Journal of International Dental and Medical Research ISSN 1309-100X Curing Mode in Universal Adhesive http://www.jidmr.com Awiruth Klaisiri and et al Volume ∙ 14 ∙ Number ∙ 3 ∙ 2021 Page 896 The Effect of Curing Mode in Universal Adhesive on Zirconia and Resin Cement Shear Bond Strength Awiruth Klaisiri 1 *, Nantawan Krajangta 1 , Panupat Phumpatrakom 2 , Tool Sriamporn 3 , Niyom Thamrongananskul 4 1. Division of Operative Dentistry, Faculty of Dentistry and Research Unit in Restorative and Esthetic Dentistry Thammasat University, Pathumthani, Thailand. 2. Division of Endodontics, Faculty of Dentistry, Thammasat University, Pathumthani, Thailand. 3. Department of Prosthodontics, College of Dental Medicine, Rangsit University, Pathumthani, Thailand. 4. Department of Prosthodontics, Faculty of Dentistry, Chulalongkorn University, Bangkok, Thailand. Abstract This study examined the effect of curing mode in the universal adhesive on the shear bond strength of zirconia and resin cement interface. Universal adhesive (Singlebond universal, SBU) and dual-cure activator (Singlebond universal dual-cure activator, DCA) were used. Forty zirconia disks were prepared and embedded in dental gypsum. The samples were randomly divided into four groups (n = 10) according to curing mode: group1 (No tx), group2 (SBU+LC), group3 (SBU+DCA+LC) and group4 (SBU+DCA). Silicone mold was placed on top of the treated zirconia surface. Resin cement was filled into the mold and subsequently stored in a yellow box for 30 minutes. All bonded specimens were kept in distilled water at 37 o C for 24 hours and they were subjected to bond strength measurement using a universal testing machine. The data were statistically analyzed using one-way ANOVA and Tukey’s test. The shear bond strengths of group1 to group4 were 6.13±2.45, 25.42±3.09, 24.26±1.98 and 17.38±2.76 MPa, respectively (P < 0.05). There was no statistical difference between group2 and group3 (P > 0.05). In conclusion, the light activation in the universal adhesive with/without DCA (dual-curing mode/light-curing mode) had a positive effect on zirconia and resin cement interface. Experimental article (J Int Dent Med Res 2021; 14(3): 896-900) Keywords: Curing mode, resin cement, universal adhesive, zirconia. Received date: 26 May 2021. Accept date: 08 July 2021 Introduction Zirconia has been recently introduced in restorative, prosthetic, and esthetic dentistry for the fabrication of crowns and fixed partial dentures. Zirconia has appeared as a versatile and promising material among dental ceramics, due to its biocompatible characteristics and excellent mechanical properties owing to the transformation toughening mechanism. 1-3 Its mechanical properties are very close to those of metals and its color similar to tooth color. 4 Retention of zirconia restorations depends on mechanical roughening of the zirconia surface 5,6 and chemical bonding with the adhesive functional monomer in special primers, adhesives, and resin cements. 7-9 An acidic adhesive functional monomer such as 10- methacryloyloxydecyl dihydrogen phosphate (10- MDP) bonds to zirconia-based ceramics. The phosphate functional group of the acidic monomer results in chemical adhesion to metal oxides, such as zirconia-based ceramics. Kim et al. reported that the addition of 10-MDP- containing monomer in the universal adhesive to enhance the bond strength of zirconia and resin cement interface. 9 In the past recent years, dental manufacturers have been developed a new trend of adhesive called “universal adhesive”. The term “universal” offers the creativity of use with a variety of direct and indirect dental restorative materials, capable of bonding to various restorative materials combined with appropriate surface treatments. 10 All the universal adhesive products tested were based on the 10-MDP acidic functional monomer with a documented adhesion capacity with the tooth, 11 titanium, base *Corresponding author: Asst. prof. Awiruth Klaisiri, Division of Operative dentistry, Faculty of Dentistry, Thammasat University, Thailand. E-mail: dentton@hotmail.com