Pornprapapan, S. (2022). Factors affecting the deterioration of ball attachment system on dental implants in patients with implant-retained mandibular overdentures “Khao Aroi,” Kamphaeng Phet hospital. Journal of Nakornping Hospital, 13(2), 90–103. retrieved from https://he01.tci-thaijo.org/index.php/jnkp/article/view/259065