Shared Decision-Making for Periodontally Compromised Teeth: Study Protocol for an Ongoing Prospective Multicenter Before-and-After Clinical Trial

Treatment decisions for teeth with poor periodontal prognosis are often complicated, requiring careful balancing of clinical evidence and patient values.Shared decision-making (SDM) is increasingly recognized as a beneficial approach to align clinical judgment with patient preferences.However, structured SDM implementation in dental settings remains limited.This study was designed to evaluate the effectiveness of a structured SDM protocol compared to usual care decision-making for patients with severe periodontitis and hopelessprognosis teeth.A multicenter, before-and-after clinical trial will be conducted across 12 dental centers in South Korea.Each center will apply usual care decision-making for the first six months, followed by the SDM intervention for the subsequent six months.The SDM process involves a three-step model: team talk, option talk (aided by web-based decision aids), and decision talk.Eligible participants include patients with stage III or IV periodontitis and at least one hopeless-prognosis tooth.Each patient follows a three-visit schedule.Primary outcome is the rate of tooth preservation decisions.Secondary outcomes include measures related to SDM (SDM-Q-9, SDM-Q-Doc), patient experience (Perceived