Short Implants Versus Bone Augmentation and Longer Implants in Atrophic Maxillae. Five Year Post Loading Results of a Randomised Controlled Trial

Abstract

Randomised controlled trial PURPOSE. To evaluate whether short (5 to 8.5 mm) dental implants could be a suitable alternative to longer (at least 11.5 mm long) implants for supporting dental prostheses placed in atrophic fully edentulous maxillae augmented with autogenous bone. MATERIALS AND METHODS.Twenty-eight patients with fully edentulous atrophic maxillae having 5 to 9 mm of residual crestal bone height at least 5 mm thick, as measured on CT scans, were randomised into two groups, either to receive four to eight short (5 to 8.5 mm) implants (15 patients) or autogenous bone from the iliac crest to allow the placement of at least 11.5 mm-long implants (13 patients). Both bone blocks and windows at lifted maxillary sinuses were covered with rigid resorbable barriers. Grafts were left to heal for 4 months before placing implants, which were submerged. After 4 months, provisional reinforced acrylic prostheses or bar-retained overdentures were delivered. Provisional prostheses were replaced after 4 months by definitive screw-retained metal-resin cross-arch restorations. Outcome measures were: augmentation, prosthesis or implant failures, any complications, peri-implant marginal bone level changes, and patient satisfaction. Patients were followed-up until 5 years after loading. RESULTS.All patients could be rehabilitated with implant-supported prostheses, but four patients dropped-out from the augmentation group and three from the short implant group. One bilateral sinus lift procedure failed due to infection, though short implants could be placed. Four implants failed in four patients from the augmentation group versus three short implants in three patients (Fisher's exact test P = 0.6500; difference in proportions = -0.17; 95% CI -0.51 to 0.21). No prosthesis failed. Significantly more complications occurred in augmented patients: 12 complications occurred in nine augmented patients versus one complication in the short implant group (Fisher's exact test P = 0.0003; difference in proportions = -0.82; 95% CI -0.97 to -0.41). Periapical radiographs of only four patients were readable, so no bone level could be measured at 5 years after loading. With the exception of three patients from the augmentation group, who were only partially satisfied with function, all remaining patients were fully satisfied with the treatment (P = 0.0957); all would have the treatment again.CONCLUSIONS. This study showed that in patients with fully edentulous atrophic maxillae, short implants can be a preferable alternative to longer implants placed in bone augmented with autogenous bone, the treatment being less invasive, cheaper, faster and associated with fewer complications. CONFLICT OF INTEREST STATEMENT.MegaGen partially supported this trial and donated the implants and prosthetic components used in the present investigation. However, data property belonged to the authors and MegaGen by no means interfered with the conduct of the trial or the publication of its results.

Immediate Loading of 3 Mm-Diameter Implants as an Alternative to Horizontal Bone Augmentation for Placing 4 Mm-Diameter Implants: One-Year Post-Loading Results From a Multicentre Randomised Controlled Trial

“…It is difficult to compare the results of the present trial with those of similar studies, as these could not be found in the published literature. That being said, our results do show interesting similarities to those of other RCTs investigating vertical atrophy cases, comparing 4-to 6.6-mm short implants versus augmentation procedures to place 10 mm or longer implants [9][10][11][12][13][14] . Such results, obtained in vertically atrophic mandibles, were also summarised in a recent systematic review 15 ; together they suggest that augmentation procedures to create new supporting bone are more technically demanding than placing narrow-diameter or short implants, and are generally associated with higher post-operative morbidity, more complications, longer treatment periods and an increased number of surgeries.…”

Immediate Loading of 3 Mm-Diameter Implants as an Alternative to Horizontal Bone Augmentation for Placing Normal Diameter Implants: Four-Month Post- Loading Results From a Multicentre Randomised Controlled Trial

“…It is difficult to compare the results of the present trial with those from similar trials, as these could not be found in the published literature. That being said, our results do show interesting similarities to those of other RCTs investigating vertical atrophy cases, comparing 4-to 6.6-mm short implants versus augmentation procedures to place 10 mm or longer implants [7][8][9][10][11][12] . Such results, obtained in vertically atrophic mandibles, were also summarised in a recent systematic review 13 ; together they suggest that augmentation procedures to create new supporting bone are more technically demanding than placing small-diameter or short implants, and are generally associated with higher post-operative morbidity, complications, longer treatment periods and an increased number of surgeries.…”

To Splint or Not to Splint Short Dental Implants Under the Same Partial Fixed Prosthesis? One-Year Post-Loading Data From a Multicentre Randomised Controlled Trial

“…Short dental implants (4 to 8 mm long) 1 have been reported as an appealing and less invasive alternative to bone augmentation procedures for placing longer implants, with both groups displaying similar results up to 11 years after loading [2][3][4][5][6][7][8][9][10][11] . One of the issues often debated is whether it is better or not to join two or more short implants under the same prosthesis to decrease the potential risks of failures or mechanical complications such as screw loosening.…”