The move to milled Zirconia for full-contour crowns and bridges continues to grow and if you are currently outsourcing your zirconia copings and crowns to a milling center, there will come a time when your monthly volume will have you asking if it is time to purchase your own dental milling equipment. AMS Dental Technologies, one of the ACDLA sponsors, indicates that the choice to invest in dental lab equipment varies quite a bit among their customers. Some very large customers have indicated they prefer to continue outsourcing this part of their business so they can concentrate on the hands-on finishing work and more personalized services to their dentists without having to also manage the milling activity. Other labs seek to purchase their own mill as soon as the “numbers make sense financially”. ACDLA recently spoke with Kim Karpowitz of Digital Dental Lab, a manufacturer of dental milling equipment, about what labs should be sure to consider when selecting a dental milling machine.
There are five major considerations in looking to purchase a milling machine for your dental lab.
3. Return on investment
Capability: One of the most important questions to know are the capabilities of the machine. This will be very important in comparing various models and manufacturers.
- What materials can I machine?
- How many pucks does it hold?
- Can I run the machine unattended?
- What can I expect from “Axis” beyond X, Y, and Z?
- How many tools can I use?
- What can I make beyond copings and crowns?
Longevity: The life of your milling machine will be determined by two major factors. The first, and most important is the construction of the machine. Machines that are made to last share some common attributes:
- They have large precision Balls Screws (12mm or larger).
- Ball Screws should be supported on both ends.
- Sliding services should employ box or square construction rather than round (12mm or larger).
- Controllers should run in “closed loop” for the greatest amount of accuracy and speed.
- Heavy casting or billet construction will provide the longest life.
- A precision spindle with programmable speeds to 60,000 RPM insures the finest finishes.
The length of the factory warranty and the cost of maintenance should give you a good idea of how confident the manufacturer is of his product.
The second factor in determining longevity will be determined by the way you maintain your machine.
- Is the vacuum working well.
- Are sliding services and Ball Screw well greased.
- Are the protective elements like bellows and way covers well maintained. If you have an excessive build up of chips or zirconia dust in the machine you can be sure you are shorting the lifespan of your equipment.
Price: When considering price, it is important to be sure you understand the total price of the purchase. Include fixtures, vacuum, lubricators, pumps, and other ancillary equipment in addition to the quoted price of the mill. Also, be sure you get a clear understanding of the cost of operations for years two through five.
- Is there an annual maintenance cost?
- What will be the cost of tools (quantify to a cost per unit)
Return: Calculating the breakeven cost and the return on investment are important numbers that help to really frame your understanding of price. You will want to calculate the costs of manufacturing.
- How many restorations can I machine in a twenty-four period?
- What are the cost of manufacturing ? (Zirconia, Tools, Wax, PMMA, Titanium, abutment blanks, labor)
In order to calculate your monthly return on investment:
1) Take the total cost of the machine including the annual maintenance cost for five years. Divide that number by sixty months and times it by your cost of money (7% is a reasonable lease cost to estimate). This will give you you the monthly cost of owning the machine.
2) Now take a conservative production number for a month (how many units you will manufacture and sell), multiply this number by the selling price to get your total revenue and multiply it by the cost of manufacturing to get your total manufacturing cost. Then subtract the cost from our revenue.
You have now come up with a projected gross profit resulting from the machines production in one month.
3) Subtract the monthly cost of the machine from the monthly gross profit. You have a monthly ‘return on investment.
4) This is an important number for you to understand, but it is not the same as knowing your profitability for milling your own zirconia. Be sure you also add in the cost of the sintering process, the labor for the milling machine, and the electricity cost associated with running this equipment. While the cost related to the milling machine itself might be profitable, once you add these other costs, you may find your break-even is higher than originally considered.
Serviceability: Even the best machine will breakdown periodically. You will want to be sure you understand the guaranteed “response time” is of the manufacturer.
- Are spare parts readily available?
- How long does it take to secure replacement parts?
- Ask for specific costs related to the replacement of major components like motors, drives, and spindles.
- How many customer service technicians are available to help you?
- In what time zone does service come from?
- Is loaner equipment available if the machine can’t be fixed the same day as the call?
- If I require a service man to come to my lab, what is the cost (both in and out of the warranty period)?
Finally be sure to ask if the manufacturer of the machine will address all of the issues that may be associated with your equipment (i.e., the vacuum, CAM system, tooling issues, the furnace/oven, and the scanner).
Single Source Responsibility is the ultimate solution for Serviceability.
If you have questions regarding selecting a Dental Milling Machine, feel free to contact us at ACDLA. We are here to assist you. You may also contact Kim Karpowitz at Digital Dental Lab. Be sure to let them know you are an ACDLA member and a member of the AmericaSmiles Network (if applicable). Digital Dental labs brings over 30 years of CAD/CAM experience to the dental industry. Their goal is to bring each laboratory into the digital age with a focus on maximizing their productivity and profitability. They strive to match each customer with the scanner, CAD and milling machine that best fits their needs and budget. Digital Dental Lab can be reached at: 1 (949) 582-1750 of via email at email@example.com