J Adv Prosthodont.  2016 Feb;8(1):9-15. 10.4047/jap.2016.8.1.9.

A study on the changes in attractive force of magnetic attachments for overdenture

• Leem HW
• Cho IH
• Lee JH
• Choi YS

• KMID: 2393190
• DOI: http://doi.org/10.4047/jap.2016.8.1.9

Abstract

PURPOSE
Although magnetic attachment is used frequently for overdenture, it is reported that attractive force can be decreased by abrasion and corrosion. The purpose of this study was to establish the clinical basis about considerations and long term prognosis of overdenture using magnetic attachments by investigating the change in attractive force of magnetic attachment applied to the patients.
MATERIALS AND METHODS
Among the patients treated with overdenture using magnetic attachments in Dankook University Dental Hospital, attractive force records of 61 magnetic attachments of 20 subjects who re-visited from July 2013 to June 2014 were analyzed. Dental magnet tester (Aichi Micro Intelligent Co., Aichi, Japan) was used for measurement. The magnetic attachments used in this study were Magfit IP-B Flat, Magfit DX400, Magfit DX600 and Magfit DX800 (Aichi Steel Co., Aichi, Japan) filled with Neodymium (NdFeB), a rare-earth magnet.
RESULTS
Reduction ratio of attractive force had no significant correlation with conditional variables to which attachments were applied, and was higher when the maintenance period was longer (P<.05, r=.361). Reduction ratio of attractive force was significantly higher in the subject group in which attachments were used over 9 years than within 9 years (P<.05). Furthermore, 16.39% of total magnetic attachments showed detachment of keeper or assembly.
CONCLUSION
Attractive force of magnetic attachment is maintained regardless of conditional variables and reduction ratio increased as the maintenance period became longer. Further study on adhesive material, attachment method and design improvement to prevent detachment of magnetic attachment is needed.

Keyword

Magnetic attachment; Overdenture; Attractive force

MeSH Terms

Adhesives
Corrosion
Denture, Overlay*
Effect Modifier, Epidemiologic
Humans
Neodymium
Prognosis
Steel
Adhesives
Neodymium
Steel

Reference

1. Haraldson T, Karlsson U, Carlsson GE. Bite force and oral function in complete denture wearers. J Oral Rehabil. 1979; 6:41–48.

2. Osterberg T, Carlsson GE. Symptoms and signs of mandibular dysfunction in 70-year-old men and women in Gothenburg, Sweden. Community Dent Oral Epidemiol. 1979; 7:315–321.

3. Ellis JS, Pelekis ND, Thomason JM. Conventional rehabilitation of edentulous patients: the impact on oral health-related quality of life and patient satisfaction. J Prosthodont. 2007; 16:37–42.

4. Turkyilmaz I, Company AM, McGlumphy EA. Should edentulous patients be constrained to removable complete dentures? The use of dental implants to improve the quality of life for edentulous patients. Gerodontology. 2010; 27:3–10.

5. Miller PA. Complete dentures supported by natural teeth. J Prosthet Dent. 1958; 8:924–928.

6. Morrow RM, Feldmann EE, Rudd KD, Trovillion HM. Tooth-supported complete dentures: an approach to preventive prosthodontics. J Prosthet Dent. 1969; 21:513–522.

7. Lord JL, Teel S. The overdenture: patient selection, use of copings, and follow-up evaluation. J Prosthet Dent. 1974; 32:41–51.

8. Morrow RM, Powell JM, Jameson WS, Jewson LG, Rudd KD. Tooth-supported complete dentures: description and clinical evaluation of a simplified technique. J Prosthet Dent. 1969; 22:415–424.

9. Dodge CA. Prevention of complete denture problems by use of "overdentures". J Prosthet Dent. 1973; 30:403–411.

10. Ettinger RL, Taylor TD, Scandrett FR. Treatment needs of overdenture patients in a longitudinal study: five-year results. J Prosthet Dent. 1984; 52:532–537.

11. Parel SM. Implants and overdentures: the osseointegrated approach with conventional and compromised applications. Int J Oral Maxillofac Implants. 1986; 1:93–99.

12. Crum RJ, Rooney GE Jr. Alveolar bone loss in overdentures: a 5-year study. J Prosthet Dent. 1978; 40:610–613.

13. Rissin L, House JE, Manly RS, Kapur KK. Clinical comparison of masticatory performance and electromyographic activity of patients with complete dentures, overdentures, and natural teeth. J Prosthet Dent. 1978; 39:508–511.

14. Reitz PV, Weiner MG, Levin B. An overdenture survey: preliminary report. J Prosthet Dent. 1977; 37:246–258.

15. Fenton AH, Hahn N. Tissue response to overdenture therapy. J Prosthet Dent. 1978; 40:492–498.

16. Thayer HH, Caputo AA. Photoelastic stess analysis of overdenture attachments. J Prosthet Dent. 1980; 43:611–617.

17. Stansbury BE. A retentive attachment for overdentures. J Prosthet Dent. 1976; 35:228–230.

18. Quinlivan JT. An attachment for overlay dentures. J Prosthet Dent. 1974; 32:256–261.

19. Khoo HD, Chai J, Chow TW. Prosthetic outcome, patient complaints, and nutritional effects on elderly patients with magnet-retained, implant-supported overdentures-a 1-year report. Int J Oral Maxillofac Implants. 2013; 28:1278–1285.

20. Gillings BR. Magnetic retention for complete and partial overdentures. Part I. J Prosthet Dent. 1981; 45:484–491.

21. Taira Y, Hai K, Matsumura H, Atsuta M. Adhesive bonding of titanium nitride-plated stainless steel for magnetic attachments. Eur J Oral Sci. 2001; 109:204–207.

22. Gillings BR. Magnetic retention for overdentures. Part II. J Prosthet Dent. 1983; 49:607–618.

23. Naert I, Quirynen M, Theuniers G, van Steenberghe D. Prosthetic aspects of osseointegrated fixtures supporting overdentures. A 4-year report. J Prosthet Dent. 1991; 65:671–680.

24. Riley MA, Williams AJ, Speight JD, Walmsley AD, Harris IR. Investigations into the failure of dental magnets. Int J Prosthodont. 1999; 12:249–254.

25. Naert I, Alsaadi G, Quirynen M. Prosthetic aspects and patient satisfaction with two-implant-retained mandibular overdentures: a 10-year randomized clinical study. Int J Prosthodont. 2004; 17:401–410.

26. Behrman SJ, Egan GF. The implantation of magnets in the jaw to aid denture retention : An original brief research report. New York State Dent J. 1953; 19:353–371.

27. Freedman H. Magnets to stabilize dentures. J Am Dent Assoc. 1953; 47:288–297.

28. Winkler S, Pearson MH. The effectiveness of embedded magnets in complete dentures during speech and mastication: a cineradiographic study. Dent Dig. 1967; 73:118–119.

29. Boucher LJ, Heupel EM. Prosthetic restoration of a maxilla and associated structures. J Prosthet Dent. 1966; 16:154–168.

30. Javid N. The use of magnets in a maxillofacial prosthesis. J Prosthet Dent. 1971; 25:334–341.

31. Naert IE, Gizani S, Vuylsteke M, van Steenberghe D. A randomised clinical trial on the influence of splinted and unsplinted oral implants in mandibular overdenture therapy. A 3-year report. Clin Oral Investig. 1997; 1:81–88.

32. Burns DR, Unger JW, Elswick RK Jr, Giglio JA. Prospective clinical evaluation of mandibular implant overdentures: Part II--Patient satisfaction and preference. J Prosthet Dent. 1995; 73:364–369.

33. Setz JM, Wright PS, Ferman AM. Effects of attachment type on the mobility of implant-stabilized overdentures--an in vitro study. Int J Prosthodont. 2000; 13:494–499.

34. Thean HP, Khor SK, Loh PL. Viability of magnetic denture retainers: a 3-year case report. Quintessence Int. 2001; 32:517–520.