Clear and removable tooth aligners for orthodontics treatments have become an increasingly popular alternative to fixed appliances. Even if protocols suggest removing aligners before eating or drinking, most patients retain them when they drink beverages. Alterations in the material during the daily use could determine a reduction in the application forces, affecting the desired orthodontic movement; the knowledge of how this material reacts when subjected to different aging processes is mandatory to establish the predictability of the orthodontic treatment. According to this, the aim of the present study was to assess a new objective approach, coupling spectroscopic and chemometric tools, to evaluate the changes occurring in Invisalign^® aligners, the most widely used brand, exposed in vitro to coffee, tea, Coca Cola^® and UV radiation for 24 and 48 h. In particular, ATR-FTIR spectroscopy was utilized to characterize, at the molecular level, the chemical and color modifications in the surfaces of the appliances; the obtained data were submitted to PCA and one-way ANOVA and Tukey’s multiple comparison test. Moreover, a colorimetry analysis was carried out to evaluate any changes in color and transparency. Coffee and tea samples displayed the major color changes between the tested groups. The differences highlighted in the spectral features of coffee, tea and UV-treated samples were mainly ascribable to color and transparency changes, because the chemical properties remained unaltered.

Recently, the demineralized dentin matrix has been suggested as an alternative material to autologous bone grafts and xenografts for clinical purposes. The aim of this study was to investigate the effect of different times of demineralization on the chemical composition and the surface morphology of dentinal particles. Extracted teeth were ground and divided into 5 groups based on demineralization time (T0 = 0 min, T2 = 2 min, T5 = 5 min, T10 = 10 min, and T60 = 60 min) with 12% EDTA. The analysis was performed using Fourier-Transform Mid-Infrared spectroscopy (FT-MIR) and Scanning Electron Microscopy (SEM) (p < 0.05). The FT-MIR analysis showed a progressive reduction of the concentration of both PO₄³⁻ and CO₃²⁻ in the specimens (T0 > T2 > T5 > T10 > T60). On the contrary, the organic (protein) component did not undergo any change. The SEM examination showed that increasing the times of demineralization resulted in a smoother surface of the dentin particles and a higher number of dentinal tubules.

One of the current major challenges in implant therapy is to minimize marginal bone loss around implants, since it can trigger bacterial colonization of the implant’s neck, leading to its failure. The present study aimed (1) to scientifically validate a new mathematical rule based on soft tissues thickness, for choosing the correct implant position with respect to the bone level, in order to provide a better tissue adaptation to the abutment/implant surface to avoid bacterial invasion, and (2) to apply this mathematical rule to the Biological Oriented Immediate Loading (B.O.I.L.) surgical protocol, avoiding peri-implant bone resorption. N. 127 implants were inserted following B.O.I.L. protocol: implants were placed according to the mathematical rule Y = X − 3, which correlates the position of the implant from the bone crest level (Y) with the thickness of the soft tissues (X). All the implants were inserted in fresh extraction sockets, and immediately loaded with temporary abutments and prostheses. Bone levels were evaluated through radiographic examination just after surgical procedure (T0), and after 10 days (10D), 6 months (6M), 1 year (1Y), and 5 years (5Y). After 5 years, the implant survival rate was 100%, with a medium marginal bone loss around implants of 0.0704 mm (SD = 0.169 mm). One-way ANOVA, followed by Tukey’s multiple comparison test was performed for statistical evaluations (p < 0.05). This protocol provided a safe and successful procedure, with a good soft tissue seal against bacterial challenge. The application of the mathematical rule allows the implant placement in a correct vertical position from the bone crest, avoiding bone resorption and bacterial infiltrations. Moreover, the use of Multi Unit Abutment (MUA) determined a stable biological seal, favouring the implant healing and preserving the adhesion of hemidesmosomes to the titanium of MUA.

The aim of this study was to compare the epithelial biological response to machined titanium Ti-6Al-4V grade 5 and titanium Ti-6Al-4V grade 5 coated with zirconia (ZrN) by physical vapor deposition (PVD). Human keratinocytes were cultured in six-well plates. Machined titanium TiAl4V4 grade 5 (T1) and ZrN-coated titanium TiAl4V4 grade 5 (T2) discs were placed in two different wells. The remaining two wells served as control (C). Scanning electron microscopy (SEM) and energy-dispersive spectroscopy (EDS) were performed to compare the T1 and T2 surfaces. Subsequent analyses were performed to explore the effect of T1 and T2 contact with human keratinocyte HUKE cell lines. Cell viability was evaluated using a trypan blue exclusion test and MTT assay. Cell lysates from C, T1, and T2 were Western blotted to evaluate E-cadherin and Integrin-α6β4 expression. SEM revealed that T2 was smoother and more homogeneous than T1. EDS showed homogeneous and uniform distribution of ZrN coating on T2. Cell viability analyses did not show significant differences between T1 and T2. Furthermore, E-cadherin and Integrin-α6β4 expressions of the epithelial cells cultured in T1 and T2 were similar. Therefore, titanium Ti-6Al-4V grade 5 surfaces coated with ZrN by PVD seem to be similar substrates to the uncoated surfaces for keratinocyte adhesion and proliferation.

The use of xenogenic cortical bone laminas in Guided Bone Regeneration (GBR) has been well described in the literature over the past decade. These biomaterials present a very low degree of complications due to their nature (porcine or equine collagenated bone) and the fact that when they become exposed, they simply hydrolyze without major complications. One of the problems related to the first generation of these laminas was their extreme rigidity and return elasticity, often forcing clinicians to anchor them with pins and/or screws. A new generation of bone laminas called Flex Cortical Sheet (FCS) have recently been introduced with machine-made thicknesses of 0.2, 0.5, and 0.9 mm and increased flexibility and adaptability to ridge defects. This paper has the goal of presenting a case of vertical and horizontal reconstruction performed by means of a 0.5 mm FCS and showing the workflow necessary to successfully restore a complex situation. After 8 months of healing, the GBR resulted in a horizontal and vertical augmentation of 8 mm and 8 mm, respectively. The radiographic examination at 18 months demonstrated great stability of new bone around implants.

Several Alveolar Ridge Preservation (ARP) procedures have been proposed over the years. The purpose of this study was to describe the new Modified Periosteal Inhibition (MPI) technique for ARP. Seven patients were enrolled (age range: 28–72 years old; 5 males, 2 females). In total, nine hopeless teeth were treated. Following the elevation of a full-thickness flap, atraumatic tooth extraction was conducted, preserving the buccal bone of the alveolar socket. OsteoBiol^® Lamina Soft (Tecnoss^®, Giaveno, Italy), 0.5 mm thick, was suitably shaped (8–10 mm in height, extending from the mesial and to the distal corners of the socket). The lamina was gently positioned between the buccal periosteum and the buccal bone plate. Tisseel^® (Baxter Healthcare Corporation, Deerfield, IL, USA) was applied to seal the cortical membrane. The flaps were sutured with PTFE 4-0 (Omnia, Fidenza, Italy). Postoperative instructions were provided. Patients were strictly monitored during the follow-up. No early or late biological complications were experienced. Cone Beam Computed Tomography (CBCT) exams were performed at baseline and 4 months later. The thickness of the buccal cortical bone at baseline was 1.18 ± 0.57 mm. The pre-operative and post-operative ridge widths were 10.74 ± 1.54 mm and 11.16 ± 1.57 mm, respectively. A horizontal ridge increase of 0.41 ± 0.21 mm was observed during the healing period. At 4 months of healing, the bone volume was adequate for implant placement and no additional bone regeneration procedures were required. MPI technique was effective in preventing the horizontal contraction of the post-extraction socket. Further studies will be needed in the future to confirm our positive results.