Current Molecular Technologies for Assessing the Amount of Microbial Pathogens in Oral Plaque Biofilms

Abstract

The goal of identifying and quantifying defined oral microbial populations has gained increasing importance in clinical dentistry. Standard laboratory culture-based procedures - despite their importance for the generation of resistance profiles - are unfortunately inadequate to grow the majority of mainly anaerobic species that predominate at pathological sites, such as periodontal pockets or infected root canals. Conversely, the rapidly evolving field of nucleic-acid-based technologies is a promising approach to access the full breadth of the oral microflora. Critical to this development, however, is a proper understanding and application of the methodologies and knowledge of their limitations. In this chapter molecular tools based on real-time quantitative polymerase chain reaction (RTQ-PCR) will be described along with ways showing the computation and analysis of the datasets. RTQ-PCR allows the determination of the amount of almost any given bacterial species or the total bacterial load in oral clinical sample in a sensitive and highly reproducible way. The precise and time-efficient nature of this technique allows to run large numbers of samples and if several bacterial targets are studied in parallel to study the dynamics and potential interactions of microbial populations over space and time. This chapter will be complemented by discussing potential pitfalls that should be taken into consideration for producing proper results along with referring the reader to pertinent literature that will allow an individual deepening into the concept of molecular-based diagnosis in clinical dentistry.