Influence of anaerobic adhesive on the resonance frequency analysis measured in abutments with external hexagon and conical connections: an in vitro study

To evaluate whether the application of an anaerobic adhesive (AA) to the abutment screws interferes with the implant stability quotient (ISQ) values in abutments with external hexagon (EHC) and conical connections (CC).

20 implants 4.0 mm x 10 mm were used, with similar formats, 10 with EHC and 10 with CC, inserted by the same operator into fresh bovine ribs. The abutment was then screwed with a high precision digital torque meter, and resonance frequency was measured. The abutments were then unscrewed, a drop of Loctite 242 adhesive was applied along the entire length of the thread, the abutments were screwed again (Groups EHC-AA and CC-AA). The ISQ was registered immediately, 24 h, and 72 h after installation. Data were analyzed using descriptive statistics and comparison tests (p < 0.05).

ISQ values measured in abutments without AA were significantly higher than those measured after applying the adhesive, for EHC and CC. The one-way repeated measures ANOVA showed that, in the intragroup analysis, there was no statistically significant difference in the ISQ, comparing the three measurement moments after applying the adhesive, irrespective of connection system (CC: F = 0.191, p = 0.827; EHC: F = 0.323, p = 727), which suggests that the adhesive curing does not affect the ISQ.

The use of an AA on abutment screws had a significant effect on RFA measurements, for EHC and CC. The curing time of the AA did not affect the ISQ values measured in the abutments.

The ISQ values cannot be compared in situations with and without AA.