Immediate dental implant placement and loading treatment protocol has been investigated with the promising clinical results. However, the use of short implant in this treatment option has not been performed.
 
The purpose of the study was to compare the clinical outcomes and survival rates of immediately-loaded short implants and conventional length dental implants (Pw Plus dental implant system, Thailand) in replacing mandibular molar teeth.

Materials and methods

The clinical study was approved by the Human Experimentation Committee. Fifty implants in 46 patients were included in the study. Twenty five short dental implants (6 mm.) and 25 conventional dental implants (10 mm.) were randomly placed as single tooth replacements in the edentulous molar areas of the mandibles. Provisional, CAD-CAM, ceramic block (Shofu HC) crowns were cemented to the abutments of the implants, and immediately loaded. The clinical parameters, such as insertion torque (IT), resonance frequency analysis (RFA), marginal bone level changes, and complications, were recorded and statistically analysed.

Results

Two short implants and two conventional implants were excluded from the study due to insufficient insertion torque (less than 35 Ncm). Two short implants disintegrated, and one conventional implant failed. The accumulate survival rate of short implants was 91.30%, compared to 95.65% for conventional implants. However, there was no significant difference between the two implant types (P (Fisher’s exact) = 1.00). Only minor complications were found (three provisional crown fractures with short implants and two with conventional implants).The differences in IT among the two implant types were not significant (P =.264). There was no significant difference in ISQ value for short or conventional implants between baseline (short: 73.86 ± 2.38 mm, conventional: 75.05 ± 3.26mm, P=.088) and four months after loading (short: 72.37 ± 1.35 mm, conventional: 72.89 ± 1.87 mm, P=.165). The mean change in marginal bone level four months post-loading was 0.24 ± 0.29 mm for short implants and 0.26 ± 0.29 mm for conventional implants ; there was no statistical difference between the two implant types.

Conclusions

Within the limitations of this study, the findings seem to confirm that the immediate loading of short implants is a viable option, comparable to conventional length implants in terms of implant survival, marginal bone loss and ISQ value.

Comparative study of immediate loading on short dental implants and conventional dental implants in the posterior mandible - A randomized clinical trial four months post-loading.