Examining the Effects of Asiaticoside on Dental Pulp Stem Cell Viability and Proliferation: A Promising Approach to Root Canal Treatment.

AIM: This study aims to evaluate the impact of asiaticoside (AC) on the viability and proliferation of dental pulp stem cells (DPSCs), considering the known negative effects of routinely used intracanal medicaments. This evaluation will be compared with the outcomes from using traditional intracanal medicaments, specifically triple antibiotic paste (TAP) and calcium hydroxide [Ca(OH)2]. MATERIALS AND METHODS: The DPSCs were obtained from the third molars of an adult donor. The application of flow cytometry was employed to do a phenotypic analysis on DPSCs using CD90, CD73, CD105, CD34, CD14, and CD45 antibodies. The methylthiazol tetrazolium (MTT) assay was employed to assess cellular viability. The cells were treated with different concentrations of TAP and Ca(OH)2 (5, 2.5, 1, 0.5, and 0.25 mg/mL), along with AC (100, 50, 25, 12.5, and 6.25 µM). A cell proliferation rate was performed at 3, 5, and 7 days. RESULTS: The characterization of DPSCs was conducted by flow cytometry analysis, which verified the presence of mesenchymal cell surface antigen molecules (CD105, CD73, and CD90) and demonstrated the absence of hematopoietic markers (CD34, CD45, and CD14). Cells treated with concentrations over 0.5 mg/mL of TAP and Ca(OH)2 showed a notable reduction in cell viability in comparison to the untreated cells (p < 0.05). Additionally, the cells treated with different concentrations of AC 12.5, 6.25, 25, and 50 µM did not differ significantly from the untreated cells (p > 0.05). Nevertheless, cells treated with concentrations of 100 µM showed a significant reduction in viability compared to the untreated cells (p < 0.05). After a period of 7 days, it was noted that cells exposed to three different concentrations of AC (50, 25, and 12.5 µM) had a notable rise in cell density in comparison to TAP and Ca(OH)2 (p < 0.05). Furthermore, cells that were exposed to a concentration of 12.5 µM exhibited the highest cell density. CONCLUSION: The cellular viability of the AC-treated cells was superior to that of the TAP and Ca(OH)2-treated cells. Moreover, the AC with a concentration of 12.5 µM had the highest degree of proliferation. CLINICAL SIGNIFICANCE: This study underscores the importance of evaluating alternative root canal medicaments and their effects on DPSCs' growth and vitality. The findings on AC, particularly its influence on the survival and proliferation of DPSCs, offer valuable insights for its probable use as an intracanal medication. This research contributes to the ongoing efforts to identify safer and more effective intracanal treatments, which are crucial for enhancing patient outcomes in endodontic procedures. How to cite this article: Alazemi MJ, Badawi MF, Elbeltagy MG, et al. Examining the Effects of Asiaticoside on Dental Pulp Stem Cell Viability and Proliferation: A Promising Approach to Root Canal Treatment. J Contemp Dent Pract 2024;25(2):118-127.

A novel intra-tumoral drug delivery carrier for treatment of oral squamous cell carcinoma.

The treatment of oral squamous cell carcinoma (OSCC) includes systemic chemotherapy and is associated with aggressive side effects on patients. This study evaluated a new intra-tumor-targeted drug delivery method for the treatment of OSCC induced on the dorsum of the tongue in white mice. The induced tumors were examined by needle biopsy. A targeted anticancer drug (Cetuximab) and [Cisplatin and 5 Fluorouracil (5-FU)] chemotherapeutic agents were loaded on polyethylene glycol-polylactide-polyethylene glycol (PEG-PLA-PEG) nanoparticles (NPs) designed for intralesional injection while systemic administration was used as control. Fourier transform infrared spectroscopy (FTIR) was performed to study NP chemical structure, a drug release profile was conducted to study release kinetics, and histopathological evaluation was performed before and after treatment to evaluate tissue reactions (n-28, ά = 0.05). The drug release profile was characteristic of the chemotherapeutic agent showing early quick ascend followed by sustained slow release. FTIR peaks identified the polymeric structure of the drug nano-carrier. Histopathologic examination of chemically induced OSCC revealed different grades ranging from non-invasive to invasive stages of OSCC. Intra-tumoral test group revealed significant remission of observed cancer grade compared to the systemically administered group (X2 = 12.63, P < 0.001). Finally, using synthesized PEG-PLA-PEG NPs for intralesional injection is a promising route for the treatment of OSCC.

Study of the effect of different surface treatments and surface roughness of veneered crowns on shear bond strength of ceramic brackets.

The orthodontist is often faced with the problem of bonding brackets to ceramic restorations. The purpose of this study was to find the most reliable method for bonding ceramic brackets onto ceramic crowns.

Microtensile bond strength of etch and rinse versus self-etch adhesive systems.

The aim of this study was to compare the microtensile bond strength of the etch and rinse adhesive versus one-component or two-component self-etch adhesives. Twelve intact human molar teeth were cleaned and the occlusal enamel of the teeth was removed. The exposed dentin surfaces were polished and rinsed, and the adhesives were applied. A microhybride composite resin was applied to form specimens of 4 mm height and 6 mm diameter. The specimens were sectioned perpendicular to the adhesive interface to produce dentin-resin composite sticks, with an adhesive area of approximately 1.4 mm(2). The sticks were subjected to tensile loading until failure occurred. The debonded areas were examined with a scanning electron microscope to determine the site of failure. The results showed that the microtensile bond strength of the etch and rinse adhesive was higher than that of one-component or two-component self-etch adhesives. The scanning electron microscope examination of the dentin surfaces revealed adhesive and mixed modes of failure. The adhesive mode of failure occurred at the adhesive/dentin interface, while the mixed mode of failure occurred partially in the composite and partially at the adhesive/dentin interface. It was concluded that the etch and rinse adhesive had higher microtensile bond strength when compared to that of the self-etch adhesives.

Effect of surface conditioning and taper angle on the retention of IPS e.max Press crowns.

PURPOSE: The objective of this study was to evaluate the retentive strength of single-unit crowns with 10 degrees and 26 degrees taper angles cemented using two surface conditioning methods. MATERIALS AND METHODS: Thirty-two freshly extracted sound human molars were divided into two groups (n = 16) and prepared in a standardized manner with 10 degrees and 26 degrees taper angles. All-ceramic (IPS e.max Press) single crowns were fabricated for the prepared teeth. The crowns were then subdivided into two groups (n = 8), according to type of surface conditioning for the intaglio surfaces. Half the groups were HF acid etched and silanized, and the other half were conditioned with tribochemical silica coating and silanization. The crowns were cemented using adhesive cement (Panavia F 2.0). Retentive strength was measured in a universal testing machine. RESULTS: No significant difference was found between the mean retention forces for both 10 degrees and 26 degrees taper angles when the crowns were conditioned either with silica coating (613 +/- 190 N and 525 +/- 90 N, respectively), or with hydrofluoric (HF) acid etching and silanization (550 +/- 110 N and 490 +/- 130 N for 10 degrees and 26 degrees, respectively) (p= 0.32). CONCLUSION: Neither the surface conditioning type, nor the taper angle affected the retentive strength of IPS e.max Press single-unit crowns when cemented adhesively. Since silica coating and silanization did not show significant differences from HF acid gel and silanization, the former can be preferred for conditioning intaglio surfaces of glass ceramic crowns to avoid the use of the hazardous compound HF acid gel chairside.

Effect of reinforcement of high-impact acrylic resin with zirconia on some physical and mechanical properties / Efeito do reforço de resinas acrílicas de alto impacto com zircônia em algumas propriedades físicas e mecânicas

OBJECTIVES: To evaluate the effect of reinforcing high-impact acrylic resin (Metrocryl HI)with zirconia powder in two different concentrations on the transverse strength, impact strength,surface hardness, water sorption and solubility. MATERIALS AND METHODS: Fifteenspecimens were prepared for each test, five from Metrocryl HI resin as control, five others wereprepared from the 5% zirconia-modified Metrocryl HI resin, and another five specimens wereprepared from the 15% zirconia-modified Metrocryl HI resin. Transverse strength was assessedwith a 3-point bending test using a screw-driven testing machine. For the impact strength, a Charpytester was used. Surface hardness testing was conducted using Vickers tester. The water sorptionand solubility test was performed according to International Standards Organization specificationNo. 1567 for denture base polymers. Micro-structural examination of two specimens, onerepresenting each ZrO2 concentration group, was carried out using scanning electron microscopy.RESULTS: As determined by ANOVA and Bonferroni multiple comparison tests, the additionof zirconia resulted in a highly significant increase in transverse strength of high-impact acrylicresin (P< 0.001). This increase was proportional to the concentration of zirconia. No significantdifference was detected in each of impact strength, surface hardness and water solubility (P>0.05). Although a significant increase in water sorption was demonstrated (P< 0.05), still its meanvalue lies within the specification limits. CONCLUSIONS: Reinforcement of high-impact acrylicresin with zirconia powder increases its transverse strength significantly.

OBJETIVOS: Avaliar o efeito do reforço de resina acrílica de alto impacto (Metrocryl HI) compó de zircônia em duas diferentes concentrações, a forças transversais, de impacto, dureza desuperfície, absorção de água e solubilidade. MATERIAIS E MÉTODOS: 15 espécimes forampreparados para cada teste, sendo cinco com resina Metrocryl HI como controle, cinco preparadoscom resina modificada em 5% e cinco preparados com resina modificada em 15%. As forçastransversas foram determinadas com um teste de dobramento por máquina de parafuso. Para asforças de impacto, um testgador Charpy foi usado. A dureza de superfície foi verificada comteste de Vickers. A absorção de água foi testada de acordo com especificações n.o 1 567 daOrganização Internacional de Standards para polímeros de bases de dentaduras. O examemicroestrutural dos dois espécimes, um representando cada grupo de concentração de ZrO2, foiefetuado usando microscopia eletrônica. RESULTADOS: Testes ANOVA e Bonferroni decomparação múltipla demonstraram que houve um aumento significante na resistência transversaldas resinas de alto impacto (P<0.05). Este aumento foi proporcional na concentração de zircônia.Não houve diferenças significativas na resistência ao impacto, na dureza superficial e nasolubilidade na água (P>0.05), permanecendo dentro dos limites das especificações.CONCLUSÕES: O reforço de resinas de alto impacto com zircônia em pó aumentasignificativamente a resistência transversal.