Details

Autor(en) / Beteiligte

• Oei, James D
• Mishriky, Maged
• Barghi, Nasser
• Rawls, H. Ralph
• Cardenas, H. Lee
• Aguirre, Rene
• Whang, Kyumin

Titel

Development of a low-color, color stable, dual cure dental resin

Ist Teil von

• Dental materials, 2013-04, Vol.29 (4), p.405-412

Ort / Verlag

England: Elsevier Ltd

Erscheinungsjahr

2013

Quelle

MEDLINE

Beschreibungen/Notizen

• Abstract Dual-cure (DC) resins are mainly used as cements due to high initial color (generally yellow) and large color shift (Δ E *) after polymerization as compared to light-cured resins. However, even as cements, this color shift is clinically unacceptable, especially when used to cement thin veneers. Objective To develop a novel DC initiator system with both lower initial color (less yellow, i.e., whiter) and smaller Δ E *. Methods The effect of using an allyl thiourea (T)/cumene hydroperoxide (CH) self-cure (SC) initiator system in combination with a photo-co-initiator, p-octyloxy-phenyl-phenyl iodonium hexafluoroantimonate (OPPI), in a commercial DC resin cement (PermaFlo DC, Ultradent Products, Inc.) was investigated. Initial color and Δ E * were assessed for 6 weeks in vitro under accelerated aging conditions (75 °C water bath). Rockwell15T hardness was used to assess degree of cure (DoC) and the three-point bending test was used to assess mechanical properties. Results PermaFlo DC (control) was significantly harder than all experimental groups without OPPI but had up to three times higher initial color and four times greater color shift (Δ E * = 27 vs. 8). With OPPI, hardness in the experimental groups increased significantly and several were comparable to the controls. Initial color and Δ E * increased slightly (Δ E * = 9), but was still 3 times less than that of PermaFlo DC. DC samples containing OPPI had comparable modulus and ultimate transverse strengths to those of the controls. Conclusions DC resins that use the T/CH initiator system are weaker but have extremely low color and Δ E *. The addition of OPPI increases DoC and mechanical properties to clinically acceptable levels and maintains extremely low color and Δ E *. Significance With this novel initiator system, DC resins potentially can now have comparable color and color stability to light-cure resins and be used in broader esthetic dental applications to improve color stability and reduce shrinkage stress in restorative composites.