1. Ellinger CW, Rayson JH, Henderson D. Single complete dentures. J Prosthet Dent. 1971; 26:4–10.
2. Prombonas AE, Vlissidis DS. Analysis of stresses in complete upper dentures with flat teeth at differing inclinations. Med Eng Phys. 2009; 31:314–319.
3. Chan MF, Närhi TO, de Baat C, Kalk W. Treatment of the atrophic edentulous maxilla with implant-supported overdentures: a review of the literature. Int J Prosthodont. 1998; 11:7–15.
4. Sadowsky SJ, Zitzmann NU. Protocols for the maxillary implant overdenture: A systematic review. Int J Oral Maxillofac Implants. 2016; 31:s182–s191.
5. Palmqvist S, Sondell K, Swartz B. Implant-supported maxillary overdentures: outcome in planned and emergency cases. Int J Oral Maxillofac Implants. 1994; 9:184–190.
6. Sadowsky SJ. The implant-supported prosthesis for the edentulous arch: design considerations. J Prosthet Dent. 1997; 78:28–33.
7. Kwon JU, Cho JH. Causes of failed implant attachments and application of double crown implant overdenture in one patient. J Korean Acad Prosthodont. 2018; 56:368–374.
8. Fanuscu MI, Caputo AA. Influence of attachment systems on load transfer of an implant-assisted maxillary overdenture. J Prosthodont. 2004; 13:214–220.
9. Seo JG, Cho JH. Causes of failures of long-term used double crown denture and new rehabilitation with dental implant and tooth combined denture using remaining teeth and implants. J Korean Acad Prosthodont. 2018; 56:384–390.
11. Feine JS, Carlsson GE, Awad MA, Chehade A, Duncan WJ, Gizani S, Head T, Lund JP, MacEntee M, Mericske-Stern R, Mojon P, Morais J, Naert I, Payne AG, Penrod J, Stoker GT Jr, Tawse-Smith A, Taylor TD, Thomason JM, Thomson WM, Wismeijer D. The McGill consensus statement on overdentures. Montreal, Quebec, Canada. May 24–25, 2002. Int J Prosthodont. 2002; 15:413–414.
12. Shahmiri R, Das R. Finite element analysis of implant-assisted removable partial denture attachment with different matrix designs during bilateral loading. Int J Oral Maxillofac Implants. 2016; 31:e116–e127.
13. Stawarczyk B, Beuer F, Wimmer T, Jahn D, Sener B, Roos M, Schmidlin PR. Polyetheretherketone-a suitable material for fixed dental prostheses? J Biomed Mater Res B Appl Biomater. 2013; 101:1209–1216.
14. Najeeb S, Zafar MS, Khurshid Z, Siddiqui F. Applications of polyetheretherketone (PEEK) in oral implantology and prosthodontics. J Prosthodont Res. 2016; 60:12–19.