When dentists want an independent opinion on a curing light, many look to Dr. Richard Price. In August 2025 he put the Woodpecker X-Star LED curing light through his laboratory testing and compared it with the Ultradent VALO® X. His conclusion: the X-Star rivals the VALO X in light output and beam quality at a fraction of the price, and it is the best budget curing light he has tested.
Here's a summary of his report. You can also read Dr. Price's full report (PDF).
Who is Dr. Richard Price?
Dr. Richard Price, BDS, DDS, PhD, is a prosthodontist and professor at the Faculty of Dentistry at Dalhousie University in Halifax, Canada, where he has taught since 1984. He is one of the most widely cited researchers on dental curing lights and light curing of resin composites.
- More than 200 peer-reviewed publications, many on curing lights and resin polymerization
- Co-author of the Light Curing chapter in Sturdevant's Art and Science of Operative Dentistry (7th edition)
- Recipient of the IADR Dental Materials Group Peyton Skinner Award (2019) and the Canadian Dental Association Honored Member Award (2023)
- Lectures internationally on getting the most from your curing light
Why "how powerful is it?" is a tricky question
Curing lights are often marketed by irradiance (mW/cm²). Dr. Price points out that irradiance can be misleading. If two lights deliver the same total power, the one with the smaller tip shows a much higher irradiance. Halving the tip diameter increases irradiance about fourfold. Many dental radiometers also measure only the center of the beam, which favors lights with a bright center spot.
That's why he measures total power output in a laboratory integrating sphere, then calculates the average irradiance over the actual tip area. He also measures the emission spectrum, the beam profile across the tip, and output at increasing distances.
How he tested the X-Star
- Power and spectrum: a 6-inch integrating sphere connected to a laboratory-grade fiber-optic spectrometer, accurate to within ±10% of a NIST reference standard.
- Tip area: internal tip diameter measured with a digital caliper.
- Distance: output measured every 1 mm away from a fixed 6 mm aperture.
- Beam uniformity: a laser beam profiler to map how evenly blue and violet light are spread across the tip.
He tested three X-Star units and compared them with the VALO X, the earlier Woodpecker LED-B, and other VALO lights.
Key results: X-Star vs. VALO X
| Light | Tip diameter | Standard mode: power / irradiance | Highest mode: power / irradiance |
|---|---|---|---|
| Woodpecker X-Star (L2555571XR) | 11.8 mm | 1,180 mW / 1,083 mW/cm² | 2,963 mW / 2,718 mW/cm² |
| Ultradent VALO X | 12.5 mm | 1,330 mW / 1,084 mW/cm² | 2,750 mW / 2,241 mW/cm² |
| Woodpecker LED-B (for reference) | 7.0 mm | 356 mW / 925 mW/cm² | None |
Source: Dr. Richard Price, "The Woodpecker X-Star Curing Light," August 2025.
What the numbers mean
- Power that rivals the VALO X. In standard mode the X-Star delivered essentially the same average irradiance as the VALO X. In its highest mode it delivered more power, and higher irradiance, than the VALO X.
- Meets the ISO standard. Irradiance was within about 10% of Woodpecker's stated specifications, well within the ISO 10650 tolerance of ±20%. All three X-Star units Dr. Price tested met ISO 10650.
- Similar spectrum, more blue. The X-Star has two emission peaks and the VALO X has three, but overall coverage is similar. The X-Star delivers more power in the blue region, which penetrates composite better than violet light. Dr. Price expects this could help the X-Star outperform the VALO X, though he notes further testing is needed to confirm it.
- Beam profile as good as or better than the VALO X. Blue light is well distributed across the tip, and violet light is more evenly distributed than on the VALO X.
- Strong output at a distance. Performance over distance was similar to, if not better than, the VALO X, and much better than the LED-B.
- A large 11.8 mm tip, similar to the VALO Grand, for broad coverage of the restoration.
Design and ergonomics
- Wand-style design: like the VALO X, the X-Star has no light guide, so you can position it directly over restorations in every area of the mouth, including the last molars.
- Rotating head for access.
- Induction charging with a built-in radiometer in the charging base, so you can check output any time.
- Two batteries included.
- 8 modes: Normal, High, Turbo, Ortho, Soft (ramp), Pulse, Check and Diagnostic (white light). It also has a lower-heat option.
What Dr. Price recommends watching
Dr. Price's reports are respected because they're candid, and this one is no exception. He noted:
- A slight instability in output compared with the VALO X's very steady output. He wasn't sure it matters clinically.
- On his unit, output in Ortho mode sometimes dropped after the fourth pulse, possibly from heating.
- In its highest mode the X-Star stays on continuously, while the VALO X pulses. The X-Star may produce more heat, which he says needs more study.
- The VALO X has better construction quality and sealing. The X-Star has no seal at the tip ring or the battery, and only a simple O-ring at the rotating head. He recommends that Woodpecker add seals.
- The VALO X comes with a 5-year warranty.
- Durability and battery life were not tested.
As with any high-power curing light, use care with the wide tip to avoid heating the gingival tissues.
The bottom line
Dr. Price concluded that the X-Star is the best Woodpecker light he has tested and the best budget curing light he has tested. It offers good performance at a much lower price than the VALO X. In his report he listed the VALO X at about $2,200, compared with the X-Star at GoldenDent.
For practices that want VALO-class power, a wide tip and a good beam profile without the premium price, the X-Star is a strong value.
Shop the Woodpecker X-Star Curing Light →
Download Dr. Price's full X-Star report (PDF)
Frequently asked questions
Is the Woodpecker X-Star as powerful as the VALO X?
In Dr. Richard Price's laboratory testing, the X-Star matched the VALO X's average irradiance in standard mode (about 1,083 vs. 1,084 mW/cm²). In its highest mode it delivered more power and higher irradiance than the VALO X.
Does the X-Star meet ISO standards?
Yes. All three X-Star units Dr. Price tested were within the ISO 10650 standard of ±20% of the stated output.
What tip size does the X-Star have?
Dr. Price measured an 11.8 mm internal tip diameter, close to Woodpecker's stated 12 mm and similar to the VALO Grand.
Who is Dr. Richard Price?
Dr. Richard Price is a prosthodontist and professor at Dalhousie University in Canada. He is a leading researcher on dental curing lights and light curing, with more than 200 peer-reviewed publications.
Summary based on "The Woodpecker X-Star Curing Light" by Dr. Richard Price (August 2025). Results reflect the units he tested at that time. VALO® is a registered trademark of Ultradent Products, Inc. GoldenDent is not affiliated with or endorsed by Ultradent.
