Cyanoacrylate Adhesives in the Dental Lab: Bob Smith Industries Product Guide
Cyanoacrylate (CA) adhesives are everyday tools in the dental lab — die repair, model fragment bonding, scan abutment tacking, and small-part fixturing during milling. Bob Smith Industries (BSI) manufactures a range of industrial cyanoacrylate products that have found a strong following in dental lab applications for their consistent quality and range of viscosities. Here's a practical guide to what BSI products are used for and how to choose between them.
Why CA Viscosity Matters
Cyanoacrylate adhesives cure by polymerization triggered by surface moisture. Viscosity is the primary selection criterion because it determines how the adhesive behaves in your application:
- Thin/low viscosity: Flows into tight gaps by capillary action; cures quickly; good for fitting surfaces together first, then wicking adhesive in
- Medium viscosity: General purpose; some gap filling; slightly more working time
- Thick/gel: Gap filling; doesn't run; useful for vertical surfaces or larger gaps; longer working time
BSI Product Lines for Dental Lab Applications
| Product | Viscosity | Dental Lab Application |
|---|---|---|
| BSI-201 Insta-Cure+ | Very thin | Die hardening, capillary penetration into tight cracks |
| BSI-202 Super-Gold+ | Thin-medium | General die repair, fragment bonding with good surface contact |
| BSI-203 Insta-Cure+ (Maxi-Cure) | Medium-thick | Gap filling, model repair with slight misfit |
| BSI-157 Maxi-Cure Gel | Gel | Thick gap filling, fixture bonding, non-run applications |
Specific Dental Lab Applications
Die Repair
Small chips on stone or plaster dies are repairable with thin CA. The procedure: clean the chipped area, apply a drop of thin CA, allow to wick in and cure, then trim or dress the area to restore die contour. Thin adhesive penetrates the porous stone and creates a hard bond. Don't use thick CA for this — it won't penetrate and will create a surface lump instead.
Model Fragment Repair
Broken stone models (especially die stumps that separate from the base) are routinely repaired with CA. Dry-fit the pieces first, then apply thin CA to one surface and assemble. The fit should be precise — CA doesn't significantly gap-fill without using a thicker formulation.
Scan Body Tacking / Temporary Fixation
Some labs use small amounts of CA to temporarily stabilize components in a model for scanning purposes. Thin CA applied in tiny amounts can hold a component without the permanence or mess of other adhesives.
Accelerators
BSI and other CA manufacturers offer accelerator sprays (BSI-151, BSI-156) that dramatically speed cure time — from minutes to seconds. Useful when you need fast turnaround. Note: accelerated cures sometimes produce slightly more brittle bonds than natural-cure; use accelerators for less structurally demanding applications.
Handling and Storage
- Store at room temperature or cooler; refrigeration extends shelf life significantly
- Keep caps tight; CA cures by moisture exposure — open bottles cure from the tip inward over time
- Use the smallest drop necessary; CA adhesives are used in thin films, not thick beads
- Use in ventilated areas — cyanoacrylate fumes can irritate eyes and mucous membranes
- Debonding: hardened CA can be loosened with acetone (acetone-based nail polish remover works)