©2016 by Quintessence Publishing Co Inc. 1264 Volume 31, Number 6, 2016 Influence of Four Different Abutment Materials and the Adhesive Joint of Two-Piece Abutments on Cervical Implant Bone and Soft Tissue Christian Mehl, Dr Med Dent Habil 1 /Volker Gaßling, Dr Med Dr Med Dent Habil 2 / Stephan Schultz-Langerhans, Doctoral Student 3 /Yahya Açil, Prof Dr Rer Nat 4 /Telse Bähr, Dr Med Vet 5 / Jörg Wiltfang, Prof Dr Med Dr Med Dent 6 /Matthias Kern, Prof Dr Med Dent Habil 7 Purpose: The main aim of this study was to evaluate the influence of four different abutment materials and the adhesive joint of two-piece abutments on the cervical implant bone and soft tissue. Materials and Methods: Sixty-four titanium implants (Camlog Conelog; 4.3 × 9 mm) were placed bone level into the edentulous arches of four minipigs. Four different types of abutments were placed at implant exposure: zirconium dioxide, lithium disilicate, and titanium bonded to a titanium luting base with resin cement; one-piece titanium abutments served as the control. The animals were sacrificed 6 months after implant exposure, and the bone-to-implant contact (BIC) area, sulcus depth, the length of the junctional epithelium and the connective tissue, the biologic width, and first cervical BIC–implant shoulder distance were measured using histomorphometry and light and fluorescence microscopy. Results: Overall, 14 implants were lost (22%). At exposure, the implant shoulder–bone distance was 0.6 ± 0.7 mm. Six months later, the bone loss was 2.1 ± 1.2 mm measured histomorphometrically. There was a significant difference between the two measurements (P ≤ .0001). No significant influence could be found between any of the abutment materials with regard to bone loss or soft tissue anatomy (P > .05), with the exception of zirconium dioxide and one- piece titanium abutments when measuring the length of the junctional epithelium (P ≤ .01). The maxilla provided significantly more soft tissue and less bone loss compared with the mandible (P ≤ .02). Conclusion: All tested abutment materials and techniques seem to be comparable with regard to soft tissue properties and the cervical bone level. INT J ORAL MAXILLOFAC IMPLANTS 2016;31:1264–1272. doi: 10.11607/jomi.5321 Keywords: animal study, bone, cell adhesion, cytology, dental implants, minipigs, osseointegration, osteoblasts, osteogenesis, soft tissue F or most dental implant systems, abutments are needed for restoration prosthetically. They can be made of different materials and manufactured in numerous ways. 1,2 Abutments are mostly produced from only one material (one-piece abutment), or are made from two parts (two-piece abutment). Nowa- days, if two materials are involved, the individual abutment part is bonded with resin cement to an in- dustrially prefabricated titanium base. 1–3 The most common abutment materials are titanium one-piece abutments, 1,2 cast gold abutments (eg, UCLA abut- ments), 1,2 zirconium dioxide abutments (one-piece- and two-piece abutments), 1,2 and most recently, lithium disilicate two-piece abutments. 4 Besides sta- bility, modern dental implant abutments should com- prise the following characteristics: (1) ensure stable soft and hard tissue results 2,5,6 ; (2) produce no wear in connection with the implant body 7–9 ; (3) provide a low accumulation of plaque 10,11 ; and (4) be biocompatible (no allergic reactions, no stimulation of the immune system) 12–14 and ideally should not discolor the gingi- val aspects, eg, due to metal implant components. 15 Ceramic and titanium abutments have shown comparable medium-term survival rates. 1 The cervi- cal bone level was unaffected by titanium, gold, and 1 Researcher, Formerly Assistant Professor, Department of Prosthodontics, Propaedeutics and Dental Materials, Christian-Albrechts University at Kiel, Kiel, Germany. 2 Associate Professor, Department of Oral and Maxillofacial Surgery, Christian-Albrechts University at Kiel, Kiel, Germany. 3 Private Practice, Flensburg, Germany. 4 Researcher, Department of Oral and Maxillofacial Surgery, Christian-Albrechts University at Kiel, Kiel, Germany. 5 Researcher, Private Practice, Lehmkuhlen, Germany. 6 Chair, Department of Oral and Maxillofacial Surgery, Christian- Albrechts University at Kiel, Kiel, Germany. 7 Chair, Department of Prosthodontics, Propaedeutics and Dental Materials, Christian-Albrechts University at Kiel, Kiel, Germany. Correspondence to: Dr Christian Mehl, Department of Prosthodontics, Propaedeutics and Dental Materials, Christian- Albrechts University at Kiel, Arnold-Heller-Straße 16, Germany. Fax: +49-431-500 26404. Email: cmehl@proth.uni-kiel.de © 2016 BY QUINTESSENCE PUBLISHING CO, INC. PRINTING OF THIS DOCUMENT IS RESTRICTED TO PERSONAL USE ONLY. NO PART MAY BE REPRODUCED OR TRANSMITTED IN ANY FORM WITHOUT WRITTEN PERMISSION FROM THE PUBLISHER.