Per hygienist, a modest edge over baseline.

The Headline

+2.5 pp

year-to-date edge in hygiene visits per hygienist-day vs comparable non-Park-Column offices. But the offices using the column most didn't improve more.

Park Column GP, YTD (per hygienist-day)

+1.9%

5.83 to 5.94 visits per hygienist-day, year-to-date 2026 vs 2025.

Control: non-Park-Column GP (24)

-0.6%

Comparable offices slipped over the same window. Net edge: +2.5 pp.

Usage vs improvement (correlation)

-0.14

No dose-response. Dormant offices improved most, not the heavy reporters.

What it means — in plain English

Normalized per hygienist, Park Column offices edged the baseline by +2.5 points year-to-date - but it isn't cleanly the column.

The right metric is visits per hygienist-day (matching SGA East), not per office - an office that adds a 4th hygienist shouldn't look busier just for the extra body. On that basis Park Column GP rose +1.9% YTD while comparable non-Park-Column offices slipped -0.6%, a +2.5 point edge. May alone was about flat (-0.4 pp).

But usage doesn't explain the edge. If the column caused it, heavy reporters should lead - instead regular reporters came in at +1.2%, occasional +0.2%, and dormant offices +5.4% (the highest), with a slightly negative correlation between usage and improvement. So the +2.5 pp is encouraging but not clearly the column at work.

Control offices run a higher absolute level (~7.9 vs ~5.9 per hygienist-day), so they're an imperfect comparator - read the year-over-year change, not the levels.

Methodology

Step-by-step

Step 1

Pull completed hygiene visits AND hygienist days worked per office from the Gen4 / SGA West PBI, for May and YTD Jan-May, 2026 vs 2025.

Step 2

Define Hygiene Visits per Hygienist-Day = completed hygiene visits (User Type = HYG) / hygienist days worked. This is FTE-normalized - it strips out headcount changes.

Step 3

Run the identical metric for a baseline: the 24 Active GP West offices that never rolled out the Park Column.

Step 4

Compare rollout vs baseline (difference-in-differences). If the column worked, rollout offices would beat the control.

Step 5

Within rollout offices, split by daily-form submissions (usage proxy) and correlate usage with the per-hygienist change.

Tier breakdown

Usage tiers vs control

Tier	Cohort	Metric
Dormant (0 subs)	11 offices	+5.4% YTD
Regular reporters (10+ subs)	22 offices	+1.2% YTD
Occasional (1-9 subs)	14 offices	+0.2% YTD

Control (non-Park-Column GP): -0.6% YTD. Park Column GP overall +1.9% = a +2.5 pp edge - but the tiers show no usage dose-response.

Supporting stats

Park Column GP, YTD

+1.9%

Control (non-PC GP), YTD

-0.6%

Net edge vs baseline, YTD

+2.5 pp

Net edge vs baseline, May

-0.4 pp

PC GP level (per hyg-day)

5.83 -> 5.94

Control level (per hyg-day)

7.93 -> 7.88

Usage vs improvement r

-0.14

Source

Gen4 SGA West PBI

Metric is visits per hygienist-day (FTE), matching SGA East. Cohorts aren't baseline-matched (control runs higher absolute productivity). CDT-level data still needed to isolate recovered slots.