In the field of restorative and adhesive dentistry, one of the major challenges clinicians face is ensuring the long-term stability of the dentin-resin interface, particularly in deep cavity preparations where dentin collagen fibrils are exposed and prone to enzymatic degradation.
Over time, the hybrid layer formed between adhesive resins and demineralized dentin can deteriorate due to the activity of endogenous matrix metalloproteinases (MMPs) and cysteine cathepsins, compromising bond integrity and leading to restoration failure.
To counter this, materials that enhance the structural stability of dentin while simultaneously reducing sensitivity and microbial contamination are essential.
One of the most studied and widely used solutions in this context is Gluma®, a desensitizing and collagen-crosslinking agent composed of:
✔ 5% glutaraldehyde, a fixative and protein-crosslinker that denatures proteins and inactivates MMPs.
✔ 35% HEMA (2-hydroxyethyl methacrylate), a hydrophilic resin monomer that infiltrates exposed tubules and creates a sealing resin matrix.
This dual-action formula has been shown to improve adhesive bond longevity, reduce dentin hypersensitivity, and inhibit collagen degradation, making it a valuable adjunct in both direct and indirect restorative procedures.
What is Gluma®?
Gluma® Desensitizer is a clear liquid that combines:
✔ 5% glutaraldehyde – a potent cross-linking and antimicrobial agent.
✔ 35% HEMA (2-hydroxyethyl methacrylate) – a hydrophilic monomer that penetrates dentinal tubules and facilitates resin infiltration.
This formulation works synergistically to reduce dentin hypersensitivity, disinfect prepared cavities, and enhance the durability of adhesive bonds.
Clinical Applications and Benefits
1. Dentin Desensitization
When applied to exposed dentin or cavity preparations, glutaraldehyde coagulates serum proteins inside the tubules, preventing fluid movement that triggers pain. HEMA polymerizes in the tubules, forming a sealing film. This dual action provides instant and long-lasting relief from hypersensitivity.
2. Cavity Disinfection
Residual bacteria after caries excavation pose a risk for recurrent decay and pulpal irritation. Gluma® has been shown to significantly reduce microbial load—especially Streptococcus mutans—without compromising the bond strength of adhesive systems.
3. MMP Inhibition and Collagen Stabilization
The long-term degradation of the dentin-resin interface is linked to the activity of endogenous matrix metalloproteinases (MMPs). Glutaraldehyde cross-links collagen fibrils and inactivates MMPs, thus enhancing the integrity and longevity of hybrid layers in bonded restorations.
4. Compatibility with Adhesive Systems
Gluma® is compatible with both etch-and-rinse and self-etch adhesives. It can be applied after etching or before priming, depending on the adhesive protocol.
5. Use in Indirect Restorations
In crown, bridge, and veneer preparations, applying Gluma® before cementation helps minimize postoperative sensitivity, especially when dentin is freshly cut and close to the pulp.
Conclusion
Gluma® stands as a scientifically validated adjunct in restorative dentistry, helping clinicians improve outcomes by reducing sensitivity, enhancing bond longevity, and providing antibacterial benefits—all within a single application.
Its integration into daily practice represents a best-practice standard for adhesive protocols worldwide.
Scientific Support
- David H. Pashley - Sabatini et al. (2014)
Inhibition of endogenous human dentin MMPs by Gluma
- Carrilho, M. R. O., et al. (2019).
Inactivation of matrix-bound MMPs by cross-linking agents in dentin.
- E. Mancuso et al. Journal of Dentistry (2023).
Effect of Gluma desensitizer on bond strength and MMP activity in adhesive interfaces.
- Samar Hatem Abuzinadah and Abdulrahman Jafar Alhaddad (2021).
A randomized clinical trial of dentin hypersensitivity reduction over one month after a single topical application of comparable materials.
