Why are the next steps in biomaterials research so difficult?

Strategically, ‘biomaterials research’ should be refocusing its science on new areas – but it has not! Traditionally, biomaterials research has been heavily leveraged in ‘synthetic biomaterials product-testing’, but it should be moving towards ‘biological materials and clinical research’. There is an adage (Lubin’s Rule) that says ‘If another scientist thought your research was more important than his, he would drop what he is doing and do what you are doing’ (1). This appropriately describes the struggle of biomaterials’ research investigators to try to move into the next age for biomaterials research. There are several historical impediments here, so let’s start at the beginning. Biomaterials research should encompass three major focuses: (i) complete characterization of the structureproperty events within restorative materials (synthetic or biological), (ii) the biological interactions at their interfaces with biological tissues, and (iii) the changing events of the underlying biological tissues. This interplay (materials, interfaces, tissues) has been the unrealized research goal for biomaterials’ scientists for many years. To date, the overwhelming focus has been on laboratory characterization material properties. John Keller (pers. comm., Northwestern University, Chicago, IL, USA) once opined that the ‘bio’ seemed to be missing from ‘biomaterials’. Two important transitions now are underway that begin to address the problems. Firstly, there is increasing pressure to understand interfaces and tissues as part of expanding focus on clinical research for biomaterials. Secondly, there is strong pressure for biomaterials scientists to embrace tissue engineering and move towards the development and testing of true ‘biological materials’ (2). Both of these transitions are part of the upcoming Journal of Oral Rehabilitation 2006 Summer School Workshop (theme: oral biomaterials – from material science to biology – the clinical consequences) on September 20–24 in Bevagna, Italy. Let’s consider each of these major transitions more carefully. Concern for the need for clinical research in biomaterials actually was first emphasized in the mid-1960 s by Ryge (3). While it has been popular in the last decade to call for evidence-based dentistry, the actual push began long ago. In the absence of financial incentives, clinical research has been severely hindered for many years. Despite this problem, Ryge led the effort to put into place a system for collecting information about the clinical performance of restorative materials (USPHS guidelines) that was based on ‘direct’ patient observations (4). Realizing the possible value of extending direct evaluation methods, Leinfelder (5) and others (6) embarked on using impression techniques to capture intra-oral morphologic data and create working casts for subsequent laboratory analysis of events. This ‘indirect’ approach has been the primary method for quantitative measurement monitoring of changes such as occlusal wear (7) over the last 25 years. Direct and indirect clinical research methods for restorative materials have only been able to evolve because of the funding support of dental materials manufacturers. Even then, their funding has been very limited in numbers and amounts. The National Institute for Dental and Craniofacial Research (NIDCR), until recently, has shown no interest in supporting clinical research of restorative materials. Since 2002, NIH (8) has declared a strong interest in conducting translational research and includes clinical research under that umbrella. However, that movement so far has been to increase clinical data collection and not to enhance clinical research techniques. Thus, clinical research involving biomaterials continues to be stalled for the short term. For most of the history of dental biomaterials research, the focus has been on the development and testing of ‘synthetic biomaterials’. However, since the mid-1990 s, there has been increasing interest and emphasis (particularly by NIH) in developing and testing ‘biological biomaterials’ that are associated with tissue engineering. While older biomaterials’ scientists may not have much depth in biological science, the materials’ science training of these same individuals would seem to position them well to apply those principles in arenas such as tissue engineering. Still, the migration of