Radiation dose, in context
Parents rightly worry about radiation exposure in kids. The honest answer is that modern digital dental x-rays use about 90% less radiation than the old film versions your grandparents remember — and the dose from a set of kids' bitewings is smaller than the natural background radiation you get on a 2-hour flight.
That said, "low" isn't "zero" — and the right question isn't "should my kid have x-rays?" but "how often, and for what?" Here's the honest framework.
The actual numbers
Radiation is measured in microsieverts (µSv). For context:
- Background radiation (just being alive in Australia, per day): ~7 µSv
- One digital bitewing x-ray: ~1-2 µSv
- Set of 2 bitewings (what we take for a child): ~2-4 µSv
- Panoramic x-ray (full mouth, occasional): ~15 µSv
- 2-hour flight: ~20-30 µSv
- Chest x-ray: ~100 µSv
A set of bitewings is less radiation than an afternoon at the beach. It also sees things that a visual exam can't — and missing a cavity between teeth means it grows for 12 months before we catch it.
What x-rays actually show us
Three things x-rays reveal that we can't see any other way:
- Cavities between teeth — the most common cavity site in kids, and completely hidden from visual exam
- Adult teeth forming under baby teeth — any developmental issues, missing adult teeth, or positioning problems
- Abscesses and cysts — infections at the tip of the root that don't cause visible symptoms until they're large
When we DON'T take x-rays on kids
At Berala Dental we follow an "as low as reasonably achievable" (ALARA) principle:
- Never routinely for under-3s — only if specific concern
- Not at every visit — the "annual x-ray" default used to be routine; we've moved to risk-based frequency
- Not if the last set was recent — we ask other practices for previous x-rays rather than repeating
- Not for kids with excellent hygiene and no cavity history — we might go 2+ years between sets
When x-rays are genuinely important
- First visit — baseline images, unless the child is clearly low-risk
- After trauma — to check for root fractures
- Before dental treatment — we need to see what we're treating
- Persistent toothache with no visible cause
- Orthodontic planning — adult teeth positioning and wisdom teeth assessment
The trade-off in one line: the radiation dose from modern digital bitewing x-rays is tiny (less than an afternoon at the beach), while the cavities and issues those x-rays catch — especially between teeth, where visual exam can't see — can progress silently for months. Published paediatric dental guidelines consistently support risk-based x-ray frequency rather than routine or never.
How we protect kids during x-rays
- Digital sensors — significantly less radiation than old film (typical reductions of around 80-90% are documented in dental radiography literature)
- Lead apron + thyroid collar — every time, no exceptions
- Paediatric-size sensors — smaller, more comfortable, more accurate
- Focused beam — only the area we're imaging, not the whole face
- No repeats — we get it right first time using digital previews
What's covered by Medicare CDBS
Good news: bitewing x-rays are fully covered under CDBS for eligible kids. There's no "should we skip x-rays to save money" calculation — they're already paid for if your child qualifies. See our CDBS explainer for how it works, or the Fees page for the full cover picture.