Hello Robert,

My name is Bob Sloan and I am with a company named Precision Tips. My partner, Charles Buzzetti, has posted on this topic in the past. I would like to try to explain some of the issues regarding polishing of sapphire laser tips.

The sapphire used in the Waterlase tips is single crystal sapphire that is machined to specifications determined by the manufacturer, which allows maximum propagation of light energy through the tip. Single crystal sapphire is extremely hard, Mohs 9, (Diamond 10, Quartz 7) and also very brittle. Both of these properties create issues that must be addressed when polishing the end face. Single crystal sapphire is also self-cladding. This means that if light enters the tip within the angle of incidence, (the angle at which the maximum amount of light will enter and propagate down the light guide) the physical properties of the sapphire “hold” the light within the light guide. Light will not exit through the sides of the tip. This is where the angularity of the end face (especially the proximal end) becomes critical. If the angle of incidence is not maintained through mirror alignment or the angle of the end face, light will be reflected off of the end face, be emitted out the sides of the tip, or reflected back toward the mirror.

Polishing issues encountered include; difficulty in polishing hard material, fretting (chipping) of the end face edges, scratching of the outside surfaces of the light guide (this can destroy the self cladding properties) and maintaining end face flatness and angularity. Without the proper abrasives and tooling, polishing the Biolase tips to meet minimum specifications for angularity, flatness, and removal of defects is extremely difficult. I would be apprehensive about putting a very expensive piece of equipment in jeopardy by using a tip that may not meet the specifications needed for maximum light transmission. If you cannot verify that the physical specifications of the tip are being maintained, you cannot be sure that the tip will operate effectively. It took us a several months to develop the procedures required to produce a product that performs to at least the specifications required by the manufacturer. Also, our inspection equipment is designed to give us the means to observe all relevant characteristics that assures us that a tip meets the physical properties required for safe, effective operation. Because of our adherence to strict procedures, in the two years since we began doing this, we have not had any reported cases of a tip failure due to our work. To conclude, in my opinion, merely polishing a damaged tip would not be in your best interest.

My suggestion to you would be to send to us any damaged sapphire tips that you have. We will evaluate them to determine if they can be repaired. I would be very happy to refurbish a tip for you and return it to you at no charge, for your evaluation.

Even if you do not want to use our service, any sapphire tips that you have, that are refurbishable, have value. We will purchase them from you. Demand for refurbished tips is high and we have a hard time building an inventory. The great majority of dentists want their tips refurbished and returned to them.

I hope I have not been too long winded. Please feel free to contact me privately at bs@dentallasertips.com if you have questions that you would prefer to not ask publicly. We are quite willing to discuss what we do with anyone who has concerns or questions.

Bob Sloan
Precision Tips