10	900
MgO	30–60	40	12	1100
3CaO·SiO₂	100–200	30	20	1300

4. Biological Evaluation

Biocompatibility:

Biocompatibility is one of the conditions essential for every and all materials that are placed inside the human body. It simply means that the material is not required to be poisonous to the living cells or tissue with which it is in contact. For metal oxides such as zinc oxide (ZnO), titanium dioxide (TiO₂), and magnesium oxide (MgO) materials, a number of research have found that, in controlled concentrations, the materials are non-cytotoxic for the majority of mammalian cells. However, if the dose is excessive, some of them are capable of inducing cytotoxicity, e.g., retardation of cell growth or disruption of cell membranes. Researchers therefore extensively study the dose-dependent action of such materials.

Materials that contain calcium silicate, such as tricalcium silicate and dicalcium silicate, are normally very biocompatible (Mokhtar et al., 2023). This is because the materials have the capability of releasing calcium ions, which are endogenous in the human body and are needed in many biological functions. The ions improve cell survival and encourage healing. Hemocompatibility is also an integral part of biocompatibility. It is the property where the material should not kill the cells in the blood nor develop problems in clotting after exposing it to the blood. It is clear that calcium silicate cement and properly prepared metal oxides are normally very hemocompatible and are thus safe for usage in medicine and dental fields.

Bioactivity: Capacity for Apatite Formation

Bioactivity is the ability of a material to interact favorably with biological systems. The development of a hydroxyapatite layer on the surface after immersion in body-like fluids is one of the better indicators of bioactivity. Hydroxyapatite is the mineral that constitutes most of human bone and tooth. Tricalcium silicate and wollastonite are materials that form apatite crystals after contact with body fluids. It is an indication that the material is capable of binding strongly with tissue near it after implantation inside the body.Metal oxides are also bioactive, although with a somewhat different mechanism (Salem et al., 2022). For example, ZnO nanoparticles can stimulate the formation of mineralized tissue through the release of zinc ions, and zinc ions have very crucial roles in bone metabolism. Titanium dioxide is also very bioactive as it readily produces a bioactive surface layer and stimulates bone growth.

Osteogenic potential is the ability of a material to induce bone-forming cells (osteoblasts) and enable them to grow and divide and also deposit bone tissue. Osteogenic potential is highly established in calcium silicate cements. They are capable of releasing calcium ions, and the calcium ions induce osteoblastic activity and stimulate new bone formation. Titanium-bearing metal oxides are also widely used in orthopedic and dental applications as they are capable of bone regeneration.

Cell-Material Interaction: Adhesion, Prol

In order to work effectively within the body, the biomaterial must allow cells to adhere on the surface and respond positively to it. This is cell adhesion. After cells adhere, they must proliferate, i.e., divide and spread out across the surface of the material. Finally, cells must differentiate, i.e., develop their specialty functions like bone-forming cells, connective tissue cells, and so on, based on the application.

Metal oxides like TiO₂ are very good substrates for cell attachment. The rough and hydrophilic nature of TiO₂ promotes fast attachment of cells.In addition, calcium silicate materials promote secure attachment as a result of forming calcium and silicon ions with cell-signaling potential (Sharifi et al., 2024).Cells multiply well on calcium silicate cement, according to studies. Magnesium is essential for cell metabolism, and MgO and other metal oxides accelerate cell growth. In addition, differentiation is important for tissue rejuvenation. Stem cells exposed to calcium silicate materials become osteoblasts. This illustrates that method. Bone tissue engineering benefits greatly from this.

Animal Studies: Preclinical Implantation Results

Any new biomaterial intended for human implant is initially tested on animals to assure a positive response. Preclinical testing is crucial because it uses biological circumstances that are hard to replicate in a tissue culture dish.The use of metal oxides and final test in calcium silicates has been quite promising. Assuming that of much of the animals, such as dogs, rabbits, Titanium dioxide-covered material or substance can implant on that bone in a highly wonderful way and influence the tissue even without the undesirable reaction. In the same case, ZnO nanoparticles incorporated into dressing materials for wounds have been seen in animals as having rapid closure of wounds and reduced infection rates (Simila & Boccaccini, 2023). It is therefore suggested that metal oxides can serve as structural as well as antibacterial materials that promote healing.

Calcium silicate materials, after implantation inside bone defects of animals such as sheep, rabbits, and rats, have demonstrated strong bone regeneration. They not only filled and repaired the defects but also integrated adhesively with host bone tissue. Various research showcased that calcium silicate cements encouraged new blood vessels (angiogenesis) as much as required for long-term repair.  Results of the in vivo studies confirm that metal oxides and calcium silicate materials are safe, effective, and promising materials for potential application in the field of medicine, dentistry, and tissue engineering. These materials demonstrate very good biological compatibility, promote healing, and suppress infection. However, there is a need for extended studies on their long-term performance and potential toxicity before scale-up application in human subjects.

Figure 3:Illustration of cell adhesion and proliferation on metal oxide and calcium silicate surfaces(Source: Chang et al., 2022)

Table 3:Biological evaluation summary

Material	Cytotoxicity (IC50)	Bioactivity Score	Cell Adhesion	In Vivo Results
ZnO	80 μg/mL	High	Good	Positive bone integration
TiO₂	>100 μg/mL	Moderate	Excellent	Minimal inflammation
MgO	60 μg/mL	Moderate	Moderate	Partial osteogenesis
3CaO·SiO₂	50 μg/mL	High	Excellent	Strong bone regeneration

5. Antibacterial Evaluation

Mechanisms: ROS Generation, Membrane Disruption, Ion Release

Antibacterial action of biomedical materials is very important as it avoids infection upon placement of materials in the body. Metal oxides and calcium silicate materials kill or slow down the development of bacteria through certain primary mechanisms. Among the most common ones is the formation of reactive oxygen molecules (ROS). ROS are very reactive molecules, including hydroxyl and superoxide ions that are able to kill the protein, lipids, and DNA of bacteria (Al-Naymi et al., 2024). For example, ZnO and TiO₂ are highly described in the literature as forming ROS upon irradiation with light, killing the cells of bacteria.

Disruption of the membrane is another mechanism. Most metal oxide nanoparticles have charged surfaces and are able to adhere to the negatively charged bacterial cell walls. It disrupts the functioning of the bacterial membrane, forms holes, and leads to cell material leakage and subsequent cell death.

The third action is the liberation of ions. When metal oxides like ZnO or calcium silicates are brought into a moist atmosphere, they are liberated as ions in the forms of Zn²⁺, Ca²⁺, and Si⁴⁺. These ions disrupt the normal metabolism of the bacteria, prevent their enzyme activity, and do not allow them to divide. The calcium ions also increase the pH of the medium around the material and create an unfavorable environment for the survival of the bacteria. These combined roles make metal oxides and calcium silicate materials perfect antibacterial materials.

Tests: Agar Diffusion, MIC, Biofilm

To determine antibacterial activity, researchers utilize a variety of common lab assays. Perhaps the oldest and simplest is the agar diffusion test. The test is carried out by culturing the bacteria on an agar plate and placing the test compound on top. The compound will grow a clear zone around it if it is capable of antibacterial activity and there will be an absence of bacterial growth. The size of the zone is a measure of the effectiveness of the compound.

The other notable test is the Minimum Inhibitory Concentration (MIC) test. It measures the lowest amount of substance (or ions released) that is able to prevent growth in bacteria. It is a better indicator than agar diffusion and is valuable in comparing materials with differing strength.  Inhibition testing of biofilm is no less important (Algadi et al., 2025). Biofilms are aggregates of bacteria that stick to each other and form a protective film over the surface, enhancing resistance against antibiotics. The majority of medical and dental infections are caused by biofilms. They have also been proven very capable of preventing the formation of biofilms or breaking down formed biofilms, a significant plus factor in clinical usage.

Comparative Analysis Between Metal Oxides and Calcium Silicate

Both metal oxides and calcium silicate materials are very antibacterial, but both mechanisms and advantages are somewhat different. Metal oxides such as ZnO, TiO₂, and CuO are very capable of forming ROS and killing the bacteria directly. They are very powerful against a wide range of bacteria, even resistant ones. However, at very concentrated levels, some metal oxides might be cytotoxic against human cells, so careful control of dose is necessitated.

In contrast, calcium silicate materials are antibacterial as well as highly bioactive and biocompatible. Ion release and vigorous alkalinity are their major antibacterial activity. An undesirable growth condition for the bacteria is established as an outcome (Chang et al., 2022). Compared with metal oxides, the materials are less poisonous to human cells while improving tissue healing as an added benefit.

In layman’s terms, metal oxides are highly lethal materials with very strict control requirements, whereas calcium silicates are weak but very effective long-term materials as they trigger antibacterial activity and encourage bone and tissue growth. For the majority of biomedical applications, researchers are now looking at combinations of metal oxides with calcium silicate cements in an attempt to achieve the best of both worlds: strong antibacterial activity with very good tissue compatibility.

Figure 4:Antibacterial mechanism schematic (ROS generation and bacterial membrane damage)Source: (Chaudhari et al., 2022)

Table 4:Antibacterial activity against common bacteria

Material	Gram-Positive Bacteria	Gram-Negative Bacteria	MIC (μg/mL)	Biofilm Inhibition (%)
ZnO	S. aureus– High	E. coli– Moderate	50	75
TiO₂	S. aureus– Moderate	E. coli– Low	100	50
MgO	S. aureus– Low	E. coli– Low	80	40
3CaO·SiO₂	S. aureus– Moderate	E. coli– Low	60	60

 

6. Synthesis Methods and Influence

The fabrication method of metal oxides and calcium silicate materials vastly contributes final properties, and there are quite popular techniques of synthesis such as sol-gel, hydrothermal, co-precipitation, and solid-state reaction. Sol-gel is a popular technique due to very accurate control over particle size along with very uniform and nano-scale powders with greater surface area, improving bioactivity and antibacterial activity. Hydrothermal technique utilizes higher pressure and temperature with closed conditions in order to grow crystals with greater purity and controlled morphologies and frequently ends up with needle-shaped or rod-shaped particles improving cell attachment and reactivity across the surface. The co-precipitation technique is a facile and cost-effective one, where differing ions are co-precipitated at the same time from a medium, and it is advantageous in the scenario of large-scale fabrication of the material, but sometimes the final product might be less uniform unless very much controlled.  In the case of the solid-state technique, the powders are blended and sintered at higher temperatures in an attempt to achieve the desired material and while one of the most stable and uncomplicated compound-producing methods, product particle size is relatively large with less surface area compared to the sol-gel and hydrothermal technique.

Each of these methods affects particle size, shape, and crystallinity, which are crucial for biological applications. Smaller particles with increased surface area spread ions better, making them more powerful against germs. Controlling crystallinity stabilizes biological environments. Morphological differences like rods and spheres affect the cell’s shape and interaction with the bacterium. Adjusting temperature, pH, reaction time, and adding magnesium, zinc, and silver ions optimizes results. These ensure the best mechanical strength, bioactivity, and antibacterial qualities in manufactured materials. Silver ions can be added to calcium silicate to make it more antibacterial without affecting its biomaterial characteristics. Altering pH during sol-gel synthesis produces stable nanoparticles that form apatite better. Selecting the best material synthesis process and carefully controlling reaction conditions are the best ways to create stable, durable, bioactive, and microorganism-resistant materials. This makes them ideal for advanced medical, dental, and tissue engineering applications.

Figure 5:Flow diagram of different synthesis methods and their influence on material properties (Source: Ebenezer et al., 2025)

7. Applications

Metal oxides and calcium silicate materials have been subject to extensive research due to the potential number of applications, specifically biomedical application. They are regularly integrated in bone scaffolds as they encourage bone growth, strengthen, and adhere with host tissue. In dental cements, calcium silicate is highly desirable as it unleashes calcium ions that encourage tooth restoration, sealing, and long-term stability. These materials are also being studied for medicinal delivery systems. Because of their porosity, they can store and release drugs gradually at treatment sites, improving efficacy. Tissue engineering experts believe that metal oxides and calcium silicates heal wounded tissues best. These materials allow cells to proliferate, attach, and differentiate due to their surfaces (Ebenezer et al., 2020). Antibacterial coatings for implanted medical devices and wound dressings are also made from them. They produce reactive oxygen species and release ions to kill harmful germs and prevent infections. They are used in catalysis to speed chemical reactions and sensors since their surface is more reactive to their surroundings outside of medicine. Their chemical stability, germ-killing capabilities, and bioactivity make them valuable materials for pharmaceuticals, dental care, and technology.

8. Research gaps and problems

Calcium silicate and metal oxide research has been promising. However, numerous major issues must be addressed before this may be fully implemented in clinical settings. Many studies currently show intriguing antibacterial, bioactive, and cell compatibility. Short-term lab trials showed all of these. A much smaller number show long-term consequences in live organisms. Long-term research is valuable because it can show whether a substance can maintain stability, retain its antibacterial properties, and benefit tissue without side effects. Testing methods are also inconsistent. It is difficult to draw conclusions because different study groups may utilize different methods to test for bioactivity, cytotoxicity, or antibacterial potential. Ebenezer et al. (2025) found that standards would improve findings and allow them to be used in real medicine. Increasing materials’ multifunctionality is also important to preserve bioactivity and antibacterial efficacy. You must remember that increasing antibacterial characteristics can decrease biocompatibility while choosing the optimum blend. To better therapeutic use, more work is needed to develop secure, sturdy, multifunctional materials.

9. Future Research 

Future study on metal oxides and calcium silicates may focus on mixed or doped materials. Doping with small amounts of silver, zinc, magnesium, or copper boosts antibacterial activity while retaining biocompatibility. Doped or hybrid materials allow you to regulate particle size, surface charge, and ion release, as well as their internal effects. Physicochemical and biological improvement is the second method (El Nahrawy et al., 2021). This boosts the surface material’s strength, stability, and performance while promoting cell growth, bone mending, and infection prevention. Balance is maintained through synthesis chemistry and mix fine-tuning.Third, clinical translation of the materials is being executed. Preclinical work completed in the lab and animals is very promising but additions of clinical trials and safety determinations must be performed before it is used extensively throughout patients. In case such challenges are overcome, hybrid and multifunctional versions of the materials may have a very large application base in dentistry, orthopedics, wound care, and other clinical applications.

10. Conclusion

Metal oxides and calcium silicate materials have certain properties that are biologically active and antimicrobial in nature. They are thus used in biomedical applications.

Particle sizes are controlled. They are of huge surface area, with favorable crystallinity, and thermal and mechanical stability ensure resistivity. They are biocompatible, support attachment and harbor cell growth, differentiation and induce bone and tissue regeneration. In consideration of study, there exist some agents that kill or prevent breeding of bacteria through the formation of reactive oxygen molecules, pinching of cell membrane and ion releasing. Metal oxides of ZnO, TiO₂ and CuO are more efficacious antimicrobial. However, efficacy is reserved with appropriate dosing as elevated level of concentration leads to cytotoxicity. Conversely, bioactive and biocompatible silicates such as tricalcium silicate or wollastonite are better. Additionally, they exhibit an antibacterial activity via ion releasing and alkalinity. Furthermore, the other two appear to rebuild tissue. In spite of exemplary profiles, study gaps remain. They are long-term studies carried out in vivo and protocols capable of being classified as standardized. We also should develop metamaterials and such should possess best-possible bioactivity and ultimate antibacterial activity. We need future research work including next-generation hybrid or doped materials that harbor physicochemical and biological optimisation amenable for safe and efficacious clinical translation into medicine, dentistry and tissue engineering applications.

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