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PubMed1994

The reactivity of selected acrylate esters toward glutathione and deoxyribonucleosides in vitro: structure-activity relationships.

Acrylate esters are alpha,beta-unsaturated esters used as plastic monomers whose toxicity may involve reaction with tissue nucleophiles via Michael addition. Structure-activity relationships for reactivity of selected esters with glutathione (GSH) and deoxyribonucleosides were investigated in the present studies. The esters investigated were methyl acrylate, methyl methacrylate, ethyl acrylate, ethyl methacrylate, butyl acrylate, butyl methacrylate, tetraethyleneglycol diacrylate, tetraethyleneglycol dimethacrylate, and ethyleneglycol dimethacrylate. To compare their reactivities toward GSH, esters were incubated for up to 1 hr at 37 degrees C and pH 7.4 with either GSH or red blood cells in phosphate-buffered saline followed by measurement of free thiol. In both systems acrylate electrophilic reactivity decreased with alpha-methyl substitution; however, the decrease in electrophilic reactivity was more evident in the cell-free system than in the red blood cell model. Increased alcohol chain length moderately affected the apparent second-order rate constant for the spontaneous reaction of acrylate esters with GSH, but did not affect potency relative to cellular GSH depletion. The apparent second-order rate constants of bifunctional esters are more than twice the rate constants of the much smaller monofunctional esters. Ethyl acrylate, a reactive acrylate ester based upon glutathione alkylation, has been designated a class 2B (suspect human) carcinogen by the International Agency for Research on Cancer. To detect possible DNA alkylation by acrylate esters in vitro, ethyl acrylate was incubated with deoxyribonucleosides for up to 24 hr at pH 6.7 or 7.4 and 37 degrees C or up to 8 hr and 50 degrees C. HPLC analysis revealed no detectable adduct formation.(ABSTRACT TRUNCATED AT 250 WORDS)

Acrylates↗
PubMed2006

Posterior capsule opacification after implantation of a hydrophilic or a hydrophobic acrylic intraocular lens: one-year follow-up.

PURPOSE: To evaluate the effect of hydrophilic and hydrophobic single-piece acrylic intraocular lenses (IOLs) on posterior capsule opacification (PCO) after cataract surgery. SETTING: St. Erik's Eye Hospital, Stockholm, Sweden. METHODS: In a prospective study, 120 patients having cataract surgery were randomized to implantation of a hydrophilic acrylic IOL (BL27, Bausch & Lomb) or a hydrophobic acrylic IOL (AcrySof SA60AT, Alcon). Surgery was performed according to a standardized protocol by 1 of 3 surgeons. Best corrected visual acuity, contrast sensitivity, glare, intraocular pressure, and flare were measured 1 week, 3 months, and 1 year after surgery. Posterior capsule opacification was assessed by digital retroillumination photography and analysis using POCOman software at 1 year. The rate of neodymium:YAG (Nd:YAG) capsulotomy for each IOL was also recorded. RESULTS: At 1 year, the hydrophilic acrylic IOL group had a significantly greater percentage area and severity of PCO than the hydrophobic acrylic IOL group (P<.001). Two patients in the hydrophilic acrylic IOL group and 4 in the hydrophobic acrylic IOL group had an Nd:YAG capsulotomy within the first year (P>.05). Contrast sensitivity was significantly better in the hydrophilic acrylic group at 3 months (P<.05); however, at 12 months no difference between the IOLs was observed. There was no significant difference in the other measured parameters. CONCLUSION: Patients with the hydrophilic acrylic BL27 IOL had a significantly greater percentage area and severity of PCO than those with the hydrophobic acrylic SA60AT IOL 1 year after surgery.

Acrylic Resins↗
PubMed2005

Effects of polishing techniques on the surface roughness of acrylic denture base resins.

STATEMENT OF PROBLEM: Rough surfaces of denture bases promote adhesion of microorganisms and plaque formation. It is therefore important to know how different polishing systems affect surface roughness of denture base acrylic resins. PURPOSE: The objective of this study was to compare the effects of 4 chairside polishing kits and 2 conventional laboratory techniques used for polishing 3 different acrylic denture base resins. MATERIAL AND METHODS: Using contact profilometric measurement, the surface texture of 54 specimens (15x30x3 mm) per acrylic material (autopolymerized ProBase Cold, heat-polymerized ProBase Hot, and injection heat-polymerized SR Ivocap plus) was studied before and after cutting with a tungsten carbide bur, and during and after chairside polishing with 4 polishing kits (Exa Technique, Acrylic Polisher HP blue, AcryPoint, Becht Polishing Cream), and after conventional polishing with 2 polishing systems (Universal Polishing Paste for Resins and Metals, Lesk Polishing Liquid). There were 9 specimens for each acrylic resin material and polishing method combination. Conventional lathe polishing with polishing paste served as the control. Mean average surface roughness (Ra) values of each specimen group were analyzed using a 2-way analysis of variance, the Scheffé post-hoc test, and paired t test (alpha=.05) with the Bonferroni adjustment. After testing the polished acrylic resin surfaces were evaluated under a scanning electron microscope. RESULTS: The highest mean average surface roughness (Ra=2.86+/-0.8 microm to 3.99+/-1.31 microm) was measured for surfaces finished with a tungsten carbide bur. The lowest surface roughness values (Ra=0.02+/-0.01 microm) were determined for acrylic resin specimens polished with a lathe and polishing paste. The Ra values of resin specimens after polishing with chairside silicone polishing kits ranged from 0.05+/-0.0 microm to 0.35+/-0.05 microm. Mean average Ra values of specimens polished with a polishing cream alone (Ra=1.01+/-0.17 microm to 1.68+/-0.47 microm) were significantly higher (P<.05) than those obtained with other polishing systems tested, which was confirmed by scanning electron microscope images of acrylic resin surfaces. Significant differences in mean average surface roughness were found between autopolymerizing and injected heat-polymerizing resin specimens. In addition, scanning electron microscopy revealed increased porosity of autopolymerizing resin specimens. CONCLUSIONS: Conventional laboratory polishing was found to produce the smoothest surface of denture base acrylic resin. Chairside silicone polishing kits produced a significantly smoother surface of acrylic resin than specimens polished with a tungsten carbide bur. The presence of large pores was characteristic for the autopolymerizing resin material.

Acrylic Resins↗
PubMed2001

The effects of surface roughness and type of denture acrylic on biofilm formation by Streptococcus oralis in a constant depth film fermentor.

AIMS: To investigate the effects of surface roughness and type of denture acrylic on the early development of a Streptococcus oralis biofilm in a constant depth film fermentor (CDFF). METHODS AND RESULTS: Streptococcus oralis was incubated with acrylic of known surface roughness in the CDFF. Adherent Strep. oralis were enumerated by viable counting. Cold-cure acrylic was rougher (P < 0.01) than heat-cure acrylic after polishing with abrasive paper of any given grit-grade. Heat-cure acrylic was colonized by fewer (P < 0.001) bacteria than cold-cure acrylic at any given surface roughness. The number of bacteria adhering to heat-cure and cold-cure acrylic increased linearly with mean surface roughness after 2 h incubation, the increase being greater (P < 0.001) for the cold-cure compared with the heat-cure acrylic. However, after 4 h incubation, surface roughness appeared to have no effect on the number of adherent bacteria. CONCLUSION: The type of acrylic used, and its roughness, affect the early stages of biofilm formation by Strep. oralis. SIGNIFICANCE AND IMPACT OF THE STUDY: Choosing an appropriate type of smooth acrylic could lead to reduced biofilm formation in vivo.

Biofilms↗
PubMed1997

10 years of patch testing with the (meth)acrylate series.

Statistics on 10 years of patch testing with 30 (meth)acrylates were compiled. Altogether 275 patients were patch tested and 48 patients (17.5%) had an allergic reaction to at least 1 (meth)acrylate. The (meth)acrylates most often provoking an allergic patch test reaction were 2-hydroxyethyl acrylate (2-HEA; 12.1%), 2-hydroxypropyl methacrylate (2-HPMA; 12.0%) and 2-hydroxyethyl methacrylate (2-HEMA; 11.4%). No allergic reactions were caused by 2-ethylhexyl acrylate (2-EHA), 2,2-bis[4-(methacryloxy)phenyl]propane (BIS-MA), trimethylolpropane triacrylate (TMPTA), oligotriacrylate 480 (OTA 480), N,N-methylenebisacrylamide (MBAA), or ethyl cyanoacrylate (ECA). The frequency of allergic patch test reactions presented cannot be considered as a "ranking" list of the most sensitizing (meth)acrylate compounds. In order to be able to judge the sensitization capacity of various (meth)acrylate compounds in humans, it would be necessary to have detailed information on the exposure history of the patients studied, including the purity of the (meth)acrylate compounds. Currently, this is not possible because (meth)acrylate-containing products regularly contain undeclared (meth)acrylate compounds.

Allergens↗
PubMedDate not supplied

In vitro measurement of bone-acrylic interface pressure during femoral component insertion.

Bone-acrylic interface pressure measurements were recorded at the medial interior rasped surfaces of fresh cadaver femurs during digital packing of acrylic bone cement and during insertion and seating of a Trapezoidal-28 femoral total hip component. Plugging of the femoral canal below the tip of the prosthesis stem was an effective means for increasing pressure in the distal femoral canal when the stem was inserted in the early stages of acrylic polymerization (i.e. immediately after dough time). At surgery, this can be accomplished by inserting a small bolus of acrylic down the canal to a depth below the tip of the seated stem and allowing it to polymerize in place. This forms an effective seal which prevents distal extrusion of the acrylic when the cavity is then packed prior to prosthesis insertion. Elimination of cement in the distal canal also avoids any future difficulty of acrylic removal should revision become necessary due to loosening or infection. No significant pressure differences were observed between one and two millimeter thicknesses of acrylic between the metal and bone. Interface pressures developed during finger packing were of the same order of magnitude as those achieved during seating of the femoral component. Use of a rubber diaphragm stretched tightly over the margins of the rasped femoral cavity helped to contain the acrylic and prevent extrusion during finger packing but was ineffective in increasing interface pressure. When this method is used, the acrylic can be poured or injected into the canal and packed before dough stage and thus facilitate increased cancellous penetration when the acrylic is in a state of low viscosity.

Arthroplasty↗
PubMed1985

Ethyl acrylate-induced gastric toxicity. II. Structure-toxicity relationships and mechanism.

Earlier studies conducted in this laboratory demonstrated that gavage administration of ethyl acrylate caused pronounced gastric toxicity in rats given single or repeated doses. The current studies were undertaken to investigate the structural, metabolic, and physical basis of this chemically induced gastric toxicity. Gavage administration of equimolar doses (2 mmol/kg) of methyl or ethyl acrylate in corn oil resulted in profound gastric toxicity in male F344 rats, while acrylic acid and n-butyl acrylate were without effect. Furthermore, gavage administration of equimolar doses of methyl propionate or ethyl propionate (saturated analogues of methyl acrylate and ethyl acrylate, respectively) as well as methacrylic acid esters were without gastric toxicity. These results indicate that structural requirements for acrylate esters to cause gastric lesions include an intact ester moiety, a double bond, and no substitution at carbon number 2. Additional studies indicate that gastric toxicity may be attributed to the intact ester molecule or to metabolite(s) other than products of carboxylesterase-mediated hydrolysis (acrylic acid and alcohol) and that gastric toxicity is dependent upon both acrylate ester concentration in dose vehicle and the lipophilicity of the dose vehicle (corn oil vs water).

Acrylates↗
PubMed1992

Rates of ethyl acrylate binding to glutathione and protein.

Ethyl acrylate is a monomer used extensively in polymer manufacturing. Although ethyl acrylate is toxic at high concentrations, it is metabolized and detoxified rapidly at low concentrations. In the current studies, in vitro experiments have demonstrated that [14C]ethyl acrylate reacts with both glutathione (GSH) and protein to give either [14C]3-(glutathion-S-yl)ethylpropionate or covalently bound protein adducts, respectively. The second-order rate constant for [14C]ethyl acrylate conjugation with GSH was determined by quantification of [14C]3-(glutathion-S-yl)ethylpropionate using an HPLC system equipped with a flow-through radioactive detector. The rate constant for conjugation was 32.8 M-1 min-1. Additionally, the apparent second-order rate constants were determined for [14C]ethyl acrylate binding to the protein fraction of 14 whole tissue homogenates. Estimation of total protein binding sites was performed by reacting tissue homogenates with high concentrations of [14C]ethyl acrylate, while rates of binding were determined by reacting tissue homogenates with 200 microM [14C]ethyl acrylate at 37 degrees C for various periods of time. Apparent second-order rate constants for ethyl acrylate binding to protein homogenates were similar to that observed for GSH reacting with ethyl acrylate. The role of GSH-transferase in catalyzing 3-(glutathion-S-yl)ethylpropionate formation also was evaluated with whole tissue homogenates. In most tissues, the GSH-transferases poorly catalyzed the conjugation reaction. However, a significant increase in 3-(glutathion-S-yl)ethylpropionate formation was observed with liver homogenate.

Acrylates↗
PubMed2001

Changes in posterior capsule opacification after poly(methyl methacrylate), silicone, and acrylic intraocular lens implantation.

PURPOSE: To prospectively evaluate the progression of posterior capsule opacification (PCO) after poly(methyl methacrylate) (PMMA), silicone, and acrylic intraocular lens (IOL) implantation. SETTING: Hayashi Eye Hospital, Fukuoka, Japan. METHODS: Three hundred eyes of 300 patients scheduled to have IOL implantation were initially randomized into 3 groups based on IOL type: PMMA, silicone, or acrylic. Of the 300 eyes, 269 completed the follow-up. The PCO density in these eyes was measured 1 week and 3, 6, 12, 18, and 24 months postoperatively using special computer software developed for the Scheimpflug videophotography system. Visual acuity and the incidence of neodymium:YAG (Nd:YAG) laser capsulotomy were also examined. RESULTS: Three months postoperatively and later, the mean PCO value in the PMMA group increased significantly (P <.0001); the increase in the silicone and acrylic groups was not significant. The PCO value in the PMMA group was significantly greater than in the silicone or acrylic group (P <.0001). The PCO value in the acrylic group was slightly less than in the silicone group at 18 and 24 months, but the difference was marginal. The survival rate not requiring Nd:YAG capsulotomy was least in the PMMA group, followed by the silicone and acrylic groups in that order (P <.0001). The mean logMAR visual acuity in the PMMA group increased postoperatively and was worse than in the silicone or acrylic group. CONCLUSIONS: The degree of PCO after PMMA IOL implantation progressed significantly with time, while the progression after silicone and acrylic IOL implantation was slight. Therefore, PCO in eyes with a PMMA IOL was significantly more extensive than in those with a silicone or acrylic IOL and resulted in marked impairment of visual acuity.

Acrylic Resins↗
PubMed2004

Antimicrobial activity of p-hydroxyphenyl acrylate derivatives.

To estimate the antimicrobial effect of p-hydroxyphenyl acrylate (H5) derivatives on the basis of their molecular structure, the hydroxy and acryl groups of p-hydroxyphenyl acrylate were modified. The antimicrobial activity of the resulting compounds was assessed against a Gram-positive bacterium (Staphylococcus aureus), a Gram-negative bacterium (Pseudomonas aeruginosa), and fungi (Aspergillus fumigatus and Penicillium pinphilum) by the halo zone and the shake flask test. The antimicrobial activity of H5 was ascribed mainly to the acryl group. Compounds with acryl or acryloxy groups bound to the phenyl moiety were found to exhibit particularly high antimicrobial activities. The activities of phenyl acrylate and phenyl vinyl ketone were excellent as compared to aliphatic acrylates such as cyclohexyl acrylate and hexyl acrylate, indicating that the stereoelectronic effect of the phenyl group was important to the antimicrobial activity.

Acrylates↗
PubMed1998

Occupational respiratory hypersensitivity caused by preparations containing acrylates in dental personnel.

BACKGROUND: Allergic contact dermatitis caused by acrylate compounds is common in dental personnel; they also often complain of work-related respiratory or conjunctival symptoms. OBJECTIVE: The aim of the present study was to report the cases of acrylates induced respiratory hypersensitivity in dental personnel diagnosed in Finland during the last 6 years. METHODS: Occupational asthma, rhinitis, laryngitis and pharyngitis cases were diagnosed according to patient history, PEF monitoring, and a work-simulating provocation test. RESULTS: Twelve cases of respiratory hypersensitivity caused by acrylates diagnosed in dental personnel (six dentists and six dental nurses) in 1992-97 are reported. During this period one case of conjunctivitis and one of laryngitis have been published separately. Nine cases of occupational asthma, two rhinitis cases, and one laryngitis case were verified according to the challenge tests with dental acrylate compounds (acrylates, methacrylates and epoxy acrylates). Only three patients had positive skin-prick test reactions to common environmental allergens, and none reacted to acrylates in the skin-prick tests. Five patients had an elevated total IgE (>110 kU/L). PEF follow-up showed an occupational effect in all examined eight patients with diagnosed asthma. The mean duration of exposure to acrylates was 22 years, and the duration of respiratory symptoms 8 years. CONCLUSIONS: The results indicate that acrylates constitute an important hazard for dental workers. The mechanism of respiratory hypersensitivity is still unknown, and it is probably not IgE-mediated.

Acrylates↗
PubMed1980

An air sampling and analysis method for monitoring personal exposure to vapors of acrylate monomers.

A method for air sampling and analysis has been developed for vapors of acrylate monomers. Concentrations as low as 0.05 parts per million by volume (ppmv) can be measured, with the exception of 2-ethylhexyl acrylate which can be measured as low as 0.01 ppmv. These limits of sensitivity are based on a 60-minute sample at a flowrate of 500 cc per minute. The acrylate monomer vapor is adsorbed on activated silica gel, desorbed in acetone, and analyzed by gas chromatography using FFAP or OV-17 liquid phase columns. Three statistical studies show that this method is well within the accuracy and precision limits OSHA requires for methods of monitoring personnel exposure to air contaminants. Other parameters investigated were the effects of humidity, flowrate, and adsorption capacity, plus storage effects. This method has been applied to the following acrylate monomers; 2-ethylhexyl acrylate (2-EHA), hydroxyethyl acrylate (HEA), isodecyl acrylate (IDA), methylcarbamoyloxyethyl acrylate (MCEA), 2-henoxyethyl acrylate (PEA), esterdiol-204-diacrylate (ED-204-DA), and esterdiol-204-4-ethoxy-diacrylate (ED-204-4EO-DA).

Acrylates↗
PubMed2005

The effect of water absorption on acrylic surface properties.

PURPOSE: The aim of the present study was to determine whether an increased water content during thermal cycling of hot water-treated acrylic was associated with a reduction in surface hardness and an increased opacity or whitening of the surface. MATERIALS AND METHODS: Ten acrylic samples were treated with 30 soak cycles (cycle duration, 24 hours), using warm water (40 degrees C) and an alkaline peroxide tablet (Efferdent control group); a further ten samples were treated with boiling water (100 degrees C) and one Efferdent tablet (experimental group). Indentation hardness of the acrylic specimens was measured prior to and immediately following the completion of the warm and hot water treatments, using an automated micro-indentation system. The hydrated acrylic specimens were then allowed to air dry at room temperature (20 degrees C) and were weighed weekly until they had obtained a constant dry weight. The loss in weight of the acrylic specimens represented the maximum water absorption. RESULTS: The hot water-treated specimens were much whiter than the warm water-treated specimens. The mean reduction in hardness (H(IT)) of the acrylic specimens following the treatment with hot water and alkaline peroxide tablet was 12.9%. Treatment with warm water and alkaline peroxide resulted in a slight increase in mean hardness (2.63%). There was a significant correlation between the water content of the acrylic specimens after treatment and the percentage of change in indentation hardness (r= 0.495, p= 0.026). CONCLUSIONS: The hot water treatment of the acrylic was associated with a significant reduction in hardness. We attribute the whitening and reduction in the hardness of the hot water-treated specimens to absorption of water and a disruption of the acrylic surface structure.

Absorption↗
PubMedDate not supplied

Surface roughness of denture base acrylic resins after processing and after polishing.

PURPOSE: Circumstances exist in which the need to adjust denture base acrylic resins is necessary. This process obviously alters the surface of the polished denture base. The purpose of this study was to compare the effects of three chairside polishing kits and conventional polishing on four denture acrylic resins. MATERIALS AND METHODS: Twenty-four 30 x 30 x 2 mm acrylic resin specimens were fabricated with each of four acrylic resins: autopolymerizing, heat processed, injection molded, and microwaveable. One side was polished conventionally with pumice and polishing compound. The other side was polished with one of three chairside polishing kits: Axis, Brasseler, and Shofu. Each side was evaluated by a Dektak 8 Programmable Stylus Profiler to determine the surface roughness (Ra). RESULTS: One-way analysis of variance (ANOVA) revealed that: (1) There was no significant difference in the time it took to polish the specimens with the chairside polishing kits (F=2.118, p=0.14). (2) There was a significant difference in surface roughness between the acrylic resins before any polishing, with the injection-molded and heat-processed being less rough than the autopolymerizing (F=4.588, p=0.005). (3) There was a significant difference in surface roughness between the acrylic resins when conventionally polished, with the injection-molded and microwavable being less rough than the autopolymerizing (F=4.503, p=0.005). Factorial ANOVA revealed that: (1) There was no significant difference in the surface roughness among the chairside polishing kits (F=1.209, p=0.30). (2) There was a significant difference between the acrylic resins, with the heat-processed, injection-molded, and microwaveable being significantly less rough than the autopolymerizing (F=6.610, p=0.0001). (3) There was no significant interaction between the acrylic resins and the chairside polishing kit in the amount of surface roughness (F=1.728, p=0.12). An independent t-test revealed that conventional polishing was significantly smoother than polishing with the chairside polishing kits (t=3.847, p=0.0001). CONCLUSIONS: It was concluded that time was not a factor in using any of the chairside polishing kits. It is recommended that conventional polishing be used after adjustments to the cameo surface of denture acrylic resin.

Acrylic Resins↗
PubMed1993

Prevalence and sources of occupational contact sensitization to acrylates in Italy.

Acrylate-based products are widely utilized in the industrialized world and in the domestic environment. The aim of this study was to evaluate the prevalence and sources of occupational contact sensitization to acrylates in a selected population. Between January 1987 and April 1992, 82 patients suspected of occupational acrylic sensitization were patch tested with the GIRDCA standard series and an extensive acrylate series. Over this 5-year period, we detected sensitization to acrylates in 13.4% of cases. Dental materials and anaerobic sealants were the most important sources of acrylate sensitization. Among acrylic monomers, ethylene glycol dimethacrylate was the most frequent contact sensitizer in our study. Acrylate additives were also important sources of contact dermatitis in our patients. Although the clinical picture of airborne contact dermatitis due to acrylates has rarely been reported in the literature, it was commonly observed in our patients.

Acrylates↗
PubMed2004

Primary IOL implantation in children: a risk analysis of foldable acrylic v PMMA lenses.

BACKGROUND: /aims: To compare the relative risks of poly (methylmethacrylate) (PMMA) and soft acrylic (AcrySof) primary intraocular lens (IOL) implantation in paediatric cataract surgery. METHODS: A retrospective analysis of clinical data was performed on eyes of 61 infants and children who underwent cataract surgery with primary IOL implantation. Age at operation ranged from 3 weeks to 15 years. Mean follow up duration was 24.5 months (range 0.5-68 months). Factors examined included type of IOL (PMMA, acrylic), performance of a primary posterior continuous curvilinear capsulorhexis (PCCC) or capsulotomy with limited anterior vitrectomy, perioperative complications, and subsequent intervention for posterior capsule opacification (PCO). Risk factors for perioperative complications were examined with 2x2 tables to give odds ratios (OR) as measures of association. A survival analysis was performed to assess risk of subsequent intervention for PCO with different IOL types. Relative risks (hazards) and confidence intervals (CI) were calculated with Cox regression to adjust for potential confounding. RESULTS: Compared to acrylic, PMMA IOLs were significantly associated with perioperative complications (OR 5.2, 95% CI 1.4 to 19, p = 0.01). However, IOL and type of section were highly correlated factors, and this finding may reflect risks associated with larger scleral wounds used for PMMA IOLs. No statistically significant difference in risk of subsequent intervention for PCO was found between different IOL types. Mean times till intervention for PMMA and acrylic IOLs were 30.1 months (95% CI 22 to 38) and 19.8 months (95% CI 12 to 27) respectively (log rank test statistic 1.53, one degree of freedom, p = 0.22). At 12 months post-implant surgery, 76% (95% CI 59 to 93) of PMMA cases and 54% (95% CI 35 to 72) of acrylic cases had not required intervention for PCO; these proportions fell to 55% (95% CI 35 to 75) and 38% (95% CI 14 to 61) for PMMA and acrylic cases respectively at 2 years post-surgery. After adjustment for age at surgery, primary posterior capsulorhexis, and perioperative complications relative risk of intervention after acrylic IOL implantation was 1.6 (95% CI 0.66 to 3.9, p = 0.29). CONCLUSION: Primary implantation of foldable soft acrylic IOLs in paediatric eyes may allow fewer perioperative complications than rigid PMMA IOLs. Short term safety profiles of primary implantation in paediatric cataract surgery are otherwise comparable for PMMA and soft acrylic IOLs.

Acrylic Resins↗
PubMed1976

Pharmacological studies of N,N-dimethylaminoethyl chloroacetate and N,N-dimethylaminoethyl acrylate as inhibitors of choline acetyltransferase in isolated skeletal and smooth muscle preparations.

Two tertiary amine esters, N,N-dimethylaminoethyl chloroacetate (Cl-DMA) and N,N-dimethylaminoethyl acrylate (acryl-DMA), which have recently been shown to be inhibitors of choline acetyltransferase (ChAc) were investigated to determine their actions in isolated skeletal and smooth muscle preparations. Both compounds caused neuromuscular blockade in indirectly stimulated nerve-muscle preparations (ED50 values of Cl-DMA were 6.9 -42.0 X 10(-4) M and those of acryl-DMA were 1.2-5.8 X 10(-4) M). The blockade was completely or partially reversible after drug washout. A comparison of the ED50 values for neuromuscular blockade with the ID50 values for ChAc inhibition suggested that the acryl-DMA compound might not cause neuromuscular blockade via ChAc inhibition because the potency ratios (ED50/ID50) of Cl-DMA were higher than 1, whereas those of acryl-DMA were equal to or lower than 1. This was borne out by further experiments on isolated neuromuscular preparations which showed that the site of action for acryl-DMA was post-junctional, whereas that for Cl-DMA was prejunctional. In addition, the weak stimulating properties of Cl-DMA and acryl-DMA were investigated in isolated skeletal and smooth muscle. Cl-DMA was shown to be a partial cholinergic agonist, whereas acryl-DMA was a nonspecific stimulant not involving cholinergic receptors. Although both Cl-DMA and acryl-DMA are inhibitors of ChAc, only Cl-DMA appears to have sufficient specificity for use as a possible ChAc inhibitor in vivo.

Acetates↗
PubMed2005

Comparison of PMMA, foldable silicone and foldable acrylic hydrophobic intraocular lenses in combined phacoemulsification and trabeculectomy.

PURPOSE: To compare the postoperative results of phacotrabeculectomy with implantation of PMMA, foldable silicone or foldable hydrofobic acrylic intraocular lens (IOL). SETTING: Glaucoma unit, The Royal Liverpool University Hospital, Liverpool, United Kingdom. METHODS: We studied a total of 124 eyes of three consecutive groups of patients with glaucoma and cataract that underwent phacotrabeculectomy with implantation of a PMMA (30 eyes), a foldable silicone (57 eyes) or a foldable acrylic (37 eyes) IOL. Postoperative Snellen visual acuity and intraocular pressure (IOP), and early and late complications were assessed. All data were analyzed by means of chi2 test, Fisher's exact test, ANOVA/MANOVA tests or a combination whenever appropriate. RESULTS: In all three groups the early and late mean postoperative IOPs were significantly lower than the preoperative ones (p<0.001), with no intergroup differences (p=0.48). The number of eyes with early postoperative hypertension (IOP>25 mmHg) and hypotony (IOP<7 mmHg) was similar in the three groups (p=0.91 and p=0.92 respectively). All groups showed improvement in mean visual acuity (p<0.001), and the differences among the groups were not significant (p=0.79). By 9-12 months after surgery IOPs lower than 22 mmHg without glaucoma medication were found in 76.9% in the PMMA group, 76.6% in the silicone group and in 76.9% in the acrylic group. At the same interval, best visual acuity of 6/12 or better was attained in 80.8%, 83% and 80.8%, in the PMMA, silicone and acrylic groups respectively. The silicone group had significantly more postoperative fibrin reaction into the anterior chamber (p=0.01) and giant cell deposits on the IOL (p<0.0001) than the PMMA and the acrylic groups. The rate of Yag laser posterior capsulotomy was lower with the acrylic IOL (0%) than with the silicone (12.2%) or PMMA (13.3%) IOLs (p=0.08). CONCLUSION: In patients with glaucoma and cataract, phacotrabeculectomy with PMMA, silicone or acrylic IOL was equally effective in lowering the IOP and improving visual acuity. However, incidence of fibrin reaction and lens deposits was higher in those eyes which received a silicone IOL. The PMMA and the acrylic groups did not differ with respect to postoperative complications, but those eyes with an acrylic IOL had a lower rate of posterior capsule opacification.

Acrylic Resins↗