Ketac Molar Easymix Research Articles

Titanium dioxide nanotubes incorporated into conventional glass ionomer cement alter the biological behavior of pre-odontoblastic cells

The objective was to address the repercussion of adding titanium dioxide nanotubes (TiO2-nt) into high-viscosity conventional glass ionomer cement (GIC) on the biological properties of pre-odontoblastic cells (MDPC-23) challenged by lipopolysaccharides (LPS - 2 μg/mL). TiO2-nt was added to Ketac Molar EasyMix at 3, 5, 7 %, whereas unblended GIC served as control. Analyses included proliferation (n=6; 24, 48, 72 h), metabolism (MTT; n=6; 24, 48, 72 h); morphology laser microscopy (n=3; 24, 48, 72 h); proteome assessments IL-1β, IL-6, IL-10, VEGF, TNF-α (n=3; 12, 18 h); mRNA levels (RT-PCR) of Il-1β, Il-6, Il-10, VEGF, TNF-α (n=3; 12, 18 h) and DSPP (n=3; 24, 72, 120 h). Data analysis included Shapiro-Wilk, Levene, and generalized linear models (α=0.05). Results demonstrated that cell proliferation increased over time for all groups, and was not impacted by TiO2-nt (p>0.05). GIC groups displayed lower MTT values compared to cells cultured without GIC discs (p=0.019); disregarding the presence of TiO2. Remarkably, TiO2-nt reversed the effect of GIC, reducing the levels of selected biomarkers. LPS treatment modified the expression of the immune-inflammatory markers by MDPC-23 cells (p<0.0001). Morphological analysis did not reveal distinctions for any of the studied. TiO2-nt modulated immune-inflammatory and dentin marker expression by MDPC-23 cells cultured on conventional GIC discs, and did not affect cell morphology/viability, regardless LPS exposure. In conclusion, TiO2-nt may become a reliable clinical strategy to encourage pulp tissue repair.

Cell viability assessment and ion release profiles of GICs modified with TiO2- and Mg-doped hydroxyapatite nanoparticles

ObjectivesTo assess and compare the cell viability and ion release profiles of two conventional glass ionomer cements (GICs), Fuji IX and Ketac Molar EasyMix, modified with TiO2 and Mg-doped-HAp nanoparticles (NPs). MethodsTiO2 NPs, synthesized via a sol–gel method, and Mg-doped hydroxyapatite, synthesized via a hydrothermal process, were incorporated into GICs at a concentration of 5 wt.%. The biocompatibility of prepared materials was assessed by evaluating their effects on the viability of dental pulp stem cells (DPSCs), together with monitoring ion release profiles. Statistical analysis was performed using One-way analysis of variance, with significance level p < 0.05. ResultsThe addition of NPs did not significantly affect the biocompatibility of GICs, as evidenced by comparable decreased levels in cell viability to their original formulations. Distinct variations in cell viability were observed among Fuji IX and Ketac Molar, including their respective modifications. FUJI IX and its modification with TiO2 exhibited moderate decrease in cell viability, while other groups exhibited severe negative effects. While slight differences in ion release profiles were observed among the groups, significant variations compared to original cements were not achieved. Fluoride release exhibited an initial “burst release” within the initial 24 h in all samples, stabilizing over subsequent days. ConclusionsThe addition of NPs did not compromise biocompatibility, nor anticariogenic potential of tested GICs. However, observed differences among FUJI IX and Ketac Molar, including their respective modifications, as well as induced low viability of DPSC by all tested groups, suggest the need for careful consideration of cement composition in their biological assessments. Clinical significanceThe findings contribute to understanding the complex interaction between NPs and GIC matrices. However, the results should be interpreted recognizing the inherent limitations associated with in vitro studies. Further research avenues could explore long-term effects, in vivo performance, and potential clinical applications.

SEM analysis of the endodontic cavity wall after removal of restorative materials used as temporary restoration.

The aim of the present in vitro study was to analyze the endodontic cavity walls for presence of remnants of conventional glass ionomer cement and flowable light cure composite used as temporary restorative materials of endodontically treated teeth. The dentine surface of the access cavity was observed with scanning electron microscopy after the final removal of the temporary restoration using high-speed turbine and diamond bur or ultrasonic device and diamond tip.

ИСЛЕДОВАНИЕ КОМПОЗИЦИОННЫХ МАТЕРИАЛОВ НА ОСНОВЕ АЛЮМОФТОРСИЛИКАТНОГО СТЕКЛА

The results of a comparative analysis of dental glass ionomer cements are compared: "AHfil +" (AHL, United Kingdom), "Ketac Molar Easymix" (3M ESPE, USA), "Fuji IX GP" (GC, Japan), "ProGlass Nine" (Silmet , Israel), "Polyacrylin" (TechnoDent, Russia), "Cemion" (VladMiVa, Russia), "Kemfil" (StomaDent, Russia) and "Glassin Rest" (Omega-Dent, Russia) in terms of working time, hardening time, strength compression, radiopacity, microstructure and chemical composition. It is shown that the main component of the powders of these GICs is crushed calcium ("Kemfil"), strontium ("AHfil +", "Cemion" and "Fuji IX GP"), calcium-strontium ("ProGlass Nine", "Polyacrylin" and "Glassin Rest") and lanthanum-calcium aluminofluorosilicate glass ("Ketac Molar Easymix"). All of them contain phosphorus. Differences in powder granulometric composition indicate a difference in the technology of glass grinding during their production. The working time of the studied GICs is from 1 to 3.5 minutes. The requirements of GOST 31578-2012 and ISO 9917-1:2007 do not correspond to "ProGlass Nine" (36 ± 3 MPa), "Kemfil" (68±6 MPa) and "Glassin Rest" in terms of strength, and "ProGlass Nine" in hardening time. "Fuji IX GP" has the highest strength (201 ± 33 MPa), the rest of the GIC - 142-169 MPa. All studied GICs, with the exception of the non-radiopacity "ProGlass Nine", have a radiopacity corresponding to 1 mm of aluminum. According to the results of the tests, "AHfil +", "Ketac Molar Easymix", "Fuji IX GP", "Polyacrylin" and "Cemion" are recommended for clinical use by dentists

Comparison of physical and mechanical properties of three different restorative materials in primary teeth: an in vitro study

Physical and mechanical properties of three different (Ketac Molar Easymix, Dyract XP, Cention N (CN)) restoratives with different ingredients were evaluated. Four groups were obtained; Group 1: CN LightCure, Group 2: CN SelfCure, Group 3: Ketac Molar Easymix and Group 4: Dyract XP. Disk-shaped samples (n = 10) were prepared and evaluated for the surface roughness test using a profilometer. For the flexure strength test, 2 × 2 × 25mm bar-shaped samples (n = 10) were prepared, and a three-point bending test was applied to the samples. After preparing cavities for microleakage tests, teeth were restored with restoratives, immersed in dye, and microleakage was assessed. For the microtensile bond strength (µTBS) test, ten sticks were obtained for each group and were stressed under tension. According to surface roughness tests, CN SelfCure showed the lowest value (0.13μm), while Ketac Molar Easymix showed the highest value (0.28μm), and significant differences were found between the groups. In flexural strength tests, the highest values were seen in CN SelfCure (82.94MPa), with statistically significant differences between the groups. When CN SelfCure was applied with an adhesive, the teeth showed statistically decreased leakage than other groups on the gingival side. Higher leakage values were seen on the gingival side than the occlusal side in most groups, and the SelfCure groups showed decreased leakage than the LightCure groups. According to µTBS tests, the highest value was obtained in CN SelfCure-Adhesive group, while the lowest was in CN LightCure-Non-adhesive group. When µTBS was evaluated regardless of adhesive use, the SelfCure groups showed higher µTBS values than the LightCure groups. As a result of the µTBS and microleakage test, the difference between the use of CN with and without adhesive, regardless of the polymerization type, was found to be significant (p < 0.05). Cention N showed better properties in SelfCure mode, compared to the rest materials tested, but further in vitro and in vivo studies are needed to investigate the effect of different polymerization modes and the oral environmental conditions.

Diatomaceous earth as a drug-loaded carrier in a glass-ionomer cement

The effect of a natural filler (diatomaceous earth [DE], a promising drug-delivery agent) and its content was investigated on the performance of a model glass-ionomer cement (GIC). Three sample series, differing in DE content (0, 2.5 and 5 wt%), were prepared using a commercial GIC as a matrix (3M Ketac Molar Easymix). The resultant surface microhardness and roughness, wear performance, and compressive strength of the samples were measured after the samples had been stored in deionized water at 37°C for a fixed time. Moreover, the film thickness was tested for the freshly mixed samples. The numerical data was subjected to statistical analysis, in order to test the null hypotheses of the equality of the measured properties between the reference and the DE-modified samples. According to the results, diatomaceous earth particles are uniformly distributed in the GIC matrix, and the cavities of frustules tend to be filled with the GIC. This translates into the observed performance of the DE-loaded GIC. Compared with the reference material (0 wt% DE), the surface microhardness (2.5 wt% DE, p = 0.014; 5 wt% DE, p = 0.005) and roughness (e.g. Ra; 2.5 wt% DE, p = 0.003; 5 wt% DE, p < 0.001) are increased. No effect on the wear performance (p = 0.530 and 0.256, respectively) or compressive strength (p = 0.514) was noticed in the case of DE partially substituting the glass phase. Based on the study results, it is evidenced that diatom frustules are a suitable filler for application in conventional glass-ionomer cements as the glass-substituting drug-loaded carrier. Notably, however, the surface finish method of the DE-filled materials needs development.

Comparison of capsule-mixed versus hand-mixed glass ionomer cements Part II: Porosity

Glass ionomer restorative cements (GIC) are routinely used in dental practice. During mixing, air incorporation may lead to higher porosity with subsequent weakening of the cement. The degree of porosity will determine whether capsule-mixed or hand-mixed GIC are mechanically stronger for clinical use. To compare the porosity of four commercially available dental glass ionomer cements, supplied in both hand mix and capsule-mix formulations, by evaluating number of voids (%), total volume of voids (mm3 ) and volume percentage of voids (%). Eighty samples were manufactured from hand-mixed GIC: Riva Self Cure; Fuji IX GP ; Ketac Universal, Ketac Molar Easymix, and equivalent capsule-mixed GIC: Riva Self Cure; Fuji IX GP ; Ketac Universal Aplicap and Ketac Molar Aplicap. Micro-CT scanning was used to evaluate porosity. The number of voids (mm3 ), total volume of voids (mm3 ) and the volume percentage of voids (%) were calculated.

Comparison of capsule-mixed versus hand-mixed glass ionomer cements Part 1: compressive strength and surface hardness

Dental restorative glass ionomer cements (GIC) are available as hand-mixed or capsulated products. Capsulation facilitates uniform ratios of powder to liquid, that should result in an optimal end-product. If this is evident, the degree to which capsulated GIC are mechanically stronger will aid in deciding when to use them instead of the handmixed variety. The compressive strength and surface hardness of hand mixed GIC were compared to capsule-mixed equivalents. Eighty samples were manufactured from hand-mixed GIC: Riva Self Cure; Fuji IX GP; Ketac Universal, Ketac Molar Easymix, and equivalent capsule-mixed GIC: Riva Self Cure; Fuji IX GP; Ketac Universal Aplicap and Ketac Molar Aplicap. Compressive fracture strength was tested using a universal testing apparatus. Surface hardness was measured with a Vickers digital micro-hardness tester Significant differences were found between the compressive strength of RSCH and RSCC (P = 0.027), and, between KMH and KMC (P &lt; 0.001). Significant differences in surface hardness were found between FIXH and FIXC (P = 0.031),KUH and KUC (P &lt; 0.001), as well as KMH and KMC (P = 0.006). Three capsulated forms of GIC (RSCC, KUC, KMC) demonstrated superior mechanical properties. Capsulated GIC offer advantages which may translate to clinical application.

Initial Mechanical Stabilization of Conventional Glass Ionomer Cements with Different Active Principles

Objective: To determine the initial mechanical stabilization of conventional glass ionomer cements (GICs) indicated for the atraumatic restorative treatment (ART) in different storage periods. Material and Methods: Specimens were divided according to the GIC (n=12): IZ - Ion-Z, KM - Ketac Molar Easymix, RS - Riva Self Cure, and GL - Gold Label 9. They were prepared and stored in distilled water. Superficial microhardness (SMH) was evaluated (KHN) in three phases: (A) after 1, (B) 3, and (C) 7 days of storage. Data were submitted to 2-way ANOVA and Tukey tests (α = 5%). Results: The average KHN values for phases A, B, and C were, respectively, 33.05 ± 9.74; 33.21 ± 10.31 and 52.07 ± 11.75 (IZ); 50.35 ± 11.39; 66.05 ± 10.48 and 67.77 ± 13.80 (KM); 89.63 ± 15.59; 71.31 ± 23.86 and 57.70 ± 16.89 (RS); 42.18 ± 9.03; 68.54 ± 6.83 and 57.95 ± 8.24 (GL). Significant differences were observed: GIC, time, and interaction of both (p<0.05). KHN values differed between the groups, except in the GIC parameter for KM and GL. The time parameter values of phase A were lower than those of B and C, except for IZ and RS. Conclusion: The initial mechanical stabilization differed between the types of GIC tested and the storage time, and after the final period, all had similar SMH.

Porosity and pore size distribution in high-viscosity and conventional glass ionomer cements: a micro-computed tomography study.

ObjectivesThis study aimed to compare and evaluate the porosity and pore size distribution of high-viscosity glass ionomer cements (HVGICs) and conventional glass ionomer cements (GICs) using micro-computed tomography (micro-CT).Materials and MethodsForty cylindrical specimens (n = 10) were produced in standardized molds using HVGICs and conventional GICs (Ketac Molar Easymix, Vitro Molar, MaxxionR, and Riva Self-Cure). The specimens were prepared according to ISO 9917-1 standards, scanned in a high-energy micro-CT device, and reconstructed using specific parameters. After reconstruction, segmentation procedures, and image analysis, total porosity and pore size distribution were obtained for specimens in each group. After checking the normality of the data distribution, the Kruskal-Wallis test followed by the Student-Newman-Keuls test was used to detect differences in porosity among the experimental groups with a 5% significance level.ResultsKetac Molar Easymix showed statistically significantly lower total porosity (0.15%) than MaxxionR (0.62%), Riva (0.42%), and Vitro Molar (0.57%). The pore size in all experimental cements was within the small-size range (< 0.01 mm3), but Vitro Molar showed statistically significantly more pores/defects with a larger size (> 0.01 mm3).ConclusionsMajor differences in porosity and pore size were identified among the evaluated GICs. Among these, the Ketac Molar Easymix HVGIC showed the lowest porosity and void size.

Titanium dioxide nanotubes added to glass ionomer cements affect S. mutans viability and mechanisms of virulence.

This in vitro study evaluated the impact of TiO2 nanotubes (n-TiO2) incorporated into glass ionomer cement (GIC) on Streptococcus mutans (S. mutans) characteristics at cellular and molecular levels. n-TiO2, synthesized by the alkaline method (20 nm in size), was added to Ketac Molar EasyMix® at 0%, 3%, 5%, and 7% by weight. S. mutans strains were cultured on GIC disks with addition or not of n-TiO2 for 1, 3, and 7 days and the following parameters were assessed: inhibition halo (mm) (n=3/group); cell viability (live/dead) (n=5/group); cell morphology (SEM) (n=3/group); and gene expression by real-time PCR (vicR, covR, gtfB, gtfC, and gtfD) (n=6/group). The data were analyzed by the Kruskal-Wallis test, repeated-measures ANOVA or two-way ANOVA, and Tukey's and Dunn's post-hoc tests (α=0.05). The agar diffusion test showed a higher antibacterial property for 5% n-TiO2 compared with 3% and 7% (p<0.05) with no effect of time (1, 3, and 7 days). The cell number was significantly affected by all n-TiO2 groups, while viability was mostly affected by 3% and 5% n-TiO2, which also affected cell morphology and organization. Real-time PCR demonstrated that n-TiO2 reduced the expression of covR when compared with GIC with no n-TiO2 (p<0.05), with no effect of time, except for 3% n-TiO2 on vicR expression. Within-group and between-group analyses revealed n-TiO2 did not affect mRNA levels of gtfB, gtfC, and gtfD (p>0.05). Incorporation of n-TiO2 at 3% and 5% potentially affected S. mutans viability and the expression of key genes for bacterial survival and growth, improving the anticariogenic properties of GIC.

Long term Fluoride Release of Newly Developed Alkasite Based Restorative Material

Abstract: Glass ionomer cement in dentistry prevents demineralization process through its fluoride release property and is effective in the induction of remineralization phase. Being low of flexural strength of glass ionomer has caused the search for different materials that can release fluoride. In this study, fluoride release of new alkasite based filling material which has been developed as an alternative to glass ionomer cement has been evaluated. Three commercially available filling materials were tested for the present study: Traditional glass ionomer (Ketac Molar Easymix, 3M ESPE, Germany), resin modified glass ionomer (Nova Glass LC, Imicryl, Konya,Turkey) and Alkasite filling (Cention N, Ivoclar, Vivadent,Schaan, Liechtenstein). Fluoride release of three filling materials were measured at certain intervals for 63 days. Nova Glass LC, Ketac Molar easymix and Cention N released fluoride throughout the study. Fluoride releases of Nova Glass LC for the first 24 hours were significantly higher than Ketac Molar and Cention N group (p&amp;lt;0.05). It has been observed that Cention N can release fluoride in the long term just like Ketac Molar Easymix and Nova Glass LC glass ionomer cement.

Wear, roughness and microhardness analyses of single increment restorative materials submitted to different challenges in vitro.

To evaluate the microhardness, roughness, profilometry and cross-sectional hardness of single increment materials submitted to different challenges. Thirty-six disks of each material, Filtek Supreme XTE (FT), Filtek One Bulk Fill (BK), Ketac Molar Easy Mix (KT) and Equia Forte + Coat (EQ) were immersed in saliva, pH cycling and Coke for 15days. Half of each surface was used as its own control. Superficial microhardness, roughness, perfilometry analysis were performed. All samples were sectioned, embedded in acrylic resins, polished and cross-sectional hardness were made. Data were analyzed by ANOVA and Tukey's test (p < 0.05). The KT presented superficial microhardness superior than EQ. However, in depth, EQ showed superior values. FT, KT suffered the effects of challenges on microhardness values. The highest roughness and wear values were found for KT. RC do not suffer wear. All materials suffered the effects of Coke and pH challenges in depths 10µm and 60µm. The single increment restorative material that suffered less action on its surface was the bulk-fill resin. The coat present in the hybrid ionomer was able to resist to the immersion actions. In addition, Coke was the most aggressive challenge.

Evaluation of mechanical properties of fluoride-releasing dental materials after multiple fluoride recharge/discharge application

This study aimed to determine the mechanical properties of fluoride-releasing dental materials after an accelerated fluoride recharge/discharge procedure. Two fluoride-releasing glass ionomer types of cement (Ketac Molar Easymix and IonoStar Molar), a resin-modified glass ionomer (Photac Fil Quick Aplicap), and two compomers (Compoglass F and Glasiosite) were used in this study. A total of 30 rectangular specimens and 30 disk specimens of each material were prepared and placed in distilled/deionized water (n = 5). The amount of fluoride released was analyzed from the materials for 7-day discharge, 1st recharge, 7-day discharge, 2nd recharge, and 7-day discharge, and 3rd recharge. The de/pre- and post-recharge fluoride release were measured using an ion chromatography for 24 days. The flexural strength and microhardness of each group were evaluated. The microhardness of all restorative materials showed no significant change (p &gt; 0.05) over the experimental period. The flexural strength properties of the restorative materials did not change within the time of the study. The study showed that the fluoride release/uptake causes no effect on the mechanical and physical properties of dental materials.

The effect of magnesium oxide nanoparticles on the antibacterial and antibiofilm properties of glass-ionomer cement

ObjectivesThis study examined the antibacterial and antibiofilm properties of conventional glass-ionomer cement (GIC) modified by the addition of magnesium oxide (MgO) nanoparticles. Materials and methodsMgO nanoparticles were characterised by XRD, FTIR, and SEM analysis and tested for its activity against Streptococcus mutans and Streptococcus sobrinus. MgO nanoparticles were incorporated into GIC powder (Ketac Molar Easymix) at different concentrations and the antibacterial and antibiofilm activity was evaluated using agar disk diffusion and biofilm-CFU counting assays. ANOVA and Tukey's post hoc tests were used for the analysis, and the level of significance was set at p < 0.05. ResultsMgO nanoparticles showed antibacterial activity against both microorganisms (MIC = 500 μg/ml and MBC = 1000 μg/ml). A significant difference in the zones of inhibition was detected (p < 0.005). The effect was evident in the 2.5% MgO nanoparticle modified GIC while the CFU counting biofilm assay showed the effect of the added nanoparticles from 1% with a significant difference between the tested material groups (p < 0.005). ConclusionsThe MgO nanoparticle modified GIC showed effective antibacterial and antibiofilm activity against two cariogenic microorganisms and could be considered for further development as a biocompatible antibacterial dental restorative cement.

Influence of the cleaning method employed prior to the use of ionomeric materials in micro filtration of cavities at the cervical level

Objective: To evaluate the influence of the cleaning of the cavity with aluminum oxide and pumice on the marginal microfiltration when using ionomeric materials (IV). Materials and Methods : In 40 human premolar teeth, cavities were prepared at the level of the cemetery amelo, the teeth were randomly divided into 4 groups (n: 10) received cleaning and restoration procedures according to the group, G1 cleaning with abrasive air and restoration with IV Ketac Molar Easy Mix (IVKM), G2 abrasive air and restoration with IV Gold Label 2 (IVGL), G3 pumice stone and IVKM, G4 pumice stone and IVGL. After the process of thermal aging, pigmentation with methylene blue and cutting in the lingual buccal direction, the fragments with the highest integrity were analyzed to the stereomicroscope by three evaluators who established the degree of micro filtration at the cervical and occlusal levels; the average obtained by surface per tooth was analyzed statistically. Results: The analysis performed revealed normality in the data, finding through the Tukey test that all groups are equal, with no difference in treatment and material used. Conclusions: Micro filtration was evident in all the groups independent of the cleaning treatment and the restoration material used, most notably at the level of the cervical wall.

Effects of the reinforced cellulose nanocrystals on glass-ionomer cements

ObjectiveGlass-ionomer cements (GICs) modified with cellulose nanocrystals (CNs) were characterized and evaluated for compressive strength (CS), diametral tensile strength (DTS) and fluoride release (F−). MethodsCommercially available GICs (Maxxion, Vidrion R, Vitro Molar, Ketac Molar Easy Mix and Fuji Gold Label 9) were reinforced with CNs (0.2% by weight). The microstructure of CNs and of CN-modified GICs were evaluated by transmission electron microscopy (TEM) and by scanning electron microscopy (SEM) while chemical characterization was by Fourier transform infrared spectroscopy (FTIR). Ten specimens each of the unmodified (control) and CN-modified materials (test materials) were prepared for CS and DTS testing. For the fluoride release evaluation, separate specimens (n=10) of each test and control material were made. The results obtained were submitted to the t-test (p<0.05). ResultsThe CN reinforcement significantly improved the mechanical properties and significantly increased the F− release of all GICs (p<0.05). The GICs with CNs showed a fibrillar aggregate of nanoparticles interspersed in the matrix. The compounds with CNs showed a higher amount of C compared to the controls due to the organic nature of the CNs. It was not possible to identify by FTIR any chemical bond difference in the compounds formed when nanofibers were inserted in the GICs. SignificanceModification of GICs with CNs appears to produce promising restorative materials.

Atraumatic restorative treatment-ART in early childhood caries in babies: 4years of randomized clinical trial.

To assess the effectiveness of atraumatic restorative treatment (ART) performed 4years ago in babies suffering from early childhood caries (ECC), and to compare the clinical performance of ART atraumatic restorations performed with two different high-viscosity glass ionomer cements (GIC). This was a longitudinal follow-up of a randomized, double-blind, split-mouth-type clinical trial. The initial sample was composed of 100 deciduous molars with occlusal lesions in 25 children with ages between 18 and 36months who received ART with two different GICs: Ketac Molar Easymix® (3M ESPE) and Vitro Molar® (DFL). The clinical assessments were performed by a trained, blind examiner gauged by the parameters assessed in 1, 2, and 4years (ART and USPHS criteria). For the analysis of the clinical performance of ARTs between the different GICs, the chi-square and Mann-Whitney tests were applied (p < 0.05). In the 4years of evaluation, the sample was composed by 76 ARTs and 19 children, with 94.7% of the treatments having inactivated the cavity process. The total success percentage of the ARTs was 94%, 87.5%, and 82.9%, in 1, 2, and 4years of follow-up, respectively. Moreover, among the GICs studied, this difference was not statistically significant (p > 0.05) ( ClinicalTrials.gov NCT03756025). ART was effective in handling ECC, with an excellent clinical performance of ART restorations, for both GICs, during the 4years of follow-up. ART, with both GIC studied, is an alternative therapy for ECC.

The Impact of Radiotherapy in the in Vitro Remineralization of Demineralized Enamel

Objective: To evaluate the impact of radiotherapy on enamel around restorations of glass ionomer cement (GIC) and fluoride tooth paste (FTP). Material and Methods: Eighty enamel blocks were made and randomly distributed into two groups, according to the fluoride therapy, non-fluoride tooth paste (NFTP) and FTP (n=40) and in subgroups in conformity with radiation dose (0, 10, 30 and 60 Gy). Roughness and microhardness enamel analyses were conducted before radiotherapy. Enamel cavities were made and restored with two GIC (Ketac Molar Easy Mix or Vitremer). Enamel blocks were submitted to 10, 30 and 60 Gy. Then, artificial enamel caries lesions were created by a pH-cycling procedure and FTP or NFTP were used as treatment. The restored enamel blocks were submitted to final roughness and microhardness analyses. Roughness increase (∆R) and hardness loss (∆H) values of enamel were submitted to ANOVA and Tukey test (p=0.05). Results: The irradiated enamel group showed statistically higher ∆R (0.44 ±0.2) and ∆H (99.26±7.0) values compared to non-irradiated group (∆R = 0.051±0.02; ∆H=66.16±12.7) when a resin-modified GIC and NFTP were used. Conclusion: Higher radiation dose increased dissolution of bovine enamel. The use of GIC associated with FTP decreased roughness and increased enamel hardness after radiotherapy.

Effect of ionizing radiation on the properties of restorative materials.

The aim of this study is to evaluate the effect of different doses of the ionizing radiation (0 Gy, 10 Gy, 30 Gy, and 60 Gy) on the physical properties of dental materials. Disc-shaped samples from each material (Ketac Molar Easymix, Vitro Molar, Vitremer, Vitro Fil Lc, Filtek Z 250 and Filtek Z 350) were made for water solubility, sorption analysis (n = 20), microhardness (n = 20), and surface roughness analysis (n = 24). Specimens were divided into four groups, according to radiation dose: control group (0 Gy), 10 Gy, 30 Gy, and 60 Gy. For water solubility and sorption analysis, the specimens were irradiated and were stored for 21 days to calculate the water solubility and sorption values. Microhardness analysis was carried out before and after irradiation doses. For surface roughness analysis, the specimens were submitted to brushing test, and after 24 h, initial surface roughness analysis was made in a rugosimeter. Subsequently, the samples were irradiated and final surface roughness analysis was made. The original water solubility and sorption, surface roughness, and microhardness values were subjected to ANOVA two-way statistical analysis and Paired t-test and Tukey post hoc test (α = 0.05), respectively. Water solubility and sorption values, and surface roughness values presented statistical difference between groups (0, 10, 30 e 60 Gy) for all materials. High doses of ionizing radiation (30 Gy and 60 Gy) increased the surface roughness, sorption, and solubility for the most materials.