Dental implants are used extensively to replace missing teeth. To enhance their integration with the bones of the jaws, the surfaces of titanium dental implants are modified to make them hydrophilic, high energy, and microtextured. These same features make biofilm development occur readily upon exposure to the saliva. The presence of mature biofilms on dental implant surfaces drives local inflammatory responses in the adjacent soft and hard tissues (peri-implantitis), which leads to pathological loss of bone and the formation of a saucer shaped bone defects. This chapter examines the unique challenges posed by biofilms formed on highly complex dental implant surfaces, which are difficult to access for cleaning, and easily damaged by conventional cleaning approaches. We explore how biofilms can be removed from implant surfaces using a variety of novel methods, without causing surface damage or other undesirable modifications, and show how different laboratory and clinical models can be used to assess the performance of both conventional and novel methods of biofilm removal.
Part of the book: Microbial Biofilms
In endodontic (root canal) treatment, a multispecies bacterial and fungal infection is present in a place that is inaccessible to the host immune system and which offers physical protection from applied topical agents. All current protocols for irrigation suffer various deficits in performance, which is why further research on alternative approaches to using antimicrobial substances is warranted. This chapter examines the technical and clinical factors which influence the performance of antimicrobial biocide-based therapies used in endodontics within dental practice, addressing issues around instability of biocides, the influence of pH, the role of physical agitation and the challenge of penetration into biofilms and into confined spaces. A range of methods to overcome the challenges in performance are described, including novel solvents and vehicles for biocides, stabilizing agents, physical agitation and the use of activation protocols including the use of intense light, ultrasound and laser-generated shockwaves to improve the effect of biocides. While specific examples are given from the dental setting of endodontics, the principles have broader application to medicine and to general industry.
Part of the book: Antibacterial Agents
Microbial biofilms are complex multi-layered communities of bacteria and fungi which cause a range of oral and other diseases. Efficient detection of biofilms is important for the clinical management of diseases they cause and for providing an endpoint to clinical treatments. For bacterial biofilms, bacterial metabolites such as porphyrins are important molecules for diagnostic purposes, since they fluoresce in the red and infrared regions of the spectrum. Fluorescence is a versatile and powerful diagnostic approach for detection of bacterial biofilms, particularly in dentistry. This chapter provides an overview of fluorescence spectroscopic methods for detection and analysis of biofilms and their derivatives such as deposits of dental calculus and how current technology can be extended using photon-counting detectors. Fluorescence can be used to help discriminate these from healthy tissues. The approaches described have broad applications to clinical and industrial situations where non-invasive detection of microbial biofilms is important.
Part of the book: Photon Counting
Because of the limitations of visual inspection and dental radiographs for detecting early or hidden forms of dental caries, much effort has been expended developing additional methods to supplement traditional examination, Foremost amongst these has been fluorescence, which exploits the light emitting properties of bacteria deposits or of normal tooth structure. Key considerations when using fluorescence are the differences between the light emitting properties of carious versus sound tooth structure, the excitation wavelengths of light that are chosen, and the methods used to analyze fluorescence emissions. Provided that technical issues such as false positive and negative signals can be addressed, devices that employ fluorescence can improve the detection and management of dental caries, and help guide the removal of carious tooth structure during restorative procedures. Clinical recommendations for using fluorescence as an aid to caries diagnosis are based on appreciating the effects of moisture, stains, and quenching agents on readings, and altering the ambient light conditions to maximize the signal to noise ratio. Any quantitative fluorescence techniques require calibration of the device, and checks for contamination of the optics. Differences in the performance of fluorescence devices must also be considered when comparing results against thresholds for intervention.
Part of the book: Dental Caries
The performance of clinicians undertaking periodontal assessment or periodontal therapy can be improved by using optical methods as adjuncts to visual inspection and periodontal probing. Subtle changes that occur over time in periodontal tissues that are below the detection limit of visual examination or periodontal probing can be found and tracked accurately over time using 3D imaging, fluorescence spectroscopy, and optical coherence tomography. During debridement of teeth and dental implants, the effective removal of subgingival microbial biofilms and dental calculus deposits can be enhanced using magnifying loupes and operating microscopes and by novel methods based on the interactions of light with bacterial deposits, such as differential reflectometry and light-induced fluorescence. While such techniques can also be used using initial case assessment, their primary purpose is for checking debridement procedures, since the point when bacterial deposits are no longer present represents an endpoint for treatment. The concept of real-time feedback has been developed, using fluorescence readings to control the removal of deposits. Overall, optical methods can support traditional periodontal diagnosis and improve treatment planning and clinical periodontal care.
Part of the book: Periodontology and Dental Implantology