Amalgam charting is the process of recording existing or planned amalgam (silver) fillings on a dental chart, using specific symbols, colors, and surface abbreviations to document exactly which teeth and surfaces are involved. Whether you’re a dental assisting student or new to a clinical office, the basics are straightforward once you understand the color conventions, surface codes, and visual cues that distinguish amalgam from other restoration types.
Color Conventions on a Dental Chart
Most dental offices use a two-color system. Black or blue marks on the chart represent dental work that has already been completed, while red marks indicate treatment that still needs to be done. So if a patient walks in with an existing amalgam filling on a lower molar, you would chart it in black or blue. If the dentist diagnoses a new cavity on a different tooth and plans to place an amalgam restoration, that planned filling gets charted in red.
Some offices add a layer to this system: they use black or blue specifically for silver amalgam restorations and reserve red (or another color) for tooth-colored composite restorations, even when both are already completed. There is no single universal standard here. The most important thing is to follow the convention used in the office where you work and apply it consistently so every team member reads the chart the same way.
On the chart itself, you fill in (solid color) the outline of the affected tooth surfaces to represent an amalgam restoration. A composite filling, by contrast, is typically drawn as an outline only, without filling it in solid. This visual shorthand lets anyone glancing at the chart instantly tell the difference between a silver filling and a tooth-colored one.
Tooth Surface Abbreviations
Every filling involves one or more surfaces of a tooth, and each surface has a standard single-letter abbreviation:
- M = Mesial (the side facing toward the front of the mouth)
- O = Occlusal (the chewing surface on back teeth)
- D = Distal (the side facing toward the back of the mouth)
- B = Buccal (the cheek-facing surface)
- L = Lingual (the tongue-facing surface)
- F = Facial (used interchangeably with buccal in some offices)
These abbreviations combine to describe multi-surface restorations. An “MO” amalgam means the filling covers both the mesial and occlusal surfaces. “MOD” covers mesial, occlusal, and distal, which is a large filling spanning most of the top of a back tooth. “MODB” adds the cheek side as well. When you chart an amalgam, you shade in exactly those surfaces on the tooth diagram and note the abbreviation in the written record.
How to Identify Amalgam in the Mouth
Before you can chart an existing restoration, you need to recognize what you’re looking at. Amalgam fillings are silver-colored and metallic, which is why patients often call them “silver fillings.” Over time they can tarnish to a darker gray or even blackish shade, but the metallic appearance remains distinctive. Composite resin fillings, by contrast, are color-matched to the surrounding tooth and can be difficult to spot visually.
On dental X-rays, amalgam shows up as a bright, highly opaque (white) area because the metal blocks nearly all radiation. Composite appears lighter than tooth structure but far less bright than amalgam. Gold restorations also appear very radiopaque, but they’re much less common. Recognizing these differences on both visual exam and radiographs helps you chart accurately.
Restoration Classification
Dental offices often reference the G.V. Black classification system when documenting restorations. Originally introduced in 1896, this system groups cavities and fillings into classes based on their location on the tooth. While considered outdated by some researchers, it remains widely used in everyday charting. The classes most relevant to amalgam are:
- Class I: Cavities in the pits and grooves of the chewing surfaces, typically on molars and premolars. This is the most common location for amalgam.
- Class II: Cavities on the proximal (side) surfaces of back teeth. MO, DO, and MOD amalgams fall here.
- Class V: Cavities along the gumline on the facial or lingual surface of any tooth. Amalgam is occasionally used here, though composite is more common today.
Classes III and IV involve the front teeth, where tooth-colored materials are almost always preferred for appearance. You will rarely chart an amalgam in these locations on a modern patient, though you may encounter them in older dental work.
Charting Step by Step
When you examine a patient and find an existing amalgam restoration, the charting process follows a predictable sequence. First, identify the tooth by number. In the Universal Numbering System used in the United States, permanent teeth are numbered 1 through 32 starting from the upper right third molar. Next, identify which surfaces the restoration covers by examining the tooth from multiple angles and confirming with X-rays if needed.
On the paper or digital chart, locate that tooth’s diagram and shade in the corresponding surfaces with the appropriate color (typically black or blue for an existing amalgam). In the written notes or software entry, record the tooth number, the surface abbreviation, and the material type. For example: “#19 MOD amalgam, existing” tells any provider that tooth 19 (a lower left first molar) has a three-surface silver filling already in place.
For a planned amalgam restoration, you would use the same process but mark it in red (or whatever color your office designates for treatment-planned work). Once the filling is placed, the entry gets updated to the “completed” color.
Digital Charting Software
Many offices now use practice management software such as Dentrix or Eaglesoft, which replaces paper charts with interactive tooth diagrams on screen. These programs let you click on a tooth, select the surfaces involved, and choose the restoration type from a dropdown menu. The software automatically color-codes and records the entry, reducing errors and making the chart searchable.
Some platforms now integrate artificial intelligence tools that can help detect cavities on X-rays and support hands-free entry of clinical notes. The charting logic, however, stays the same: you still need to correctly identify the tooth, surfaces, and material. The software just handles the drawing and record-keeping for you.
Amalgam Waste and Office Compliance
Charting amalgam restorations also intersects with regulatory requirements, particularly when fillings are being removed or replaced. Dental amalgam contains mercury, and the EPA finalized pretreatment standards in 2017 requiring dental offices that place or remove amalgam to install and maintain amalgam separators. These devices capture mercury and other metals before wastewater reaches the public sewer system. Offices must also avoid discharging scrap amalgam and must submit a one-time compliance report to their local control authority.
On the clinical safety side, the ADA has maintained mercury hygiene recommendations since 1999, covering proper ventilation, handling protocols, and mercury spill management in the dental office. When you chart an amalgam removal, documenting the procedure accurately matters not just for the patient’s dental record but for the office’s compliance trail as well.