Most adults over forty have at least one silver filling, and many have several. Meanwhile, virtually every filling placed today is tooth-colored composite. That shift raises two questions patients ask constantly: is composite genuinely better, and should the old silver fillings be replaced?
One of these questions has a clear clinical answer and the other has a firmly qualified one.
Key Factors to Understand About Filling Materials
1. The Difference That Actually Matters Is Bonding
Composite bonds chemically to the tooth. That means only the decayed tissue needs removing, since the material adheres to what remains.
Amalgam is held mechanically. It does not bond to anything; it stays in place because of the shape of the cavity. That requires cutting away additional healthy tooth structure to create an undercut that grips the filling.
This difference compounds across a lifetime. Every millimeter of healthy tooth preserved today is a millimeter you still have in twenty years, when the question becomes whether that tooth needs a crown or can take another filling.
2. Where Amalgam Still Holds an Advantage
Amalgam is durable. It typically lasts ten to fifteen years against composite seven to twelve, it is less technique-sensitive to place, and it tolerates moisture better, which matters for a deep filling at the gumline on a back molar. It is also less expensive, typically $120 to $300 against composite $180 to $450.
Composite counter-advantages are substantial: it preserves more tooth, it does not conduct temperature the way metal does, it does not expand and contract in a way that contributes to cracks over decades, and it is invisible.
3. Should You Replace Existing Silver Fillings?
The straight answer is: not automatically.
The mercury within a stable, intact amalgam filling is bound in the alloy. Major dental and regulatory bodies consider existing amalgam fillings safe to leave in place. Drilling one out unnecessarily releases more mercury vapor than leaving it alone does, and removes additional healthy tooth structure.
Replacement is warranted when the filling is cracked, leaking or has decay developing underneath it, when a crack line has developed in the tooth around the filling, when the filling is loose or margins are visibly open, when it shows when you smile and you want that changed, or when other work is being done on the same tooth anyway.
Replacement is not warranted simply because a filling is old and silver. If a practice proposes replacing all of your amalgams at once in a mouth with no symptoms, that is selling rather than treating.
4. What Determines How Long Any Filling Lasts
Grinding. Bruxism wears and fractures fillings faster than anything else. A night guard protects them.
Cleaning the margins. New decay begins at the edge of an old filling, not in the filling itself.
Sugar frequency rather than quantity. Six sips of a soft drink across an afternoon is considerably more damaging than the same drink in ten minutes, because each exposure restarts the acid attack.
Regular examinations. A filling beginning to leak, caught early, is a simple replacement. Left alone it becomes decay under the filling, then a crown, then potentially a root canal.
Everyday Real-Life Scenarios: Material Decisions in Practice
Scenario A: The Unnecessary Replacement Avoided
A patient arrives requesting that all eleven of their amalgam fillings be replaced after reading about mercury online. Examination and x-rays show nine are entirely intact with sound margins and no decay beneath. Two show marginal breakdown with early decay. Those two are replaced; the other nine are left and monitored.
Scenario B: The Filling That Should Have Been a Crown
Another patient has a very large old amalgam occupying most of a molar, with thin remaining walls. A composite replacement would leave the same structurally weak walls unsupported. The recommendation is an onlay or crown to provide cusp coverage instead.
Scenario C: The Small Cavity Caught Early
A third patient attends routine examinations, and a small cavity is identified on an x-ray between two molars while still confined to enamel. It is entirely painless. A conservative composite filling takes thirty minutes and preserves nearly all the tooth. Left until it caused symptoms, the same tooth would likely have needed root canal treatment and a crown.
Frequently Asked Questions About Fillings
Q1: Are silver fillings dangerous?
A: Major dental and regulatory bodies consider intact amalgam fillings safe to leave in place, as the mercury is bound within the alloy. The clinical consensus is that removing sound amalgam fillings unnecessarily does more harm than leaving them.
Q2: How long do tooth-colored fillings last?
A: Typically seven to twelve years, and often longer for small fillings in patients who do not grind. Amalgam averages somewhat longer, but composite preserves more of your natural tooth in the first place, which usually matters more across a lifetime.
Q3: How soon can I eat after a composite filling?
A: The composite is fully hardened by the curing light during your appointment. Wait only until the numbness wears off, usually two to three hours, so you do not accidentally bite your cheek or tongue.
Q4: My filling feels high when I bite. Should I wait for it to settle?
A: No. It should be adjusted. A filling even fractions of a millimeter too tall concentrates your entire bite force onto a single point, causing soreness and over time potential cracking. Correcting it takes about a minute.
Why Choose NoHo Dental Group for Fillings?
At NoHo Dental Group on Chandler Blvd, we place composite fillings exclusively and are a mercury-free practice. More importantly, we are conservative about when a filling is needed and honest about when an existing one should be left alone.
Why North Hollywood Patients Trust Us:
- Conservative by Default: We remove decay, not healthy tooth, and do not propose replacing sound fillings.
- Layered and Cured Properly: Composite placed in thin increments controls shrinkage stress, the main cause of post-operative sensitivity.
- Bite Checked Before You Leave: Every filling verified and adjusted, every time.
- Specialists on Site: If a cavity reaches the nerve, our endodontist Dr. Kakoli is in the building.
Contact our friendly team today to schedule your examination.
