Frequently Asked Questions – GIC 101

1. Why does my GIC restoration debond in a short period of time?

Glass ionomer cement (GIC) restorations may debond prematurely due to several factors related to their mechanical properties and bonding strength. Here are the key reasons and insights from the research:

Factors Contributing to Debonding

• Mechanical Properties: GICs have relatively weak mechanical properties compared to other materials like resin composites, which can lead to debonding under occlusal stress (V.S et al., 2023). The compressive strength of GIC is generally lower, making it less capable of withstanding the forces exerted during chewing (V.S et al., 2023).
• Bond Strength Issues: The bond strength of GIC to dentin or enamel can be compromised by surface contamination, such as residual silicone or saliva. Studies show that silicone residue significantly reduces the shear bond strength of GIC to dentin (Anusha et al., 2019). Similarly, saliva contamination can reduce the tensile bond strength of GIC to enamel, although this can be mitigated by specific surface treatments (Chen et al., 2002).
• Surface Preparation: Proper surface preparation is crucial for optimal bonding. Inadequate cleaning or preparation of the tooth surface can lead to poor adhesion and subsequent debonding (Anusha et al., 2019; Chen et al., 2002).
• Fatigue and Load: GIC restorations are more prone to failure under fatigue loading conditions. Teeth restored with GIC cores have shown significantly lower fracture strength compared to those restored with resin composites, especially under cyclic loading (Taha et al., 2014).

Mitigation Strategies

• Surface Treatments: Using wet pumice, phosphoric acid, or polyacrylic acid can improve the bond strength by effectively removing contaminants like silicone residue (Anusha et al., 2019). For saliva contamination, air drying or applying maleic acid or Scotchbond primer can restore bond strength (Chen et al., 2002).
• Material Selection: Considering the use of resin-modified GICs or composite resins for areas subjected to high stress may reduce the risk of debonding over time (Mickenautsch et al., 2011).

Conclusion

GIC restorations may debond prematurely due to their weaker mechanical properties, contamination during bonding, and inadequate surface preparation. Addressing these issues through proper surface treatments and considering alternative materials for high-stress areas can help improve the longevity of GIC restorations.

2. Why is my GIC restoration not as smooth as required?

If your Glass Ionomer Cement (GIC) restoration is not as smooth as required, several factors could be contributing to this issue. Here are some potential reasons and considerations:

Factors Affecting Smoothness

• Polishing Techniques: The ideal polishing tools for GIC in pediatric dentistry are still under development, which may affect the smoothness of the restoration. The constant evolution of dental materials and polishing products necessitates ongoing research to find optimal solutions (Koupis et al., 2007).
• Material Properties: GICs have inherent properties that might affect their surface texture. For instance, the high-viscosity consistency of GIC can lead to incorrect adaptation in the cavity, potentially resulting in a rougher surface (Hesse et al., 2016).
• Restoration Techniques: The technique used for inserting GIC can impact the final smoothness. The bilayer technique, for example, has been shown to improve the survival and potentially the surface quality of restorations compared to conventional methods (Hesse et al., 2016).
• Surface Protection: The use of surface protection materials, such as nano-filled coatings, can enhance the longevity and surface quality of GIC restorations. Coated restorations have shown better survival rates and potentially smoother surfaces than uncoated ones (Hesse et al., 2016).

Material Comparisons

• GIC vs. Resin Composites: While GICs are effective for certain applications, they may not always match the smoothness and aesthetic qualities of resin composites. Resin composites generally show better performance in terms of marginal adaptation and surface texture (Oz et al., 2020; Bezerra et al., 2020).

Conclusion

The smoothness of your GIC restoration can be influenced by the choice of polishing techniques, the inherent properties of the GIC material, and the specific restoration techniques used. Exploring advanced techniques like the bilayer method and using protective coatings can potentially improve the smoothness and longevity of GIC restorations. If smoothness remains a concern, consulting with your dentist about alternative materials or techniques may be beneficial.

3. Why did the patient develop sensitivity after GIC restoration?

The development of sensitivity after glass ionomer cement (GIC) restoration can be attributed to several factors related to the properties and application of the cement.

Factors Contributing to Sensitivity

• Type of Cement: GIC is known to cause higher postoperative sensitivity compared to resin cements. This sensitivity is often more pronounced several days after the procedure (Farias et al., 2014; Shetty et al., 2012).
• Removal of Smear Layer: The removal of the smear layer by acid-etching can increase dentin permeability, leading to sensitivity. This is a common practice in preparation for cementation and can contribute to postoperative discomfort (Farias et al., 2014).
• Tooth Preparation and Restoration Technique: Aggressive tooth preparation and inadequate provisional restorations can also lead to increased sensitivity. Proper technique and care in preparation can mitigate this risk (Farias et al., 2014).
• Dentin Permeability: GIC may not effectively occlude dentinal tubules, which can lead to increased sensitivity. The use of dentin desensitizers can help block these tubules and reduce sensitivity (Farias et al., 2014).

Comparative Sensitivity

• GIC vs. Resin Cement: Studies have shown that GIC tends to result in higher postoperative sensitivity compared to resin cements, particularly noticeable a week after cementation (Shetty et al., 2012). This suggests that resin cements might be preferable if minimizing sensitivity is a priority.

Conclusion

Sensitivity after GIC restoration is primarily due to the inherent properties of the cement, the removal of the smear layer, and the techniques used during tooth preparation. While GIC is a common choice for restorations, its tendency to cause sensitivity can be mitigated by using dentin desensitizers and considering alternative cements like resin-based options for patients sensitive to postoperative discomfort.

4. Why is my GIC restoration not adapting properly to the cavity walls?

If your Glass Ionomer Cement (GIC) restoration is not adapting properly to the cavity walls, several factors could be contributing to this issue. Here are some potential reasons and solutions based on current research:

Factors Affecting GIC Adaptation

• Consistency and Application Technique: The high-viscosity consistency of GIC can lead to poor adaptation. Using a flowable GIC layer as a liner can improve adaptation in approximal restorations, although it may reduce flexural strength (Hesse et al., 2016; Bonifácio et al., 2013; Bonifácio et al., 2013). The bilayer technique, which involves using a flowable GIC layer, has shown better adaptation and survival rates in some studies (Hesse et al., 2016; Bonifácio et al., 2013).
• Surface Roughness: The texture of the cavity wall can influence the adaptation of restorative materials. Variations in the surface condition due to different types of instrumentation can affect the sealing properties of the GIC (Menegale et al., 1960).
• Insertion Technique: Proper insertion techniques are crucial. The bilayer technique and the use of nano-filled coatings have been shown to improve the longevity and adaptation of GIC restorations (Hesse et al., 2016).
• Material Properties: The mechanical properties of the GIC, such as its flexural strength, can affect its performance. A two-layer GIC with a flowable layer may have lower flexural strength, which could impact its durability under load (Bonifácio et al., 2013).

Recommendations

• Consider Using a Bilayer Technique: This involves applying a flowable GIC layer first, followed by a conventional GIC layer. This method has been shown to improve adaptation and reduce stress concentration (Hesse et al., 2016; Bonifácio et al., 2013).
• Surface Preparation: Ensure that the cavity walls are properly prepared to enhance the bonding and adaptation of the GIC. This might involve adjusting the surface roughness to optimize the material’s sealing properties (Menegale et al., 1960).
• Evaluate Application Techniques: Experiment with different application techniques, such as using a flowable GIC liner or a nano-filled coating, to see which provides the best adaptation in your specific case (Hesse et al., 2016; Bonifácio et al., 2013).

Conclusion

Improper adaptation of GIC restorations can be due to factors like material consistency, surface roughness, and application techniques. Using a bilayer technique or adjusting the surface preparation may improve adaptation. Consider these strategies to enhance the performance and longevity of your GIC restorations.

References

1. Anusha, R., Sajjan, M., Raju, A., Bheemalingeswararao, D., & Chary, N. (2019). Evaluation of the effect of silicone residue after different surface treatments on shear bond strength of glass ionomer cement to the dentin surface. The Journal of the Indian Prosthodontic Society, 19, 126 – 133. https://doi.org/10.4103/jips.jips_276_18
2. Taha, N., Palamara, J., & Messer, H. (2014). Fracture strength and fracture patterns of root-filled teeth restored with direct resin composite restorations under static and fatigue loading.. Operative dentistry, 39 2, 181-8. https://doi.org/10.2341/13-006-L
3. Mickenautsch, S., Yengopal, V., & Banerjee, A. (2011). Retention of orthodontic brackets bonded with resin-modified GIC versus composite resin adhesives—a quantitative systematic review of clinical trials. Clinical Oral Investigations, 16, 1 – 14. https://doi.org/10.1007/s00784-011-0626-8
4. Chen, C., Huang, G., Guo, M., & Lin, C. (2002). An in vitro study on restoring bond strength of a GIC to saliva contaminated enamel under unrinse condition.. Journal of dentistry, 30 5-6, 189-94. https://doi.org/10.1016/S0300-5712(02)00019-2
5. Koupis, N., Marks, L., Verbeeck, R., & Martens, L. (2007). Review: Finishing and polishing procedures of (resin-modified) glass ionomers and compomers in paediatric dentistry. European Archives of Paediatric Dentistry, 8, 22-28. https://doi.org/10.1007/BF03262566
6. Oz, F., Meral, E., Ergin, E., & Gurgan, S. (2020). One-year evaluation of a new restorative glass ionomer cement for the restoration of non-carious cervical lesions in patients with systemic diseases: a randomized, clinical trial. Journal of Applied Oral Science, 28. https://doi.org/10.1590/1678-7757-2020-0311
7. Bezerra, I., Brito, A., De Sousa, S., Santiago, B., Cavalcanti, Y., & De Almeida, L. (2020). Glass ionomer cements compared with composite resin in restoration of noncarious cervical lesions: A systematic review and meta-analysis. Heliyon, 6. https://doi.org/10.1016/j.heliyon.2020.e03969
8. Hesse, D., Bonifácio, C., Guglielmi, C., Bönecker, M., Van Amerongen, W., & Raggio, D. (2016). Bilayer technique and nano-filled coating increase success of approximal ART restorations: a randomized clinical trial.. International journal of paediatric dentistry, 26 3, 231-9. https://doi.org/10.1111/ipd.12194
9. Farias, D., Walter, R., & Swift, E. (2014). Critic appraisal. Postoperative sensitivity with indirect restorations.. Journal of esthetic and restorative dentistry : official publication of the American Academy of Esthetic Dentistry … [et al.], 26 3, 208-13. https://doi.org/10.1111/jerd.12103
10. Shetty, R., Bhat, S., Mehta, D., Srivatsa, G., & Shetty, Y. (2012). Comparative analysis of postcementation hypersensitivity with glass ionomer cement and a resin cement: an in vivo study.. The journal of contemporary dental practice, 13 3, 327-31. https://doi.org/10.5005/JP-JOURNALS-10024-1146
11. V.S, R., J, L., & S, D. (2023). Assessment of Occlusal Load Strength of Glass Ionomer Cement and Composite in Class V Cavities: An In-Vitro Study. Cureus, 15. https://doi.org/10.7759/cureus.49529
12. Hesse, D., Bonifácio, C., Guglielmi, C., Bönecker, M., Van Amerongen, W., & Raggio, D. (2016). Bilayer technique and nano-filled coating increase success of approximal ART restorations: a randomized clinical trial.. International journal of paediatric dentistry, 26 3, 231-9. https://doi.org/10.1111/ipd.12194
13. Menegale, C., Swartz, M., & Phillips, R. (1960). Adaptation of Restorative Materials as Influenced by Roughness of Cavity Walls. Journal of Dental Research, 39, 825 – 835. https://doi.org/10.1177/00220345600390040901
14. Bonifácio, C., Hesse, D., Rocha, R., Bönecker, M., Raggio, D., & Amerongen, W. (2013). Survival rate of approximal-ART restorations using a two-layer technique for glass ionomer insertion. Clinical Oral Investigations, 17, 1745-1750. https://doi.org/10.1007/s00784-012-0859-1
15. Bonifácio, C., De Jager, N., & Kleverlaan, C. (2013). Mechanical behavior of a bi-layer glass ionomer.. Dental materials : official publication of the Academy of Dental Materials, 29 10, 1020-5. https://doi.org/10.1016/j.dental.2013.07.008