Effects of sandblasting distance and angles on resin cement bonding to zirconia and titanium Beatrice Jane Ho a , James Kit-Hon Tsoi a,n , Dan Liu a , Christie Ying-Kei Lung a , Hai-Ming Wong b , Jukka P. Matinlinna a a Dental Materials Science, Faculty of Dentistry, The University of Hong Kong, Pokfulam, Hong Kong SAR, China b Paediatric Dentistry and Orthodontics, Faculty of Dentistry, The University of Hong Kong, Pokfulam, Hong Kong SAR, China article info Article history: Accepted 18 June 2015 Available online 25 June 2015 Keywords: Zirconia Titanium Adhesive strength Shear Implants Sandblasting Resin cement abstract Objectives: The aim of this study was to evaluate effects of sandblasting distance and angles resin to zirconia and titanium bonding. Methods: Densely sintered zirconia and cp2 titanium specimens were prepared and randomly divided into groups, and then sandblasted with various distance (5 mm,10 mm and 15 mm) and angles (45°, 60°, 75° and 90°). After surface treatment, each specimen surface underwent a silane primer application (RelyX, 3M ESPE), followed by bonding of a resin cement (RelyX Unicem Aplicap, 3M ESPE). Then, each cylindrical resin stub (diameter 3.6 mm  2 mm) underwent a shear adhesive (bond) strength test and surface roughness evaluation. SEM evaluation and EDX analysis were used to observe surface properties of both zirconia and titanium samples. Results were statistically analyzed using analysis of variance (ANOVA) and Turkey test (α ¼0.05). Results: Surface roughness showed a significant difference amongst the different distances and angles for both the zirconia and titanium materials and these changes in surface roughness were evident in the SEM imaging photos. As for the adhesive strength, there was a significant difference in the adhesive strength for the titanium and zirconia with different angles. In general, 75° gives the best results although this is not significantly different from 90°. However, no significant difference was observed in changes of sandblasting distance for both materials. EDX analysis at the surface revealed elements car- bon, oxygen, silicon, aluminum, and zirconia on the surface. Conclusions: Sandblasting at various distance and angles contributes differences in surface roughness when it comes to both zirconia and titanium materials. Despite both 75° or 90° sandblasting angle could yield a sufficiently high adhesive strength for resin to titanium or zirconia bonding, sandblasting at 75° seems to be optimal to increase the adhesive strength. & 2015 Elsevier Ltd. All rights reserved. 1. Introduction Titanium and also in a growingly extent zirconia are the two most commonly preferred materials for dental subgingival implants. These materials fulfill the safety and biomechanical standards that have been used and suggested by researchers and dentists to be the most ideal for dental implants and other indirect dental restorations [1,2]. Both these materials have superior strength that can endure the everyday occlusal forces that teeth may undergo and they also have excellent biocompatibility with- out any adverse side effects [3]. Zirconia is one of the most commonly studied current ceramic in dentistry. Its ability to take different forms at different tem- peratures makes the material very special and unique to other materials. The most desired characteristic of zirconia is its trans- lucent color and esthetic appeal [4]. Furthermore, the high bio- compatibility and osseointegration ability enrich the usage of zir- conia [5]. In fact, researchers have found that zirconia possesses similar mechanical properties to stainless steel. Some other applications for zirconia in dentistry include implant screws, abutments, bridges and crowns [6]. Titanium, on the other hand, has been the material of choice used for dental implants within the past several decades. Although titanium and its alloys are known for their biocompatibility, low Contents lists available at ScienceDirect journal homepage: www.elsevier.com/locate/ijadhadh International Journal of Adhesion & Adhesives http://dx.doi.org/10.1016/j.ijadhadh.2015.06.009 0143-7496/& 2015 Elsevier Ltd. All rights reserved. n Correspondence to: Dental Materials Science, Faculty of Dentistry, The Uni- versity of Hong Kong, 4/F, Prince Philip Dental Hospital, 34 Hospital Road, Sai Ying Pun, Hong Kong SAR, China. Tel.: þ852 2859 0303; fax: þ852 2548 9464. E-mail address: jkhtsoi@hku.hk (J.K.-H. Tsoi). International Journal of Adhesion & Adhesives 62 (2015) 25–31