Siriphan, Ratchatawan, Kanoknadda Tavedhikul, and Attawood Lertpimonchai. 2021. “Periodontitis Progression and Prognostic Factors in Questionable Teeth During Supportive Periodontal Therapy”. Khon Kaen University Dental Journal 24 (3):27-37. https://he01.tci-thaijo.org/index.php/KDJ/article/view/247708.