Composite Resin Restorative Materials Research Articles

The effect of fluoride varnish application on colour change due to paediatric drug usage in polyacid-modified composite resin: an in vitro study.

Colour stability is important in the long-term aesthetic success of restorative materials and is affected by both internal and external factors. Internal discolourations are due to the properties of the restorative materials. External discolourations can be associated with frequent consumption of food and beverages and the use of suspensions or syrups containing colourants/additives. Fluoride varnish application has an important place in preventive dentistry. The purpose of the research was to examine the protective effect of fluoride varnish application on the colour change on polyacid-modified composite resin restorative materials caused by the use of various paediatric drugs. Two hundred ten discs were prepared from polyacid-modified composite resin material and divided into two groups: flouride varnish was applied to one group and flouride varnish was not applied to the other group. The groups were further divided into seven subgroups and the samples were kept in artificial saliva, amoxicillin + clavulanic acid, cefuroxime axetil, clarithromycin, paracetamol, ibuprofen, and iron supplement drug solutions. The colour change values of the discs were measured using a spectrophotometer device before immersion in the drug solutions and on the 7th, 14th, 21st, and 28th days after the immersion. The obtained data were calculated and statistically evaluated using IBM SPSS V23 software. It was found that the application of fluoride varnish in the iron supplement drug group prevented the colour change of the polyacid-modified composite resins for 28 days. In the amoxicillin + clavulanic acid, cefuroxime axetil, and paracetamol groups, the fluoride varnish did not prevent colour change in the polyacid-modified composite resin restorative materials at the end of the 14th day. It is thought that fluoride varnish application may be beneficial as a preservative in the colour change of polyacid-modified composite resins due to the use of various paediatric drugs, and this protective feature may be effective for a specific period of time.

How do different intraoral scanners and milling machines affect the fit and fatigue behavior of lithium disilicate and resin composite endocrowns?

The aim of this in vitro study was to evaluate the effect of the combinations of two different intraoral scanners (IOS), two milling machines, and two restorative materials on the marginal/internal fit and fatigue behavior of endocrowns produced by CAD-CAM. Eight groups (n= 10) were considered through the combination of TRIOS 3 (TR) or Primescan (PS) IOS; 4-axes (CR; CEREC MC XL) or 5-axes (PM; PrograMill PM7) milling machines; and lithium disilicate (LD; IPS e.max CAD) or resin composite (RC; Tetric CAD) restorative materials. Specific surface treatments were applied to each material, and the bonding to its corresponding Endocrown-shaped fiberglass-reinforced epoxy resin preparations was performed (Variolink Esthetic DC). Computed microtomography (μCT) was performed to assess the marginal/internal fit, as well as a mechanical fatigue test (20 Hz, initial load = 100 N/5000 cycles; step-size = 50 N/10,000 cycles until a threshold of 1500 N, then, the step-size was increased if needed to 100 N/10,000 cycles until failure or a threshold of 2800 N) to evaluate the restorations long-term behavior. Complementary analysis of the fracture features and surface topography in scanning electron microscopy was performed. Three-way ANOVA and Kaplan-Meier test (α = 0.05) were performed for marginal/internal fit, and fatigue behavior data, respectively. PS scanner, CR milling machine, and RC endocrowns resulted in a better marginal fit compared to their counterparts. Still, the PM machine resulted in a better pulpal space fit compared to the CR milling machine. Regardless of the scanner and milling machine, RC endocrowns exhibited superior fatigue behavior than LD ones. LD endocrowns presented margin chipping regardless of the milling machine used. Despite minor differences in terms of fit, the ‘IOS’ and ‘milling machine’ factors did not impair the fatigue behavior of endocrowns. Resin-composite restorations resulted in a higher survival rate compared to glass-ceramic ones, independently of the digital devices used in the workflow.

Antibacterial Agents for Composite Resin Restorative Materials: Current Knowledge and Future Prospects.

Resin composites became the material of choice for direct restorations in anterior and posterior teeth. Despite the revolutionary improvement in the material, restoration failure is still a major drawback due to the material's inherent negative properties, including a lack of antibacterial effects. Therefore, many attempts have been made to incorporate antibacterial agents into resin composite materials to improve their antimicrobial properties and prevent secondary caries formation. Multiple laboratory studies have been conducted using different antibacterial agents, such as quaternary ammonium compounds, methacryloyloxydodecylpyridinium bromide, magnesium oxide nanoparticles, chlorhexidine, and chitosan. This review provides a glance at the current status of these materials and the research directions needed in the future.

Mouthwashes: Surface Hardness and Accuracy of Dual-cured Visible Light-Cured Composite

In the oral environment, the longevity and durability of aesthetic composite resin restorative materials are critical considerations. However, many studies have been done on the effect of certain mouthwashes on the surface hardness and accuracy of composite resin. Therefore, this study aims to examine the effect of GUM® alcohol-free and Listerine alcohol-contained mouthwashes on the surface hardness and dimensional accuracy of cured and dual-cured visible light-cured composite.Methods: Thirty-disc specimens of Nanohybrid light-cured composite resin were prepared according to ISO standardization (4049/2000). The sample was divided into three groups (n=10), the Control non-treated in distilled water; Alcohol-free GUM® and Alcohol-contained Listerine mouthwashes. The surface hardness and dimensional accuracy of specimens were measured at different immersion intervals. These include initial immersion, after one and four weeks, and after the light dual-curing procedure. Data were analyzed via one-way ANOVA (post-hoc Tukey test) performed at a significant P-value of (p ≤.05) and confidence level of 95%.Conclusion: After the dual-curing process, the alcohol-free GUM® mouthwash showed a reduction in the surface hardness of the composite material. Listerine mouthwash had a static reduction in the composite specimen in diameters.

Influence of Heliobond on Microtensile Bond Strength of a New BIS-GMA Free Versus BIS-GMA Containing Composite Resin Restoration

AIM: The main objective of this study was to assess the micro-tensile bond strength (µTBS) of a free bisphenol-a-diglycidyl-ether-dimethacrylate (Bis-GMA) resin composite restorative material compared to a Bis-GMA-containing resin composite following the application of a hydrophobic coating (heliobond). MATERIALS AND METHODS: A flat occlusal dentin surface was exposed in a total of eighty extracted teeth that were removed for periodontal reasons. Teeth were divided into two main equal groups according to the type of applied filling materials: BIS-GMA-free versus BIS-GMA-containing resin composite (n = 40). Each main group was subdivided into two equal subgroups (n = 20) according to the application of Heliobond (hydrophobic resin coating). Heliobond has been applied after adhesive application and before resin composite application. The first group was restored by a Free Bis-GMA Resin Composite (Admira, Voco, Germany); the second group was restored by a Bis- GMA-containing resin composite (Grandio, Voco, Germany). Each tested restorative material was applied and cured according to the manufacturer’s instructions. RESULTS: Regardless of different composite and adhesive types, there was a statistically significant difference (p < 0.05) among all subgroups. Specimens with Heliobond recorded a higher µTBS mean value (30.46 ± 6.7 megapaskal [MPa]) than groups without Heliobond, which recorded µTBS mean value (23.95 ± 9.02 MPa). CONCLUSION: Application of an extra hydrophobic layer coating (Heliobond) has improved the performance of the µTBS of the adhesive systems utilized with the new BIS-GMA-free versus BIS-GMA-containing composite resin

Scope of an alkasite restorative material in paediatric dentistry: A review

Regardless of barriers linked to the patient’s age and behaviour, restoring primary teeth can be technically challenging, and researchers have long searched for an appropriate replacement for glass ionomer cement, composites, and silver amalgam that is cost-effective, fluoride-releasing, convenient to use, and fulfils both strength and acceptable aesthetics. An Alkasite is a resin -based modified composite resin restorative material, comprising alkaline fillers responsible for leaching acid-neutralizing ions like fluoride, calcium, and hydroxide ion. This Alkasite Cention-N is available in A2 tooth shade and has advantages of both Amalgam and GIC and provides better aesthetics and high flexural strength with the additional characteristic of optional light-curing.

Evaluating the Effect of Active Charcoal-Containing Toothpaste on Color Change, Microhardness, and Surface Roughness of Tooth Enamel and Resin Composite Restorative Materials.

Thirty-six bovine incisors and resin composite samples were prepared, stained with black tea, and then randomly divided into two groups. The samples were brushed with a charcoal-containing toothpaste (Colgate® MAX WHITE) and daily toothpaste (Colgate® Max Fresh) for 10,000 cycles. Before and after brushing cycles, color variables (ΔL, Δa, Δb), total color change (ΔE), plus Vickers microhardness were evaluated. Two samples of each group were prepared for surface roughness assessment via atomic force microscope. Data were analyzed by Shapiro-Wilk, Independent sample t-test and Mann-Whitney U tests. According to the obtained results, ΔE and ΔL were significantly higher whereas Δa and Δb were noticeably lower in charcoal-containing toothpaste group in comparison with daily toothpaste in both composite and enamel samples. The microhardness of samples brushed with Colgate® MAX WHITE was significantly higher than that of Colgate® Max Fresh in enamel (P = 0.04), whereas no significant difference was found in composite resin samples (P = 0.23). Colgate® MAX WHITE enhanced the roughness of both enamel and composite surfaces. The charcoal-containing toothpaste could improve the color of both enamel and resin composite with no negative effect on microhardness. Nevertheless, its adverse roughening effect should be considered occasionally on composite restorations.

Evaluation of Micro-Tensile Bond Strength of A New Resin Composite Restorative Material at Two Different Dentin Depth After Aging (An In-Vitro Study)

Evaluation of Micro-Tensile Bond Strength of A New Resin Composite Restorative Material at Two Different Dentin Depth After Aging (An In-Vitro Study)

Evaluation of Fracture Toughness and Micro hardness of Three Current Resin Composite Restorative Materials.

Evaluation of Fracture Toughness and Micro hardness of Three Current Resin Composite Restorative Materials.

Evaluation of Fracture Resistance in Maxillary Premolar Teeth Restored with Different Direct Composite Restorative Material

Purpose: This study was conducted to evaluate the effect of three direct resin composite restorative materials on fracture resistance in mesio-occluso-distal (MOD) cavities prepared in maxillary premolars. Materials and Methods: A total of 25 maxillary premolars were collected and then divided into five main groups (n=5). Group 1 (positive control group): sound teeth with no cavity preparation. Group 2 (negative control group): MOD cavities with no restoration. Group 3: MOD cavities restored with nanocomposite FILTEK™ Z350 XT Group 4: MOD cavities restored with simplified universal composite OptiShade™ and Group 5: MOD cavities restored with universal nano-filled composite Estelite® Sigma Quick. Results: Group 5 showed the maximum fracture strength value (ranged from 1170-1355 N) followed by Group 4 (998.1- 1158 N) then Group 3 (900.9-1097 N) followed by Group 1 (positive control) with fracture strength value ranging from 836.1 to 1059 N. Group 2 (negative control) showed the minimum fracture strength value ranged (380.6-631.6 N). For the significance evaluation of different groups, One-Way ANOVA was performed followed by Tukey`s post hoc test for multiple comparisons which revealed all significant differences between different groups as P-value < 0.05 except for (group 1 # group 3), (group 1 # group 4) and (group 3 # group 4) respectively which were insignificantly different as P-value > 0.05. Conclusion: Reinforcement of the teeth could be achieved after MOD cavity preparation in maxillary premolars through proper restorative procedures.

Mechanical Stability of Self-Adhesive/Ion-Releasing Resin Composites

The purpose of this study was to assess the effects of water storage on the surface microhardness (VHN) and fracture toughness (K1C) of two self-adhesive restorative materials compared to traditional resin composite and resin-modified glass ionomer cement (RMGIC) restorative materials. Methods: Two self-adhesive materials (Activa and Vertise Flow), a nonflowable composite (Filtek Z250), and an RMGIC (Fuji II) were evaluated. Hardness measurements (n = 12) were recorded at three time intervals: (i) one-hour post-irradiation; (ii) after one day of storage in water at 37 °C; and (iii) after 90 days of storage in water at 37 °C. Fracture toughness (K1C) measurements (n = 12) were conducted after one day of storage in water at 37 °C and 90 days of storage in water at 37 °C. ANOVA and Tukey post hoc tests were used for statistical analysis. Results: Baseline VHN data were 38.2–58.3, decreasing significantly to 28.8–55.6 following 90 days of water storage. The Filtek Z250 had the highest VHN before and after storage, while the Activa had the lowest. KIC values varied between 0.98–1.32 MPa·m0.5. The highest value was for the Filtek Z250 while the Fuji II showed the lowest value (after both 1 and 90 days of storage in water). However, KIC values decreased significantly after storage, except for the Fuji II. Conclusion: Self-adhesive/ion-releasing resin composites were negatively affected by water storage. Material reinforcements are possible future areas to explore.

Physico-Mechanical Characteristics of Ormocer and Bulk Fill Composite Resin Restorative Materials: An in-vitro Study

Introduction: Bulk Fill (BF) resins and Ormocers are recently introduced composite restorative materials in order to overcome the disadvantage of polymerisation shrinkage exhibited by most of the conventional resin-based composites. Aim: To evaluate the physical and mechanical properties of Organically Modified Ceramics (Ormocers) in comparison with BF composite resin restorative material. Materials and Methods: In this in-vitro study, 20 human extracted premolars were allocated into two groups of 10 each. ORM (Group-1 Admira fusion, n=10) and BF (Group-2 Filtek BF, n=10) composite materials were used to prepare and restore Class-V cavities. The teeth were subjected to thermocycling and immersed in 1% methylene blue dye solution. Along the lateral walls of each sectioned specimen, depth of dye penetration was measured under the stereo microscope. A total of 20 rectangular (25x2x2 mm) and 20 disc (10x2 mm) shaped specimens of the above-mentioned materials were fabricated. Specimens of Flexural Strength (FS) were tested with the universal testing machine and Vickers hardness tester used for Surface Hardness (SH) evaluation. The data was statistically analysed using an unpaired t-test. Results: Total of 20 extracted premolars were analysed. On inter-group comparison, it was observed that mean dye penetration was lowest for Group-1 (0.6±0.69) compared to Group-2 (2±0.81) and the difference observed was statistically significant (p=0.001). BF exhibited a lower FS of 211.69±43.9 compared to Ormocer 326.19±90.3, the difference is statistically significant (p=0.001). However, BF exhibited a higher SH of 38.3±0.15 compared to Ormocer 33.70±0.86, and the difference is statistically significant (p-value<0.001). Conclusion: Ormocer exhibited improved marginal integrity and also higher FS compared to BF resin restorative materials. However, BF exhibited higher SH values compared to Ormocer.

The effect of antibacterial agents of composite resin materials in dental caries prevention and reduction of flexural strength of the material: Systematic review and meta-analysis

Background: The present study aimed to evaluate the antibacterial agents of composite resin materials, their efficacy in caries prevention, and their impact on the mechanical properties (flexural strength) of composite resin restorative materials. Methods: In this systematic review and meta-analysis, all published articles on the effects of antibacterial properties of composite resin materials in the prevention of dental caries (between 2005 to 2020) were evaluated using valid databases, including PubMed, Google Scholar, Web of Science, ISI, Scopus, Cochrane, ProQuest, and Embase, found by searching the keywords "anti-bacterial agents," "composite resins," "dental restoration," and "dental caries" according to the MeSH system. The context of the studies was extracted and subjected to modified CONSORT. The required data were extracted and analyzed with the Comprehensive Meta-Analysis software. Results: According to the results of the random effect model, the heterogeneity of biofilm colony forming unit (CFU) average was -1.90 (CI: -1.68 to -2.13). The mean value of the control group was higher than the intervention. The heterogeneity of flexural strength (FS) average was -11.92 (CI: -8.30 to -15.55). The mean value of the control group was higher than the intervention group. The heterogeneity of thiazolyl blue tetrazolium bromide (MTT) absorbance average was -0.90 (CI: -0.65 to -1.14). The mean value of the control group was higher than the intervention group. Conclusion: The results of the present study showed that the antibacterial agents had a significant effect on the caries prevention properties of the composite resin materials; however, due to the bias related to different control groups, laboratory conditions, and mismatch between in vitro and in vivo conditions, more studies are needed in this regard.

The Effect of Gastric Acid on the Surface Properties of Different Universal Composites: A SEM Study.

The aim of this study is to compare surface roughness and microhardness changes of three monochromatic (Omnichroma, Vittra Unique, and Charisma Diamond One) and three universal shade (Neo Spectra ST, G-ænial A'CHORD, and Nova Compo C) resin composites after exposure to simulated gastric acid. A total of 144 disc-shaped specimens (24 discs of each composite resin) were prepared using plexiglass molds (R = 5 mm × h = 2 mm) for evaluation from each material. Specimens of each material were divided into two main groups for the evaluation of the microhardness and surface roughness and also two subgroups for 7- and 14-day exposures to simulated gastric acid. Initial microhardness and surface roughness measurements of all samples were measured before immersion (T1) followed by exposing the samples to simulated gastric acid for 7 days (T2) and 14 days (T3), and then, the microhardness and roughness measurements were repeated. Randomly selected specimens of each material for each of the time intervals (T1, T2, and T3) were evaluated with scanning electron microscopy (SEM). One-way ANOVA revealed that the surface roughness and hardness values of all tested composite resin restorative materials show no statistically significant difference for the initial (T1) value (p > 0.05). Regarding the 7th day (T2) and 14th day (T3) surface roughness and microhardness value of all composites, there are statistically significant differences between the groups (p < 0.05), while there was no statistically significant difference between the surface hardness reduction percentage between the time intervals (p > 0.05). As a result of this in vitro study, increase in surface roughness and decrease in microhardness of the tested universal composite materials when exposed to simulated gastric acid were statistically significant.

In vitro surface and color changes of tooth-colored restorative materials after sport and energy drink cyclic immersions.

There has not been any research conducted on surface properties and color changes from sport and energy drinks on bulk-fill resin composite, nanohybrid resin composite and glass ionomer restorative material. The aim of this in vitro study was to investigate the effect of sport and energy drinks on surface hardness, roughness and color changes of bulk-fill resin composite, nanohybrid resin composite and glass ionomer restorative material, and to also evaluate the acidity and titratable acidity of the drinks. One hundred and forty-seven specimens of each tooth-colored restorative material were prepared in a polytetrafluoroethylene mold (10mm. in diameter and 2mm. in thickness). Before immersion, baseline data of hardness, roughness, and color value were recorded. Each material was divided into 3 groups for sport drink, energy drink, and deionized water (serving as a control). The specimens were immersed in a storage agent for 5s, then in artificial saliva for 5s alternately for 24 cycles, and then stored in artificial saliva for 24h. The immersion cycle was repeated for 14days and hardness, roughness and color values were measured at 7 and 14days. After immersion, the glass ionomer restorative material had statistically less hardness, more roughness and more color changes than the others (P < 0.05). Energy drink groups statistically caused more surface and color changes than sport drink groups (P < 0.05). Sport and energy drinks affected hardness, roughness, and color changes in all the tooth-colored restorative materials evaluated.

Surface roughness changes of two composite resin restorative materials after thermocycling.

Composite is usually a mixture of two phases. The composites used in dentistry have high durability. The individual properties of each phase are important to increase the mechanical property of the composite. This study aimed to determine the surface roughness changes of two composite resin restorative materials after thermocycling. Two of the commercially available composites were chosen (RestoFill and SwissTEC). The composite disks of dimension 10 mm diameter and 3 mm height were prepared using silicone molds, and every increment was light cured for 30 s. A stylus profilometer was used to assess the surface roughness prethermocycling, and then, the disks were subjected to an integrated thermocycler (T.S-4.4) for 1000 cycles. The postsurface roughness was obtained after the thermocycling process using the same stylus profilometer. The surface parameter values before and after thermocycling of the SwissTEC sample is less than that of RestoFill. There was a significant difference between the Rz and Rq values of the two different commercially available composite materials. Thus, the present study concludes that thermocycling influenced the surface roughness of composite resin and increased the surface roughness of both the RestoFill and SwissTEC composites.

Evaluation Of Microleakage In Class II Cavity Preparation Restored Using Zirconomer As Liner And Composite Resin In Closed-Sandwich Technique

Introduction : Microleakage in class II restoration mostly occur due to masticatory stresses and thermal changes which leads to secondary or recurrent caries. To overcome this problem of marginal leakage, Glass Ionomer cement base was used to substantially replace the composite resin restorative material in the proximal box.This technique is known as “composite-laminated GIC” or “sandwich” restoration. In the traditional “closed sandwich” technique there is placement of the zirconomer at the base of the proximal box so as it falls just short of the external cavo surface. This procedure offers no protection from proximal caries until failure of the dentine bonding agent.Materials and method : Twenty-six sound healthy teeth with absence of caries, restoration, cracks and white spots were selected.The proximal box was 4 mm wide bucco-lingually; whereas, the pulpal and axial walls measured to be 2 mm deep. After placement of the Zirconomer at the base of the proximal box such that it falls just short of the external cavo surface, etching and bonding of Zirconomer was done. Composite resin was placed in the proximal box and occlusal surface, leaving the zirconomer encased within the preparation. Samples were then processed for thermocycling. With the help of modelling wax, the apexes of the root were sealed to prevent the ingress of dye. The samples were then coated with nail varnish, applying two coats around all surfaces of teeth leaving 2 mm of the marginal area around the restorations. Immersion of sample was then done in methylene blue dye. Samples were then washed under running water for one minute and then air dried. In next step restorations were sectioned longitudinally through the centre of the tooth. They were sectioned by using diamond disc along with water as coolant. Sections were examined at 32x magnification under a stereomicroscope. SEM observations at the gingival margins of the specimens restored with closed sandwich technique depicted less satisfactory marginal adaptation. Conclusion : It can be concluded that none of the technique tested are free of microleakage. Zirconomer placed in the gingival floor of class II composite restoration may be a practical method to reduce microleakage.

Evaluation of Glass-Ionomer versus Bulk-Fill Resin Composite: A Two-Year Randomized Clinical Study.

Background: The aim of this split-mouth design research was to compare the clinical performance of a glass-ionomer cement system on Class I/II cavities against the clinical performance of bulk-fill resin composite restoration materials. Methods: Thirty-five patients were randomized and enrolled in the study, aged between 10 and 12 years, all of whom had a matched pair of permanent mandibular carious molars with similar Class I/II. A total of 70 restoration placements were performed. The patients were each given two restorations consisting of either a glass-ionomer cement with a nano-filled coating or a bulk-fill resin composite after the use of a self-etch adhesive. The cumulative survival rates were estimated using log-rank test and the Kaplan–Meier method. For comparison of the restorative materials in line with the modified Ryge, the McNemar test and the Wilcoxon signed rank test were employed. Results: With regard to retention, the glass-ionomer cement system and bulk-fill resin composite performed similarly in permanent molars in Class I/II cavities over a period of up to 24-months (p > 0.05). Over the 24-month period, Class I restorations showed statistically better survival rates than Class II restorations (p < 0.05). In the case of glass-ionomer cement systems, over the two-year period, more common chipping and surface degradations were observed. Conclusions: The glass-ionomer cement system and bulk-fill resin composite restorative materials display good clinical performance over a period of 24-months.

Impact of Resin Composite Restorative Material Pre-heating on Dental Pulp Temperature: A Laboratory study

Impact of Resin Composite Restorative Material Pre-heating on Dental Pulp Temperature: A Laboratory study

Twelve-month Clinical Performance Evaluation of a Glass Carbomer Restorative System.

The aim of this in vivo study was to evaluate the clinical one-year follow-up of a silica- and flouroapatite-reinforced glass carbomer filling material as compared to a resin composite restorative material. In this study, a total of 100 restorations were performed. Caries were removed conventionally with diamond burs. Half of the restorations were restored with nanocomposite resin (TEP) (Tokuyama Estelite, Tokuyama Dental, Japan) and the other half were restored with glass carbomer (GC) material (GCP Dental, The Netherlands). Each restorative material was applied according to the manufacturer's instructions. Restorations were evaluated with modified USPHS criteria at the end of the first week, 6 months, and 12 months. Data were analyzed using Fisher's Exact Chi-Square test, Fisher Freeman Halton Test, and Continuity (Yates) Correction. The Wilcoxon sign test was used for intra-group comparisons of the parameters. When the filling materials were compared with one another, a statistically significant difference was observed in the 12th month on the marginal discoloration. A statistically significant difference was observed between the two materials in the 6th month on the marginal adaptation (p<0.05). In view of these results, there is a need to improve the physical properties of the GC filling material in further in vivo studies.