Primary stability in a large sample of implants – Distribution and correlation with bone density

Background

Primary stability has become an important topic since immediate loading protocols were extensively used. Modern dental implants easily achieve good primary stability thanks to the geometry and dedicated insertion protocols. Nevertheless, few studies showed data about primary stability from large samples of implants.

Aim/Hypothesis

The aim of the present study is to report primary stability data and its correlation with bone density from a sample of 1,846 implants.

Material and Methods

Patients were considered suitable for the study if they needed the insertion of single or multiple implants. During surgery peak insertion torque (IT) and RFA values were documented for each implant. Furthermore, bone density was determined before surgery by means of periapical radiographs and was confirmed by the evaluation of the drilling resistance during implant bed preparation.

Results

Of 03 consecutive patients were included in the study. A total of 1,846 of implants were inserted. The implants inserted in D1 bone were 308 and they presented a mean IT of 51.5 + 18.25 Ncm and a mean RFA of 77.96 + 7.3 ISQ. The implants in D2 bone were 776 (mean IT 42.9 + 19.18 Ncm and mean RFA 77.26 + 8.44 ISQ). The implants in D3 bone were 681 (mean IT 34.27 + 17.05 Ncm and mean RFA 77.93 + 47.17 ISQ). The implants in D4 bone were 81 (mean IT 22.8 + 16.61 Ncm and mean RFA 72.84 + 10.07 ISQ). The Pearson correlation between IT and bone density was 0.3643 (P < 0.0001) whereas between RFA and bone density was 0.0495 (P = 0.03).

Conclusion and Clinical Implications

The results show that the implants studied presented an overall good primary stability when inserted in the different bone density situations+ furthermore, data showed a positive correlation between bone density and primary stability parameters.