Maxillary implant overdentures: Why are they controversial? A Review

J Dudley, School of Dentistry, Faculty of Health Sciences, The University of Adelaide, South Australia

Context

Mandibular implant overdentures have established and predictable benefits over traditional mucosa-borne mandibular dentures and now form part of mainstream dentistry. Maxillary implant overdentures present a number of different challenges.

Purpose of the Review

This selective review highlights the paucity of evidence and inconsistent findings in the maxillary implant overdenture literature.

Literature Review Highlights

Implant Survival

The provision of maxillary implant overdenture treatment requires careful assessment of a myriad of factors, and has been described as challenging and presenting inherent problems. (1,2) 

Mandibular Overdentures

In contrast to maxillary implant overdentures, mandibular implant overdentures have been widely researched and more commonly reported in the literature. (3, 4, 5) 

Number of Implants

Some sources have recommended a minimum of four implants to support maxillary overdentures. (6, 7, 8) 

Splinted Implants

It has been proposed that implants supporting overdentures should be splinted to gain mechanical advantage, distribute forces across multiple implants, provide cross-arch stabilization and avoid potential overloading of single implants. (6, 3, 9)      

Attachments

There are many different types of implant attachment systems available in the marketplace today, each with their proposed advantages. Although there are established differences in the retentive strengths of various designs, there is a lack of conclusive clinical evidence that demonstrates the superiority of one particular attachment system over another. (10, 7, 9)

Patient Satisfaction

In contrast to mandibular implant overdentures, there is limited literature available that has evaluated patient satisfaction with maxillary implant overdentures. (10, 11, 12)   

Maintenance 

High prosthetic maintenance requirements have been reported in maxillary implant overdentures but have been difficult to standardize. (10, 7, 4)

Evidence

The prosthodontic literature in general contains a lack of scientific evidence supporting clinical procedures and concepts. (13, 14) 

Conclusions

Despite the lack of consensus guidelines for a specific treatment modality, the limited evidence available tends to support maxillary implant overdentures as a viable treatment in appropriately selected, planned and executed cases.

References

1. Mericske-Stern R. Treatment outcomes with implant-supported overdentures: clinical considerations. J Prosthet Dent 1998; 79:66–73.
2. Mericske-Stern RD, Taylor TD, Belser U. Management of the edentulous patient. Clin Oral Implants Res 2000;11:108–125.
3. Stoumpis C, Kohal J. To splint or not to splint oral implants in the implant-supported overdenture therapy? A systematic literature review. J Oral Rehabil 2011;38:857–869.
4. Osman RB, Payne A, Ma S. Prosthodontic maintenance of maxillary implant overdentures: a systematic literature review. Int J Prosthodont 2012;25:381–391.
5. Feine JS, Carlsson GE, Awad MA, et al. The McGill Consensus Statement on Overdentures. Eur J Prosthodont Restor Dent 2002;10:95–96.
6. Slot W, Raghoebar GM, Vissink A, Huddleston Slater JJ, Meijer HJA. A systematic review of implant-supported maxillary overdentures after a mean observation period of at least 1 year. J Clin Periodontol 2010;37:98–110.
7. Sadowsky SJ. Treatment considerations for maxillary implant overdentures: a systematic review. J Prosthet Dent 2007; 97:340–348.
8. Keiner P, Oetterli M, Mericske E, Mericske-Stern R. Effectiveness of maxillary overdentures supported by implants: maintenance and prosthetic complications. Int J Prosthodont 2001; 14:133–140.
9. Trakas T, Michalakis K, Kang K, Hirayama H. Attachment systems for implant retained overdentures: a literature review. Implant Dent 2006;15:24–34.
10. Andreiotelli M, Strub J-R. Prosthodontic complications with implant overdentures: a systematic literature review. Int J Prosthodont 2010;23:195–203.
11. The glossary of prosthodontic terms. J Prosthet Dent 2005; 94:10–92.
12. Zitzmann N, Marinello CP. Treatment outcomes of fixed or removable implant-supported prostheses in the edentulous maxilla. Part 1: Patients’ assessments. J Prosthet Dent 2000; 83:424–433.
13. Carlsson G. Critical review of some dogmas in prosthodontics. J Prosthodont Res 2009;53:3–10.
14. 32. Harwood CL. The evidence base for current practices in prosthodontics. Eur J Prosthodont Restor Dent 2008;16: 24–34.