Laser Therapy Effects on Periodontal Status: A Randomized Study Using Gaussian Network Analysis and Structural Equation Modeling Approach.

Background and Objectives: This paper aims to assess the role of laser therapy in periodontitis through an innovative approach involving computational prediction and advanced modeling performed through network analysis (Gaussian graphical models-GGMs) and structural equations (SEM). Materials and Methods: Forty patients, exhibiting periodontal pockets with a minimum depth of 5 mm, were randomly divided into two groups: a control group and a laser group. Four specific indicators were measured for each tooth, namely periodontal pocket depth (PPD), clinical attachment level (CAL), bleeding on probing (BOP), and plaque index (PI), and the mean of six measured values was recorded at five time markers (baseline, 6 months, 1 year, 2 years, and 4 years). The assessment algorithm included enrollment, measurements, and differential non-surgical periodontal treatment, according to the group allocation. Scaling, root planing, and chlorhexidine 1% were conducted for the control group, and scaling, root planing and erbium, chromium:yttrium-scandium-gallium-garnet (Er,CR:YSGG) laser therapy were conducted for the laser group. Results: The main results highlight that the addition of laser treatment to scaling and root planing led to notable clinical improvements, decreasing the PPD values, reducing the BOP scores, and increasing the CAL. Conclusions: Notable relationships between the specific indicators considered were highlighted by both the GGMs and by SEM, thus confirming their suitability as proxies for the success of periodontal treatment.

Effects of Osseodensification on Primary Stability of Cylindrical and Conical Implants-An Ex Vivo Study.

Primary stability is an important factor for dental implant success. In the past years, a new method for bone site preparation was introduced, named osseodensification (OD). OD produces a condensation of the trabecular portion of the bone, increasing bone-to-implant contact and primary stability. This study aims to compare the effect of OD in cylindrical and conical implants to conventional instrumentation. A total of forty implants, divided into four groups, were placed in porcine tibia: cylindrical conventional (1a), cylindrical OD (1b), conical conventional (2a) and conical OD (2b). Each implant was measured for implant stability quotient (ISQ), insertion torque (IT) and removal torque (RT). Group 2b showed the higher values for each of the evaluated parameters; groups 1b and 2b showed better results than 1a and 2a, respectively. Regarding the IT and RT, group 1b achieved higher values than group 2a, but not for ISQ. The inter-group comparison showed significant difference between groups 1a vs 2a, 1a vs 2b and 1b vs 2b for ISQ and 1a vs 1b and 1a vs 2b for RT analysis. OD resulted in improved ISQ, IT and RT of both cylindrical and conical implants.

Cranial and Odontological Methods for Sex Estimation-A Scoping Review.

The estimation of sex from osteological and dental records has long been an interdisciplinary field of dentistry, forensic medicine and anthropology alike, as it concerns all the above mentioned specialties. The aim of this article is to review the current literature regarding methods used for sex estimation based on the skull and the teeth, covering articles published between January 2015 and July 2022. New methods and new approaches to old methods are constantly emerging in this field, therefore resulting in the need to summarize the large amount of data available. Morphometric, morphologic and biochemical analysis were reviewed in living populations, autopsy cases and archaeological records. The cranial and odontological sex estimation methods are highly population-specific and there is a great need for these methods to be applied to and verified on more populations. Except for DNA analysis, which has a prediction accuracy of 100%, there is no other single method that can achieve such accuracy in predicting sex from cranial or odontological records.

Additive Manufactured Polymers in Dentistry, Current State-of-the-Art and Future Perspectives-A Review.

3D-printing application in dentistry not only enables the manufacture of patient-specific devices and tissue constructs, but also allows mass customization, as well as digital workflow, with predictable lower cost and rapid turnaround times. 4D printing also shows a good impact in dentistry, as it can produce dynamic and adaptable materials, which have proven effective in the oral environment, under its continuously changing thermal and humidity conditions. It is expected to further boost the research into producing a whole tooth, capable to harmoniously integrate with the surrounding periodontium, which represents the ultimate goal of tissue engineering in dentistry. Because of their high versatility associated with the wide variety of available materials, additive manufacturing in dentistry predominantly targets the production of polymeric constructs. The aim of this narrative review is to catch a glimpse of the current state-of-the-art of additive manufacturing in dentistry, and the future perspectives of this modern technology, focusing on the specific polymeric materials.

Advanced Materials for Oral Application.

This Special Issue of Materials explores the wide variety of dental materials, which enables the dentists and dental technicians to select the most suitable therapeutic solution for each patient [...].

COVID-19 and Its Repercussions on Oral Health: A Review.

In 2019, a new type of coronavirus, SARS-CoV-2, the causing agent of COVID-19, was first detected in Wuhan, China. On 11 March 2020, the World Health Organization declared a pandemic. The manifestations of COVID-19 are mostly age-dependent and potentially more severe in cases with involved co-morbidities. The gravity of the symptoms depends on the clinical stage of the infection. The most common symptoms include runny nose and nasal congestion, anosmia, dysgeusia or hypogeusia, diarrhea, nausea/vomiting, respiratory distress, fatigue, ocular symptoms, diarrhea, vomiting, and abdominal pain. These systemic conditions are often accompanied by skin and mucosal lesions. Oral lesions reported in patients with COVID-19 include: herpex simplex, candidiasis, geographic tongue, aphthous-like ulcers, hemorrhagic ulcerations, necrotic ulcerations, white hairy tongue, reddish macules, erythematous surfaces, petechiae, and pustular enanthema. It is still unclear if these manifestations are a direct result of the viral infection, a consequence of systemic deterioration, or adverse reactions to treatments. Poor oral hygiene in hospitalized or quarantined COVID-19 patients should also be considered as an aggravating condition. This narrative review is focused on presenting the most relevant data from the literature regarding oral manifestations related to SARS-CoV-2, as well as the challenges faced by the dental system during this pandemic. A routine intraoral examination is recommended in COVID-19 patients, either suspected or confirmed, as, in certain cases, oral manifestations represent a sign of severe infection or even of a life-threatening condition. It is our belief that extensive knowledge of all possible manifestations, including oral lesions, in cases of COVID-19 is of great importance in the present uncertain context, including new, currently emerging viral variants with unknown future impact.

Advanced Biomaterials and Techniques for Oral Tissue Engineering and Regeneration-A Review.

The reconstruction or repair of oral and maxillofacial functionalities and aesthetics is a priority for patients affected by tooth loss, congenital defects, trauma deformities, or various dental diseases. Therefore, in dental medicine, tissue reconstruction represents a major interest in oral and maxillofacial surgery, periodontics, orthodontics, endodontics, and even daily clinical practice. The current clinical approaches involve a vast array of techniques ranging from the traditional use of tissue grafts to the most innovative regenerative procedures, such as tissue engineering. In recent decades, a wide range of both artificial and natural biomaterials and scaffolds, genes, stem cells isolated from the mouth area (dental follicle, deciduous teeth, periodontal ligament, dental pulp, salivary glands, and adipose tissue), and various growth factors have been tested in tissue engineering approaches in dentistry, with many being proven successful. However, to fully eliminate the problems of traditional bone and tissue reconstruction in dentistry, continuous research is needed. Based on a recent literature review, this paper creates a picture of current innovative strategies applying dental stem cells for tissue regeneration in different dental fields and maxillofacial surgery, and offers detailed information regarding the available scientific data and practical applications.

Corrosion Susceptibility and Allergy Potential of Austenitic Stainless Steels.

Although called stainless steels, austenitic steels are sensitive to localized corrosion, namely pitting, crevice, and intergranular form. Seventeen grades of steel were tested for localized corrosion. Steels were also tested in general corrosion and in galvanic couplings (steels-precious alloys) used in watchmaking applications. The evaluations have been carried out in accordance with the ASTM standards which specifically concern the forms of corrosion namely, general (B117-97, salt fog test), pitting (G48-11, FeCl3), crevice (F746-87) and intergranular (A262-15, Strauss chemical test and G108-94, Electrochemical potentiodynamic reactivation test). All tests revealed sensitivity to corrosion. We have noticed that the transverse face is clearly more sensitive than the longitudinal face, in the direction of rolling process. The same conclusion has been drawn from the tests of nickel release. It should be pointed out that, despite the fact that the grade of steel is in conformity with the classification standards, the behavior is very different from one manufacturer to another, due to parameters dependent on the production process, such as casting volume, alloying additions, and deoxidizing agents. The quantities of nickel released are related to the operations involved in the manufacturing process. Heat treatments reduce the quantities of nickel released. The surface state has little influence on the release. The hardening procedures increase the quantities of nickel released. The quantities of released nickel are influenced by the inclusionary state and the existence of the secondary phases in the steel structure. Another aspect is related to the strong dispersion of results concerning nickel release and corrosion behavior of raw materials.

An Insight into the Structural Diversity and Clinical Applicability of Polyurethanes in Biomedicine.

Due to their mechanical properties, ranging from flexible to hard materials, polyurethanes (PUs) have been widely used in many industrial and biomedical applications. PUs' characteristics, along with their biocompatibility, make them successful biomaterials for short and medium-duration applications. The morphology of PUs includes two structural phases: hard and soft segments. Their high mechanical resistance featuresare determined by the hard segment, while the elastomeric behaviour is established by the soft segment. The most important biomedical applications of PUs include antibacterial surfaces and catheters, blood oxygenators, dialysis devices, stents, cardiac valves, vascular prostheses, bioadhesives/surgical dressings/pressure-sensitive adhesives, drug delivery systems, tissue engineering scaffolds and electrospinning, nerve generation, pacemaker lead insulation and coatings for breast implants. The diversity of polyurethane properties, due to the ease of bulk and surface modification, plays a vital role in their applications.

Are Zirconia Bioceramics and Ceramics Intended to Come in Contact with Skin Inert?

Generally speaking, ceramic materials are insensitive to corrosion, compared to most other materials. The present study questions the fact that ceramics are inert. Two major aspects are to be considered: the stability of zirconia over time, the stable tetragonal phase transforming into an unstable monoclinic form; the multitude of manufacturing methods, using various additives, sintering additives, oxides mixing, impurities, grain boundaries, and porosities which strongly influence the corrosion behavior and chemical degradation. In case of the investigated ceramics two paths were pursued:a) Dissolutions of ceramics in a mixture of HNO3 60% and HF 40% ultrapure medium.b) Release of cations from ceramics in various mediums:dental bioceramics in a 0.07 M HCl medium and a 0.1% NaF+0.1% KF medium; ceramics used in jewelry and watchmaking applications in a HCl 0.07 M medium and an artificial sweat medium. By inductively coupled plasma-optical emission spectrometry/mass spectrometry (ICP-OES/MS), traces of significant chemical elements were assessed: Hf, Cr, Y, As, Pb, Al, Fe, Cu, Se, Sb, La, Ni, Co, Sb, Ta, Te, Ba, Sm, Nb, Hg, Cd, Sr, As and Se. In ceramics used in jewelry and watchmaking applications the concentrations found vary from one ceramic to another, including toxic elements such as Te, Ba, As, Pb, Sm, Hg and Cd, therefore being technical zirconia ceramics which are not intended for the medical field. For ceramics used in jewelry and watchmaking applications a screening identification test for Ni, Co, Cu and Fe with strips of type Merckoquant® (Merck, Kenilworth, NJ, USA) was also performed. The obtained data prove that the zirconia ceramics in question are far from being "inert".

Comparative Analysis of the Corrosion Resistance of Titanium Alloys Intended to Come into Direct or Prolonged Contact with Live Tissues.

The evaluation of the biological safety and degradation of materials is quite important for risk assessment in various biomedical applications. In this study, two procedures were followed to characterize the corrosion resistance of different Ti-based alloys. The first one consisted of performing specific electrochemical tests (open circuit potential, linear resistance polarization, Tafel plots, potentiodynamic polarization) in order to highlight their behavior to the general and localized corrosion. The static and dynamic fatigue cycles combined with crevice corrosion conducted on a new prototype have completed the study. The second procedure followed was a cations extraction investigation (by inductively coupled plasma mass spectrometry) in order to verify the ionic permeability of the oxides layers formed on the surfaces. Optical and scanning electron microscopy were used for surface analysis. It was noticed that in these two electrolytes, the bulk Ti-based alloys presented an almost similar general corrosion behavior. The small differences of behavior for Ti6Al4V scaffolds were correlated to the surface oxidation and roughness (owing to the selective laser melting process). The Ti alloys presented no traces of localized corrosion at the end of the test. The fatigue cycles revealed that a strong and adhesive oxides film was formed during the static cycles (difficult to remove even during the depassivation steps). The concentration of cations released was at the detection limit, revealing very good passivation films, in adequacy with the all the other results.

Oral Bone Tissue Engineering: Advanced Biomaterials for Cell Adhesion, Proliferation and Differentiation.

The advancements made in biomaterials have an important impact on oral tissue engineering, especially on the bone regeneration process. Currently known as the gold standard in bone regeneration, grafting procedures can sometimes be successfully replaced by a biomaterial scaffold with proper characteristics. Whether natural or synthetic polymers, biomaterials can serve as potential scaffolds with major influences on cell adhesion, proliferation and differentiation. Continuous research has enabled the development of scaffolds that can be specifically designed to replace the targeted tissue through changes in their surface characteristics and the addition of growth factors and biomolecules. The progress in tissue engineering is incontestable and research shows promising contributions to the further development of this field. The present review aims to outline the progress in oral tissue engineering, the advantages of biomaterial scaffolds, their direct implication in the osteogenic process and future research directions.

Platelet-Rich Fibrin and its Emerging Therapeutic Benefits for Musculoskeletal Injury Treatment.

New therapies that accelerate musculoskeletal tissue recovery are highly desirable. Platelet-rich fibrin (PRF) is a leukocyte- and platelet-rich fibrin biomaterial that acts as a binding site for both platelets and growth factors. Through increasing the local concentration of growth factors at specific tissues, PRF promotes tissue regeneration. PRF has been frequently used in combination with bone graft materials to reduce healing times and promote bone regeneration during maxillofacial surgery. However, its benefits during muscle repair and recovery are less well-documented. Here, we perform a narrative review on PRF therapies and muscle injuries to ascertain its beneficial effects. We reviewed the factors that contribute to the biological activity of PRF and the published pre-clinical and clinical evidence to support its emerging use in musculoskeletal therapy. We include in vitro studies, in vivo animal studies and clinical articles highlighting both the success and failures of PRF treatment. PRF can promote the healing process when used in a range of orthopaedic and sports-related injuries. These include cartilage repair, rotator cuff surgery and anterior cruciate ligament surgery. However, conflicting data for these benefits have been reported, most likely due to inconsistencies in both PRF preparation protocols and dosing regimens. Despite this, the literature generally supports the use of PRF as a beneficial adjuvant for a range of chronic muscle, tendon, bone or other soft tissue injuries. Further clinical trials to confirm these benefits require consistency in PRF preparation and the classification of a successful clinical outcome to fully harness its potential.

Corrosion Resistance of Stainless Steels Intended to Come into Direct or Prolonged Contact with the Skin.

The biocompatibility of materials in contact with a living tissue becomes a puzzle in the overall picture of assessing the toxic effects of chemicals that come into contact with us. Allergic reactions to substances are a significant and growing health problem affecting large parts of the population in Europe. Wristwatches are objects worn in prolonged contact with the skin, being subject to localized corrosion, especially pitting and crevice types, in sulfide-chloride medium, and high wear in the bracelets joints. Watches of medium quality are usually made of stainless steels. The X2 CrNiMo 17-12-2 316L grade as well as X1 CrNiMo 20-25-5 Cu 1 or 904L are commonly used, having good resistance to generalized corrosion. The passive layer is nevertheless insufficient to ensure complete immunity in all cases of localized corrosion encountered during wear. For this reason, a high-corrosion-resistant steel: X1 CrNiMo 18-15-4 N 0.15 or 317LMN, from three different suppliers was evaluated. Metallographic characterization was carried out. The corrosion behavior evaluation was performed for the generalized corrosion, pitting and crevice corrosion and galvanic corrosion. Galvanic couples steel 317LMN-gold 18K alloy 3N and gold 18K 5M were used. The results of the generalized and pitting corrosion test indicated three basic groups. All of the 317LMNs were similar. The 316L variants tested noticeably worse. The 904Ls were difficult to discern, but certainly easier than the 316Ls and, possibly, at least comparable to the 317LMNs.