Introduction: Alveolar ridge preservation (ARP) is a well‐defined treatment performed to reduce bone dimensional changes occurring during the healing of post‐extraction sockets to allow for adequate implant placement. Leukocyte and platelet‐rich fibrin (L‐PRF) has been showing to potentially promote bone and tissue regeneration during wound healing. Therefore, the aim of this study is to evaluate its efficacy for ARP when applied to fresh extraction sockets, in comparison with spontaneous healing.Materials and Methods: Twenty‐seven patients with hopeless non‐molar teeth were treated. After randomization, fresh extraction sockets were either filled with L‐PRF or allowed to heal spontaneously. CBCTs and intraoral scans were obtained immediately after extraction and at 4 months. Through superimposition of the obtained images, changes in the horizontal ridge width, height, buccal volume, and ridge contour changes were measured, as well as patient‐reported outcome measures (PROM's).Results: The ridge dimensions changed similarly in both groups. Although less reduction occurred in the test group at 1 mm from the bone crest, differences were not statistically significant (p > 0.05). Application of L‐PRF did not prevent reductions of ridge contours, neither in the linear vertical aspect nor in volumetric changes. There were no differences between groups in the need for bone regeneration when placing implants. Patients in both groups reported similar outcomes in terms of bleeding, pain, inflammation, and function at 1 and 4 weeks postoperatively.Conclusion: Alveolar preservation with L‐PRF neither minimized bone resorption occurring after tooth extraction in non‐molar sites nor reduced the need for bone regeneration when placing implants. Furthermore, its use did not improve PROM's.

Objectives: This in vitro investigation was aimed to evaluate the cleaning ability of four mechanical devices designed for decontaminating implant surfaces.Material and methods: Ninety‐six implants were coated with permanent ink and inserted into 3D‐printed resin blocks simulating three different intraosseous defect configurations (types Ib, Ic, and Ie). The four tested mechanical decontamination devices (air‐polishing with glycine powder, rotating titanium brush, polyetheretherketone [PEEK]‐coated ultrasonic tip, and stainless steel ultrasonic tip) were randomly applied onto the 5 mm exposed implant surface. Standardized photographs were taken from a frontal perspective and with a 30° angle coronally and apically to the implant axis. The area with remnant ink on the implant surface was calculated.Results: Although none of the groups achieved complete ink removal, air‐polishing with glycine and titanium brushes demonstrated a higher cleaning ability when compared with ultrasonic devices either with standard or PEEK tips for all three defect configurations. For the three tested models, the best cleaning ability in all groups was shown on implant surfaces without facing an intraosseous wall. Titanium brush was the most effective when the intraosseous walls existed. Cleaning effectiveness diminished in the threads located in the apical third, especially when using air‐polishing and ultrasonic devices.Conclusions: Titanium brushes and air‐polishing devices were more effective in removing artificial biofilm using this in vitro model, although their effectiveness was influenced by the presence of the intrabony component.

Previous data show that the effects of clozapine on regional brain activity are different from those of other antipsychotic agents. It seemed of interest to study the brain activity patterns after treatment with clozapine, since this drug might correct basal deficits directly related to schizophrenia or instead induce changes that would in some way compensate distant abnormalities. In order to study the activity pattern resulting from clozapine treatment we have used FDG-PET and statistical parametric mapping (SPM) to explore the functional status of patients after chronic treatment with this drug, We compared their metabolic activity with normal controls and neuroleptic-naive (NN) patients, with the aim to identify if a reversion of pre-existing deficits or a induction of different changes was the result of clozapine administration. We compared metabolic patterns in 23 treatment-resistant (TR) patients after 6 months of treatment with clozapine, eighteen healthy subjects, and 17 NN schizophrenia patients. After treatment with clozapine, TR patients showed a clear hypofrontality and caudate hypometabolism in comparison with both the controls and NN patients, and also a lower thalamic activity than the healthy controls. In conclusion, our results support a preferential role for prefrontal regions and their subcortical connections in the mechanism of action of clozapine, resulting in a clearly hypofrontal state as compared to both controls and schizophrenia patients without previous treatment.

Objectives: Evaluate the dimensions and morphology of peri‐implant tissues around a modified dental implant designed with tissue level connection and a convergent transmucosal neck, when compared with a conventional bone level implant connected to a cylindrical machined titanium abutment.Material and methods: Eight experimental animals were used for this in vivo investigation, in whom 16 test and 16 control implants were placed following a random allocation sequence. The following histological outcomes at 4 and 12 weeks were evaluated: morphology of peri‐implant tissues, the soft tissue height and thickness, the horizontal and vertical bone remodeling, and the bone to implant contact (BIC).Results: In both early (4 weeks) and late (12 weeks) healing times, there were no statistically significant differences between test and control implants, with respect to the overall height and thickness of the peri‐implant hard and soft tissues. There was a tendency toward a more coronal free gingival margin (I‐FGM) at the buccal aspect of test when compared to control implants (at 4 weeks, difference of 0.97 mm (p = .572) and 0.30 mm (p = 1.000) at 12 weeks). Similarly, there was a tendency toward a more coronal position of the first bone to implant contact (I‐B) at the buccal aspect of test as compared to control implants (1.08 mm (p = 0.174) at 4 weeks and 0.83 mm (p = 0.724) at 12 weeks).Conclusions: Hard and soft tissue healing occurred at both implant types with no statistically significant differences. Test implants tended to present a more coronal gingival margin (FGM) and first bone to implant contact (B).