Adverse effects of articaine versus lidocaine in pediatric dentistry: a meta-analysis.

Over the last few years, numerous reports have lauded the efficacy of articaine hydrochloride as a local anesthetic (LA) in dental procedures. Numerous studies have shown that articaine outperforms lidocaine in various aspects of dental treatment, leading to its widespread adoption in both adults and children. Despite the publications of comparative studies, there remains a dearth of systematic reviews examining the adverse effects of articaine versus lidocaine in randomized controlled trials. The aim was to assess the available research on the adverse effects of articaine and lidocaine in pediatric dentistry. A comprehensive search was conducted on Cochrane Library, Pubmed, Chinese Biomedical Literature Database (CBM), Embase, Web of Science and China National Knowledge Infrastructure (CNKI). Randomized controlled trials (RCT) that compared articaine with lidocaine in pediatric dentistry were included. Methodological quality assessment and risk of bias were determined for each of the included studies. The Grading of Recommendations, Assessment, Development and Evaluations (GRADE) approach was used to assess the strength of evidence for every research. A total of 333 studies were identified through electronic searches. After conducting primary and secondary assessments, eight studies were included for the final qualitative analysis. We found no difference in the probability of adverse reactions between articaine and lidocaine after treatment in pediatric patients (risk ratio (RR) = 1.08, 95% confidence interval (CI) (0.54-2.15), p = 0.83). However, a high heterogeneity was reported among the outcomes in the investigated studies (I2 = 57%), and the strength of the evidence was classified as "moderate" based on the GRADE approach. Besides, we found no significant difference in the probability of postoperative pain, postoperative soft tissue injury and edema between articaine and lidocaine in pediatric patients following treatment. There was moderate quality evidence suggesting no difference in the occurrence of adverse events between articaine and lidocaine when used for pediatric dental procedures.

Phosgene-free synthesis of hexamethylene-1,6-diisocyanate by the catalytic decomposition of dimethylhexane-1,6-dicarbamate over zinc-incorporated berlinite (ZnAlPO4).

The phosgene-free synthesis of hexamethylene-1,6-diisocyanate (HDI) by the decomposition of dimethylhexane-1,6-dicarbamate (HDU) was carried out on a self-designed fixed-bed catalytic reactor, using zinc-incorporated berlinite (ZnAlPO4) as catalyst, dioctyl phthalate (DOP) as solvent and N2 as carrier gas. Factors influencing the yield of HDI, including the Zn/Al molar ratio, HDU concentration and liquid space velocity (LHSV), were investigated. Under the optimized reaction conditions, i.e., 4.8 wt.% concentration of HDU in DOP, 100ml/min N2 flow rate, 0.09 MPa vacuum, 623K reaction temperature, 1.2h(-1) LHSV and catalyst usage 2.0 g, a 89.4% yield of HDI had been achieved over the ZnAlPO4 (molar ratio Zn/Al=0.04) catalyst. The ZnAlPO4 catalyst was found to exhibit a considerable large on-stream stability and could be repeatedly used in the decomposition of HDU to HDI, after its regeneration.

[Expression of tumor necrosis factor in placenta tissue of pregnant rats with chronic peridontitis].

OBJECTIVE: To examine the expression of tumor necrosis factor in placenta of pregnant rats with chronic periodontitis. METHODS: Twenty Wistar female rats were randomly divided into two groups, control (n = 8) and experimental group (n = 12). The periodontitis model was established in the experimental group. The females and males in the two groups got together four weeks later. Nineteen days after pregnancy all rats were executed and placenta collected. The delivery time and neonatal birth weight were recorded and the pathological changes of periodontal tissue observed. Tumor necrosis factor (TNF) expression was examined in placenta by real-time quantitative polymerase chain reaction analysis. RESULTS: The animal model of chronic periodontitis was successfully established. Experimental group delivered 30 offspring and the control group 56 offspring. The average number of pups born alive per litter in experimental group (4.1 ± 2.2) was significantly lower than that in control group (9.2 ± 2.2), P < 0.05. The birth weight of pups in experimental group [(5.01 ± 0.43) g] was significantly lower than that in the control group [(5.79 ± 0.53) g], P < 0.05. The relative quantitative expression of TNF was (1.807 ± 0.265) in experimental group the and (1.003 ± 0.021) in the control group (P = 0.001). CONCLUSIONS: Chronic periodontitis may be related to preterm low birth weight.

Catalysis over zinc-incorporated berlinite (ZnAlPO4) of the methoxycarbonylation of 1,6-hexanediamine with dimethyl carbonate to form dimethylhexane-1,6-dicarbamate.

BACKGROUND: The alkoxycarbonylation of diamines with dialkyl carbonates presents promising route for the synthesis of dicarbamates, one that is potentially 'greener' owing to the lack of a reliance on phosgene. While a few homogeneous catalysts have been reported, no heterogeneous catalyst could be found in the literature for use in the synthesis of dicarbamates from diamines and dialkyl carbonates. Because heterogeneous catalysts are more manageable than homogeneous catalysts as regards separation and recycling, in our study, we hydrothermally synthesized and used pure berlinite (AlPO4) and zinc-incorporated berlinite (ZnAlPO4) as heterogeneous catalysts in the production of dimethylhexane-1,6-dicarbamate from 1,6-hexanediamine (HDA) and dimethyl carbonate (DMC). The catalysts were characterized by means of XRD, FT-IR and XPS. Various influencing factors, such as the HDA/DMC molar ratio, reaction temperature, reaction time, and ZnAlPO4/HDA ratio, were investigated systematically. RESULTS: The XRD characterization identified a berlinite structure associated with both the AlPO4 and ZnAlPO4 catalysts. The FT-IR result confirmed the incorporation of zinc into the berlinite framework for ZnAlPO4. The XPS measurement revealed that the zinc ions in the ZnAlPO4 structure possessed a higher binding energy than those in ZnO, and as a result, a greater electron-attracting ability. It was found that ZnAlPO4 catalyzed the formation of dimethylhexane-1,6-dicarbamate from the methoxycarbonylation of HDA with DMC, while no activity was detected on using AlPO4. Under optimum reaction conditions (i.e. a DMC/HDA molar ratio of 8:1, reaction temperature of 349 K, reaction time of 8 h, and ZnAlPO4/HDA ratio of 5 (mg/mmol)), a yield of up to 92.5% of dimethylhexane-1,6-dicarbamate (with almost 100% conversion of HDA) was obtained. Based on these results, a possible mechanism for the methoxycarbonylation over ZnAlPO4 was also proposed. CONCLUSION: As a heterogeneous catalyst ZnAlPO4 berlinite is highly active and selective for the methoxycarbonylation of HDA with DMC. We propose that dimethylhexane-1,6-dicarbamate is formed via a catalytic cycle, which involves activation of the DMC by a key active intermediate species, formed from the coordination of the carbonyl oxygen with Zn(II), as well as a reaction intermediate formed from the nucleophilic attack of the amino group on the carbonyl carbon.