Materials with polymer bases called composite resins are utilized in dentistry to provide aesthetic repairs. They are created through the process of free radical polymerization, which in today's materials is started by visible light. Bulky, viscous monomers react to form an organic matrix that is resilient and long-lasting in therapeutic use. Although not perfect, properties are significantly enhanced by the addition of finely ground inorganic powders, such as barium silicate glasses. To enable the completed products to release fluoride in the mouth, fluoride salts can be added.
The therapeutic applications for composites in tooth restoration are numerous. However, for bulk filling, there are issues with curing thick layers of material, hence these materials are often used by adding layers one at a time. Since composite resins do not adhere, they must be used in conjunction with certain bonding agents to ensure fixation on the tooth surface.
What exactly composite resins are?
Dental cement composed of synthetic resins is known as composite resins, often known as "resin-based composites" or simply "filled resins." Based on their insoluble nature, good tooth-like appearance, ease of manipulation, insensitivity to dehydration, and low cost, synthetic resins have evolved into restorative materials.
Bis-GMA and other dimethacrylate monomers (TEGMA, UDMA, HDDMA), a filler substance such as silica, and in most applications, a photoinitiator forms the majority of composite resins. Dimethylglyoxime is frequently added to produce specific physical qualities including flow-ability. By creating special concentrations of each constituent, physical attributes can be further modified.
Numerous studies have contrasted the shorter lifetime of silver-mercury amalgam restorations to that of resin-based composite restorations. Composite restorations may last as long as amalgam restorations, depending on the dentist's expertise, the patient's individual traits, the kind of damage, and where it is located. Restorations made on resin-based composite have much better appearances than amalgam.
Advantages of Composite Resins
Composite resin offers several advantages and can be used in numerous applications as mentioned below.
1. Appearance:
Improved tooth tissue mimicking is a direct dental composite's key benefit over conventional materials such as amalgam. Composites are available in a variety of tooth hues, making tooth replacement almost unnoticeable. The color of existing teeth can be closely matched by composite fillings. The anterior tooth region is particularly important for appearance.
2. Bonding to tooth structure:
The tooth structure and composite fillings are mechanically micro-bonded. By doing this, the tooth's structure is strengthened and its natural physical integrity is maintained. The development of acid etching of teeth to create a micro-mechanical bond with the tooth has made it possible for restorations to adhere to teeth well. Dentin bonding chemicals can produce very strong bonds to tooth structure, including enamel and dentin.
3. A less expensive and more common replacement for dental crowns:
A composite restoration may be suggested as a less expensive (but probably less long-lasting) alternative to a dental crown in specific circumstances. In order for the dental crown to fit over or into the natural tooth, large amounts of healthy tooth material must typically be removed during installation. More of the natural tooth is preserved with composite restoration.
4. Versatility:
Teeth that have been cracked, damaged, or worn down can be restored with composite fillings rather than amalgam fillings.
5. Repairability:
A composite filling can often be easily repaired when it sustains slight damage by adding more composite. It may be necessary to completely replace an amalgam filling.
6. Longer working time:
In some ways, compared to amalgam restoration, the light-curing composite enables the operator to work on demand and for longer periods of time.
7. Reduced mercury emissions into the environment:
Composites prevent the environmental contamination of mercury caused by dentistry. Some mercury-containing amalgam is unavoidably flushed down drains when amalgam fillings are drilled for height adjustment, repair, or replacement.
When dentists make amalgam fillings, poorly disposed of extra material may end up in landfills or be burned. When bodies with amalgam fillings are cremated, mercury is released into the environment.
8. Lack of corrosion:
Resin composites do not corrode at all, despite the fact that corrosion is no longer a significant issue with amalgam fillings.
Future Insights on Composite Resin
In light of the aforementioned elements, it is clear that dental composite materials are a complicated system due to material-related elements affecting their physical, mechanical, and chemical characteristics to meet the clinical requirements inside the challenging oral environment circumstances.
Additionally, a variety of desired properties for their applications are anticipated for dental composites. However, the improvement of certain qualities may conflict with one another negatively, which makes the creation of optimum dental composite formulas more challenging.