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PubMed1980

Neurotoxicity of halogenated O-phenyl O-alkyl alkylphosphonothioates.

Twenty-seven halogenated organophosphorus esters were tested for neurotoxicity in adult hens. Fourteen compounds were overtly neurotoxic, including eight of the eleven methylphosphonothioates, three of seven ethylphosphonothioates, and three of six phosphoramidates, one of which was the commercial herbicide DMPA. Neurotoxic activity varied both with the number of halogen substituents on the phenyl group, and with the identity of the 4-phenyl halogen. Neurotoxic activity also varied with the alkyl group involved in the P-C or P-N bond, and with the identity of the O-alkyl group.

Animals↗

PubMed2006

Cross-over trial of fetal heart rate response to halogen light and vibroacoustic stimulation.

OBJECTIVE: The purpose of this study was to compare the effect of halogen light and vibroacoustic stimulation on fetal heart rate (FHR) responsiveness and on nonstress test (NST) results. METHODS: Sixty consecutively-chosen patients between 33 and 39 weeks of gestation underwent an NST on at least three weekly occasions. Each received halogen light (Vector Compact Sport Spot, Ft Lauderdale, FL, USA), vibroacoustic (SolaTone Artificial Larynx, Temecula, CA, USA), and no stimulation in a randomized order. The transabdominal light or vibroacoustic stimulation lasted for 10 seconds. If no initial FHR acceleration occurred, then the stimulus was repeated 10 minutes later up to a maximum of three times. The investigators who interpreted the FHR patterns were blinded as to the type of stimulus used. RESULTS: Reactive results were present in 171 tests (vibroacoustic: 98.3%; light: 96.6%; none: 93.3%). Compared with no stimulation, the mean difference in time from the onset of recorded "stimulation" to the first FHR acceleration was shorter (p < 0.01) with either light (2.7 minutes, 95% confidence interval (CI) 0.9-4.5 minutes) or vibroacoustic stimulation (2.6 minutes, 95% CI 0.8-4.4 minutes). The mean time difference until a reactive result was also shorter (p < 0.05) with either light (2.7 minutes, 95% CI 0.1-4.9 minutes) or vibroacoustic stimulation (2.4 minutes, 95% CI 0.1-4.7 minutes) than with no stimulation. The need for repeated stimulation during each test was infrequent (light: 5.0%; vibroacoustic: 3.3%). No adverse effect from external stimulation was noted on the FHR tracing. CONCLUSION: Halogen light stimulation is an acceptable alternative to vibroacoustic stimulation in provoking a more rapid fetal heart rate response and in shortening the time before a reactive nonstress test result.

Acoustic Stimulation↗

PubMed1980

Short-term study of the combined effects of mirex, photomirex, and kepone with halogenated biphenyls in rats.

The combined effects of polychlorinated biphenyls (PCBs) or a polybrominated biphenyl (PBB) with mirex, kepone, or photomirex were investigated in rats. Groups of 10 animals were fed diets containing the organohalogens alone or in various combinations for 28 d. Body weight gain and food consumption were not affected by any treatment. Liver weight was increased in the group fed Aroclor 1260/photomirex and in all groups receiving PBB. Hepatic microsomal enzyme activities were elevated in the groups treated with halogenated biphenyls alone; this effect was not potentiated in the presence of mirex-related compounds. Serum biochemical parameters were, for the most part, normal. Hematology tests revealed no abnormalities. Histological changes occurred in the liver, thyroid, and kidney of rats treated with the organohalogens alone or in combination. Liver alterations consisted of central lobular cytoplasmic enlargement, exaggerated periportal perinuclear halos, and increased nuclear hyperchromicity and anisokaryosis. Fatty degeneration was observed in all treated groups. Thyroid changes were characterized by a generalized reduction in follicular size and colloid density with collapse of the follicles. Kidneys suffered mild eosinophilic cytoplasmic inclusions in the proximal convoluted tubule and focal lymphoid aggregates. Histological changes due to PCBs and PBB were aggravated by mirex and related compounds. The degree of damage appeared to be additive rather than potentiative. Mirex and photomirex levels in livers of rats concomitantly exposed to halogenated biphenyls were four to six times higher than those in rats fed mirex-related compounds alone. However, the toxic response in this organ was not potentiated as a result of the increased accumulation. It was concluded that mirex-related compounds at the dose levels studied did not potentiate the effects produced by halogenated biphenyls and vice versa.

Animals↗

PubMed2003

Effects of halogenated anaesthetics on diaphragmatic actin-myosin cross-bridge kinetics.

BACKGROUND: The effects of halogenated anaesthetics on cross-bridge (CB) kinetics are unclear. As halogenated anaesthetics do not markedly modify the intracellular calcium transient in the diaphragm, we used an isolated rat diaphragm preparation to assess the effects of halothane and isoflurane on CB kinetics. METHODS: The effects of halothane and isoflurane (1 and 2 minimum alveolar concentration (MAC)) on rat diaphragm muscle strips were studied in vitro (Krebs-Henseleit solution, 29 degrees C, oxygen 95%/carbon dioxide 5%) in tetanus mode (50 Hz). From the force-velocity curve and using A. F. Huxley's equations, we determined the main mechanical and energetic variables and calculated CB kinetics. RESULTS: At 1 and 2 MAC, isoflurane and halothane induced no significant inotropic effects. Whatever the concentrations tested, halothane and isoflurane did not significantly modify the CB number, the elementary force per CB, the attachment and detachment constants, the duration of the CB cycle and mean CB velocity. CONCLUSION: In the rat diaphragm at therapeutic concentrations, halogenated anaesthetics do not significantly modify CB mechanical and kinetic properties.

Actins↗

PubMed2002

Halogen versus high-intensity light-curing of uncoated and pre-coated brackets: a shear bond strength study.

AIM: To evaluate the shear bond strengths of adhesive pre-coated brackets (APC) and conventional uncoated brackets (Victory) cured with two different light-curing units: a conventional halogen light (Visilux 2) and a micro-xenon light (Aurys). SETTING: Ex vivo study MATERIALS AND METHODS: Sixty freshly extracted bovine permanent mandibular incisors were randomly assigned to one of four groups, each group consisting of 15 specimens. Two groups (one for each type of bracket) were exposed to the halogen light for 20 seconds and used as controls. The remaining two groups were cured with the micro-xenon light for 2 seconds. After 24 hours, all samples were tested in a shear mode on an Instron Machine. Analysis was by two-way ANOVA with Scheffé's test for comparisons, Kaplan-Meier survival estimates, and Cox model. The Chi-square (chi(2)) test was used to determine significant differences in the ARI scores. RESULTS: The mean shear bond strength of the uncoated brackets cured with Visilux 2 was significantly higher than those of all the other groups tested. Both groups cured with Visilux 2 produced significantly higher mean shear bond strengths than those of the corresponding groups cured with Aurys. No statistically significant differences were found between the two groups cured with Aurys. CONCLUSIONS: Compared to halogen light-curing, the micro-xenon light enables the clinician to reduce significantly the curing time of both APC and uncoated brackets, and although significantly lower, their shear bond strengths may be clinically acceptable.

Analysis of Variance↗

PubMed1998

Halogenated anesthetics inhibit Pseudomonas aeruginosa growth in culture conditions reproducing the alveolar environment.

UNLABELLED: We assessed the effects of halogenated anesthetics on Pseudomonas aeruginosa growth in a liquid nutrient broth. Sterile Petri dishes (3.5-cm diameter) were filled with a 1-mL suspension of a Pseudomonas aeruginosa strain and incubated at 37 degrees C. Exposure of bacterial plates to halothane, isoflurane, and enflurane administered at 1 and 2 minimum alveolar anesthetic concentration (MAC) were studied for different exposure times (1, 2, 3, and 4 h) using an airtight chamber. For each time, a control point was obtained. Serial dilutions and agar plates were made, and developed colonies were counted. A significant decrease in bacterial growth was observed from the second hour of exposure to every halogenated anesthetic. For long periods of exposure (3 and 4 h), bacterial growth was significantly reduced in the plates exposed to 2 MAC compared with 1 MAC. The maximal inhibition was observed after a 4-h exposure at 2 MAC and reached 60%, 49%, and 42% for halothane, isoflurane, and enflurane, respectively. We conclude that a decrease in Pseudomonas aeruginosa growth is observed after exposure to halogenated anesthetics, but whether this inhibition is clinically important remains to be demonstrated. IMPLICATIONS: Bacterial pneumonia is a major source of morbidity after general anesthesia. We measured the effects of volatile anesthetics on the growth of Pseudomonas aeruginosa, one of the pathogens most often isolated in hospital-acquired pneumonia. The experiments were performed in vitro in culture conditions reproducing those observed in the alveolar space. Volatile anesthetics inhibited the growth of these bacteria, but the clinical significance of this fact remains to be determined.

Anesthetics, Inhalation↗

PubMed1996

Anesthetic and nonanesthetic halogenated volatile compounds have dissimilar activities on nicotinic acetylcholine receptor desensitization kinetics.

BACKGROUND: The Meyer-Overton rule predicts that an anesthetic's potency will correlate with its oil solubility. A group of halogenated volatile compounds that disobey this rule has been characterized. These compounds do not induce anesthesia in rats at partial pressures exceeding those predicted by the Meyer-Overton rule to be anesthetic. The observation that potentiation of GABA(A) receptor responses by anesthetic and nonanesthetic halogenated volatile compounds correlates with their abilities to induce general anesthesia suggests that this receptor is involved in the mechanism of general anesthesia. However, the GABA(A) receptor is only one member of a superfamily of structurally similar ligand-gated ion channels. This study compares the actions of both anesthetic and nonanesthetic halogenated volatile compounds on another member of this super family of receptors, the nicotinic acetylcholine receptor (nAcChoR). METHODS: The actions of both anesthetic and nonanesthetic compounds on desensitization kinetics were characterized from the time-dependent binding of the fluorescent acetylcholine analogue, Dns-C6-Cho, to the nAcChoR. RESULTS: At concentrations predicted by the Meyer-Overton rule to be equianesthetic, the anesthetics isoflurane and enflurane were significantly more effective than the nonanesthetics 1,2-dichlorohexafluorocyclobutane and 2, 3-dichlorooctafluorobutane in enhancing the fraction of receptors preexisting in the slow desensitized state and increasing the apparent rates of agonist-induced fast and slow desensitization. CONCLUSIONS: The potencies with which anesthetic and nonanesthetic compounds enhance desensitization kinetics in the nAcChoR parallel their in vivo anesthetic potencies. These results support the use of desensitization of the nAcChoR as a mechanistic model for studies of general anesthesia and suggest that an insensitivity to nonanesthetic compounds may be a feature common to members of the superfamily of ligand-gated ion channels.

Anesthetics, Inhalation↗

PubMed2004

Water molecules insert into N-H...Cl-M hydrogen bonds while M-Cl...X-C halogen bonds remain intact in dihydrates of halopyridinium hexachloroplatinates.

The crystal structures of the 3-halopyridinium hexachloroplatinate(IV) dihydrates (HPyX-3)(2)[PtCl(6)]x2H(2)O [(1), X = Br; (2a), (2b), X = I] comprise networks in which the molecular components are linked via N-H...O and O-H...Cl-Pt hydrogen bonds and Pt-Cl...X-C halogen bonds (X = Br, I). The iodo derivative has been isolated in two polymorphic forms. Of particular interest to the understanding of the utility of the hydrogen bonds and M-X...X'-C halogen bonds that propagate the networks in anhydrous salts of this type is that the water molecules insert exclusively into the putative N-H...Cl-Pt hydrogen bonds, while the Pt-Cl...X'-C halogen bonds remain undisrupted by the presence of water molecules.

Journal Article↗

PubMed1989

Removal of halogenated anaesthetics from a closed circle system with a charcoal filter.

Halogenated anaesthetics may be removed from a closed circle system by means of a charcoal filter. With this technique dispersion to the atmosphere and a possibly destructive effect of the halogenated volatiles on the protective layer of ozone is avoided. Removal of halothane or isoflurane with a charcoal filter was studied in a closed circle system connected to an artificial lung. The concentration of anaesthetic (Ct) was recorded in relation to time by an anaesthetic gas monitor interposed between the system and the lung at ventilations of 3, 5, 7 or 9 l/min (v). Based on theoretical considerations, it was expected that Ct = Co.exp (-v/V.t), (V: volume of the system). Analysis of regression demonstrated that the results fitted well to an exponential decrease (R2 greater than 0.94) and the downslope increased with increasing rate of ventilation. However, the slopes deviated significantly from the theoretically predicted slopes, possibly because of adsorption to hoses and bags and unequal distribution of the volatiles in the system. Halothane was eliminated more slowly than isoflurane. This study demonstrates that halogenated volatiles are eliminated in an exponential way following charcoal filtration and the rate depends on the ventilation and type of volatile.

Anesthesia, Closed-Circuit↗

PubMed1975

Halogenated hydrocarbons in New Orleans drinking water and blood plasma.

Volatile organics from New Orleans drinking water and pooled plasma were collected on a solid phenyl ether polymer and analyzed by gas chromatographic and mass spectrometric techniques. Thirteen halogenated hydrocarbons were identified in the drinking water. Five halogenated compounds were found in the plasma. Tetrachloroethylene and carbon tetrachloride were found in both the plasma and the drinking water. Considerable variation in the relative concentrations of the halogenated hydrocarbons was noted from day to day in the drinking water.

Adult↗

PubMed1987

Production of ethane, ethylene, and acetylene from halogenated hydrocarbons by methanogenic bacteria.

Several methanogenic bacteria were shown to produce ethane, ethylene, and acetylene when exposed to the halogenated hydrocarbons bromoethane, dibromo- or dichloroethane, and 1,2-dibromoethylene, respectively. They also produced ethylene when exposed to the coenzyme M analog and specific methanogenic inhibitor bromoethanesulfonic acid. The production of these gases from halogenated hydrocarbons has a variety of implications concerning microbial ecology, agriculture, and toxic waste treatment. All halogenated aliphatic compounds tested were inhibitory to methanogens. Methanococcus thermolithotrophicus, Methanococcus deltae, and Methanobacterium thermoautotrophicum DeltaH and Marburg were completely inhibited by 7 muM 1,2-dibromoethane and, to various degrees, by 51 to 1,084 muM 1,2-dichloroethane, 1,2-dibromoethylene, 1,2-dichloroethylene, and trichloroethylene. In general, the brominated compounds were more inhibitory. The two Methanococcus species were fully inhibited by 1 muM bromoethanesulfonic acid, whereas both Methanobacterium strains were only partly inhibited by 2,124 muM. Coenzyme M protected cells from bromoethanesulfonic acid but not from any of the other inhibitors.

Journal Article↗

PubMed2000

The dynamics of noble gas--halogen molecules and clusters.

The vibrational relaxation of noble gas-halogen van der Waals clusters has been fertile territory for the development of experimental and theoretical tools for state-to-state dynamics studies. Proceeding through the various combinations of noble gas atoms and halogen molecules, one goes from "simple" direct vibrational predissociation, through sequential relaxation pathways, to the statistical intramolecular vibrational relaxation limit. In some cases the vibrational processes dominate, in others electronically nonadiabatic processes, including chemical reactions, interfere. Thus the noble gas-halogen species provide test cases for most of the dynamical processes available to more "normal" molecules. This review discusses the current state-of-the-art for such studies and points to important problems that remain to be solved.

Journal Article↗

PubMed2006

The DNA N-glycosylase MED1 exhibits preference for halogenated pyrimidines and is involved in the cytotoxicity of 5-iododeoxyuridine.

The base excision repair protein MED1 (also known as MBD4), an interactor with the mismatch repair protein MLH1, has a central role in the maintenance of genomic stability with dual functions in DNA damage response and repair. MED1 acts as a thymine and uracil DNA N-glycosylase on T:G and U:G mismatches that occur at cytosine-phosphate-guanine (CpG) methylation sites due to spontaneous deamination of 5-methylcytosine and cytosine, respectively. To elucidate the mechanisms that underlie sequence discrimination by MED1, we did single-turnover kinetics with the isolated, recombinant glycosylase domain of MED1. Quantification of MED1 substrate hierarchy confirmed MED1 preference for mismatches within a CpG context and showed preference for hemimethylated base mismatches. Furthermore, the k(st) values obtained with the uracil analogues 5-fluorouracil and 5-iodouracil were over 20- to 30-fold higher than those obtained with uracil, indicating substantially higher affinity for halogenated bases. A 5-iodouracil precursor is the halogenated nucleotide 5-iododeoxyuridine (5IdU), a cytotoxic and radiosensitizing agent. Cultures of mouse embryo fibroblasts (MEF) with different Med1 genotype derived from mice with targeted inactivation of the gene were evaluated for sensitivity to 5IdU. The results revealed that Med1-null MEFs are more sensitive to 5IdU than wild-type MEFs in both 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide and colony formation assays. Furthermore, high-performance liquid chromatography analyses revealed that Med1-null cells exhibit increased levels of 5IdU in their DNA due to increased incorporation or reduced removal. These findings establish MED1 as a bona fide repair activity for the removal of halogenated bases and indicate that MED1 may play a significant role in 5IdU cytotoxicity.

Animals↗

PubMed2002

Activation of the aryl hydrocarbon receptor by methyl yellow and related congeners: structure-activity relationships in halogenated derivatives.

The aryl hydrocarbon receptor (AhR) is a ligand-activated transcription factor that mediates the biological action of many environmental compounds. Methyl yellow (4-dimethylaminoazobenzene; MY) is a principal azo-dye, and structurally related compounds were subjected to analysis of structure-activity relationships as AhR ligands by using a yeast AhR signaling assay. The effects of halogen-substitution among 23 halogenated MYs on the AhR ligand activity can be summarized as follows: enhancement by halogen-substitution at the ortho-position (2'- and 6'-position), and reduction by substitution at the para-position (4'-position). The greatest enhancement of the ligand activity was observed in 2',6'-dichlorinated MY (13.5-fold of MY), and its AhR ligand activity was very close to that of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) in the present assay system. In the study of compounds structurally related to MY, benzanilide (BA) showed almost the same AhR ligand activity as azobenzene and trans-stilbene. Furthermore, 4'-chlorobenzanilide, in which the length of the molecule is similar to that of MY, enhanced the AhR ligand activity by ortho(2')-chlorine-substitution, and the AhR ligand activity of 2',4'-dichlorobenzanilide was similar to that of 2'-chloro-MY. These results suggest that the amide bond is equivalent to the -N=N- or -CH=CH- double bond for recognition as the ligand by AhR in 1,2-diphenyl-1,2-ene derivatives.

Dose-Response Relationship, Drug↗

PubMed2003

A quantum chemical study of the protonation of phenylphosphine and its halogenated derivatives.

The protonation and methylation of phenylphosphine (C(6)H(5)PH(2)) and its mono-halogenated derivatives have been studied using ab initio quantum chemical calculations. Density functional theory (B3LYP) calculations using the 6-311++G(d,p) basis set consistently confirm that protonation of phenylphosphines takes place at the phosphorus atom; the C(4)-protonated phenylphosphine lying about 66 kJ mol(-1) above the P-protonated isomer. Similarly, methylation of phosphines consistently occurs at phosphorus. The proton and methyl cation affinities are estimated as follows: PA(phenylphosphine) = 863 +/- 10 kJ mol(-1) and MCA(phenylphosphine) = 515 -/+ 12 kJ mol(-1). Mono-halogen substitution appears to reduce the proton affinites by up to 20 kJ mol(-1). In this context, following P-protonation of either ameta- or a para-X-C(6)H(4)-PH(2), an elimination of the halogen X-atom under collisional activation (CA) conditions is expected to lead to a distonic radical cation, a low-energy isomer being 50 kJ mol(-1) above ionized phenylphosphine.

Journal Article↗

PubMedDate not supplied

[Effects of halogen derivative hydrocarbons on radiation damage of biological membranes].

Sharp increase of radiation-induced damages of isolated erythrocyte membrane lipids and proteins upon irradiation in presence of some halogen derivative hydrocarbon are shown. On chloroform and CCl4 examples it is shown that marked effects displayed under relatively low (submillimoles) concentrations and radiation doses that induced only insignificant oxidative membrane damages in absence of modifiers. The data are received which evidenced in favour of decisive role in these processes of halogenated organic radicals forming under one-electron reduction of halogen derivative hydrocarbons by hydrated electrons.

Carbon Tetrachloride↗

PubMed2000

Selective radiosensitization of drug-resistant MutS homologue-2 (MSH2) mismatch repair-deficient cells by halogenated thymidine (dThd) analogues: Msh2 mediates dThd analogue DNA levels and the differential cytotoxicity and cell cycle effects of the dThd analogues and 6-thioguanine.

Mismatch repair (MMR) deficiency, which underlies hereditary nonpolyposis colorectal cancer, has recently been linked to a number of sporadic human cancers as well. Deficiency in this repair process renders cells resistant to many clinically active chemotherapy agents. As a result, it is of relevance to find an agent that selectively targets MMR-deficient cells. We have recently shown that the halogenated thymidine (dThd) analogues iododeoxyuridine (IdUrd) and bromodeoxyuridine (BrdUrd) selectively target MutL homologue-1 (MLH1)-deficient human cancer cells for radiosensitization. The levels of IdUrd and BrdUrd in cellular DNA directly correlate with the ability of these analogues to increase the sensitivity of cells and tissues to ionizing radiation, and data from our laboratory have demonstrated that MLH1-mediated MMR status impacts dThd analogue DNA levels, and consequently, analogue-induced radiosensitization. Here, we have extended these studies and show that, both in human and murine cells, MutS homologue-2 (MSH2) is also involved in processing dThd analogues in DNA. Using both E1A-transformed Msh2+/+ and Msh2-/- murine embryonic stem (ES)-derived cells (throughout this report we use Msh2+/+ and Msh2-/- to refer to murine ES-derived cell lines that are wild type or mutant, respectively, for the murine Msh2 gene) and human endometrial cancer cells differing in MSH2 status, we see the classic cytotoxic response to 6-thioguanine (6-TG) in Msh2+/+ and human HEC59/2-4 (MSH2+) MMR-proficient cells, whereas Msh2-/- cells and human HEC59 (MSH2-/-) cells are tolerant (2-log difference) to this agent. In contrast, there is very little cytotoxicity in Msh2+/+ ES-derived and HEC59/2-4 cells to IdUrd, whereas Msh2-/- and HEC59 cells are more sensitive to IdUrd. High-performance liquid chromatography analysis of IdUrd and BrdUrd levels in DNA suggests that this differential cytotoxicity may be due to lower analogue levels in MSH2+ murine and human tumor cells. The DNA levels of IdUrd and BrdUrd continue to decrease over time in Msh2+/+ cells following incubation in drug-free medium, whereas they remain high in Msh2-/- cells. This trend was also found in MSH2-deficient human endometrial cancer cells (HEC59) when compared with HEC59/2-4 (hMsh2-corrected) cells. As a result of higher analogue levels in DNA, Msh2-/- cells are selectively targeted for radiosensitization by IdUrd. Fluorescence-activated cell-sorting analysis of Msh2+/+ and Msh2-/- cells shows that selective toxicity of the halogenated nucleotide analogues is not correlated with a G2-M cell cycle arrest and apoptosis, as is found for selective killing of Msh2+/+ cells by 6-TG. Together, these data demonstrate MSH2 involvement in the processing of IdUrd and BrdUrd in DNA, as well as the differential cytotoxicity and cell cycle effects of the halogenated dThd analogues compared with 6-TG. Therefore, IdUrd and BrdUrd may be used clinically to selectively target both MLH1- and MSH2-deficient, drug-resistant cells for radiosensitization.

Adenovirus E1A Proteins↗

PubMed2002

Depth of cure efficacy of high-power curing devices vs traditional halogen lamps.

PURPOSE: To determine the depth of cure resulting from three different curing devices in a photoactivated microhybrid composite through high-performance liquid chromatography (HPLC) analysis of leachable monomers. MATERIALS AND METHODS: Three different curing units, a halogen lamp (Heliolux, Vivadent), a xenon lamp (Kreative Kuring, Allyn Welch), and a plasma-arc lamp (Apollo 95, DMDS) were investigated using a universal microhybrid composite (P 60, 3M) as the test material. To assess the effect of curing device variation, a flexural strength test was performed. In addition, samples of composite were prepared and cured "in contact" (0 mm between the sample surface and light-guide tip) and through a specific thickness of composite (1, 2, or 3 mm). The monomers (bis-GMA and UDMA) eluted from the samples were detected by HPLC. RESULTS: No significant differences were found in the mechanical properties of composite cured with different light sources. In contrast, the concentration of eluted monomers (bis-GMA, UDMA) at a depth of 2 mm and more was significantly higher for the specimens cured with the high-power curing devices than those cured with the traditional halogen lamp. CONCLUSION: Under these experimental conditions, high-power curing devices were shown to be inferior in the deep polymerization of resin composite when compared to a traditional halogen lamp.

Analysis of Variance↗