Technical note: clinical observations of a modified BOPT protocol with advanced surface refinement

This uncontrolled prospective case series evaluated the 12-month biological and periodontal outcomes of a novel modified Biologically Oriented Preparation Technique (BOPT). This protocol specifically integrated piezoelectric subgingival finish-line refinement, subgingival mechanical polishing, and four-step ultra-polished zirconia restorations to optimize gingival thickness (GT), marginal positional stability, and peri-restorative tissue health. Four patients requiring fixed prostheses (totaling 35 teeth) were treated using this integrated modified BOPT framework. Following bulk tooth reduction, finish lines were refined using specialized piezoelectric ultrasonic tips and smoothed subgingivally with silicone points. The subgingival emergence profiles of definitive zirconia crowns were managed through a strict four-step ultra-polishing protocol. Periodontal variables-including GT changes across different baseline phenotypes, gingival margin stability, plaque index, bleeding on probing, and gingival stippling-were recorded at baseline, 1 week, 3, 6, and 12 months. At 12 months, stable gingival margins were maintained with no observable tissue recession across all monitored sites. A notable descriptive increase in GT occurred, particularly within the baseline thin phenotype group, which shifted from 0.59 ± 0.09 mm to 1.14 ± 0.23 mm. Furthermore, favorable soft-tissue responses were observed, characterized by minimal bleeding scores and a widespread clinical reappearance of gingival stippling at the 1-year follow-up interval. Within the study's limitations, this modified BOPT protocol demonstrated promising trends regarding soft-tissue thickening and short-term marginal stability. Integrating piezoelectric refinement with rigorous clinical and laboratory zirconia polishing protocols exhibits excellent biological integration and soft-tissue maturation. Incorporating piezoelectric finishing tools, subgingival silicone polishing, and meticulous zirconia ultra-polishing within a BOPT philosophy offers a tissue-friendly, biologically guided approach that effectively supports peri-restorative tissue harmony and phenotype stability around fixed restorations.