Adhesion Screening of Dental Implant Materials Using Laser-Driven Acoustic Waves

Bacteria accumulation on implants and devices within the oral cavity puts a patient at serious risk for infection. Eradication of established biofilm-forming infections remains difficult, in part because the accumulated bacteria are physiologically and metabolically distinct from the planktonic cells of the same organism. Despite intense efforts in the field, biofilm level response to treatments and changes in environment has been hindered by the lack of robust, quantitative, and accurate biofilm characterization techniques that can be directly correlated to implant surfaces. Accurate biofilm adhesion measurement techniques are necessary because strong biofilm adhesion contributes to biofilm persistence on medical device surfaces. In order to more accurately assess the characteristics and contribution of biofilm adhesion on implant infections, an appropriate film adhesion measurement technique must be developed for evaluation of low cohesive strength-high adhesive strength biofilm-substrate interfaces. The proposed investigation is designed to overcome current limitations in biofilm adhesion measurement techniques by harnessing laser-induced acoustic waves. We recently discovered a new technique that generates stress waves from a pulsed laser is capable of separating a biofilm from a surface. This discovery is especially important for biofilms with low cohesive strengths because existing measurement techniques perform poorly on these biofilms, whereas, our newly discovered technique is well-suited for characterizing these types of biofilms. Controlling the amplitude of the generated stress waves from a pulsed laser enables a direct comparison of the stress required for biofilm detachment. We will assess and optimize the laser spallation technique for quantitative biofilm adhesion strength measurement, evaluate changes in adhesion due to surface treatments (e.g., roughness, polymer coating). Successful completion of this research results in new tools for quantitative adhesion measurement of biofilm-surface interfaces. Implementation of this technology will enable rational selection of implant materials for reduced biofilm adhesion and improved clinical outcomes