Mechanical-physicochemical properties and biocompatibility of catechin-incorporated adhesive resins

Abstract Several anti-proteolytic dentin therapies are being exhaustively studied in an attempt to reduce dentin bond degradation and improve clinical performance and longevity of adhesive restorations. Objectives This study assessed the effect of epigallocatechin-3-gallate (EGCG) on long-term bond strength when incorporated into adhesives. Material and Methods Adhesive systems were formulated with EGCG concentrations of 0 wt%: (no EGCG; control); 0.5 wt% EGCG; 1.0 wt% EGCG, and 1.5 wt% EGCG. Flexural strength (FS), modulus of elasticity (ME), modulus of resilience (MR), compressive strength (CS), degree of conversion (DC), polymerization shrinkage (PS), percentage of water sorption (%WS), percentage of water solubility (%WL) and cytotoxicity properties were tested. Dentin microtensile bond strength (µTBS) was evaluated after 24 h and again after 6 months of water storage. The adhesive interface was analyzed using scanning electron microscopy (SEM). Results No significant differences were found among the groups in terms of FS, ME, MR, CS and PS. EGCG-doped adhesives increased the DC relative to the control group. EGCG concentrations of 1.0 wt% and 0.5 wt% decreased the WS of adhesives. WL decreased in all cases in which EGCG was added to adhesives, regardless of the concentration. EGCG concentrations of 1.0 wt% and 0.5 wt% reduced cytotoxicity. EGCG concentrations of 1.0 wt% and 0.5 wt% preserved µTBS after 6 months of storage, while 1.5 wt% EGCG significantly decreased µTBS. SEM: the integrity of the hybrid layer was maintained in the 0.5 wt% and 1.0 wt% EGCG groups. Conclusion EGCG concentrations of 1.0 wt% and 0.5 wt% showed better biological and mechanical performance, preserved bond strength and adhesive interface, and reduced cytotoxicity.

Long-term bonding efficacy of adhesives containing benzodioxioles as alternative co-initiators

Abstract This study evaluated the three-year lifespan of the bond to dentin of experimental self-etch adhesives containing benzodioxole derivatives - 1,3-benzodioxole (BDO) and piperonyl alcohol (PA) - as co-initiator alternative to amines. Adhesive resins were formulated using Bis-GMA, TEGDMA, HEMA, camphorquinone and different co-initiators: BDO, PA or ethyl 4-dimethylamino benzoate (EDAB - amine). An experimental self-etch primer was used to complete the two-step, self-etch adhesive system. Clearfil SE Bond (CSE) was used as commercial reference. Bond strength to human dentin was assessed by microtensile bond strength (µTBS) test, and failure mode was classified. Morphology of the dentin bonding interface was assessed via scanning electron microscopy (SEM). Irrespective of the dental adhesives evaluated, µTBS was higher after 24 hours compared with that after 1.5 and 3 years (p ≤ 0.001). However, adhesives with BDO and PA as co-initiators showed significantly higher bond strength than the bonding resin with EDAB (p ≤ 0.002), independent of the time evaluated. The commercial adhesive CSE showed similar bond strength compared with the other groups (p ≥ 0.05). Mixed failures were mainly observed after 24 hours, while adhesive failures were more frequently observed after 1.5 and 3 years. No notable differences in homogeneity and continuity along the bonded interfaces were detected among the materials in the SEM analysis. In conclusion, benzodioxole derivatives are feasible alternative co-initiators to tertiary amine in camphorquinone-based self-etching dental adhesive formulations.

Influence of a hydrophobic monomer on the physical and mechanical properties of experimental surface sealants

Abstract This study evaluated the effect of adding the hydrophobic monomer 1,12 dodecanediol dimethacrylate (DDDMA) to experimental sealants with and without thermocycling on degree of conversion (DC), water sorption (WS), water solubility (WSB), color stability (ΔE), and micro-shear bond strength (μSBS). Five experimental and one commercially available sealant (Bisco - BIS) were tested. The experimental sealants were formulated by mixing different percentages of DDDMA monomers and urethane dimethacrylate (UDMA). The photoinitiator system was composed by camphorquinone (CQ) and tertiary amine 4-ethyl benzoate dimetilamiono (EDBA). Ethanol was used as a solvent. The experimental groups were named sequentially according to the monomeric content (DDDMA/UDMA): S40/40 (40/40), S50/30 (50/30), S60/20 (60/20), S70/10 (70/10) and S80/0 (80/0). Data were analyzed separately by one-way ANOVA, followed by Tukey's test (p<0.05). The values of DC ranged from 94.59% (S40/40) to 54.02% (S80/10). BIS showed the highest WS value (p<0.05) and S40/40, S50/30, S60/20 and S80/0 showed the lowest WS values of all tested sealants. WSB values ranged from 7.88 µg/mm3 (BIS) to 13.27 µg/mm3 (S70/10). The highest ΔE value was 11.05±2.88 for BIS and the highest μSBS value was found for S60/20. No significant difference was observed in bond strength between sealants and bovine enamel after thermocycling. Adding DDDMA to the composition of surface sealants can improve its performance, once the monomer increased the degree of conversion and the color stability.

Influence of Different Concentration and Ratio of a Photoinitiator System on the Properties of Experimental Resin Composites

Abstract The aim in this study was to evaluate the influence of different ratio of camphorquinone/tertiary amine concentration on the flexural strength (FS), elastic modulus (EM), degree of conversion (DC), yellowing (YL), water sorption (WS) and water solubility (WSL) of experimental composites. Thus, acrylate blends were prepared with different camphorquinone (CQ) and amine (DABE) concentrations and ratios by weight: (CQ/DABE%): 0.4/0.4% (C1), 0.4/0.8% (C2), 0.6/0.6% (C3), 0.6/1.2% (C4), 0.8/0.8% (C5), 0.8/1.6% (C6), 1.0/1.0% (C7), 1.0/2.0% (C8), 1.5/1.5% (C9), 1.5/3.0% (C10). For the FS and EM, rectangular specimens (7x2x1 mm, n=10) were photo-activated by single-peak LED for 20 s and tested at Instron (0.5 mm/min). Then, the same specimens were evaluated by FTIR for DC measurement. For YL, disks (5x2 mm, n=10) were prepared, light-cured for 20 s and evaluated in spectrophotometer using the b aspect of the CIEL*a*b* system. For WS and WSL, the volume of the samples was calculated (mm³). For WS and WSL, composites disks (5x0.5 mm, n=5) were prepared. After desiccation, the specimens were stored in distilled water for 7 days and again desiccated, in order to measure the WS and WSL. Data were submitted to one-way ANOVA and Tukey's test (5%). The groups C8, C9 and C10 showed higher DC, EM and YL means, compared to other composites. Therefore, the FS and WS values were similar among all groups. Also, C1, C2 and C3 presented higher WSL in 7 days, compared to other composites. In general, higher concentrations of camphorquinone promoted higher physical-mechanical properties; however, inducing higher yellowing effect for the experimental composites

Resumo O objetivo foi avaliar a influência da concentração e proporção de canforoquinona (CQ)/amina terciária (DABE) na resistência à flexão (RF), módulo flexural (MF), grau de conversão (GC), amarelamento (AM), sorpção (SA) e solubilidade em água (SL) de compósitos experimentais. Blendas acrilatas foram preparadas com diferentes concentrações e proporções de CQ/DABE em peso, como segue: (CQ/DABE%): 0,4/0,4% (C1); 0,4/0,8% (C2); 0,6/0,6% (C3); 0,6/1,2% (C4); 0,8/0,8% (C5); 0,8/1,6% (C6); 1,0/1,0% (C7); 1,0/2,0% (C8); 1,5/1,5% (C9); 1,5/3,0% (C10). Para RF e MF, espécimes retangulares (7x2x1 mm, n=10) foram fotoativados com LED de pico único (Radii Cal) por 20 s e testados em máquina Instron (0,5 mm/min). Após, o GC dos mesmos espécimes (fragmentos) foi mensurado por FTIR. Para AM, discos de compósito (5x2 mm, n=10) foram preparados, fotoativados por 20 s e imediatamente avaliados em espectrofotômetro, considerando o aspecto b do sistema CIEL*a*b*. Para SA e SL, discos de compósito (5x0,5 mm, n=5) foram preparados e seus volumes calculados (mm³). Após desidratação, as amostras foram pesadas e armazenadas em água destilada por 7 dias, pesadas e novamente desidratadas e pesadas, para se calcular o SA e SL. Os dados foram submetidos a one-way ANOVA e teste de Tukey (5%). Os grupos C8, C9 e C10 mostraram maior GC, MF e AM, comparado aos outros grupos. No entanto, RF e SA foram similares entre todos os grupos. Ainda, C1, C2 e C3 apresentaram maior SL em 7 dias comparado aos outros grupos. Em geral, maiores concentrações de CQ promoveram melhores propriedades físico-mecânicas; no entanto, levaram ao maior amarelamento dos compósitos.

Mechanical properties, water sorption characteristics, and compound release of grape seed extract-incorporated resins

Abstract Objective This study evaluated the effect of grape seed extract (GSE) incorporation on the mechanical properties, water sorption, solubility, and GSE release from the experimental adhesive resins. Material and Methods An experimental comonomer mixture, consisting of 40% Bis-GMA, 30% Bis MP, 28% HEMA, 0.26% camphorquinone and 1% EDMAB, was used to prepare four GSE-incorporated adhesive resins at concentrations of 0.5, 1, 1.5, and 2 wt%. The neat resin without GSE was used as the control. Six resin beams (25 mm x 2 mm x 2 mm) per group were prepared for flexural strength and modulus of elasticity evaluations using a universal testing machine at a crosshead speed of 1 mm/min. Five disks (6 mm in diameter and 2 mm in thickness) per group were used for microhardness measurements using a Leitz micro-hardness tester with Leica Qgo software. Five disks (7 mm in diameter and 2 mm in thickness) per group were prepared and stored in deionized water for 28 days. Water sorption, solubility, and GSE release in deionized water were calculated for each GSE-incorporated adhesive at the end of 28th day. Data was evaluated using one-way ANOVA and Tukey multiple comparisons. Results Flexural strength, modulus of elasticity and microhardness of GSE-incorporated adhesive decreased significantly with incorporation of 1.5% of GSE (p<0.05). Addition of GSE had no effect on the water sorption of the adhesive resins (p=0.33). The solubility of the resin also increased significantly with incorporation of 1.5% of GSE (p<0.05). Quantities of GSE release increased with increased concentration of GSE in the adhesive resin. Conclusion Up to 1% of GSE can be incorporated into a dental adhesive resin without interfering with the mechanical properties or solubility of the resins.

[Phytochemical and morpho-physiological changes lavender (lavandula officinalis l.) in response to different culture media]

Background: Since the essential oil of lavender [Lavandula officinalis L.] was used for the treatment of diseases related to the nervous system and rheumatism, phytochemical evaluation of this plant is essential especially in terms of cultivation and production

Objective: This study was conducted to investigate the effect of different culture media on the amount of essential components, chlorophyll content, nutrients, growth characteristics, and rooting of lavender

Methods: The experiment was done the basis of randomized complete blocks design [RCBD] in 10 treatments and 3 replications. Substrates and culture media for plant production in this study were Ml; sand, M2; sandiperlite [2:1], M3; sand:peat-moss [2:1], M4; sand:vermicompost [2:1], M5; sand:perlite:peat-moss [2:1:1], M6; sand:perlite:vermicompost [2:1:1], M7; sand:peat-moss:vermicompost [2:1:1] M8; sand:vermicompost:peat-moss:perlite [2:1:1:2], M9; sand:vermicompost:peat-moss:perlite [4:1:1:2], and M10; sand:vermicompost:peat-moss:perlite [6:1:1:2]

Results: Results showed that culture media had significant effect on the all characteristics of rooting, chlorophyll and nutrient content and essential oil components in lavender plants. Limonene, borneol, and camphor were the highest amount of essential oil compounds in lavender, respectively

The highest content of limonene and oxygenated monoterpenes in Ml, rooting percentage and number of main root in M3, camphor and chlorophyll content and root dry weight in M5, borneol content in M8, and hydrocarbon monoterpenes in M10 were observed. Conclusion: The application of different culture media in the production and propagation of lavender in addition to changes in morpho-physiological characteristics of lavender can directly alter the properties of essential oil and phytochemical compounds

Activation of transient receptor potential vanilloid 3 by the methanolic extract of Schisandra chinensis fruit and its chemical constituent γ-schisandrin

Transient receptor potential vanilloid 3 (TRPV3) is a non-selective cation channel with modest permeability to calcium ions. It is involved in intracellular calcium signaling and is therefore important in processes such as thermal sensation, skin barrier formation, and wound healing. TRPV3 was initially proposed as a warm temperature sensor. It is activated by synthetic small-molecule chemicals and plant-derived natural compounds such as camphor and eugenol. Schisandra chinensis (Turcz.) Baill (SC) has diverse pharmacological properties including antiallergic, anti-inflammatory, and wound healing activities. It is extensively used as an oriental herbal medicine for the treatment of various diseases. In this study, we investigated whether SC fruit extracts and seed oil, as well as four compounds isolated from the fruit can activate the TRPV3 channel. By performing whole-cell patch clamp recording in HEK293T cells overexpressing TRPV3, we found that the methanolic extract of SC fruit has an agonistic effect on the TRPV3 channel. Furthermore, electrophysiological analysis revealed that γ-schisandrin, one of the isolated compounds, activated TRPV3 at a concentration of 30 µM. In addition, γ-schisandrin (~100 µM) increased cytoplasmic Ca²⁺ concentrations by approximately 20% in response to TRPV3 activation. This is the first report to indicate that SC extract and γ-schisandrin can modulate the TRPV3 channel. This report also suggests a mechanism by which γ-schisandrin acts as a therapeutic agent against TRPV3-related diseases.

Evaluation of phenyl-propanedione on yellowing and chemical-mechanical properties of experimental dental resin-based materials

ABSTRACT Objective To evaluate the influence of phenyl-propanedione on yellowing and chemical-mechanical properties of experimental resin-based materials photoactivated using different light curing units (LCUs). Material and Methods Experimental resin-based materials with the same organic matrix (60:40 wt% BisGMA:TEGDMA) were mechanically blended using a centrifugal mixing device. To this blend, different photoinitiator systems were added in equimolar concentrations with aliphatic amine doubled by wt%: 0.4 wt% CQ; 0.38 wt% PPD; or 0.2 wt% CQ and 0.19 wt% PPD. The degree of conversion (DC), flexural strength (FS), Young’s modulus (YM), Knoop hardness (KNH), crosslinking density (CLD), and yellowing (Y) were evaluated (n=10). All samples were light cured with the following LCUs: a halogen lamp (XL 2500), a monowave LED (Radii), or a polywave LED (Valo) with 16 J/cm2. The results were analysed by two-way ANOVA and Tukey’s test (α=0.05). Results No statistical differences were found between the different photoinitiator systems to KNH, CLS, FS, and YM properties (p≥0.05). PPD/CQ association showed the higher DC values compared with CQ and PPD isolated systems when photoactivated by a polywave LED (p≤0.05). Y values were highest for the CQ compared with the PPD systems (p≤0.05). Conclusion PPD isolated system promoted similar chemical and mechanical properties and less yellowing compared with the CQ isolated system, regardless of the LCU used.

Exopolysaccharide dispelled by calcium hydroxide with volatile vehicles related to bactericidal effect for root canal medication

ABSTRACT Objective: Enterococcus faecalis is the dominant microbial species responsible for persistent apical periodontitis with ability to deeply penetrate into the dentin. Exopolysaccharides (EPS) contribute to the pathogenicity and antibiotic resistance of E. faecalis. Our aim was to investigate the antimicrobial activity of calcium hydroxide (CH), camphorated parachlorophenol (CMCP), and chlorhexidine (CHX) against E. faecalis in dentinal tubules. Material and Methods: Decoronated single-canal human teeth and semicylindrical dentin blocks were incubated with E. faecalis for 3 weeks. Samples were randomly assigned to six medication groups for 1 week (n=10 per group): CH + 40% glycerin-water solution (1:1, wt/vol); CMCP; 2% CHX; CH + CMCP (1:1, wt/vol); CH + CMCP (2:3, wt/vol); and saline. Bacterial samples were collected and assayed for colony-forming units. After dentin blocks were split longitudinally, confocal laser scanning microscopy was used to assess the proportion of viable bacteria and EPS production in dentin. Results: CMCP exhibited the best antimicrobial activity, while CH was the least sensitive against E. faecalis (p<0.05). CHX showed similar antimicrobial properties to CH + CMCP (1:1, wt/vol) (p>0.05). CH combined with CMCP inhibited EPS synthesis by E. faecalis, which sensitized biofilms to antibacterial substances. Moreover, increasing concentrations of CMCP decreased EPS matrix formation, which effectively sensitized biofilms to disinfection agents. Conclusion: The EPS matrix dispelled by CH paste with CMCP may be related to its bactericidal effect; the visualization and analysis of EPS formation and microbial colonization in dentin may be a useful approach to verify medicaments for antimicrobial therapy.

Biotransformation of (-)-alpha-Pinene by Whole Cells of White Rot Fungi, Ceriporia sp. ZLY-2010 and Stereum hirsutum

Two white rot fungi, Ceriporia sp. ZLY-2010 (CER) and Stereum hirsutum (STH) were used as biocatalysts for the biotransformation of (-)-alpha-pinene. After 96 hr, CER converted the bicyclic monoterpene hydrocarbon (-)-alpha-pinene into alpha-terpineol (yield, 0.05 g/L), a monocyclic monoterpene alcohol, in addition to, other minor products. Using STH, verbenone was identified as the major biotransformed product, and minor products were myrtenol, camphor, and isopinocarveol. We did not observe any inhibitory effects of substrate or transformed products on mycelial growth of the fungi. The activities of fungal manganese-dependent peroxidase and laccase were monitored for 15 days to determine the enzymatic pathways related to the biotransformation of (-)-alpha-pinene. We concluded that a complex of enzymes, including intra- and extracellular enzymes, were involved in terpenoid biotransformation by white rot fungi.

STUDIES ON THE CONSTITUENTS OF ARTEMISIA ANNUA L / 药学学报

Six crystalline components were isolated from the lipophilic fraction of Artemisia annua L. They have been identified as four sesquiterpenes, one flavonol and one coumarin. Qinghaosu I and III are new sesquiterpenes. Five main constituents, camphene, iso-artemisia ketone, 1-camphor, β-carophyllene, and β-pinene were identified from the volatile oil of this herb.

Chemical Composition of the Leaf Essential Oils of Croton zambesicus Müll.-Arg. Grown in Lagos, South-West Nigeria.

The chemical composition of the leaf essential oil of Croton zambesicus Müll.-Arg., collected from Agbara-Lagos, Nigeria, was analysed by means of Gas chromatography flame ionization detector (GC-FID) and Gas chromatography coupled with Mass spectrometry (GC-MS). Sixty constituents accounting for 98.9% of the total oil contents were identified from the oil sample. The classes of compounds identified in the oil were monoterpene hydrocarbons (35.3%), oxygenated monoterpenes (22.9%), sesquiterpene hydrocarbons (32.4%) and oxygenated sesquiterpenes (5.6%). The oil was dominated by β-pinene (15.1%), β-caryophyllene (12.6%), germacrene D (10.9%), camphor (7.3%), linalool (7.0%), sabinene (6.4%) and α-pinene (5.2%). Aims: The aim of the research is to investigate the volatile constituents from C. zambesicus harvested in Lagos, Nigeria. Study Design: Extraction of essential oil from the air-dried leaf samples of C. zambesicus and investigation of its chemical constituents. Place and Duration of Study: Leaf samples of C. zambesicus were collected from Agbara, Lagos, on April 2011. Methodology: Air-dried and pulverized leaves were hydrodistilled in a Clevenger-type apparatus to obtained pale yellow volatile oil whose chemical constituents was analyzed by GC and GC/MS. Results: A total of sixty compounds were identified, amounting to 98.9%of the total oil contents. The major were compounds β-pinene (15.1%), β-caryophyllene (12.6%), germacrene D (10.9%) and camphor (7.3%). Variations in compositional pattern were observed between this result and the previous studies. Conclusion: The literature about the C. zambesicus indicates a high variability in the chemical composition of the essential oils.

Componentes volátiles de Eriope crassipes, Hyptis conferta, H. dilatata, H. brachiata, H. suaveolens y H. mutabilis (Lamiaceae) / Volatile compounds of analysis of Eriope crassipes, Hyptis conferta, H. dilatata, H. brachiata, H. suaveolens y H. mutabilis (Lamiaceae)

This work presents the analysis by GC-MS of volatile metabolites of six Lamiaceae from Arauca (Colombia). In stems and leaves of Eriope crassipes were determined as the most abundants: citronellic acid (53,8 percent and 66,2 percent), and methyl citronellate (15,7 percent and 14,5 percent). In the inflorescences of Hyptis conferta were identified: t-cadinol (49,4 percent), and caryophyllene oxide (13,0 percent). From leaves and flowers of Hyptis dilatata were found: delta-3-carene (11,0 percent and 0,5 por ciento), camphor (43,8 percent and 12,2 percent), bornyl acetate (3,2 percent and 25,5 percent), E-caryophyllene (12,8 percent and 22,3 percent), and palustrol (6,0 percent and 10,3 percent). In the leaves of Hyptis brachiata were recognized: E-caryophyllene (8,3 percent), alpha-humulene (19,8 percent), and germacrene D (13,0 percent). The principal compounds in leaves and flowers of Hyptis suaveolens were: alpha-phellandrene (9,4 percent and 0,4 percent), limonene (10,5 percent and 2,5 percent), 1,8-cineole (1,3 percent and 15,2 por ciento), fenchone (10,8 por ciento and tr), E-caryophyllene (26,3 por ciento and 8,0 por ciento), and germacrene D (6,7 por ciento and 14,0 por ciento). In the leaves of Hyptis mutabilis were determined: sabinene (6,6 percent) beta-elemene (6,8 percent), germacrene D (14,9 percent), beta-selinene (8,8 percent), alpha-selinene (9,1 percent), and bicyclogermacrene (6,1 percent), as the most abundants.

Este trabajo presenta el análisis por GC-MS de los metabolitos volátiles de seis Lamiaceae recolectadas en Arauca (Colombia). En tallos y hojas de Eriope crassipes se determinaron como mayoritarios: ácido citronélico (53,8 por ciento y 66,2 por ciento), y citronelato de metilo (15,7 por ciento y 14,5 por ciento). En las inflorescencias de Hyptis conferta se identificaron: t-cadinol (49,4 por ciento), y óxido de cariofileno (13,0 por ciento). En hojas y flores de Hyptis dilatata se encontraron: delta-3-careno (11,0 por ciento y 0,5 por ciento), alcanfor (43,8 por ciento y 12,2 por ciento), acetato de bornilo (3,2 por ciento y 25,5 por ciento), E-cariofileno (12,8 por ciento y 22,3 por ciento), y palustrol (6,0 por ciento y 10,3 por ciento). En las hojas de Hyptis brachiata se reconocieron: E-cariofileno (8,3 por ciento), alfa-humuleno (19,8 por ciento), y germacreno D (13,0 por ciento). Los compuestos principales en hojas y flores de Hyptis suaveolens fueron: alfa-felandreno (9,4 por ciento y 0,4 por ciento), limoneno (10,5 por ciento y 2,5 por ciento), 1,8-cineol (1,3 por ciento y 15,2 por ciento), fenchona (10,8 por ciento y tr), E-cariofileno (26,3 por ciento y 8,0 por ciento), y germacreno D (6,7 por ciento y 14,0 por ciento). En las hojas de Hyptis mutabilis se determinaron: sabineno (6,6 por ciento), beta-elemeno (6,8 por ciento), germacreno D (14,9 por ciento), beta-selineno (8,8 por ciento), alfa-selineno (9,1 por ciento), y biciclogermacreno (6,1 por ciento), como los más abundantes.

Acute toxicity assessment of camphor in biopesticides by using Daphnia magna and Danio rerio

OBJECTIVES: An ecofriendly alternative to chemical pesticides is bio-pesticides, which are derived from natural sources. The interest in bio-pesticides is based on the disadvantages associated with chemical pesticides. METHODS: We conducted acute toxicity assessments of camphor, a major component of bio-pesticides, by using Daphnia magna (D. magna) as well as assessed the morphological abnormalities that occurred in Danio rerio (D. rerio) embryos. RESULTS: The median effective concentration of camphor on D. magna after 48 hours was 395.0 muM, and the median lethal concentration on D. rerio embryos after 96 hours was 838.6 muM. The no observed effect concentration and predicted no effect concentration of camphor on D. magna, which was more sensitive than D. rerio, were calculated as 55.2 muM and 3.95 muM, respectively. Morphological abnormalities in D. rerio embryos exposed to camphor increased over time. Coagulation, delayed hatching, yolk sac edema, pericardial edema, and pigmentation of embryos mainly appeared between 24 and 48 hours. Further, symptoms of scoliosis and head edema occurred after 72 hours. In addition, bent tails, ocular defects and collapsed symptoms of fertilized embryonic tissue were observed after 96 hours. CONCLUSIONS: The camphor toxicity results suggest that continuous observations on the ecosystem are necessary to monitor toxicity in areas where biological pesticides containing camphor are sprayed.

Reabsorción apical posterior a la aplicación de fuerzas ortodónticas. Diagnóstico y tratamiento: a propósito de un caso clínico / Apical resorption after orthodontic force application. Diagnosis and treatment: a propos of a clinical case

En el presente artículo se describe un caso clínico de incisivos afectados por reabsorción apical externa. Dado que el tratamiento de la reabsorción requiere la aplicación de numerosas maniobras apropiadas, se comenzó por realizar el diagnóstico clínico-radiográfico adecuado. El paciente presentaba ortodoncia fija superior e inferior, edema en el fondo de surco de la zona anteroinferior, test de vitalidad negativo en los dientes 31 y 41, incisivos inferiores asintomáticos y con respuesta positiva a las pruebas de vitalidad. Concluido el diagnóstico, se aplicó un procedimiento alternativo que consistió en la inmediata supresión de las fuerzas ortodónticas, aperturas camerales en las piezas 31 y 41, medicación y cronificación del proceso agudo. Con el fin de lograr la reparación de las piezas afectadas, estos dientes fueron tratados con sesiones intermedias de pasta alcalina, compuesta por hidróxido de calcio, iodoformo y clorofenol alcanforado. Al observar en los controles silencio clínico y comienzo de neoformación ósea en la zona, se realizó la terapia definitiva. Los resultados obtenidos muestran que si bien los tratamientos de dientes con reabsorción apical externa son intervenciones complicadas, son posibles de tratar sin necesidad de recurrir a intervenciones quirúrgicas, aportando beneficios psicológicos y económicos para el paciente.

Ex-vivo Effect of Intracanal Medications Based on Ozone and Calcium Hydroxide in Root Canals Contaminated with Enterococcus faecalis

This ex vivo study evaluated the antibacterial effect of intracanal medications in root canals contaminated with Enterococcus faecalis. Fifty single-rooted human teeth were contaminated with E. faecalis (ATCC 29212) and incubated at 37°C for 21 days. The specimens were randomly divided into 5 groups according to the intracanal medication used: OZ-PG: ozonized propylene glycol; CH/CPMC: calcium hydroxide/camphorated paramonochlorophenol; OZ-PG/CH ozonized PG/CH; PC: positive control group (no medication); and NC: negative control group (no contamination). The samples were collected after 7 days (post-medication) and 14 days (final). Bacterial growth was checked by counting the colony-forming units (CFU). OZ-PG and CH/CPMC reduced significantly the CFU counts compared with PC in the post-medication and final samples, with no statistically significant differences among them. On the other hand, OZ-PG/CH did not reduce significantly the number of bacteria compared with PC. In conclusion, among the evaluated medications OZ-PG and CH/CPMC were the most effective against E. faecalis.

Resumo Este estudo ex vivo avaliou o efeito antibacteriano de medicações intracanal em canais radiculares contaminados com Enterococcus faecalis. Cinquenta dentes humanos unirradiculares foram contaminados com E. faecalis (ATCC 29212) e incubados a 37°C durante 21 dias. Os espécimes foram aleatoriamente divididos em diferentes grupos de acordo com a medicação intracanal utilizada: PG-OZ: propilenoglicol ozonizado; HC/PMCC: hidróxido de cálcio/paramonoclorofenol canforado; PG-OZ/CH; CP: controle positivo (sem medicação); e CN: controle negativo (sem contaminação). As amostras foram coletadas após 7 dias (pós-medição) e 14 dias (final). O crescimento bacteriano foi verificado através da contagem das unidades formadoras de colônias (UFC). PG-OZ e HC/PMCC reduziram estatisticamente o número de bactérias quando comparados com o CP nas amostras pós-medição e final, sem diferenças estatísticas entre si. Por outro lado, PG-OZ/HC não reduziu significativamente o número de bactérias em comparação com o CP. Em conclusão, entre as medicações avaliadas, PG-OZ e HC/PMCC foram as mais eficazes contra E. faecalis. .

Camphor modulates TRPV3 cation channels activity by interacting with critical pore-region cysteine residues

TRPV3 ion channels mediate thermo-transduction, nociception, inflammation and dermatitis in mammals. TRPV1-4 proteins have been shown to have conserved cysteine-residues in the pore-forming regions. These residues participate in channel activation via S-nitrosylation of channel proteins. Camphor is a commonly used ligand for TRPV3 channels. Thus the knowledge about the potential binding/interacting site[s] for camphor will help to design effective and potent analgesic compounds. In an overlap-extension PCR method, following primer-pairs were used to mutate conserved cysteine-residues in the pore-region of TRPV3 channels; GATTGAGAATcCTCCAAGGACAAAAAGGAC, TRPV3-C612S-Fw and GTCCTTGGAGgACTTCTCAATCAGTCAGTGAGG, TRPV3-C612S-Rv primers pair. And for TRPV3-C619S: GGACTCcAGTTCCTATGGCCAGC, TRPV3-C619S-Fw and GCTGGCCATAgGAACTGGAGTCC, TRPV3-C619S-Rv respectively. All cDNA constructs were confirmed by DNA-sequencing and used to make cRNAs. Oocytes expressing mTRPV3-C619S and mTRPV3-C612S mutant channels were challenged with 2-APB [1 mM], camphor [10 mM] and dihydrocarveol [10 mM] either at -40 mV or +40 mV holding potentials in voltage-clamp experiments. Responses of both mutants to 2-APB were similar to wild-type mTRPV3. Interestingly, responses to camphor were totally lost in mTRPV3-C619S mutant, while responses to dihydrocarveol remained intact. In contrast mTRPV3-C612S displayed slightly altered [16 +/- 2% reduction] phenotype with respect to camphor sensitivity. It is concluded that pore-region cysteines play critical role in camphor sensitivity of TRPV3 ion channels

Photoelastic evaluation of the effect of composite formulation on polymerization shrinkage stress

We compared polymerization stress in two commercial composites and three experimental composites made using camphorquinone (CQ) and/or phenylpropanedione (PPD) as photoinitiators. The internal surfaces of photoelastic resin discs with cylindrical cavities were roughened and treated with adhesive. Composites were divided into five groups: two commercial composites (Filtek Silorane and Filtek Z250) and three experimental composites with CQ/amine, CQ/PPD/amine, and PPD/amine. Composites were photopolymerized inside cavities, and subjected to photoelastic analysis immediately and at 24 hours and 7 days later using a plane polariscope. Stress created by Silorane (3.08 ± 0.09 MPa) was similar to that of Z250 (3.19 ± 0.13 MPa) immediately after photopolymerization (p > 0.05). After 24 hours and 7 days, Z250 (3.53 ± 0.15 and 3.69 ± 0.10 MPa, respectively) showed higher stress than Silorane (3.19 ± 0.10 and 3.16 ± 0.10 MPa, respectively). Qualitative analysis immediately after photopolymerization showed composite/CQ promoted higher stress than PPD, but stress levels at other evaluated times were statistically similar, varying between 3.45 ± 0.11 MPa and 3.92 ± 0.13 MPa. At 24 hours and 7 days, Silorane created the lowest stress. All photoinitiators created comparable tensions during polymerization.

Effect of CQ-amine ratio on the degree of conversion in resin monomers with binary and ternary photoinitiation systems

OBJECTIVES: This study evaluated the effect of camphorquinone (CQ)-amine ratio on the C=C double bond conversion of resins with binary and ternary photoinitiation systems. MATERIALS AND METHODS: Two monomer mixtures (37.5 Bis-GMA/37.5 Bis-EMA/25 TEGDMA) with binary systems (CQ/DMAEMA in weight ratio, group A [0.5/1.0] and B [1.0/0.5]) and four mixtures with ternary system (CQ/OPPI/DMAEMA, group C [0.1/1.0/0.1], D [0.1/1.0/0.2], E [0.2/1.0/0.1] and F [0.2/1.0/0.2]) were tested: 1 : 2 or 2 : 1 CQ-amine ratio in binary system, while 1 : 1 ratio was added in ternary system. The monomer mixture was cured for 5, 20, 40, and 300 sec with a Demetron 400 curing unit (Demetron). After each exposure time, degree of conversion (DC) was estimated using Fourier transform infrared (FTIR) spectrophotometer (Nicolet 520, Nicolet Instrument Corp.). The results were analyzed by ANOVA followed by Scheffe test, with p = 0.05 as the level of significance. RESULTS: DC (%) was expressed in the order of curing time (5, 20, 40, and 300 sec). Group A (14.63 +/- 10.42, 25.23 +/- 6.32, 51.62 +/- 2.69, 68.52 +/- 2.77); Group B (4.04 +/- 6.23, 16.56 +/- 3.38, 37.95 +/- 2.79, 64.48 +/- 1.21); Group C (16.87 +/- 5.72, 55.47 +/- 2.75, 60.83 +/- 2.07, 68.32 +/- 3.31); Group D (23.77 +/- 1.64, 61.05 +/- 1.82, 65.13 +/- 2.09, 71.87 +/- 1.17); Group E (28.66 +/- 2.92, 56.68 +/- 1.33, 60.66 +/- 1.17, 68.78 +/- 1.30); Group F (39.74 +/- 6.31, 61.07 +/- 2.58, 64.22 +/- 2.29, 69.94 +/- 2.15). CONCLUSION: All the monomers with ternary photoinitiation system showed higher DC than the ones with binary system, until 40 sec. Concerning about the effect of CQ-amine ratio on the DC, group A converted into polymer more than group B in binary system. However, there was no significant difference among groups with ternary system, except group C when cured for 5 sec only.