How well zirconia blocks match the adhesive properties of enamel?

The matching of bonding properties between zirconia blocks and enamel is a complex and critical issue, which is directly related to the success and durability of oral restorations. The following is a detailed analysis of the adhesive properties of zirconia blocks and enamel:

First, the bonding performance of zirconia blocks and enamel

As a high-performance ceramic material, zirconia block has a wide range of applications in oral restoration. However, due to its chemical inertness and surface properties, the bonding performance of zirconia blocks to enamel is relatively poor. The bond strength of zirconia without pretreatment is almost zero, and even after treatment with silane or hydrofluoric acid, the bond strength remains low. This is mainly because the surface of zirconium oxide contains little silicate and little glass phase, making it difficult to form an effective chemical bond with enamel.

Second, the method of improving bonding performance

In order to improve the bonding properties of zirconia blocks to enamel, researchers and clinicians have used a variety of methods, including but not limited to:

Surface treatment:

Sandblasting: the roughness of the zirconia surface is improved by sputtering aluminum oxide particles to increase the mechanical retention force. Sandblasting is a routine technique that is widely used in clinical practice, but care needs to be taken to control the sandblasting parameters (e.g., air pressure, angle, distance, and time) in order to avoid damage to the zirconia.

Coating treatment: For example, sol-gel coating treatment can form a layer of uniform nanoporous structure on the surface of zirconia, improve surface roughness and wettability, and thus enhance the bonding strength with tooth enamel.

Use specialized bonding agents:

Phosphate monomer MDP: MDP is the most widely used and most effective in clinical practice, and it can form a stable chemical bond with zirconium oxide through ionic bonding or hydrogen bonding, which effectively improves the immediate bonding strength.

Self-etching resin bonding agent: Compared with full acid etching bonding agent, self-etching resin bonding agent is easier to operate and does not require a separate acid etching step, so it is more widely used in the clinic.

Other methods:

UV irradiation: it can enhance the hydrophilic property and cell adhesion ability of the surface of zirconia material, thus indirectly improving the bonding performance.

Laser treatment: Using the high-energy properties of laser to treat the surface of zirconia can increase the surface roughness and wettability, and improve the bonding strength.

Third, the evaluation of bonding performance matching

The evaluation of bonding performance match is usually carried out through laboratory tests and clinical follow-up. Laboratory tests include shear strength tests, microtensile strength tests, etc. to quantify the bonding performance. Clinical follow-ups reflect the actual effect of bonding performance by evaluating the retention rate of restorations, success rate, patient satisfaction, and other indicators.

Fourth, conclusion

Overall, the bonding performance match between zirconia blocks and enamel can be significantly improved by various methods. However, due to the complexity of the oral environment and the existence of individual differences, the actual effect of bonding performance may vary depending on individual circumstances. Therefore, in clinical application, the surgeon needs to select the appropriate bonding solution according to the patient's specific situation and conduct adequate preoperative evaluation and postoperative follow-up to ensure the success rate and durability of the restoration.

Conclusion: Although the bonding performance match between zirconia blocks and enamel is relatively poor, it can be significantly improved by appropriate surface treatment and the use of specialized bonding agents. In clinical application, the surgeon needs to choose the appropriate bonding solution according to the patient's specific situation and conduct adequate preoperative evaluation and postoperative follow-up.

Translated with DeepL.com (free version)