Microbiological cleaning and disinfection efficacy of a three-stage ultrasonic processing protocol for CAD-CAM implant abutments

Abstract

PURPOSE Computer-aided design and manufacturing (CAD-CAM) of implant abutments has been shown to result in surface contamination from site-specific milling and fabrication processes. If not removed, these contaminants can have a potentially adverse effect and may trigger inflammatory responses of the peri-implant tissues. The aim of the present study was to evaluate the bacterial disinfection and cleaning efficacy of ultrasonic reprocessing in approved disinfectants to reduce the microbial load of CAD-CAM abutments. MATERIALS AND METHODS Four different types of custom implant abutments (total N = 32) with eight specimens in each test group (type I to IV) were CAD-CAM manufactured. In two separate contamination experiments, specimens were contaminated with heparinized sheep blood alone and with heparinized sheep blood and the test bacterium Enterococcus faecium. Abutments in the test group were processed according to a three-stage ultrasonic protocol and assessed qualitatively and quantitatively by determination of residual protein. Ultrasonicated specimens contaminated with sheep blood and E. faecium were additionally eluted and the dilutions were incubated on agar plates for seven days. The determined bacterial counts were expressed as colony-forming units (CFU). RESULTS Ultrasonic reprocessing resulted in a substantial decrease in residual bacterial protein to less than 80 µg and a reduction in microbiota of more than 7 log levels of CFU for all abutment types, exceeding the effect required for disinfection. CONCLUSION A three-stage ultrasonic cleaning and disinfection protocol results in effective bacterial decontamination. The procedure is reproducible and complies with the standardized reprocessing and disinfection specifications for one- or two-piece CAD-CAM implant abutments.

Influence of exposure of customized dental implant abutments to different cleaning procedures: an in vitro study using AI-assisted SEM/EDS analysis

“…The most significant difference in the contamination level between the FP/NC, CP/NC, UD/NC and PL/NC groups should be highlighted. The results are consistent with Canullo et al and Gehrke et al, who also reported superior ultrasonic cleaning for residual and bacterial decontamination [ 2 , 5 , 37 ]. The most effective surface cleanliness for ultrasonic cleaning was measured by Canullo et al at 0.0007%; generally higher contamination levels were measured for two-piece abutments as detected by Gehrke et al, even with multi-stage ultrasonic cleaning, which is also consistent with the current measurements [ 2 , 5 ].…”

Influence of exposure of customized dental implant abutments to different cleaning procedures: an in vitro study using AI-assisted SEM/EDS analysis

“…The highest surface cleanliness was achieved by chemothermal ultrasonic cleaning (CP, FP and UD) and argon-oxygen plasma treatment (PL) (Table 4, Table 5). These results are consistent with Canullo et al and Gehrke et al, who also reported superior ultrasonic cleaning for residual and bacterial decontamination (2,5,37). The most signi cant differences in contamination levels were found between the FP/NC, CP/NC, UD/NC, and PL/NC groups.…”

Effect of autoclaving on implant abutments from genesis and bredent dental implant systems

“…While sterilisation does have an effect on the mechanical properties of the implant surface, titanium implants are particularly susceptible to this effect. There are studies that have shown that the sterilisation process in the autoclave is responsible for the alteration in the mechanical characteristics that leads to plastic deformation in steel materials when they are subjected to high levels of stress [ 26 , 27 ,28]. Mathew et al examined the mechanical properties of titanium and stainless steel mini-plates before and after repeated autoclaving cycles and found that the values were not constant.…”