Adjuvant postbiotic administration improves dental caries prognosis by restoring the oral microbiota

Conventional filling therapy fails to fundamentally reduce oral cariogenic bacteria.Thus,oral microbiota follow-up intervention after filling would be necessary for improving dental caries prognosis.We recruited 9 caries-free individuals,and 89 dental caries subjects(5 dropouts).Eighty-nine patients were randomized into three groups:caries(n=8;no treatment),control(n=40;filling),and postbiotics(n=41;filling and 14-day Probio-Eco®intervention).Salivary samples were collected at 0 day(after filling)and 14 days.Our results showed that the diversity of dental caries oral microbiota was significantly increased compared with healthy subjects,and filling could restore a healthier oral microbiota partially and temporarily.Thepostbiotics intervention keeps a low alpha-diversity.Co-occurrence network analysis showed that a more stable oral microbiota structure after postbiotics intervention.Taxonomic and functional annotation of the microbiota revealed that postbiotics co-treatment significantly:increased the relative abundance of Pseudomonas and P.reactans,decreased the relative abundance of Prevotella shahii,and enriched the energy metabolism-related pathways.BugBase-predicted phenotypes inferred to an oral microbiota with decreased potential pathogenic bacteria and increased oxidative stress-tolerant bacteria after postbiotics intervention.Collectively,it suggested that postbiotics co-treatment could be a promising strategy that restores the oral microecological balance for dental caries.

Impact of Dentinal Tubule Orientation on Dentin Bond Strength

This study aimed to determine the impact of dentinal tubule orientation on dentin bond strength to provide a reference for clinical cavity preparation in resin-bonded restoration. Patients aged 13-16 years were selected, including 18 males and 21 females. Forty-eight human maxillary first premolars from orthodontic extractions were chosen to prepare the test models with the dentinal tubule orientations perpendicular and parallel to the bonding substrate. The test models in the vertical and parallel groups were divided into three groups： total-etching with 20% phosphoric acid, total-etching with 35% phosphoric acid and self-etching, with the dentinal tubule surfaces bonded with composite resin blocks in each group. After the standard test models of dentinal tubule-composite resin blocks were placed in distilled water and stored at 37℃ for 24 h, shearing tests were performed using a universal material testing machine at a crosshead speed of 0.5 mm/min. The bond strength values in the vertical group were 19.33＋1.59 MPa for the 20% phosphoric acid group, 21.39±2.34 MPa for the 35% phosphoric acid group, and 16.88±1.54 MPa for the self-etching group. The bond strength values in the parallel group were 24.53±1.99 MPa for the 20% phosphoric acid group, 25.16＋2.88 MPa for the 35% phosphoric acid group, and 20.83±1.99 for the self-etching group. After using same total-etching adhesive, the shear bond strength of the parallel group was higher than that of the vertical group, and the difference was statistically significant （P〈0.05）. Regardless of vertical group or parallel group, the difference in the bond strength value between the total-etching groups and the self-etching group was statistically significant （P〈0.05）. It was concluded that the dentin bonding substrate which was parallel to the direction of the dentin tubule achieved an improved bond strength; the total-etching adhesives achieved higher bond strengths in dentin bond than the self-etching adhesives.

Advances of adipose-derived mesenchymal stem cells-based biomaterial scaffolds for oral and maxillofacial tissue engineering

The management of oral and maxillofacial tissue defects caused by tumors,trauma,and congenital or acquired deformities has been a major challenge for surgeons over the last few decades.Autologous tissue transplantation,the gold standard of tissue reconstruction,is a valid method for repairing the oral and maxillofacial functions and aesthetics.However,several limitations hinder its clinical applications including complications of donor sites,limited tissue volume,and uncertain long-term outcomes.Adipose-derived mesenchymal stem cells(ADMSCs)widely exist in adipose tissue and can be easily obtained through liposuction.Like the bone marrow-derived mesenchymal stem cells(BMSCs),ADMSCs also have the multi-pluripotent potencies to differentiate into osteoblasts,chondrocytes,neurons,and myocytes.Therefore,the multilineage capacity of ADMSCs makes them valuable for cell-based medical therapies.In recent years,researchers have developed many candidates of ADMSCs-based biomaterial scaffolds to cater for the needs of oral and maxillofacial tissue engineering due to their superior performance.This review presents the advances and applications of ADMSCs-based biomaterial scaffolds,and explores their tissue engineering prospects in oral and maxillofacial reconstructions.

Preparation,Structure,Fluorescence,Semiconductor Properties and TDDFT Calculation of a Mononuclear Zinc Complex with Mixed Ligands

A novel zinc complex[ZnL(bipy)(H2O)]×H2O with mixed ligands of 3-hydroxy-2-methylquinoline-4-carboxylic acid(HL)and bipy(bipy=2,2'-bipyridine)was synthesized by solvothermal reaction and its crystal structure was determined by single-crystal X-ray diffraction technique.The title compound crystallizes in the orthorhombic system of Pbca space group,and exists as an isolated mononuclear complex.The intermolecular hydrogen bonds and strongπ…πstacking interactions form a three-dimensional(3-D)supramolecular network.Solid-state photoluminescence spectrum reveals that it shows an emission in the blue region of the light spectrum.Time-dependent density functional theory(TDDFT)calculations reveal that this emission can be attributed to ligand-to-ligand charge transfer(LLCT).Solid-state diffuse reflectance data show that there is a narrow optical band gap of 1.83 eV.

Understanding of stem cells in bone biology and translation into clinical applications

Developments of stem cell biology provide new approaches for understanding the mechanisms of a number of diseases,including osteoporosis.In this mini-review,we highlight two areas that related to stem cells in bone biology.Recent discovery of the role of osteoclast and their stem cells leads to developing a new approach for treatment of osteoporosis with the initial stimulation of cells in osteoclast lineage and followed by sequentially enhanced bone formation.Stimulation on both sides in bone remodeling is expected to achieve a long term effect on bone formation.For bone regeneration,multiple disciplinary collaborations among bone biologists,stem cell biologists and biomaterial scientists are necessary to successfully develop an integrated stem cell therapy that should include stem cells,suitable scaffolds and bioactive factors/small molecular compounds.

A sprayable superhydrophobic dental protectant with photoresponsive anti-bacterial,acid-resistant,and anti-fouling functions

Effective dental care can reduce the incidence of oral diseases(dental caries,dentin sensitivity,tooth discoloration,etc.).However,delayed or inappropriate usage of care tools not only fails to eliminate external adverse stimuli,but sometimes even causes dental injury.Inspired by the traditional culture of“lacquer teeth”,a sprayable superhydrophobic protectant(ZFP)composed of ZnO,fluorine modified nano-silica(FSNs),and polydimethylsiloxane(PDMS)is constructed similar to automobile wax,for routine dental protection.With its superhydrophobic properties,this protective membrane can effectively resist the adhesion of bacteria,proteins,and food residues to the teeth surface.Meanwhile,ZFP exerts stable superhydrophobic selfcleaning properties under external mechanical stimulation,temperature alternation,and acidic environment.In addition,ZnO in ZFP can significantly restrain the growth of dental caries-related bacteria(Streptococcus mutans),with an enhanced antibacterial capacity when combined with yellow light irradiation.Both in vivo and in vitro experiments demonstrate that ZFP is a safe,convenient,and quadruplex-effective dental protectant,which is expected to serve as a promising toothpaste companion for joint maintenance of dental health.

Black fungus derived aerogel with double faced properties

Black fungus derived carbonaceous aerogel (BFA) was prepared via a convenient and energy efficient ultrasonic disposal process. The adsorption experiments of atmospheric pollutants demonstrated the superior adsorbability of black fungus aerogel on PM2.5, PM10 and formaldehyde. More importantly, black fungus aerogel (BFA) exhibited intriguing double-faced properties. We explored properties of each side of the black fungus from three aspects: water contact angle measurements, liquid selective absorption capacity and air pollutant adsorption abilities. The subsequent modification of ZnO nanosheets endowed the prepared black fungus aerogel with several valuable properties, including broad-spectrum antibacterial capability and high-efficient adsorption ability. These valuable characters implied the BFA to be a promising bacteriostat and cleaner for air and water pollution treatment.