The Spot-Dam Technique: A Protocol for Adhesive Cementation of BOPT Crowns

The Biologically Oriented Preparation Technique (BOPT) uses vertical tooth preparation without a defined finish line, guided by provisional restorations to shape the gingival emergence profile. Subgingival crown margins inherent to BOPT increase the risk of residual cement and soft-tissue trauma during adhesive cementation. This article presents the Spot-Dam Technique (SDT), a continuous or staged isolation protocol designed to enhance visibility, facilitate excess cement removal, and protect peri-gingival tissues in BOPT restorations.

SDT employs localized rubber dam fragments stabilized with polytetrafluoroethylene (PTFE) tape during water-airborne-particle abrasion (WAPA) of dentin, followed by sulcular isolation during crown seating. Zirconia crowns were conditioned with air-particle abrasion, and self-adhesive resin cement was applied. Excess cement was removed at the gel stage to minimize soft-tissue trauma. The protocol integrates soft-tissue protection, dentin pretreatment, restoration surface conditioning, and controlled cement removal to optimize adhesion and margin integrity in subgingival restorations.

The SDT provides a reproducible workflow for adhesive cementation of BOPT crowns. Isolation with rubber dam and PTFE tape protects peri-gingival tissues, facilitates complete cement removal, and preserves seating accuracy, supporting biological stability and prosthetic predictability in vertically prepared teeth.

Subgingival crown margins inherent to the BOPT increase the risk of sulcular cement retention and soft-tissue trauma during definitive cementation. The isolation strategy described in the current manuscript combines sulcular displacement and contamination control to improve visibility, facilitate cement removal, and protect peri-gingival tissues during adhesive cementation of indirect restorations to vertically prepared teeth.