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Background: Considerations about implant surface wear and metal particles released during implant placement have been reported. However, little is known about implant surface macro- and microstructural components, which can influence these events. The aim of this research was to investigate accurately the surface morphology and chemical composition of commercially available dental implants, by means of multivariate and multidimensional statistical analysis, in order to predict their effect on wear onset and particle release during implant placement. Methods: The implant surface characterization (roughness, texture) was carried out through Confocal Microscopy and SEM-EDS analysis, the quantitative surface quality variables (amplitude and hybrid roughness parameters) were statistically analyzed through post hoc Bonferroni’s test for pair comparisons. Results: The parameters used by discriminant analysis evidenced several differences in terms of implant surface roughness between the examined fixtures. In relation to the observed surface quality, some of the investigated implants showed the presence of residuals due to the industrial surface treatments. Conclusions: Many structural components of the dental implant surface can influence the wear onset and particles released during the implant placement.

When lower third molar inclusion is associated with neurosensorial complications, the treatment of choice is its surgical avulsion. One of these complications, that may be the most alarming during a first medical examination, is hemi-lip paraesthesia, that can appear in the presence of several mandibular lesions. This is a report of a rare clinical case in which paraesthesia was linked to the closeness between the root block of the dental element and the mandibular canal, which houses the neurovascular trunk of the lower mandibular nerve. A 64 year-old male Caucasian patient, presented with the chief complaint of past periodic inflammatory events in the retromolar region of the oral cavity and hemi-lip paraesthesia. Upon local clinical and radiological examination, a lower left third molar with class 3 position C inclusion was incriminated. The medical history of the patient revealed well compensated diabetes mellitus type II, and pharmacologically controlled hypertension. The tooth was surgically removed using piezoelectric instruments. Before and after surgery, three types of tests (tactile, pain and thermal sensitivity) were carried out to delimit the area affected by paraesthesia. At 7 days, the area of hypoesthesia of the hemi-lip was significantly reduced. Further improvement in tactile and thermal sensitivity occurred in subsequent follow-up, at 1 and 3 months, postoperatively. This clinical case demonstrates that the surgical intervention performed with piezoelectric instruments prevented the damage of an important structure such as the lower mandibular nerve, and promoted regression of a contingent paraesthesia.

Containment measures adopted to reduce the spread of coronavirus disease 2019 (COVID-19) have produced a general perception of job insecurity. Dentists have been highly affected by such measures, as they represent an easy source of contagion. As perceived job insecurity is associated with psychological distress and Italian dentists have been highly affected by the COVID-19 outbreak in terms of potential financial loss and the risk of being infected, this study aimed at assessing whether the fear of COVID-19 moderated the effect of perceived job insecurity on depressive symptoms. This cross-sectional online study has included 735 Italian dentists recruited during the lockdown and ranging in age from 27 to 70 years old (495 men and 240 women). A quantile regression model with an inference based on the median and with an interaction term between the fear of COVID-19 and perceived job insecurity has been used to estimate the hypothesized associations. The results indicated that both perceived job insecurity and fear of COVID-19 were positively associated with depressive symptoms, and that the effect of perceived job insecurity on depressive symptoms was weaker among those with a low fear of COVID-19. The findings may inform public health policies for dentists in relation to reducing the risk of developing negative mental health outcomes.