2. Clinical dosimetry for dental specialties
Calculating and justifying every parameter
Dosimetry is the language that makes a PBM protocol reproducible. A protocol that cannot be recalculated by another clinician is not a protocol.
Clinical objectives
- • Calculate any missing parameter from the others.
- • Identify when a stated protocol is dosimetrically incomplete.
- • Adapt dose reasoning to intraoral versus extraoral application.
Dosimetric reasoning
- • Energy (J) = Power (W) × Time (s)
- • Area (cm²) = π × (diameter / 2)² — with diameter in cm
- • Fluence (J/cm²) = Energy (J) / Area (cm²)
- • Irradiance (W/cm²) = Power (W) / Area (cm²)
- • Total energy (J) = Energy per point × Number of points
Always calculate the actual treatment area. 'I use 2 J per point' does not describe a biological dose, because fluence depends on the area over which that energy is delivered.
Now apply: two protocols with identical energy and different spot sizes deliver different irradiance and can produce different biological responses.
Intraoral application shortens the optical path to the target; extraoral application must account for tissue thickness and attenuation. The same numeric fluence is not the same delivered dose.
Reporting only joules per point, omitting spot area, session count and interval — making the protocol unreproducible.
Knowledge checkpoint
Power 0.1 W, time 20 s, spot diameter 0.4 cm. What is the fluence?
Chapter summary
- • Energy without area is clinically incomplete.
- • Report wavelength, power, spot area, time per point, points, total energy, sessions and interval.
- • Recalculate before you copy any published protocol.
- • Systematic reviews and meta-analyses on PBM in dentistry — to be curated by the academic team.
- • International PBM/laser safety guidance applicable in the institution's jurisdiction.
- • Institutional clinical protocol documentation (where authorised).
Educational content only. These algorithms are educational decision-support tools and never autonomous medical decision-makers. Clinical decisions remain the responsibility of the treating professional. Certification within OHDR Study™ is not a university award unless an authorised institution has been formally configured.