Clean Gumline — Healthy Gingival Architecture
Healthy gingiva forms a tight pink collar around every tooth.
- 1–3 mm: Healthy sulcus depth (shallow gum pocket)
- Coral pink: Gingival color (stippled surface)
- 0%: Bleeding on probing (no vessel exposure)
- <12 hrs: Biofilm turnover (brushing removes it)
The healthy periodontium
Gum tissue seals tightly against enamel at the gumline.
Sulcus and junctional epithelium
A shallow groove and thin epithelium guard the tooth root.
A clean mouth resets bacterial load within hours.
Plaque Accumulation Along the Tooth-Gum Margin
Bacteria colonize the enamel pellicle and organize into a sticky film.
- 4–12 hrs: Plaque formation start (after cleaning)
- 700+: Bacterial species (in dental biofilm)
- <24 hrs: Biofilm thickness (young supragingival film)
- ~10 days: Mineralization onset (plaque hardens to calculus)
Pellicle and early colonizers
Streptococci attach first to the salivary protein film.
Biofilm maturation
Layered colonies thicken fastest near the gum margin.
Missed brushing lets biofilm mass double daily.
Bacterial Toxin Release Into Gingival Tissue
Mature biofilm bacteria shed toxins that breach the gum barrier.
- LPS: Key toxin class (lipopolysaccharide endotoxin)
- Proteases: Enzymes released (degrade tissue proteins)
- ↑ Rising: Epithelial permeability (barrier weakens)
- Hours: Host response trigger (to first immune signal)
Endotoxin diffusion
Toxins seep through the thin junctional epithelium.
Early immune signaling
Local cells release cytokines calling for defense.
Toxin load, not bacteria count, drives early damage.
Inflammatory Response — Redness and Swelling
Blood vessels dilate, gingiva swells, tissue turns bright red.
- Marked: Vessel dilation (increased blood flow)
- ↑ Edema: Gingival volume (fluid leaks into tissue)
- Neutrophils: Immune cells present (first responders)
- None: Bone involvement (gingivitis stays reversible)
Vasodilation and edema
Capillaries widen, plasma leaks, tissue puffs outward.
Still fully reversible
No attachment or bone loss has occurred yet.
This stage resolves within days of proper hygiene.
Bleeding Gingivitis — The Hallmark Symptom
Fragile dilated vessels rupture at the lightest probing or brushing.
- Positive: Bleeding on probing (classic diagnostic sign)
- None: Pocket depth change (no attachment loss)
- 100%: Reversibility (with plaque control)
- ~7–14 days: Time to resolve (consistent hygiene)
Why gums bleed
Thin inflamed epithelium exposes engorged capillaries.
Gingivitis versus periodontitis
No bone loss keeps this stage entirely reversible.
Removing plaque restores healthy pink gingiva within two weeks.