Recommended by PD Dr. med. Dr. med. dent. David Schneider
Insights from this study for clinical practice
Rough implant surfaces should be preferred over machined implant surfaces.
Dental practitioners know the importance of osseointegration in the success of dental implants, yet how many fully appreciate the process at the cellular level? Although having been published 20 years ago, this paper by Abrahamsson et al. remains a valuable resource for those interested in the details and background behind modern dental practices.
The researchers used devices with geometry corresponding to a solid screw implant, with either a rough, sandblasted and acid-etched (SLA) or a turned (T), machined surface. These were implanted into 20 dogs (160 devices), and biopsies were obtained at various time points to evaluate the healing process from 2 hours to 12 weeks post-surgery.
The paper leads the reader through the main features at each time point, from the erythrocytes embedded in a fibrin network at 2 hours post-surgery, to bone remodeling at 12 weeks. The histology of the wound chamber is both clearly described and visualized in numerous images, giving a real sense of the small details behind this important process.
PD Dr. med. Dr. med. dent. David Schneider
The paper shows very nicely the processes of bone growth on implants with the help of histological images.
As well as describing the minutiae of bone formation, the authors compare and contrast the observations of the SLA and T devices. The wound chambers of both devices were initially filled with a blood clot, and also showed early proliferation of vascular structures and migration of fibroblast-like mesenchymal cells. The resulting woven bone formation occurred earlier and was more pronounced in the SLA versus T devices, at 1 and 2 weeks post-surgery. Similarly, osteoblasts were more numerous with the SLA versus T devices, and remodeling from primary bone spongiosa to lamella and/or parallel-fibered bone was faster with SLA than T devices. By 4 weeks, the lamellar bone volume was higher with T than SLA devices, and at 6, 8, and 12 weeks there was more mineralized tissue with T than SLA devices.
The authors also measured features such as the bone-to-implant contact, which was significantly higher with the SLA versus T devices at all time points from 1 week onwards. Therefore, despite greater proportions of mineralized bone with T than SLA, the authors considered osseointegration more prominent at SLA than T surfaces due to the significantly greater contact area between newly formed bone and titanium walls of the device.
This 20-year-old paper has stood the test of time and contains valuable insights for today’s dental practitioners. The evidence behind the use of rough versus machined implant surfaces provides important context for decision-making, and also allows dentists to explain implant features to interested patients.
