Marginal Bone Loss in Implants Placed in Grafted Maxillary Sinus Pablo Galindo-Moreno, DDS, PhD;* Andrés Fernández-Jiménez, DDS, PhD; † Francisco O’Valle, MD; ‡ Francisco J. Silvestre, MD, PhD; § Elena Sánchez-Fernández, MD, PhD; ¶ Alberto Monje, DDS;** Andrés Catena, PhD †† ABSTRACT Purpose: The purpose of this study is to evaluate the vertical and horizontal graft bone resorption (GR) in grafted maxillary sinuses and the marginal bone loss (MBL) around implants placed in the sinuses with different prosthetic connections and to determine the effect of other clinical factors on these tissue responses at 6 and 18 months postloading. Material and Method: A total of 254 implants were placed in 150 grafted maxillary sinuses of 101 patients (51.5% female) with mean age of 52.2 years (range, 32–82 years). GR and MBL measurements were made in implants placed with two different prosthetic connections (internal and external) at 6 and 18 months postloading. The complex samples general linear model was used to analyze the influence of patient age, gender, smoking habit, history of periodontal disease, implantation timing (simultaneous vs deferred), and prosthetic abutment length on radiographic GR and MBL values. Results: At 18 months postloading, the MBL ranged from 0 mm to 5.89 mm; less than 1 mm was lost around 49.0% (mesial) and 44.3% (distal) of the implants, while no bone was lost around 32.9% (mesial) and 26.7% (distal). The GR was significantly affected by smoking, remnant alveolar bone height, graft length, graft height, gender, and age, and it signifi- cantly decreased over time. The MBL was influenced by the type of connection, implantation timing, and prosthetic abutment length. The MBL was greater with longer postloading interval and higher patient age and in smokers. Conclusion: Resorption of grafts that combine autogenous cortical bone with anorganic bovine bone is dependent on the anatomic features of the sinus and is not affected by the time elapsed after the first 6 months. The MBL in implants placed in these grafted areas is time dependent and mainly related to potentially modifiable clinical decisions and patient habits. KEY WORDS: bone resorption, grafted bone, implant, marginal bone loss, maxilla bone, prosthetic connection INTRODUCTION Maxillary sinus elevation has proved to be a highly predictable clinical procedure to restore patients with posterior bone atrophy or extensive pneumatization. Numerous techniques and a large number of biomate- rials have proven effective to achieve satisfactory clinical outcomes, but there is considerable debate about the optimal method. Good success rates have recently been reported applying modified techniques without utilizing biomaterials by means of a lateral 1 or crestal 2 approach. The aim of these techniques is to produce new mature bone in the maxillary area to permit implan- tation and restore occlusal function for the longest possible time period. Relevant outcomes for their evalu- ation include the maturation and stabilization of the new bone created and the long-term functional per- formance of the implants placed in it. *Oral Surgery and Implant Dentistry Department, School of Dentistry, University of Granada, Granada, Spain; † Oral Surgery and Implant Dentistry Department, School of Dentistry, University of Granada, Granada, Spain; ‡ Department of Pathology. School of Medicine & IBIMER. University of Granada. Granada. Spain; § Department of Stomatology, School of Dentistry. University of Valencia, Valencia, Spain; ¶ Oral Surgery and Implant Dentistry Department, School of Dentistry, University of Granada, Granada, Spain; **Department of Periodontics and Oral Medicine, School of Dentistry, University of Michigan, Ann Arbor, USA; †† Department of Experimental Psychology, School of Psychology, University of Granada, Granada, Spain Reprint requests: Dr. Pablo Galindo-Moreno, C/ Recogidas, 39 5° Izq, 18005 Granada, Spain; e-mail: pgalindo@ugr.es Source of funding This study was partially supported by Junta de Andalucía Funding Program for research groups in Spain (Projects #CTS-138 and #CTS-583). © 2013 Wiley Periodicals, Inc. DOI 10.1111/cid.12092 373