Peri-implantitis is an inflammatory disease affecting tissues surrounding dental implants. Although it represents a common complication of dental implant treatments, the underlying mechanisms have not yet been fully described. The aim of this study is to identify the role of titanium nanoparticles released form the implants on the chronic inflammation and bone lysis in the surrounding tissue. We analyzed the in vitro effect of titanium (Ti) particle exposure on mesenchymal stem cells (MSCs) and fibroblasts (FU), evaluating cell proliferation by MTT test and the generation of reactive oxygen species (ROS). Subsequently, in vivo analysis of peri-implant Ti particle distribution, histological, and molecular analyses were performed. Ti particles led to a time-dependent decrease in cell viability and increase in ROS production in both MSCs and FU. Tissue analyses revealed presence of oxidative stress, high extracellular and intracellular Ti levels and imbalanced bone turnover. High expression of ZFP467 and the presence of adipose-like tissue suggested dysregulation of the MSC population; alterations in vessel morphology were identified. The results suggest that Ti particles may induce the production of high ROS levels, recruiting abnormal quantity of neutrophils able to produce high level of metalloproteinase. This induces the degradation of collagen fibers. These events may influence MSC commitment, with an imbalance of bone regeneration.

Anxiety is a relevant problem in dental practice. The Visual Analogue Scale for Anxiety (VAS‐A), introduced in dentistry in 1988, has not yet been validated in large series. The aim of this study is to check VAS‐A effectiveness in more than 1000 patients submitted to implantology. The VAS‐A and the Dental Anxiety Scale (DAS) were administered preoperatively to 1114 patients (459 males and 655 females, age 54.7 ± 13.1 years). Statistical analysis was conducted with Pearson correlation coefficient, the receiver operating characteristic (ROC) curve, and McNemar tests. A close correlation between DAS and VAS‐A was found (r = 0.57, P < .0001); the VAS‐A thresholds of dental anxiety and phobia were 5.1 and 7.0 cm, respectively. Despite a significant concordance of tests in 800 cases (72%), disagreement was found in the remaining 314 cases (28%), and low DAS was associated with high VAS‐A (230 cases) or vice versa (84 cases). Our study confirms that VAS‐A is a simple, sensitive, fast, and reliable tool in dental anxiety assessment. The rate of disagreement between VAS‐A and DAS is probably due to different test sensitivities to different components of dental anxiety. VAS‐A can be used effectively in the assessment of dental patients, using the values of 5.1 cm and 7.0 cm as cutoff values for anxiety and phobia, respectively.

Melkersson–Rosenthal syndrome (MRS) is a rare, neuro-mucocutaneous disease which presents as orofacial swelling, facial palsy and fissured tongue. These symptoms may occur simultaneously or, more frequently, with a oligosymptomatic or monosymptomatic pattern. Swelling, that is the most common initial finding, may mimic hereditary or acquired angioedema, a disorder caused by histamine or bradykinin-mediated plasma-leakage affecting subcutaneous and/or submucosal tissue. The differential diagnosis of MRS includes also chronic inflammatory and infective diseases characterized by granulomatous infiltration, as well as rosacea, contact dermatitis, allergic reactions and Bell’s palsy. A 71-year old, non-allergic female patient with no familial and personal history of angioedema presented, a few days after a possible herpes simplex or varicella-zoster virus infection, with monolateral facial paraesthesia and lower lip edema. After temporary remission of symptoms on oral steroids and antihistamines, she showed swelling recurrence refractory to valaciclovir therapy and a subsequent course of antihistamines. The clinical picture and a previous history of non-Hodgkin lymphoma prompted us to rule out an acquired form of paraneoplastic, C1-inhibitor (C1-INH) deficiency: C1q and both antigen and functional C1-INH tested normal, whilst we found low plasma levels of C3 and C4 possibly related to the parallel detection of antiphospholipid antibodies. Thus, we hypothesized a non-histaminergic, idiopathic form of angioedema and planned further therapy with tranexamic acid and the leukotriene receptor antagonist montelukast. Treatment failure with both drugs finally suggested a Melkersson–Rosenthal syndrome, which was confirmed by histologic findings of non caseating granulomas on lip biopsy. Melkersson–Rosenthal syndrome may occur with rather non-specific symptoms and overlap with alternative conditions, including recurrent angioedema. No specific biomarkers for MRS exist and clinical diagnosis is often of exclusion. The finding of complement or immune alterations, as in our patient, may be further confounding and justify the need for skin or mucosal biopsy to establish a correct diagnosis and prescribe targeted therapy.