Dental Microscope How-to Guide: Focusing Your Scope

In the mid-1990’s, the incorporation of dental microscopes into treatment began to increase as clinicians took notice of  higher magnification levels and greater illumination that are not possible with dental loupes. Around this time, the AAE (American Association of Endodontists) began strongly advocating for the use of a microscope in dental practices as well as during doctoral study. Our founders – with a long and distinguished history of serving the Otolaryngology market – built on our manufacturing strengths in medical equipment and became the first company to focus on the newly emerging dental microscopy market.

With our over 25 years in business, we have extensive experience working with doctors to maximize their value in a dental microscope. We’ve taken considerable notes from conversations with our customers to apply their feedback, both with our product and accessory designs, as well as the training, manuals and articles we produce to help new customers get up and running on their scope as efficiently as possible.

To help, we’re launching one of the most requested reference materials from doctors we work with – our “Dental Microscope How-to Guide.”. Each article in this series will include easy-to-follow steps to help reduce the number of training hours on specific areas most commonly referenced by doctors we work with. 

Now, because we’ve worked with thousands of doctors over our years in business, we’ve received  a range of responses when it comes to the learning curve on a dental microscope. For example, Dr. Evan Miller told us: “Worst thing I ever did was listen to the experts about a “learning curve” to use the scope. There simply is none!” 

Whether or not you’ve trained on a scope, we tell our customers to typically expect a  4-6 month period of using your scope before you’ll achieve an optimum level of familiarity with how and when you’ll use it and the speed and efficiency at which you’ll operate.

Today, we’re offering our expertise on the topic of focusing, or parfocal adjustment, of a dental microscope – one of the most important skills to master in order to feel comfortable adjusting between magnification powers on your scope.

All About Focus In Dentistry

Our eyes help us process the world around us, helping us see objects at various distances. During many dental procedures, the ability to see and focus on fine details impacts the precision of your diagnoses and treatment. 

Magnification helps overcome our eye’s natural limitations by effectively bringing objects closer to the eye. When you change magnification level, you are also changing the focal length, which changes the distance at which an object remains in focus. Dental microscopes solve for this by using parfocal lenses to help stay in focus when magnification/focal length is changed.

The ability to adjust  focus when changing magnification levels is unique to dental microscopes and is a significant improvement over its predecessor, dental loupes. Since loupes are worn on your head, your focus is fixed at a set distance. For the duration of  treatment, any movement can cause your view to become blurred to a greater or lesser extent. You must always keep your loupes at the correct working distance to enjoy a fully focused image, which can be a difficult task.. 

Dental microscopes, on the other hand, are mounted to stabilize your positioning and ability to focus on finer details for longer durations. Plus, most dental microscope brands offer coarse and fine focus settings to help you optimize your focus without repositioning your body.

Here’s a general overview of how these settings function:

• Adjust coarse focus by raising or lowering the microscope assembly with the spring arm. 
• Adjust fine focus by moving the fine focus objective lens.
• Parfocal adjustment allows the user to adjust the eyepieces to correct for nearsightedness or farsightedness.

NOTE: It is essential to perform the parfocal adjustment prior to using any still or video camera applications. If the parfocal adjustment is not performed, the microscope can still be focused on a selected magnification, but images from camera might not be in focus.

One important consideration to know as you get started is that each operator of the microscope will require his or her own parfocal settings. This should be set before any procedures are performed. Because your eye correction will change with time, we recommend this procedure be performed by each operator a minimum of one time per year.

As doctors master the ability to focus their microscope, they are able to more efficiently toggle between magnification levels – improving efficiencies with diagnosis and treatment. To help those just getting started with magnification, we’re sharing a concise set of step-by-step instructions to make parfocal adjustments on a microscope.

Step-by-Step Focusing Instructions

1. Position the microscope above a flat stationary surface, with the bottom of the objective lens parallel to the surface.
2. Using a pen or pencil, mark an “X” on a piece of white paper for a focusing target and place it in the center of the illumination field of the microscope.
3. Set the diopter adjustment rings on both eyepieces to “0”.
   • Each binocular eyepiece is equipped with a diopter adjustment ring which is marked in plus(+) or minus(-) one diopter increments. To adjust the diopter setting, firmly grasp the diopter adjustment ring and adjust the settings until the image is clear and sharp.
   • The diopter adjustment corrects for the user’s vision prescription, providing relaxed 20/20 vision with or without glasses or contact lenses. The diopter adjustment has a correction range of +5 diopters to -5 diopters. Users with natural correction outside this range must wear additional corrective lenses to achieve relaxed 20/20 vision.
4. Without looking through the binoculars, adjust the fine focus objective lens to its approximate midpoint.
5. Set the magnification to the highest setting. Raise or lower the microscope vertically until the “X” is in optimum focus.
6. Adjust the fine focus objective lens until a sharp focus is acquired.
7. Set the magnification to the lowest setting. Focus both eyepieces, one at a time, by turning the diopter adjustment ring until the image is clear and sharp. Use direct vision whenever possible to free hands for instruments.

IMPORTANT NOTE: It is particularly important to perform the parfocal procedure when an image through the microscope is clear but the same image through a still or video camera is not focused, or vice-versa.

PRO TIP: Your binoculars are now par-focalled to your vision. When a patient sits in the exam chair, focus at highest magnification at the area you will be working. When the image is focused, you can now use any magnification and all images should be in focus.

Using a Multifocal Lens Attachment

A multifocal or variable focal objective lens uses a split path design to create a simple method for focal adjustment. In the case of a Global microscope, our multifocal lens accessory attaches to your scope, and uses a small dial to provide you with up to 6” total focal adjustment. 

This feature helps you quickly adjust focus as you change working distance or need to accommodate for patient movement. Using this tool, your focusing is more efficient, requiring less repositioning so you can maintain your working posture.

For more information on the multifocal lens accessory, and how to decide if this is right for you, continue reading: The Advantages of a Multifocal Lens.

More Questions? Reach Out!

If you’re looking to get started with magnification, or considering adding a microscope to your practice, we are here to help! In our over 25 years in business, we’ve been helping dental practices see the benefits of magnification with a dental microscope.

We’re proud to be based in the US, with manufacturing and assembly facilities in St. Louis, MO. This helps us give our customers the best service, domestically and internationally. And, as part of our commitment to our customers, we offer a limited lifetime warranty on our scopes (US & Canada customers only).

Please feel free to reach out at 800-861-3585 or by clicking the button below.

Or, if you have a suggestion for our next “How-to” guide, reach out to let us know what would be helpful for you!