Waiting for a dental injury to worsen, or for every consequence to become clear, can put a legal claim at risk. California doesn’t use a simple two-year deadline for dental negligence claims. In many cases, an injured patient has only one year from discovering the injury to begin an action.

I have practiced law for more than 35 years and am also a licensed dentist. That background informs how I review treatment timelines, dental records, and the point at which a patient had reason to investigate a possible injury. This article provides general California legal information, not legal advice for an individual situation.

California’s Filing Deadline for Dental Malpractice Claims

Most dental malpractice lawsuits are governed by California Code of Civil Procedure section 340.5. A professional-negligence claim against a health care provider, including a licensed dentist, must generally begin within three years after the date of injury or one year after the patient discovers, or reasonably should have discovered, the injury, whichever occurs first.

Professional negligence is a negligent act or omission in providing professional services that causes personal injury or wrongful death. Because the shorter deadline controls, a patient who learns of a likely dental injury six months after treatment shouldn’t assume the full three-year period remains available.

The date of injury isn’t always the date of the procedure. A harmful result may become apparent later, but later discovery doesn’t automatically extend the three-year outside limit. Determining which date applies requires a careful review of the records and sequence of events.

When Discovery Starts the One-Year Period

The discovery rule uses the date a patient actually discovered the injury or should have discovered it through reasonable diligence. Reasonable diligence means taking sensible steps to investigate when symptoms, treatment information, or another provider’s advice gives the patient reason to question what happened.

A patient doesn’t need a final diagnosis, a complete recovery prognosis, or proof of every future consequence before investigating a possible claim. Continuing pain after an extraction, numbness after anesthesia, a failed restoration, or a second dentist’s concern about prior treatment can mark important points in the timeline.

Preserve information that shows when those concerns arose, including:

• Treatment dates, provider names, and appointment summaries.
• Records already in your possession, including imaging, referrals, and follow-up instructions.
• A dated symptom history, photographs, bills, and communications with the dental office.
• Notes from second-opinion visits or later treatment that addressed the earlier work.

These materials don’t determine the deadline on their own. They can, however, clarify the difference between the treatment date and the date a patient first had reason to suspect an injury.

When the Three-Year Limit May Be Tolled

Section 340.5 identifies limited circumstances that can toll, or pause, the three-year outside limit for most adult claims. These include proof of fraud, intentional concealment, or a foreign body with no therapeutic or diagnostic purpose left in the injured person. An exception depends on the evidence in the case, not simply on the injury being discovered later.

Fraud and intentional concealment aren’t the same as a disagreement over treatment or an unfavorable result. Communications, records, and other information showing what was disclosed and when can be important when evaluating whether an exception applies.

Filing Deadlines for Children

Claims involving children follow separate statutory timing rules. In general, an action must begin within three years of the alleged wrongful act. For a child under six, the deadline is three years from the alleged wrongful act or before the child’s eighth birthday, whichever period is longer.

Parents shouldn’t assume that a child’s claim waits until adulthood. The applicable rule depends on the child’s age and the alleged wrongful act, making prompt review particularly important after a suspected injury involving pediatric dentistry, orthodontics, anesthesia, diagnosis, or treatment.

The Required 90-Day Notice Before Filing

California Code of Civil Procedure section 364 requires at least 90 days’ prior notice of an intention to sue before filing a professional-negligence action against a health care provider. The notice must identify the legal basis of the claim and the type of loss sustained, including the specific nature of the injuries.

This requirement doesn’t provide a general extra three months to file. If notice is served within the final 90 days before the applicable limitations period expires, section 364 extends the time to begin the action for 90 days from service of the notice. Serving notice earlier doesn’t independently add another 90 days to the filing deadline.

The notice period and the court filing deadline must therefore be assessed together. Waiting until a deadline appears close can affect both steps.

Steps to Take Before the Deadline

Create a timeline beginning with the original procedure or missed diagnosis and continuing through later symptoms, follow-up care, and second opinions. Keep copies of records, messages, and photographs without altering them. Dates recorded while events are fresh are usually more useful than a sequence reconstructed months later.

I handle dental malpractice matters involving:

• Alleged injuries from root canals.
• Extractions.
• Bridge and crown work.
• Failures to diagnose or treat a condition.
• Improper anesthesia administration.

In a case evaluation, I review the circumstances, available information, potential legal options, and timing issues affecting the California dental malpractice statute of limitations.

Documenting treatment dates, symptoms, and communications now creates a clearer record if the deadline becomes urgent. If you’re considering a dental malpractice lawyer in Santa Clarita, call The Law Office of Dean Schweitzer at to discuss a case evaluation.