Fiber post bonding with beta-tricalcium phosphate incorporated root dentin adhesive. SEM, EDX, FTIR, rheometric and bond strength study.

The aim was to formulate an experimental adhesive (EA) and added nanoparticles (NPs) of beta-tricalcium phosphate (ß-TCP) to see the impact on pushout bond strength (PBS) and other mechanical properties. Three adhesives were prepared, including EA (control, without ß-TCP NPs), 2.5%-ß-TCP NPs containing adhesive (2.5%-NPA), and 5% ß-TCP NPs containing adhesive (5%-NPA). For the characterization of the NPs, scanning electron microscopy (SEM) and energy dispersive X-ray (EDX) spectroscopy was accomplished. For the adhesive's characterization, rheological assessment, and degree of conversion (DC) analysis were performed. PBS of these adhesives against resin fiber post to root dentin, interfacial failure categories, and resin dentin interface analysis were also assessed. The ß-TCP NPs were seen as agglomerated asymmetrical particles on SEM. These NPs were composed primarily of calcium (Ca), and phosphorus (P). Rheological evaluation of the adhesive's showed a drop in the viscosity of all adhesives at greater angular frequencies. The greatest DC was detected for the EA group (67.54 ± 7.9) followed by 2.5%-NPA group (45.32 ± 5.1), whereas the lowest DC values were seen for the 5%-NPA group (38.97 ± 6.5). Concerning PBS, the 2.5%-NPA revealed the highest values at the coronal (12.81 ± 3.0) and middle (8.50 ± 2.3) sections, whereas, for the apical section, the highest PBS values were seen for the 5%-NPA (4.9 ± 1.6). Most of the failures for all adhesive groups were seen at the adhesive-dentin interface (cohesive type failures) for all root segments (coronal, middle, and apical). The resin-dentin interface analysis verified hybrid layer and resin tag formation for all adhesives, but the presence of dispersed ß-TCP NPs was only seen in the two NP-reinforced adhesives. The adding of ß-TCP NPs in the adhesive could be beneficial as it could improve its PBS. Suitable rheological properties and dentin interaction were also observed for NP-reinforced adhesives. A reduced DC was seen for both ß-TCP NP-containing adhesives as compared to the EA. RESEARCH HIGHLIGHTS: Experimental adhesives were reinforced with beta-tricalcium phosphate (ß-TCP) nanocrystals. The ß-TCP NPs were seen as agglomerated asymmetrical particles on SEM. These NPs were composed primarily of calcium (Ca), and phosphorus (P). ß-TCP adhesives demonstrated superior pushout bond strength and a drop in the adhesive viscosity at greater angular frequencies compared to control adhesive. The greatest DC was detected for the EA group followed by 2.5%- ß-TCP group, whereas the lowest DC values were for the 5%- ß-TCP group.

Influence of carbon and graphene oxide nanoparticle on the adhesive properties of dentin bonding polymer: A SEM, EDX, FTIR study.

OBJECTIVE: This study was aimed at including 2.5 wt.% of carbon nanoparticles (CNPs) and graphene oxide NPs (GNPs) in a control adhesive (CA) and then investigate the effect of this inclusion on their mechanical properties and its adhesion to root dentin. MATERIALS AND METHODS: Scanning electron microscopy and energy dispersive X-ray (SEM-EDX) mapping were conducted to investigate the structural features and elemental distribution of CNPs and GNPs, respectively. These NPs were further characterized by Raman spectroscopy. The adhesives were characterized by evaluating their push-out bond strength (PBS), rheological properties, degree of conversion (DC) investigation, and failure type analysis. RESULTS: The SEM micrographs revealed that the CNPs were irregular and hexagonal, whereas the GNPs were flake-shaped. EDX analysis showed that carbon (C), oxygen (O), and zirconia (Zr) were found in the CNPs, while the GNPs were composed of C and O. The Raman spectra for CNPs and GNPs revealed their characteristic bands (CNPs-D band: 1334 cm-1, GNPs-D band: 1341 cm-1, CNPs-G band: 1650 cm-1, and GNPs-G band: 1607 cm-1). The testing verified that the highest bond strength to root dentin were detected for GNP-reinforced adhesive (33.20 ± 3.55 MPa), trailed closely by CNP-reinforced adhesive (30.48 ± 3.10 MPa), while, the CA displayed lowest values (25.11 ± 3.60 MPa). The inter-group comparisons of the NP-reinforced adhesives with the CA revealed statistically significant results (p < 0.01). Failures of adhesive nature were most common in within the adhesives and root dentin. The rheological assessment results demonstrated a reduced viscosity for all the adhesives observed at advanced angular frequencies. All the adhesives verified suitable dentin interaction shown by hybrid layer and appropriate resin tag development. A reduced DC was perceived for both NP-reinforced adhesives, compared to the CA. CONCLUSION: The present study's findings have demonstrated that 2.5% GNP adhesive revealed the highest, suitable root dentin interaction, and acceptable rheological properties. Nevertheless, a reduced DC was observed (matched with the CA). Prospective studies probing the influence of diverse concentrations of filler NPs on the adhesive's mechanical properties to root dentin are recommended.

Global research on dental polymers and their application: A bibliometric analysis and knowledge mapping.

Purpose: The main objective of the current study was to evaluate the top-cited articles, countries, journals, authors, and papers published related to dental polymers and their application. Research articles published from 1962 to 2021 on dental polymers and their application were identified using the Scopus database. Methodology: Bibliographical data related to the abstract, citations, keywords, and other relevant information was extracted using different combinations of keywords. Further evaluation and visualization of the selected data were performed with the help of various tools, including MS Excel, Microsoft Word, Google open refine, Biblioshiny, BibExcel, and VOS viewer. An initial search revealed 351 documents, of which 327 were chosen for further analysis. Results: A substantial increase in the number of publications related to this domain was observed. The United States was the most prolific country, while the Aristotle University of Thessaloniki from Greece was identified as the leading institute. Conclusion: This bibliometric analysis can guide researchers, funding agencies, industry, and institutions.

Adhesive Bond Integrity of Experimental Zinc Oxide Nanoparticles Incorporated Dentin Adhesive: An SEM, EDX, µTBS, and Rheometric Analysis.

Objective: Our study is aimed at preparing an experimental adhesive (EA) and assessing the influence of adding 5-10 wt.% concentrations of zinc oxide (ZnO) nanoparticles on the adhesive's mechanical properties. Methods: Field emission scanning electron microscopy (FESEM) and energy dispersive X-ray (EDX) spectroscopy were employed to investigate the morphology and elemental distribution of the filler nanoparticles. To examine the adhesive properties, microtensile bond strength (µTBS) testing, an investigation of the rheological properties, degree of conversion (DC), and analysis of the interface between the adhesive and dentin were carried out. Results: The SEM micrographs of ZnO nanoparticles demonstrated spherical agglomerates. The EDX plotting confirmed the incidence of Zn and oxygen (O) in the ZnO nanoparticles. The highest µTBS was observed for nonthermocycled (NTC) 5 wt.% ZnO group (32.11 ± 3.60 MPa), followed by the NTC-10 wt.% ZnO group (30.04 ± 3.24 MPa). Most of the failures observed were adhesive in nature. A gradual reduction in the viscosity was observed at higher angular frequencies, and the addition of 5 and 10 wt.% ZnO to the composition of the EA lowered its viscosity. The 5 wt.% ZnO group demonstrated suitable dentin interaction by showing the formation of resin tags, while for the 10 wt.% ZnO group, compromised resin tag formation was detected. DC was significantly higher in the 0% ZnO (EA) group. Conclusion: The reinforcement of the EA with 5 and 10 wt.% concentrations of ZnO nanoparticles produced an improvement in the adhesive's µTBS. However, a reduced viscosity was observed for both nanoparticle-reinforced adhesives, and a negotiated dentin interaction was seen for 10 wt.% ZnO adhesive group. Further research exploring the influence of more filler concentrations on diverse adhesive properties is recommended.

Current Scientific Research Trends on Salivary Biomarkers: A Bibliometric Analysis.

Salivary biomarkers are indicators of many biological and pathological conditions and provide further information regarding the early detection of diseases. This bibliometric analysis aims to identify and evaluate the scientific literature addressing salivary biomarkers from a dental perspective, to identify the most prolific organizations, authors, journals, countries, and keywords used within this research domain. An electronic search was performed using Elsevier's Scopus database. From a total of 587 retrieved papers (published between 1997 and 2021), 399 were selected. For the data analysis and its visualization, the title of the articles, year of publication, countries, authors, journals, articles, and keywords were analyzed using Microsoft Excel and VOSviewer (a bibliometric software program). An increase in the number of publications was identified from 1997 to 2021. The United States (U.S.) published the most papers (84) and received the highest citations (3778), followed by India and Brazil. The Journal of Periodontology published the highest number of articles (39) that received the highest citations. The University of Kentucky from the U.S. published most of the papers related to salivary biomarkers that received the highest citations. Timo Sorsa published the most papers (14 papers), while Craig Miller was the highest cited author (754 citations). Concerning the highly cited papers, a paper by Micheal et al., published in 2010, received the highest citations (487 citations). "Saliva", followed by "human", were the most common keywords used by the authors in the papers related to salivary biomarkers. The findings of this analysis revealed an increase in salivary biomarker-related publications that positively influenced the number of citations each paper received. The U.S. produced the most publications that received the highest citations, and the University of Kentucky, U.S., was the most prominent. The articles were mostly published in the Journal of Periodontology and received the highest number of citations.

The Effect of Sealer Application Methods on Voids Volume after Aging of Three Calcium Silicate-Based Sealers: A Micro-Computed Tomography Study.

During obturation, air voids are undesirable as they may provide shelter for microorganisms or passage for fluids. This study aimed to compare the occurrence of voids between three calcium silicate-based sealers (CSBSs) (MTA-Fillapex, BioRoot-RCS, Bio-C) and the change in their volume after aging. In addition, we aimed to compare voids when using two sealer application methods: lentulo-spiral (LS) and gutta-percha (GP) cone. Thirty extracted mandibular premolars (n = 30) were endodontically prepared and obturated using single GP cone (SGPC) technique. Each sealer was applied to 10 teeth (n = 10) using LS or GP. Micro-computed tomography (micro-CT) was used to quantify the volume of root filling and voids before and after 8-week storage in a phosphate-rich medium. The percentage of root filling and voids were compared between the groups using a Mann-Whitney U test and Kruskal-Wallis test with a Bonferroni correction. Before aging, the percentages of root filling volume after obturation were comparable with no significant differences between sealers (p = 0.325) or application methods (p = 0.950). After aging, the voids' volume increased significantly in all sealers (p ≤ 0.05). However, no significant differences were found between sealers (p = 0.302). In conclusion, voids in CSBSs may not reduce in size with aging; hence, SGPC should be carefully selected for suitable cases.

An Assessment of Various Challenges Perceived by Dental Students amidst the COVID-19 Pandemic: A Digital Questionnaire Study.

The objective of our study was to evaluate dental students' perception of the challenges faced during the COVID-19 pandemic related to their clinical work, education, performance, online examinations, psychological health, and teamwork. A validated online questionnaire consisting of closed ended questions was sent to all the undergraduate dental students at our institute. Data were collected and analyzed statistically using a chi-square test to compare responses of male with female and junior with senior students. A total of 317 undergraduate dental students (N = 317) participated in this cross-sectional study. The most common challenges perceived by the participants were related to their exam duration (77.3%), patient availability (66.9%), difficulty in understanding online lectures (58.4%), and a fear of losing grades (57.4%). Participants reported that the COVID-19 pandemic affected their performance in the courses (75.4%), teamwork (72.2%), educational aspects (67.5%), and psychological health (51.1%). A significantly greater proportion of female students reported the adverse effects of COVID-19 on their psychological health than male students (p = 0.031). Senior students perceived the negative impact of COVID-19 on teamwork significantly more than the junior students (p = 0.004). The majority of students reported challenges during the COVID-19 pandemic. Female students and senior students perceived more challenges than their counterparts. Future studies from other institutes of this region are recommended to establish a clearer picture of COVID-19 related challenges faced by dental students.

Surface Properties of Polymer Resins Fabricated with Subtractive and Additive Manufacturing Techniques.

This study aimed to compare the surface roughness, hardness, and flexure strength of interim indirect resin restorations fabricated with CAD-CAM (CC), 3D printing (3D), and conventional techniques (CV). Twenty disk (3 mm × Ø10 mm) and ten bar specimens (25 × 2 × 2 mm) were fabricated for the CC, 3D, and CV groups, to be used for surface roughness, micro-hardness, and flexural strength testing using standardized protocol. Three indentations for Vickers micro-hardness (VHN) were performed on each disk and an average was identified for each specimen. Surface micro-roughness (Ra) was calculated in micrometers (µm) using a 3D optical non-contact surface microscope. A three-point bending test with a universal testing machine was utilized for assessing flexural strength. The load was applied at a crosshead speed of 3 mm/min over a distance of 25 mm until fracture. Means and standard deviations were compared using ANOVA and post hoc Tukey-Kramer tests, and a p-value of ≤0.05 was considered statistically significant. Ra was significantly different among the study groups (p < 0.05). Surface roughness among the CC and CV groups was statistically comparable (p > 0.05). However, 3D showed significantly higher Ra compared to CC and CV samples (p < 0.05). Micro-hardness was significantly higher in 3D samples (p < 0.05) compared to CC and CV specimens. In addition, CC and CV showed comparable micro-hardness (p > 0.05). A significant difference in flexural strength was observed among the study groups (p < 0.05). CC and 3D showed comparable strength outcomes (p > 0.05), although CV specimens showed significantly lower (p < 0.05) strength compared to CC and 3D samples. The 3D-printed provisional restorative resins showed flexural strength and micro-hardness comparable to CAD-CAM fabricated specimens, and surface micro-roughness for printed specimens was considerably higher compared to CAD-CAM and conventional fabrication techniques.

Psychological Impact of the COVID-19 Pandemic on Students, Assistants, and Faculty of a Dental Institute of Saudi Arabia.

This study aimed to assess the perceived stress levels in students, assistants, and faculty members of the College of Dentistry, Imam Abdulrahman Bin Faisal, University (IAU), Kingdom of Saudi Arabia (KSA) during the novel coronavirus disease 2019 (COVID-19) pandemic. Using the Cohen's perceived stress scale (PSS) questionnaire (consisting of 14 items, hence called PSS-14), an online observational survey was conducted. The PSS 14 was rated on a 5-point Likert scale ranging from 0 (never) to 4 (very often). The scores ranging from 0-18 represented low stress, 19-37 represented moderate stress, and 38-56 represented high stress. The second-and third-year students were designated as junior year students, while fourth-year onwards were considered senior year students. Out of total 265 participants, 65% (173) were female, and the majority of the participants were dental students 70% (185) with a mean age of 26.71 ± 9.26 years. In the present study, the average PSS score for the participants was computed as 29.89 (range score: 0-56) which shows moderate stress levels among the respondents. The PSS score for the students was 31.03; for the faculty, it was 28, while for the assistants, it was 27.05. Among the three participant groups, the students were found more on the severe stress side (19%) (p-value = 0.002), and among them, the senior year students (6th year) showed significantly higher stress levels compared to the junior year students (p-value = 0.005). Age-wise, the participants below 20 years were most stressed (21%), followed by those 20-30 years old (18%). Female participants were more severely stressed than males (17% vs. 10%, respectively). It was concluded that the students experienced more stress, followed by the faculty members and dental assistants. In addition, younger participants, females, and senior year students were more stressed than their counterparts. Future studies directed at evaluating stress levels of these groups from different dental institutes could provide an opportunity for policymakers to offer various resources to improve their mental health.

Enamel Remineralization Competence of a Novel Fluoride-Incorporated Bioactive Glass Toothpaste-A Surface Micro-Hardness, Profilometric, and Micro-Computed Tomographic Analysis.

This study aimed to analyze the enamel remineralization efficacy of a novel fluoridated bioactive glass (F-BG) toothpaste compared to a standard fluoride toothpaste. Seventy-two enamel blocks (N = 72) were divided into groups of twenty-four blocks according to the toothpaste exposure-group 1: brushed with distilled water, group 2: brushed with fluoride toothpaste (ColgateTM), and group 3: brushed with F-BG toothpaste (BioMinFTM). Pre-brushing, enamel blocks were demineralized using 6 wt.% citric acid (pH = 2.4). Tooth brushing was performed using a mixture of respective toothpaste and artificial saliva (AS), and each enamel block received 5000 linear strokes. The samples were assessed for surface micro-hardness (to estimate Vickers hardness number, VHN), surface roughness (Ra), and volume loss/gain using micro-computed tomography (micro-CT). The highest increase in the VHN was noticed for group 3 (117.81) followed by group 2 (61.13), and all the intragroup comparisons were statistically significant (p < 0.05). Demineralization increased the Ra values, and a decrease was observed post-remineralization for all the groups. The maximum Ra decrease was observed for group 3 (-223.2 nm) followed by group 2 (-55.6 nm), and all the intragroup comparisons were again statistically significant (p < 0.05). Micro-CT investigation revealed that the enamel volume decreased after demineralization and increased after remineralization among all groups. The F-BG toothpaste showed greater enamel surface micro-hardness (increased VHN), smoother surface (low roughness), and better volume restoration (remineralization) in comparison to the fluoride toothpaste.

Influence of TiO2 and ZrO2 Nanoparticles on Adhesive Bond Strength and Viscosity of Dentin Polymer: A Physical and Chemical Evaluation.

The present study aimed to formulate an experimental adhesive (EA) and reinforce it with 5 wt.% titanium dioxide (TiO2) or zirconium oxide (ZrO2) to yield 5% TiO2 and 5% ZrO2 adhesives, respectively, and then analyze the impact of this reinforcement on various mechanical properties of the adhesives. The EA contained a blend of monomers such as bisphenol A glycol dimethacrylate (BisGMA), triethylene glycol dimethacrylate (TEGDMA), 2-hydroxyethyl methacrylate (HEMA), and ethyl 4-dimethylamino benzoate and camphorquinone. The EA included ethyl 4-dimethylamino benzoate and camphorquinone photo-initiators, and diphenyliodonium hexafluorophosphate (DPIHP) was also included to act as an electron initiator. The TiO2 and ZrO2 nanoparticles were incorporated into the EA post-synthesis. To characterize the filler nanoparticles, scanning electron microscopy (SEM) and line-energy dispersive X-ray (EDX) spectroscopy were performed. The adhesives were characterized by analyzing their rheological properties, shear-bond strength (SBS), and interfacial failure types. Further, the resin-dentin interface was also analyzed via SEM. The TiO2 nanoparticles were spherically shaped on the SEM micrographs, while the ZrO2 nanoparticles were seen as non-uniformly shaped agglomerates. The EDX mapping demonstrated the presence of Ti and oxygen for TiO2 and Zr and oxygen for the ZrO2 nanoparticles. Both 5% TiO2 and 5% ZrO2 adhesives revealed decreased viscosity as compared with the EA. The 5% TiO2 adhesive demonstrated higher SBS values for both non-thermocycled (NTC) and thermocycled samples (NTC: 25.35 ± 1.53, TC: 23.89 ± 1.95 MPa), followed by the 5% ZrO2 adhesive group (NTC: 23.10 ± 2.22, TC: 20.72 ± 1.32 MPa). The bulk of the failures (>70%) were of adhesive type in all groups. The SEM analysis of the resin-dentin interface revealed the development of a hybrid layer and resin tags (of variable depth) for the EA and 5% TiO2 groups. However, for the 5% ZrO2 group, the hybrid layer and resin tag establishment appeared compromised. Reinforcement of the EA with TiO2 or ZrO2 caused an increase in the adhesive's SBS (with the 5% TiO2 group demonstrating the highest values) in comparison with the EA (without nanoparticles). However, both nanoparticle-containing adhesives revealed decreased viscosity compared with the EA (without nanoparticles). Further studies investigating the impact of diverse filler concentrations on the properties of adhesives are suggested.

Application of ß-Tricalcium Phosphate in Adhesive Dentin Bonding.

The study aimed at synthesizing ß-tricalcium phosphate (ß-TCP) nanoparticles and comparing the mechanical properties and dentin interaction of two adhesives: experimental adhesive (EA) and EA with 5 wt.% ß-TCP nanoparticles (ß-TCP-5%). These filler nanoparticles were synthesized and then characterized with scanning electron microscopy (SEM) and micro-Raman spectroscopy. The ß-TCP nanoparticles were incorporated in the adhesives to form two groups: gp-1: EA (control) and gp-2: ß-TCP-5%. These adhesives were characterized by SEM, energy-dispersive X-ray (EDX) spectroscopy and were also assessed for their micro-tensile bond strength (µTBS) with (TC) and without thermocycling (NTC). Fourier Transform Infrared (FTIR) spectroscopy was performed to evaluate the degree of conversion (DC) of two adhesives. The ß-TCP filler was seen as irregularly shaped agglomerates on SEM. The micro-Raman spectra revealed characteristic peaks associated with ß-TCP nanoparticles. Both adhesives presented suitable dentin interaction, which was demonstrated by the formation of resin tags of variable depths. The EDX analysis verified the existence of calcium (Ca) and phosphate (P) for the ß-TCP-5% group. The greatest µTBS values were shown by ß-TCP-5% group samples when they were non-thermocycled (NTC) (ß-TCP-5%-NTC: 34.11 ± 3.46) followed by the thermocycled (TC) samples of the same group (ß-TCP-5%-TC: 30.38 ± 3.66), compared with the EA group. Although the DC presented by ß-TCP-5% group was comparable to the EA group, it was still lower. The addition of ß-TCP nanoparticles in the adhesive improved its µTBS and resulted in a suitable dentin interaction, seen in the form of hybrid layer and resin tag formation. Nonetheless, a decreased DC was observed for the ß-TCP-5% adhesive. Future studies probing the effect of different filler concentrations on various properties of the adhesive are warranted.

Assessment of Bond Integrity, Durability, and Degree of Conversion of a Calcium Fluoride Reinforced Dentin Adhesive.

Our study aimed to synthesize and compare the mechanical properties and dentin interaction of two adhesives; experimental adhesive (EA) and EA containing 5 wt.% calcium fluoride (CaF2) nano-crystals (CaF2 adhesive-CAFA). CaF2 nano-crystals were synthesized by reacting two solutions (containing calcium and fluoride) in a glass chamber using a heated air system. The EA was produced using a mix of monomers, photo-initiators, camphorquinone, and electron initiators. The synthesized CaF2 nano-crystals were centrifuged to guarantee that inside the adhesive there is homogenized dispersion of the filler particles. Their integration in the EA yielded two groups; Gp-1: EA (without CaF2, control) and Gp-2: (5 wt.% CaF2 containing adhesive, CAFA). Sixty teeth were prepared and set to form bonded specimens using the two adhesives. The CaF2 nano-crystals were irregularly shaped with an average particle size of 30-200 nm. The highest µTBS values were obtained for CAFA-non-thermocycled (NTC) samples (32.63 ± 3.15), followed by EA-NTC (31.80 ± 3.75) specimens. On thermocycling (TC), both adhesive groups presented lower µTBS values (CAFA-TC: 29.47 ± 3.33 and EA-TC: 24.04 ± 3.69). Hybrid layer (HL) formation and resin tags of varying depths were perceived for both adhesive groups. The EDX analysis demonstrated the presence of carbon (C), silica (Si), calcium (Ca), and fluoride (F) for CAFA group. Micro-Raman spectroscopy revealed distinct peaks for CaF2 nano-crystals. The CAFA group presented the greatest DC. The addition of CaF2 nano-crystals in the adhesive caused improved bond µTBS and DC. The incorporation also demonstrated suitable dentin interaction, depicted by appropriate HL and resin tag development.

Synergistic Effect of Bioactive Inorganic Fillers in Enhancing Properties of Dentin Adhesives-A Review.

Dentin adhesives (DAs) play a critical role in the clinical success of dental resin composite (DRC) restorations. A strong bond between the adhesive and dentin improves the longevity of the restoration, but it is strongly dependent on the various properties of DAs. The current review was aimed at summarizing the information present in the literature regarding the improvement of the properties of DAs noticed after the addition of bioactive inorganic fillers. From our search, we were able to find evidence of multiple bioactive inorganic fillers (bioactive glass, hydroxyapatite, amorphous calcium phosphate, graphene oxide, calcium chloride, zinc chloride, silica, and niobium pentoxide) in the literature that have been used to improve the different properties of DAs. These improvements can be seen in the form of improved hardness, higher modulus of elasticity, enhanced bond, flexural, and ultimate tensile strength, improved fracture toughness, reduced nanoleakage, remineralization of the adhesive-dentin interface, improved resin tag formation, greater radiopacity, antibacterial effect, and improved DC (observed for some fillers). Most of the studies dealing with the subject area are in vitro. Future in situ and in vivo studies are recommended to positively attest to the results of laboratory findings.

Influence of ER-CR-YSGG Laser and Photodynamic Therapy on the Dentin Bond Integrity of Nano-Hydroxyapatite Containing Resin Dentin Adhesive: SEM-EDX, Micro-Raman, Micro-Tensile, and FTIR Evaluation.

The study aimed to analyze the effect of the addition of nano-hydroxyapatite (nano-HA) particles on the mechanical properties of experimental adhesive (EA). Furthermore, dentin interaction of EA (without nano-HA) and EA with nano-HA (hereon referred to as HA-10%) were also investigated and equated. Methods consisting of scanning electron microscopy (SEM)-energy-dispersive X-ray spectroscopy (EDX), micro-Raman spectroscopy, micro-tensile bond strength (µTBS) test, and Fourier transform infrared (FTIR) spectroscopy were employed to study nano-HA particles shape, dentin bond strength, degree of conversion (DC), and adhesive-dentin interaction. Ninety teeth (N = 90) were collected, and pre-bonding, conditioning of dentin was performed utilizing phosphoric acid (H3PO4) etching, photodynamic therapy (PDT), and ER-CR-YSGG (ECY) laser. The teeth were set to form bonded specimens using two adhesives. Nano-HA particles were spherical-shaped, and EDX confirmed the presence of oxygen, calcium, and phosphorus. Micro-Raman spectroscopy revealed distinct phosphate and carbonate peaks for nano-HA. The µTBS test demonstrated highest values for HA-10% group on the H3PO4 conditioned dentin. The greatest DC was observed for the EA group. The addition of nano-HA-10 wt.% particles in dentin adhesive resulted in improved bond strength. The incorporation also demonstrated acceptable DC (although lower than EA group), suitable dentin interaction, and resin tag formation.

Influence of Different Conditioning Treatments on the Bond Integrity of Root Dentin to rGO Infiltrated Dentin Adhesive. SEM, EDX, FTIR and MicroRaman Study.

The present study aimed to synthesize and equate the mechanical properties and dentin interaction of two adhesives; experimental adhesive (EA) and 5 wt.% reduced graphene oxide rGO) containing adhesive. Scanning electron microscopy (SEM)-Energy-dispersive X-ray spectroscopy (EDX), Micro-Raman spectroscopy, push-out bond strength test, and Fourier Transform Infrared (FTIR) spectroscopy were employed to study nano-bond strength, degree of conversion (DC), and adhesive-dentin interaction. The EA was prepared, and rGO particles were added to produce two adhesive groups, EA-rGO-0% (control) and rGO-5%. The canals of sixty roots were shaped and prepared, and fiber posts were cemented. The specimens were further alienated into groups based on the root canal disinfection technique, including 2.5% sodium hypochlorite (NaOCl), Photodynamic therapy (PDT), and ER-CR-YSGG laser (ECYL). The rGO nanoparticles were flake-shaped, and EDX confirmed the presence of carbon (C). Micro-Raman spectroscopy revealed distinct peaks for graphene. Push-out bond strength test demonstrated highest values for the EA-rGO-0% group after NaOCl and PDT conditioning whereas, rGO-5% showed higher values after ECYL conditioning. EA-rGO-0% presented greater DC than rGO-5% adhesive. The rGO-5% adhesive demonstrated comparable push-out bond strength and rheological properties to the controls. The rGO-5% demonstrated acceptable DC (although lower than control group), appropriate dentin interaction, and resin tag establishment.

Optical coherence tomography's current clinical medical and dental applications: a review.

Optical coherence tomography (OCT) is a non-invasive investigative technique that is used to obtain high-resolution three-dimensional (3D) images of biological structures. This method is useful in diagnosing diseases of specific organs like the eye, where a direct biopsy cannot be conducted. Since its inception, significant advancements have been made in its technology. Apart from its initial application in ophthalmology for retinal imaging, substantial technological innovations in OCT brought by the research community have enabled its utilization beyond its original scope and allowed its application in many new clinical areas. This review presents a summary of the clinical applications of OCT in the field of medicine (ophthalmology, cardiology, otology, and dermatology) and dentistry (tissue imaging, detection of caries, analysis of dental polymer composite restorations, imaging of root canals, and diagnosis of oral cancer). In addition, potential advantages and disadvantages of OCT are also discussed.

The Impact of Tick-Borne Diseases on the Bone.

Tick-borne infectious diseases can affect many tissues and organs including bone, one of the most multifunctional structures in the human body. There is a scarcity of data regarding the impact of tick-borne pathogens on bone. The aim of this review was to survey existing research literature on this topic. The search was performed using PubMed and Google Scholar search engines. From our search, we were able to find evidence of eight tick-borne diseases (Anaplasmosis, Ehrlichiosis, Babesiosis, Lyme disease, Bourbon virus disease, Colorado tick fever disease, Tick-borne encephalitis, and Crimean-Congo hemorrhagic fever) affecting the bone. Pathological bone effects most commonly associated with tick-borne infections were disruption of bone marrow function and bone loss. Most research to date on the effects of tick-borne pathogen infections on bone has been quite preliminary. Further investigation of this topic is warranted.

Dentin Bond Integrity of Filled and Unfilled Resin Adhesive Enhanced with Silica Nanoparticles-An SEM, EDX, Micro-Raman, FTIR and Micro-Tensile Bond Strength Study.

The objective of this study was to synthesize and assess unfilled and filled (silica nanoparticles) dentin adhesive polymer. Methods encompassing scanning electron microscopy (SEM)-namely, energy dispersive X-ray spectroscopy (EDX), micro-tensile bond strength (µTBS) test, Fourier transform infrared (FTIR), and micro-Raman spectroscopy-were utilized to investigate Si particles' shape and incorporation, dentin bond toughness, degree of conversion (DC), and adhesive-dentin interaction. The Si particles were incorporated in the experimental adhesive (EA) at 0, 5, 10, and 15 wt. % to yield Si-EA-0% (negative control group), Si-EA-5%, Si-EA-10%, and Si-EA-15% groups, respectively. Teeth were set to form bonded samples using adhesives in four groups for µTBS testing, with and without aging. Si particles were spherical shaped and resin tags having standard penetrations were detected on SEM micrographs. The EDX analysis confirmed the occurrence of Si in the adhesive groups (maximum in the Si-EA-15% group). Micro-Raman spectroscopy revealed the presence of characteristic peaks at 638, 802, and 1300 cm-1 for the Si particles. The µTBS test revealed the highest mean values for Si-EA-15% followed by Si-EA-10%. The greatest DC was appreciated for the control group trailed by the Si-EA-5% group. The addition of Si particles of 15 and 10 wt. % in dentin adhesive showed improved bond strength. The addition of 15 wt. % resulted in a bond strength that was superior to all other groups. The Si-EA-15% group demonstrated acceptable DC, suitable dentin interaction, and resin tag formation.

Efficacy of propolis in remineralising artificially induced demineralisation of human enamel - An in-vitro study.

OBJECTIVE: In this in vitro study, we aimed to analyse the enamel-remineralisation potential of propolis. MATERIALS AND METHODS: Twenty enamel blocks (N = 20) were randomly divided into two groups (n = 10). In group 1 (control), enamel blocks were brushed with artificial saliva (AS). In group 2, they were brushed with propolis oil. All the blocks were demineralised by exposing them to 6 wt% citric acid (pH: 2.2) for 5 min. Brushing was performed inside a tooth brushing simulation machine with manual toothbrushes. Each sample received 5,000 linear strokes. Surface microhardness analysis was performed for each sample at three time intervals (pre-demineralisation or baseline, post-demineralisation, and post-remineralisation) to obtain the Vickers hardness numbers (VHNs). RESULTS: An enhancement in the microhardness of the enamel samples was observed after brushing with propolis oil when compared with brushing using AS alone. In group 1 (control group), the mean baseline VHN was 583.66. It decreased to 116.23 after demineralisation and increased to 184.02 after remineralisation. The mean baseline VHN of group 2 was 506.91. It decreased to 317.60 after demineralisation and increased to 435.19 after remineralisation. The VHN values of both the groups revealed statistically significant differences (p < 0.05) in inter-group and intra-group comparisons. CONCLUSION: Brushing of enamel blocks with propolis led to a greater enhancement in their microhardness levels when compared with the control group. Future studies are essential to validate the exact mechanism of the beneficial effects of propolis on enamel.