In vitro comparative study on the mechanical behavior of Zirconia and Polyetheretherketone in applied dental sciences.

OBJECTIVE: Recently, Zirconia and polyaryletherketone (PEEK) have attracted increasing interest as reliable and safe materials in dental applications, mainly because of their good biomechanical characteristics. The aim of this study was to investigate the response to different loads by prosthetic frameworks for supported fixed partial dentures (FPDs), thus simulating osseointegrated implants. MATERIALS AND METHODS: The specimens were divided into two groups (n= 5 each). Group A: FDPs in zirconia-ceramic; Group B: FDPs in PEEK-composite. These 2 groups were subjected to vertical loads so to evaluate structural deformation; then, they have been analyzed by scanning electron microscopy (SEM) at different magnifications. RESULTS: In tested samples, different types of mechanical failures have been observed. In Zirconia-specimens, chipping is the main failure noticed in this study, mostly in distal margins of the structure. Also, peek-specimens show failure and fracture. CONCLUSIONS: Zirconia and PEEK could be considered both good materials, but several investigations are needed to use these materials as an alternative to metals for fixed partial dentures.

Gender medicine: the impact of probiotics on male patients.

PURPOSE: Numerous studies in the literature confirm the importance of the use of probiotics in inflammatory states of the prostate in humans. Our pilot study aimed to test probiotics strains ability to improve urinary bacterial load in male subjects. METHODS: Twenty healthy men aged 55-65 years, with recurrent urinatory infections were enrolled and randomized into 2 groups. Urine culturing to detect Enterobacteriaceae (Escherichia Coli and Enterococcus faecalis) was performed at baseline and at 12 weeks after the starting of the study. RESULTS: We found that taking the probiotic reduces the bacterial load of E. coli and E. faecalis in urine cultures. The use of the probiotic in these inflammatory states does not affect the change in weight in the tested subjects. CONCLUSIONS: Our data confirm and improve the main results reported in the scientific literature on the importance of taking probiotics in prostatitis.

The alteration of stress-related physiological parameters after probiotics administration in oral surgeons with different degrees of surgical experience.

PURPOSE: Stress is a multifactorial and complex pathway, gaining growing attention from the healthcare community. Surgeons are subjected to higher levels of stress, due to surgical procedures that are demanding and repetitive; unfortunately, high-stress levels may also cause side-effects, as surgical mistakes. This study aimed to evaluate the efficacy of specific probiotics strains formula on stress levels in oral and maxillofacial surgeons, to improve their quality of life. METHODS: We have investigated the hormonal (salivary Cortisol; sC), immune (salivary Immunoglobulin A; sIgA) and cardiovascular (Heart rate, HR, and systolic blood pressure, SBP) responses induced by stress conditions in 40 oral surgeons, randomly selected and allocated, according to their experience level, in three categories: senior, expert, and junior. RESULTS: The results described how the number of heartbeats/ minute and SBP are slightly raised in all surgeons at different timepoints. Such data allow us to assess that work-related stress can induce an increase in cardiovascular parameters, even if they are not significantly modified by the use of probiotics. On the other hand, our data indicate that 10 weeks of probiotic integration may induce the improvement of other stress-related physiological parameters in oral surgeons with different degrees of surgical experience, such as the salivary cortisol levels, even under stress conditions. Moreover, in the test group (probiotics administration), the immunoglobulin levels were higher than the control (placebo administration) group: this happens as a consequence of the regular use of probiotics, which may induce an increased number of IgA producing cells. DISCUSSION: Our data indicated that 10 weeks of probiotics-enriched diet modify some stress-related physiological parameters in oral surgeons with different degrees of surgical experience, but it does not impact on the overall cardiovascular risk.

Additive manufacturing and biomimetic materials in oral and maxillofacial surgery: a topical overview.

Additive manufacturing (AM) is the term used for different and complex techniques to manufacture products with complex morphology, often referred to as "custom-made". The product is made without needing to melt the material into pre-formed molds, nor to remove it from an initial mass, as happens in subtractive processes. The additive methodology gives the AM enormous potential in the widest fields of application, from aerospace to biomedical, from dental to maxillofacial. This wide range of AM technologies can be applied to different types of polymeric materials such as plastics, resins and biopolymers that are processed to obtain optimal scaffolds. The most common synthetic and biocompatible polymeric materials for the production of biocompatible scaffolds are: polylactic acid (PLA), polycaprolactone acid (PLC) and polylactic-co-glycolic acid (PLGA); such materials interact effectively with cell behavior and tissue development. These materials are degradable in the physiological environment and the degradation products do not have harmful effects. In conclusion, new biomaterials are increasingly being studied as possible therapeutic remedies. Advances in tissue engineering are leading to the development of new scaffolds useful for bone regeneration and therefore potentially valid for applications in maxillofacial surgery.

Updates in regenerative medicine applied to dental sciences.

Mesenchymal stem cells (MSCs) are found in high concentrations in several tissues, such as umbilical cord, adipose tissue and dental tissue. Dental stem cells reside in many areas of the oral cavity. Thanks to their abilities, dental stem cells could be used to treat diseases and to understand the basic mechanisms of developmental pathologies. There are currently numerous ongoing clinical trials evaluating a broad spectrum of conditions and situations using different stem cell populations. However, stem cell studies are raising profound ethical questions that weigh on the world of scientific research. Stem cells are always a hot topic in the scientific community. Their use is related also to their banking, as cell manipulation is also often related to medical and ethical issues. Many biomedical studies aim to treat diseases that were previously considered incurable with MSCs. All this has created the need to quickly and safely storage stem cells, usually in a stem cell biobank (SCB). Regenerative medicine is the most important approach for achieving complete tissue regeneration using stem cells isolated from adult tissues, embryonic stem cells, but also through the application of induced pluripotent stem cells (iPSC). iPSCs are non-pluripotent cells that are engineered to acquire the ability to differentiate into all different types of cells. In conclusion, the daily use of stem cells in regenerative procedures is still far from being safe and predictable, especially because of the biomedical component, often requiring experienced biologists and complex technologies for cell manipulation and cell banking. .

3D software scanning, processing and archiving palatal rugae: "identity base" technology.

The palatal rugae, which are anatomically described as folds or wrinkles of the palate, are located on the anterior third of the palate on each side of the palatal raphe and behind the incisive papilla. The use of palatal rugae for personal identification was suggested several years ago, and attracted interest from different researchers which created different classifications, still used in scientific literature. The "identity base" (IB) system has as its object a complex information system and a personal identification protocol by means of three-dimensional palatal scans in digital format. The usefulness of this system is based on the management needs of big data. For example, in the field of forensic odontology, IB can be useful in the identification of a living or cadaver subject; and can estimate the age of a human subject. Moreover, IB stores its associated biometric data. The IB system demonstrated to overcome the issues shown by other similar systems of digital image storage. Furthermore, its high accuracy in the identification process makes IB a reliable tool for institutions in the management of immigrants, as well as in the archiving of people under restrictive measures. Finally, IB is also a system for sharing and processing clinical images, useful in dental prosthetics to reduce the number of steps from the first visit to dental prosthesis. The next generation of big-data archiving will speak the same language as IB: the route has been already set out.

Digital flow in medicine and dentistry: what’s new?

The increasing requirements of standardization in medical applications have led physicians towards a deep revision of their protocols. The phenomenon of ‘digital health’ has revolutionized the way a patient accesses medical information, but it has also improved the way the doctor handles the surgical and clinical phases. In digital dentistry, the working steps are mainly reported as digital image acquisition, preparation and/or processing of data, device production and clinical application on patients; the new technologies have brought significant benefits to both the dentist and the patient. Digital processing of anatomical data uses virtual models, which represent a precise representation of the patient’s anatomy. Recent advances in digital image acquisition technologies and the enormous complexity of modern software have made intraoral scans possible to realize digital dental arch models, however, the digital model is able to report substantial information to the clinician. Therefore, both complex surgeries and less invasive local therapies can be easily planned, with an accurate analysis of biological regulators improving the regenerative procedures, to achieve the best results in a shorter treatment.

Age estimation in children by measurement of open apices in teeth with Bayesian calibration approach.

Age estimation from teeth by radiological analysis, in both children and adolescents, has wide applications in several scientific and forensic fields. In 2006, Cameriere et al. proposed a regression method to estimate chronological age in children, according to measurements of open apices of permanent teeth. Although several regression models are used to analyze the relationship between age and dental development, one serious limitation is the unavoidable bias in age estimation when regression models are used. The aim of this paper is to develop a full Bayesian calibration method for age estimation in children according to the sum of open apices, S, of the seven left permanent mandibular teeth. This cross-sectional study included 2630 orthopantomographs (OPGs) from healthy living Italian subjects, aged between 4 and 17 years and with no obvious developmental abnormalities. All radiographs were in digital format and were processed by the ImageJ computer-aided drawing program. The distance between the inner side of the open apex was measured for each tooth. Dental maturity was then evaluated according to the sum of normalized open apices (S). Intra- and inter-observer agreement was satisfactory, according to an intra-class correlation coefficient of S on 50 randomly selected OPGs. Mean absolute errors were 0.72 years (standard deviation 0.60) and 0.73 years (standard deviation 0.61) in boys and girls, respectively. The mean interquartile range (MIQR) of the calibrating distribution was 1.37 years (standard deviation 0.46) and 1.51 years (standard deviation 0.52) in boys and girls, respectively. Estimate bias was ßERR=-0.005 and 0.003 for boys and girls, corresponding to a bias of a few days for all individuals in the sample. Neither of the ßERR values was significantly different from 0 (p>0.682). In conclusion, the Bayesian calibration method overcomes problems of bias in age estimation when regression models are used, and appears to be suitable for assessing both age and age distribution in children according to tooth maturity.

Retrospective Analysis of the Correlation Between the Facial Biotype and the Inclination of the Upper Canine Cusp Axis to the Occlusal Plane.

Permanent maxillary canines are the second most frequently impacted teeth and the prevalence of this clinical condition is estimated to be 1-2% in the general population. The diagnosis of maxillary canine impaction should be based on both clinical and radiographic examinations. The aim of this study was to evaluate the presence of a correlation between the facial biotype and the inclination of the upper cusp axis. A correlation between the total radicular length of the lateral incisors was also evaluated, by comparing the side of impaction with the healthy side. Twenty three patients with a diagnosis of unilateral upper cusp impaction were recruited. For each patient, dental casts and radiographic material (panoramic radiographs and lateral cephalograms) were examined. Statistical analyses were done with Spearman's rank correlation coefficient or Spearman's rho (ρ). X-ray examinations demonstrated that canine impaction was associated to other dental anomalies (32% of the sample). The mean α angle measurements were 22.9° ± 4.1°, and mean values of the ß angle were 34.7°± 4.0°. The mean distance "d" value was 14.6 mm ± 1.2 mm. The mean values of the angle between the upper cusp axis and the perpendicular-to-Fh plane were 20.8° ± 2.6°. Among the 23 subjects recruited, 5 showed values included in the range 25°-45° and 1 an inclination > 45°. The results obtained in the present study demonstrate a significant inverse correlation between the MM angle and the inclination of the upper cusp axis to the perpendicular-to-Fh plane.

Metals used in maxillofacial surgery.

The goal of maxillofacial surgery is to restore the shape and functionality of maxillofacial region. In the past years, there has been a tremendous progress in this field because of significant advances in biotechnology that provided innovative biomaterials to efficiently reconstruct the maxillofacial injured region. By using appropriate selection of the implant biomaterial, it is possible to reconstruct the native tissue, both in form and function. The ideal biomaterial should mimic native tissues regarding density, strength, and modulus of elasticity. Autografts are currently the gold standard for replacement of missing tissues, but synthetic biomaterials have been widely used because they eliminate the discomfort to take the replacement tissue from the donor site. Among synthetic biomaterials, different metals may be utilized to efficiently reconstruct the maxillofacial injured region. This article makes an effort to summarize the most important metals in use in maxillofacial surgery, and point out advantages and disadvantage of each type.

Energy transfer upon collision of selectively excited CO2 molecules: State-to-state cross sections and probabilities for modeling of atmospheres and gaseous flows.

Carbon dioxide molecules can store and release tens of kcal/mol upon collisions, and such an energy transfer strongly influences the energy disposal and the chemical processes in gases under the extreme conditions typical of plasmas and hypersonic flows. Moreover, the energy transfer involving CO2 characterizes the global dynamics of the Earth-atmosphere system and the energy balance of other planetary atmospheres. Contemporary developments in kinetic modeling of gaseous mixtures are connected to progress in the description of the energy transfer, and, in particular, the attempts to include non-equilibrium effects require to consider state-specific energy exchanges. A systematic study of the state-to-state vibrational energy transfer in CO2 + CO2 collisions is the focus of the present work, aided by a theoretical and computational tool based on quasiclassical trajectory simulations and an accurate full-dimension model of the intermolecular interactions. In this model, the accuracy of the description of the intermolecular forces (that determine the probability of energy transfer in molecular collisions) is enhanced by explicit account of the specific effects of the distortion of the CO2 structure due to vibrations. Results show that these effects are important for the energy transfer probabilities. Moreover, the role of rotational and vibrational degrees of freedom is found to be dominant in the energy exchange, while the average contribution of translations, under the temperature and energy conditions considered, is negligible. Remarkable is the fact that the intramolecular energy transfer only involves stretching and bending, unless one of the colliding molecules has an initial symmetric stretching quantum number greater than a threshold value estimated to be equal to 7.

Clinical Management of a Peri-Implant Giant Cell Granuloma.

Purpose. Implant therapy plays an important role in contemporary dentistry with high rates of long-term success. However, in recent years, the incidence of peri-implantitis and implant failures has significantly increased. The peripheral giant cell granuloma (PGCG) rarely occurs in peri-implant tissues and it is clinically comparable to the lesions associated with natural teeth. Therefore, the study of possible diseases associated with dental implants plays an important role in order to be able to diagnose and treat these conditions. Materials and Methods. This report described a 60-year-old Caucasian male who presented a reddish-purple pedunculated mass, of about 2 cm in diameter, associated with a dental implant and the adjacent natural tooth. Results. An excisional biopsy was performed and the dental implant was not removed. Histological examination provided the diagnosis of PGCG. After 19-month follow-up, there were no signs of recurrence of peri-implantitis around the implant. Conclusion. The correct diagnosis and appropriate surgical treatment of peri-implant giant cell granuloma are very important for a proper management of the lesion in order to preserve the implant prosthetic rehabilitation and prevent recurrences.

Adult or not? Accuracy of Cameriere's cut-off value for third molar in assessing 18 years of age for legal purposes.

AIM: The discovery of reliable means to determine the age of an individual is a fundamental objective in forensic medicine, in consideration of the constant increase of illegal immigration into the European community. In 2008 Cameriere et al. developed a method based on the relationship between age and the third molar index (I3m), which assesses the degree of maturation of the third molar through measurements made on orthopantomography. The purpose of this work was to test the accuracy of Cameriere's cut-off for I3m as a tool to assess full age (18) on a new sample of living subjects. METHODS: Orthopantomographs of 287 Italian living subjects aged between 13 and 22 years have been randomly selected and included in the study. Identification number, gender, date of birth and date of execution of the radiograph were recorded for each patient on a Microsoft Excel® spreadsheet. Radiographs were digitalized and analyzed using a computerized image-processing program (Adobe® Photoshop® CS4). RESULTS: The results show that the sensitivity of the test was 84.1% and the specificity was 92.5%. The estimated post-test probability was 90.1%, with a confidence interval of 95% (83.6%, 95.2%). Thus, the probability that a person being positive to the test has 18 or more years of age was 90.1%. CONCLUSION: The results highlight the contribution of Cameriere's cut-off value for the I3m in the assessment of full age, always remembering that the simultaneous employment of previously introduced complementary methods is essential for the purpose.

CHARGE syndrome: an overview on dental and maxillofacial features.

OBJECTIVES: CHARGE is an acronym referring to the aspects of this rare syndromic condition. Patients with CHARGE association are today considered as subjects lacking in pathognomonic dental alterations. The present study is aimed at adding to the body of evidence of the cases reported in literature and the continuous clinical research which show a clinical picture which is strongly associated with patients afflicted by this syndrome. PATIENTS AND METHODS: We report a case-series of 8 patients with CHARGE syndrome. The dental features associated with CHARGE syndrome are from case-reports, but without a congruity that can lead to a definition of the dental condition typical of the CHARGE phenotype. CONCLUSIONS: The systemic problems affecting these patients are predominant in compromising their quality of life: this is the reason for a frequent lack of a diagnostics and interceptive phase, relative to oral diseases. We report new oral pathological conditions affecting CHARGE patients. Knowledge of these pathological conditions may induce dentists to carry out specific diagnoses of these patients, thus, avoiding the deterioration of oral conditions.

Diagnosis and treatment of a rare case of adenomatoid odontogenic tumor in a young patient affected by attenuated familial adenomatosis polyposis (aFAP): case report and 5 year follow-up.

BACKGROUND: The adenomatoid odontogenic tumor (AOT) is a quite rare odontogenic tumor, with an incidence rate of approximately 12 cases/year worldwide. Attenuated familial adenomatous polyposis (aFAP) is a syndrome characterized by a significant risk to develop colon cancer. The aim of the paper is to describe a case never reported before in the literature: an AOT developed in a patient with aFAP; moreover, we want to show how it appears 5 years after surgery and after the regeneration of the eroded bone tissue, using the Platelet-Rich Fibrin (PRF) as filling material. CASE PRESENTATION: We report the case of a female 18 years old patient, affected by aFAP; she comes to us with a swelling on the right hemi-face. We performed several radiological exams, and they showed a neoformation approximately 2 cm in diameter: this neoformation packed the upper right canine, therefore, we hypothesized a dentigerous cyst. We decided to proceed to open biopsy and enucleation of the lesion. An intra-operative endodontic treatment on the adjacent partially resorbed teeth was also performed. Finally, we performed a reconstruction of eroded bone tissue, by use of Platelet-Rich Fibrin as filling material. The samples fixed and embedded in paraffin have led to the diagnosis of AOT. After 5 years from the surgery, we did not find any clear sign of relapse, in addition, the use of PRF has favored an optimal osteogenesis at the surgical site. CONCLUSIONS: Undoubtedly, a correct diagnosis of AOT allows to have a more performing clinical and surgical approach. Furthermore, this case could document a new manifestation of aFAP in extra-intestinal site. The onset of an AOT is quite rare in the general population, and this rarity could represent a critical point for its diagnosis; AOT onset in a patient with aFAP is a finding that could represent a new element of diagnosis and, therefore, the starting point to perform a more effective therapy.

Inflammation and iron metabolism in adult patients with epilepsy: does a link exist?

PURPOSE: Inflammation has been shown to play a key role in epilepsy, and may also affect both the iron status and metabolism. Consequently, a relationship between iron metabolism and neuronal excitability and seizures could be expected. METHODS: We aimed at characterizing in 37 adult patients affected by focal epilepsy during the interictal period serum inflammatory cytokines, such as interleukin 6 (IL-6), IL-6 soluble receptor (IL6-sR), interleukin 1 (IL-1), IL-1 receptor-antagonist (IL-1RA), tumor necrosis factor-α (TNF-α), and markers of iron status and metabolism: hemoglobin concentration (Hgb), mean corpuscular volume (MCV), hematocrit (Hct) red blood cell (RBC) count, serum iron and copper concentrations, ceruloplasmin (iCp), the ceruloplasmin enzymatic activity (eCp), the specific ceruloplasmin activity (eCp/iCp), total ferroxidase activity, transferrin (Tf), serum ferritin (SF), Tf saturation (Sat-Tf), and ratio of ceruloplasmin to transferrin (Cp/Tf). We investigated the correlations between these biological markers as well their relationship with patients' clinical features. A group of 43 healthy subjects had the same serologic measurements to serve as controls. RESULTS: Our findings showed in the group of patients with epilepsy an increase of IL-6 (p=0.026) and a decrease of TNF-α (p=0.002) with respect to healthy subjects. For the first time, we also detected significant changes in iron metabolism as an increase of Cp/Tf (p=0.011) and a decrease of Tf (p=0.031), possibly driven by cytokine modifications and consistent with inflammation as acute phase and antioxidant activity markers. Accordingly, TNF-α positively correlated with Tf (p=0.005). Finally, a significant positive correlation between seizures frequency and eCp (p=0.046) and inversely with Hgb (p=0.038) and Hct (p=0.041), and an inverse correlation between TNF-α and the duration of epilepsy (p=0.021) was detected. CONCLUSIONS: Our findings demonstrate a relevant relationship between epilepsy and systemic inflammation, with a consistent link between seizures, inflammatory cytokines (IL-6 and TNF-α) and iron regulation and metabolism, as acute phase and antioxidant markers.