Different titanium surfaces modulate the bone phenotype of SaOS-2 osteoblast-like cells.

Commercially pure titanium implants presenting a relatively smooth, machined surface or a roughned endosseous surface show a large percentage of clinical successes. Surface properties of dental implants seem to be important with respect to bone cells response. Implant topography appears to modulate cell growth and differentiation of osteoblasts affecting the bone healing around the titanium implant. The aim of the present study was to examine the effects of three different titanium surfaces on cell morphology, adhesion and bone phenotypic expression of human osteoblast-like cells, SaOS-2. SaOS-2 cells were cultured on commercially pure titanium disks of 1 cm in diameter with three different surface roughness: smooth (S), sandblasted (SB) and titanium plasma sprayed (TPS). Differences in the cell morphology were found on the three surfaces showing an uniform monolayer of shaped cells on the S surfaces, and clusters of multilayered cells with an irregular shape on the rough surfaces. The adhesion of SaOS-2 cells, as measured after 3h of culture, was not affected by surface roughness. ECM components such as collagen I (CoI), fibronectin (FN), vitronectin (VN) and tenascin (TN) were secreted and organized only on SB and TPS surfaces while on S surfaces they remained in the cytoplasm. Osteopontin and BSP-II were largely detected on SB and TPS surfaces, while only minimal production was observed on S surfaces. These data show that titanium surface roughness affects bone differentiation of osteoblast like-cells, SaOS-2, indicating that surface properties may be able to modulate the osteoblast phenotype. These observations also suggest that the bone healing response around dental implants can be affected by surface topography

Soft tissue regeneration using leukocyte-platelet rich fibrin after exeresis of hyperplastic gingival lesions: Two case reports

Introduction The Leukocyte-PRF (Leukocyte-Platelet Rich Fibrin) belongs to a second generation of platelet concentrates which doesn’t need a biochemical blood manipulation. It is used for tissue healing and regeneration in periodontal and oral-maxillofacial surgery. We report two cases of hyperplastic gingival lesions treated by exeresis and application of PRF membranes in order to improve and accelerate tissue healing. Case Presentation Two patients (one Caucasian female, 78-year-old, and one Caucasian male, 30-year-old) were treated for hyperplastic gingival lesions. They underwent to exeresis of lesions and application of PRF membranes. Tissue healing was clinically evaluated after one, three, seven, fourteen and thirty post-operative days. No recurrences were observed after two years of semiannual follow up. Conclusion We obtained rapid and good healing of soft tissues probably due to the elevated content of leukocytes, platelets and growth factors in the leukocyte-platelet rich fibrin. According to our results we suggest L-PRF employment for wounds covering after exeresis of oral neoformations such as hyperplastic gingival lesions

Perceived Job Insecurity and Depressive Symptoms Among Italian Dentists: The Moderating Role of Fear of COVID-19

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

Effect of biologically oriented preparation technique on the stress concentration of endodontically treated upper central incisor restored with zirconia crown: 3d-fea

The aim of this study was to evaluate the effect of biologically oriented preparation technique on the stress concentration of endodontically treated upper central incisors restored with zirconia crown (yttria-stabilized zirconia polycrystalline ceramic) through finite element analysis (FEA). Four models of maxillary central incisors containing enamel, dentin, periodontal ligament, cortical and medullary bone were created in CAD. Each model received a polymeric core-build up with nanofilled dental resin composite. The evaluated models were SM—preparation in shoulder 90°; CM—chamfer preparation; BOPT—biologically oriented preparation technique and BOPTB—BOPT preparation 1 mm below the cement-enamel junction. All models received zirconia crowns (5Y-TZP), fiberglass post and 1 mm ferrule. The models were imported into the analysis software with parameters for mechanical structural testing using the maximum principal stress and the tensile strength as the analysis criteria. Then, load of 150 N was applied at the cingulum with 45° slope to the long axis of the tooth, with the fixed base for each model. The type of marginal preparation affected the stresses concentration in endodontically treated teeth and in the zirconia crown margin. Considering the stress magnitude only, BOPT is a viable option for anterior monolithic zirconia crowns; however, with the highest stress magnitude at the restoration margin