A hnRNPA2B1 agonist effectively inhibits HBV and SARS-CoV-2 omicron in vivo.

The twenty-first century has already recorded more than ten major epidemics or pandemics of viral disease, including the devastating COVID-19. Novel effective antivirals with broad-spectrum coverage are urgently needed. Herein, we reported a novel broad-spectrum antiviral compound PAC5. Oral administration of PAC5 eliminated HBV cccDNA and reduced the large antigen load in distinct mouse models of HBV infection. Strikingly, oral administration of PAC5 in a hamster model of SARS-CoV-2 omicron (BA.1) infection significantly decreases viral loads and attenuates lung inflammation. Mechanistically, PAC5 binds to a pocket near Asp49 in the RNA recognition motif of hnRNPA2B1. PAC5-bound hnRNPA2B1 is extensively activated and translocated to the cytoplasm where it initiates the TBK1-IRF3 pathway, leading to the production of type I IFNs with antiviral activity. Our results indicate that PAC5 is a novel small-molecule agonist of hnRNPA2B1, which may have a role in dealing with emerging infectious diseases now and in the future.

Clinical outcomes of implant-retained mandibular overdentures using the bar and magnetic attachment systems: an up to 5-year retrospective study.

BACKGROUND: Implant-retained mandibular overdentures (IODs) represent an effective and reliable treatment modality for edentulous patients. The present retrospective study compared the clinical outcomes of IODs using bar attachment (BA) system with those using magnetic attachment (MA) system after functioning for up to 5 years. METHODS: Human subjects treated with IODs between 01-01-2010 and 12-31-2014 were identified from patient records. Of the 54 subjects who met the inclusion criteria, 48 subjects including 26 treated with BA-IODs and 22 with MA-IODs (96 mandibular implants) were recruited for the study. The implant units and prostheses were evaluated individually for peri-implant health. Prosthetic complications and maintenance during follow-up were recorded. The subjects responded to the visual analog scale (VAS) and the Oral Health Impact Profile questionnaires for evaluation of patient satisfaction and oral health-related quality of life (OHRQoL). RESULTS: The survival rates of the implants and prostheses were 96.9% and 95.8%, respectively, over a mean observation period of 48±11.3 (range, 13-64) months. Peri-implant probing depth (PPD) and plaque index (PI) were significantly better for the MA group compared with the BA group (P<0.05), while marginal bone loss (MBL) and sulcus bleeding index (SBI) showed no significant differences (P>0.05). Prosthetic complications and maintenance were attachment-dependent. Most recruited subjects were satisfied with their prostheses. There was no statistically significant difference regarding general patient satisfaction or OHRQoL between the two groups (P>0.05). Nevertheless, patients complained that the BA-IODs were significantly more difficult to clean than the MA-IODs (P<0.05). CONCLUSIONS: IODs have an ideal medium-term outcome irrespective of the attachment design. It is recommended that oral hygiene instructions and regular clinical examination be given to subjects wearing IODs.

Chemical Composition and Acetylcholinesterase Inhibitory Activity of Essential Oils from Piper Species.

The essential oils (EOs) derived from aromatic plants such as Piper species are considered to play a role in alleviating neuronal ailments that are associated with inhibition of acetylcholinesterase (AChE). The chemical compositions of 23 EOs prepared from 16 Piper spp. were analyzed by both gas chromatography with a flame ionization detector (GC-FID) and gas chromatography-mass spectrometry (GC-MS). A total of 76 compounds were identified in the EOs from the leaves and stems of 19 samples, while 30 compounds were detected in the EOs from the fruits of four samples. Sesquiterpenes and phenylpropanoids were found to be rich in these EOs, of which asaricin, caryophyllene, caryophyllene oxide, isospathulenol, (+)-spathulenol, and ß-bisabolene are the major constituents. The EOs from the leaves and stems of Piper austrosinense, P. puberulum, P. flaviflorum, P. betle, and P. hispidimervium showed strong AChE inhibitory activity with IC50 values in the range of 1.51 to 13.9 mg/mL. A thin-layer chromatography (TLC) bioautography assay was employed to identify active compound(s) in the most active EO from P. hispidimervium. The active compound was isolated and identified as asaricin, which gave an IC50 value of 0.44 ± 0.02 mg/mL against AChE, comparable to galantamine with an IC50 0.15 ± 0.01 mg/mL.

Occlusion and Disocclusion Time Changes in Single Unit Crowns Designed by Functional Generated Path Technique: A Randomised Clinical Trial.

Although it is believed that implementation of the functional generated path (FGP) technique can facilitate occlusal surface design for restorations, it has not been objectively compared in situ with the conventional fabrication yet. Therefore, in the present study, a single-blind crossover clinical trial was conducted using T-scan to compare changes in occlusion time (OT) and disocclusion time (DT) of single posterior artificial crowns designed differently using FGP technique (FGP), average-value FGP technique (AVR) and conventional fabrication (CON). Each of the 10 participants took part in the study tried three artificial crowns in different sequences according to a computer generated randomization list. The results objectively revealed that changes in OT and DT were significantly smaller for FGP than CON (P < 0.05) and considerably smaller for AVR than CON, respectively. The subjective feedback and the occlusal adjusting time were better and shorter for FGP and AVR than CON (P < 0.05). No harm to the participants occurred. Overall, FGP is an efficient technique showing more physiological harmonious relationship with the articulating system.

Proteoglycans affect monomer infiltration in the etch-and-rinse bonding technique.

OBJECTIVES: To identify proteoglycans (PGs) and collagen fibrils (CF) within human dentin by means of a dual immunofluorescent labeling technique and to investigate the monomer infiltration of two etch-and-rinse adhesives to tosyl-phenylalanine chloromethyl-ketone (TPCK)-treated trypsin (TRY)-pretreated dentin. METHODS: Thirty-micrometer sections of middle coronal dentin were obtained and etched with 37% phosphoric acid gel for 15 s. After preconditioning with or without TRY digestion, the sections were subjected to dual immunofluorescent labeling and observed with a confocal laser scanning microscope (CLSM). Demineralized dentin matrixes treated with or without TRY were observed with field emission scanning electron microscope (FE-SEM). Two etch-and-rinse adhesives, Adper Single Bond 2 (SB) and Prime & Bond NT (PBNT), were applied to the dentin surfaces that were pretreated with or without TRY. The thickness of the hybrid layers was evaluated under confocal micro-Raman spectroscopy and analyzed with a two-way ANOVA. RESULTS: Green and red fluorescence was used to represent the PGs and the CF that were colocalized in the same section with different distributions. PGs were localized in the lumens of the dentin tubules and in peritubular dentin, while the type-I collagen fibrils were localized in intertubular dentin and peritubular dentin. After preconditioning with TRY digestion, the red fluorescence decreased or disappeared, the organic filaments in the lumens of the dentin tubules disappeared, the tubules were enlarged, and the hybrid layer thickness for adhesives bonded to the TRY-pretreated dentin surfaces were significantly increased (p<0.001 for both SB and PBNT). SIGNIFICANCE: The dual immunofluorescence labeling methodology can be used to study the human dentin matrix without decalcifying the entire dentin fragment. Proteoglycans were localized in the lumens of the dentin tubules and in peritubular dentin, which could depress the infiltration of the adhesive resin monomers. The use of TRY digestion increased the thickness of the hybrid layer created by the tested two-step etch-and-rinse adhesive.

Effect of luting cement and thermomechanical loading on retention of glass fibre posts in root canals.

OBJECTIVES: To evaluate the effect of luting cement and thermomechanical loading on the retention of glass fibre posts in root canals. METHODS: One hundred and forty-four single-rooted human premolars were endodontically treated and restored with RelyX Fibre Posts. The teeth were divided into four groups according to the cements used (Fuji I, Fuji CEM, RelyX Unicem and RelyX ARC). Each group was further divided into two subgroups according to the method of ageing (immediately tested and after thermomechanical loading). Bond strength was evaluated using a pull-out test. Microleakage was examined quantitatively with dye penetration. The dentine-cement-post bonding interface was assessed using scanning electron microscopy. Data were analysed with two-way ANOVA (pull-out test) and Kruskal-Wallis analysis (microleakage). RESULTS: The pull-out bond strength and microleakage were significantly affected by the type of cement and ageing. Although RelyX ARC showed the highest bond strength before thermomechanical loading (p<0.05), the sealing ability of this cement was worse than those exhibited in Fuji CEM and RelyX Unicem (p<0.05). After thermomechanical loading, pull-out strengths of Fuji I and Fuji CEM were significantly increased, whereas that of RelyX ARC group significantly decreased (p<0.05). The sealing ability of Fuji CEM was significantly better than the two resin cement groups (p<0.05) after ageing. CONCLUSION: Fuji CEM demonstrates increased pull-out strength after thermomechanical loading and favourable sealing ability compared with the other cements. CLINICAL SIGNIFICANCE: Resin-modified glass ionomer cements have the potential benefit of achieving long-term retention when used for luting glass fibre post to root canal dentine. So it may be recommended for the cementation of glass fibre post in clinics.

A new fixation method for stick-shaped specimens in microtensile tests: laboratory tests and FEA.

PURPOSE: To introduce a new fixation method for stick-shaped specimens for use in microtensile tests and to evaluate the effect of this new method on microtensile bond strength, failure modes, and stress distribution. MATERIALS AND METHODS: Flat mid-coronal dentin surfaces were prepared on 12 caries-free human third molars and randomly divided into two groups for testing with two dental adhesives (Adper Single Bond 2 [SB2] and Clearfil SE Bond [SEB]). Following adhesive application and composite buildups, the bonded teeth were sectioned into beams. Sticks from each tooth were then equally divided into two subgroups for microtensile bond testing according to the utilized gripping devices (a flat Ciucchi's jig and the experimental setup). Failure modes were examined with a field-emission scanning electron microscope (FESEM). Three-dimensional models of each gripping device and specimen were developed, and stress distributions were analyzed by finite element analysis (FEA). Statistical significance was set at α = 0.05 RESULTS: Compared to those fixed using a flat Ciucchi's jig, sticks fixed with the experimental setup yielded lower bond strength values (p = 0.021 for SB2 and p = 0.007 for SEB) and more mixed failure patterns (p = 0.036 for both SB2 and SEB). In addition, the experimental setup guaranteed a uniaxial tensile force that was perpendicular to the bonding interface and produced a more uniform stress distribution at the bonding interface. CONCLUSION: An experimental setup for fixing microtensile sticks was proposed that was designed to provide a uniform stress distribution at the adhesive interface. FEA and failure mode analysis confirmed such uniform distribution, thus supporting the validity of the bond strength results obtained with this new fixture design.

[The potential effect of proanthocyanidins on the stability of resin-dentin bonds against thermal cycling].

OBJECTIVE: To investigate the potential effect of proanthocyanidins (PA), a natural cross-linker, on the stability of resin-dentin bonds against thermal cycling. METHODS: Ten percent, 15% PA-based preconditioners, and 5% glutaraldehyde were prepared for the transient pretreatment of demineralized dentin before bonding. Specimens without pretreatment were used as negative controls (n = 4 teeth for each group). Microtensile bond strength, failure mode, micromorphologies of resin-dentin interface and the collagen degradation of bonded specimens after thermal cycling were evaluated. RESULTS: After thermal cycling, the microtensile bond strength values of resin-dentin bond in groups pretreated with 15% PA for 120 s and 60 s [(23.09 ± 3.19) and (21.88 ± 3.49) MPa] were significantly higher than that in control group [(15.47 ± 3.78) MPa] (P < 0.05). Mixed fractures were the most prevalent failure mode. Specimens with pretreatment presented compact hybrid layer, while some narrow gaps were found in hybrid layer of non-treated specimens. Collagen biodegradation rates in groups with pretreatment were significantly lower than that in control group (P < 0.05). Among them, specimens pretreated by 15% PA preconditioner for 120 s exhibited the lowest biodegradation rates [(0.316 ± 0.019) mg/g]. CONCLUSIONS: The application of natural cross-linker PA on demineralized dentin reduced the bond degradation against aging by thermal cycling, and can be helpful to create more durable bonds to dentin.

[A study on the bonding properties of four resin cements].

OBJECTIVE: To evaluate the dentin and enamel bonding strength and resin-dentin interfaces of four resin cements. METHODS: Twenty-four sound freshly extracted molars were sectioned with low-speed saw under running water. Two mesial-distal enamel disc and two buccal-lingual dentin discs were sectioned from each molar. Four resin cements (A group: Panavia(TM) F; B group: RelyX(TM) ARC; C group: RelyX(TM) Unicem; D group: Clearfil(TM) SA Cement) were applied to the surface of these enamel and dentin discs according to manufacturers' guidance. The bonded specimen were prepared for shear bond strength test and sectioned occluso-gingivally into two slabs for scanning electron microscopy (SEM) observation. RESULTS: The bonding strength between resin and enamel in B group [(29.38 ± 6.28) MPa] was higher than that in D group [(27.25 ± 7.03) MPa], and both of them were significantly higher than those in A [(22.92 ± 7.13) MPa] and C group [(10.92 ± 3.41) MPa] (P < 0.05). The highest dentin bonding strength was shown in B group [(27.28 ± 6.79) MPa], followed by A [(14.23 ± 6.39) MPa], D [(10.09 ± 3.26) MPa] and C group [(6.43 ± 1.60) MPa, P < 0.05]. CONCLUSIONS: The four resin cements have different enamel or dentin bonding properties.

Nanoleakage and microtensile bond strength at the adhesive-dentin interface after different etching times.

PURPOSE: To evaluate the effect of etching time on the nanoleakage and microtensile bond strength (microTBS) at the interface between etch-and-rise adhesives and dentin. METHODS: Eighty molars were sectioned to expose the superficial dentin and randomly divided into four groups according to the adhesives used: OptiBond Solo (OB), Single Bond (SB), One-Step (OS), and Prime&Bond NT (PB). Within each group, a total-etching technique was applied, and the dentin surfaces were etched for 0, 15, 30 or 60 seconds. Each treated tooth was then sectioned into sticks. A non-trimming microTBS test and TEM observation for nanoleakage were sequentially performed. RESULTS: The degree of nanoleakage increased as etching time increased (P < 0.05). For the OS and PB groups, the highest microTBS values were achieved with 15 seconds of etching, followed by 30, 60 and 0 seconds. For the OB and SB groups, the microTBS values for 15- and 30-second etching times were similar and were both significantly higher than those of 0 and 60 seconds (P < 0.05).

Antibacterial functionalization of an experimental self-etching primer by inorganic agents: microbiological and biocompatibility evaluations.

Antibacterial activities have been demonstrated on oral bacteria with inorganic antibacterial agents (ABAs) after their incorporations into an experimental self-etching primer (ESP) before curing. This study was to assess their biocompatibility and antibacterial activity after curing. Six ABAs were incorporated respectively into ESP for treating specimens. After curing, their bactericidal activities on Streptococcus mutans and influences to the early bacterial colonization were assessed by direct contact and viable count. Systemic toxicity in rats after short-term oral exposure and direct contact cytotoxicity with NIH3T3 fibroblasts were tested. Incorporation of ZnOw AT-83, Longbei antibiotic, Antim-AMS2 or IONPURE-H significantly enhanced the antibacterial effect of ESP after curing, even after 1 month aging. Specimens treated by ESP with ZnOw AT-83, Longbei antibiotic or Antim-AMS2 showed slightly less bacterial adhesion than control. Animal experiments revealed neither toxic signs nor significant differences in body weight gain between control and other groups. Cell vitality or proliferation rates were ranged from 76% to 100% with respect to controls. Basic magnesium hypochlorite, ZnOw AT-83 and ZnOw AT-88 were less toxic. Toxicity only observed in areas beneath the specimens and/or in the direct vicinity of the specimen edge. From microbiological and biocompatibility aspects, the tested ABAs can be effectively incorporated in ESP to provide antibacterial activity against S. mutans. ZnOw AT-83 was the most promising one.

[Measurement and comparison of the spectral transmittance of cerinate porcelain and human enamel].

OBJECTIVE: To measure the spectral transmittance of Cerinate porcelain veneer and enamel in different color and different thickness. METHODS: Samples of Cerinate porcelain veneers were prepared in different thickness (0.50 mm, 0.75 mm, 1.00 mm) and different Vita shade (A1, A2, A3). Enamel samples in shade A2 were made with three thickness (0.50 mm, 0.75 mm, 1.00 mm). A spectrophotometer with spectra range (380-800 nm) was employed to measure the spectral transmittance. RESULTS: Spectral transmittance decreased with the increasing in the thickness of specimens and decreasing in the color darkness. The transmittance of Cerinate porcelain veneer material and enamel in the same color and same thickness hadn't significant difference. CONCLUSION: The key factor to spectral transmittance of porcelain veneer materials is veneer's thickness, and the color of the materials has also some influence on it. Cerinate porcelain veneers can properly recover the transparency of teeth.

[Comparison of dentin nanoleakage among six adhesives].

OBJECTIVE: To evaluate the nanoleakage appearance in 6 dentin adhesives. METHODS: Superficial occlusal dentin of 12 human molars without caries extracted freshly was exposed with 600-grit SiC papers under running water. Six adhesives were applied to dentin surfaces according to the manufacturers' instructions. The bonded teeth were sectioned occluso-gingivally into 0.9-mm-thick serial slabs that were stored in ammoniacal silver nitrate solution in the dark for 24 h and prepared for transmission electron microscope. The extent of nanoleakage among 6 dentin adhesives was measured and compared using one-way ANOVA. RESULTS: The nanoleakage was observed obviously at the dentin-resin interfaces of all 6 adhesives. The average dentin nanoleakage values of Group A [BangDuo, (16.09 +/- 2.08)%], Group B [Single Bond, (13.39 +/- 1.81)%], and Group C [Prime&Bond NT, (11.27 +/- 1.94)%] were all significantly different (P < 0.05). There was no significant difference in the dentin nanoleakage between Group D [B(1), (12.13 +/- 2.11)%] and Group E [Clearfil SE Bond, (12.35 +/- 2.60)%], but both of them were lower than Group F [Adper Prompt, (14.93 +/- 2.67)%]. CONCLUSIONS: The nanoleakage phenomena at the dentin-resin interface were all observed diversely in the contemporary dental adhesives.

Clinical evaluation of 546 tetracycline-stained teeth treated with porcelain laminate veneers.

OBJECTIVE: The purpose of this study was to evaluate the clinical result of 546 tetracycline-stained teeth restored with a porcelain laminate veneer system (Cerinate, Den-Mat, USA) for aesthetic reasons. METHODS: Tetracycline-stained teeth (546) were restored with a porcelain veneer system, and bonded with Ultra Bond resin cement. The restorations were recalled after 0.5, 1.5 and 2.5 years, respectively. Modified Ryge criteria were used to evaluate the veneers marginal adaptation, interfacial staining, secondary caries, postoperative sensitivity and the patients' satisfaction of the colour of the restorations. RESULTS: This study found that 99% veneers had excellent marginal adaptations; and less than 1% veneers required rebonding in the first 6 months; the colour of the veneers was stable and no evident staining was found. Almost all patients were satisfied with the colour match of their restorations 1 year after placement. CONCLUSIONS: The research indicated that the porcelain veneer restoration system under investigation provided a reliable and highly satisfactory choice for the aesthetic restoration of tetracycline-stained teeth.

[Clinical evaluation of 546 tetracycline-stained teeth treated with Cerinate laminate veneers].

OBJECTIVE: The purpose of this study was to evaluate the clinical result of 546 tetracycline-stained teeth corrected with Cerinate porcelain laminate veneer system for esthetic purpose. METHODS: 546 tetracycline-stained teeth were corrected with Cerinate porcelain veneer system, and bonded with Ultra Bond resin cement. The restorations were recalled after 0.5 year, 1.5 years and 2.5 years, respectively. modified Ryge criteria were used to evaluate the veneers marginal adaptation, interfacial staining, secondary caries, postoperative sensitivity and the patients' satisfaction with the shade of the restorations. RESULTS: this study found that 99% veneers had excellent marginal adaptations; and less than 1% veneers were rebonded after debond in the first half year application; the color of the veneers was stable and no evident staining was found. Almost all patients were satisfied with their restoration color after 1 year's application. CONCLUSION: The research indicated that Cerinate porcelain veneer restoration system is a reliable and ideal choice for the correction of tetracycline-stained teeth.