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The aim of this study was to evaluate the influence of different surface treatments on bond strength (BS) between composite and a resin cement trough microshear bond strength test. Seventy five discs (10x2 mm) of Filtek P90, Filtek Z250 and Filtek Z350 XT (3M ESPE), were divided into 5 groups according to the treatment: C= control - no treatment; sandblasting J= aluminum oxide (50μm); sandblasting JE = + 99.3% ethanol for 5 min; silica coating S = (3M-ESPE Cojet - 30 microns); SS = silica coating + silane. PVC tubes (0.5 x 0.80 mm) were attached on the composite disc, and then, inserted resin cement (3M ESPE-RelyX ARC). After 24 hours artificial saliva storage at 37oC, the specimens were tested for microshear crosshead speed of 1.0 mm/min. Data were evaluated in two-way ANOVA and Tukey’s test (5%) for contrast. The results showed that sandblasting with aluminum oxide (J) was efficient in increasing the BS for composites Z350 and P90. For the Z250, there were no difference between treatments. Also, CS showed results similar to controls for all composites. SE showed the worst results for Z350 e P90. BS values were dependent on the type of composite and the surface treatment used. Sandblasting with aluminum oxide seems to be an effective surface treatment for composites and may lead to higher BS values, while the use of ethanol could be harmful.

Made available in DSpace on 2021-06-25T10:28:11Z (GMT). No. of bitstreams: 0 Previous issue date: 2021-04-01 Background: This study aimed to evaluate surface treatments, adhesives and composites for repairing silorane based restorations. Material and Methods: One hundred and twenty truncated cones (2 mm smaller diameter and 4 mm larger diameter) made of silorane composite were divided in 12 groups according with the surface treatment (diamond bur and oxide aluminum abrasion), the adhesive (Adper Scothbond Multipurpose (3M ESPE), Ecusit (Voco) and Filtek P90 Adhesive (3M ESPE)). Each group was subdivided in two according with the composite used for repair (methacrylate and silorane). The repair was made with a second truncated cone build over the first one and bond strength assssed by tensile strength. Data were submitted to ANOVA 3-way and Tukey’s test (p

This study compared dimensional stability and adaptability of two resin composites [Filtek P90 and Filtek Supreme XT] after storage in different pH media. Methods: For dimensional stability, cylindrical specimens were prepared either from Filtek P90 or Filtek Supreme XT. Specimens’ dimensions were measured before and after storage in neutral [pH7] or acidic saliva [pH 3.6] for 1 week, 1month or 3 months. Volumetric changes were calculated. For adaptability, 80 class V cavities were made in sound human teeth. The cavities were restored with Filtek P90 or Filtek supreme XT. The adaptation was evaluated using stereomicroscope; before and after storage in acidic or neutral saliva for 1 week,1 or 3 months. Results: Filtek P90 showed significantly higher contraction compared to Filtek Supreme XT only after 3 months storage. After 1 week or 1 month, the difference in volumetric changes between two material was statistically non-significant. The pH of storage media showed non-significant effect on volumetric changes of both composites. For adaptability to cavity walls in acidic saliva, no statistically significant difference was found between gap dimensions at tooth restoration interface for both Filtek P90 and Filtek Supreme XT. However, in neutral saliva, Filtek P90 showed statistically significantly higher mean gap dimensions than Filtek Supreme XT through all time storage. Conclusions: Silorane-based resin composite undergoes volumetric changes comparable to nanohybrid resin composite except on long term storage where it revealed contraction. The adaptation of silorane based composite was worse compared to that of nanohybrid composite in neutral pH media.

The color stability and surface uniformity are very important properties for dental aesthetics. Objective: To evaluate the color stability and surface roughness of different composites after artificial accelerated aging (AAA). Methods: Samples were made using the silorane-based Filtek P90 (3M-ESPE), nanohybrid Tetric N-Ceram (Ivoclar Vivadent), and GC Kalore (GC Company). Ceramic D. Sign (Ivoclar Vivadent) and Ketac N100 (3M-ESPE) resin-modified glass ionomer cement (RMGIC) served as controls. The values for color stability and surface roughness were recorded before and after AAA for non-C-UV (300 hours). Color stability was assessed as the difference between the coordinates obtained from the L*a*b* system. The surface roughness was analyzed with a rugosimeter. The surface value of each sample was taken as the average of these measurements. The one-way ANOVA and Tukey’s post-test with α=5% was used. Results: The greatest change in color stability occurred for the RMGIC (ΔE=18.7) and the least for ceramics (ΔE=2.1). No significant difference was noted among the composites (p>0.05). The surface roughness before and after AAA differed significantly only for the RMGIC (pConclusion: The two latest generation resins (Filtek P90 and GC Kalore) showed good results in terms of color stability and surface roughness for use in aesthetic restorations.

Background. One of the problems with composite resin restorations is gap formation at resin‒tooth interface. The present study evaluated the effect of preheating cycles of silorane- and dimethacrylate-based composite resins on gap formation at the gingival margins of Class V restorations. Methods. In this in vitro study, standard Class V cavities were prepared on the buccal surfaces of 48 bovine incisors. For restorative procedure, the samples were randomly divided into 2 groups based on the type of composite resin (group 1: di-methacrylate composite [Filtek Z250]; group 2: silorane composite [Filtek P90]) and each group was randomly divided into 2 subgroups based on the composite temperature (A: room temperature; B: after 40 preheating cycles up to 55°C). Marginal gaps were measured using a stereomicroscope at ×40 and analyzed with two-way ANOVA. Inter- and intra-group comparisons were analyzed with post-hoc Tukey tests. Significance level was defined at P < 0.05. Results. The maximum and minimum gaps were detected in groups 1-A and 2-B, respectively. The effects of composite resin type, preheating and interactive effect of these variables on gap formation were significant (P

Objectives : The purpose of this study was to evaluate effect of additional light curing on microhardness and microleakage at cervical third of class II silorane-based composite restorations. Methods : Class II cavities were prepared on the proximal surfaces of 20 human premolars. The specimens were randomly divided into two groups of 10. In both groups, class II cavities were restored incrementally (gingival, oblique buccal and oblique lingual) with silorane-based composite (Filtek P90) and cured (group1: occlusal curing; group 2: additional curing from buccal and lingual). The samples were immersed in 0.5% fuchsine and dye penetration was recorded at the four regions of the gingival floor. Also, Vickers hardness test was performed at a distance of 1 mm above the gingival margin. Data were statistically analyzed using ANOVA after the evaluation of normal data distribution with Kolmogorov–Smirnov test at the 0.05 level of significance. Results: The two photo activation methods significantly affected the hardness (p=0.005) and microleakage (p=0.045). Additional light curing increased Vickers hardness when compared to occlusal curing. Comparison of microleakage in different areas of the first group did not show any significant difference (p=0.240) but the differences were significant between the different areas of the second group (p=0.028). Additional light curing decreased dye penetration in the all depths. Only in the H3 and M3, curing technique showed a significant effect on the results. Conclusions : Additional light curing would cause in better hardness and less microleakage. Therefore it is suggested after initial occlusal curing.

Objective: To compare the incidence of microleakage associated with contemporary esthetic restorative-adhesive systems following cyclic wet and dry storage as a representation to the dry mouth condition. Methods: Standardized cervical cavities in both buccal and lingual surfaces of 100 extracted human premolars were restored in 10 groups (n=10 with 20 cavities) using 7 contemporary esthetic restoratives and 3 adhesive systems following their manufacturers’ instructions. Cavities in groups 1–3 were restored with self-adhesive restoratives; conventional glass-ionomer (GI) (Ketac Molar Aplicap), resin modified glass-ionomer (RMGI) (Vitremer) and self-adhesive flowable composite (SAFC) (Fusio Liquid Dentin). Conventional flowable (FC) (Filtek Z350 Flow), nano-hybrid (HC) (Filtek Z250 XT) and nano-filled (NC) (Filtek Z350 XT) methacrylate-based composites were used in conjunction with total-etch, 2-step adhesive (Adper Single Bond 2) to restore cavities in groups 4–6. The same restoratives were also used to restore cavities in groups 8–10 in the presence of self-etch, 1-step adhesive (Adper Easy One), while cavities in group 7 were restored with silorane-based composite (Filtek P90) together with its specific adhesive system. Five restored teeth from each group (10 cavities) were subjected to cyclic storage in wet and dry environment, each for 12h/day and for a total period of 30days, while the other 5 were tested with no cyclic storage to serve as control. Using dye penetration technique, the associated microleakage was then scored from 0 to 4 for all restorations according to the depth of dye penetration at both occlusal and gingival interfaces. The incidences of each score were recorded in percentages and the numerical microleakage data were statistically analyzed using Kruskal–Wallis and Mann–Whitney comparisons at α=0.05 to stand on the significance of differences detected between groups. Results: All restorative systems showed incidences of microleakage before and following cyclic storage in wet and dry environment with no specific manner declared for any. Statistical analysis of the scored data revealed no difference between different restorative systems under no storage condition, however HC, S and FC in groups 5, 7 and 8 showed higher rates of microleakage when subjected to cyclic wet-dry storage (Mann–Whitney, P0.05). For each restorative system, no significant difference (Kruskal–Wallis, P>0.05) was recorded between microleakage values recorded at occlusal and gingival interfaces. Conclusion: Occlusal and gingival sealing ability of flowable resin composite bonded with self-etch, 1-step adhesive is the most affected following cyclic wet-dry storage. Selection of such restorative option accordingly is not suggested for patients suffering from dry mouth.

Made available in DSpace on 2021-06-25T10:19:01Z (GMT). No. of bitstreams: 0 Previous issue date: 2020-01-27 Composites have been proven to have a cytotoxic effect on a variety of tissues and cells. Aim: The aim of this study was to analyse the degree of conversion of resins and its correlation with the cell viability in primary gingival fibroblasts. Methods: Resin-based silorane (Filtek P90) and conventional methacrylate resins (Filtek Z100, Filtek Z250 and Filtek Z350XT) were used to evaluate cell viability and the degree of conversion. The resins were light-cured by a LED for 20 and 40 seconds. The degree of conversion was analysed by Fourier transform infrared spectroscopy. Cellular metabolism was evaluated after 24 hours by the MTT assay (n = 6) using the storage solution of composite resin for either 24 hours or 12 days. Variance analysis (ANOVA) with a Bonferroni correction (p < 0.05) was performed to compare the groups. Results: The composite Filtek P90 showed a higher degree of conversion when polymerised for 40 or 20 seconds, while the composites Filtek Z100, Filtek Z250 and Filtek Z350XT showed similar degree of conversion. Only the Filtek Z100 resin was cytotoxic. Conclusion: We found no statistically significant correlation between cell viability and the degree of conversion. Department of Restorative Dentistry Faculty of Dentistry Federal University of Minas Gerais (UFMG) Department of Chemistry Paulista State University (UNESP) Department of Chemistry Paulista State University (UNESP)

RESUMEN Introduccion: Las resinas dentales basadas en siloranos, son el resultado de la union quimica de siloxanos y oxiranos. Dentro del proceso de evolucion de las resinas, se han modifcado sus formulaciones para optimizar sus propiedades fisicas, mecanicas y esteticas. Sin embargo, aun presentan problemas como la contraccion de polimerizacion, problemas alergicos y toxicologicos. Objetivo: Determinar el potencial efecto citotoxico de las resinas a base de siloranos sobre la viabilidad celular en un cultivo de fbroblastos de la linea L929. Metodologia: Se estudio la exposicion de fbroblastos de raton L929 a resinas dentales a base de siloranos Filtek p90 y metacrilatos Filtek p60 en tres tiempos de fotocurado durante 6 dias. Se evaluo el efecto sobre la viabilidad celular mediante pruebas de exclusion vital, micrografias electronicas y composicion elemental de superfcie (Mg, Na, K y Ca) por ESEM/EDAX. Resultados: La resina Filtek p90 mostro un mayor efecto citotoxico a tiempos de fotocurado prolongados (20 segundos o mas) respecto a la resina Filtek p60. El efecto resulto mas marcado para 20 segundos de fotocurado, ya que las concentraciones de Ca y K en la superfcie celular fueron las mas afectadas. Conclusiones: La resina dental Filtek p90 ejerce un efecto citotoxico relativamente bajo sobre las celulas de fbroblastos L929 (p

Introduction:Hardness is one of the basic properties of dental materials, specially composite resins which is relevant to their polymerization. The aim of this study was to evaluate the effect of light curing distance and the color of clear Mylar strips on surface hardness of Silorane-based (SCR) and Methacrylate-based composite resins (MCR).Materials and methods:40 samples of MCRs (Filtek Z250) and SCRs (Filtek P90) were prepared in size of 5 mm×2 mm (80 samples in total). The samples divided into 8 groups (10 samples in each one) based on the color of clear Mylar strips (white or blue) and distance from light curing source (0 mm or 2 mm). All the samples cured for 40 second and stored in incubator for 24 hours in 37°C temperature. Surface hardness test was done by Vickers test machine and the collected data were analyzed by one-way ANOVA and paired T-test by using SPSS software version 13 at significant level of 0.05.Results:MCRs cured with blue Mylar strips from 0 mm distance had the highest (114.5 kg/mm2) and SCRs cured with white Mylar strips from 2 mm distance had the lowest (42.2 kg/mm2) mean of surface hardness. Also, the results of comparison among SCRs and MCRs showed significant differences among all groups (all P values Conclusion:The hardness decreased as the distance increased and the blue Mylar strips provided higher hardness than clear ones. Also, Filtek Z250 showed higher hardness compared to Filtek P90.

Objectives This study aimed to assess the effect of 38% carbamide peroxide on the microleakage of class V cavities restored with either a silorane-based composite or two methacrylate-based composites. Materials and Methods A total of 96 class V cavities were prepared on the buccal surface of extracted human teeth with both enamel and dentin margins and were randomly assigned into three groups of Filtek P90 (3M-ESPE) + P90 system adhesive (3M-ESPE)(group A), Filtek Z250 (3M-ESPE) + Adper Prompt L-Pop (3M-ESPE)(group B) and Filtek Z350XT (3M-ESPE) + Adper Prompt L-Pop (group C). Half of the teeth were randomly underwent bleaching (38% carbamide peroxide, Day White, Discus Dental, applying for 15 min, twice a day for 14 day) while the remaining half (control) were not bleached. Dye penetration was measured following immersion in basic fuchsine. Data were statistically analyzed using Kruskal-Wallis and Mann-Whitney U tests at a level of 0.05. Results No significant differences were found between composites in the control groups in enamel (p = 0.171) or dentin (p = 0.094) margins. After bleaching, microleakage of Z250 (in enamel [p = 0.867] or dentin [p = 0.590] margins) and Z350 (in enamel [p = 0.445] or dentin [p = 0.591] margins) did not change significantly, but the microleakage of P90 significantly increased in both enamel (p = 0.042) and dentin (p = 0.002) margins. Conclusions No significant differences were noted between the bleached and control subgroups of two methacrylate-based composites in enamel or dentin margins. Microleakage of silorane-based composite significantly increased after bleaching.

Objective: The durability of bonded interface between silorane (SIL) and methacrylate-based (MET) composite resins wasn’t investigated yet. The purpose was to evaluate the repair strength (RS) and nanoleakage of the SIL repair using silorane- or methacrylate-based materials immediately [IM] or after 6 months of water storage [6M]. Materials and Methods: fifteen resin blocks (Filtek P90, 3MESPE) were polished, sandblasted with 50-µm aluminum oxide sandblasting and cleaned with 37% phosphoric acid. Then the specimens were divided into three groups: SIL-SIL (adhesive and composite resin); SIL-MET (silorane adhesive and methacrylate based composite) and MET-MET (methacrylate-based adhesive and composite resin) were used for the repair. Composite-composite bonded sticks (0.9 mm2) were sectioned and divided to be tested in tension (1.0 mm/min) IM or 6M. Two sticks from each tooth, at each time, were immersed in a 50% silver nitrate solution and evaluated by SEM. Data were analyzed by two-way repeated measures ANOVA and Tukey´s tests. Results: The RS of the SIL was not dependent upon the adhesive and composite used for the repair. A significant reduction of the RS was observed for all groups after 6M. Conclusions: Both materials can be used for the repair of the silorane composite, despite degradation occur after 6M.

Purpose To report one year clinical performance of two types of composite (silorane based versus methacrylate based) in class I preparations. Materials and methods A total of 15 patients (9 female and 6 male aged 20–40 years) participated in this study where 30 class I cavities were restored with either Filtek silorane (P90) or a methacrylate based composite (Tetric EvoCeram) representing two main groups (n = 15). Each patient received at least one pair of restoration. The cavity design was restricted to eliminate primary carious lesions. All restorations were subjected to a clinical follow up schedule representing (baseline, 6 months and 12 months) during which, two investigators rated the restorations according to the modified USPHS criteria evaluating marginal integrity, surface roughness, marginal discoloration, color match, anatomic form (wear), recurrent caries, retention of restoration and postoperative sensitivity. The data were collected, tabulated and statistically analyzed at a level of significance (P ≤ 0.05) using Friedman test, Chi-square and Fisher's exact test. Results Regarding the clinical performance of the tested materials there was no statistical significant difference among the different recall periods in all the tested criteria in both materials and no statistical significant difference between group I versus group II at all follow up periods (P > 0.05). In addition Kappa test revealed a statistical agreement between marginal discoloration as well as color match and both marginal integrity and surface roughness (P Conclusion 1-The clinical performance of silorane based composite (Filtek P90) was deemed acceptable after one year; with no obvious advantage compared to methacrylate based composite. 2-The low shrinkage associated with (Filtek P90) may not be a determinant factor for its high clinical performance.

Aims and Objectives: The purpose of this in vitro study was to investigate the effect of polishing systems on the microleakage of three different restorative materials (Ketac Molar Easymix, Ketac N100 and Filtek P90). Materials and Methods: Class V cavities were prepared at the cemento-enamel junction of 60 freshly extracted premolars. The prepared teeth were randomly divided into three groups and restored with the three materials. The restored teeth were stored in distilled water at 37°C for 1 week. The restored teeth were then divided into two subgroups (polished and not polished) of 10. Finishing and polishing of the polished group was done using the Sof-Lex polishing system. Furthermore, all the restorations were subjected to dye penetration testing. Results: Results showed that maximum microleakage was observed for the not polished group of Filtek P90 and least levels of microleakage were seen for the polished group of Ketac Molar Easymix. Conclusion: There was a significant difference seen when Ketac Molar Easymix was compared with Ketac N100 and Filtek P90 in terms of the extent of microleakage exhibited on polishing of the three materials; with the former exhibiting the least microleakage scores.

Made available in DSpace on 2019-09-12T16:53:37Z (GMT). No. of bitstreams: 0 Previous issue date: 2013 Objectives: This study measured the degree of conversion (DC), sorption, solubility and microhardness of methacrylate (Filtek Z250 and Filtek Z350XT) and silorane-based composites (Filtek P90). Methods: DC was measured using near infrared spectroscopy immediately and 24 h after the photoactivation. Sorption and solubility measurements were performed after 24 h, 4 weeks and 12 weeks of storage in water. Knoop microhardness was measured after 24 h and after thermal cycling. The data were statistically analyzed using ANOVA followed by Tukey's, Tamhane or paired t-tests (alpha = 0.05). Results: The DC for P90 (37.22 +/- 1.46) was significantly lower than the Z250 (71.44 +/- 1.66) and Z350 (71.76 +/- 2.84). Water sorption was highest in the Z250 and lowest in the P90. All the tested composites exhibited similar values after 24 h of immersion, and no significant differences were observed. No significant differences were observed between the solubilities of the P90 composite (12 weeks) and the Z250 or Z350 composites (4 weeks). KHN values were less elevated for the P90 composite and similar for the Z250 and Z350 composites. An effect of thermal cycling on KHN values was observed for all the composites (p < 0.001). Conclusions: Silorane produced the lowest DC and KHN values and exhibited lower water sorption and solubility compared to methacrylate- based composites. These differences suggest that silorane composites exhibit better hydrolytic stability after 3 months of water immersion compared to conventional methacrylate-based composites. Clinical significance: Silorane had higher hydrolytic stability after 3 months of water immersion than the methacrylate-based resins, despite the lower values of DC and KHN recorded. (c) 2013 Elsevier Ltd. All rights reserved. [Celerino de Moraes Porto, Isabel Cristina] Univ Fed Alagoas, Dept Restorat Dent, BR-57072970 Maceio, Alagoas, Brazil [Baggio de Aguiar, Flavio Henrique] Univ Estadual Campinas, Dept Restorat Dent, BR-13414903 Sao Paulo, Brazil [Brandt, William Cunha] Univ Santo Amaro, Dept Dent, BR-04829300 Sao Paulo, Brazil [Susy Liporoni, Priscila Christiane] Universidade de Taubaté (Unitau), Dept Restorat Dent, BR-12020340 Sao Paulo, Brazil

Objectives This study aimed to compare the micro-tensile bond strength of methacrylate resin systems to a silorane-based restorative system on dentin after 24 hours and six months water storage. Material and Methods The restorative systems Adper Single Bond 2/Filtek Z350 (ASB), Clearfil SE Bond/Z350 (CF), Adper SE Plus/Z350 (ASEP) and P90 Adhesive System/Filtek P90 (P90) were applied on flat dentin surfaces of 20 third molars (n=5). The restored teeth were sectioned perpendicularly to the bonding interface to obtain sticks (0.8 mm2) to be tested after 24 hours (24 h) and 6 months (6 m) of water storage, in a universal testing machine at 0.5 mm/min. The data was analyzed via two-way Analysis of Variance/Bonferroni post hoc tests at 5% global significance. Results Overall outcomes did not indicate a statistical difference for the resin systems (p=0.26) nor time (p=0.62). No interaction between material × time was detected (p=0.28). Mean standard-deviation in MPa at 24 h and 6 m were: ASB 31.38 (4.53) and 30.06 (1.95), CF 34.26 (3.47) and 32.75 (4.18), ASEP 29.54 (4.14) and 33.47 (2.47), P90 30.27 (2.03) and 31.34 (2.19). Conclusions The silorane-based system showed a similar performance to methacrylate-based materials on dentin. All systems were stable in terms of bond strength up to 6 month of water storage.

Aim and Objectives: To comparatively evaluate the microleakage and microgap formation along the gingival margin in class II cavities restored with silorane resin composite and methacrylate resin composite with and without flowable resin liner. Materials and Methods: Sixty human mandibular premolars were distributed into three groups, each group containing 20 teeth (n = 20). Mesial (subgroup A) and distal (subgroup B) box cavities were prepared with gingival margin above and below cemento enamel junction (CEJ), respectively, in each tooth and restored as follows — Group I — Silorane resin composite with self-etch primer and bond (Filtek P90, 3M ESPE MN, USA). Group II — Methacrylate resin composite (Filtek P60, 3M ESPE MN, USA) and self-etch adhesive (Adper Easy one, 3M ESPE MN, USA). Group III — Methacrylate resin composite with self-etch adhesive and a flowable resin liner (Filtek Z350 XT, 3M ESPE MN, USA). The teeth were thermocycled and immersed in 50% silver nitrate solution before sectioning. The specimens were observed under scanning electron microscope for dye penetration and microgap formation. The data was subjected to statistical analysis using Kruskal-Wallis test and Mann-Whitney U test using SPSS version 18. Results: Subgroup A in all the three groups showed significantly less microleakage and microgap formation compared to subgroup B with P < 0.05. Intergroup comparison of subgroup A did not show statistically significant difference, whereas subgroup B showed statistically significant difference for microleakage between group I and group II (P = 0.003), group III and group II (P = 0.002). Conclusion: Silorane resin composite and methacrylate resin with liner showed significantly less microleakage in class II cavities along the gingival margin placed below CEJ compared to methacrylate resin without liner. All the study groups showed less microleakage and microgap formation along the gingival margin placed above CEJ.

Objective: This study evaluated the effect of food-simulating media associated with brushing and coffee staining on color stability of different composite resins. Materials and methods: Eighty specimens were prepared for each composite: Grandio SO (Voco), Amaris (Voco), Filtek Z350XT (3M/ESPE), Filtek P90 (3M/ESPE). They were divided into four groups according to food-simulating media for 7 days: artificial saliva (control), heptane, citric acid and ethanol. The composite surface was submitted to 10,950 brushing cycles (200 g load) in an automatic toothbrushing machine. The specimens were darkened with coffee solution at 37 °C for 24 h. After each treatment, color measurements were assessed by spectrophotometry, using CIE L*a*b* system. The overall color change (ΔE) was determined for each specimen at baseline (C1) and after the treatments (food-simulating media immersion/C2, brushing/C3 and dye solution/C4). Data were analyzed by two-way repeated measures ANOVA and Tukey’s tests (p < .05). Results: The results of RM-ANOVA showed significant differences for composites (p = .001), time (p = .001) and chemical degradation (p = .002). The mean of ΔE for composites were: Z350XT (5.39)a, Amaris (3.89)b, Grandio (3.75)bc, P90 (3.36)c. According to food-simulating media: heptane (4.41)a, citric acid (4.24)a, ethanol (4.02)ab, artificial saliva (3.76)b. For the treatments: dye solution (4.53)a, brushing (4.26)a, after food-simulating media (3.52)b. Conclusions: The composite resin Filtek Z350XT showed significantly higher staining than all other composite resin tested. The immersion in heptane and citric acid produced the highest color alteration than other food-simulating media. The exposure of samples to brushing protocols and darkening in coffee solution resulted in significant color alteration of the composite resins.

Aim This study investigated the effect of TiF4 solution pretreatment on microleakage of silorane and nanofilled methacrylatebased composites in class V cavities. Materials and methods Forty-eight intact premolar teeth were randomly allocated to four groups of 12 teeth. Restorative techniques after standard class V tooth preparations were as follows: Group 1, Filtek P90 composite; group 2, Filtek Z350 XT; group 3, TiF4 solution pretreatment and Filtek P90 composite; group 4, TiF4 solution pretreatment and Filtek Z350 XT. After storing the specimens in distilled water at 37°C for 24 hours and followed by immersion of the specimens in a 0.5% basic-fuchsin solution for 24 hours, they were sectioned buccolingually to obtain four surfaces for each specimen for analysis of microleakage using a stereomicroscope. Data analysis was performed using Kruskal-Wallis test to compare the four groups and the Mann- Whitney test for paired comparisons with Statistical Package for the Social Sciences (SPSS) version 17 software. Results At the enamel margins, microleakage score of the Filtek Z350 XT group was lower than those of the Filtek P90 with and without the application of the TiF4 (p = 0.009 and p = 0.031 respectively). At the dentin margins, groups 3 and 4 (TiF4+Filtek P90 and TiF4+Filtek z350 XT respectively) showed significantly lower microleakage than group 1 (Filtek P90). However, there was no significant difference between other groups (p > 0.05). Conclusion At the enamel margins, microleakage score of the silorane-based composite was more than that of the nanofilled composite. No significant differences were observed between the other groups. At the dentin margins, for the silorane-based composite restorations, TiF4 solution pretreatment resulted in significantly lower microleakage. However, the similar result was not observed for Filtek Z350 XT. Also, no significant difference was observed between microleakage scores of Filtek P90 and Filtek Z350 XT with or without TiF4 pretreatment. Clinical significance In spite of better mechanical and physical properties of modern composites than earlier methacrylate-based composites, polymerization shrinkage has been remaining as one of the main shortcomings of them. Different methods, such as using new low shrinkage resin composites and different dentin pretreatments, have been suggested to overcome this problem. This study evaluated the effect of TiF4 as pretreatment on microleakage of class V tooth preparations restored with a nanocomposite and a silorane-based resin composite. How to cite this article Koohpeima F, Sharafeddin F, Jowkar Z, Ahmadzadeh S, Mokhtari MJ, Azarian B. Role of TiF4 in Microleakage of Silorane and Methacrylate-based Composite Resins in Class V Cavities. J Contemp Dent Pract 2016;17(3):240-247.

Objectives: To evaluate the influence of various photoactivation techniques on the internal gap, Knoop-hardness, and polymerization depth of silorane-and methacrylate-based composites in Class II restorationsMethods: Preparations were made in third molars (n = 10), according to composites (Filtek P60: methacrylate; Filtek P90: silorane) and photoactivation techniques (OC: occlusal photoactivation (control); OBL: occlusal+buccal+lingual photoactivation; and BLO: buccal+lingual+occlusal photoactivation (transdental)). Composites were inserted in two increments, both individually photoactivated for 20s. After 24h, specimens were sectioned and the ratio of internal gaps to interface length (%) recorded. Hardness was tested across the transversal section of restorations (1-4 mm below the surface)Results: Silorane restorations showed significantly lower gaps compared with methacrylate, regardless of polymerization technique (PConclusions: Internal gaps and hardness are affected by composite type and photoactivation. Despite the reduced values, hardness of silorane is not influenced by photoactivation or by depth. Internal gaps are dependent on the energy dose for both composites, with silorane showing lower internal gaps. (Eur J Dent 2012;6:133-140)

AimThe aim of this randomized clinical trial was to compare the proximal contact of a silorane-based resin composite with a conventional methacrylate-based resin composite in class II restorations after a 6 months follow-up period.Materials and methodsAfter obtaining informed consent, 33 patients were randomly allocated into a test group (Filtek P90/Adhesive System-3M ESPE) or control group (Filtek P60/ Adper SE Plus-3M ESPE), and 100 direct resin composite restorations (n = 50) were placed. A single operator performed the cavities and restorations. After rubber dam placement, a metal matrix and wooden wedge were placed. The restorative systems were applied according to the manufacturer's instructions. After 1 week, the restorations were finished and polished. The proximal contacts were assessed blindly and independently by two calibrated examiners (kW = 0.8) at the baseline and after 6 months according to a three-step grading criteria. Data were analyzed with the Mann-Whitney U-test and Wilcoxon signed Rank tests (α = 0.05). Results: After 6 months, 96% of the restoration contacts were present for evaluation. The frequencies of restorations classified as Bravo in control and test groups were 6 and 8% at the baseline, and 6.25 and 12.75% after 6 months. No significant difference was found between the restorative materials (p > 0.05; Mann-Whitney U-test) neither between baseline and 6 months period (p > 0.05; Wilcoxon signed Rank tests).ConclusionBoth materials performed satisfactorily over 6 months follow-up period.Clinical significanceThe short-term clinical performance of a silorane-based resin composite in the proximal contacts of class II restorations was similar to the well-known methacrylate-based resin composite.How to cite this articleGonçalves FS, Castro CDL, Bueno AC, de Freitas ABDA, Moreira AN, Magalhães CS. The Shortterm Clinical Performance of a Silorane-based Resin Composite in the Proximal Contacts of Class II Restorations. J Contemp Dent Pract 2012;13(3):251-256.

Objective This study aimed to evaluate the suitability of one specific silorane-based composite for the application as a repair material for different substrates. Materials and methods Truncated cones of composites fabricated and thermocycled for 6000 cycles to serve as a substrate were made of two commercially available dimethacrylate-based composites (DBC) (Filtek Supreme and Clearfil APX) and one silorane-based composite (SBC) (Filtek P90). The surface of the specimens was treated with air-abraded using Al2O3-particles of 50 µm size. A Teflon device was used to fabricate inverted truncated cones of repair composite over the surface-treated top of each original truncated cone. DBC and SBC were used as repair materials and bonded to the specimens using either a dimethacrylate-based (single bond 2) or a phosphate-methacrylate-based (adhesive belongs to the silorane) adhesives. The specimens were stored in distilled water at 37°C for 7 days and stressed to failure under tension. The data were analyzed with one-way ANOVA and Tukey tests at 5%. Results Bonding DBC as a repair material to a DBC substrate using the dimethacrylate-based adhesive produced the highest bond strength. Bonding DBC as repair material using the phosphate-methacrylate-based adhesive or SBC as repair material using the dimethacrylate-based adhesive produced lower bond strength, regardless the brand and of the chemical formulation of the aged substrate. Conclusion In order to obtain high bond strength, there is need to match adhesive and repair material, regardless the brand and of the chemical formulation of the substrate. How to cite this article Barcellos DC, Pleffken PR, Pucci CR, Pagani C, Gonçalves SEP, Torres CRG. Effectiveness of Silorane-based Composite as a Repair Filling for Dimethacrylate- or Silorane-based Composite Restorations. World J Dent 2012;3(2):161-65.

Background: The purpose of this study was to investigate the behavior of a resin-based 2,2-bis (p-[2′-hydroxy-3′-methacryloxypropoxy] phenylene) propane and a composite resin modified with oxirane, regarding the ability of marginal sealing, both with direct restorations and indirect restorations. Materials and Methods: To achieve this, mesio- and disto-occlusal cavities were made on the same tooth, totalling 100 cavities. These cavities were restored with two materials, Filtek P90 (3M ESPE) and Opallis (FGM). Then, they were divided into two groups: Fifty direct restorations, each sample restored with the two materials, following the manufacturer's protocol and fifty indirect restorations, and then cemented with a paste obtained by diluting the resin in its adhesive. The templates were thermally cycled, 30 s at 5°C and 30 s at 55°C for 500 cycles and then were immersed in methylene blue for 24 h. Afterward, they were trimmed using a plaster trimmer from occlusal toward a gingival direction. These samples were analyzed with stereomicroscope (×3) by two blinded observers. Then, a system which considers the average number of surrounding walls that have suffered infiltration on a scale of 0–3 was used. Results: Data were subjected to statistical analysis (Mann–Whitney and Kruskal–Wallis tests) with a significance level of 5% maximum. Conclusion: It was concluded that the indirect restorations showed the greatest number of restorations with score 0 and 1 (34) and lowest score 2 and 3 (16). This suggests that indirect restorations regardless of the material used behaved more effectively regarding the marginal sealing of restorations.

Aim This study investigated the influence of different composite resin organic matrix (methacrylate – Filtek Z350 XT and silorane – Filtek P90) on light energy transmission through the composite and bottom/top rate. Materials and methods A light-emitting diode (New Blue Phase), light-curing unit was used with different photoactivation protocols (high-continuous mode – HCM, 1400 mW/cm2 for 20 seconds; low-continuous mode – LCM, 700 mW/cm2 for 40 seconds; and soft-start mode – SSM, 140 mW/cm2 for 5s followed by 39 seconds for 700 mW/cm2). Twenty specimens were prepared for each composite. The light energy transmission through the composite was calculated (n=10). The bottom/top rate of the same specimen was calculated (n=10). The data were compared by Tukey's test in different tests (light energy transmission through the composite and bottom/top rate). Results The light energy transmission through the Filtek Z350 XT composite (HCM – 576 mW/cm2, LCM – 238 mW/cm2, SSM – 232 mW/cm2) did not show statistical difference when compared with Filtek P90 composite (HCM – 572 mW/cm2, LCM – 233 mW/cm2, SSM – 230 mW/cm2). The bottom/top rate of the Filtek Z350 XT composite (HCM – 88.98%, LCM – 90.94%, SSM – 89.92%) was statistically higher than that of the Filtek P90 composite (HCM–77.29%, LCM–77.51%, SSM– 77.79%). Conclusion Light energy transmission through the composite was not influenced by the use of different dental composite restoratives. However, the bottom/top rate of the composites was influenced by the use of different dental composite restoratives. Clinical significance Insufficiently polymerized composite resin may present a large number of problems. For this reason, dental composite resins should have the similar deep surface polymerization as the top surface in dental restorations. How to cite this article Guiraldo RD, Consani S, Consani RLX, de Camargo Bataglia MP, Fugolin APP, Berger SB, Lopes MB, Moura SK, Sinhoreti MAC. Evaluation of the Light Energy Transmission and Bottom/Top Rate in Silorane and Methacrylate-based Composites with Different Photoactivation Protocols. J Contemp Dent Pract 2011;12(5):361-367.

The aim of this study was to investigate the influence of different composite resins - Filtek P90 (silorane-based composite) and Heliomolar (methacrylate-based composite) - on light transmission and decrease in Knoop hardness between the bottom and top of cured specimens. The irradiance of a light-curing unit (LCU) was measured with a power meter (Ophir Optronics; 900 mw/cm2) and spectral distributions were obtained using a spectrometer (USB 2000). Twenty standardized cylindrical specimens (2 mm thick x 7 mm diameter) of each composite resin were obtained by curing using the LCU for 40 s. Light energy transmission through the composite was calculated (n=10). The Knoop hardness number for each surface was recorded as the mean of 3 indentations. The difference in Knoop hardness between the top and bottom (DKH) of the same specimen was calculated (n=10). The irradiance of light that passed through Filtek P90 (272 mW/cm2) was not significantly greater than that the passed through Heliomolar (271 mW/cm2). The DKH of Filtek P90 (25%) was significantly higher than that of Heliomolar (12%). There was a greater degree of subsurface polymerization of the methacrylate-based composite compared to the silorane-based composite. O objetivo deste estudo foi avaliar a influência da diferença entre a dureza do topo e da base em compósitos restauradores. Foram utilizados os compósitos restauradores Filtek P90 (compósito à base de silorano) e Heliomolar (compósito à base de metacrilato). A irradiância da unidade foto-ativadodora (UF) foi mensurada com um potenciômetro Ophir Optronics (900 mw/cm2) e o espectro de luz foi obtido usando um espectrofotômetro (USB 2000). Vinte espécimes cilíndricos padronizados (2 mm de espessura por 7 mm de diâmetro) foram obtidos pela fotoativação utilizando UF (40 s) para cada compósito. A irradiância que passou através do compósito foi mensurada (n=10). O número de dureza Knoop para cada superfície foi calculado pela média de 3 penetrações. A diferença da dureza Knoop entre o topo e base (DDK) de um mesmo espécime foi calculada (n=10). A irradiância que passou através da Filtek P90 (272 mW/cm2) não foi estatisticamente superior a Heliomolar (271 mW/cm2). A DDK da Filtek P90 (25%) foi estatisticamente superior a Heliomolar (12%). O compósito a base de metacrilato apresentou melhor grau de polimerização na base quando comparado ao compósito à base de silorano.

Objectives : This in vitro study evaluated the microtensile bond strength (MTBS) of a methacrylate- based compared to a silorane-based resin composite in Class I cavity using different placement techniques.Materials and Methods: Class I cavities with dimension of (4 mm long, 4 mm wide, 3 mm deep) were prepared in extracted sound human molars. The teeth were randomly divided into six groups. The first three groups were filled with Filtek P90 using three methods of insertion; bulk, incremental and snow-plow, and the remaining three groups were filled with Clearfil AP-X using the same three placement techniques. After 24 hours of storage in water at 37°C, the specimens were thermocycled to 1000 cycles. Specimens were prepared for MTBS testing by creating bonded beams obtained from the pulpal floor. Statistical analysis used: Statistical analyses of data were performed by two-way ANOVA/Tukey (α=.05). Results: The experiment showed significant differences between the two resin composites with regard to filling techniques (P0.05). Conclusion: Silorane-based resin composite as opposed to methacrylate based resin composite and layering placements in contrast to bulk filling method had higher microtensile bond strength.

Objective The purpose of this study was to assess the effect of food-simulating liquids on the flexural strength of a methacrylate-based and a silorane-based resin composite. Materials and methods In this in vitro study, sixty specimens of Filtek P90 and Filtek Z350 composite were prepared in a customized mold (2 × 2 × 25 mm). The specimens of each composite were divided into five subgroups as follows: one as a control group and the other four groups included distilled water, heptane, 2% citric acid, and 50% aqueous ethanol. The specimens were stored in the solutions for one week at 37°C, and the control group was stored at room temperature for the same period of time. Then, flexural strength values were measured. The statistical analysis was performed by One-Way ANOVA, Paired T test and post hoc LSD at a significance level of 0.05. Results In the control group, the mean flexural strength of Filtek P90 and Filtek Z350 were 155.1 MPa and 147.3 MPa, respectively, and there was no significant difference (P-value>0.05). The mean flexural strength of Filtek P90 and Filtek Z350 significantly decreased in ethanol (P-value

Objectives The aim of this study was to evaluate the effects of tri-antibiotic paste (TAP) on microtensile bond strengths (MTBS) of dental adhesives to dentin. Materials and methods Sixty extracted molars had their occlusal surfaces flattened to expose dentin. They were divided into two groups, i.e., control group with no dentin treatment and experimental group with dentin treatment with TAP. After 10 days, specimens were bonded using self-etch (Filtek P90 adhesive) or etch-and-rinse (Adper Single Bond Plus) adhesives and restored with composite resin. Teeth were sectioned into beams, and the specimens were subjected to MTBS test. Data were analyzed using two-way ANOVA and post hoc Tukey tests. Results There was a statistically significant interaction between dentin treatment and adhesive on MTBS to coronal dentin (p = 0.003). Despite a trend towards worse MTBS being noticed in the experimental groups, TAP application showed no significant effect on MTBS (p = 0.064). Conclusions The etch-and-rinse adhesive Adper Single Bond Plus presented higher mean bond strengths than the self-etch adhesive Filtek P90, irrespective of the group. The superior bond performance for Adper Single Bond when compared to Filtek P90 adhesive was confirmed by a fewer number of adhesive failures. The influence of TAP in bond strength is insignificant.

This in vitro work had as aim evaluate the effect of photoactivation mode and the distance of light-curing unit (LCU) in microhardness Knoop (KHN) and the diametrical tensile strength (DTS) of methacrylate and silorane-based resins. Filtek Z250 (methacrylate-based resin) and Filtek P90 (silorane-based resin), both from 3M Espe, were selected for this work. The photoactivation were performed by one of the following modes: Valo (Ultradent) at 1000 mW/cm2 X 18 s (S); 1400 mW/cm2 X 12 s (HP); 3200 mW/cm2 X 6 s (PE); and XL 3000 (3M Espe) at 450 mW/cm2 X 40 s (XL). Resin composite were inserted in one increment into a bipartide Teflon matrix (5mm X 2mm) and photoactivated at 0mm, 3 or 6mm from the increment surface, according to the experimental groups. After the confection, the specimens (n=5) were submitted to KHN on the top (T) and on the bottom (B), and to DTS. Data were analyzed through ANOVA/Tukey tests (α=5%). It was observed that Filtek Z250 presented values of KHN equal or higher than Filtek P90. The surface T presented higher values of KHN than B. For both composite resins, the values of KHN on the surface B were lower, as higher the distance of LCU. In relation to DTS, the higher values were observed in Filtek Z250. Silorane base composite resin presented lower mechanical properties when compared to the methacrylate base resin. The distance of LCU is able to influence the microhardness of bottom surface.

The aim of this study was to determine the degradation resistance of three new formulations-silorane-, Ormocer- and dimer-acid-based materials-and compare them to the traditional dimethacrylate-based materials. One silorane- (Filtek P90, P90), one Ormocer- (Ceram-X, CX), one dimer-acid- (N'Durance, ND) and two dimethacrylate-based (Filtek P60, P60; Tetric Ceram, TC) materials were investigated. Water sorption (Wsp) and solubility (Wsl) were determined after the materials were immersed in water for 28 days. Knoop hardness (KH) was determined before and after 24 h immersion in pure ethanol. The flexural-strength (FS) was determined by the bending test after one-week storage in a dry environment or after one-week immersion in pure ethanol. Data were submitted to analysis of variance (ANOVA) and Tukey's test (95%). The three new formulations showed lower Wsp than the dimethacrylate-based formulation. CX (0.50 ± 0.17%) and ND (0.72 ± 0.19%) exhibited the lowest Wsp, whereas P90 (0.02 ± 0.03%) and P60 (0.04 ± 0.03%) showed the lowest Wsl. All resins showed reduced Knoop hardness number (KHN) after ethanol immersion. P60 presented the lowest decrease in KH value (19 ± 5%). TC (48 ± 3%) and P90 (39 ± 9%) showed the highest KHN decrease after ethanol storage. The FS of CX, ND and TC were affected by ethanol storage. The new formulations did not improve the degradation resistance, as compared with the traditional methacrylate-based materials.

Objective The objective was to evaluate and compare the fracture resistance of human maxillary premolars teeth restored with low shrinkage microhybrid composite Silorane-based; Filtek P90 LS, conventional methacrylate-based nanohybrid composite; Ceram X Mono, and two types of fiber-reinforced composites (FRCs); Alert and XENIUS base, micro glass fibers and short glass fibers, respectively in mesio-occluso-distal cavities. Materials and methods A total of 45 human maxillary premolars were selected. Standardized mesio-occluso-distal cavities were prepared in all teeth. Five prepared teeth received no treatment and served as controls (group 1). A total of 40 teeth were randomly divided into four experimental groups (n = 10); group 2: low shrinkage Silorane-based composite, group 3: nanohybrid resin composite, group 4: microfibers reinforced resin composite, and group 5: short fibers reinforced resin composite. Restorations were done for all groups. After being stored 24 h at 37°C, fracture resistance was measured in a universal Instron testing machine by using a 4 mm diameter steel sphere which was applied on tooth buccal and lingual cusps at a cross-head speed of 2 mm/min until fracture occurred. Statistical analysis One-way analysis of variance and Tukey's post-hoc test. Results Highest mean fracture resistance was observed with FRC, nanohybrid, Silorane and lastly with control respectively. Statistically Significant difference was revealed by analysis of variance (P ≤ 0.0001) and Tukey's post-hoc test (P ≤ 0.0001). Conclusion Among the experimental groups, FRC showed the highest fracture resistance.

Objectives This study assessed the effect of water storage on the flexural strength (FS) of low shrinkage composites. Materials and Methods A total of 165 bar-shaped specimens (2 × 2 × 25 mm) were fabricated of 2 low shrinkage composites (Filtek P90 [3M ESPE], GC Kalore [GC International]) and a conventional methacrylate-based composite (Filtek Z250 [3M ESPE]). The specimens were subjected to 3-point bending test at 6 time intervals, namely: immediately after curing, at 24 hours, 1 week, 1 month, 6 months, and 1 year following storage in wet and dry conditions. The FS of the specimens were measured by applying compressive load at a crosshead speed of 1.0 mm/min. Data was analyzed using 3-way analysis of variance (ANOVA) and Tukey's test. Results Three-way ANOVA revealed significant interactions between time, type of composite, and storage condition (p = 0.001). Tukey's multiple comparison test revealed significant reductions in FS of all composites after 6 months and 1 year of storage in distilled water compared to dry condition. Conclusions Filtek P90 showed the highest and GC Kalore showed the lowest FS after 1 year storage in distilled water. The immediate high strength of Filtek Z250 significantly decreased at 1 year and its final value was lower than that of Filtek P90.

Made available in DSpace on 2015-03-18T15:56:24Z (GMT). No. of bitstreams: 0 Previous issue date: 2012-11-01 Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) The aim of this study was to compare the formation of marginal gaps after thermo-mechanical load cycling, between silorane-based and methacrylate-based restorations. Standardized class II cavities were made in 10 permanent human third molars that were restored with the adhesive system Clearfil SE Bond+composite Filtek Z-350 (Methacrylates) and with the composite bonding Filtek P90+P90 (Siloranes), respectively. After 24 h of storage in 100% humidity at 37 degrees C, the restoration margins were stained, photographed, and evaluated. The gap length was calculated as the percentage of the total length of the margins. Thereafter, the specimens were tested by a thermo-mechanical machine and the marginal gap formation of the specimens was re-evaluated. The results were expressed as percentages of gaps and were submitted to a Mann Whitney test at 5% level of significance. Methacrylates showed a statistically significant higher percentage of gaps than Siloranes, both before and after cycling. Univ Sao Paulo, Bauru Sch Dent, Dept Dent Endodont & Dent Mat, BR-17012901 Bauru, SP, Brazil State Univ Sao Paulo, Aracatuba Sch Dent, Dept Operat Dent, BR-16015050 Aracatuba, SP, Brazil State Univ Sao Paulo, Aracatuba Sch Dent, Dept Operat Dent, BR-16015050 Aracatuba, SP, Brazil FAPESP: 09/14762-4

The aim of this study was to evaluate the color stability of composites subjected to different periods of accelerated artificial aging (AAA). A polytetrafluorethylene matrix (10 x 2 mm) was used to fabricate 24 test specimens of three different composites (n=8): Tetric Ceram (Ivoclar/Vivadent); Filtek P90 and Z250 (3M ESPE), shade A3. After light activation for 20 s (FlashLite 1401), polishing and initial color readout (Spectrophotometer PCB 687; BYK Gardner), the test specimens were subjected to AAA (C-UV; Comexim), in 8-h cycles: 4 h exposure to UV-B rays at 50°C and 4 h condensation at 50°C. At the end of each cycle, color readouts were taken and the test ended when the mean value of ΔE attained a level ≥3.30. Tetric Ceram presented alteration in ΔE equal to 3.33 in the first aging cycle. For Filtek P90 and Z250, two (ΔE=3.60) and four (ΔE=3.42) AAA cycles were necessary. After each cycle, there was a reduction of luminosity in all the samples (ΔL). It was concluded that a short period of AAA was sufficient to promote clinically unacceptable color alteration in composites, and that this alteration was material-dependent. O objetivo deste estudo foi avaliar estabilidade de cor de compósitos submetidos a diferentes períodos de envelhecimento artificial acelerado (EAA). Foram confeccionados, em matriz de teflon (10x2 mm), 24 corpos-de-prova de três compósitos (n=8): Tetric Ceram (Ivoclar/Vivadent); Filtek P90 e Z250 (3M ESPE), cor A3. Após fotoativação por 20 s (FlashLite 1401), polimento e leitura inicial de cor (espectrofotômetro PCB 687; BYK Gardner), os corpos-de-prova foram submetidos ao EAA (C-UV, Comexim), com ciclos de 8 h: 4 h de exposições a raios UV-B a 50°C e 4 h de condensação a 50°C. Ao final de cada ciclo, leituras de cor eram realizadas e quando o valor médio de ΔE atingisse índice ≥3,30, o ensaio era encerrado. Observou-se que Tetric Ceram apresentou alteração de ΔE igual a 3,33 já no primeiro ciclo de envelhecimento. Com Filtek P90 foram necessários dois ciclos de EAA (ΔE=3,60) e para Z250 quatro (ΔE=3,42). Observou-se que a cada ciclo ocorria diminuição na luminosidade de todas as amostras (ΔL). Concluiu-se que um curto período de EAA já é suficiente para que compósitos apresentem alteração de cor inaceitável clinicamente e que esta alteração é material dependente.

OBJECTIVES: This study evaluated the effect of lactic acid and acetic acid on the microhardness of a silorane-based composite compared to two methacrylate-based composite resins. MATERIALS AND METHODS: Thirty disc-shaped specimens each were fabricated of Filtek P90, Filtek Z250 and Filtek Z350XT. After measuring of Vickers microhardness, they were randomly divided into 3 subgroups (n = 10) and immersed in lactic acid, acetic acid or distilled water. Microhardness was measured after 48 hr and 7 day of immersion. Data were analyzed using repeated measures ANOVA (p < 0.05). The surfaces of two additional specimens were evaluated using a scanning electron microscope (SEM) before and after immersion. RESULTS: All groups showed a reduction in microhardness after 7 day of immersion (p < 0.001). At baseline and 7 day, the microhardness of Z250 was the greatest, followed by Z350 and P90 (p < 0.001). At 48 hr, the microhardness values of Z250 and Z350 were greater than P90 (p < 0.001 for both), but those of Z250 and Z350 were not significantly different (p = 0.095). Also, the effect of storage media on microhardness was not significant at baseline, but significant at 48 hr and after 7 day (p = 0.001 and p < 0.001, respectively). Lactic acid had the greatest effect. CONCLUSIONS: The microhardness of composites decreased after 7 day of immersion. The microhardness of P90 was lower than that of other composites. Lactic acid caused a greater reduction in microhardness compared to other solutions.

Objectives: To evaluate the push-out bond strength of dimethacrylate (Clearfil SE Bond/Filtek Z250; and Adper SE Plus/Filtek Z250) and silorane-based (Filtek P90/Filtek P90) restorative systems following selective dentin pretreatment with a CPP-ACP-containing paste (MI Paste).

The current study investigated the effects of different polishing systems on the surface roughness and microhardness of a silorane-based resin composite. Forty disks were fabricated (o = 12 mm, h = 2.5 mm) of Filtek P90 (3 M ESPE, USA). The specimens were divided into four groups (n = 10), according to the polishing system: G1 - Mylar strip (control); G2 - Felt-disc + diamond paste, G3 - Sandpaper discs; G4 - Silicone tips. The specimens were stored in distilled water at 37°C for 24 h. The external surface roughness was determined through measuring the Ra of the specimens. The Vickers microhardness was measured using a microhardness tester. The values of surface roughness and microhardness of each specimen were statistically analyzed using one-way ANOVA, Games-Howell and Ryan-Einot-Gabriel-Welsch (REGW-Q), and setting the statistical significance at p ≤ 0.05. It was observed that G2 (0.42 μm) and G4 (0.43 μm) showed statistically significant differences when compared to groups G1 (0.25 μm) and G3 (0.19 μm) (p 0.05). The polishing systems altered the surface roughness of a silorane-based resin composite, but did not influence the microhardness values.

This study evaluated the surface roughness (Ra) of methacrylate and silorane-based composites submitted to different light-activation protocols and bleaching agents. The samples were divided into 12 groups (n=10) according to the composite (Filtek Z250 - 3M Espe, Filtek P90 - 3M Espe and Opallis - FGM); to the light-activation protocol (1000 mW/cm2 X 18 s (S) and 3200 mW/cm2 X 6 seconds (PE)); and bleaching agent (hydrogen peroxide at 6% and hydrogen peroxide at 35%). Roughness test were carried out at the following set times: initial (R1), after polishing (R2) and 24 hours after bleaching (R3). Data obtained were submitted to the statistical analysis. The results showed that higher values of Ra in R1 were obtained by Filtek P90 composite, differing significantly of the other samples, which showed similar results among them. There was significant decrease of Ra in R2 under all the conditions, except by the Opallis composite, independently on the light-activation protocol, and Filtek Z250 light-activated by PE protocol. There were no difference between R2 and R3 for all the composites and any light-activation protocol. It was possible conclude that bleaching agents did not interfere in significant way on surface roughness of the composite evaluated.

Aim : Our study aimed to analyze the microleakage of silorane-based composite in comparison to two homologous methacrylate-based composites. Materials and Methods : Standardized class I cavities (4 × 2.5 × 3 mm) were prepared on extracted human premolars and randomly assigned into three groups (N = 15) as follows: Group A, Filtek P90 (silorane) with its dedicated adhesive system (P90 system adhesive); Group B, Adper SE Plus with Filtek Z250; Group C, Peak SE with Amelogen Plus. The teeth were subjected to thermocycling regime (200×, 5-55°C) and dye penetration of tooth sections were evaluated following 30 minute immersion in 2% Methylene Blue dye. Statistical analysis was performed with Kruskal-Wallis and Mann-Whitney U test at 95% significance level. Results : Silorane exhibited significantly decreased microleakage compared with any other resin based composite (RBC). The cavities restored with Amelogen Plus displayed nonsignificantly higher microleakage than with Filtek Z250. Conclusion : Although all of the restorative systems had microleakage, silorane technology showed less microleakage comparable to clinically successful methacrylate-based composite. This will improve the clinical performance and extend the composite durability.