Effects of Implant/Tissue Support of Dentures on Masticatory Performance

Objectives: Improvements in masticatory performance have been found with the provision of a mandibular overdenture (IOD) and conventional maxillary denture (CD) in patients with resorbed ridges or adaptation difficulties, but only to the level of the average conventional denture wearer with adequate ridges. The purpose of this study was to determine if increased implant-support of maxillary and mandibular prostheses significantly improves masticatory function compared to conventional dentures.

Methods: A total of 16 edentulous male participants with complete conventional dentures received maxillary and mandibular overdentures retained by two osseointe¬grated anterior implants splinted with a Hadar bar, followed by a mandibular fixed bridge supported by 5-6 implants and an implant-supported (6 implants) maxillary overdenture (ISD). Masticatory performance tests were completed with the original CDs, four months after delivery of the IODs and four months after delivery of the implant-supported dentures. Statistical comparisons were made for the change in performance between denture conditions with ANOVAs for each of two foods, peanuts and carrots.

Results: Mean performances with CDs for peanuts (33.5+/-9.1) and carrots (56.2+/-25.1) were comparable to previous reports for average denture wearers. Significant improvement (mean increase = 12.1+/-11.4; p<0.001) in masticatory performance with peanuts to 45.0+/-14.9 was seen following treatment with IODs. Mean performance with carrots improved by 4.9+/-25.1 to 60.4+/-20.5 (p>0.05). Additional gains were seen in masticatory performance with the ISDs, with the peanut performance increasing by 2.1+/-13.8 (>0.05) and carrot performance increasing 21.5+/-19.5 (p<0.01) compared to the IODs.

Conclusions: Both overdentures and fully implant-supported dentures produced significant improvement in masticatory performance compared to the original CDs. This improvement in performance was greater than seen in previous samples of average denture wearers treated with implant overdentures in the mandible only. Fully implant supported dentures offer additional functional improvement compared to implant overdentures.

Supported by DVA Medical Research Service.