Using Functionalized Micron-Sized Glass Fibres for the Synergistic Effect of Glass Ionomer on Luting Material.

This laboratory experiment was conducted with the objective of augmenting the mechanical properties of glass ionomer cement (GIC) via altering the composition of GIC luting powder through the introduction of micron-sized silanized glass fibres (GFs). Experimental GICs were prepared through the addition of two concentrations of GFs (0.5% and 1.0% by weight) to the powder of commercially available GIC luting materials. The effect of GF in set GIC was internally evaluated using micro-CT while the mechanical attributes such as nano hardness (nH), elastic modulus (EM), compressive strength (CS), and diametral tensile strength (DTS) were gauged. Additionally, the physical properties such as water solubility and sorption, contact angle (CA), and film thickness were evaluated. Reinforced Ketac Cem Radiopaque (KCR) GIC with 0.5 wt.% GF achieved improved nH, EM, CS, and DTS without affecting the film thickness, CA or internal porosity of the set GIC cement. In contrast, both GF-GIC formulations of Medicem (MC) GIC showed the detrimental effect of the GF incorporation. Reinforcing KCR GIC with 0.5 wt.% silanized GFs could improve the physical and mechanical attributes of luting material. Silanized GF, with optimal concentration within the GIC powder, can be used as a functional additive in KCR GIC with promising results.

Minocycline incorporated cobalt oxide nanoparticles in dental sealants: An in vitro study.

The purpose of this study was to introduce antibacterial property to pits and fissure sealant (PFS) in order to mitigate the major clinical problems associated with PFS, such as microleakage and secondary caries. We prepared a pH reliant cobalt oxide nanoparticle incorporated with minocycline (MNC@CO) and characterized to investigate its antibacterial potential against Streptococcus sobrinus. The physiochemical, morphological, and drug release kinetics at different pH (7.4, 5.0, and 3.5) from nanoparticles were investigated. The MNC@CO were added at 2.5% and 5.0% into experimental PFS and characterized for their antibiofilm capacity, biocompatibility, and mechanical properties including compressive and flexural strength. The groups 2.5% and 5.0% has shown statistically significant antimicrobial capacity against S. sobrinus compared to control (p < .05). The highest percentage of MNC release at different pH (especially at pH 5.0 and 3.5) was observed from 5.0% MNC@CO doped PFS. The PFS doped with 2.5% MNC@CO showed a highest compressive strength (110 MPa) over a period of 70 days as compared to 5.0% MNC@CO (75 MPa) and control (80 MPa). The flexural strength of both experimental groups was lower for both time points (24 h and 30 days) than control. In conclusion, the present study found that 2.5% MNC@CO doped PFS showed considerable anti-biofilm potential without compromising mechanical properties.

Dental restoration selection by students at southern Saudi Arabian universities.

Dental caries is a serious oral health concern and restoration of teeth is the main solution to this issue. Various restorative materials having different properties are used for posterior restoration. The aim of this study was to find that which factors can affect the choice of selection of material for posterior restoration among dental graduate students. For this purpose, a questionnaire was shared electronically among students of three different universities (King Khalid University, Jazan University, and Najran University). After collection, data were subjected to a chi-square test to check the significance. It has been observed that almost 50% of participants choose composite resin for posterior restoration. Results showed that according to most (more than 50%) of the dental students in Southern Saudi Arabia, different patient and tooth condition related factors can affect the choice for selection of restorative material.

A method of locating the abutment screw access channel with cone-beam computed tomography and a 3D-printed drilling guide.

In managing loose abutment screws, locating precisely the position of the screw access channel is difficult. This technique describes the use of cone-beam computed tomography (CBCT) and surgical guide planning software to locate the screw access channel with the intention of retrieving a loosened cement-retained implant-supported prosthesis. The method minimizes damage to the abutment crown assembly.

Effect of anatomic, semi-anatomic and non-anatomic occlusal surface tooth preparations on the adaptation of zirconia copings.

PURPOSE: To compare the accuracy of marginal and internal adaptation of zirconia (Zr) copings fabricated on anatomic (A), semi-anatomic (SA) and non-anatomic (NA) occlusal surface preparations. MATERIALS AND METHODS: 45 extracted bicuspid teeth were prepared for receiving zirconia crowns, with different occlusal preparation designs A=15, SA=15 & NA=15. The Zr copings were fabricated by using CAD4DENT, CAD/CAM. The copings were adjusted, cemented and were cross sectioned centrally from buccal cusp tip to lingual cusp tip into mesial and distal halves. The copings were examined under electron microscope at ×200 magnification and the measurements were recorded at 9 predetermined areas in micrometers. RESULTS: Overall mean gap values for the three groups was found to be 155.93±33.98 µm with Anatomical Occlusal preparation design having the least gap value of 139.23±30.85 µm showing the best adaptation among the groups. Post Hoc Tukey's test showed a statistically significant difference (P=.007) between the means of gap for A & NA preparation designs. Measurements recorded at 9 predetermined points showed variations for the three groups. CONCLUSION: Anatomical occlusal preparation designs resulted in better marginal and internal adaptation of Zr copings. There is a considerable variation between the measured marginal and internal gap values for the Zr copings fabricated by the (CAD4DENT-CAD/CAM). This variation may be associated with the lack of standardization of the preparation of teeth, computerized designing of the coping for each tooth, cement used, uniform pressure application during the cementation of the copings, sectioning of the copings and the microscopic measurements.