Original Article The Role of Biofilms and Material Surface Characteristics in Microbial Adhesion to Maxillary Obturator Materials: A Literature Review Karl M. Lyons, BDS, MDS, PhD 1 , Richard D. Cannon, MA, PhD 2 , John Beumer III, DDS, MS 3 , Mahmoud M. Bakr, BDS, MDS 4 , and Robert M. Love, BDS, MDS, PhD 4 Abstract Background: Maxillofacial prosthetics includes restoration of maxillary defects resulting from resection of palate and nasosinus neoplasms with obturator prostheses which may be colonized by microorganisms and function as a reservoir of infection. Patients with neoplasms commonly also require radiotherapy that can result in changes in saliva quality and quantity and changes in the oral microbial flora. The altered flora, in individuals immunocompromised from cancer therapy, increases their risk of prosthesis- related infections. Objectives: In this review article, we explore microbial biofilms, their main components, mechanisms of microbial adhesion, and stages of biofilm development. We also discuss the different materials that are used for manufacturing maxillary obturators, their characteristic features, and how these can affect microbial adhesion. Furthermore, we shed some light on the factors that affect microbial adhesion to the surface of maxillary obturators including tissue proteins, protein adsorption, and the acquired enamel pellicle. Conclusions: The conclusions drawn from this literature review are that it is imperative to minimize the risk of local and systemic infections in immunocompromised patients with cancer having maxillary defects. It is also important to determine the role of saliva in microbial adhesion to obturator materials as well as develop materials that have a longer life span with surface char- acteristics that promote less microbial adhesion than current materials. Keywords microbiology, maxillary obturators, biofilm, adhesion, mucositis Introduction Prosthetic devices such as catheters, artificial heart valves, orthopedic implants, ocular prostheses, contact lenses, silicone voice prostheses, dentures, and maxillary obturators can be colonized by microorganisms that form an adherent biofilm on the surface of the device (Bryers, 2008). Adhering microbial cells in a biofilm are organized into structured communities enclosed within a matrix of extracellular material (Hall- Stoodley and Stoodley, 2009; Kolenbrander et al., 2010). They are phenotypically different from planktonic or suspended cells, they resist host defenses, and display a significantly decreased susceptibility to antimicrobial agents (Fux et al., 2005). Regardless of the sophistication of an implant or device, all are susceptible to microbial colonization and can cause infection (Bryers, 2008). Maxillofacial prosthetics includes restoration of maxillary defects that may develop congenitally (cleft palate), be acquired following surgery (including for maxillary tumors), 1 Department of Oral Rehabilitation and Sir John Walsh Research Institute, Faculty of Dentistry, University of Otago, Dunedin, New Zealand 2 Faculty of Dentistry, Sir John Walsh Research Institute, University of Otago, Dunedin, New Zealand 3 Division of Advanced Prosthodontics, School of Dentistry, University of California, Los Angeles, CA, USA 4 School of Dentistry and Oral Health, Griffith University, Queensland, Australia Corresponding Author: Mahmoud M. Bakr, School of Dentistry and Oral Health, Griffith University, Queensland 4222, Australia. Email: m.bakr@griffith.edu.au The Cleft Palate-Craniofacial Journal 1-12 ª 2019, American Cleft Palate- Craniofacial Association Article reuse guidelines: sagepub.com/journals-permissions DOI: 10.1177/1055665619882555 journals.sagepub.com/home/cpc