Experimental Study on Mechanical Properties of Different Resins Used in Oral Environments.

Background and Objectives: Acrylic resins remain the materials of choice for removable prosthesis due to their indisputable qualities. The continuous evolution in the field of dental materials offers practitioners today a multitude of therapeutic options. With the development of digital technologies, including both subtractive and additive methods, workflow has been considerably reduced and the precision of prosthetic devices has increased. The superiority of prostheses made by digital methods compared to conventional prostheses is much debated in the literature. Our study's objective was to compare the mechanical and surface properties of three types of resins used in conventional, subtractive, and additive technologies and to determine the optimal material and the most appropriate technology to obtain removable dentures with the highest mechanical longevity over time. Materials and Methods: For the mechanical tests, 90 samples were fabricated using the conventional method (heat curing), CAD/CAM milling, and 3D printing technology. The samples were analyzed for hardness, roughness, and tensile tests, and the data were statistically compared using Stata 16.1 software (StataCorp, College Station, TX, USA). A finite element method was used to show the behavior of the experimental samples in terms of the crack shape and its direction of propagation. For this assessment the materials had to be designed inside simulation software that has similar mechanical properties to those used for obtaining specimens for tensile tests. Results: The results of this study suggested that CAD/CAM milled samples showed superior surface characteristics and mechanical properties, comparable with conventional heat-cured resin samples. The propagation direction predicted by the finite element analysis (FEA) software was similar to that observed in a real-life specimen subjected to a tensile test. Conclusions: Removable dentures made from heat-cured resins remain a clinically acceptable option due to their surface quality, mechanical properties, and affordability. Three-dimensional printing technology can be successfully used as a provisional or emergency therapeutic solution. CAD/CAM milled resins exhibit the best mechanical properties with great surface finishes compared to the other two processing methods.

The Role of Natural Compounds in Optimizing Contemporary Dental Treatment-Current Status and Future Trends.

For a long period of time, natural remedies were the only ailment available for a multitude of diseases, and they have proven effective even after the emergence of modern medicine. Due to their extremely high prevalence, oral and dental disorders and anomalies are recognized as major public health concerns. Herbal medicine is the practice of using plants with therapeutic characteristics for the purpose of disease prevention and treatment. Herbal agents have made a significant entry into oral care products in recent years, complementing traditional treatment procedures due to their intriguing physicochemical and therapeutic properties. There has been a resurgence of interest in natural products because of recent updates, technological advancements, and unmet expectations from current strategies. Approximately eighty percent of the world's population uses natural remedies, especially in poorer nations. When conventional treatments have failed, it may make sense to use natural drugs for the treatment of pathologic oral dental disorders, as they are readily available, inexpensive, and have few negative effects. The purpose of this article is to provide a comprehensive analysis of the benefits and applications of natural biomaterials in dentistry, to gather relevant information from the medical literature with an eye toward its practical applicability, and make suggestions for the directions for future study.

Evaluation of Knowledge and Practice of Resident Dentists in Iasi, Romania in the Management of Traumatic Dental Injuries: A Cross-Sectional Study.

Dentists play an essential role in the treatment of dental and periodontal traumatic injuries by providing early and correct treatment. The purpose of the present study was to assess the level of knowledge of dental residents regarding dental trauma. The cross-sectional study was conducted at the Faculty of Dental Medicine within the "Grigore T. Popa" University of Medicine and Pharmacy in Iasi, Romania on a sample of 366 residents in General Dentistry, Pediatric Dentistry and Periodontology. To assess their knowledge, a questionnaire was created containing 18 questions about the clinical signs and therapy of dental trauma, with a focus on tooth avulsion. A very low level of knowledge (<25%) was found only for the type of splinting required to maintain an avulsed tooth on the arch. The highest number of correct answers was provided by the residents in Periodontology. Physiological serum as storage medium was recognized by a percentage of 75.9-80% of the subjects, and 60-77% of them recognized pulp necrosis as complication of dental avulsion. The study underlines the need to introduce in the curriculum of all categories of residents additional information, not only in the already existent theoretical form, but also as possible scenarios of various clinical situations.

The Role and Involvement of Stem Cells in Periodontology.

Periodontitis is a widespread inflammatory condition, characterized by a progressive deterioration of the supporting structures of the teeth. Due to the complexity of periodontal tissue and the surrounding inflammatory microenvironment, the repair of lesions at this level represents a continuous challenge. The regeneration of periodontal tissues is considered a promising strategy. Stem cells have remarkable properties, such as immunomodulatory potential, proliferation, migration, and multilineage differentiation. Thus, they can be used to repair tissue damage and reduce inflammation, potentially leading to periodontal regeneration. Among the stem cells used for periodontal regeneration, we studied dental mesenchymal stem cells (DMSCs), non-dental stem cells, and induced pluripotent stem cells (IPSCs). Although these cells have well documented important physiological characteristics, their use in contemporary practice to repair the affected periodontium is still a challenge.

Perception of Remote Learning by Fixed Prosthodontic Students at a Romanian Faculty of Dentistry.

The COVID-19 pandemic has forced the transfer of traditional on-site educational activities to the online environment. This study aimed to evaluate the perception and acceptance of remote learning among fixed prosthodontic students attending the Faculty of Dental Medicine of "Grigore T. Popa" University of Medicine and Pharmacy in Iasi, Romania, and to analyze the feedback regarding their experience with the new online methods, the perceived quality thereof and suggestions for improvement. An observational cross-sectional, online study based on 22 questions was conducted with 259 students. The general opinion of online education was good or very good (40.15%); regarding its efficiency, 28.57% found it efficient while 34.36% found it inefficient or very inefficient; regarding the pleasure of learning online, 45.95% of students enjoyed online learning, while 36.64% did not enjoy it. The problem that was most cited by respondents was that of keeping all students motivated and involved (65.6%). Sixty-two percent of the respondents believe that online dental education should not exist, or just to a small extent, a result justified by the practical nature of the profession. The general opinion was that health risks should be managed and mitigated by using a hybrid system that would allow students to do on-site clinical training with direct contact with patients.

The Involvement of Photobiology in Contemporary Dentistry-A Narrative Review.

Light is an emerging treatment approach that is being used to treat many diseases and conditions such as pain, inflammation, and wound healing. The light used in dental therapy generally lies in visible and invisible spectral regions. Despite many positive results in the treatment of different conditions, this therapy still faces some skepticism, which has prevented its widespread adoption in clinics. The main reason for this skepticism is the lack of comprehensive information about the molecular, cellular, and tissular mechanisms of action, which underpin the positive effects of phototherapy. However, there is currently promising evidence in support of the use of light therapy across a spectrum of oral hard and soft tissues, as well as in a variety of important dental subspecialties, such as endodontics, periodontics, orthodontics, and maxillofacial surgery. The merging of diagnostic and therapeutic light procedures is also seen as a promising area for future expansion. In the next decade, several light technologies are foreseen as becoming integral parts of modern dentistry practice.

Various Surgical Interventions in Treating Odontogenic Keratocyst: A Radiological Case Report.

The odontogenic keratocyst (OKC) is among the most aggressive odontogenic cysts because of its high recurrent rate. This study's objective was to describe a 7-year radiological and clinical follow-up of an OKC with two recurrences and a combination of surgical treatments. The cyst contents were drained at the biopsy to allow decompression, and then marsupialization (Partsch I) was carried out with good results. In the following two years, the endodontic and radiological evaluation of the neighboring teeth indicated endodontic avoidance. The remaining OKC enucleation (Partsch II) with chemical curettage and suture was performed two years after the first presentation, and the multifocal recurrences developed were also treated by enucleation and chemical curettage. At the last radiological follow-up, no recurrence was evident. Based on our experience, we concluded that patients diagnosed with a OKC should be radiologically evaluated at least once a year for at least 7 years, the endodontic diagnosis and treatment of neighboring teeth should be performed as early as possible, and the combination of surgical treatment and the long follow-up period is challenging.

Microbial Removal of Heavy Metals from Contaminated Environments Using Metal-Resistant Indigenous Strains.

Contamination of soil with heavy metals has become a matter of global importance due to its impact on agriculture, environmental integrity, and therefore human health and safety. Several microbial strains isolated from soil contaminated by long-term chemical and petrochemical activities were found to manifest various levels of tolerance to Cr, Pb, and Zn, out of which Bacillus marisflavi and Trichoderma longibrachiatum exhibited above-moderate tolerance. The concentrations of target heavy metals before and after bioremediation were determined using electrochemical screen-printed electrodes (SPE) modified with different nanomaterials. The morpho-structural SEM/EDX analyses confirmed the presence of metal ions on the surface of the cell, with metal uptake being mediated by biosorption with hydroxyl, carboxyl, and amino groups as per FTIR observations. T. longibrachiatum was observed to pose a higher bioremediation potential compared to B. marisflavi, removing 87% of Cr and 67% of Zn, respectively. Conversely, B. marisflavi removed 86% of Pb from the solution, compared to 48% by T. longibrachiatum. Therefore, the fungal strain T. longibrachiatum could represent a viable option for Cr and Zn bioremediation strategies, whereas the bacterial strain B. marisflavi may be used in Pb bioremediation applications.

A Comparative Analysis of Dental Measurements in Physical and Digital Orthodontic Case Study Models.

Background and Objectives: Study models are essential tools used in the dental teaching process. The aim of the present study was to compare the values obtained by manual and digital orthodontic measurements on physical and digital case study models. Materials and Methods: The physical experimental models were obtained by traditional pouring (improved stone-type IV gypsum products) and by additive manufacturing (resins). The digital experimental models were created by scanning the physical ones, using a white light-emitting diode (LED) source and an L-shaped dental scanner­Swing DOF (DOF, Seoul, Korea). The physical study models were first measured using a digital caliper, and then, they were scanned and evaluated using the DentalCad 3.0 Galway software (exocad GmbH, Darmstadt, Germany). The Pont, Linder−Harth, and Bolton indices, which are used in orthodontics for training students, were derived using the available data. Results: When comparing the linear measurement mean ranks taken on physical study models to those of digital models, no statistically significant differences (p > 0.05) were found. A similar result was also shown when the dentoalveolar growth indicators were analyzed. Conclusions: It can be concluded that dental study models made by direct light processing (DLP) and pouring type IV class gypsum are both acceptable for orthodontic teaching purposes.

Odontogenic Sinusitis: From Diagnosis to Treatment Possibilities-A Narrative Review of Recent Data.

The maxillary sinus is a structure at the border of specialties: otorhinolaryngology and maxillofacial surgery. Due to this fact, regarding etiology, it can be affected by both the rhinogenic and odontogenic path and can impose diagnostic difficulties. The etiopathogenic mechanisms that can affect the Schneiderian membrane are mainly inflammatory, iatrogenic, traumatic, and tumorous in nature. From a microbiological point of view, the bacteriology is polymorphic, including both aerobic and anaerobic species in acute OS, the predominating species in acute OS being aerobic, and in chronic anaerobic germs. The role of fungi in the determination of this pathology and in the production of the biofilm that leads to resistance to antibiotic treatment is also discussed. The present paper aims to present the etiopathogenesis, bacteriology, clinical manifestations, as well as treatment of odontogenic sinusitis (OS) from an updated perspective through reviewing the literature. If unilateral maxillary sinusitis is usually due to odontogenic causes, this does not clinically exclude the possibility of strictly rhinogenic causes in the occurrence of sinusitis. This underlines the important role of complex oral and rhinological clinical examination as well as the role of preclinical examinations in specifying the certainty diagnosis. Simple radiography, orthopantomography, CT, and CBCT are compared in terms of diagnostic accuracy. The treatment of OS is complex, involving medication, dental, and surgical measures. The value of endoscopic surgery is emphasized, comparing its advantages over the classic Caldwell-Luc technique.

The Effects of 810 nm Diode Laser and Indocyanine Green on Periodontal Parameters and HbA1c in Patients with Periodontitis and Type II Diabetes Mellitus: A Randomized Controlled Study.

The aim of this study was to investigate the effects of adjunctive periodontal therapy of 5 mg/mL indocyanine green irradiation by an 810 nm diode laser (aPDT), supplementary to scaling and root planing (SRP) in patients with periodontitis and type II diabetes mellitus (DM) compared to the SRP alone, on periodontal clinical parameters and glycated hemoglobin A1c (HbA1c). The study was conducted on 49 subjects with type II DM and periodontitis, divided into two groups: the SRP group (n = 25), who followed SRP alone, and the SRP + aPDT group (n = 24), who followed SRP and four weekly sessions of indocyanine green irradiation by an 810 nm diode laser. Plaque Index (PI), Bleeding on Probing Index (BOP), probing depth (PD), clinical attachment loss (CAL) and HbA1c were investigated at baseline and after 6 months. At 6 months, both SRP alone and SRP + aPDT generated significant reductions in all the investigated parameters; SRP + aPDT produced more significant reductions for BOP, PD and CAL (p < 0.001) but not for PI and HbA1c, than SRP alone. aPDT with indocyanine green therapy was well tolerated, with two subjects reporting slight discomfort. Therefore, aPDT with indocyanine green might represent a good adjunctive periodontal treatment option for SRP in patients with type II DM and periodontitis.

Knowledge, Practice, and Awareness of Oral Cancer and HPV Infection among Dental Students and Residents: A Cross-Sectional Study.

Background and Objectives: Dentists play a very important part in the early identification of oral cancer lesions. This aspect of dental practice depends on the knowledge acquired during the faculty years. The aim of this study was to assess dental students' and residents' levels of awareness in terms of oral cancer. Materials and Methods: The cross-sectional study was conducted at the Faculty of Dental Medicine within the "Grigore T. Popa" University of Medicine and Pharmacy in Iasi, on a sample of 197 students in the fourth and the fifth years and first year residents in general dentistry. To assess their knowledge, a questionnaire was created containing 22 questions about the risk factors for oral cancer, with a focus on HPV infection. Results: Most participants correctly identified smoking, alcohol, and the HPV infection as risk factors and leukoplakia and erythroplasia as potentially malignant lesions. At the opposite site, aspects considered as unsatisfactory focused on the palpation of lymphatic nodules, a procedure largely carried out by 41.6% of the fourth year students, the counseling only of the patients at risk performed by 59.7% of residents, the lack of knowledge about the prevention of oral cancer through anti-HPV immunization found in 39.7% of the fifth year students. Other incorrect answers focused on other types of suspicious lesions, such as actinic cheilitis, as well as certain areas in the oral cavity subject to the frequent onset of oral cancer, such as buccal mucosa. Conclusions: Although the fifth year students and residents have better knowledge than the fourth year students, the gaps in terms of knowledge and practice encountered in all three categories of participants require a reevaluation of the academic curriculum and the focus on the building of the skills necessary for the correct screening of oral cancer.

An Interdisciplinary Study Regarding the Characteristics of Dental Resins Used for Temporary Bridges.

Background and Objectives: The surface condition of the materials that are used for temporary prostheses influences their microbial colonization, with a direct impact on the oral tissues. This study aims at a comparative analysis of three types of resins for temporary bridges using conventional and digital technologies. The attention was focused on the analysis of the surface characteristics and mechanical strength of these materials. Materials and Methods: The surface condition was assessed for three distinct materials both before and after polishing- heat-curing resin Superpont C + B (SpofaDental, Jicin, Czech Republic) used unconventional technology, Zotion dental milling polymethyl methacrylate (PMMA) block (Zotion, Chongqing, China) for provisional crowns/bridges used in digital subtractive technologies and Freeprint Temp (Detax GmbH & Co. KG, Ettlingen, Germany) resin for temporary crowns and bridges that are used in 3D printing technologies. The two-way ANOVA analysis indicated that polishing leads to a statistically significant increase in roughness coefficients for all the three resins that were tested (p < 0.001). While the highest roughness coefficients were displayed in the 3D cured sample, the largest decrease was reported by the milled sample Results: The results revealed that surface roughness was significantly influenced by both the type of resin that was used (p < 0.001) and the treatment that was induced by finishing and polishing (p < 0.001). Similar p-values were obtained for each of the three resins. Conclusions: The results demonstrated a significant optimization of the surfaces after finishing and polishing and statistically significant differences between the surface parameters and the mechanical properties of the samples. The low values of the roughness and the acceptable values of the mechanical resistance for the conventional samples indicate these materials for the long-term temporary bridge's realization, allowing the correct restoration of the functions and the rehabilitation at the oral level.

Effects of Locally Delivered Minocycline Microspheres in Postmenopausal Female Patients with Periodontitis: A Clinical and Microbiological Study.

The postmenopausal period, due to low hormonal concentrations, can exert a negative influence on both periodontitis and osteoporosis evolution. The present study aimed to identify potential clinical and microbiological benefic effects of locally delivered minocycline microspheres (Arestin®) in post-menopausal female patients with moderate and severe periodontitis. Probing depth, clinical attachment levels and bleeding on probing index, along with BANA tests for Porphyromonas gingivalis, Tannerella forsythia, and Treponema denticola, were performed before and at 3 months after a combined treatment of scaling, root planing (SRP), and Arestin® placed in deep periodontal pockets. The association between SRP and Arestin® exerted significant improvements in terms of clinical periodontal parameters, as well as significant reductions in the red complex bacteria detection.

Esthetic Rehabilitation Through CAD/CAM Technology - Case Report.

With the progress of dental materials and techniques, CAD/CAM system currently allows the manufacture of high precision prosthetic restorations. Zirconia is an ideal base for porcelain because the bonding process between the zirconia and the porcelain is stronger than it is with porcelain and metal. This means that the porcelain is less likely to fracture away from a zirconia base. Zirconia can also be colored to match teeth and it is translucent, mimicking the natural look of teeth far better than any crown with a metal base could. The aim of this article is to describe a case of oral rehabilitation, involving CAD/ CAM technology for full dental crowns, using zirconia as framework.

[Toric intraocular lens implantation in cataract patients--6 months results]. / Implantarea cristalinului artificial toric la pacientii cu cataracta. Rezultate la 6 luni.

UNLABELLED: The purpose of this paper is to evidence the advantages of artificial Acrysof Toric IOL implantation in patients with cataract and corneal astigmatism. MATERIAL AND METHODS: Prospective clinical study on 30 patients with cataract operated on with phacoemulsification and implantation of Acrysof Toric IOL on 32 eyes, between September 2007- March 2008. RESULTS: The predictability between estimated and obtained astigmatism is 96.87%. In most of the cases the IOL was well centered in the capsular bag and stable on the predetermined axis, in 1 eye the IOL was rotated with about 30 degrees. The astigmatism evaluated in all patients at 6 months postoperatively being corrected in 78.13% of cases and reduced in 21.87% of cases. The UCVA between 2/3-5/5 was in 65.63% of cases and BCVA was in 34.37% of cases. To mention that 63.63% of patients with BCVA wanted to remain with myopia. CONCLUSIONS: Phacoemulsification and Acrysof Toric IOL implantation are an attractive alternative for patients with cataract and corneal astigmatism. The Acrysof Toric IOL eliminates or reduces preoperatively astigmatism, providing many patients a clear distance vision without glasses.

Molecular mechanisms underlying anti-inflammatory phenotype of neonatal splenic macrophages.

Neonatal humans and rodents are susceptible to infection with encapsulated bacteria as a result of an inability to make antibodies to capsular polysaccharides. This is partly a result of decreased production of proinflammatory cytokines by splenic macrophages (MPhi) from neonates. In this study, we show that when stimulated with a variety of agonists to TLR2, -4, and -9, neonatal MPhi make less proinflammatory cytokines and more IL-10 than adult MPhi. IL-10 appears to have a role in the decreased proinflammatory cytokine production, as neonatal MPhi treated with anti-IL-10 receptor antibody or from IL-10(-/-) mice produced levels of proinflammatory cytokines at a level comparable with that produced by adult MPhi. A microarray analysis of RNA from resting and LPS-stimulated MPhi from neonatal and adult mice showed that expression of a large number of genes encoding cytokines, chemokines, and their receptors was decreased dramatically in the neonatal MPhi, although some cytokines, including IL-10 and IL-16, were enhanced. Several genes in the TLR signaling pathway leading to NF-kappaB activation were down-regulated, which may account for the decreased chemokine and cytokine synthesis. It is surprising that p38alpha MAPK, known to be required for TLR-induced cytokine secretion, was enhanced in the neonatal MPhi. Our studies with the p38 MAPK inhibitor SB203580 suggested that excess p38 MAPK activity can be inhibitory for TLR2-, -4-, and -9-induced production of proinflammatory cytokines but not IL-10. The anti-inflammatory phenotype of the neonatal Mphi may be unique to the developing organism, although it compromises the neonate's ability to respond to encapsulated bacteria.

[Our experience with Acrysof Natural intraocular lens]. / Experienta noastra în implantarea cristalinelor artificiale Acrysof Natural.

UNLABELLED: The purpose of this paper is to appreciate the Acrysof Natural IOL comportment during the implantation after phacoemulsification, and to evaluate the visual acuity at 2 months and 2 years postoperative. MATERIAL AND METHODS: Prospective clinical study which comprises 48 patients( 48 eyes) with cataract operated on with phacoemulsification and implantation of Acrysof Natural IOL with the Monarch II injector and the implantation forceps. RESULTS: The patients' age was between 4- 82 years; The IOLs were introduced with the Monarch II injector in 47 cases and with the implantation forceps in 1 case; No IOL was damaged during the implantation; The unfolding and the rotation of the IOL were possible in all cases, without incidents; The visual acuity appreciated 2 months and 2 years postoperative was good in the most of the cases; the chromophore pigment did not influence the quality of vision and the color perception. CONCLUSIONS: The implantation of the Acrysof Natural IOL is identical with the implantation of the Acrysof single piece IOL, is easy to perform and completely atraumatic.

[Mechanisms of laser photocoagulation in diabetic retinopathy]. / Mecanismele fotocoagularii laser în retinopatia diabetica.

The aim of laser photocoagulation in diabetic retinopathy is to stop the development of retinal neovessels and even to determine their involution. Early applied, laser photocoagulation can significantly reduce the risk of severe visual loss. The knowledge of the multiple mechanisms of laser photocoagulation leads to the possibility to introduce a well dosed treatment that is appropriate for the clinical stage of the retinopathy.

Molecular basis of age-associated cytokine dysregulation in LPS-stimulated macrophages.

Aged humans and rodents are susceptible to infection with Streptococcus pneumoniae bacteria as a result of an inability to make antibodies to capsular polysaccharides. This is partly a result of decreased production of proinflammatory cytokines and increased production of interleukin (IL)-10 by macrophages (Mphi) from aged mice. To understand the molecular basis of cytokine dysregulation in aged mouse Mphi, a microarray analysis was performed on RNA from resting and lipopolysaccharide (LPS)-stimulated Mphi from aged and control mice using the Affymetrix Mouse Genome 430 2.0 gene chip. Two-way ANOVA analysis demonstrated that at an overall P < 0.01 level, 853 genes were regulated by LPS (169 in only the young, 184 in only the aged, and 500 in both). Expression analysis of systematic explorer revealed that immune response (proinflammatory chemokines, cytokines, and their receptors) and signal transduction genes were specifically reduced in aged mouse Mphi. Accordingly, expression of Il1 and Il6 was reduced, and Il10 was increased, confirming our previous results. There was also decreased expression of interferon-gamma. Genes in the Toll-like receptor-signaling pathway leading to nuclear factor-kappaB activation were also down-regulated but IL-1 receptor-associated kinase 3, a negative regulator of this pathway, was increased in aged mice. An increase in expression of the gene for p38 mitogen-activated protein kinase (MAPK) was observed with a corresponding increase in protein expression and enzyme activity confirmed by Western blotting. Low doses of a p38 MAPK inhibitor (SB203580) enhanced proinflammatory cytokine production by Mphi and reduced IL-10 levels, indicating that increased p38 MAPK activity has a role in cytokine dysregulation in the aged mouse Mphi.