Safety and efficacy of a biomimetic monolayer of permanently bound multiphosphonic acid molecules on dental implants: 3 years post-loading results from a pilot quadruple-blinded randomised controlled trial.

PURPOSE: To evaluate the safety and clinical efficacy of a novel surface treatment (SurfLink, Nano Bridging Molecules, Gland, Switzerland) on titanium dental implants. SurfLink consists of a monolayer of permanently bound multiphosphonic acid molecules, which mimics the surface of naturally occurring hydroxyapatite. MATERIALS AND METHODS: Twenty-three patients requiring at least two single dental implants had their sites randomised according to a split-mouth design to receive one titanium grade 4 implant treated with SurfLink and one untreated control implant. Additional SurfLink-treated implants were placed if needed. Implants were submerged for 3 months in mandibles and 6 months in maxillae, then loaded with definitive metal-ceramic crowns and followed for 3 years after loading. Outcome measures were crown/implant failures, any complication, radiographic peri-implant marginal bone level changes and marginal bleeding. RESULTS: Three patients dropped out but all remaining patients were followed up to 3-years post-loading. No implant failed. Complications were reported for three patients, affecting both types of implant in two patients and only SurfLink implant in one patient. No differences for complications between the two implant types was observed (McNemar test, P = 1, difference in proportions = -0.04, 95% CI: -0.22 to 0.14). No bleeding was observed when a periodontal probe was run in the peri-implant soft tissues around any of the implants, with the exception of three implants affected by peri-implantitis. There were no statistically significant differences in marginal bone level changes between the two groups (at 3 years post-loading P = 0.86, mean difference = -0.05; SD = 1.15; 95% CI: -0.56 to 0.47). CONCLUSIONS: Medium-term data (3-years post-loading) of implants with a biomimetic monolayer of permanently bound multiphosphonic acid molecules (SurfLink surface treatment) presented no safety issues. Clinical healing in both control and SurfLink-treated implant groups was uneventful and did not differ significantly. More challenging clinical situations need to be investigated to evaluate the real effectiveness of this surface treatment. Conflict-of-interest statement: Marco Esposito and Ivan Dojcinovic declare that they have no conflict of interest, and they acted as consultants for Nano Bridging Molecules (NBM). Sabrina Buchini, Péter Péchy and Björn-Owe Aronsson are employed at NBM. NBM, the manufacturer of the SurfLink surface treatment, supported and carefully monitored this trial without interfering with the presentation of its results.

A novel multi-phosphonate surface treatment of titanium dental implants: a study in sheep.

The aim of the present study was to evaluate a new multi-phosphonate surface treatment (SurfLink®) in an unloaded sheep model. Treated implants were compared to control implants in terms of bone to implant contact (BIC), bone formation, and biomechanical stability. The study used two types of implants (rough or machined surface finish) each with either the multi-phosphonate Wet or Dry treatment or no treatment (control) for a total of six groups. Animals were sacrificed after 2, 8, and 52 weeks. No adverse events were observed at any time point. At two weeks, removal torque showed significantly higher values for the multi-phosphonate treated rough surface (+32% and +29%, Dry and Wet, respectively) compared to rough control. At 52 weeks, a significantly higher removal torque was observed for the multi-phosphonate treated machined surfaces (+37% and 23%, Dry and Wet, respectively). The multi-phosphonate treated groups showed a positive tendency for higher BIC with time and increased new-old bone ratio at eight weeks. SEM images revealed greater amounts of organic materials on the multi-phosphonate treated compared to control implants, with the bone fracture (from the torque test) appearing within the bone rather than at the bone to implant interface as it occurred for control implants.

Safety and efficacy of a biomimetic monolayer of permanently bound multi-phosphonic acid molecules on dental implants: 1 year post-loading results from a pilot quadruple-blinded randomised controlled trial.

PURPOSE: To evaluate the safety and clinical efficacy of a novel surface treatment (SurfLink®, Nano Bridging Molecules, Gland, Switzerland) on titanium dental implants. SurfLink consists of a monolayer of permanently bound multi-phosphonic acid molecules, which mimics the surface of naturally occurring hydroxyapatite. MATERIALS AND METHODS: Twenty-three patients requiring at least two single dental implants had their sites randomised according to a split-mouth design to receive one titanium grade 4 implant treated with SurfLink and one untreated control implant. Additional SurfLink-treated implants were placed if needed. Implants were submerged for 3 months in mandibles and 6 months in maxillae, were loaded with definitive metal-ceramic crowns, and followed up for 1 year after loading. Outcome measures were crown/implant failures, any complication, radiographic peri-implant marginal bone level changes and marginal bleeding. RESULTS: One patient dropped out after abutment connection. All remaining patients were followed up to 1 year post-loading. No implant failed and only 1 postoperative complication (pain) occurred, but it may not have been related to the implant treatment. No bleeding was observed when a periodontal probe was used to examine the peri-implant soft tissues around the implants. There were no statistically significant differences in marginal bone level changes between the two groups (P = 0.057, mean difference = -0.27, SE = 0.13; 95% CI -0.55 to 0.01). CONCLUSIONS: Preliminary short-term data (1 year post-loading) of implants with a biomimetic monolayer of permanently bound multi-phosphonic acid molecules (SurfLink surface treatment) presented no safety issues. Clinical healing in both the control and SurfLink-treated implant group was uneventful and did not differ significantly between groups. More challenging clinical situations need to be investigated to evaluate the real effectiveness of this surface treatment.

Osteoblast culture on polished titanium disks modified with phosphonic acids.

Titanium is widely used in dental implants due to its suitable physical properties and its good biocompatibility. However, it is integrated into bone only passively, and the resulting fixation in the bone, which is necessary for the function, is mainly mechanical in nature. With the objective of increasing the chemical interaction between the implant and the bone tissue, several phosphonic acids were synthesized and grafted onto titanium disks. Here we report on the proliferation, differentiation, and protein production of rat osteoblastic cells (CRP10/30) on phosphonic-acid-modified titanium surfaces studied in vitro. No statistical differences were found in osteoblast proliferation among the phosphonic-acid-modified titanium, unmodified titanium, and tissue culture plastic (used as a positive control), indicating that the phosphonic acids used were not cytotoxic to the osteoblasts used. For all surfaces (modified or not), the alkaline phosphatase activity was at least as good as it was on tissue culture plastic. However, the total amount of protein, and especially the collagen type I synthesis, was sensitive to surface modification. On titanium modified with ethane-1,1,2-triphosphonic acid, the total amount of synthesized protein was significantly higher than it was on unmodified titanium surfaces. A significant increase (up to 16%) of collagen type I production was observed on titanium surfaces modified with this acid or with methylenediphosphonic acid compared to unmodified titanium surfaces.