Hasil untuk "Dentistry"

C. Misch

Li Zhou, Qing Liu, Zehui Fang et al.

The single-function agents with wide-spectrum activity which tend to disturb the ecological balance of oral cavity cannot satisfy dental treatment need. A multi-functional agent with specifically targeted killing property and in situ remineralization is warranted for caries management. A novel multi-functional agent (8DSS-C8-P-113) consisting of three domains, i.e., a non-specific antimicrobial peptide (AMP) (P-113), a competence stimulating peptide (C8), and an enhancing remineralization domain (8DSS), is fabricated and evaluated in this study. The findings demonstrates that 2 μM mL−1 of 8DSS-C8-P-113 eliminates planktonic Streptococcus mutans (S. mutans) without disrupting the oral normal flora. At a concentration of 8 μM mL−1, it exhibits the ability to prevent S. mutans' adhesion. Furthermore, 8DSS-C8-P-113 self-assembles a hydrogel state at the higher concentration of 16 μM mL−1. This hydrogel self-adheres on the tooth surface, resisting acid attack, eradicating S. mutans’ biofilm, and inducing mineralization in order to facilitate the repair of demineralized dental hard tissue. Its significant effectiveness in reducing the severity of dental caries is also demonstrated in vivo in a rat model. This study suggests that the multi-functional bioactive AMP 8DSS-C8-P-113 is a promising agent to specifically target pathogen, prevent tooth demineralization, and effectively induce in situ bio-mimic remineralization for the management of dental caries.

Jiu Lin, Chen Qianming

Aim or purpose: Kir4.1 emerged as a novel therapeutic target for nervous system diseases, such as depression. However, the role and mechanism of Kir4.1 in peripheral and central sensitization after trigeminal neuropathic pain is still unclear. Materials and methods: A chronic constriction injury of the infraorbital nerve (CCI-ION) model was established, and orofacial mechanical hypersensitivity was assessed using the Von Frey test. Immunofluorescence was performed to detect ATF3, c-Fos, GFAP, and Kir4.1 in the trigeminal ganglion (TG) and spinal trigeminal subnucleus caudalis (SpVc). AAV2/8-mediated knockdown or overexpression of Kir4.1 was conducted in TG and SpVc of WT and Kir4.1f/f mice. RT-qPCR and western blot were used to analyze the expression of Kir4.1 and its downstream signaling molecules. Experiments were approved by the Zhejiang University School of Medicine. Results: CCI-ION induced orofacial hypersensitivity and upregulated ATF3 in TG and c-Fos in SpVc, confirming trigeminal nerve injury. Kir4.1 was predominantly expressed in satellite glial cells (SGCs) of TG and astrocytes of SpVc. CCI-ION downregulated Kir4.1, GLAST, and GLT-1 while upregulating BDNF and GDNF in TG and SpVc. Kir4.1 knockdown in SGCs or astrocytes exacerbated pain hypersensitivity, decreased GLAST and GLT-1, and increased BDNF and GDNF expression. Conversely, Kir4.1 overexpression alleviated pain hypersensitivity and reversed these molecular changes. Conclusions: Kir4.1 in SGCs and astrocytes regulates neurotrophic factors (BDNF, GDNF) and glutamate transporters (GLAST, GLT-1), suggesting Kir4.1 as a potential therapeutic target for trigeminal neuropathic pain.

Heidi Saad Refaey, Sanaa H. Abdelkader, Yasser M. Aly

Abstract Background Conservative dentistry introduced modern restoration designs, contributing to the greater use of partial-coverage ceramic restorations. New strong bondable ceramic materials made fabricating partial coverage ceramic restorations easier to restore the badly destructed teeth. Aim of the study This study investigated the impact of three distinct overlay preparation designs on the marginal fit (both before and after thermal aging) and the fracture resistance of overlay restorations fabricated using advanced zirconia-reinforced lithium disilicate (ALD) CAD/CAM glass-ceramic blocks. Materials and methods Using a standardized preparation protocol, three typodont molars were prepared to receive three different indirect overlay ceramic restoration designs. The typodont teeth were duplicated to get 27 resin dies that were randomly allocated into three groups (n = 9) based on the preparation design; group (O): a traditional overlay preparation with anatomical occlusal reduction, group (OS): anatomical occlusal reduction with circumferential shoulder finish line, and group (OG): anatomical occlusal reduction with a central groove preparation at the mid-occlusal surface. After standardized restorations fabricated following the manufacturer’s guidelines, the restorations were cemented to their corresponding dies and exposed to thermal aging corresponding to 6-month clinical service. Marginal gap was measured before and after thermal aging procedure using an optical microscope. To measure fracture resistance, specimens were loaded till failure using the universal testing machine. The Kruskal Wallis test was utilized to assess data among the groups, followed by Dunn’s post hoc test with Bonferroni correction. Differences in the marginal fit before and after thermal aging were evaluated using Wilcoxon Sign Rank test. Results A statistically significant difference in marginal fit was observed between the studied groups, with a p-value of 0.032 where group OS has the lowest micro gap compared to group OG and group O. The fracture resistance group (O) recorded the highest fracture resistance with a statistically significant difference between the studied groups at p value = 0.043. Conclusions Adjusting the tooth preparation significantly influenced both the fracture resistance load and the marginal fit observed for advanced zirconia-reinforced lithium disilicate glass-ceramic (ALD) overlays.

Isha Duggal, Tulika Tripathi

In the current technological era, dental practitioners are faced with various ethical challenges, highlighting the importance of bioethics in this healthcare discipline. The rise of artificial intelligence has recently sparked a debate regarding the privacy of patient data. While the advancements may offer innovative treatment options, their long-term effects may not be fully understood, raising questions about the responsible implementation of such methods. Thus, conscientious and ethical AI use in dentistry encompasses that patients be notified about how their data is used and also about the involvement of AI-based decision-making. This paper explores the key bioethical considerations in dental healthcare, with a focus on evidence-based AI development and use. The framework of ethical principles and guidelines provided would foster trust between the clinician and patients, while promoting the highest standards of care.

Ricardo D. Coletta, Ali-Farid Safi, Arnab Pal et al.

Ika Devi, Erliera Sufarnap, Finna et al.

Background: Chitosan has an antimicrobial effect in oral hygiene control. Orthodontists sometimes prescribe mouthwash to adolescent patients. Copper-nickel-titanium (CuNiTi) orthodontic archwire is widely used in orthodontic treatment. Chitosan’s effects on the CuNiTi properties of orthodontic archwire are not generally known. Purpose: This study aimed to measure the acidity, copper ion release, deflection, and surface roughness of CuNiTi orthodontic archwire immersed in artificial saliva and 2% chitosan. Methods: This study comprised experimental laboratory research. Forty-two CuNiTi orthodontic archwires were divided into three groups. Group A consisted of 18 archwires immersed in artificial saliva, Group B consisted of 18 archwires immersed in 2% chitosan, and Group C was six archwires for the baseline sample. The two intervention groups (A and B) were divided into three subgroups of six samples and were subjected to different immersion times—i.e., two, four, and six weeks. Acidity, copper ion release, deflection, and surface roughness were measured using pH meters, atomic absorption spectrophotometry (AAS), a universal testing machine (UTM), and a scanning electron microscope (SEM). Results: The results showed that Group A was more alkaline than Group B, and it was significantly different only in Week 2. Group B’s copper ion release was significantly lower than Group A for all the time observations (p<0.05), and the deflection analysis showed no significant difference in any of the groups (p>0.05). Furthermore, the SEM images showed CuNiTi in Group A at Week-6 had the most porosities and defects. Conclusion: The chitosan produces buffer effects on the pH; it also exhibits lower copper ion release, no differences in unloading forces, and subjectively has better surface roughness.

Shaymaa Ali Abdul-Razzaq, Muna Saleem Khalaf

Introduction: The objective of this study was to evaluate the impact of chitosan nanoparticles’ pretreatment of dentin surface on the macro shear bond strength of resin composite, both immediately and over an extended period. Methods: Thirty caries-free, unrestored human premolars were randomly assigned to six study groups. The dentin surface of the intervention groups underwent pretreatment with 0.2% chitosan and 0.05% NaF solutions for 1 minute. A standard etch-and-rinse adhesive procedure was performed for all the study groups. After 24 hours, half of the specimens underwent a macro shear bond strength test at a crosshead speed of 1 mm/min, whereas the other specimens underwent the same procedure after 300 thermal cycles between 5 and 55°C with a 30-second dwell time in the thermocycling device. Results: The study found that the type of dentin surface treatment agents did not significantly affect the shear bond strength (P = 0.52). However, there were statistically significant differences between immediate and prolonged shear bond strength in the chitosan (P < 0.01) and the control groups (P = 0.005). On the other hand, there were no significant differences between the immediate and prolonged shear bond strength in the NaF group (P = 0.997). Conclusion: Dentin pretreatment with 0.2% chitosan solution did not significantly affect the shear bond strength of the etch-and-rinse adhesive system. Pretreatment with NaF maintained the shear bond strength of the adhesive to dentin after 300 thermal cycles.

M. Casale, A. Moffa, P. Vella et al.

Inês E. Dias, Carlos A. Viegas, João F. Requicha et al.

Mesenchymal stem cells (MSCs) are multipotent cells, defined by their ability to self-renew, while maintaining the capacity to differentiate into different cellular lineages, presumably from their own germinal layer. MSCs therapy is based on its anti-inflammatory, immunomodulatory, and regenerative potential. Firstly, they can differentiate into the target cell type, allowing them to regenerate the damaged area. Secondly, they have a great immunomodulatory capacity through paracrine effects (by secreting several cytokines and growth factors to adjacent cells) and by cell-to-cell contact, leading to vascularization, cellular proliferation in wounded tissues, and reducing inflammation. Currently, MSCs are being widely investigated for numerous tissue engineering and regenerative medicine applications. Appropriate animal models are crucial for the development and evaluation of regenerative medicine-based treatments and eventual treatments for debilitating diseases with the hope of application in upcoming human clinical trials. Here, we summarize the latest research focused on studying the biological and therapeutic potential of MSCs in the goat model, namely in the fields of orthopedics, dermatology, ophthalmology, dentistry, pneumology, cardiology, and urology fields.

Brauer, Delia S., Hupa, Leena

Bioactive glasses were the first synthetic materials to bond to human body tissue, making them ideal for replacing and regenerating bone. Since their first development over half a century ago, many new bioactive glass compositions have been developed for medicine and dentistry. This paper looks at different design strategies employed over the years as well as aspects of glass structure relevant to optimising bioactive glass performance. Statistical compositional series allowed for getting an overview of various compositions and their properties. Since the improvement of structural analysis techniques, particularly solid-state NMR, we can directly relate several bioactive glass properties to the atomic structure, i.e. the spatial arrangement of atoms. Such detailed understanding of the impact of composition and structure on bioactive glass properties enables us to minimise the number of compositions in preclinical and clinical tests needed to confirm positive tissue responses.

Masaru Murata, Md Arafat Kabir, Yukito Hirose et al.

The aim of this clinical case study was to observe biopsy tissues at 5 months after an autograft of a partially demineralized dentin/cementum matrix (pDDM) into a tooth-extracted socket exhibiting healing failure. A 66-year-old female presented with healing failure in the cavity for 2 months after the extraction (#36). Initial X-ray photos showed a clear remainder of lamina dura (#36), a residual root (#37), and a horizontal impaction (#38). The vital tooth (#38) was selected for pDDM. The third molar crushed by electric mill was decalcified in 1.0 L of 2.0% HNO₃ for 20 min and rinsed in cold distilled water. The pDDM granules (size: 0.5–2.0 mm) were grafted immediately into the treated socket. X-ray views just after pDDM graft showed radio-opaque granules. At 5 months after pDDM graft, the surface of regenerated bone was harmonized with the mandibular line, and bone-like radio-opacity was found in the graft region. The biopsy tissue (diameter: 3.0 mm) at 5 months after pDDM graft showed that mature bone was interconnected with the remaining pDDM. The novel histological evidence highlighted that newly formed bone was connected directly with both dentin-area and cementum-area matrix of pDDM. We concluded that pDDM contributed to the regeneration of bone in the unhealed socket, and this regeneration prepared the socket for implant placement. Autogenous pDDM could be immediately recycled as an innovative biomaterial for local bone regeneration.

G. Pellegrini, L. Francetti, B. Barbaro et al.

Survival, differentiation capability, and activity of cells are strictly related to structural features and the composition of the extracellular matrix, and its variation affects tissue homeostasis. Placement of a dental implant in bone tissue activates a sequence of molecular and cellular events that lead to the apposition of newly-formed bone directly onto the titanium surface. Due to implant's interaction with the mineralized tissue, osseointegration is affected by the surface structure of the implanted material. Surface nanotopography and microtopography can modify the shape and activity of mesenchymal stem cells leading to a higher differentiation rate of these cells into osteogenic lineage with the upregulation of osteoblastic genes. Several approaches for implant surface modification are currently under investigation or have been recently proposed to improve osseointegration. Most surface treatments are aimed at the formation of a thick layer of titanium oxide, at the alteration of surface chemical composition by incorporating bioactive molecules and drugs, and at the creation of a surface topography that is more attractive for osteoblast differentiation, adhesion, and osteogenic activity. Data on the cellular-substrate interaction, as well as in vivo studies assessing the response to these novel surfaces, are reviewed in the present study. The application of modern surfaces in dental clinical practice might increase and accelerate implant osseointegration, but could also reduce the occurrence of peri-implant bone loss and favor the re-osseointegration of an affected surface.

E. T. Carrera, H. B. Dias, S. T. Corbi et al.

A. Hanif, S. Qureshi, Z. Sheikh et al.

ABSTRACT After tooth loss, an individual may seek tooth replacement so that his/her function and esthetics could be restored. Clinical prosthodontics, during the past decade, has significantly improved and developed according to the advancements in the science and patient's demands and needs. Conventional options in prosthodontics for substituting a missing single tooth include the removable partial denture, partial and full coverage bridgework, and resin-bonded bridgework. Dental implants have gained increasing popularity over the years as they are capable of restoring the function to near normal in both partial and completely edentulous arches. With substantial evidence available, fixed implant-supported prosthesis are fully acknowledged as a reliable treatment option for the replacement of single or multiple missing teeth nowadays. While dental implants are increasingly becoming the choice of replacement for missing teeth, the impediments associated with them are progressively emerging too.

B. Vandenberghe

Dental imaging has seen a rapid technological advance over the last several years. Not only has most x-ray based diagnostic technology been digitized, with the possibility of low dose 3D computed tomography imaging, but many novel optical imaging techniques have now also been adopted in a more therapeutic imaging of the dental patient. When combining and manipulating such different digital image data, clinicians can now easily plan and simulate treatments on-screen, use 3D printed models and aids to assist in accurate transfer of the virtual planning or even follow-up their treatments over time. However, it seems that knowledge on digital technology is still lacking in clinical practice, which may contribute to errors or slow adoption. The purpose of this article is to bring an overview of the digitalization of dental imaging techniques and inform dental professionals on the digital tools that are available for the follow-up of patient treatments.

Harleen Bali, Vaibhav Rai, Nitin Khanduri et al.

Introduction: Medical school is recognized as a stressful environment that may have a negative effect on a student’s academic performance, health, and psychosocial well-being. This could further impact future health professionals’ attitudes and compromise patients’ care. This study aims to find out various sources of stress for medical and dental students to help prevent many future health problems in a student’s life. Methods: It was a cross-sectional study done in Universal College of Medical Sciences, Bhairhawa, Nepal, among undergraduate final year bachelor of medicine and bachelor of surgery and third and fourth year (phase I and phase II) dental students, using a questionnaire with Likert’s scale. Data obtained was tabulated and analyzed using analysis of variance. Results: Results showed that stress during exam 210 (92.9%) and preparation phase 200 (88.5%) stood out as the maximum stressors for our study group. The least stress-causing element was recorded as terms with seniors 45 (19.9%), adjustment with roommates 52 (23.01%), and competing with peers 69 (30.53%). Length of course 187 (82.74%), understanding the course 173 (76.55%), reading several textbooks 171 (75.66%), and work overload 165 (73.01%) amounted to significant stressors. Conclusions: Stress has a detrimental effect both on health as well as academic performance. The stressors at the campus should be identified and proper coping assistance should be provided to individual students. Systemic efforts are needed to address their concerns and make mental health care easily accessible to them. Counseling and awareness are recommended.

Eman Al Mheiri, Jahanzeb Chaudhry, Salma Abdo et al.

Abstract Background The aim of this study was to analyze the root and canal morphology of the maxillary permanent first molars in an Emirati population using cone-beam computed tomography (CBCT). Methods Two hundred and sixty-one CBCT scans were acquired. The data were extracted and anonymized to remove all patient identifiers. Two observers (an endodontic resident and an endodontist) evaluated all scans on diagnostic quality monitors. Results The prevalence of a second mesiobuccal canal (MB2) was 80.1% in all examined samples. Type II Vertucci classification, was the most common canal configuration (59%) in the mesiobuccal root, followed by Types I (19.9%) and IV (15.3%), while Type III was the least common (5.7%). Types I, II, and IV were significantly more common in the 21–40-year age group (P < 0.001), while Type III was observed significantly more often in the < 20-year age group (P < 0.001). No significant effect of gender on the prevalence of Vertucci classification in the mesiobuccal root of maxillary first molars (P = 0.74) was found. Analysis of bilateral symmetry showed that 80% teeth had perfect bilateral symmetry, whereas 20% were asymmetrical. Type II canal configuration showed the highest prevalence of bilateral symmetry (48.7%), followed by Type I (15%) and Type IV (10%), while Type III showed the least prevalence of symmetry (3%). Conclusions This was the first study to analyze the prevalence of MB2 canal in an Emirati population. Our results indicate high prevalence of MB2 (80.1%) and emphasize the importance of using advanced techniques to locate the MB2 canal.

M. Kmiec, L. Pighinelli, Tedesco Mf et al.

Biomaterials are those non-living materials used in the medical, biomedical and other fields, aiming to interact with the biological system [1]. Many of these materials, such as chitosan, are used as effective alternatives for the replacement of tissues, including bone tissue, since they do not present risks of disease transmission or immune rejection, as well as unlimited availability and low cost [2]. Recently, several researches have been carried out aiming at new materials capable of being associated with other substances that promote bone formation, especially biopolymers, in particular chitosan, which presents great potential in the repair of bone defects, in relation to the limitations of other biomaterials [3].

S. Hu, B. Meyer, M. S. Duggal