Roughness Of Composite Resin Research Articles

Effect of Chemical Challenges on the Properties of Composite Resins.

Objective To evaluate the chemical degradation effect on microhardness and roughness of composite resins after aging. Materials and Methods Specimens (n = 10) were used for Filtek Z350 XT (Z350), Filtek Bulk Fill (BULK), Micerium HRI (HRI), Micerium BIOFUNCION (BIO), and Vittra APS (VITTRA). Microhardness and roughness were performed before and after degradation with the followed solutions: citric acid, phosphoric acid, 75% alcohol, and distilled water. Samples were to a 180-day chemical cycling protocol. After degradation, one sample of each group was selected for scanning electron microscope evaluation. The data were analyzed with normal distribution (Kolmogorov–Smirnov) and similarities of variations for the Bartlett test. ANOVA (two-way) followed by Tukey's test was performed considering treatment and composite resin (P < 0.05). Results For microhardness and roughness, variations were noted to different solution and resin formulations. Z350 and HRI showed higher microhardness percentage loss, and it was more evident after storage in alcohol (−48.49 ± 20.16 and −25.02 ± 14.04, respectively) and citric acid (−65.05 ± 28.97 and 16.12 ± 8.35, respectively). For roughness, Z350 and VITTRA showed less delta values after alcohol storage (−0.047 ± 0.007 and −0.022 ± 0.009, respectively). HRI had the worst roughness for citric acid (−0.090 ± 0.025). All resins were not statistically different between each other in water and phosphoric acid. Conclusion The formulations of restorative resin materials influenced in degree of surface degradation after 180 days of chemical degradation. Water was considered the solution that causes less degradation for microhardness and roughness evaluations. For microhardness, alcohol was considered the worst solution for Z350 and HRI. For superficial roughness, Z350 and VITTRA showed less degradation in alcohol and citric and phosphoric acid solutions.

Surface roughness of composite resins submitted to three different finish and polish systems

Objective: This study aimed to evaluate the in vitro performance of three different finishing and polishing systems, concerning providing better surface smoothness. Materials and methods: 2x4 mm specimens were made with 6 composites: Filtek Z250, Classic Herculite, Opalis, Filtek Z350, Zirconfilll and Estelite Omega, which were subsequently divided into four groups according to a different finishing system (Sof-Lex, OptiDisc, Praxis and Control). After polishing, twelve specimens were distributed to each of the six resins studied, making a total of 72 samples (n = 3), which had their roughness evaluated by a contact roughnessmeter. The Kruskal-Wallis test and Dunn's post-test with Bonferroni adjustment were used to search for significant differences. Values ​​were considered significant when p &lt;0.05. Results: The roughness values ​​for finishing systems showed statistical differences between OpiDisc x Praxis (p = 1,000), OpiDisc and Sof-lex (p = 0.605) and Control and all systems (p &lt;0.0001). There was no statistical difference when analyzing the combination of resin x system. The Mylar strip provided surface quality. Conclusions: The size, composition and shape of the filler influenced the surface. Sof-lex and Praxis showed similar results, thus being a good choice for polishing. Clinical Relevance: This study aimed to help the professional in the choice of a better material in the polishing step.

Influence of different polishing and aging periods on the surface roughness of composite resins

The aim of this study was to evaluate the influence of the polishing period on surface roughness (Ra) before and after thermal aging in four composite resins - CR (Durafill VS, Vittra APS, Filtek Z350XT and Spectra Smart). This in vitro study evaluated: (1) CR in 4 levels; (2) polishing period (PP) in three levels (immediate, 7 and 14 days) and (3) artificial aging in two levels: without aging and after 10,000 cycles. For this, 240 CR specimens were allocated into 12 groups (n=20) according to PP with SofLex Pop On disks. For Ra, 3 measurements on the top surface of each specimen were performed with a diamond tip and constant load of 4mN and 0.25mm/s. Next, the specimens were aged in thermocycling, with temperatures of 5° and 55°C, during 30 seconds in each temperature, and repeated testing afterwards. The data were submitted to statistical tests with 5% significance. The alteration in Ra was observed only in the late polishing in the period of 7 days, where the Durafill VS CR showed higher Ra in comparison to the other CRs. After thermocycling, the groups showed significant difference only with late polishing in the 21-day period; the nanoparticulated RCs (Z350XT˂Vittra APS) recorded the highest Ra values, followed by the microhybrid (DurafillVS) and nanohybrid (Spectra Smart) RCs, respectively. Thus, late polishing in the 7-day and immediate period provided higher Ra values, especially for the nanohybrid and microhybrid composite resins.

Effect of Fluoride Gels on the Surface Roughness of Different Composite Resins

Background: The pH of fluoride gels influences the roughness of composite resins, which affects their clinical durability. Objective: To evaluate the effect of fluoride gels (1.23% acidified phosphate fluoride and neutral fluoride) on the morphology of different composite resins after finishing and polishing. Methods: We prepared sixty specimens with a diameter of 5 mm and a height of 2 mm. The specimens were then divided into six groups (n = 10), according to the type of composite resin (Z250 micro-hybrid (Z), Filtek Z350 XT nanoparticles (XT), and Tetric N-Ceram nano-hybrid (TC)) and fluoride gel treatment (1.23% acidified phosphate (APF) or neutral fluoride (NF)) to measure surface roughness (Ra). The material was light-cured using an LED-curing unit (Elipar Freelight Deep Cure-3M/ESPE) for 20 s with a light intensity of 1.200 mW/cm2. Ra measurements were performed before and after treatment with different fluoride gels using a rugosimeter (Mitutoyo SJ210). After Ra, we selected two samples from each group for evaluation using scanning electron microscopy. Data were analyzed using the Shapiro-Wilk, ANOVA, and Tukey tests, with a significance of 5%. Results: The average Ra before and after NF did not differ statistically. The average Ra values of the groups treated with APF showed statistically significant differences. The photomicrographs of the groups treated with NF were similar to those of the groups without fluoride treatment. The APF-treated groups showed significant morphological changes. Conclusion: NF did not promote changes in the morphology of the evaluated composite resins, in contrast to APF, which caused significant changes.

A COMPARATIVE STUDY ON SURFACE CHANGES BETWEEN COMPOSITE VENEER AND ACRYLIC RESIN USING BATTERY- OPERATED TOOTHBRUSH AND MANUAL TOOTHBRUSH

Early forms of toothbrush have been in existence since 3000 BC. Several changes have happened since then, it has evolved from a‘chew stick’, into a bristle toothbrush, then a battery-operated toothbrush. Tooth brushing has been our primary way of cleaning theoral cavity and its structures to maintain good oral hygiene. However, prolonged brushing can be abrasive to one’s existing restorationand prosthesis increasing the surface roughness, leaving the resins vulnerable to damage and plaque accumulation. This study aims toevaluate the effect of tooth brushing using a manual toothbrush and a battery-operated toothbrush to the surface roughness ofcomposite resin restorations and denture base acrylic resin. Composite specimens and denture base acrylic specimens showed varyingwear and surface roughness with several variables taken into consideration such as brushing force, brushing stroke, dentifrice, type ofbristle, and type of toothbrush used. The expected result is that the specimens brushed using the battery-operated toothbrush withapplied toothpaste will have greater wear and surface roughness.

Effect of erosion and methods for its control on the surface roughness of composite resin

Objective: This study evaluated the surface roughness of a nanofilled composite resin submitted to different degrees of erosion and methods of control.Methods: 120 cylindrical composite specimens (6×1.5 mm) were randomly divided into four groups, according to the surface protection against the erosive challenge [negative control, topical application of fluoride, glass-ionomer sealant, resin sealant]. After the application of the respective method, specimens were divided into three subgroups (n=10): a) absence of erosive challenge; b) 9 cycles of DES-RE; c) 18 cycles of DES-RE. Surface roughness (Ra, μm) was recorded and statistically analyzed (2-way Anova/Tukey).Results: The glass-ionomer sealant exhibited less rough surfaces under all the conditions. However, the average roughness was significantly higher after 18 DES-RE cycles.Conclusion: Despite the potential shown by glass-ionomer sealant, it was concluded that no material prevented an increase in surface roughness of the nanofilled composite after an intense erosive challenge.

INFLUÊNCIA DOS ENXAGUATÓRIOS BUCAIS NA RUGOSIDADE SUPERFICIAL DE UMA RESINA COMPOSTA

Surface smoothness is an important feature of restorative material. Thus, composite roughness levels should be low to make retention of dental biofilm. Alterations of the surface of composite resin restorations can be associated to drinks and acidic foods, components of saliva, finishing and polishing methods, as well as the action of bleaching agents, rinses and fluoride. Purpose: To evaluate the effect of mouth rinses in superficial roughness of composite resin through a quantitative evaluation. Methods: 48 specimens with composite resin FiltekTM Z350 XT were made and divided into 4 groups (n=12): distilled water, Colgate® Plax, Oral B® and Listerine®. Specimens were made using a rectangular matrix with holes, each measuring 0.8 cm of internal diameter and 0.2 cm in thickness. The specimens were immersed in 50 ml of each substance, for 12 hours, to simulate a year of daily use of the solution for 2 minutes. Then specimens were stored in distilled water until reading of the roughness tester. Data were statistically treated by ANOVA and Tukey tests, with a significance level of 95%. Results: No statistically significant difference was observed between the control group and Listerine® (p = 0.03). When comparing the average roughness of different brands of mouthwashes, there was no statistically significant difference (p &gt; 0.05). Conclusions: Among the mouthwashes tested, only Listerine® caused statistically significant increase in superficial roughness of the composite resin used.

Influence of Finishing and Polishing Techniques and Abrasion on Transmittance and Roughness of Composite Resins.

The aim of this study was to evaluate the influence of finishing and polishing systems and toothbrush abrasion on transmittance (T) and surface roughness (Ra) of three composite resins (Filtek Z350 XT, Tetric N-Ceram, and IPS Empress Direct). Eighteen resin disks (10 mm diameter × 2 mm thick) finished by polyester strips had initial surface smoothness recorded, representing phase 1 (P1). Specimens were divided into three groups (n=6) according to the finishing/polishing instrument used (OneGloss, TopGloss, and Sof-Lex) to compose phase 2 samples (P2). Then specimens were subjected to 514 cycles of toothbrush simulation using a toothpaste slurry, with a constant load applied to soft bristles, and were then washed (phase 3=P3). After each phase, the specimens were examined by an optical profiler and spectrophotometer to measure Ra and T. Data were analyzed by analysis of variance, Tukey and Pearson tests. T values were statistically influenced by composite resin ( p=0.000) and phase of measurement ( p=0.000) factors, while the finishing/polishing system used ( p=0.741) did not affect T. On the other hand, Ra values were statistically affected by the factor finishing/polishing system ( p=0.000), but not by composite resin ( p=0.100) and phase of measurement ( p=0.451). Tetric N-Ceram and Empress Direct presented higher values of roughness when polished by OneGloss, while TopGloss and Sof-Lex showed a lower roughness. It can be concluded that composite resins transmitted more light after dental abrasion. Transmittance of composite resins was not modified by the distinct roughness created by finishing/polishing instruments.

Effect of finishing and polishing on surface roughness of composite resins after bleaching

Aim: To evaluate the influence of finishing and polishing techniques on the surface roughness of two composite resins (CRs) subjected to bleaching procedure. Methods: Forty-eight CR specimens were divided into six groups (n=8). For G1 to G3, a microhybrid CR (Opallis; FGM) was used, and G4 to G6, received a nanohybrid CR (Brilliant NewLine; Coltene/Whaledent). All specimens were subjected to bleaching procedure with 35% hydrogen peroxide (two 45-min applications, with a 5-day interval). The surface roughness of all specimens was evaluated before and after the bleaching and/or finishing/polishing (Ra parameter) by a roughness meter. After bleaching, the groups were subjected to finishing and polishing procedures: G2 and G5 - felt discs + diamond pastes; and G3 and G6 - silicon rubber tips. The control groups (G1 and G4) had no finishing or polishing treatment after bleaching. Data were analyzed by ANOVA and Tukey’s posttest, and t test for paired samples (α=0.05). Results: bleaching treatment increased Ra values for the nanohybrid CR specimens, but both finishing/polishing techniques were able to reduce these values; for the microhybrid specimens, only finishing/polishing with silicon rubber tips decreased the roughness values. Conclusions: For both microhybrid and nanohybrid CRs, the silicon rubber tips were effective to reduce the surface roughness after bleaching procedure.

支台築造用コンポジットレジンの切削に関する基礎的検討

Filler contents, Knoop hardness, characteristics of cutting and surface texture of eight commercial composite resin cores were investigated. Two posterior composite resins and two silver alloys were used as controls. No differences were found in filler contents and Knoop hardness between the composite resin cores and posterior composite resins. In the composite resins, Knoop hardness was correlated to the filler content. The characteristics of cutting with a diamond point varied largely among materials. The composite resin cores were divided by deterioration of the characteristics of cutting into two groups. The degree of surface roughness of composite resins polished with a finishing diamond point was larger than that of the silver alloys. SEM examination revealed little differences in the composite resin surfaces cut with a diamond point but large differences in surfaces polished with a finishing diamond.

Surface roughness of composite resins before and after finishing.

The surface roughness before and after polishing with sand paper discs, cuttlefish discs, and aqueous suspensions of pumice was studied on 6 composite resins (Adaptic ®, Addent 12 ®, Blendant®, Dakor®, D.F.R.® and TD 71®) and two reference materials (Sevriton Simplified® and Biotrey®), with an apparatus, type Perth-O-Meter S4 BD Lowener, where mechanical registrations of the surface profiles were made. The sources of variance used were operators (2), strips (2), test pieces (2), materials (8) and surface treatments (4).The results, as given by the CLA- and RMAX-values of the studied surfaces, indicate that the brands of composite resins investigated differed in surface roughness both directly after setting and after the three different types of surface grinding used. The main finding, however, was that no type of grinding could produce as plane surfaces as that found after the resins had set under strips.When the composite resins as a group were compared with a silicate cement they seemed to have smoother...