Bruxism and Dental Implants: A Meta-Analysis Bruno Ramos Chrcanovic, DDS, MSc,* Tomas Albrektsson, MD, PhD,† and Ann Wennerberg, DDS, PhD‡ O cclusal parafunction includes bruxism (clenching, grinding), lip biting, thumb sucking, and abnormal posturing of the jaw. In con- trast to functional behaviors such as mastication, deglutition, or speaking, activities classified as “parafunctions” seem to have no functional purpose. 1 Concerning the overloading related to parafunction, it can cause various complications, such as occlusal sur- face wear, fracture, loosened screws, or abutment and implant fracture. 2 As the frequency of parafunction is very common, 1 the usage of implants in pa- tients with parafunctional habits is unavoidable. Moreover, a significantly high percentage of newly gained par- afunction was reported in patients with implant-supported superstructures. 3 Some authors have suggested that overloading of implants or abnormal occlusal stress, as seen in patients with bruxism habits, may contribute to fail- ure. 4 As the possible occurrence of parafunctional habits is evident in any stage of dental treatment, the risks for implant therapy must be consid- ered. 2 Therefore, bruxism is often con- sidered a contraindication for implant treatment although the evidence for this is usually based on clinical expe- rience only. 5 The ability to anticipate outcomes is an essential part of risk management in an implant practice. Recognizing conditions that place the patient at a higher risk of failure will allow the surgeon to make informed decisions and refine the treatment plan to opti- mize the outcomes. 6 The use of implant therapy in special populations requires consideration of potential benefits to be gained from the therapy. To better appreciate this potential, we conducted a systematic review and meta-analysis to compare the survival rate of dental implants, postoperative infection, and marginal bone loss of dental implants inserted in bruxers and non-bruxers patients. MATERIALS AND METHODS This study followed the PRISMA Statement guidelines. 7 A review proto- col does not exist. Objective The purpose of this review was to test the null hypothesis of no difference in the implant failure rates, postopera- tive infection, and marginal bone loss after the insertion of dental implants in patients being diagnosed as presenting bruxing habits compared with the inser- tion in non-bruxers against the alterna- tive hypothesis of a difference. The following focused question was raised: In patients being rehabilitated with dental implants, what is the effect of *PhD Student, Department of Prosthodontics, Faculty of Odontology, Malmö University, Malmö, Sweden. †Retired Professor and Former Head, Department of Biomaterials, Göteborg University, Göteborg, Sweden; Guest Professor, Department of Prosthodontics, Faculty of Odontology, Malmö University, Malmö, Sweden. ‡Professor and Head, Department of Prosthodontics, Faculty of Odontology, Malmö University, Malmö, Sweden. Reprint requests and correspondence to: Bruno Ramos Chrcanovic, DDS, MSc, Department of Prosthodontics, Faculty of Odontology, Malmö University, Carl Gustafs väg 34, SE-205 06, Malmö, Sweden, Phone: +46 725 541 545, Fax: +46 40 6658503, E-mail: bruno. chrcanovic@mah.se ISSN 1056-6163/15/00000-001 Implant Dentistry Volume 0  Number 0 Copyright © 2015 Wolters Kluwer Health, Inc. All rights reserved. DOI: 10.1097/ID.0000000000000298 Purpose: To test the null hypoth- esis of no difference in the implant failure rates, postoperative infection, and marginal bone loss after the insertion of dental implants in bruxers compared with the insertion in non-bruxers against the alterna- tive hypothesis of a difference. Methods: An electronic search was undertaken in June 2014. Eligi- bility criteria included clinical stud- ies, either randomized or not. Results: Ten publications were included with a total of 760 implants inserted in bruxers (49 failures; 6.45%) and 2989 in non-bruxers (109 failures; 3.65%). Due to lack of information, meta-analyses for the outcomes “postoperative infection” and “marginal bone loss” were not possible. A risk ratio of 2.93 was found (95% confidence interval, 1.48–5.81; P ¼ 0.002). Conclusions: These results can- not suggest that the insertion of dental implants in bruxers affects the implant failure rates due to a limited number of published stud- ies, all characterized by a low level of specificity, and most of them deal with a limited number of cases without a control group. Therefore, the real effect of bruxing habits on the osseointegration and survival of endosteal dental implants is still not well established. (Implant Dent 2015;0:1–12) Key Words: dental implants, brux- ism, implant failure rate, meta- analysis IMPLANT DENTISTRY /VOLUME 0, NUMBER 0 2015 1 Copyright Ó 2015 Wolters Kluwer Health, Inc. Unauthorized reproduction of this article is prohibited.