The advantages of sapphire as a waterproof lens for oral endoscopes are mainly reflected in the following aspects:

1、 Physical performance advantages

Ultra high hardness and wear resistance

The Mohs hardness reaches level 9, which can resist the friction of surgical instruments and the physical wear of complex oral environments. It can maintain the smoothness of the lens surface (Ra ≤ 0.5nm) for a long time, avoiding scratches and damage to the waterproof layer.

Reduce the risk of sealing failure caused by surface wear and extend the service life of lenses by 56.

Excellent optical performance

Transmittance>99.5%, wide spectrum (0.15-5.5 μ m) with high transmittance characteristics, providing clear imaging even in humid environments, ensuring diagnostic accuracy.

2、 Chemical and Biological Stability

Corrosion resistance and chemical resistance

The inert material properties enable it to resist the erosion of chemical substances such as saliva and drug residues in the oral cavity, avoiding damage to the waterproof structure caused by corrosion.

Surface coating technology (such as single-sided coating) can further isolate liquid infiltration and reduce the interface reaction between the lens and moisture contact.

Biocompatibility

Non toxic and non immunogenic, suitable for long-term contact with human tissues, reducing sealing problems or infection risks caused by material reactions.

3、 Environmental tolerance

High temperature and high pressure resistance

Can withstand high temperature steam sterilization (over a thousand cycles), ensuring the structural integrity of the lens after repeated disinfection and maintaining waterproof performance.

Low coefficient of thermal expansion (5.3 × 10 ??/K), not easily deformed at high temperatures, avoiding seal failure.

?Surface treatment technology

By using processes such as plasma cleaning and laser annealing, the adhesion of the metallization layer is enhanced, and the overall sealing and waterproof properties of the lens components are improved.

4、 Comprehensive cost-effectiveness

Although the procurement cost is high, its lifetime maintenance free feature (such as reducing replacement frequency and avoiding equipment failures caused by water seepage) can reduce long-term usage costs by 15.

In summary, sapphire has become an ideal choice for waterproof lenses in oral endoscopes due to its hardness, chemical stability, environmental resistance, and advanced surface treatment technology.