The light-curing nanofilled glass ionomer (Ketac N100) showed the least microleakage.

Nanofibrillated cellulose, obtained from rice straw agricultural wastes was used as a substrate for the preparation of a new injectable and mineralized hydrogel for bone regeneration. Tetramethyl pyridine oxyl (TEMPO) oxidized nanofibrillated cellulose, was mineralized through the incorporation of a prepared and characterized biphasic calcium phosphate at a fixed ratio of 50 wt%. The TEMPO-oxidized rice straw nanofibrillated cellulose was characterized using transmission electron microscopy, Fourier transform infrared, and carboxylic content determination. The injectability and viscosity of the prepared hydrogel were evaluated using universal testing machine and rheometer testing, respectively. Cytotoxicity and alkaline phosphatase level tests on osteoblast like-cells for in vitro assessment of the biocompatibility were investigated. Results revealed that the isolated rice straw nanofibrillated cellulose is a nanocomposite of the cellulose nanofibers and silica nanoparticles. Rheological properties of the tested materials are suitable for use as injectable material and of nontoxic effect on osteoblast-like cells, as revealed by the positive alkaline phosphate assay. However, nanofibrillated cellulose/ biphasic calcium phosphate hydrogel showed higher cytotoxicity and lower bioactivity test results when compared to that of nanofibrillated cellulose.

BACKGROUND:The composition of the root canal filling materials together with the apical limit of the root canal obturation affect the complete periapical healing after root canal therapy.AIM:This study was performed to evaluate and compare the periapical healing in response to calcium-silicate (iRoot SP) and calcium-hydroxide (Apexit) based-sealers.MATERIAL AND METHODS:Seventy-two upper premolars root canals of six dogs were used. The teeth were randomly assigned to four groups: Group one: roots were obturated using gutta-percha and Apexit-sealer; Group two: roots were obturated using gutta-percha&iRoot SP-sealer; Group three: the teeth were left open without obturation; Group four: where healthy teeth were used as a negative control. Teeth were evaluated after one, two and three months. The newly formed mineralised apical tissue and the periapical inflammatory infiltrate of the obtained photomicrographs were evaluated, and scorings were statistically-analysed.RESULTS:The mean percentage of the periapical inflammatory infiltrates and mineralisation scoring after one, two and three months evaluation period were not significantly different among the four groups (P > 0.05).CONCLUSIONS:Regardless of the sealer used, iRoot SP and Apexit promote healing of periapical tissues. IRoot SP sealer showed early insignificant more partial and almost full healing after two and three months.

Nonsurgical local treatment of a periapical lesion arising from trauma or bacterial infection is a promising innovative approach. The present study investigated the feasibility of developing injectable amorphous calcium phosphate nanoparticles (ACP NPs) and ACP NPs loaded with an anti-inflammatory drug; ibuprofen (IBU-ACP NPs) in the form of thermoreversible in situ gels to treat periapical lesions with the stimulation of bone formation. NPs were produced by a spray-drying technique. Different formulations of Poloxamer 407 were incorporated with/without the produced NPs to form injectable gels. A drug release study was carried out. A 3 month in vivo test on a dog model also was assessed. Results showed successful incorporation of the drug into the NPs of CP during spray drying. The particles had mean diameters varying from 100 to 200 nm with a narrow distribution. A drug release study demonstrated controlled IBU release from IBU-ACP NPs at a pH of 7.4 over 24 h. The gelation temperature of the injectable in situ gels based on Poloxamer 407 was measured to be 30 °C. After 3 months of implantation in dogs, the results clearly demonstrated that the inclusion of ACP NPs loaded with IBU showed high degrees of periapical bone healing and cementum layer deposition around the apical root tip.

No abstract

The objective of this work is to prepare and verify the antimicrobial properties of tissue conditioner containing silver doped bioactive glass nanoparticles (Ag-BG NPs) in vitro against three oral pathogens. A novel bioactive glass (BG) nanoparticles (NPs) with different Ag weight percentages of 0.6, 1.2, 3 and 4 wt% was prepared via a modified sol-gel method. Characterization of Ag-BG NPs was carried out using transmission electron microscopy (TEM), Fourier transformer infrared spectrophotometer (FTIR). Antimicrobial activities of the NPs were estimated. Also, Ag + ions release was measured using an inductively coupled plasma optical emission spectroscopy (ICP/OES). The 4% Ag-BG NPs was incorporated into the tissue conditioner (TC) for the preparation of the composite specimens (TC/Ag BG 4%). The dispersion of the NPs was evaluated using SEM/EDX. Ag + ion release and antimicrobial activities were evaluated. Finally, cell cytotoxicity was assessed using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay on normal human fibroblast (BJ1). Data analysis was performed using one-way ANOVA, and Tukey's post hoc test. The Ag-BG NPs (4%) exhibited the highest statistical significant mean inhibition value against selected pathogens. A novel Ag-BG NPs with antimicrobial properties with gradual release of Ag + were developed. However, the antimicrobial activity was lost when it was incorporated into the tissue conditioner.

No abstract

No abstract