A Novel Method to Evaluate the Neurocompatibility of Dental Implants

Abstract

To evaluate the neurocompatibility of different types of dental implant surface treatments using the P19 neural cell line. P19 cells were plated and supplemented with retinoic acid to grow as aggregates for 4 days. Twenty dental implants were selected from four different implant systems with five different surface treatments. The implants were divided into four groups (n=5), placed inside medical rings, and fixed by injection of warm gutta-percha using a thermoplastic injection technique. Implant molds were placed inside graded culture dishes, and culture medium containing P19 neural cells were plated on the dishes for 4 days. After 24 hours, the surfaces of the implant molds were covered with self-curing resin to make a replica of each mold surface. Replicas were assessed under a scanning electron microscope, and the number of cells and the total cells covering the areas were evaluated. Data were analyzed by a post hoc Tukey test. There were significant differences in P19 cell counts between all modified and electropolished surfaces. The highest P19 cell counts were shown on OsseoSpeed and Laser-Lok surfaces. The lowest counts were shown on the Nanotite surface at the collar. OsseoSpeed and Laser-Lok surfaces showed higher counts at the collar than on the body; the opposite was seen for SLActive and Nanotite surfaces. Cell-covered areas on Laser-Lok surfaces showed significantly higher values than the resorbable blasted media (RBM)-treated surfaces, while it was not significantly different from the OsseoSpeed surface of collar regions. SLActive collar regions showed larger cell-covered areas than the SLActive body surfaces, but this was not significant. All test surface treatments in this study showed better neurocompatibility than control group surfaces. The Laser-Lok, RBM, and OsseoSpeed surfaces were superior to the Nanotite and SLActive surfaces in terms of neurocompatibility.