Composite Resin Surfaces Research Articles

The Different Polishing Systems Effect on Ormocer and Supranano Spherical Filler Composite Resin Surface Roughness

Background: The polishing procedure is an essential step in composite resin restoration. There are two types of polishing systems, which are one-step and multi-step polishing systems. Purpose: This study aimed to identify the effect of different polishing systems on the surface roughness of ormocer and supranano spherical filler composite resin. Material and Methods: This study was conducted in an experimental laboratory. The specimens were ormocer and supranano spherical filler composite resin filled in a cylindric metal mold. The total of specimens was thirty-two (n=32) of each composite resin. Each composite resin specimen was divided into four groups, then polished using PoGo (group 1 – one-step polishing system), Optrapol (group 2 – one-step polishing system), Sof-lex (group 3 – multistep polishing system), and Optidisc (group 4 – multistep polishing system). Specimens were incubated at 37℃ for 24 hours. Subsequently, specimens were assessed with a stylus profilometer surfcorder SE 1700. Data were analyzed using an independent t-test and one-way ANOVA. Result: There was a significant difference in surface roughness of the one-step and multistep groups (p ≤ 0.05). The lowest surface roughness value was in the Sof-Lex disc group (0.4026μm), and the highest surface roughness was in the PoGo group (1.1036μm). Conclusion: Based on composite resin, supranano spherical filler had less surface roughness than ormocer (p ≤ 0.05). Furthermore, both ormocer and supranano spherical filler polished using a multistep polishing system had lower surface roughness than those polished using a one-step polishing system.

Impact of the occlusal contact pattern and occlusal adjustment on the wear and stability of crowns

ObjectivesTo investigate the impact of the occlusal contact situation and occlusal adjustment on wear, roughness, and fracture force of molar crowns. Materials and methodsCAD/CAM crowns (lower right first molar, n = 64; 4 groups à 8, 3Y-TZP zirconia and resin composite) and corresponding antagonists (upper right first molar; 3Y-TZP zirconia) were manufactured. Crowns were constructed according to two principles of occlusion (group “T”: Peter K. Thomas’ “point-centric” cusp-to-fossa tripodization concept, with 15 contact points; group ”RA” Sigurd P. Ramfjord and Major M. Ash, “freedom in centric” concept with four contacts). On one half of the crowns, occlusal adjustment was performed (groups “T adjusted” and “RA adjusted”). All crowns underwent combined thermal cycling (TC) and mechanical loading (ML) (ML: 1.2 × 106 cycles, 50 N, 2 Hz, mouth opening 1 mm; TC: 2 × 3000 cycles, 5/55°C). Wear area and depth of each contact point on the occlusal surfaces of crowns and antagonists were determined using a digital microscope. Surface roughness (Ra, Rz) was measured in and besides (reference) the worn area (3D laser-scanning microscope). Fracture force of the crowns was determined (statistics: Levene-test, one-way-ANOVA; Bonferroni-post-hoc-test; between-subjects effects, Pearson correlation, α=0.05). ResultsThe resin composite crowns yielded significantly higher mean values for wear area and depth (p < 0.001) and lower fracture forces (p < 0.001). Resin composite surfaces showed increased roughness after TCML while zirconia exhibited smoothened surfaces. The occlusal design significantly impacted wear depth (p = 0.012) and fracture force (p < 0.001). Resin composite crowns with fewer contact points (group RA) showed more wear and lower fracture force. Adjusted resin composite crowns showed increased wear areas and depths (p = 0.009-0.013). For zirconia crowns, the adjustment impacted wear area (p = 0.013), wear depth (p = 0.008), and fracture force (p = 0.006), with adjusted zirconia crowns exhibiting more wear and lower maximum forces until fracture. Zirconia wear depth was also impacted by the occlusal design (p = 0.012). Antagonistic wear was influenced by the restorative material, the occlusal contact pattern, and the adjustment. ConclusionsThe investigated materials show strongly varying performances with zirconia being significantly influenced by the adjustment, while for resin composites, contact design and adjustment had a major impact. Clinical relevanceThe results show the necessity of adapting occlusal design and adjustment in order to improve roughness, wear, and stability of zirconia and resin composite crowns.

In Vitro Evaluation of Gastric Acid and Toothbrushing Effect on the Surface State of Different Types of Composite Resins.

Background and Objectives: The aim of this in vitro study was to evaluate the effect of gastric acid associated with the effect of toothbrushing on the surface roughness of different types of composite resin used for direct restorations. Materials and Methods: The materials used in this study were two microhybrid (Filtek Z250, Herculite XRV) and two nanohybrid (Filtek Z550, Herculite XRV Ultra) composite resins. Two hundred and forty cylindrical samples with a height of 2 mm and a diameter of 6 mm were divided into four groups (groups A, B, C and D) corresponding to each tested material (n = 60). Each group was divided in two subgroups: subgroup I—the samples were submersed in hydrochloric acid and immediately submitted to toothbrushing; subgroup II—the samples were submitted only to toothbrushing. The simulation of the acid attack was performed by immersing the samples in a 0.01 M hydrochloric acid solution for 90 min. This procedure was followed immediately by toothbrushing simulation with 10,000 cycles. The acid attack and toothbrushing simulation were performed for two times. The surface roughness evaluation was performed with a Proscan 2100 profilometer. Repeated Measures ANOVA and Bonferroni post-hoc tests were used to perform the statistical analysis. Results: Simulation of one year of toothbrushing associated or not to hydrochloric acid exposure increases the surface roughness of microhybrid and nanohybrid composite resins. Six months of toothbrushing associated to six months of hydrochloric acid exposure increase the surface roughness of nanohybrid composite resins. Conclusions: Microhybrid composite resins surface becomes rougher after toothbrush and acid submersion when comparing to nanohybrid composite resins.

Comparison of the shear bond strength between metal brackets and Transbond™ XT, Filtek™ Z250 and Filtek™ Z350 before and after gastroesophageal reflux: An in vitro study

To evaluate in vitro the effect of gastroesophageal reflux, before and after bonding of metal brackets on composite resin surface. Two hundred and ten resin discs were divided into 5 groups (n=42), according to the time and medium of storage: 24h, 7- and -30 days in artificial saliva (AS) and hydrochloric acid (HCL). Twelve samples from each group were submitted to surface roughness analysis (n=60). The other one hundred and fifty samples were divided into 3 groups (n=50) according to the bonding material: Transbond™ XT (TXT), 3M™ Filtek™ Z250 (Z250) and 3M™ Filtek™ Z350 XT (Z350). After bonding, the samples were subdivided, one more time, into 5 groups (n=10) according to the time (24h, 7, and 30 days) and medium storage (AS, HCL). Following, the shear bond strength (SBS) analysis was accomplished. Erosive challenge was performed for 7 or 30 days, before and after bonding of orthodontic brackets, for 1min, 4 times a day. SBS was performed in a universal testing machine (Instron) at 0.5mm/min. SBS data were subjected to two-way ANOVA and Tukey's test (α=0.05). TXT showed higher SBS values in all conditions (AS-10.9±2.0 (24h); 10.5±4.9 (7 days); 9.4±2.2 (30 days); HCL-11.5±3.7 (7 days); 8.0±2.1 (30 days))-(P<0.0001). No statistical difference was detected in SBS between Z250 and Z350 composite resins (Z250 SBS: AS-7.1±1.9 (24h), 5.2±1.8 (7 days), 4.5±1.5 (30 days); HCL-5.2±2.3 (7 days), 5.0±2.5 (30 days))-(P<=0.063)/Z350 SBS: AS - 7.4±1.0 (24h); 3.7±1.7 (7 days); 3.4±1.7 (30 days); HCL-3.5±3.3 (7 days); 4.4±1.2 (30 days))-(P<=0.167), respectively). Storage times and media did not statistically influence the SBS of TXT and Z250 composite resins (P>0.05), but did influence the Z350 SBS (P<0.05). Regardless of time and storage medium, TXT was the best composite resin for bonding brackets. Furthermore, the erosive challenge did not lead to surface changes in the Z250 resin at 7 and 30 days, unlike the Z350 resin.

Effect of Pineapple Juice (Ananas comosus) on Surface Roughness of Preheated and Non-Preheated Nanohybrid Composite Resins

&#x0D; Introduction: Nanohybrid composite resins is a type of composite consisting 2 different filler sizes, where one filler ranges in nanoparticles 0.01-0.05µm. Pineapple juice (Ananas comosus) is a widely consumed drink by Indonesian with pH range 3.5-4.6. Surface roughness may be affected by extrinsic factors such as low pH from pineapple juice. Rough surface can cause bacterial adhesion and plaque accumulation on restorative material which cause secondary caries, gingivitis and staining. Preheating is a preparation method of composite which improve composite physical and mechanical properties.&#x0D; Objective: To analyze the difference in surface roughness of preheated and non-preheated nanohybrid composite resins after immersion in pineapple juice.&#x0D; Methods: This research was a laboratory experimental with post-test and control group design. Thirty-three cylindrical sample of nanohybrid composite resin Filtek Z250 XT A2 shade (3M ESPE) (10 mm x 2 mm) were divided into 3 groups: Preheated, Non-preheated and control. Preheated and non-preheated group were immersed in 10 mL pineapple juice for 2 hours for 12 days, control group were immersed in 10 mL distilled water for 24 hours for 12 days. Surface roughness was measured after immersion using surface roughness tester Taylor Hobson, Subtonic S-100 Series-S128) and analyzed using one way ANOVA followed by Post Hoc Tukey.&#x0D; Results: Statistical analyze with one way ANOVA test indicates significant differences between surface roughness in 3 groups with p = 0.034, average surface roughness of pre-heated group was calculated in 0.73 µm, non-preheated group in 0.81 µm and control group in 0.55µm. Tukey’s Post hoc with p = 0.03 shows significant difference in surface of non-preheated composite resin with control group.&#x0D; Conclusion: Pineapple juice increases surface roughness of nanohybrid composite resins after 2 hours immersion for 12 days in comparison with control group.

Effect of Wet and Dry Polishing Conditions by Two Finishing and Polishing Systems on the Surface Roughness and Color Changes of Two Composite Resin Restoratives: An In Vitro Comparative Study

Purpose: The study aimed at evaluating the effect of wet and dry polishing systems on the resin composites’ surface roughness and color change. Materials and Methods: In the study, samples were prepared using nanoceramic (Ceram.x one) and nanohybrid (GrandioSO) resin composites. Two different finishing and polishing systems were used in the polishing of resin composites. Resin composite surfaces were finished and polished under wet and dry conditions. The initial surface roughness values (Ra) of the samples were measured using a profilometer, whereas the color changes were measured using a spectrophotometer. Then, the colors of the samples kept in coffee were measured on the 7th and 30th days. Surface roughness and color change values (ΔE00) were measured and statistically analyzed using the one-way analysis of variance (ANOVA) test ( P &lt; .05). Results: Wet or dry use of polishing systems did not show a statistically significant difference between the surface roughness values of the resin composite ( P &lt; .05). Wet and dry use of polishing systems showed similar color changes on the composite resins ( P &lt; .05). Diamond-containing spirals on composite resins showed statistically less color change than aluminum-oxide-containing discs ( P &lt; .05). Wet or dry use of polishing systems did not reduce the color change of the composite resins below the acceptability threshold (AT). Conclusion: Wet or dry use of polishing systems on composite resins did not affect surface roughness and color change. The use of diamond-containing polishing spirals that cause less color change can increase clinical success.

Effect of Liquefied Digestive Medicine on the Surface of Composite Resin

Effect of Liquefied Digestive Medicine on the Surface of Composite Resin

Effect of immediate and delayed finishing and polishing procedure on Streptococcal mutans adhesion and micro-hardness of composite resin surface: An in-vitro study

Proper finishing and polishing have become the indispensable step in clinical restorative dentistry due to increased aesthetic demands. There are several polishing systems containing fine particle size abrasives. The adhesion of bacterial plaque to restoration depends on the surface properties and composition of materials. In literature, surface roughness after polishing is well documented, but the timing, i.e., immediate or delayed polishing affecting the bacterial adherence and microhardness on the composite needs research. As the Streptococcus mutans has a major role in primary and secondary caries, so in this light, this study is conducted to investigate the best timing of polishing affecting the bacterial adhesion and microhardness of composite resin.: To evaluate the Streptococcal mutans adhesion and microhardness of composite resin after polishing them, immediately and after 24 hours of curing.: Sixty specimens were made from composite resin Filtek Z 350 XT (3M ESPE) of 6mm diameter and 4mm height, was cured by placing a Mylar strip and divided into 3 groups- Group 1 the control group with only MYLAR-STRIP, Group 2- Polishing system SOF-LEX (3M ESPE Dental products St. Paul, MN,USA.) Group 3- Polishing with SUPER-SNAP (Shofu Inc., Kyoto, Japan). Group 2 and 3 were further divided into two subgroups according to the polishing time- immediate and delayed. The Streptococcal mutans adhesion for each group was measured by colony forming units and compared. The mean log of CFU/mL present in the biofilm was also calculated. The results of bacterial adherence was analysed by three-way ANOVA (analysis of variance) (p&amp;#60;0.01) and the ANOVA two-way of variance was used for checking microhardness (p&amp;#60;0.01). A p value &amp;#60;0.01 was considered to indicate a statistically significant for both bacterial adhesion and hardness. Polishing after 24 hours of curing showed less bacterial adherence on the composite surface, regardless of the polishing treatment performed(p&amp;#60;0.01). Polishing with SOF-LEX(Group-2) had the lower bacterial adherence than SUPER-SNAP (Group-3), Control group (Mylar matrix strip) promoted the lowest bacterial adhesion on the surface composites. Micro hardness of composite was lowest in Mylar matrix group. Immediate polishing procedure showed lower microhardness values as compared to polishing that was delayed for 24hours for both polishing groups. SOF-LEX system can be used for chairside polishing of composite restorations in clinic and delayed finishing and polishing of composite shows better surface microhardness values.

Effect of oral irrigation device and its solution type on the surface roughness and topography of Bulk-fill composite resins.

BackgroundSurface roughness and topography of composite resin materials have a significant role in biofilm aggregation, periodontitis, and recurrent caries. The present study evaluated the effect of the Waterpik oral irrigation device (OID) with different solution [water/ chlorhexidine (CHX)] on the surface roughness and topography of microhybrid (x-tra fil) and nanohybrid (Tetric N-Ceram Bulk) bulk-fill composite resins. Material and MethodsDisk-shaped samples were prepared from each composite resin, measuring 5 mm in diameter and 3 mm in height, and assigned to three groups in terms of treatment (n=19): group A, control (storage in distilled water); group B, OID with water; group C, OID with 0.5% CHX. The samples were treated for eight weeks, simulating one-year use of OID. Profilometry and scanning electron microscopy (SEM) were used to evaluate and compare quantitatively surface roughness (Ra) and qualitative topography of composite resin surfaces before and after treatment. The data were analyzed with paired-samples, Wilcoxon, and generalized estimating equations tests (α=0.05). ResultsThe application of OID increased the Ra of composite resin compared to the control group (P<0.001). No significant difference was detected between the two solutions (water and CHX) (P=0.615). The effect of composite resin type and the cumulative effect of composite resin type and OID solution were not significant on the surface roughness changes of the samples (P=0.243 and P=0.464, respectively). ConclusionsOID with water and CHX solutions increased the surface roughness and topographic changes of microhybrid and nanohybrid bulk-fill composite resins. Key words:Composite resins, irrigation, mouthrinse, surface roughness, topography.

Effect of fermented milk product on composite resin surface

Effect of fermented milk product on composite resin surface

Effect of Interval Time between Corrosive and Abrasive Challenges on a Nanoparticulate Composite Resin.

Objective This study aimed to evaluate the effect of interval time after acidic beverage intake and brushing on roughness and hardness of resin composite. Materials and Methods Nanofilled resin composites were tested as per interval time (no interval, 15 or 30 minutes) between aging media (isotonic, sports drink) and brushing. Specimens ( n = 9) were subjected to three cycles daily for 5 days with immersion in beverage followed by simulated brushing (585 strokes). The brushing (control) group was submitted only in brushing cycles. Roughness and microhardness were analyzed in the baseline and end of the experiment. Surface morphology was analyzed by using scanning electron microscopy (SEM). Statistical analysis Data were analyzed by one-way ANOVA and Tukey’s honestly significant difference (α = 0.05). Results Roughness was higher in no interval group and lower in 30 minutes and control. The 15 minutes present no statistical difference between control, 30 minutes and no interval. The hardness not present difference between groups. The SEM showed the no interval more roughness than 15 and 30 minutes, control and baseline. Conclusion The interval time between erosive and abrasive challenge is important to preserve the smoothness surface of composite resin.

Influence of surface treatment of resin composite substrate on the load-bearing capacity under fatigue of lithium disilicate monolithic simplified restorations

This study evaluated the influence of surface treatments of resin composite substrate on the fatigue behavior of adhesively cemented lithium disilicate glass-ceramic simplified restorations. CAD/CAM lithium disilicate ceramic blocks were shaped into discs (N = 60, Ø = 10 mm; thickness = 1.0 mm). Resin composite discs (N = 60, Ø = 10 mm, thickness = 2 mm) were allocated into four groups considering the “surface treatment” factor: Ctrl – no surface treatment; Bur – grinding with coarse diamond bur (#3101G, KG Sorensen); PA – etching with 37% phosphoric acid (15 s); AA – air abrasion with alumina particles (45 μm, 10 mm distance, 2.8 bars, 10 s). The surface topography, the roughness, the fractal dimension (estimated by the box-counting method) and the contact angle analyses were performed after the surface treatments. The lithium disilicate discs were etched (5% hydrofluoric acid, 20 s), silanized and adhesively cemented (Multilink N, Ivoclar Vivadent) on the resin composite discs. The samples (bonded restoration set) were subjected to a step-stress fatigue test at 20 Hz, 10,000 cycles/step with a step-size of 100 N applied on the ceramic surface, having ceramic up and resin composite down. Fractographic analysis was performed. The fatigue data (Fatigue Failure Load – FFL; and Cycles for Failure – CFF) were analyzed by Kaplan Meier with Mantel-Cox log-rank post-hoc tests (α = 0.05). No statistical difference for fatigue performance could be found among the groups (FFL means: 820–867 N; CFF means: 53,195–61,090 cycles). The bur group showed higher surface roughness and contact angle values. The PA group has the highest average fractal dimension. Therefore, the resin composite surface treatment induces topographical changes, however, it has no effect on the fatigue behavior of lithium disilicate restorations.

“Effect of three vitamin antioxidants on reversal of shear bond strength of bleached enamel: An in-vitro Study.”

ABSTRACT&#x0D; Aims and objectives: To evaluate the effect of Sodium ascorbate, Alpha-tocoferol and Beta-carotene vitamins antioxidant on reversing the bond strength between resin composite and bleached enamel surface.&#x0D; Materials and methods: The study focussed on use of three vitamin antioxidants. All the groups in the study were subjected to bleaching containing 35% Hydrogen peroxide. Resin restoration were done after 1 week and immediately after bleaching without any antioxidant in Group 1 and 2 respectively. While in Group 3, 4 and 5, following bleaching treatment, samples were exposed to Beta-carotene gel, Sodium Ascorbate solution and Alpha-tocoferol gel respectively for 10 minutes, before resin restoration was done. Specimens were then subjected to Universal Testing Machine. The results were statistically analysed using ANOVA test and Tukey Honest Significant Difference (HSD) test, to comparatively analyse statistical differences between the groups.&#x0D; Results: The mean shear bond strength values of Group 4 (Sodium Ascorbate solution) showed significantly high bond strengths than Groups 3 (Beta-carotene gel) and 5 (Alpha-tocoferol gel).&#x0D; Conclusion: Treatment of bleached enamel with Sodium ascorbate and Alpha tocoferol antioxidants has significantly improved the shear bond strength of composite resin to enamel.&#x0D; Keywords: alpha-Tocopherol, Antioxidants, Ascorbic Acid, beta Carotene

Influence of different antioxidant agents on the microtensile bond strength of restored teeth after bleaching

Introduction Due to an increase in patient awareness and search for aesthetic treatments, dental bleaching is a frequent and safe procedure in clinical practice for the removal of stains [1]. Bleaching agents are known to adversely affect the bond strength between resin composite and tooth surface, when adhesive procedures are performed immediately after tooth bleaching [2]. The reduction in bond strength is related to the presence of residual oxygen, a sub product of hydrogen peroxide that remains on the tooth surface and which may interfere with infiltration of the resin in the dentine tubules and inhibit the polymerisation of resin monomers [3]. Antioxidant agents like sodium ascorbate, grape seed extract and green tea may be used as an alternative to delay the restorative procedure due to their potential as reversers of these adverse effects [2]. This study aims to assess the influence of different antioxidant agents on the bond strength of restored bleached teeth. Materials and methods The present study was approved by the Ethics Committee of Instituto Universitário Egas Moniz. Fifteen human permanent molars were sectioned into identical halves that were randomly distributed between five groups (n = 6): unbleached control group (CG), bleaching + resin composite bonded immediately (G1), bleaching + sodium ascorbate (G2), bleaching + grape seed extract (G3) and bleaching + green tea (G4). G1, G2, G3 and G4 were bleached for 4 h/day for a 7-day period. After bleaching, G1 samples were immediately restored with an adhesive system and a resin composite, in G2 samples a 10% sodium ascorbate gel was applied, in G3 a 5% grape seed extract and in G4 a 5% green tea, all applied for 15 min. After these antioxidants, G2, G3 and G4 were immediately restored. After 24 h, samples were sectioned in order to obtain 1.0 (± 0.3) mm2 microspecimens. The microspecimens were tested in a universal testing machine at a speed of 0.5 mm/min. Data were analysed by using a two-way ANOVA, at a significance level of 5%. Results G1 group (bleaching only) recorded the lowest mean bond strength value (9.5 (± 1.2) MPa) and it was significantly lower than the control group (CG) (19.3 (± 2.7) MPa) (p = .001). Groups in which sodium ascorbate (G2) (19.2 (± 1.3) MPa), grape seed extract (G3) (16.5 (± 0.8) MPa) and green tea (G4) (16.7 (± 2.0) MPa) were applied presented significantly higher bond strength values when compared to bleaching only (G1) (p < .001). When comparing the antioxidant agents, G2 (10% sodium ascorbate) exhibited significantly higher mean bond strength values when compared to G3 (5% grape seed extract) (p = .016). Discussion and conclusions Treatment of the enamel surface with antioxidant agents such as sodium ascorbate, grape seed extract and green tea following the bleaching procedure and immediately before the restorative procedure can reverse the compromised bond strength. These alternative strategies are effective and may be used instead of delaying the procedure.

Effect of Varying Working Distances between Sandblasting Device and Composite Substrate Surface on the Repair Bond Strength.

This study investigates the effect of defined working distances between the tip of a sandblasting device and a resin composite surface on the composite–composite repair bond strength. Resin composite specimens (Ceram.x Spectra ST (HV); Dentsply Sirona, Konstanz, Germany) were aged by thermal cycling (5000 cycles, 5–55 °C) and one week of water storage. Mechanical surface conditioning of the substrate surfaces was performed by sandblasting with aluminum oxide particles (50 µm, 3 bar, 10 s) from varying working distances of 1, 5, 10, and 15 mm. Specimens were then silanized and restored by application of an adhesive system and repair composite material (Ceram.x Spectra ST (HV)). In the negative control group, no mechanical surface pretreatment or silanization was performed. Directly applied inherent increments served as the positive control group (n = 8). After thermal cycling of all groups, microtensile repair bond strength was assessed, and surfaces were additionally characterized using scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDX). The negative control group reached the significantly lowest microtensile bond strength of all groups. No significant differences in repair bond strength were observed within the groups with varying sandblasting distances. Composite surfaces sandblasted from a distance of 1 mm or 5 mm showed no difference in repair bond strength compared to the positive control group, whereas distances of 10 or 15 mm revealed significantly higher repair bond strengths than the inherent incremental bond strength (positive control group). In conclusion, all sandblasted test groups achieved similar or higher repair bond strength than the inherent incremental bond strength, indicating that irrespective of the employed working distance between the sandblasting device and the composite substrate surface, repair restorations can be successfully performed.

Surface Integrity of Dimethacrylate Composite Resins with Low Shrinkage Comonomers.

The goal of current research was to investigate the influence of adding low shrinkage “Phene” like comonomers hexaethylene glycol bis(carbamate-isoproply-α-methylstyrene) (HE-Phene) and triethylene glycol bis(carbamate-isoproply-α-methylstyrene) (TE-Phene) on the surface and color characteristics of composite resin. A range of weight fractions (0, 10, 20, 30, 40 wt.%) of HE/TE-Phene monomers were mixed with bisphenol A glycidyl methacrylate (GMA)/triethylene glycol dimethacrylate (TEGDMA) monomer. Experimental composite resins were made by mixing 71 wt.% of silica fillers to 29 wt.% of the resin matrix. A Vickers indenter and glossmeter were used for testing surface hardness (SH) and gloss (SG) at 60°. A chewing-simulator was used to evaluate the surface wear after 15,000 cycles. Color change (∆E) and translucency parameter (TP) were measured using a spectrophotometer. Data showed that HE/TE-Phene monomer had no negative impact (p > 0.05) on surface gloss, wear, color change and translucency of experimental composite resins. Surface hardness was in a reducing direction with the increas in HE/TE-Phene weight fraction (p < 0.05). The study results suggested that incorporating HE/TE-Phene monomers up to 30 wt.% with Bis-GMA/TEGDMA resin did not negatively influence the surface integrity of composite resins except for SH.

Evaluation of three methods of surface treatment for bonding orthodontic metal brackets to resin composite in vitro

Objective: The aim of this study is to compare shear bond strength of orthodontic stainless steel brackets to resin composite surfaces In vitro using three different methods of surface treatment. Materials and methods: 60 composite resin discs, 6 mm in diameter and 2 mm in height, were prepared and aged by immersion in water for 4 weeks. After ageing, the specimens were randomly assigned to one of the following groups: (1) Control with no surface treatment, (2) 99 per cent Acetone, (3) methyl methacrylate monomer, (4) Diamond bur. The metal brackets were bonded to composite surfaces by means of an orthodontic adhesive. All specimens were stored in water for 1 week. Shear Bond Strength values were tested using a universal testing machine at a crosshead speed of 1 mm/minute, the brackets bases and corresponding RC discs were examined under stereomicroscope at 10X magnification for adhesive remnant evaluation. Shear bond strength values were analyzed using 1-way analysis of variance (ANOVA)), Adhesive remnant index scores were analysed using Chi-square test using Monte Carlo correction. Significance of the obtained results was judged at the 5% level (P ≤ 0.05). Results: The results of 1-way ANOVA for SBS means showed no statistical significant difference among the 4 groups (P = 0.564). The result of Chi-square test for ARI scores between the four groups showed a statistically significant difference (MCp = 0.039). Chi square comparisons of ARI scores showed statistically significant difference only between group 1 (control) with groups 3 (P1= 0.003) and group 4 (P1= 0.046)

Gingival epithelium attachment to well- or partially cured resin composites.

Ideal restoration material for caries would allow attachment of gingival epithelia. The attachment of epithelial cells to specimens of the 4 most commercially used well- or partially-cured resin composites, with and without TEGDMA, was assessed. Effects of resin composite on the Ca9-22 gingival epithelial cell-line were assessed by measuring the cytotoxicity, viability and gene expression for attachment, apoptosis, ROS-production, pro-inflammatory cytokines, and matrix metalloproteinases. As controls, cells on tissue culture plastic or bovine tooth enamel specimens were used. Significantly less cell attachment was measured on freshly made resin-composite specimens. Concomitantly, significantly higher cytotoxicity was measured in the presence of freshly made resin-composite specimens. However, after 8 d of leakage, the cell attachment to and cytotoxicity of the resin composite was comparable to bovine tooth enamel. Significantly higher expressions of IL6, MMP2, BCL6 and ITGA4 were measured in cells attached to resin-composite surfaces than controls. There were no significant differences between the results using different conditions of resin composite, with or without TEGDMA and well or partially cured. Less cell attachment and presence of more inflammatory markers were observed on all freshly-made resin-composite surfaces. However, after a leakage period attachment of cells to the resin composite improved to the level of natural tooth materials such as enamel. This indicated that the negative effects of resin composites on epithelial cells might be transient.

THE EFFECT OF Musa acuminata AND Ocimum basilicum MIXED EXTRACTS TO THE SURFACE HARDNESS OF BIOACTIVE COMPOSITE RESIN

ABSTRACTBackgrounds: The use of mouthwash daily may influence the mechanical properties of bioactive composite resin as a dental restoration, one of the mechanical properties is surface hardness. Herbal mouthwash can be used to minimize the side effect of mouthwash that contain alcohol. Mauli banana stem and basil leaf extracts can be produced into herbal mouthwash. Methods: Thirty specimens (10mm diameter x 2mm thick; n=5/group) bioactive composite resins were immersed in a mixed solution of Mauli banana and basil leaf extracts with concentration of 25%, 50%, 75 %%, 100%, the control group of chlorhexidine gluconate 0.2% and aquadest for 7 days in 37oC. Measurement of the surface hardness was using the Vickers Microhardness Tester with 100 gf load for 15 seconds. Results: One Way ANOVA and Post Hoc Bonferroni exhibited the significant differences (p &lt;0.05) in hardness values between the specimens that immersed in the mixed solution Mauli banana and Basil leaf extracts, which in the concentration of 100% (4,49 ± 4,61 VHN) compared with 25% (38,20 ± 2,58 VHN), 50% (41,40 ± 3,84 VHN) and 75% concentration (40,40 ± 3,55 VHN). There was no siginificant difference (p &gt;0.05) between specimens immersed in CHX, aquadest and the mixed solution of mauli banana and basil leaf extracts in all concentration. Conclusion: There is no change in bioactive composite resin surface hardness after immersed in the mixed solution of Mauli Banana stem (Musa acuminata) and Basil leaf (Ocimum basilicum) extracts.Keywords: Basil leaf extract, Bioactive resin, Mauli Banana stem extract, Surface hardness

Chemical and Mechanical Roughening Treatments of a Supra-Nano Composite Resin Surface: SEM and Topographic Analysis

Background: Repairing a restoration is a more advantageous and less invasive alternative to its total makeover. The aim of this study was to analyze the effects of chemical and mechanical surface treatments aimed at increasing the roughness of a supra-nano composite resin. Methods: 27 cylindrical blocks of microhybrid composite were made. The samples were randomly divided into nine groups (n = 3). The samples’ surface was treated differently per each group: acid etching (35% H3PO4, 30 s and 60 s), diamond bur milling, sandblasting and the combination of mechanical treatment and acid etching. The samples’ surface was observed by a scanning electron microscope (SEM) and a confocal microscope for observational study, and surface roughness (Ra) was recorded for quantitative analysis. Results: The images of the samples sandblasted with Al2O3 showed the greatest irregularity and the highest number of microcavities. The surfaces roughened by diamond bur showed evident parallel streaks and sporadic superficial microcavities. No significant roughness differences were recorded between other groups. The difference in roughness between the control group, diamond bur milled group and sandblasted group was statistically significant. (p &lt; 0.01). Comparison between the diamond bur milled group and the sandblasted group was also significant (p &lt; 0.01). Conclusion: According to our results, sandblasting is the best treatment to increase the surface roughness of a supra-nano composite.