The working angle in low-abrasive air polishing has an influence on gingival damage-an ex vivo porcine model.

OBJECTIVES: To investigate the influence of instrumentation angle during low-abrasive air polishing (LAA) on the oral gingiva using an ex vivo porcine model. MATERIAL AND METHODS: Six tissue samples from each of 14 porcine mandibles were randomly selected and instrumented. Two different LAA powders (glycine 25 µm, tagatose 15 µm) were investigated. An application angle of either 30-60° or 90° was selected. Gingival specimens from different mandibles served as untreated references. Gingival biopsies were examined by scanning electron microscopy and paraffin histology for tissue destruction using a five-level scale. RESULTS: LAA caused significantly less tissue damage at a 90° angle than at a 30-60° angle. This effect was seen in both the glycine-based powder arms (p = 0.002, p = 0.046) and the tagatose-based powder arms (p = 0.003, p = 0.011). However, at identical working angles, the two powders did not show significant differences in terms of gingival erosion (p = 0.79 and p = 0.57; p = 0.91 and p = 0.78, respectively). CONCLUSIONS: LAA may cause less tissue damage at an application angle of 90°. Consequently, it seems advisable to air-polish the soft tissue as perpendicularly as possible. Additionally, glycine and tagatose LAA powders do not seem to differ in concern of soft tissue damage. CLINICAL RELEVANCE: Within the limitations of this ex vivo animal model, this study argues for an application that is as close as possible to the 90° angle intending to minimize soft tissue damage. Manufacturer specifications, however, mainly request applications deviating from the right angle. In order to work in interdental areas using LAA safely, the use of subgingival nozzles might be considered.

Apelin Enhances the Effects of Fusobacterium nucleatum on Periodontal Ligament Cells In Vitro.

This study aimed to explore effects of Fusobacterium nucleatum with or without apelin on periodontal ligament (PDL) cells to better understand pathomechanistic links between periodontitis and obesity. First, the actions of F. nucleatum on COX2, CCL2, and MMP1 expressions were assessed. Subsequently, PDL cells were incubated with F. nucleatum in the presence and absence of apelin to study the modulatory effects of this adipokine on molecules related to inflammation and hard and soft tissue turnover. Regulation of apelin and its receptor (APJ) by F. nucleatum was also studied. F. nucleatum resulted in elevated COX2, CCL2, and MMP1 expressions in a dose- and time-dependent manner. Combination of F. nucleatum and apelin led to the highest (p < 0.05) expression levels of COX2, CCL2, CXCL8, TNF-α, and MMP1 at 48 h. The effects of F. nucleatum and/or apelin on CCL2 and MMP1 were MEK1/2- and partially NF-κB-dependent. The combined effects of F. nucleatum and apelin on CCL2 and MMP1 were also observed at protein level. Moreover, F. nucleatum downregulated (p < 0.05) the apelin and APJ expressions. In conclusion, obesity could contribute to periodontitis through apelin. The local production of apelin/APJ in PDL cells also suggests a role of these molecules in the pathogenesis of periodontitis.

Interplay of pandemic and seasonal parameters in dental emergency service.

BACKGROUND: To evaluate the relationship between pandemic events and dental emergency service frequentation. Utilization patterns in the scope of the COVID-19 pandemic were analyzed and considered in regard of seasonal parameters. METHODS: All outpatients seeking treatment in a university hospital's dental emergency service were analyzed in the years 2019, 2019 and 2020 according to demographic data and emergencies were subdivided into "absolute" and "relative". The years 2018 and 2019 were used to compare COVID-19 and non-COVID-19 phases. Defined waves of the pandemic were compared with equivalent prior-year periods. RESULTS: Our study includes 11,219 dental emergency patients over a period of three years with a slight surplus of male patients. Comparing the pre-COVID-19 years and 2020 as a year of pandemic, the total count of cases decreased by more than 25%. The share of absolute emergencies in 2020 was higher than in the years before (p < 0.0001). The under-utilization during the waves was more pronounced during the first wave compared to the second waves. CONCLUSIONS: Additionally to the clear decrease by more than 25% in 2020, we found an inverse dependency of 7-day-incidence of COVID-19 and number of visits. This effect was more distinct for relative emergencies, while the number of patients with absolute emergencies remains rather constant. Probably, there is an acclimatization effect regarding the waves. Patients older than 60 years who suffered from relative emergencies showed an under-utilzation during 2020. During a pandemic such as COVID-19, the effect of under-utilization is more pronounced among elderly patients. However, a pandemic acclimatization effect seems to occur. This can be taken into account in the administration of this kind of circumstances in the future.