High speed imaging of biofilm removal from a dental implant model using ultrasonic cavitation

• Published in: Dental materials 2020-06, Vol.36 (6), p.733-743
• Main Authors: Vyas, Nina, Grewal, Meher, Kuehne, Sarah A., Sammons, Rachel L., Walmsley, A. Damien
• Format: Article
• Language: English
• Subjects: Biofilm disruption; Biofilms; Bubbles; Cavitation; Cleaning; Dental implants; Dental prosthetics; Dentistry; High speed; High speed cameras; Image analysis; Image processing; Implant debridement; Scalers; Scanning electron microscopy; Streptococcus infections; Ultrasonic cleaning; Water tanks
• ISSN: 0109-5641; 1879-0097
• DOI: 10.1016/j.dental.2020.03.003

Current instruments cannot clean in between dental implant threads and effectively remove biofilm from the rough implant surface without damaging it. Cavitation bubbles have the potential to disrupt biofilms. The aim of this study was to see how biofilms can be disrupted using non-contact cavitation from an ultrasonic scaler, imaged inside a restricted implant pocket model using high speed imaging. Streptococcus sanguinis biofilm was grown for 7 days on dental implants. The implants were placed inside a custom made restricted pocket model and immersed inside a water tank. An ultrasonic scaler tip was placed 0.5mm away from the implant surface and operated at medium power or high power for 2s. The biofilm removal process was imaged using a high speed camera operating at 500 fps. Image analysis was used to calculate the amount of biofilm removed from the high speed images. Scanning electron microscopy was done to visualize the implant surface after cleaning. Cavitation was able to remove biofilm from dental implants. More biofilm was removed at high power. Scanning electron microscopy showed that the implant surface was clean at the points where the cavitation was most intense. High speed imaging showed biofilm removal underneath implant threads, in areas next to the ultrasonic scaler tip. A high speed imaging protocol has been developed to visualize and quantify biofilm removal from dental implants in vitro. Cavitation bubbles from dental ultrasonic scalers are able to successfully disrupt biofilm in between implant threads.