Plasticizers in denture soft-lining materials: leaching and biodegradation

The leaching from soft lining materials into an aqueous buffer with the same esterase activity as that of saliva was compared to leaching into buffer without esterase activity. The buffer contained 0.1% non-ionic detergent, giving the medium a capacity to dissolve phthalates to the same degree as saliva. The hypothesis that esterase in the immersion medium will increase the rate of diffusion of plasticizers from denture soft-lining material was confirmed by the results. The average leaching of phthalates from 5.5 g of one of the materials was 4.5 mg kg(-1) d(-1) within the first 2 d and 1.1 mg kg(-1) d(-1) within the first 28 d. These levels may be compared to a LOAEL (lowest observed adverse effect level) of 52 mg kg(-1). It is concluded that an esterase activity, equivalent to that in saliva, in the immersion medium for soft lining materials increased the rate of diffusion of plasticizer from the materials. The measured levels of phthalates leaching from these materials might in vivo only be slightly less than 1/10 of the LOAEL given above.     

Leachability of plasticizer and residual monomer from commercial temporary restorative resins

OBJECTIVES: This study was performed to determine the compositions of commercial temporary restorative resins and to evaluate the leachability of plasticizer and residual monomer from them. METHODS: The chemicals in four commercial temporary restorative resins (Dura Seal, Fit Seal, Plast Seal Quick, and Poly Seal) were detected by GCMS and HPLC. The amounts of plasticizers and residual monomers that leached from cured resin samples immersed in ethanol for 1 h to 14 d were determined by HPLC. RESULTS: Phthalate esters used as plasticizers contained 40-55 wt% either di-n-butyl phthalate (DBP) or butyl phthalyl butyl glycolate. The resin monomer included methyl methacrylate (MMA) or a mixture of MMA and 2-hydroxyethyl methacrylate (HEMA); 1,3-butanediol dimethacrylate was added as a cross-linking agent. Each resin contained 40-60 wt% monomer. The amounts of phthalate esters leached increased with immersion time up to 7 d, reaching 120-190 microg/mg, and did not change subsequently. The residual monomers leached gradually for up to 3d and did not change subsequently. The amount of leached residual monomer (MMA, HEMA) was 20-90 microg/mg after 3d storage. More than 50% of the leachable plasticizers and monomers were eluted from the cured resins within 24 and 3 h, respectively. CONCLUSIONS: The amounts of leached plasticizers and residual monomers were extremely large compared with the concentrations of endocrine disrupters and their potentially genotoxic effects. Therefore, it is very important to evaluate the leachability of these compounds from temporary restorative resins.     

An in vivo and in vitro study of the loss of plasticizer from soft polymer-gel materials

Polymer-gel materials used as short-term denture soft linings are blended with plasticizers to lower the glass transition temperature (Tg). A lower Tg allows for greater polymer chain mobility, thus producing a more flexible material. The present work evaluated the loss of plasticizers due to leaching both in vivo and in vitro. Two commercial denture soft-lining materials (A and B) were tested. These were both poly(ethyl methacrylate) polymers, blended with alcohol and phthalate esters. A clinical study was conducted in which patients wore, sequentially, dentures bearing (on separate occasions) each of the two soft-polymer lining materials. The two materials A and B were randomly assigned for each of ten patients and were worn for 14 and 30 days, respectively. With one exception, patients wore dentures with both lining materials, for a total of 19 clinical evaluations. The plasticizer loss occurring during the clinical trial was determined by GC analysis from the initial and terminal day sampling of plasticizer content of the soft polymer-gel materials. The results of this analysis were compared with results obtained from an in vitro leachability study by use of sink conditions in water at 37 degrees C for the same two commercial soft polymers conducted over the same time periods of 14 and 30 days. The results indicated that a higher loss of plasticizer occurred in vivo, compared with the in vitro tests for 17 of the 19 clinical evaluations. The average plasticizer lost in vivo from material A at 14 days was 122 +/- 58 mg/g, and for material B at 30 days it was 33 +/- 27 mg/g.(ABSTRACT TRUNCATED AT 250 WORDS)     

The effects of six root-end filling materials and their leachable components on cell viability

This study investigated the effect of six root-end filling materials (Retroplast [Retroplast Trading, Dybes?vej, Denmark], Geristore, [DEN-MAT Corporation, Santa Maria, CA], Ketac Fil [3M ESPE, Seefeld, Germany], IRM [Caulk-Dentsply, Milford, DE], Super EBA [Bosworth Company, Skokie, IL], and MTA [Dentsply-Tulsa Dental, Johnson City, TN]) on the viability of Balb/C 3T3 fibroblasts using the [3-4, 5-dimethyl thiazol-2-yl]-2,5-diphenyl tetrazolium bromide succinate (MTT) assay. Ten discs (5 mm x 2 mm) of each material were eluted in tissue culture medium for 24 hours at 37 degrees C for 3 successive days and the elutes used for cell viability testing and for determination of leached components. The results showed that Retroplast, Geristore, and Ketac Fil increased cell proliferation, whereas Super-EBA decreased cell viability. The proliferative effect of Retroplast and Geristore increased with the eluting time (24 hours, 48 hours, and 72 hours), whereas the effects of the other materials did not significantly change. IRM and MTA did not affect cell viability. High-performance liquid chromatography analysis and atomic absorption spectroscopy showed that there was variation in the amount of leached components from the materials. Our results indicate that the reaction of cells to root-end filling materials varies considerably between materials.     

Effects of resin based dental composites on fertility of male mice

The purpose of this study was to investigate the effect of leached substances from dental composites on the fertility of male mice. Twenty adult male Swiss mice were divided into two groups of 10. Leached substances from composite specimens were administered, intragastrically, daily to the mice in the test group and distilled water to the control group for 28 d. Each mouse from both groups was mated with two untreated females. After mating, fertility of male mice in both groups was assessed. There was a significant reduction in the number of pregnancies in females mated with test males in comparison to those mated with control males (12/20 vs. 18/20, respectively). Females impregnated by test male mice showed a significant increase in the number of resorptions out of the total number of implantations (11% test vs. 1.5% control). The testicular sperm count and daily sperm production of the males in the test group was significantly reduced. Moreover, the relative weights of the testes and seminal vesicles were also significantly reduced in the test group. These results suggest that leached components from resin based dental composite materials have an adverse effect on the fertility and reproductive system of male mice.     

An investigation into bisphenol-A leaching from orthodontic materials

Objective:To quantitatively determine the bisphenol-A (BPA) leached from orthodontic materials during simulated intraoral exposure.Materials and Methods:Samples of orthodontic materials were subjected to simulated abrasion, immersion in artificial saliva, thermal shock via temperature cycling, and simulated intraoral exposure. Sample aliquots were collected for up to 2 weeks after artificial saliva immersion, derivatized, then analyzed for BPA by gas chromatography/mass spectroscopy.Results:Quantifiable amounts of leached BPA were observed from a thermoformed orthodontic retainer material (7.63 µg/g of material) and an orthodontic adhesive (2.75 µg/g of material). BPA leaching was only observed within the first 3 days of artificial saliva immersion.Conclusions:Under the test conditions, BPA was observed to leach from two orthodontic materials. While the quantities of leached BPA were below the reference dose for daily intake, existing data of low-dose effects and medical disorders associated with elevated urinary BPA levels suggest that BPA exposure, and thus the use of the leaching materials identified in this study, should be reduced or eliminated.     

Effect of curing method and storage condition on fluoride ion release from a fluoride-releasing resin cement

The purpose of this study was to evaluate fluoride ion release from a resin-modified glass ionomer cement (Fuji IILC improved, FLC) and a fluoridated resin cement (Panavia F, PF) following different curing methods and storage conditions. The specimens, which were either light-cured (LC) or chemical-cured (CC), were stored in either distilled water (DW) or demineralizing solution (DS; pH 4.5) for 1, 3, 7, 15, 30, 60, and 90 days. Fluoride ion release was measured using a fluoride ion-specific electrode. Data (n = 5) were statistically analyzed using one- and three-way ANOVA (p = 0.05). A "burst effect" was observed in the first week from both materials. However, fluoride ion release from FLC was seven times higher than that from PF. Storage in demineralizing solution accelerated the amount of fluoride release from both materials. In addition, LC yielded a lower amount of fluoride ion release from both materials, as compared to CC. It was concluded that both curing mode and storage medium influenced the amount of fluoride release from the tested materials.     

An in vitro study into the corrosion of intra-oral magnets in the presence of dental amalgam

The aim of this investigation was to study the corrosion behaviour and products of uncoated neodymium-iron-boron magnets in the presence of dental amalgam. Microcosm plaques were grown on discs of neodymium-iron-boron magnets or amalgam in a constant depth film fermentor. The biofilms were supplied with artificial saliva and growth was determined by viable counting. The results showed that the neodymium-iron-boron magnets corroded with an average daily weight loss of 0.115 +/- 0.032 per cent. However, when the magnets were in close proximity to the amalgam the amount of corrosion was reduced to a daily loss of 0.066 +/- 0.023 per cent. The highest loss of constituent elements from the corrosion products of the magnets was observed for iron. The composition of the microcosm plaques altered markedly between the two materials with less streptococci and more Veillonella spp. present in the biofilms grown on magnets in the presence of amalgam. The corrosion of neodymium-iron-boron magnets is limited and in the presence of amalgam is reduced further. This suggests that amalgam present in the mouth will not cause an increased clinical risk in terms of biocompatibility with neodymium-iron-boron magnets.     

Prevention of enamel demineralization adjacent to glass ionomer filling materials

Abstract – In order to study the release of fluoride and prevention of enamel demineralization by different filling materials, standardized cavities were prepared in 80 extracted human molars. The cavities were filled as follows: 1. Fuji II F; 2. Ketac-Fil; 3. Ketac-Silver; 4. Silar. Twenty molars were used as controls (no filling). Enamel slabs with the fillings were subjected to 9 days of demineralization (30 min daily) and remineralization (artificial saliva, replaced daily). Fluoride release in the saliva was determined on days 1, 3, 5, and 9. Enamel fluoride content adjacent to the cavities was determined initially and after the de-remineralization using the acid etch technique. On day 1, the largest amount of fluoride in the saliva was released by Fuji, but on day 9 the largest amount was released by Ketac-Fil. Ketac-Silver released significantly less fluoride than Fuji and Ketac-Fil. The average initial fluoride content of enamel was 2200 ppm. After the test period, fluoride contents adjusted for biopsy depth were 1822, 1690, 1693, 1337, and 888 ppm in groups 1-5, respectively. The amounts of phosphorus dissolved by the second acid etch were 28.9 (SE 2.6), 30.2 (2.0), 34.4 (2.8), 44.1 (2.7), and 42.2 (2.4) μg, respectively. Softening of surface enamel during the test period was clearly reduced in teeth filled with Fuji and Ketac-Fil. The results show that glass ionomer materials release considerable amounts of fluoride and prevent demineralization of the adjacent enamel in vitro. Fuji and Ketac-Fil seem to be more effective than Ketac-Silver.     

Prevention of enamel demineralization adjacent to glass ionomer filling materials

In order to study the release of fluoride and prevention of enamel demineralization by different filling materials, standardized cavities were prepared in 80 extracted human molars. The cavities were filled as follows: 1. Fuji II F; 2. Ketac-Fil; 3. Ketac-Silver; 4. Silar. Twenty molars were used as controls (no filling). Enamel slabs with the fillings were subjected to 9 days of demineralization (30 min daily) and remineralization (artificial saliva, replaced daily). Fluoride release in the saliva was determined on days 1, 3, 5, and 9. Enamel fluoride content adjacent to the cavities was determined initially and after the de-remineralization using the acid etch technique. On day 1, the largest amount of fluoride in the saliva was released by Fuji, but on day 9 the largest amount was released by Ketac-Fil. Ketac-Silver released significantly less fluoride than Fuji and Ketac-Fil. The average initial fluoride content of enamel was 2200 ppm. After the test period, fluoride contents adjusted for biopsy depth were 1822, 1690, 1693, 1337, and 888 ppm in groups 1-5, respectively. The amounts of phosphorus dissolved by the second acid etch were 28.9 (SE 2.6), 30.2 (2.0), 34.4 (2.8), 44.1 (2.7), and 42.2 (2.4) micrograms, respectively. Softening of surface enamel during the test period was clearly reduced in teeth filled with Fuji and Ketac-Fil. The results show that glass ionomer materials release considerable amounts of fluoride and prevent demineralization of the adjacent enamel in vitro. Fuji and Ketac-Fil seem to be more effective than Ketac-Silver.     

A clinical pilot study of the time-dependent composition of tooth bleaching systems

This pilot study was undertaken to determine the compositional changes in tooth bleaching materials as a function of time in vivo. Ten patients were recruited and two bleaching systems were used - one a paste and the other a gel. Each material was placed in a custom bleaching tray and worn by each patient for each of four times - 15, 30, 60 and 120 min. The material was collected and chemically analysed for water by Karl Fischer titration and titrated for carbamide peroxide by the US Pharmacopoeia method. The paste material contained 18.66% water as supplied, and after 2 h this rose to between 28.6 and 64.4%. The gel material contained 2.85% water as supplied, and after 2 h this was diluted to between 28.5 and 73.4%. There was considerable difference in saliva uptake by the custom tray between patients. Most water uptake usually occurred within the first 30 min. Peroxide concentrations decreased in an approximately linear manner with time. There was a significant difference between the materials from baseline to 30 min and thereafter (P < 0.0009). This pilot study is an effective technique for chemical evaluation of bleaching materials. The effect of saliva is an important factor to consider, and is one that has hitherto not always been appropriately emphasized.     

Fluoride intake by children at risk for the development of dental fluorosis: comparison of regular dentifrices and flavoured dentifrices for children

The aim of the present study was to determine fluoride intake by children at risk of dental fluorosis according to the type of dentifrice used. Forty-two volunteers aged between 20 and 30 months, from 2 kindergartens, were supervised while brushing their teeth with regular dentifrices (nominally 1,500 ppm F) and dentifrices flavoured for children (nominally 1,100 ppm F), brushing 3 times with each type in random order to minimize bias. The amount of fluoride ingested was determined by subtracting the weight of dentifrice recovered from the weight used and calculating the mean of the 3 brushings. Fluoride was analyzed with specific electrodes. Parents were asked how often the children brushed their teeth and the daily tooth brushing frequency was used to calculate the daily fluoride intake. The average fluoride intake using regular dentifrices and those flavoured for children was 0.567 +/- 0.300 and 0.630 +/- 0.320 mg F/day, respectively, corresponding to doses of 0.046 +/- 0.023 and 0.051 +/- 0.026 mg F/kg/day (p > 0.05). Fluoride intake was slightly higher with the use of dentifrices flavoured for children. Moreover, the dose to which children were exposed with either type of dentifrice was very close to that which is considered the limit (0.05-0.07 mg F/kg/day).     

The effects of training time,sensory loss and pain on human motor learning

Summary This study determined, in humans, the effects of (i) the number of within‐session task repetitions (72 or 144 over a period of 15 or 30 min, respectively) on the time course of motor learning in a long‐term (seven consecutive daily motor‐training sessions and a 1‐week post‐follow‐up) novel tongue‐task training regime and (ii) somatosensory manipulations (capsaicin‐induced intra‐oral pain or lidocaine‐induced sensory loss of the tongue tip) on motor learning in a short‐term (single motor‐training session consisting of 72 within‐session task repetitions over a period of 15 min) novel tongue‐task training regime. Novel tongue‐task training consisted of tracking a moving target box by generating a pre‐set amount of tongue‐protrusion force onto a force lever. Analysis of motor behaviour revealed (i) a higher within‐session gain for the 30‐min tongue‐task training regime, but this difference did not differentially affect the time course of the overall motor performance or additional motor performance variables between the 15‐ and 30‐min tongue‐task training regimes in subsequent training sessions. (ii) somatosensory manipulations of the tongue tip reduced the gains in overall motor performance, and this reduced motor performance was mainly characterized by exaggerated undershoot errors and delayed reaction times for the lidocaine tongue‐task training regime and exaggerated overshoot and undershoot errors as well as delayed reaction times for the capsaicin tongue‐task training regime. It is concluded that extended within‐session task repetitions do not facilitate additional long‐term gains in overall motor performance and intra‐oral sensory loss or pain hinders motor learning.     

The effect of intrasulcular toothbrushing on the amount of sulcular fluid.

Nineteen young adult Caucasian males had an average Gingival Score of 0.47. Each was asked to demonstrate his present method of toothbrushing. Thirteen used a scrub method, and six combined the scrub and roll methods. Sulcular fluid measurements were taken from the facial aspect of the mandibular left second bicuspid using filter paper strips stained with ninhydrin. An average value of 0.94 mm was obtained. Intrasulcular brushing was performed in the mandibular left posterior segment, for 30 seconds daily for 40 days. The brushing was done by the investigator on 28 days and by the subjects on 12 days. The average Gingival Index score following intrasulcular brushing was 0.26. Sulcular fluid measurements were again taken from the mandibular left second bicuspid. A decreased amount of sulcular fluid was found in six subjects, while nine exhibited an increase and four showed no change. An average sulcular fluid measurement of 0.87 mm resulted following the experimental brushing period. From these data, it can be concluded that, within the limitations of this study, intrasulcular brushing had no significant effect on the amount of gingival fluid.     

Tip-Edge plus技术和MBT技术矫治成人安氏Ⅱ~1类错的对比研究

目的观察并比较Tip-Edge plus差动直丝弓技术和MBT滑动直丝弓技术治疗成人安氏Ⅱ~1类错的效果。方法根据纳入标准选择安氏Ⅱ~1类错畸形患者40例,随机分成两组。试验组20例采用Tip-Edge plus矫治器,对照组20例采用MBT矫治器配合中等支抗进行治疗。治疗前后拍摄头颅侧位片并测量,进行成组和配对t检验。结果 (1)未使用额外支抗的试验组与使用中等支抗的对照组取得相似的软硬组织改变效果,两组上磨牙前移量无统计学差异,试验组矫治后下切牙唇倾度大于对照组。(2)试验组打开咬合平均需3.8个月,平均复诊次数为16次;对照组打开咬合平均6.3个月,平均复诊次数为22次,差异有统计学意义(P<0.05)。结论对于需要使用中度支抗的成人安氏Ⅱ1类错患者应用Tip-Edge plus技术和MBT滑动直丝弓技术矫正能取得相似的软硬组织改变效果、支抗效果,但Tip-Edge plus技术打开咬合时间短,能减少复诊次数。     

Comparative tooth whitening efficacy of 18% carbamide peroxide liquid whitening gel using three different regimens

OBJECTIVE: Recently, a novel paint-on liquid whitening gel--Colgate Simply White Clear Whitening Gel--which contains 18% carbamide peroxide, has been developed as a self-administered tooth bleaching system. The purpose of the present study was to determine the efficacy and safety of this product using alternate exaggerated or simplified treatment regimens. METHODOLOGY: This was a three-week clinical trial using a parallel, double-blind, stratified protocol with three different instructions for application: 1) twice-daily, no air-drying, and 15 minutes without eating/drinking; 2) three times daily, 30-second air-drying and 30 minutes without eating/drinking; or 3) four times daily, 30-second air-drying and 30 minutes without eating/drinking. One-hundred and twenty (120) healthy volunteers were balanced into three equal groups based on shade scores (A3 or darker). Clinical evaluations (shade guide, oral tissue health, gingival index and visual analog sensitivity score) were performed on each group at baseline and weekly for the next 21 days. At the conclusion of the study, a survey of the subjects' opinions on their assigned product regimen was also conducted. RESULTS: Subjects who used Colgate Simply White Clear Whitening Gel three and four times daily achieved the greatest shade improvement (5.88 +/- 1.53 shades, and 5.57 +/- 1.54, respectively). However, these values were only about one shade better than the value observed for the more convenient, twice-daily, "no-dry" regimen (4.51 +/- 1.77 shades), though they were statistically significant (p < 0.05). The result for the four-times daily protocol was not statistically different from the three-times group. Also, no differences were observed between the groups concerning oral tissue health, gingival index or tooth sensitivity, and no adverse effects were observed or reported regardless of the regimen used. Surveys completed by the subjects showed that those who used the twice-daily, "no-dry" regimen found the product to be the easiest to use, the most comfortable and the most pleasant tasting. CONCLUSION: It can be concluded from the clinical data that three or four applications of Colgate Simply White Clear Whitening Gel per day provided better efficacy. In addition, the use of the whitening gel twice daily, even without "dry time" and only 15 minutes without eating/drinking, yielded results that were comparable to previously reported results using the original on-label directions. The potential additional benefit to the "simplified regimen" is that it was perceived to be the most convenient and comfortable. The use of Colgate Simply White Clear Whitening Gel up to four times daily for up to three weeks is also safe, and the tendency of abusing the product with more frequent daily use may be deterred by the inconvenience reported by the study subjects.     

Cytotoxicity of substances leached or dissolved from pulp capping materials

AIM: To evaluate the cytotoxic effects of substances leached or dissolved from pulp capping materials on human pulp fibroblasts. METHODOLOGY: The substances were applied to cell cultures in conditioned media. The experimental groups were: GI (control; n = 24)--cultures treated with fresh medium; GII (n = 24)--cultures treated with calcium hydroxide cement; GIII (n = 24)--cultures treated with adhesive resin and GIV (n = 24)--cultures treated with 37% orthophosphoric acid. The media were conditioned by placing the crude materials in contact with fresh culture medium for 1 h. The cytotoxicity analysis was performed using the Trypan blue dye exclusion assay at times of 0, 6, 12 and 24 h for cell viability assay, and at 1, 3, 5 and 7 days for survival assay. Data were treated by anova (P < 0.05) and Tukey's test (P < 0.05). RESULTS: GI and II presented similar cell viability and cell growth. GIII and IV exhibited statistically significant lower percentages of cell viability: GIV only at the 0 h experimental time, whereas in GIII this viability markedly diminished reaching values of 10% by 12 h. Cell growth was impaired only in cultures of GIII. CONCLUSIONS: Substances dissolved from the adhesive system tested were cytotoxic for human dental pulp fibroblasts in culture, whilst substances leached from calcium hydroxide were biocompatible.     

The association of gingivitis and periodontitis with ischemic stroke

OBJECTIVES: The aim of this study was to assess the associations of different periodontal parameters with cerebral ischemia. METHODS: In a case-control study, 303 consecutive patients with ischemic stroke or transient ischemic attack, and 300 representative population controls received a complete clinical and radiographic dental examination. Patients were examined on average 3 days after ischemia. The individual mean clinical attachment loss measured at four sites per tooth was used as indicator variable for periodontitis. RESULTS: Patients had higher clinical attachment loss than population (p<0.001). After adjustment for age, gender, number of teeth, vascular risk factors and diseases, childhood and adult socioeconomic conditions and lifestyle factors, a mean clinical attachment loss >6 mm had a 7.4 times (95% confidence interval 1.55-15.3) a gingival index >1.2 a 18.3 times (5.84-57.26) and a radiographic bone loss a 3.6 times (1.58-8.28) higher risk of cerebral ischemia than subjects without periodontitis or gingivitis, respectively. CONCLUSION: Periodontitis is an independent risk factor for cerebral ischemia and acute exacerbation of inflammatory processes in the periodontium might be a trigger for the event of cerebral ischemia.     

Compressive strength and surface characterization of glass ionomer cements modified by particles of bioactive glass.

OBJECTIVES: The aim of this study was to determine compressive strength, Young's modulus of elasticity, and Vickers' surface hardness, of conventional cure and resin-modified glass ionomer cements after the addition of bioactive glass (BAG) particles into the cements. METHODS: Experimental glass ionomer cement (GIC)-BAG materials were made by mixing 10- or 30-wt% of BAG particles with conventional cure and resin-modified GIC powders. Materials were processed into cylindrical specimens and immersed in water for 1, 3, 7, 14, 30 and 180 days before mechanical tests. SEM and EDS analysis was used to characterize the changes in surface topography and the main elemental composition. RESULTS: The compressive strength of the test specimens decreased with the increasing amount of BAG. The compressive strength of resin-modified GIC increased during the immersion, but remained at a lower level than that of the other materials. The conventional cure GIC-based materials had on average 55% higher surface microhardness than the resin-modified materials. In the elemental composition, more Ca was detected in the BAG-containing materials than in the pure GICs. The amount of F was significantly higher (p < 0.001) on all resin-modified materials, being highest on resin-modified GIC with 30-wt% of BAG after 180d of immersion. SIGNIFICANCE: The addition of BAG to GIC compromises the mechanical properties of the materials to some extent. Thus, their clinical use ought to be restricted to applications where their bioactivity can be beneficial, such as root surface fillings and liners in dentistry, and where high compressive strength is not necessarily needed.     

Long-term release of monomers from modern dental-composite materials

The elution of monomers from composite materials influences the biocompatibility of dental restorations. The purpose of the present study was to investigate the elution of monomers [bisphenol A glycidyl methacrylate (BisGMA), triethylene glycol dimethacrylate (TEGDMA), urethane dimethacrylate (UDMA), and bisphenol A (BPA)] from two light-cured materials (nanohybrid and ormocer) and from a chemically cured composite material, after different curing times (0, 20, 40 and 80 s) and different storage periods (24 h, 7 d, 28 d, and 1 yr after curing). Each specimen was stored in 1 ml of 75% ethanol. This medium was renewed after 24 h, 7 d, 28 d, and 1 yr. The ethanol samples were analyzed using liquid chromatography tandem mass spectrometry (LC–MS/MS). The amount of monomers released from the nanohybrid and the chemically cured composite was significantly higher than released from the ormocer. The curing time exerted a significant effect on the release of monomers. For the nanohybrid, less monomer was released after increasing the curing time. For the ormocer, 80 s of curing resulted in a higher degree of monomer release. The effect of storage differed between the monomers. Although the elution of TEGDMA was significantly decreased after storage for 28 d and 1 yr, a similar amount of BisGMA was released at each storage time-point analyzed, even after 1 yr. The present study showed that ormocer released a very small amount of monomers compared with the other materials.