Cimentos de Ionômero de Vidro - Composição, Indicações e Reação de Presa

Summary

This video addresses common questions about glass ionomer cement (GIC), a versatile dental material used for a variety of purposes including fillings, crowns, and restorations. The video covers GIC's long-term performance, its indications for both temporary and permanent use, and its clinical success. It also delves into its composition, comparing conventional GIC to resin-modified versions, highlighting their advantages and limitations. The script discusses key factors like retention, aesthetics, and mechanical properties, as well as the chemical processes involved in the material’s adhesion to dental structures. Finally, the video touches on its use in both primary and permanent restorations.

Takeaways

• 😀 The script focuses on addressing common questions about glass ionomer cement (GIC), especially its long-term use in dental restorations.
• 😀 GIC is commonly used for various dental procedures, such as fissure sealing, core build-ups, perforation filling, cervical resorption cases, and cementation of strategic pieces.
• 😀 Most indications of GIC are considered definitive restorations, meaning they are not intended to be replaced quickly after application.
• 😀 Studies show that restorations using GIC have good long-term survival rates, with 87% survival for single-surface restorations and 58% for multi-surface ones after 10 years.
• 😀 GIC is considered viable for restoring deciduous teeth, with clinical performance being similar to that of dental amalgam over a 3-year period.
• 😀 The main failure of GIC restorations is partial loss due to the material’s low flexural strength and poor retention in some cavity preparations.
• 😀 Systematic reviews indicate that GIC performs similarly to two-step adhesive systems in terms of retention when used for non-caries lesions.
• 😀 While GIC is clinically effective, it has some drawbacks, including inferior aesthetics, lower polishability, color stability, and resistance to wear compared to composite resins.
• 😀 GIC consists of a powder (aluminum silicate glass) and a liquid (typically an aqueous solution of polyacrylic acid), which together undergo an acid-base reaction.
• 😀 Modified GICs, which include resins, have improved properties, such as higher strength, increased working time, and reduced sensitivity to moisture.
• 😀 GIC's setting reaction involves an acid-base interaction, where glass powder releases calcium ions, which then react with the polyacrylic acid to form a gel, resulting in the final hardened material.

Q & A

What is glass ionomer cement (GIC) commonly used for in dental procedures?

Glass ionomer cement (GIC) is commonly used for dental applications such as sealants for photo and fissures, filling perforations, restorations (both temporary and permanent), treatment of external resorption (especially in cervical regions), lining, and cementing strategic pieces and bands.

How does the long-term performance of GIC restorations compare to other materials?

Studies have shown that GIC restorations have an excellent survival rate, with one-face restorations showing a survival rate of 87% after ten years. However, restorations with multiple faces had a lower survival rate of 58%, indicating that GIC performs well in single-surface restorations.

What are the primary causes of failure in GIC restorations?

The most common cause of failure in GIC restorations is the loss or partial loss of the restoration, attributed to factors such as low flexural strength of the cement, inadequate preparation of the cavity, and insufficient retention.

How does GIC compare to other materials in terms of retention and adhesion?

In a systematic review, GIC demonstrated similar retention performance to high-adhesion adhesives with a two-step bonding process. Both materials interact chemically with the dental structure, forming a hybrid layer that contributes to the bonding, though GIC is generally less aesthetic than composites.

What are the main differences between conventional GIC and resin-modified GIC?

Conventional GIC consists of a powder and liquid, with the powder typically made of aluminum silicate glass and the liquid made of polyacrylic acid. Resin-modified GIC, on the other hand, substitutes part of the liquid with water-soluble methacrylate monomers and includes photo-initiators in the powder, allowing for enhanced working time, increased immediate strength, and better moisture resistance.

What are the key benefits and drawbacks of using GIC as a restorative material?

GIC offers several benefits, such as chemical bonding to dental tissue, fluoride release, and ease of use. However, it has some drawbacks, including lower aesthetic quality (especially in color stability and polishing), lower wear resistance, and mechanical properties that are inferior to composite resins.

How does the composition of GIC influence its setting and performance?

The setting of GIC is initiated by an acid-base reaction between the glass powder (which contains aluminosilicate) and the polyacrylic acid liquid. This reaction leads to the formation of a gel, and over time, chemical bonds form, giving the material its final strength. The process can take from three to eight minutes, with complete curing occurring in up to 48 hours.

What is the role of fluoride in GIC, and how does it affect its performance?

Fluoride plays a crucial role in GIC by being released from the material during the setting process. This release of fluoride helps in preventing caries by inhibiting bacterial growth and remineralizing enamel, but it is also responsible for the lack of reactivity in the remaining components after the reaction.

How do resin-modified GICs benefit from the triple-curing mechanism?

Resin-modified GICs benefit from a triple-curing mechanism, which involves an initial acid-base reaction, followed by light activation for polymerization and a chemical polymerization through a redox reaction. This allows for greater flexibility in material insertion and reduces the need for incremental layering, making the material easier to work with.

What should dental professionals consider when choosing GIC for restorations?

When selecting GIC, dental professionals should consider factors such as the restoration's location, the number of surfaces involved, aesthetic concerns, the material's mechanical properties, and its ability to bond to dental tissues. For long-term restorations, the choice of material should also account for the wear resistance and color stability.