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Bone resorption in edentulous regions often results in inadequate ridge for implant osseointegration. In order to overcome this problem, the use of osteoconductive biomaterials has been proposed as a carrier for different types of pharmacological molecules. Since raloxifene, a drug used in osteoporosis therapy, inhibits the osteoclast, but not osteoblast functions, it has been suggested to improve recovery during implant surgery. The present work evaluated in vitro the effect of raloxifene on two different cell populations: the human osteoblast-like cells (MG63) and osteoblasts derived from rat calvaria (MC3T3-E1). The morpho-functional investigations carried out showed a different behavior of the two cell lines. Raloxifene showed a stimulatory effect towards MG63 cell proliferation with a significant increase in cell viability after 7 days of culture. On the contrary, MC3T3-E1 cells showed a significant reduction in cell viability, when compared with the same cells at 72 h, or with the control cell population. The predominantly proliferative effect of raloxifene on MG63 cells is partly confirmed by the reduction of alkaline phosphatase activity, an early marker of osteoblast differentiation. The different effect of raloxifene on osteoblastic population in relationship to the type and age of the cell is an issue that needs further investigation.

The mucosa around implants and the gingiva around teeth respond to plaque formation with the development of an inflammatory lesion which has similar magnitude and histological features. Different cell types in inflamed and healthy periodontal and peri-implant tissues are capable of producing a variety of important pro-inflammatory and anti-inflammatory cytokines and growth factors which mediate the host response. The aim of this study is to compare the expression levels of anti-inflammatory cytokines detectable in the peri-implant soft tissue of two single-implant crowns supported either by zirconia or titanium abutments. Two frozen samples of peri-implant soft tissue of two single-implant crowns supported either by zirconia or titanium abutments were treated to obtain mRNA. The mRNA extracted from these specimens was converted in cDNA and analyzed with “SuperArray GEArray Q Series Human Inflammatory Cytokine/Receptor Gene Array kit”, planned for studying 96 genes involved in inflammatory response. Data showed that gene expression levels of anti-inflammatory cytokines were higher in specimens sampled from the zirconia abutment compared with those from the titanium abutment. It was considered important to detect the mRNA levels of the anti-inflammatory mediators in healthy peri-implant tissues to verify the biological tolerability of zirconia compared with titanium abutments. The difference detected in cytokine expression could be due to the intrinsic biological tolerability of zirconia ceramics or to a lesser bacterial accumulation.

The ocean's biological carbon pump plays a major role in climate and biogeochemical cycles. Photosynthesis at the surface produces particles that are exported to the deep ocean by gravity. Sediment traps, which measure deep-carbon fluxes, help to quantify the carbon stored by this process. However, it is challenging to precisely identify the surface origin of particles trapped thousands of meters deep due to the influence of ocean circulation on the sinking path of carbon. In this study, we conducted a series of numerical Lagrangian experiments in the Porcupine Abyssal Plain region of the North Atlantic and developed a machine learning approach to predict the surface origin of particles trapped in a deep-ocean sediment trap. Our numerical experiments support the predictive performance of the machine learning approach, and surface conditions appear to provide valuable information for accurately predicting the source area, suggesting a potential application with satellite data. We also identify factors that potentially affect prediction efficiency, and we show that the best predictions are associated with low kinetic energy and the presence of mesoscale eddies above the trap. This new tool could provide a better link between satellite-derived sea surface observations and deep-ocean sediment trap measurements, ultimately improving our understanding of the biological-carbon-pump mechanism.

Through the constant rain of sinking marine particles in the ocean, carbon (C) trapped within is exported into the water column and sequestered when reaching depths below the mesopelagic zone. Atmospheric CO2 levels are thereby strongly related to the magnitude of carbon export fluxes in the mesopelagic zone. Sinking particles represent the main source of carbon and energy for mesopelagic organisms, attenuating the C export flux along the water column. Attempts to quantify the amount of C exported versus C consumed by heterotrophic organisms have increased in recent decades. Yet, most of the conducted estimations have led to estimated C demands several times higher than the measured C export fluxes. The choice of parameters such as growth efficiencies or various conversion factors is known to greatly impact the resulting C budget. In parallel, field or experimental data are sorely lacking to obtain accurate values of these crucial overlooked parameters. In this study, we identify the most influential of these parameters and perform inversion of a mechanistic model. Further, we determine the optimal parameter values as the ones that best explain the observed prokaryotic respiration, prokaryotic production and zooplankton respiration. The consistency of the resulting C budget suggests that such budgets can be adequately balanced when using appropriate parameters.

Radium-228 (228Ra), an almost conservative trace isotope in the ocean, supplied from the continental shelves and removed by a known radioactive decay (T1∕2 = 5. 75 years), can be used as a proxy to constrain shelf fluxes of other trace elements, such as nutrients, iron, or rare earth elements. In this study, we perform inverse modeling of a global 228Ra dataset (including GEOSECS, TTO and GEOTRACES programs, and, for the first time, data from the Arctic and around the Kerguelen Islands) to compute the total 228Ra fluxes toward the ocean, using the ocean circulation obtained from the NEMO 3.6 model with a 2° resolution. We optimized the inverse calculation (source regions, cost function) and find a global estimate of the 228Ra fluxes of 8.01–8. 49 × 1023 atoms yr−1, more precise and around 20 % lower than previous estimates. The largest fluxes are in the western North Atlantic, the western Pacific and the Indian Ocean, with roughly two-thirds in the Indo-Pacific Basin. An estimate in the Arctic Ocean is provided for the first time (0.43–0.50 × 1023 atoms yr−1). Local misfits between model and data in the Arctic, the Gulf Stream and the Kuroshio regions could result from flaws of the ocean circulation in these regions (resolution, atmospheric forcing). As radium is enriched in groundwater, a large part of the 228Ra shelf sources comes from submarine groundwater discharge (SGD), a major but poorly known pathway for terrestrial mineral elements, including nutrients, to the ocean. In contrast to the 228Ra budget, the global estimate of SGD is rather unconstrained, between 1.3 and 14. 7 × 1013 m3 yr−1, due to high uncertainties on the other sources of 228Ra, especially diffusion from continental shelf sediments. Better precision on SGD cannot be reached by inverse modeling until a proper way to separate the contributions of SGD and diffusive release from sediments at a global scale is found.

The northeast Atlantic is a key horizontal and vertical crossroads region for the meridional overturning circulation, but basic nutrient and oxygen fluxes are still poorly constrained by observations in the region. A surface to bottom northeast Atlantic Ocean budget for mass, nutrients (nitrate and phosphate) and oxygen is determined using an optimization method based on three surveys of the OVIDE transect (from Greenland to Portugal) completed with the World Ocean Atlas 2009. Budgets are derived for two communicating boxes representing the northeastern European basin (NEEB) and the Irminger Sea. For the NEEB (Irminger) box, it is found that 30% of the mass import (export) across the OVIDE section reach (originate from) the Nordic Seas, while 70% are redistributed between both boxes through the Reykjanes Ridge (9.3 ± 0.7 × 109 kg s−1). Net biological source/sink terms of nitrate point to both the Irminger and NEEB boxes as net organic matter production sites (consuming nitrate at a rate of –7.8 ± 6.5 kmol s−1 and –8.4 ± 6.6 kmol s−1, respectively). Using a standard Redfield ratio of C : N = 106 : 16, nitrate consumption rates indicate that about 40 TgC yr−1 of carbon is fixed by organic matter production between the OVIDE transect and the Greenland–Scotland Ridge. Nutrient fluxes also induce a net biological production of oxygen of 73 ± 60 kmol s−1 and 79 ± 62 kmol s−1 in the Irminger and NEEB boxes, which points to the region as being autotrophic. The abiotic air–sea oxygen flux leads to an oceanic oxygen uptake in the two regions (264 ± 66 kmol s−1 in the north and 443 ± 70 kmol s−1 in the south). The abiotic flux is partitioned into a mixing and a thermal component. It is found that the Irminger Sea oceanic oxygen uptake is driven by an air–sea heat flux cooling increasing the ocean surface oxygen solubility. Over the northeastern European basin the mixing component is about half the thermal flux, presumably because of the oxygen minimum in the subtropical thermocline.

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Background and Objectives : This study aimed to evaluate the outcomes of Class II subdivision teenage patients treated with Invisalign ® clear aligners (CAs) and elastics. Materials and Methods : A total of 23 individuals aged 14.3 ± 2.5 years were enrolled in this study. The participants were divided into Group 1 (mandibular midline deviation) and Group 2 (maxillary midline deviation). The midline deviation from the facial midline; anteroposterior discrepancy; overjet (OJ), overbite (OB), and Peer Assessment Rating (PAR) scores; upper incisor and lower incisor (L1) positions; and angulation were measured at the beginning (T0) and end (T1) of the orthodontic treatment. Results : Group 1 showed significant higher variations in OJ (-2.3 ± 2.3 vs. -0.6 ± 0.8, p < 0.001), OB (-2.1 ± 2.3 vs. -1.1 ± 1.4, p < 0.001), PAR score (-32.0 ± 11.7 vs. -27.3 ± 13.1, p < 0.001), L1-to-mandibular-plane angle (-3.6 ± 7.0 vs. -1.3 ± 3.2, p < 0.001), and interincisal angle (10.07 ± 8.7 vs. 5.9 ± 5.3, p = 0.007). The midline deviation was the only measurement with higher variation in Group 2. The average distance between the mesiobuccal cusp of the maxillary first molar and the buccal groove of the mandibular first molar was 0.3 ± 0.5 mm. Conclusions : A total of 21 patients achieved bilateral Class I (91% success rate) and demonstrated great improvement (72-96%) in PAR scores. Regardless of the etiology of malocclusion, the orthodontic correction of the Class II subdivision with CAs showed high accuracy and predictable results.

Background: In daily surgical practice, the dentist deals with various types of oral surgery. At the first visit, the patient fills out a questionnaire about their state of health. If the questionnaire does not reveal any particular hematological problems, no special tests are usually required to determine the platelet count. The aim of this prospective study was to evaluate the healing process of patients and its correlation with platelet levels before surgery., Methods: A total of 50 patients were included in whom blood chemistry tests were performed with special attention to the platelet count and before their mandibular eights were extracted .The type of healing (EHI) and pain on the second day (VAS) were assessed using methods validated in the literature., Results: After the EHI and VAS scores were noted in the medical records, envelopes containing the platelet scores of the previously requested blood samples, which were not read at the time of observation, were opened. An increase in EHI scores and a decrease in VAS scores was observed that were statistically significantly correlated with increasing platelet scores., Conclusions: These results suggest that the dentist should request chemistry tests on preoperative blood, especially if the patient is to undergo a particularly demanding oral surgical procedure, such as implants, guided bone regeneration or complex extractions.

The infraocclusion (IO) of primary molars, often seen in retained deciduous teeth, is a common condition that presents significant challenges for pediatric oral health. It occurs when primary molars are positioned below the occlusal plane due to the absence of permanent successors, leading to complications such as misaligned teeth, impaired chewing, and long-term dental health issues., Objectives: This study examines IO prevalence, diagnosis, and treatment approaches., Methods: A systematic review following PRISMA guidelines was conducted, searching PubMed, Web of Science, and Scopus for articles from the last 15 years. Nine articles were included for qualitative analysis., Results: IO was associated with several complications, including root resorption, altered eruption of adjacent teeth, and space loss within the dental arch. Clinical and radiographic evaluations are key to early detection. Severe cases often require invasive treatments, such as tooth extraction and space maintenance, while mild cases could be monitored., Conclusions: IO is prevalent in pediatric dentistry and can lead to significant dental issues if untreated. Early detection and intervention are crucial for preventing complications like tooth misalignment and impacted premolars. Tailored treatment strategies based on severity, along with increased awareness among dental practitioners, are essential to improve long-term outcomes for affected children.

Drilling for implant site preparation generates heat, which can cause bone necrosis if temperatures exceed 47 °C for over a minute. Factors influencing heat include drill size, speed, pressure, irrigation, and tool wear. Frequent drill replacement is essential, as wear from repeated use and sterilization affects performance. This study compared three pilot drills with similar designs from different manufacturers, testing each on pig ribs for 15 perforations after 15 sterilization cycles. Researchers measured temperature increase, drilling time, and surface wear. Results showed that drill no. 1 generated more heat than drills no. 2 and no. 3, though none reached critical temperatures. Drill no. 2 took the longest to reach the desired depth and displayed the most deformation. Findings highlight the importance of adhering to the recommended operational limits, suggesting that drills should be replaced after 15 cycles to ensure efficacy and patient safety.

Background: The proper development of the dental arches, including the eruption and correct positioning of the canines in the arch, is essential for the oral health of growing patients. Impacted canines not only give rise to functional challenges but also pose esthetic issues for patients. The aim of this article is to show if it is possible to benefit from the exclusive use of transparent aligners to guide the eruption of ectopic upper canines into the arch in the correct position., Case Report: The subject of the study is the clinical case of a 13-year-old female growing patient who presented displaced upper permanent canines located in the palatal ectopic site. Following the surgical extraction of the retained deciduous elements, treatment with aligners for repositioning the ectopic canines in the arch was performed in two phases. At the end of the treatment, a Class I canine was achieved with satisfactory repositioning of the upper canines in the arch., Conclusion: The use of transparent aligners makes it possible, with some procedural precautions and in carefully selected cases, to reposition the ectopic palatal canines in the dental arch using a treatment that is both esthetic and effective.

Psoriatic arthritis is defined as chronic inflammatory arthritis associated with psoriasis. The current data regarding gender differences in clinical manifestation and therapeutic outcomes of psoriatic arthritis are limited. Generally, men show a peripheral disease manifestation, while women have an axial distribution of the lesions. If we look at temporomandibular joint (TMJ) involvement, epidemiological data on the involvement of the TMJ are hard to find. Few studies on therapeutic management and the related impact on the quality of life are reported in the literature. Given the morpho-functional peculiarities of the TMJ and the different pain burdens between male and female genders, when manifestation of psoriatic arthritis occurs, clinicians should face it using a multidisciplinary approach for a correct diagnosis and successful treatment. This review aims to examine the diagnostic signs of psoriatic arthritis in the TMJ, the eventual variations of this disease in male and female patients, and the therapeutical strategies. The coordination of different specialties is fundamental to the remission of clinical symptoms and lesion regression.

Background and Objectives : The use of biomaterials in dentistry is extremely common. From a commercial perspective, different types of osteoconductive and osteoinductive biomaterials are available to clinicians. In the field of osteoconductive materials, clinicians have biomaterials made of heterologous bones at their disposal, including biomaterials of bovine, porcine, and equine origins, and biomaterials of natural origin, such as corals and hydroxyapatites. In recent years, it has become possible to synthesize nano-Ha and produce scaffolds using digital information. Although a large variety of biomaterials has been produced, there is no scientific evidence that proves their absolute indispensability in terms of the preservation of postextraction sites or in the execution of guided bone regeneration. While there is no scientific evidence showing that one material is better than another, there is evidence suggesting that several products have better in situ permanence. This article describes a preliminary study to evaluate the histological results , ISQ values, and prevalence of nano-HA. Materials and Methods : In this study, we planned to use a new biomaterial based on nanohydroxyapatite for implantation at one postextraction site; the nano-HA in this study was NuvaBONE (Overmed, Buccinasco, Milano, Italy). This is a synthetic bone graft substitute that is based on nanostructured biomimetic hydroxyapatite for application in oral-maxillofacial surgery, orthopedics, traumatology, spine surgery, and neurosurgery. In our pilot case, a patient with a hopeless tooth underwent extraction, and the large defect remaining after the removal of the tooth was filled with nano-HA to restore the volume. Twelve months later, the patient was booked for implant surgery to replace the missing tooth. At the time of the surgery, a biopsy of the regenerated tissue was taken using a trephine of 4 mm in the inner side and 8 mm deep. Results : The histological results of the biopsy showed abundant bone formation, high values of ISQ increasing from the insertion to the prosthetic phase, and a good reorganization of hydroxyapatite granules during resorption. The implant is in good function, and the replaced tooth shows good esthetics. Conclusions : The good results of this pilot case indicate starting the next Multicentric study to have more and clearer information about this nanohydroxyapatite (NH) compared with control sites.

Background: The long-term success of implant therapy depends not only on proper osseointegration, but also on the healing of the epithelium and the quality of the biological seal on the abutment and on the implant neck. This study aims to evaluate the possible use of dentinal adhesives on the surface of the transmucosal path of dental implants in order to create a hermetic seal between keratinized epithelium and abutment., Methods: Four sections of 12 µm thickness were obtained from a sample of the oral mucosa. Scotchbond TM Universal Adhesive (3M ESPE, Seefeld, Germany) was carefully applied both to the samples and to the transmucosal path of titanium abutment (Win-Six, BioSAFin, Italy). The adhesives were polymerized. FT-IR analysis was performed on: 1) polymerized Scotchbond Universal Adhesive (3M ESPE, Seefeld, Germany); 2) the interface between the titanium abutment and the adhesive; 3) the interface between the adhesive and the mucosa; 4) the mucosa samples., Results: Comparing the spectra, it emerged that the adhesive has established chemical bonds both on titanium and on the keratinized mucosa, involving different types of chemical interactions., Conclusions: The results of this in-vitro study are encouraging. In the future biocompatibility and comparative study with other adhesives will be required.

Subperiosteal implants were introduced in the last century. Poor clinical results led those implants to be progressively abandoned. Recently, several Authors suggested a revival of subperiosteal implants as an alternative to regenerative procedures. The purpose of this study was to describe the clinical application of custom-made additively manufactured subperiosteal implant for fixed prosthetic rehabilitation of edentulous maxilla. Plaster models of the upper and the lower arch were scanned, as well as the mock-up. Digital Imaging and Communications in Medicine data obtained from cone beam computed tomography were processed through the thresholding procedure. The design of the subperiosteal implant was drawn on the stereolithographic model and scanned. Once the digital project of the subperiosteal implant was completed, it was sent to additive manufacturing. After the surgery, the patient was strictly monitored for up to 2 years. The outcomes were assessed based on the incurrence of biological and mechanical complications, postoperative complications, and implant survival. The patient did not suffer from postoperative complications. Neither biological nor mechanical complications occurred during the follow-up period. At the end of the study, the implant was still in function. Custom-made subperiosteal implants could be considered as an alternative to regenerative procedures for the rehabilitation of severe bone atrophy. Further studies are needed in the future to confirm the positive outcome.

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., Competing Interests: The authors declare no conflict of interest.

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.

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.

Objectives: Fourier Transform Infrared microspectroscopy let characterize the macromolecular composition and distribution of tissues and cells, by studying the interaction between infrared radiation and matter. Therefore, we hypothesize to exploit this analytical tool in the analysis of inflamed pulps, to detect the different biochemical features related to various degrees of inflammation., Materials and Methods: IR maps of 13 irreversible and 12 hyperplastic pulpitis, together with 10 normal pulps, were acquired, compared with histological findings and submitted to multivariate (HCA, PCA, SIMCA) and statistical (one-way ANOVA) analysis. The fit of convoluted bands let calculate meaningful band area ratios (means ± s.d., P < 0.05)., Results: The infrared imaging analysis pin-pointed higher amounts of water and lower quantities of type I collagen in all inflamed pulps. Specific vibrational markers were defined for irreversible pulpitis (Lipids/Total Biomass, PhII/Total Biomass, CH 2 /CH 3 , and Ty/AII) and hyperplastic ones (OH/Total Biomass, Collagen/Total Biomass, and CH 3 Collagen/Total Biomass)., Conclusion: The study confirmed that FTIR microspectroscopy let discriminate tissues' biological features. The infrared imaging analysis evidenced, in inflamed pulps, alterations in tissues' structure and composition. Changes in lipid metabolism, increasing amounts of tyrosine, and the occurrence of phosphorylative processes were highlighted in irreversible pulpitis, while high amounts of water and low quantities of type I collagen were detected in hyperplastic samples., (© 2017 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.)

In 1979, Pulsed electromagnetic fields (PEMFs) were approved by the Food and Drug Administration as an effective method in the treatment of non-unions. As well as PEMFs, also static magnetic fields (SMFs) have been widely investigated in orthopaedic studies. Even if the exact mechanism of action is not well understood, a large number of studies showed specific effects both at cellular and tissue levels. As bone fracture healing and osseointegration share the same biological events, the application of magnetic field stimulation in order to facilitate the osseointegration process has been suggested. In this study we investigated BIC and newly formed bone volume around dental implants inserted in the tibia of New Zealand rabbits after SMF stimulation, generated by a small-customized cover-screw-shaped neodymium-iron-bore magnet placed in the inner cavity of dental implants. As a result, we found that the SMF field generated around dental implants enhanced bone healing in the animal model. Our findings represent, to our knowledge, the first ready clinical technique for dental implants showing the ability of SMF to promote the osteogenesis process in vivo.

Since 1979, Pulsed electromagnetic fields (PEMFs) have been approved by the Food and Drug Administration as an effective method in the treatment of non-unions. As well as PEMFs, also static magnetic fields (SMFs) have been widely investigated in orthopaedic studies. Even if the exact mechanism of action is not well understood, a large number of studies showed specific effects both at cellular and tissue levels. As bone fracture healing and osseointegration share the same biological events, the application of magnetic field stimulation in order to facilitate the osseointegration process has been suggested. In this study we investigated the proliferation rate and gene expression profile of MG63 osteoblastic-like cells after a 24, 48 and 72-hour SMF stimulation, generated by a small, customized cover screw-shaped neodymium-iron-bore magnet placed in the inner cavity of a dental implant. As a result, we found that the application of a SMF to osteoblastic-like cells does slightly decrease cell proliferation rate while enhancing the expression of those genes correlated to differentiation and mineralization. Our findings represent, to our knowledge, the first clinical ready technique for dental implants showing the ability of SMF to promote the osteogenesis process in vitro.

Calcium phosphate ceramics have been applied in bone replacement for several decades due to their excellent biocompatibility, bioactivity, osteo-conductivity and mechanical strength. Several studies have demonstrated that porous hydroxyapatite (HA) is an excellent scaffold for osteogenic proliferation and differentiation of the osteoprogenitor cells. However, different methods of synthesis and production of HA ceramic-based materials may have considerable effect on the physical and biological properties. In the present work, two hydroxyapatite-based materials, a natural hydroxyapatite ceramic of bovine origin and a synthetic nano-cristalline hydroxyapatite were tested in vitro with MG63 cell line. The results displayed that both the materials demonstrated a good biocompatibility. The immunocytochemical stain revealed a different positivity of the osteogenic markers between the cultures with the biomaterials, and the control culture. Western blot data confirmed the immunocytochemical stain. Both the materials tested in the present study demonstrated a good biocompatibility with the osteoblastic cells allowing, at the same time, the osteogenic differentiation, and they may be useful in clinical use.

Since Raloxifene, a drug used in osteoporosis therapy, inhibits the osteoclast functions but not osteoblast functions, it could improve the recovery during implant surgery. This preliminary report describes a simple method to link, through a covalent bond, Raloxifene to titanium by interfacing with (3-aminopropyl)-Triethoxysilane as assessed by the IR-FT and SEM. To evaluate the biological response of osteoblast-like cells to this implant, we compared expression gene profiling of cell cultures on Raloxifene conjugated implant and normal implant by DNA microarray. By using DNA microarrays containing 19,200 genes, we identified differently expressed genes in osteoblast-like cell line (MG-63). Surface Raloxifene conjugated implants have been shown to have a relevant importance in modifying cell response. This result could be an interesting starting point for the use of an immediate functional loading of implants.

Implant impression and transfer of the implant position to a working cast for rehabilitative purposes not always represent a predictable reconstructive step. The variable results depend on the transfer technique utilized and on the accuracy of the impression materials. The aim of this study was to compare the accuracy of the direct and indirect impression techniques and to analyze the distortion of different impression materials. An edentulous acrylic resin mandible was used as reference model: in the cuspid position 2 laboratory analogs were inserted perpendicularly to the occlusal plane and fastened with resin. Two impressions for each indirect and direct recording techniques with 4 different impression materials were made. Polyvinyl siloxanes were used for the repositioning implant level method. Polyethers were used for the ''pick up'' impression technique. Analysis of cast distortion was measured computing the inter-implant position on the developed models compared to that of the master model. Measurements were recorded by a digital caliper. The results of this in vitro study demonstrate that the direct impression technique is preferable to the indirect one and that the Impregum polyether impression material is the most precise when used in association with a direct technique.

Aim: The implant/abutment interface represents a crucial element to maintain the structural stability of the implant restoration and to prevent mechanical problems that can compromise the long-term success of the implant treatment., Methods: In this study deformation of the external hexagonal and internal octagonal extension of 2 implants after applying different values of insertion torque has been tested. The implants were secured in a customized resin baseplate, with the implant neck exposed, then different values of insertion torque were applied by an electronic torque controller., Results: Five internal octagonal implants were tested for 60 seconds to different torque magnitudes (12 Ncm, 21 Ncm, 27 Ncm, 36 Ncm, 42 Ncm). Two external hexagonal implants were tested for 60 seconds to a torque value of 27 Ncm and of 36 Ncm., Conclusions: After torquing tests, each implant was examined by a scanning electron microscope (SEM) medium and high magnification to evaluate the deformation of the 2 different antirotational systems. The SEM analysis of the internal octagonal and external hexagonal antirotational systems of the TBR implant showed a deformation proportional to the magnitude of the applied torque during implant insertion. The geometric deformation of the antirotational extension is capable of compromising its function after a torque magnitude of 36 Ncm or superior to this value. Moreover it was demonstrated a more evident alteration of the external hexagonal extension in comparison with the octagonal system after applying a torque value of 27 Ncm.

Background: The insertional region of the Achilles tendon includes: the fibrocartilage of the enthesis at the tendon-bone junction, the sesamoid fibrocartilage in the deep surface of the tendon, and the periosteal fibrocartilage covering the superior tuberosity of the calcaneus. The mechanism by which compressive stress and low oxygen concentration modulate the phenotypical expression of cartilaginous cells in mesenchymal tissue is still unknown. Tenascin-C isoform, with its anti-adhesive properties, has been hypothesized to have a role in cellular adaptation to compression. The purpose of this study was to define the immunohistochemical localization of tenascin-C in the enthesis organ of the Achilles insertion in man., Methods: Five specimens of Achilles tendon and its insertion were obtained from adult patients during below-knee amputation surgery. To determine the histochemistry, for light microscopy, specimens were stained with hematoxylin-eosin, safranin-O, Verhoeff, alcian blue methods. For immunohistochemistry, the following antibodies were used: anti-S-100 protein; anti-chondroitin sulfate; anti-types I and II collagen, anti-type IV collagen, anti-type X collagen, and anti-tenascin-C., Results: The enthesis, sesamoid, and periosteal fibrocartilages have been defined by a separate region of immunohistochemical labeling for S-100 antibody and type II collagen and chondroitin-sulfate. The sesamoid and periosteal fibrocartilages stained for tenascin-C, which in cartilaginous areas was closely associated with rounded cells in the extracellular matrix., Conclusion: By showing a relationship between chondrocyte-like cells and immunolabeling for tenascin-C in periosteal and sesamoid fibrocartilage, the present data suggest a role in the dynamic equilibrium in the formation of fibrocartilaginous foci in tendon areas exposed to compressive stress., Clinical Relevance: The data support the surgical practice of the resection of the diseased tendinous portion in case of chronic Achilles tendinitis. The decompression removed the enthesis organ that in an inflammatory environment could be altered and would not contribute to the distribution of the tensive load. After the decompression, it was hypothesized that in tendon areas exposed to compressive stress there was restoration of the fibrocartilaginous foci that constitute the enthesis organ.

Purpose: Several recent medical reports have focused attention on the possible application of skeletal scintigraphy imaging in odontostomatology. The aim of the present report was to assess the influence of immediate prosthetic loading on peri-implant osteoblastic activity through bone scintigraphy., Materials and Methods: Implants were placed in 2 healthy women. A nuclear medicine investigation with single-photon emission-computed tomography (SPECT) was performed for both patients at 30 and 90 days after implant placement. The study was completed with acquisitions of planar images of the skull in an anterior view and the use of regions of interest (ROIs) of the same size in the area corresponding to immediate loading and in the opposite hemimandible (at the control sites). Count density ratios (counts/pixel) obtained from each ROI were used for a quantitative/relative assessment. Tomographic images were evaluated with a qualitative method. The spatial resolution of the reconstructed tomograms and of the planar images was approximately 7 mm., Results: Routine planar methodology provided a direct measure of cellular activity of the examined areas. The difference in count density ratio registered from the same ROI between the first and the second scintigraphy revealed the course of peri-implant osteoblastic activity, which was very high in the first month and then declined during subsequent months., Discussion and Conclusion: In spite of the small number of involved patients, the results obtained from this pilot study suggest that nuclear medicine may hold possible advantages in implant dentistry for those who seek to clarify the still unknown aspects of osteoblastic activity.

Biphosphonates are a large class of drugs which inhibits the resorbing activity of osteoclasts. The aim of this study was to evaluate the influence of topical application of the biphosphonate alendronate on the integration process of endosseus implants placed in a partially edentulous patient. After incision and elevation of a mucoperiosteal flap and carrying out the osteotomy, 2 SLA implants 10 mm long and 3.5 mm wide were inserted in the area of # 4.5 and 4.6. Before placement of # 4.5, a paste made of grinded tablets of alendronate and Rifocin was applied in the osteotomy. Fifteen days after stage I, an evaluation of the osteoblastic peri-implant activity was carried out using single photon emission computerized tomography. Healing was within normal limits. Four months after stage I, the 2 implants were uncovered and considered clinically and radiographically integrated. The osteoblastic activity was judged similar bet-ween the 2 implants in terms of quality of biological response. Osseous scintigraphy and the achievement of implant osseointegration demonstrate the lack of toxicity of the topical application of the biphosphonate alendronate during the initial osseous healing. However, new experimental studies and clinical trials are necessary to confirm the results obtained.