Various Attachments for Implant Overdentures: Comparison
View Latest Version
Please note this is a comparison between Version 2 by Jessie Wu and Version 1 by Borvornwut Buranawat.

This study presents an overview of the biomechanical and biomolecular aspects of various attachments for implant overdenture. We focused on the following topics: attachment systems, retention of various attachments, stress distribution with different attachments, the design and fabrication of attachments, digital techniques in overdenture attachments, and the effects of attachments in peri-implant health. We found that plastic resin is commonly used for ball and bar attachments, whereas nylon resin is commonly used in locator attachments. The locator system offers a valuable attachment option for implant-retained overdenture. Attachment retention reduces while lateral force increases with implant inclination in overdenture. The higher the retention of an overdenture attachment, the higher the transferred stresses. Additionally, clip loading produces more stress in implants and precision elements than bar-retained dentures. As such, we conclude that the ball and locator systems the best overdenture systems due to their superior tissue response, survival rate, and patient satisfaction.

  • overdenture
  • attachments

1. Introduction

At present, implants are widely used to replace missing teeth or retention/support dentures [1]. The use of implant-retained overdentures in the maxilla and mandible is a successful option to the fixed implant prostheses. The types of attachments available in the market include non-splinted attachments (ball, magnet, locator, and double crown attachment) and splinted attachments (bar and clip attachment) [2,3,4][2][3][4]. Figure 1 shows the ball attachment to retain overdenture [3].
Polymers 13 03248 g001 550
Figure 1. Ball attachment to retain overdenture (A) and overdenture (tissue surface) (B) [3].
The locator attachment system is a suitable choice for implant-retained or implant-supported overdenture [5]. There has been considerable development in attachments for implant overdenture; however, there is a need for updated information regarding implant overdenture attachments is lacking. As such, this review presents an overview of various attachments’ biomechanical and biomolecular aspects, with focus on attachment systems, the retention of various attachments, stress distribution with different attachments, the design and fabrication of attachments, digital techniques in overdenture attachments, and the effects of attachments in peri-implant health. After assessing the available articles on overdenture attachments from January 1980 to August 2021 using the PubMed/MEDLINE, ScienceDirect, and Web of Science resources, relevant studies on overdenture attachments were included in this study.

2. Effects of Attachment Types on Implant Overdenture

Attachments vary in shape and include ball, bar, locator, magnet, and locator types. Stud attachments are either rigid (ball) or resilient (magnet, locator, and double crown attachment). Table 1 presents an overview of the various attachments in overdenture.
Table 1. Advantages and disadvantages of the various attachments in overdenture.
Attachment Type Advantages Disadvantages Reference
Ball attachment

(O-ring attachment) Simple manufacturing process, the provision of a wide range of movement, cost-effectiveness, ease of use, good retention, easy hygiene maintenance, and high patient satisfaction. The abutment requires implants to be parallelly placed, and the loss of parallelism may cause difficulty while inserting and removing the prosthesis or during the fracturing of the abutment. The O-ring needs to be regularly changed because it is subject to wear. [10,11][6][7]
Bar attachment Provides retention, implant splinting, and wide-ranging load distribution that results in a movement reduction of the implants. Technique-sensitive, expensive, and present difficult hygiene maintenance under the bars, leading to mucosal swelling or gingival hyperplasia. Bars are not indicated in a V-shaped ridge because this leads to the infringement of tongue space. [12,13][8][9]
Locators Locators are popular attachments for implant-retained or implant-supported overdenture because of their low level of thickness (2.5 mm height) and ability to self-align, which can correct up to 40° of implant angulations. They can be used in narrow inter-arch space. Locators offer excellent retention and stability, and they allow for easy hygiene maintenance. The telescopic attachment, which offers a self-seating mechanism, is suitable for patients with reduced manual dexterity, such as those with Parkinson’s disease. Periodic replacement of the male nylon component is required. Some prosthetic complications such as locator attachments, periodic repair, and higher maintenance double-crown locator attachments require sufficient inter-arch space and the metal display of attachments. [8,14,15,16,17][10][11][12][13][14]
Magnetic attachments Magnetic attachments reduce the transfer of horizontal stress to the implants and bone during the insertion and removal of the denture. These are low-profile attachments; however, corrosion and loss of magnetism are significant complications associated with their usage. [18,19,20,21][15][16][17][18]
The ball attachment (O-ring attachment) is the most commonly used overdentures and contains a ball shape for retention. Its advantages include a simple manufacturing process, the provision of a wide range of movement, cost-effectiveness, ease of use and maintenance, the provision of good retention, hygiene maintenance, and good patient satisfaction [10,11][6][7]. However, the ball attachment abutment requires implants to be parallelly placed, and the loss of parallelism may cause difficulty while inserting and removing the prosthesis or during the fracturing of the abutment [10][6]. Additionally, the O-ring needs to be regularly changed because it is subject to wear [10][6].
A bar attachment offers retention, the splinting of implants, and the distribution of load, resulting in reduced implant stress, which is critical for the immediate loading protocol [12][8]. The restoration of moderately to severely atrophic maxilla remains a challenge. In such cases, CAD/CAM titanium bar-supported overdenture can be an important treatment choice for an edentulous patient’s rehabilitation (Figure 2) [22][19]. Figure 2 shows a maxillary overdenture supported by four or six implants for the minimally invasive rehabilitation of atrophic maxillae. The disadvantages of bar attachments include technique-sensitivity, high costs, and difficult hygiene maintenance under the bars that leads to mucosal swelling or gingival hyperplasia [12,13][8][9]. Furthermore, bars are not indicated in a V-shaped ridge because this causes the infringement of tongue space [23][20].
Polymers 13 03248 g002 550
Figure 2. CAD/CAM titanium-bar-supported maxillary overdenture Pretreatment radiograph (A), 4 implants placed in maxillary arch (B), CAD design of the titanium bar (C), titanium bar inserted in the mouth (D), occlusal view of titanium bar (E), definitive prosthesis (F) [22][19].
Locators are currently popular attachments because of their low level of thickness (2.5 mm height) [16][13] and ability to self-align, which can correct up to 40° of implant angulations [16][13]. They can be used in narrow inter-arch space and prevent the fracture of the denture base [17][14]. Locators offer excellent retention and stability, and they allow for easy hygiene maintenance. The telescopic attachment, which offers a self-seating mechanism, is appropriate for patients with reduced manual dexterity, such as those with Parkinson’s disease. However, the periodic replacement of the male nylon part is required [14][11]. Some prosthetic complications have been noted in locator attachments. One study reported 34 prosthetic complications and a locator housing requiring 16 replacements [8,15][10][12]. To avoid complications, locator attachments require periodic repair and higher maintenance [24][21]. Recently, researchers invented a double-crown attachment option for locator attachments have that connects dentures to prepared teeth [25][22]. However, the disadvantages of locators include the need for sufficient inter-arch space and the metal display of attachments [26][23]. The locator attachment system is a suitable choice for implant-retained or implant-supported overdenture [5].
Magnetic attachments have a long history (>60 years) of use in denture retention [27][24]. They reduce the transfer of horizontal stress to the implants and the bone during the insertion and removal of the denture [18][15]. They are low-profile attachments [19][16], and the corrosion and loss of magnetism are significant complications associated with their usage [20,21][17][18].
Overdenture attachments present very high survival rates. One study reported survival rates ranging from 96% to 97% for bar attachments, 96% to 100% for ball attachments, 90% to 92% for magnets, and 97% for locators with a mean follow-up period of 3 years [24][21]. Other studies have reported a 94% five-year survival rate for the bar attachment [28][25]; 89% and 93% survival rates for the bar and locator, respectively; [29][26], and 98% and 97% survival rates for the bar and the locator, respectively [30][27].

References

  1. Vi, S.; Pham, D.; Du, Y.Y.M.; Arora, H.; Tadakamadla, S.K. Mini-implant-retained overdentures for the rehabilitation of completely edentulous maxillae: A systematic review and meta-analysis. Int. J. Environ. Res. Public Health 2021, 18, 4377.
  2. Aldhohrah, T.; Mashrah, M.A.; Wang, Y. Effect of 2-implant mandibular overdenture with different attachments and loading protocols on peri-implant health and prosthetic complications: A systematic review and network meta-analysis. J. Prosthet. Dent. 2021, in press.
  3. Ceraulo, S.; Leonida, A.; Lauritano, D.; Baldoni, A.; Longoni, S.; Baldoni, M.; Caccianiga, G. Proposal for a clinical approach to geriatric patients with anchor need on implant for removable denture: New technique. Prosthesis 2020, 2, 185–195.
  4. Amornvit, P.; Rokaya, D.; Bajracharya, S.; Keawcharoen, K.; Supavanich, W. Management of obstructive sleep apnea with implant retained mandibular advancement device. World J. Dent. 2014, 5, 184–189.
  5. Daou, E.E. Stud attachments for the mandibular implant-retained overdentures: Prosthetic complications. A literature review. Saudi Dent. J. 2013, 25, 53–60.
  6. Winkler, S.; Piermatti, J.; Rothman, A.; Siamos, G. An overview of the o-ring implant overdenture attachment: Clinical reports. Oral Implant. 2002, 28, 82–86.
  7. Sadowsky, S.J. Mandibular implant-retained overdentures: A literature review. J. Prosthet. Dent. 2001, 86, 468–473.
  8. Cakarer, S.; Can, T.; Yaltirik, M.; Keskin, C. Complications associated with the ball, bar and locator attachments for implant-supported overdentures. Med. Oral Patol. Oral Cir. Bucal 2011, 16, e953–e959.
  9. Payne, A.G.; Solomons, Y.F.; Tawse-Smith, A.; Lownie, J.F. Inter-abutment and peri-abutment mucosal enlargement with mandibular implant overdentures. Clin. Oral Implant. Res. 2001, 12, 179–187.
  10. Alsabeeha, N.H.; Swain, M.V.; Payne, A.G. Clinical performance and material properties of single-implant overdenture attachment systems. Int. J. Prosthodont. 2011, 24, 247–254.
  11. Alsabeeha, N.H.; Payne, A.G.; De Silva, R.K.; Thomson, W.M. Mandibular single-implant overdentures: Preliminary results of a randomised-control trial on early loading with different implant diameters and attachment systems. Clin. Oral Implant. Res. 2011, 22, 330–337.
  12. Kleis, W.K.; Kämmerer, P.W.; Hartmann, S.; Al-Nawas, B.; Wagner, W. A comparison of three different attachment systems for mandibular two-implant overdentures: One-year report. Clin. Implant Dent. Relat. Res. 2010, 12, 209–218.
  13. Vasant, R.; Vasant, M.K. Retention systems for implant-retained overdentures. Dent. Update 2013, 40, 28–31.
  14. ELsyad, M.A.; Fathe Mahanna, F.; Samir Khirallah, A.; Ali Habib, A. Clinical denture base deformation with different attachments used to stabilize implant overdentures: A crossover study. Clin. Oral Implant. Res. 2020, 31, 162–172.
  15. Chung, K.H.; Chung, C.Y.; Cagna, D.R.; Cronin, R.J., Jr. Retention characteristics of attachment systems for implant overdentures. J. Prosthodont.: Off. J. Am. Coll. Prosthodont. 2004, 13, 221–226.
  16. Naert, I.; Gizani, S.; Vuylsteke, M.; Van Steenberghe, D. A 5-year prospective randomized clinical trial on the influence of splinted and unsplinted oral implants retaining a mandibular overdenture: Prosthetic aspects and patient satisfaction. J. Oral Rehabil. 1999, 26, 195–202.
  17. Boeckler, A.F.; Ehring, C.; Morton, D.; Geis-Gerstorfer, J.; Setz, J.M. Corrosion of dental magnet attachments for removable prostheses on teeth and implants. J. Prosthodont.: Off. J. Am. Coll. Prosthodont. 2009, 18, 301–308.
  18. Laverty, D.P.; Green, D.; Marrison, D.; Addy, L.; Thomas, M.B. Implant retention systems for implant-retained overdentures. Br. Dent. J. 2017, 222, 347–359.
  19. Tallarico, M.; Cervino, G.; Scrascia, R.; Uccioli, U.; Lumbau, A.; Meloni, S.M. Minimally invasive treatment of edentulous maxillae with overdenture fully supported by a cad/cam titanium bar with a low-profile attachment screwed on four or six implants: A case series. Prosthesis 2020, 2, 53–64.
  20. Karabuda, C.; Tosun, T.; Ermis, E.; Ozdemir, T. Comparison of 2 retentive systems for implant-supported overdentures: Soft tissue management and evaluation of patient satisfaction. J. Periodontol. 2002, 73, 1067–1070.
  21. Chaware, S.H.; Thakkar, S.T. A systematic review and meta-analysis of the attachments used in implant-supported overdentures. J. Indian Prosthodont. Soc. 2020, 20, 255–268.
  22. Langer, A. Telescope retainers for removable partial dentures. J. Prosthet. Dent. 1981, 45, 37–43.
  23. Langer, A. Telescope retainers and their clinical application. J. Prosthet. Dent. 1980, 44, 516–522.
  24. Gonda, T.; Maeda, Y. Why are magnetic attachments popular in japan and other asian countries? Jpn. Dent. Sci. Rev. 2011, 47, 124–130.
  25. Mericske-Stern, R.; Oetterli, M.; Kiener, P.; Mericske, E. A follow-up study of maxillary implants supporting an overdenture: Clinical and radiographic results. Int. J. Oral Maxillofac. Implant. 2002, 17, 678–686.
  26. Kappel, S.; Giannakopoulos, N.N.; Eberhard, L.; Rammelsberg, P.; Eiffler, C. Immediate loading of dental implants in edentulous mandibles by use of locator ® attachments or dolder ® bars: Two-year results from a prospective randomized clinical study. Clin. Implant. Dent. Relat. Res. 2016, 18, 752–761.
  27. Boven, G.C.; Meijer, H.J.A.; Vissink, A.; Raghoebar, G.M. Maxillary implant overdentures retained by use of bars or locator attachments: 1-year findings from a randomized controlled trial. J. Prosthodont. Res. 2020, 64, 26–33.
More
© Text is available under the terms and conditions of the Creative Commons Attribution (CC BY) license (http://creativecommons.org/licenses/by/4.0/)
ScholarVision Creations
Feedback