Composite Restorative Materials Research Articles

The Chemical and Optical Stability Evaluation of Injectable Restorative Materials Under Wet Challenge.

To investigate and compare the chemical and optical stability of four restorative composite materials: two injectable resins, one flowable resin and one compomer. Two injectable nano-filled composite resins: G-aeniel Universal (GU) and Beautifil Injectable XSL (BI), a flowable composite resin: Filtek Supreme Flowable (FS) and a compomer: Dyract Flow (DF), in A2 shade were tested and compared. Water sorption and solubility were conducted according to ISO4049: 2019 standard; ICP-OES and F-ion selective electrode were used to test the elemental release; Degree of conversion (DC) was obtained by using FTIR; water contact angle was obtained by static sessile drop method, and spectrophotometer was used for optical properties (ΔE*, ΔL* and TP). SPSS 28.0 was used for statistical analysis and the significant level was pre-set as α=0.05. GU performed the best in water sorption and solubility, FS had the lowest elemental release, the best colour stability, and the highest DCIM and DC24-h. DF, the compomer had the lowest, and GU and BI, the injectable composites had the largest water contact angle, respectively. Correlations were found between water sorption and water solubility. The four composite restorative materials showed different chemical and optical behaviours. Overall, composite resins performed better than compomer, while additional laboratory and in vivo tests are necessary to obtain a more comprehensive comparison between injectable and flowable composite resins. Wsp and Wsl are influenced by many common factors, and the values are highly positively related. A comprehensive understanding of materials is crucial before selecting materials for clinical practice. Composite resins rather than compomers are recommended because of their exceptional properties, which make them eligible for a wide range of clinical applications and an elongated lifespan.

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.

Effect of different beverages and polishing techniques on colour stability of CAD/CAM composite restorative materials

Objectives: The aim of this article was to compare the colour stability of short fibre-reinforced computer-assisted design/computer-assisted manufacturing (CAD/CAM) composite (SFRC CAD) to commercially available CAD/CAM materials following prolonged immersion in a variety of beverages. Furthermore, the influence of the polishing technique was evaluated. Materials and methods: A total of 120 rectangular specimens (10 mm length × 14 mm width × 2 mm thickness) were prepared from SFRC CAD, IPS e-max, Cerasmart 270, Celtra Duo, Enamic, and Brilliant Crios. The specimens underwent polishing through either a laboratory polishing machine equipped with 4000-grit silicon carbide paper or chairside polishing using Sof-Lex spiral. Twenty specimens of each tested CAD/CAM material were randomly divided into four groups (n = 5) based on the staining solution used in order to evaluate the colour stability of the materials. Group 1: distilled water, Group 2: coffee, Group 3: red wine, Group 4: coke. Using a spectrophotometer, the colour changes (∆E) of all CAD/CAM materials were assessed at baseline, and after 1 and 12 weeks of staining. Three-way analysis of variance was used to analyse the data (α = 0.05). Results: The staining solution and material type showed a significant influence on the CAD/CAM specimens’ colour stability (p < 0.05), while polishing method had no significant influence (p > 0.05). The average ∆E values for specimens submerged in wine were considerably higher (p < 0.05) than those for the other solutions. SFRC CAD, Cerasmart 270, and Enamic displayed the highest ∆E values in wine (p < 0.05). Conclusions: The colour stability of tested SFRC CAD was comparable to other composite-based CAD/CAM materials, while IPS e.max exhibited the highest level of colour stability.

Effect of Bonding Agents on the Shear Bond Strength of Tooth-colored Restorative Materials to Dentin: An In Vitro Study.

The aim of the study is to determine the difference in the shear bond strengths to dentin among dental composite (Filtek Z350®, 3M), compomer (Dyract Flow®, Dentsply) and Giomer (Beautifil®, Shofu) with 3MTM Single BondTM Universal Adhesive (SBU) (7th generation, self-etch, single solution adhesive) and AdperTM Single Bond 2 Adhesive (ASB) (5th generation, total-etch, two solution adhesive). Sixty extracted human permanent teeth were collected, cleansed of debris, and placed in distilled water. The samples were segregated into two groups depicting the two bonding agents-AdperTM (ASB) and 3MTM Single Bond Universal (SBU) and sub-grouped into three groups depicting the three restorative materials (Composite, Giomer, and Compomer) used. Groups were respresented as follows: Group I-ASB + Composite; Group II-ASB + Giomer; Group III-ASB + Compomer; Group IV-SBU + Giomer; Group V-SBU + Compomer; Group VI-SBU + Composite. After applying the bonding agent as per the manufacturer's instructions, following which the restorative material was placed. A Universal Testing Machine (Instron 3366, UK) was employed to estimate the shear bond strength of the individual restorative material and shear bond strengths were calculated. Composite bonded with SBU (group VI) displayed the greatest shear strength (11.16 ± 4.22 MPa). Moreover, Giomers and flowable compomers displayed better bond strengths with ASB compared with their SBU-bonded counterparts. These results mark the importance of careful material selection in clinical practice and the bonding agent used to achieve optimal bond strength and enhance the clinical longevity and durability of dental restorations. From a clinical perspective, to avoid a compressive or a shear failure, it would be preferrable to use a direct composite restorative material with SBU (Single bond universal adhesive, 7th generation) to achieve maximum bond strength. How to cite this article: Kuchibhotla N, Sathyamoorthy H, Balakrishnan S, et al. Effect of Bonding Agents on the Shear Bond Strength of Tooth-colored Restorative Materials to Dentin: An In Vitro Study. J Contemp Dent Pract 2024;25(3):245-249.

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.

Performance Assessment of Three Similar Dental Restorative Composite Materials via Raman Spectroscopy Supported by Complementary Methods Such as Hardness and Density Measurements.

(1) Background: A widespread problem in oral health is cavities produced by cariogenic bacteria that consume fermentable carbohydrates and lower pH to 5.5-6.5, thus extracting Ca2+ and phosphate ions (PO43-) from teeth. Dental restorative materials based on polymers are used to fill the gaps in damaged teeth, but their properties are different from those of dental enamel. Therefore, a question is raised about the similarity between dental composites and natural teeth in terms of density and hardness. (2) Methods: We have used Raman spectroscopy and density and microhardness measurements to compare physical characteristics of several restorative dental composites at different polymerization intervals. (3) Results: XRVHerculite®, Optishade®, and VertiseFlow® showed the very different characteristics of the physical properties following four polymerization intervals. Of the three composites, OptiShade showed the highest polymerization rate. (4) Conclusions: Only fully polymerized composites can be used in teeth restoring, because incomplete polymerization would result in cracks, pitting, and lead finally to failure.

Evaluation the Fracture Resistance of Endodontically Treated Teeth Restored With Different Post and Core Materials

Widespread use of prefabricated post that provides retention and support for core and the final crown has caused manufacturers to produce different types of post materials. The aim of this study was to evaluative the fracture resistance of two types of post materials and two types of core material. Forty extracted human mandibular premolar were selected. After root canal preparation and obturation with gutta percha the roots were divided into two groups according to the type of post material, group F restored with fiber post and group T restored with titanium post then each group was subdivided into two subgroup according to the type of core materials which include composite and amalgam restorative materials. Then all the teeth were subjected to compressive load at 130o angle from the horizontal plan at a 5mm/min crosshead speed until fracture. Results showed that there was significant different between groups in term of fracture loads (P= 0.0156). Also the fracture loads of teeth restored with titanium post and composite core has highest mean fracture load (812N), whereas teeth restored with fiber post and amalgam core demonstrated the lowest mean fracture load (643.1N). The study concluded that the teeth restored with metal titanium post were more fracture resistant than those restored with fiber posts. But the combination of a fiber post and composite core has the favorable mode of fracture that considered reparable, while considered unfavorable when restored with titanium post.

Evaluation of Sealing Ability of New Composite Filling Material

This study was conducted to investigate the sealing ability (microleakage) of new composite restorative materials at tooth/composite interface.Thirty non carious, extracted human premolars teeth were mounted in acrylic resin, the teeth were randomly divided into three groups (n=10) according to the type of composite (tetric T-Econom, Evo ceram,IPS Empress). A standardize class V (5×3×2) mm dimensions cavity was prepared on the facial surface of each tooth (each group with corresponding bur type). After the specimens were filled with three types of composite restoration. They stored for one month in 37ºc distilled water, thermo cycled for 500 cycles between (5ºc & 55ºc) and immersed in 2% methylene blue solution for 24h., and then sectioned longitudinally. For both occlusal and gingival margins, dye penetration at the tooth/composite interfaces were scored from 0-3 under stereomicroscope at a magnification x10. Data were analyzed using unpaired T-test, ANOVA, and Duncan’s multiple rang test at 5% significant level.Kruskal-wallis test show that there was a significant difference in microleakage between the three types of composite it represent that there was less microleakage in group filled with IPS Empress while tetric T-Econom show the highest leakage.There was no significant difference in microleakage between IPS Empress and Evo ceram composite filling.AS Conclusions; Within the limitations of this in vitro study the results show that there was less microleakage in the cavities filled with IPS Empress composite and EVO ceram composite as compared with Tetric T-Econom composite.

Investigation of the surface of light-curing dental materials after pre-polymerization heating

Despite the great variety and wide application of light-cured composite restorative materials for the treatment of hard tissue diseases, the issue of longevity of restorations remains relevant to this day. One of the criteria for the long-term durability of a composite restoration is the finish of the restoration. Poor polishing and surface roughness significantly reduce theservice life of the restoration and provide a good environment for biofilm adhesion, loss of luster of the restoration, and caries recurrence. Thus, methods affecting the reduction of surface relief in restorations remain a current issue. Aim. To evaluate the surface roughness and porosity of composite filling materials after pre-polymerization heating. Materials and methods. Sixty composite samples were prepared in the form of 1 mm thick, 1.2 cm diameter disks. The samples were divided into 2 groups depending on the presence of pre-polymerization heating. Atomic force microscopy (AFM) was used to measure the roughness and to visualize the surface morphology of the samples. Porosity was measured using a vacuum sputtering unit, and a scanning electron microscope was used to obtain micrographs of the sample. Results. The use of pre-polymerization heating of composite filling materials in dental practice will allow dentists to significantly reduce the expression of the relief of the composite restoration by reducing the roughness and pore volume in the matrix of the composite filling material, which will certainly optimize the finishing of the restoration. Conclusions. Pre-polymerization heating has a positive effect on the surface topography of the composite restoration, reducing its roughness and porosity, which improves the stage of finishing: obtaining a dry gloss, ensuring the duration of color stability, as well as reducing the adhesion of microorganisms to the filling material, thereby increasing the longevity of the composite restoration.

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.

Chemical Modification of Dental Dimethacrylate Copolymer with Tetramethylxylylene Diisocyanate-Based Quaternary Ammonium Urethane-Dimethacrylates-Physicochemical, Mechanical, and Antibacterial Properties.

In this study, two novel quaternary ammonium urethane-dimethacrylates (QAUDMAs) were designed for potential use as comonomers in antibacterial dental composite restorative materials. QAUDMAs were synthesized via the reaction of 1,3-bis(1-isocyanato-1-methylethyl)benzene with 2-(methacryloyloxy)ethyl-2-decylhydroxyethylmethylammonium bromide (QA10+TMXDI) and 2-(methacryloyloxy)ethyl-2-dodecylhydroxyethylmethylammonium bromide (QA12+TMXDI). Their compositions with common dental dimethacrylates comprising QAUDMA 20 wt.%, urethane-dimethacrylate monomer (UDMA) 20 wt.%, bisphenol A glycerolate dimethacrylate (Bis-GMA) 40 wt.%, and triethylene glycol dimethacrylate (TEGDMA) 20 wt.%, were photocured. The achieved copolymers were characterized for their physicochemical and mechanical properties, including their degree of conversion (DC), glass transition temperature (Tg), polymerization shrinkage (S), water contact angle (WCA), flexural modulus (E), flexural strength (FS), hardness (HB), water sorption (WS), and water leachability (WL). The antibacterial activity of the copolymers was characterized by the minimum bactericidal concentration (MBC) and minimum inhibitory concentration (MIC) against Staphylococcus aureus and Escherichia coli. The achieved results were compared to the properties of a typical dental copolymer comprising UDMA 40 wt.%, Bis-GMA 40 wt.%, and TEGDMA 20 wt.%. The introduction of QAUDMAs did not deteriorate physicochemical and mechanical properties. The WS and WL increased; however, they were still satisfactory. The copolymer comprising QA10+TMXDI showed a higher antibacterial effect than that comprising QA12+TMXDI and that of the reference copolymer.

Automotive Technology Revolutionized Restorative Dentistry Discovery of Alpha-diketone/Amine Catalyst: Part I.

A full account of early research that led to the discovery of the Alpha-diketone and Amine systems by two Imperial Chemical Industries (ICI) researchers. UK Chemists in the mid-sixties marked the beginning in the early development of a composite resin cured with visible light spectrum into a solid mass. Its incorporation into the newly developed Urethane based resin, led to conceiving the idea of developing the first light-activated restorative composite resin, which formed the prototype of modern composite restorative materials. How all that came about, and the ideas that were conceived and pursued in the development of these systems are discussed in detail.

Biomechanical performance of resin composite on dental tissue restoration: A finite element analysis.

This study investigates the biomechanical performance of various dental materials when filled in different cavity designs and their effects on surrounding dental tissues. Finite element models of three infected teeth with different cavity designs, Class I (occlusal), Class II mesial-occlusal (MO), and Class II mesio-occluso-distal (MOD) were constructed. These cavities were filled with amalgam, composites (Young's moduli of 10, 14, 18, 22, and 26 GPa), and glass carbomer cement (GCC). An occlusal load of 600 N was distributed on the top surface of the teeth to carry out simulations. The findings revealed that von Mises stress was higher in GCC material, with cavity Class I (46.01 MPa in the enamel, 23.61 MPa in the dentin), and for cavity Class II MO von Mises stress was 43.64 MPa, 39.18 MPa in enamel and dentin respectively, while in case of cavity Class II MOD von Mises stress was 44.67 MPa in enamel, 27.5 in the dentin. The results showed that higher stresses were generated in the non-restored tooth compared to the restored one, and increasing Young's modulus of restorative composite material decreases stresses in enamel and dentin. The use of composite material showed excellent performance which can be a good viable option for restorative material compared to other restorative materials.

Effect of Prolonged Water Aging on the Bond Strength and Marginal Seal of Three Novel Restorative Materials.

To assess and contrast the shear bond strength (SBS) and microbial leakage of Cention-N, Fuji IX, and nanohybrid composite restorative materials after being exposed to prolonged water aging. A total of 30 self-curing acrylic blocks were prepared for SBS analysis. Extracted teeth were affixed on the acrylic resin to incorporate the root section. To expose the occlusal dentin, 3 mm of the midcoronal portion was sectioned. The sectioned samples were allocated into the following three groups: Group I: Fuji IX; group II: Filtek Z350; and group III: Cention-N. Cylindrical plastic tubing was used to place each material as directed by the manufacturer and water aging for 7, 14, and 28 days at 37°C. Also, a universal testing machine (UTM) was utilized for testing followed by a scanning electron microscope (SEM). For microleakage analysis, a total of 30 class-V cavities were prepared. The prepared samples were allotted to respective groups; Later, 200 thermocycles at 5°C and 55°C were applied for 30 seconds to mimic the oral environment. The root apices sealed with sticky wax and the exception of a 1-mm around the edges of the restorations were then painted twice with clear nail varnish and submerged in 0.5% basic fuchsin dye at 37°C. Samples were washed, dried, and sectioned longitudinally followed by stereomicroscopic evaluation. Groups I (0.083), group II (0.083), and group III (0.102) did not show significant variation in the SBS after water degradation. At the end of 28 days of water aging, group III showed 33.3% adhesive failure and 66.7% mixed failure mode. For marginal leakage in group III, the mean and standard deviation (SD) were 334.90 ± 418.454 with the p = 0.001 showing a significant difference compared to groups I and II. Compared to nanohybrid composite and Fuji IX, Cention-N showed a superior SBS after being exposed to water aging and exhibited lesser marginal leakage. Cention-N outperformed in its marginal adaptation with superior shear resistance and can be considered as an alternative bulk filling material.

Cement-based ductile rapid repair material modified with self-emulsifying waterborne epoxy

Ordinary silicate cement repair materials are slow to set and harden, have low early strength, and cannot meet the demands of rapid repair, and the disadvantage of brittleness after repair is obvious. Calcium sulfoaluminate cement (CSA) is more suitable for use as a cementitious material for rapid repair materials due to its fast hardening and early strength characteristics, but this cementitious material still suffers from low bond strength and poor toughness, which cannot be effectively resolved. In recent years, polymer-modified cementitious materials have attracted a great deal of attention in the field of repair and reinforcement. Among the many polymer options, epoxy resins have become the most promising choice due to their excellent compatibility and coupling effect with cement hydration and their excellent overall performance. In this paper, a novel waterborne epoxy resin-CSA cement composite restoration material was prepared by using a self-synthesized waterborne epoxy resin (WEP). The mechanism by which WEP improves the performance of CSA cementitious restorative material was also elucidated. The results show that by adjusting the amount of WEP, the workability of the repair material can be regulated. WEP significantly improved the interfacial bond strength of the repair material, and the toughness of CSA cement repair material with 10% WEP increased by 32.2% and the tensile ductility increased by 93.8% compared to the control group. The fully cured WEP and CSA cement hydration products form a dense cross-linked network-like structure, which refines the pore structure of the repair material and improves the disadvantages of the highly brittle and low ductility of the repair material.

Comparison of fracture resistance of posterior tooth restored with cention-n, zirconomer and universal composite restorative material: An in-vitro study

The aim of this study was to access and compare fracture resistance of tooth restored with Cention-N, Zirconomer and Filtek Z350 XT. Seventy five extracted maxillary premolar were divided into five groups; (Group I) Unprepared intact teeth, (Group II) Teeth with class II mesio-occluso-distal (MOD) cavity prepared and unrestored, (Group III) Teeth with class II MOD cavity prepared and restored with Zirconomer (Shofu Inc), (Group IV) Teeth with class II MOD cavity prepared and restored with Cention N, (Group V) Teeth with class II MOD cavity prepared and restored with Universal Composite Restorative Material (Filtek Z350 XT). Specimen was individually tested in a universal testing machine for facture resistance. Filtek Z350 XT showed statistically significant fracture resistance as compared to Group II, Group III and Group IV (P<0.001). Cention-N showed better fracture resistance than Zirconomer but didn’t vary statistically. All the test restorative material showed acceptable fracture resistance under load. Long term clinical evaluation is required to access their behavior intraorally.

Assessment of colour modifications in two different composite resins induced by the influence of chlorhexidine mouthwashes and gels, with and without anti-staining properties: An in vitro study.

Chlorhexidine (CHX)-based products are the most effective chemical agents used in plaque control and oral disinfection. One of their side effects is tooth and restoration staining. For this reason, CHX products with anti-discolouration systems (ADS) have been developed. The aim of this in vitro study was to compare different CHX-based products (gel and mouthwash) with or without ADS in composite colour modification. Two hundred specimens were created, 100 of which were made of packable composite and 100 of flowable composite. After 24 h, colour coordinates (L*, a*, b*, C*, h°) were recorded using a spectrophotometer (T0). Then, all samples were subjected to a CHX/tea staining model and immersed in human saliva for 2 min. Composite specimens were divided in 10 groups (N = 20). Control groups (PC, FC) were soaked in distilled water and test groups (PG, PGads, FG, FGads, PM, PMads, FM and FMads) were immersed in CHX-based solutions or brushed with CHX gel. Then the cycle was repeated 6 times, and colour differences (ΔEab and ΔE00 ) were finally calculated. Through flowable composites, FC and FG showed the highest colour differences, respectively ΔEab = 3.48 ± 1.0, ΔE00 = 2.24 ± 0.6 and ΔEab = 2.95 ± 1.3, ΔE00 = 1.53 ± 0.6. In the composite groups instead, PM and PMads showed the highest colour differences, respectively ΔEab = 2.78 ± 1.3, ΔE00 = 1.94 ± 0.8 and ΔEab = 2.71 ± 1.4, ΔE00 = 1.84 ± 0.9. CHX-containing products are able to cause stains on restorative composite materials. Discolouration is more likely to occur in flowable composites than packable composites, and ADS-containing products cause fewer pigmentations than CHX products without ADS. Packable composites showed more staining after mouthwash treatment, whereas flowable composites underwent higher discolouration after treatment with gels.

Selection and ranking of dental restorative composite materials using hybrid Entropy-VIKOR method: An application of MCDM technique

The objective of this investigation was to design the selection and ranking of dental restorative composite materials using hybrid Entropy-VIKOR as the MCDM method. Eleven performance defining attributes (PDAs) of dental composites were considered to investigate the best formulation among the dental composites. The weight criteria of various PDAs of the dental composite were calculated by the Entropy method: PDA-1(0.0527), PDA-2 (0.0113), PDA-3(0.1692), PDA-4(0.1291), PDA-5(0.0207), etc. The VIKOR method was employed to demonstrate the rank of dental composites. As per the VIKOR method, the first rank was obtained by DHZ6, the second rank was by DHZ8, the third rank was by DHZ4, the fourth rank was by DHZ2, and the lowest rank was by DHZ0. The Hybrid Entropy-VIKOR method holds significance in the biomedical realm due to its capability to effectively address complex decision-making scenarios. Its ability to account for multiple criteria, uncertainties, and compromise solutions makes it particularly useful for enhancing decision-making processes in the biomedical field, where selecting the most suitable options is critical for patient outcomes and healthcare advancements.

The Impact of Adhesive-Containing Nanoparticles of ZrO2and TiO2 on Antimicrobial Effectiveness, the Strength of Bonding, and the Extent of Microleakage in Dentin Affected by Caries

Aims: Zirconium oxide (ZrO2) and Titanium dioxide (TiO2) nanoparticles (NPs) in-cooperated in a three-step etch and rinse adhesive against Lactobacillus survival rate, shear bond strength (SBS) and marginal leakage on CAD. Methods: Ninety premolars having occlusal carries to the middle third of the dentin were included. Inoculation of Lactobacillus on CAD surface was performed on 30 samples. The remaining 60 samples were then divided into three groups based on primer applied in three steps etch and rinse (n = 20) Group 1 (Optibond FL), Group 2: (Optibond FL + TiO2), and Group 3: (Optibond FL + ZrO2). The survival rate was assessed on the 30 samples. The remaining 60 samples were applied with Optibond FL bonding agent and composite restorative material. Microleakage, SBS, and failure mode were analyzed. The means and standard deviations (SD) were compared utilizing ANOVA followed by a post hoc Tukey multiple comparison test. Results: Specimens in Group 1 demonstrated the maximum numbers of Lactobacillus species and marginal leakage values. Group 2 specimens displayed the minimum count of bacteria, lowest microleakage scores, and highest bond values. However, Group 1 specimens showed the lowest bond integrity. Conclusions: ZrO2 and TiO2 NPs filled dental adhesive demonstrated better antimicrobial efficacy and bond strength. They also cause a reduction in marginal leakage at the resin dentin interface.

Effect of mouthwashes on the microhardness of aesthetic composite restorative materials.

Mouthwashes are increasingly being used worldwide. However, these preparations are known to have a negative impact on composite resin dental restorations. In this study, we aim to evaluate the effect of mouthwashes on the microhardness of such restorations. Thirty specimens of Tetric N-Ceram composite were prepared. Each composite specimen was cured for 40 seconds and kept in saline solution for 24 hours at 37 °C. Baseline microhardness of each specimen was recorded using an Innovatest Vickers Micro Hardness Tester. Composite specimens were randomly placed in 20 mL of the selected mouthwashes (Colgate® Plax, Listerine® Teeth & Gum Defence, and Closeup® Antibacterial Mouthwash Cool Breeze) and stored in an incubator for 24 hours at 37 °C. Next, microhardness values were rechecked. pH measurements were recorded for each type of mouthwash using a digital pH meter. Due to the acidic nature of Colgate® and Listerine®, the microhardness of the restorations decreased with these mouthwashes; Listerine® caused the greatest decrease in microhardness and had the lowest pH reading (4.34). For Closeup®, with a neutral pH (7.02), no negative effect on microhardness was found; on the contrary, due to the presence of zinc in this latter mouthwash, an increase of the microhardness was found. We confirm the negative effect of acidic mouthwashes on the microhardness of composite dental restorations.