Objectives: The aim of this observational study was to evaluate decision regret after shared decision making regarding pain control for scaling and root-planing (SRP). The decision regret scale was used as the primary outcome and pain control and future choice as secondary outcomes. Methods: 159 patients with a need for SRP during anti-infective therapy or as retreatment in periodontal supportive therapy opted for pain control using a decision board during shared decision making. Pain control options were: (1) no anaesthesia (NO), (2) intrapocket gel (GEL, Oraqix, Dentsply Sirona), and (3) injected anaesthesia (INJ, articaine 4%, Ultracain D-S, Sanofi-Aventis). The decision regret scale, procedural pain (via VAS), and future choice were recorded after SRP by questionnaire. Results: 88 patients opted for anaesthesia, 73 of them for intrapocket gel, and 15 for injection. Overall, patients were satisfied with their choice (98%), reported no regret (94%), and would take the same decision for future treatments (96%). Additionally, they valued their choice as smart (97%) and not harmful (97%). These outcomes were consistent for the subgroups, showing no intragroup differences (p>.05). The distribution of anaesthesia choice was affected by treatment point (p=.000). 80% choosing INJ underwent anti-infective therapy, and 65% opting for GEL received retreatment during supportive therapy. Procedural pain during SRP was distributed equally between the groups (p>.05), with an overall mean of 20.5±23.0 and a range between 0 to 90. Future choice of pain control was not influenced by procedural pain (p=.155). Conclusion: Decision-board-supported shared decision making for pain control during SRP led to satisfaction with the anaesthesia choice, overall and in each subgroup. Patients were able to properly estimate their individual need for adequate pain control. Patients undergoing supportive periodontal therapy with a need for SRP tend to choose intrapocket gel or no anaesthesia without regretting the decision. Palabras clave: shared decision making, decision regret, periodontal disease, intrapocket anaesthesia