Dental coding can be complicated. Codes change based on surface area, number of teeth involved, tooth placement, and sometimes the position of the moon in the sky. Okay, maybe not the last one, but it feels true!
These different dental coding characteristics are called “modifiers.”
Coding for dental insurance usually falls to your clinical staff members as they treatment plan and complete procedures in the patient’s chart. However, it is important to be able to recognize the codes and modifiers used so that you can be another layer of review before submission. Here are three procedures where the coding changes depending on the modifiers:
- Scaling and Root Planing
- Inlays and Onlays
- Root canals
Scaling and root planing is also known as a “deep cleaning” or “SRP.”
It is the process of removing calculus and plaque from the entire surface of the tooth, both above and below the gumline. The main focus in SRP is to remove infection, reduce inflammation, and allow the gums to reattach to the teeth to slow the progression of periodontitis.
SRP is coded per quadrant as either D4341 or D4342. When four or more teeth in a quadrant have deep gum pockets (4 or more mm deep), it is coded as a D4341. When one to three teeth in a quadrant have deep pockets, it is coded as a D4342. There is no rule that every quadrant completed must be billed out the same way, nor are you required to do every quadrant in the mouth if it is not medically necessary.
Inlays and onlays are often used when restoring teeth that require more than a filling but may not necessarily need a crown.
A tooth with a hole in it, for example, would benefit from an inlay or an onlay. To quote the Front Office Roles E-book:
“An inlay is a solid piece of material that is fabricated in the lab and cemented into place in a tooth. An impression is taken of the exact hole that needs filled and the inlay fits perfectly inside it…Onlays hold the same role and definition as inlays, but for the cusps of the tooth. If the points (cusps) of the tooth have been damaged and must be replaced, it is an onlay.”
The image above portrays an onlay, as it involves the cusp of the tooth.
Inlays and onlays are billed based on two modifiers: material and number of surfaces. These can be either metal-based or porcelain/ceramic. Inlays are billed as either one surface, two surfaces, or three or more surfaces. Onlays are billed as either two surfaces, three surfaces, or four or more surfaces. Keep in mind this is the number of tooth faces involved, not how many cusps.
In the above image, for example, the onlay being placed is for two surfaces (each side of the cusp) and made of porcelain. Therefore, it would be coded as a D2642. Please see the image below for the full list of inlay/onlay codes.
These codes are included in the Flawless Front Office: Front Office Roles E-Book, available in our Shop!
Our third dental coding procedure is the root canal – the procedure to remove diseased pulp and clean the roots of a tooth.
This is also known as endodontic therapy. Root canal codes are modified by the tooth’s placement in the mouth. A D3310 would be used to bill out endodontic therapy on an anterior tooth. A D3320 would be used for a pre-molar, while a D3330 would be used to code a molar tooth.
These three are just examples of procedures with modifiers. One of the biggest areas of coding error is actually fillings. Fillings are modified by number of surfaces and placement in the mouth. They are then further modified by the specific tooth surfaces that are being treated.
Check out our Coding For Fillings Art printable designed specifically to answer the question, “What code am I supposed to use again?”
Learning dental coding is easier with some basic dental anatomy knowledge. We have also created Faces of the Tooth Art focusing specifically on explaining the difference between distal, mesial, occlusal, etc.
Looking for more in-depth education on dental anatomy and dental coding? Our full Flawless Front Office: Front Office Roles E-Book addresses both of those topics and more, including insurance terminology, dental reception, and dental treatment planning. If you know your role and are just looking for a little extra, we also offer the Dental Coding Bundle at a discounted rate from the e-book.
During the month of July 2025, we have a sale going on for our E-book! Use code ffolaunch to discount the full cost of the book by $20.
Join us next time for: Five of the Biggest Insurance Mistakes That Grow Your Aging Report!