What is a dental chair hour worth after supplies and lab work?
Illustrative case · Owner-dentist, three-room general practice in leased second-generation dental premises; preventive care, fillings and outsourced-lab crowns; no specialist surgery or sedation · United States; California regulatory case; no specific city or site assumed
Explore this business · Unit economics and KPIs
Use a completed treatment episode as the billing unit and clinician hours as the constrained resource. At the base payer mix, a crown produces $1,218.60 expected collectible fees and $901.54 contribution before paid labor, rent and debt across 105 chair minutes. A room itself earns nothing without a qualified clinician, a completed appointment and a collectible fee. Cash timing must still be modeled separately.
Define episodes instead of patients or list charges
The dentist appointment mix is 20.0% separate exam episodes, 50.0% filling episodes and 30.0% completed crown episodes. These are simplified families for planning; a real fee schedule contains individual codes, multiple surfaces, materials, clinical complexity and coverage limits. A crown episode includes preparation and seating, one lab charge and one combined fee. Hygiene is a separate bundled episode with a dentist check whose time is counted but whose fee is not added again.
One patient may have several episodes over time, so modeled episode totals are not unique patient counts. Fractions are expected monthly averages, not an instruction to book part of a patient. The clinical decision, treatment recommendation and consent precede financial scheduling; assumed contribution is not a reason to change appropriate care.
Calculate collectible contribution on the same basis
| Episode | Total slot time | FFS list fee | PPO allowed fee | Expected collectible fee | Contribution/episode | Contribution/hour |
|---|---|---|---|---|---|---|
| Exam | 30 minutes | $175.00 | $110.00 | $132.66 | $112.80 | $225.61 |
| Filling | 45 minutes | $425.00 | $285.00 | $332.46 | $285.81 | $381.07 |
| Crown | 105 minutes | $1,550.00 | $1,050.00 | $1,218.60 | $901.54 | $515.17 |
| Hygiene | 60 minutes | $225.00 | $150.00 | $175.50 | $155.04 | $155.04 |
For each row: collectible fee = FFS share × list fee × FFS realization + PPO share × allowed fee × PPO realization. Subtract procedure supplies, the crown laboratory amount where applicable, and steady processing at card share × processing rate. This is a steady-collection comparison; month-specific card fees follow actual bank receipts. Do not multiply every episode by the list charge or subtract fixed assistant wages again.
The crown calculation uses $80.00 supplies and $220.00 lab expense. Filling supplies are $42.00. These are unquoted case inputs, not sourced laboratory price lists. Replace them with the same clinical specification and lab remake/return terms used in the actual schedule. Production and expense boundaries.
Audit the owner clock and the hygiene handoff
The paid owner has 138.7 monthly clinical hours available and the hygienist has 138.7. Base booking and attendance leave 108.4 owner hours used in month 12. Hygiene’s 114.8 episodes require 11.5 owner check hours; only the remainder supports the dentist treatment mix. Ignoring those checks would overstate treatment revenue.
Weighted dentist episode slot time is 1.0 hours. An additional hygienist would create both additional payroll and additional owner check demand; a second doctor would need a different clinical-hour and pay model. Two owner rooms permit turnover but are not two concurrent owner production lines. The aggregate hours test cannot prove a collision-free daily appointment book, staff break compliance or a sterile instrument cycle. Validate with a timed day sheet and the actual qualified roster. Role/supervision boundary; Reprocessing sequence.
Read the contribution threshold correctly
At base month 12 the practice produces $74,285 collectible revenue and incurs $14,215 variable costs, with processing following actual receipts. For the same episode volumes in a steady month with no receivable growth, processing instead follows collectible revenue: total variable costs are $14,218, leaving $60,067 contribution. Payroll, fixed expenses and scheduled debt require $61,472. With unchanged payer mix, costs and attendance, the proportional throughput multiplier for cash break-even is 1.02x.
That translates to approximately 87.0% dentist and 92.1% hygiene booking before missed appointments. It is a continuous capacity illustration, not a rounded daily patient target, a regulatory limit or a current-year threshold after wage escalation. Because both streams and hygiene checks scale together, do not apply the multiplier to crowns alone. During opening, receivable growth and missed collections raise the cash requirement further.
Collect the observations that replace this worksheet
Track booked, attended and completed episodes separately by clinical family and payer. Record preparation/seating timestamps, hygiene-to-dentist handoff, turnover, reprocessing waits, no-shows, emergency interruptions, lab remakes, claim submission and payment dates. Preserve the failed periods, not only a smooth sample day. Never use patient-identifiable information in a public planning example.
Measure whether the roster can cover rooms, breaks, front-desk arrivals and claims work while preserving lawful duties. The $60.00 and $28.00 modeled wages exceed historical statewide medians of $58.00 and $23.18, but current local hiring and benefits remain unknown. Historical wage comparison. Use measured times and executed payer terms in a new model revision before financing extra capacity.
Sources and scope
- ADA: ownership and practice finances · Checked 2026-10-05 · Definitions of gross/adjusted production and collections; payer discounts, receivables and fixed/variable expenses. No ADA ratio is adopted as a mandatory underwriting standard.
- BLS California May 2023 occupational wages · Checked 2026-10-05 · Historical statewide hourly medians: dental hygienists 58.00; dental assistants 23.18. Model 60/28 hourly offers remain assumptions. May 2024 endpoint unavailable during check; no claim to latest local wages.
- Illustrative planning-case methodology · Checked 2026-10-05 · Case inputs are hypotheses, not national dental averages, patient demand, hiring quotes or signed commercial terms.
- CDC dental instrument reprocessing and surface disinfection · Checked 2026-10-05 · 2024-05-15 guidance: trained reprocessing responsibility, manufacturer instructions, monitoring and records. Supports workflow scope; not a California regulation substitute or cycle-throughput claim.
- Dental Hygiene Board of California: applicants and licensed duties · Checked 2026-10-05 · Official current applicant guidance: license category, permitted duties, required supervision and setting are defined by law. An employed RDH in a dentist-owned practice is the case; not an independent RDHAP business.