Can Abutment with Novel Superlattice CrN/NbN Coatings Influence Peri-Implant Tissue Health and Implant Survival Rate Compared to Machined Abutment? 6-Month Results from a Multi-Center Split-Mouth Randomized Control Trial

Background: The aim of the present multi-center split-mouth randomized control trial was to investigate the effect on peri-implant tissue of abutment with chromium nitride/ niobium nitride (CrN/NbN) coatings (superlattice) compared to traditional machined surface. Methods: Two adjacent posterior implants were inserted in 20 patients. A machined abutment was randomly screwed on either the mesial or distal implant, while a superlattice abutment was screwed on the other one. Implant survival rate, peri-implant probing depth (PPD), plaque index (PI), and bleeding index (BI) were collected 6 months after surgery, while marginal bone loss (MBL) was evaluated at T0 and T6.; Results: Implant survival rate was 97.7%. A total MBL of 0.77 +/- 0.50 mm was recorded for superlattice abutments, while a mean MBL of 0.79 +/- 0.40 mm was recorded for the abutment with machined surface. A mean PPD of 1.3 +/- 0.23 mm was recorded for the superlattice Group, and a mean PPD of 1.31 +/- 0.3 was recorded for the machined surface Group. PI was of 0.55 +/- 0.51 for superlattice Group and 0.57 +/- 0.50 for machined Group, while BI was of 0.47 +/- 0.49 for superlattice Group and of 0.46 +/- 0.40 for the machined one. No statistically significant difference was highlighted between the two Groups (p > 0.05). Conclusions: After a 6-month observational period, no statistically significant differences were highlighted between superlattice abutment and traditional machined abutment. Further in vitro studies as well as clinical research with longer follow-ups are required to better investigate the surface properties of the novel abutments' superlattice coating and its effect on the oral tissues.

Automated summary

The aim of this study was to compare the effect of abutments with chromium nitride/niobium nitride coatings (superlattice) to traditional machined surface on peri-implant tissue. The results showed no statistically significant differences between the superlattice abutment and the machined abutment after a 6-month observational period. Further research and clinical studies are needed to investigate the surface properties of the novel abutments' superlattice coating and its effect on oral tissues.