Calcium carbonate, 'armed' to the teeth

In recent years, the application of calcium carbonate in dentistry has garnered significant attention, particularly for its role in repairing tooth enamel. This application is based on the principle of mimicking natural biological self-healing processes to develop new biomaterials that can sense damage and repair themselves. Bio-mineralized dental self-healing resin composites have been developed and are being utilized in dental clinics. Dental resin composites are widely used due to their excellent aesthetics and good mechanical properties, but they are prone to accumulating micro-cracks due to factors such as masticatory forces and thermal stresses, especially in high-stress-bearing areas, which can lead to fractures in fillings and shorten their lifespan.

To address this challenge, developing crack-resistant composites is crucial for enhancing the durability of dental resin fillings. The Ninth People's Hospital, affiliated with Shanghai Jiao Tong University School of Medicine, has disclosed a bio-mineralized dental self-healing resin composite material and its preparation and application methods. This innovative composite material includes:

- Base resin

- Filler material

- Nutrient powder

- Bacterial powder

The bacterial powder contains bacteria selected from at least one of the following: Bacillus spp., Bifidobacterium longum, or Lactobacillus reuteri. The Bacillus spp. include at least one of Sphaerobacter sphaericus, Sphaerobacter lysiniformis, Bacillus licheniformis, Bacillus pasteurii, or Bacillus subtilis. The preparation method involves mixing the base resin, barium glass powder, nutrient powder, and bacterial powder, followed by light curing to obtain the final product.

Compared to existing technologies, this invention introduces bacteria capable of inducing calcium carbonate precipitation into dental resin composites. Through bio-mineralization, these materials achieve self-healing capabilities and can undergo multiple self-healing cycles. This advancement represents a significant step forward in improving the longevity and performance of dental restorations, leveraging the natural ability of certain bacteria to precipitate calcium carbonate and thereby promote the repair of micro-damages within the composite material.

This development not only enhances the physical properties of dental fillings but also integrates biological principles into material science, potentially leading to more durable and longer-lasting dental treatments.

A Preparation Method for Multicomponent Mineral Compounds

Multicomponent mineral compounds refer to compounds composed of two or more different mineral components. Due to the tunability of their chemical composition, these materials exhibit diverse chemical properties. However, traditional nucleation and growth theories limit the tendency of ions from different mineral components to form their respective critical nuclei first, making it challenging to achieve uniform mixing at the molecular scale between different mineral components. This poses a significant challenge in the preparation of multicomponent mineral compounds.

Zhejiang University has disclosed a method for preparing multicomponent mineral compounds, which includes:

1. Preparing calcium carbonate oligomers and calcium phosphate oligomers.

2. Uniformly mixing the calcium carbonate oligomers with the calcium phosphate oligomers, followed by stirring, centrifugal separation, washing, to obtain a composite gel of calcium carbonate and calcium phosphate.

3. Drying the composite gel of calcium carbonate and calcium phosphate to yield the multicomponent mineral compound.

The invention also discloses the multicomponent mineral compounds prepared by the aforementioned method and their applications. The preparation process is simple and cost-effective. The resulting multicomponent mineral compounds exhibit uniform structure at the molecular level, tunable chemical composition and properties, a single and adjustable phase transition temperature, and excellent mechanical performance. Their hardness can reach 0.85±0.08 GPa, which is 142% higher than that of amorphous calcium carbonate and 102% higher than that of amorphous calcium phosphate. These characteristics make the compounds promising for applications in cement fillers, bio-cements for bone, and dental restoration.

A Preparation Method for a Bioactive Mineral Material for Enamel Calcium Repair

Enamel is the only acellular tissue in the body, secreted by epithelial cells and subsequently mineralized; it has almost no capacity for self-repair after damage. Covering the surface of the tooth crown, enamel is the first tissue to be affected by dental caries. Guangxi Xinye Biotechnology Co., Ltd. has disclosed a preparation method for a bioactive mineral material designed for enamel calcium repair. This method consists of four steps: preparation of a pre-dissolution solution and a pre-dispersion solution, main ingredient mixing, adhesive preparation, and final product formation.

In the main ingredient mixing step, hydroxyapatite/egg yolk lecithin lyophilized powder, microcrystalline cellulose, and bioglass are used as primary ingredients, supplemented with calcium carbonate and silica. Through this inventive preparation method, a bioactive mineral material for enamel calcium repair is obtained that closely mimics natural enamel material. This material can effectively repair enamel and shows promising application potential.