Estela Vargas, CRDH, CEO Remote Sourcing
Before considering coding for reimbursement by insurance plans for inlays, onlays, and ¾ crowns, you must know how they are defined in the Current Dental Terminology by the American Dental Association(ADA). Coding what you do is the rule, but you must know if what you think you are coding is precisely what was performed on the patient, particularly when it comes to inlays, onlays, and 3/4 crowns.
Many insurance coordinators will see a code for a procedure on a treatment plan, but little documentation supports the clinical notes’ choice. If it isn’t in the notes, it didn’t happen. Consult the Current Dental Terminology manual from the ADA for the codes and their descriptors and nomenclature. Meet with the clinical team to ensure proper notes are in the patients’ chart.
Inlays, onlays, and 3/4 crowns are defined as “indirect” restorations because they are fabricated outside of the mouth through the use of impressions that are physical or digital. The remaining healthy tooth structure is a determining factor in restoration choice. If all cusps are intact, many dentists choose an inlay if it is more appropriate than a filling. An onlay will cover one or more missing cusps (this must be in the narrative). ¾ crowns cover all of the cusps on posterior teeth, extend beyond the height of contour on the covered surfaces and restore three of the four proximal surfaces.
Many PPO plans have an “alternate benefit clause” for direct restorations if the proof has not been presented for indirect restorations. Some PPO plans have a LEAT clause that dictates only the cheapest alternative treatment will be paid. The cheapest material is often amalgam. Other plans exclude inlays as not a covered benefit even if warranted by clinical notes.
Many plans require that two or more cusps of a tooth be involved in the onlay and may specify how much of the cusp incline must be involved (usually 80 percent or more) to qualify for benefits.
Benefits of a dental inlay are to conserve much more of the tooth structure, not as much drilling is required to prep the tooth, and inlays can help increase the tooth strength by 50 percent, repair small fissures and secure the structural integrity of a tooth.
The value is there for the inlay, and usually, no one wants amalgam because it is unsightly and contains silver, tin, and copper metals and 50% mercury*. However, when the patient learns that their plan benefits will not cover an inlay, they often choose the least expensive alternative, amalgam.
Often the plan policy dictates that 50% more of the tooth structure must be missing before an indirect restoration is adjudicated for payment. The patient who only wants what the insurance will pay often gets an extensive filling or some interim restoration with a guarded long-term prognosis due to the chewing forces of the posterior molars.
