Biocompatibility and Durability of Diazonium Adhesives on Dental Alloys

Abstract

Purpose A new type of diazonium‐based adhesive has been recently developed by our team to bind dental alloys (Titanium, stainless steel, and cobalt chromium) to dental polymers. Here, we explored the endurance of the resulting adhesive after thermal‐cycling and autoclave aging. Materials and Methods Polished samples of titanium (Ti), stainless steel (SS) and cobalt chromium (Co‐Cr) were coated with a diazonium‐based adhesive. Untreated samples served as controls (n = 12 per each condition). X‐ray photoelectron spectroscopy (XPS) was performed to characterize the elemental compositions of the different surfaces. Biocompatibility of the coated alloys was assessed with human gingival fibroblasts (HGF). Inductively coupled plasma (ICP) and total organic carbon (TOC) analyses were used to quantify the ions and organic matters released from the diazonium coated alloys. Endurance of the adhesives was assessed by exposing the samples to autoclaving and thermal‐cycling. The tensile strength of the poly(methylmethacrylate) (PMMA)‐alloy bond was also tested. Results Results of mechanical testing demonstrated a higher endurance of the coated CoCr, Ti, and SS compared to the uncoated alloys. The human fibroblasts cultured on the substrates remained alive and metabolically active, and the coatings did not release significant amounts of toxic chemicals in solutions. Conclusions The results further support the use of diazonium‐based adhesives as new coupling agents for dental applications.

Biomimetic Strategy to Enhance Epithelial Cell Viability and Spreading on PEEK Implants

“…Here, we used diazonium chemistry as an alternative surface activation step to introduce carboxylic groups on PEEK (and Ti for comparison), followed by EDC/NHS coupling to covalently bind collagen. We selected diazonium chemistry not only because of its simplicity, versatility, and biocompatibility, ,, but also because the stability of the bonds produced with diazonium modification is well-established. , …”

“…76 Here, we used diazonium chemistry as an alternative surface activation step to introduce carboxylic groups on PEEK (and Ti for comparison), followed by EDC/NHS coupling to covalently bind collagen. We selected diazonium chemistry not only because of its simplicity, versatility, and biocompatibility, 49,51,77 but also because the stability of the bonds produced with diazonium modification is well-established. 78,79 While we measured the amount of collagen bound to our substrates using the BCA colorimetric assay, no previous works report this data; thus, to compare the effectiveness of our conjugation strategy to previous ones, we compare N at.…”