The Effect of Resin Bonding on Long-Term Success of High-Strength Ceramics

Abstract

Digital manufacturing, all-ceramics, and adhesive dentistry are currently the trendiest topics in clinical restorative dentistry. Tooth- and implant-supported fixed restorations from computer-aided design (CAD)/computer-aided manufacturing (CAM)-fabricated high-strength ceramics-namely, alumina and zirconia-are widely accepted as reliable alternatives to traditional metal-ceramic restorations. Most recent developments have focused on high-translucent monolithic full-contour zirconia restorations, which have become extremely popular in a short period of time, due to physical strength, CAD/CAM fabrication, and low cost. However, questions about proper resin bonding protocols have emerged, as they are critical for clinical success of brittle ceramics and treatment options that rely on adhesive bonds, specifically resin-bonded fixed dental prostheses or partial-coverage restorations such as inlays/onlays and veneers. Resin bonding has long been the gold standard for retention and reinforcement of low- to medium-strength silica-based ceramics but requires multiple pretreatment steps of the bonding surfaces, increasing complexity, and technique sensitivity compared to conventional cementation. Here, we critically review and discuss the evidence on resin bonding related to long-term clinical outcomes of tooth- and implant-supported high-strength ceramic restorations. Based on a targeted literature search, clinical long-term studies indicate that porcelain-veneered alumina or zirconia full-coverage crowns and fixed dental prostheses have high long-term survival rates when inserted with conventional cements. However, most of the selected studies recommend resin bonding and suggest even greater success with composite resins or self-adhesive resin cements, especially for implant-supported restorations. High-strength ceramic resin-bonded fixed dental prostheses have high long-term clinical success rates, especially when designed as a cantilever with only 1 retainer. Proper pretreatment of the bonding surfaces and application of primers or composite resins that contain special adhesive monomers are necessary. To date, there are no clinical long-term data on resin bonding of partial-coverage high-strength ceramic or monolithic zirconia restorations.

Keywords: CAD; adhesives; cement; clinical outcomes; esthetic dentistry; prosthetic dentistry/prosthodontics.

Figure 1.

Dual-beam focused ion beam technology followed by scanning electron microscopy facilitates visual assessment of the bonding interface between a composite resin luting agent (left) and zirconia ceramic (right) without preparation artifacts.

Figure 2.

Without any surface pretreatment, the resin-zirconia bonding interface reveals wide-open gaps and only limited adhesion (×35,000 magnification).

Figure 3.

Air-particle abrasion of the zirconia surface with alumina particles (50 µm at 2 bar for 5 s) and application of a ceramic primer that contains phosphate monomers that chemically bond to oxide ceramics provide an optimized adhesive interface (×25,000 magnification).