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

A global genomic approach uncovers novel components for twitching motility-mediated biofilm expansion in Pseudomonas aeruginosa.

Pseudomonas aeruginosa is an extremely successful pathogen able to cause both acute and chronic infections in a range of hosts, utilizing a diverse arsenal of cell-associated and secreted virulence factors. A major cell-associated virulence factor, the Type IV pilus (T4P), is required for epithelial cell adherence and mediates a form of surface translocation termed twitching motility, which is necessary to establish a mature biofilm and actively expand these biofilms. P. aeruginosa twitching motility-mediated biofilm expansion is a coordinated, multicellular behaviour, allowing cells to rapidly colonize surfaces, including implanted medical devices. Although at least 44 proteins are known to be involved in the biogenesis, assembly and regulation of the T4P, with additional regulatory components and pathways implicated, it is unclear how these components and pathways interact to control these processes. In the current study, we used a global genomics-based random-mutagenesis technique, transposon directed insertion-site sequencing (TraDIS), coupled with a physical segregation approach, to identify all genes implicated in twitching motility-mediated biofilm expansion in P. aeruginosa. Our approach allowed identification of both known and novel genes, providing new insight into the complex molecular network that regulates this process in P. aeruginosa. Additionally, our data suggest that the flagellum-associated gene products have a differential effect on twitching motility, based on whether components are intra- or extracellular. Overall the success of our TraDIS approach supports the use of this global genomic technique for investigating virulence genes in bacterial pathogens

The systemic inflammatory response following hand instrumentation versus ultrasonic instrumentation—a randomized controlled trial

Objective: This study sought to investigate whether the immediate systemic inflammatory response following full mouth debridement differs following use of hand compared with ultrasonic instruments. Methods: Thirty‐nine periodontitis patients were randomised to treatment with full‐mouth debridement using either hand or ultrasonic instrumentation completed within 24 hours. Serum and periodontal clinical parameters were collected at baseline, day 1, day 7 and day 90 post‐treatment. Differences in systemic inflammatory markers were assessed using general linear models at each time‐point, corrected for age, gender, smoking status, body mass index and baseline levels of each marker. Results: Across all patients, serum C‐reactive protein increased at day 1, with no differences between hand and ultrasonic groups (p(adjusted)=0.22). There was no difference between groups in interleukin‐6 (p(adjusted)=0.29) or tumour necrosis factor α (p(adjusted)=0.53) at day 1. Inflammatory markers returned to baseline levels by day 7. Treatment resulted in equal and marked improvements in clinical parameters in both groups; however, total treatment time was on average shorter for ultrasonic instruments (p(adjusted)=0.002). Conclusions: Ultrasonic instrumentation resulted in shorter treatment time with comparable clinical outcomes. Levels of serum C‐reactive protein at day 1 were similar following debridement with hand or ultrasonic instruments

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 randomised 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 analysed 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 timepoints (all genus and species; p[adjusted]>0.05). Large-scale changes were observed within-groups across timepoints. At days 1 and 7, taxonomic diversity and dysbiosis were reduced, with an increase in health-associated genera including Streptococcus and Rothia equating to 30-40% 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

Clinical and patient‐centered outcomes post non‐surgical periodontal therapy with the use of a non‐injectable anesthetic product: A randomized clinical study

Abstract AIM: The aim of this study was to determine the impact of different full-mouth decontamination (FMD) protocols on the effectiveness of an intrapocket anesthetic gel in periodontal maintenance patients. METHODS: Patients undergoing the periodontal maintenance program and with the need for FMD participated in this study. Patients were randomly allocated to non-surgical periodontal therapy (NSPT) with either a preparatory 15-day decontamination phase, including chlorhexidine mouth rinse and domiciliary hygiene instructions (modified FMD: test group), or without it (FMD: control group). In both groups, NSPT was performed with the aid of a non-injectable anesthetic gel. Clinical and patient-related outcomes were recorded during a 6-month follow-up period. RESULTS: Sixty patients completed the 6-month study. Both groups experienced relevant clinical improvements after NSPT, but the test group showed a significant change in periodontal parameters already after the initial 15-day preparatory period, and overall significantly better results in periodontal outcomes when compared with the control group at the last 6-month follow up: the gingival index was 2.07 ± 1.25 in the control group and 1.13 ± 0.51 in the test group. Less pain and dental-related anxiety were perceived by patients in the test group showing a 6-month mean visual analog scale of 2.13 ± 1.25 in the control group and 1.13 ± 0.83 in the test group. CONCLUSION: The present study suggested that the modification of the standard FMD could improve the clinical efficacy of non-injectable anesthetic, along with patients' short- and mid-term appreciation and compliance

Impact of question order on prioritisation of outcomes in the development of a core outcome set: A randomised controlled trial

Background: Core outcome set (COS) developers increasingly employ Delphi surveys to elicit stakeholders' opinions of which outcomes to measure and report in trials of a particular condition or intervention. Research outside of Delphi surveys and COS development demonstrates that question order can affect response rates and lead to 'context effects', where prior questions determine an item's meaning and influence responses. This study examined the impact of question order within a Delphi survey for a COS for oesophageal cancer surgery. Methods: A randomised controlled trial was nested within the Delphi survey. Patients and health professionals were randomised to receive a survey including clinical and patient-reported outcomes (PROs), where the PRO section appeared first or last. Participants rated (1-9) the importance of 68 items for inclusion in a COS (ratings 7-9 considered 'essential'). Analyses considered the impact of question order on: (1) survey response rates; (2) participants' responses; and (3) items retained at end of the survey. Results: In total, 116 patients and 71 professionals returned completed surveys. Question order did not affect response rates among patients, but fewer professionals responded when clinical items appeared first (difference = 31.3%, 95% confidence interval [CI] = 13.6-48.9%, P = 0.001). Question order led to different context effects within patients and professionals. While patients rated clinical items highly, irrespective of question order, more PROs were rated essential when appearing last rather than first (difference = 23.7%, 95% CI = 10.5-40.8%). Among professionals, the greatest impact was on clinical items; a higher percentage rated essential when appearing last (difference = 11.6%, 95% CI = 0.0-23.3%). An interaction between question order and the percentage of PRO/clinical items rated essential was observed for patients (P = 0.025) but not professionals (P = 0.357). Items retained for further consideration at the end of the survey were dependent on question order, with discordant items (retained by one question order group only) observed in patients (18/68 [26%]) and professionals (20/68 [29%]). Conclusions: In the development of a COS, participants' ratings of potential outcomes within a Delphi survey depend on the context (order) in which the outcomes are asked, consequently impacting on the final COS. Initial piloting is recommended with consideration of the randomisation of items in the survey to reduce potential bias. Trial registration: The randomised controlled trial reported within this paper was nested within the development of a core outcome set to investigate processes in core outcome set development. Outcomes were not health-related and trial registration was not therefore applicable.</p

International experience and graduate employability: stakeholder perceptions on the connection

This paper reports the findings of an Australian qualitative study (N = 45) concerned with the way that employers, academics and students perceived connections between international experience and graduate employability. Drawing on the literature, the authors argue that increasing globalisation and internationalisation has heightened the need for graduates with the ability to operate in culturally diverse contexts. Universities have focussed upon exchange as part of internationalisation to prepare students for work but there is still limited literature on the nature of the relationship between international experience, more broadly and graduate employability. The findings suggest that all stakeholders identify clear connections between international experience and employability given outcomes associated with the forging of networks, opportunities for experiential learning, language acquisition and the development of soft skills related to cultural understandings, personal characteristics and ways of thinking.Joanna Elizabeth Crossman and Marilyn Clark