Longitudinal changes in subgingival biofilm composition following periodontal treatment.

BACKGROUND: Current periodontal treatment involves instrumentation using hand and/or ultrasonic instruments, which are used either alone or in combination based on patient and clinician preference, with comparable clinical outcomes. This study sought to investigate early and later changes in the subgingival biofilm following periodontal treatment, to identify whether these changes were associated with treatment outcomes, and to investigate whether the biofilm responded differently to hand compared with ultrasonic instruments. METHODS: This was a secondary-outcome analysis of a randomized-controlled trial. Thirty-eight periodontitis patients received full-mouth subgingival instrumentation using hand (n = 20) or ultrasonic instrumentation (n = 18). Subgingival plaque was sampled at baseline and 1, 7, and 90 days following treatment. Bacterial DNA was analyzed using 16S rRNA sequencing. Periodontal clinical parameters were evaluated before and after treatment. RESULTS: Biofilm composition was comparable in both (hand and ultrasonics) treatment groups at all time points (all genera and species; p[adjusted] > 0.05). Large-scale changes were observed within groups across time points. At days 1 and 7, taxonomic diversity and dysbiosis were reduced, with an increase in health-associated genera including Streptococcus and Rothia equating to 30% to 40% of the relative abundance. When reassessed at day 90 a subset of samples reformed a microbiome more comparable with baseline, which was independent of instrumentation choice and residual disease. CONCLUSIONS: Hand and ultrasonic instruments induced comparable impacts on the subgingival plaque microbiome. There were marked early changes in the subgingival biofilm composition, although there was limited evidence that community shifts associated with treatment outcomes.

Aerosol reduction efficacy of different intra-oral suction devices during ultrasonic scaling and high-speed handpiece use.

BACKGROUND: The COVID-19 pandemic led to significant changes in the provision of dental services, aimed at reducing the spread of respiratory pathogens through restrictions on aerosol generating procedures (AGPs). Evaluating the risk that AGPs pose in terms of SARS-CoV-2 transmission is complex, and measuring dental aerosols is challenging. To date, few studies focus on intra-oral suction. This study sought to assess the effectiveness of commonly used intra-oral suction devices on aerosol mitigation. METHODS: Ultrasonic scaling and high-speed handpiece procedures were undertaken to generate aerosol particles. Multiple particle sensors were positioned near the oral cavity. Sensor data were extracted using single board computers with custom in-house Bash code. Different high-volume and low-volume suction devices, both static and dynamic, were evaluated for their efficacy in preventing particle escape during procedures. RESULTS: In all AGPs the use of any suction device tested resulted in a significant reduction in particle counts compared with no suction. Low-volume and static suction devices showed spikes in particle count demonstrating moments where particles were able to escape from the oral cavity. High-volume dynamic suction devices, however, consistently reduced the particle count to background levels, appearing to eliminate particle escape. CONCLUSIONS: Dynamic high-volume suction devices that follow the path of the aerosol generating device effectively eliminate aerosol particles escaping from the oral cavity, in contrast to static devices which allow periodic escape of aerosol particles. Measuring the risk of SARS-CoV-2 transmission in a dental setting is multi-factorial; however, these data suggest that the appropriate choice of suction equipment may further reduce the risk from AGPs.

Post-traumatic stress disorder symptoms in the files of Australian servicemen hospitalized in 1942-1952.

OBJECTIVE: To investigate post-traumatic stress disorder (PTSD) symptomatology in servicemen hospitalized 1942-1952. METHOD: Hospital files of servicemen (n = 590) were studied and PTSD symptoms in groups, based on service experience, were compared. RESULTS: Based on their hospital files, 19% of servicemen were classified as having partial PTSD. No full cases of PTSD were identified, due primarily to the small number of recorded avoidance symptoms and the limited information in relation to the stressor criterion. Prisoners of war had the highest reported avoidance and lowest intrusive symptoms compared with other combatants. CONCLUSIONS: PTSD symptoms may have been common during and after World War II. At that time avoidance was not considered a symptom of disorder. Intrusive and arousal symptoms may be the core symptoms of PTSD and avoidance symptoms need to be reconsidered.

Follow up of post-traumatic stress disorder symptoms in Australian servicemen hospitalized in 1942-1952.

OBJECTIVE: To follow up survivors of Australian services hospitalized in 1942-1952 and compare their reported symptoms of post-traumatic stress disorder (PTSD) with symptoms in their hospital files. METHOD: Twelve survivors were interviewed and combatants completed the revised Impact of Event Scale. RESULTS: Eight survivors had symptoms satisfying a diagnosis of PTSD at the time of the study. There was underreporting of most relevant symptoms in their hospital files. CONCLUSIONS: PTSD symptoms were probably common during and after World War II. The findings have implications for the management of PTSD generally and the treatment of ageing WWII veterans in particular.