Fill Resin Research Articles

What is the clinical evidence of Bulk Fill resins performance of in primary and permanent teeth? a systematic review and meta-analysis

With the increasing acceptance of the clinical use of bulk-fill resins, it is necessary to investigate the in vivo performance of these restorative materials. In this perspective, this systematic review to evaluate the clinical performance of Bulk-fill resins in restorations of vital, primary and permanent posterior teeth. PubMed, Cochrane, Scopus, LILACS, BBO and Capes publications search base were searched without restriction regarding the year of publication or language of the article. The inclusion criteria were clinical trials that evaluated the efficacy of resins composed of bulk-fill compared to the incremental technique. For the selection of articles and data extraction, two calibrated evaluators evaluated abstracts and complete articles. A total of 1443 abstracts were identified, of which 14 articles were included in the review. Of these, 01 was classified with a high level of evidence; 08 were moderate and 05 with a low level of evidence. The studies presented an average follow-up of the restorations of 35.1 months. A large part of the studies (75%) demonstrated that the occurrence of postoperative sensitivity. The high failure rate was more prevalent in class II restorations. The marginal adaptation/color change was material dependent and the occurrence of secondary caries in bulk-fill resin restorations was not significant concerning conventional resins in most studies. In the short term, the satisfactory clinical performance of bulk-fill resins used in primary and permanent restorations, with clinical outcomes and results equivalent to conventional composite resins were observed.

Direct composite resin fillings versus amalgam fillings for permanent posterior teeth.

Direct composite resin fillings versus amalgam fillings for permanent posterior teeth.

Influence of Filler Composition on the Refractive Index of Four Different Enamel Shades of Composite Resins

The purpose of this study was to measure the refractive index of four commercially available enamel resin composites, using optical coherence tomography (OCT) and their relationship with the atomic composition of the composite resin fillers utilizing an energy-dispersive X-ray fluorescence spectrometer (EDX). Four different enamel composites, namely Enamel HRi color UE3, Enamel HFO color GE3, Vit-l-escence color Pearl Frost, and Amelogen Plus color Enamel White were tested. For each composite, disks with different thicknesses were fabricated and then light-cured according to the manufacturer's instructions. The disks were then stored in deionized water under 36.5 °C for at least 7 days. Each of the samples from the four different groups was measured in five distinctive points to analyze the optical and physical length using optical coherence tomography (OCT). Elemental analysis of all four different enamel shades of the composite was done using an EDX. The filler contents showed interesting differences in elemental composition and concentration; however, Si seemed to be a common filler component. The HRi composite presented a distinctive composition compared to other materials and was the only composite that showed a smaller percentage of SiO2, and also was the only composite that contained compounds, such as P2O5, ZnO, CaO, La2O3, and V2O5. The optical coherence tomography analysis showed the refractive index values of all tested enamel composites. Among the four different enamel composite resins tested, the enamel HRi composite demonstrated the most ideal refractive index to mimic natural enamel. The enamel HRi composite demonstrated a distinctive filler composition and this could be the main reason behind its higher refractive index. Nonetheless, it remains unclear how much of an impact this feature has in the final esthetic outcome of anterior composite restorations, where many other optical phenomena are also important. The clinical success of any esthetic restorative procedure depends on diagnosing the proper treatment plan and also on executing this treatment with the right materials. On direct esthetic restorations, knowing the optical properties of such materials is fundamental, as they should be able to replicate both natural enamel and dentin. How to cite this article: Beolchi RS, Mehta D, Pelissier B, et al. Influence of Filler Composition on the Refractive Index of Four Different Enamel Shades of Composite Resins. J Contemp Dent Pract 2021;22(5):557-561.

Desirability of Tribo-Performance of Natural Based Thermoset and Thermoplastic Composites: A Concise Review

Tribology, which may be defined as an interdisciplinary subject, deals with relative motion between two or more bodies, i.e., surfaces that are interacting relatively. Thus, tribology is a science covering three vital classes, namely, 1) wear, 2) friction, and 3) lubrication. The focus of this article is to bring out the elements that are influencing the wear-resisting behavior of thermosetting and thermoplastic composites with natural-based constituents. It was also identified from the literature sources that 1) the treatments on the natural fibers acting as reinforcement and 2) the addition of fillers in resin acting as matrix could improve the wear-resisting behavior of the composites. Additionally, other conditions such as 1) sliding speed, 2) sliding velocity, 3) sliding distance, and 4) operating temperature could also influence the friction coefficient and specific wear rate of the natural-based composites.

Evaluation of heated air jet on pulp chamber temperature at different steps of the restorative protocol

Objectives: Evaluate of the heated air jet temperature (T) in the pulp chamber on cavity 5 depths and photoactivation stages for a bulk fill resin restorative protocol is evaluated. Methods: Class I cavity preparations were conducted at different depths (n = 8) through two protocols for adhesive volatilization (23 °C and 40 °C) and cavities were restored with the Filtek Bulk Fill resin. The pulp chamber temperature variation was evaluated at four steps (times) during the restorative protocol: I (initial), V (after volatilization), A (after photoactivation of the adhesive), and C (after photoactivation of the composite resin). To verify the assumptions of the normality of the errors and homoscedasticity, the Shapiro Wilk and Levene tests were conducted. Subsequently, two-way and three-way analysis of variance was carried out, followed by Tukey's post-hoc analysis (α = 0.05). Results: The maximum T at the different restorative steps, regardless of the volatilization protocol and cavity depth, was as follows: I (36.8 °C) = V (36.9 ºC) < A (37.2 °C) = R (37.8 ºC) (p <0.05). During V, a small greater variation was observed in pulp chamber temperature when dentin was volatilized at 40 °C (p <0.05) at very deep cavity depths (0.31 °C). The largest temperature variations (p <0.05) were observed during A (0.17–0.59 °C) and R (0.50–1.06 °C), reaching peak temperatures in the cavities.

Numerical Investigation for the Resin Filling Behavior during Ultraviolet Nanoimprint Lithography of Subwavelength Moth-Eye Nanostructure

Accurate analysis of the resin filling process into the mold cavity is necessary for the high-precision fabrication of moth-eye nanostructure using the ultraviolet nanoimprint lithography (UV-NIL) technique. In this research, a computational fluid dynamics (CFD) simulation model was proposed to reveal resin filling behavior, in which the effect of boundary slip was considered. By comparison with the experimental results, a good consistency was found, indicating that the simulation model could be used to analyze the resin filling behavior. Based on the proposed model, the effects of process parameters on resin filling behavior were analyzed, including resin viscosity, inlet velocity and resin thickness. It was found that the inlet velocity showed a more significant effect on filling height than the resin viscosity and thickness. Besides, the effects of boundary conditions on resin filling behavior were investigated, and it was found the boundary slip had a significant influence on resin filling behavior, and excellent filling results were obtained with a larger slip velocity on the mold side. This research could provide guidance for a more comprehensive understanding of the resin filling behavior during UV-NIL of subwavelength moth-eye nanostructure.

The fabrication and anticorrosive performances of sulfonate‑barium@sulfonated graphene composite filler

Graphene material has been used as a superior protection barrier for metal surface due to its excellent impermeability to corrosive electrolyte. However, it is not satisfactory for long-term corrosion resistance of graphene, which has a tendency to agglomerate in the resin coating. In this study, a novel anticorrosion filler was fabricated by sulfonated graphene (GS) sheets wrapping sulfonate‑barium (BS) nanoparticles. The composite material (BS@GS) exhibited a flake-like structure with numerous BS nanoparticles (particle size of 20–50 nm) on the sheet surface. The introduction of BS@GS filler in epoxy resin coating could significantly enhance corrosion resistance of carbon steel. For instance, when added only 4 wt% of BS@GS filler, the impedance modulus at 0.01 Hz of composite coating was still maintained as 1.576 × 105 Ω cm2 after immersion in NaCl solution for 168 h, about 2 orders of magnitude higher than pristine resin coating. It demonstrated that this work developed an effective strategy to achieve long-term anticorrosion application for the graphene material.

Single-Lap Joints Bonded with Epoxy Nanocomposite Adhesives: Effect of Organoclay Reinforcement on Adhesion and Fatigue Behaviors

Organoclay, such as organo-modified montmorillonite (MMT), is one of the potential filler candidates in the preparation of epoxy nanocomposite adhesives for automotive and civil engineering industries. However, there is no systematic research on the effect of organoclay reinforcement on its adhesion and fatigue behaviors in shear loading. Here, single-lap joints (SLJs) of stainless steel substrates bonded with epoxy/MMT nanocomposite adhesives, consisting of diglycidyl ether of bisphenol A and poly(oxypropylene) diamine with various weight contents of a commercialized MMT filler, were prepared. The dispersity of MMT and bulk mechanical properties were investigated by wide-angle X-ray scattering/diffraction, the uniaxial tensile test, and dynamic mechanical analysis. The lap shear strengths and failure modes were investigated based on the single-lap shear test, and the joint durability was examined by using the fatigue test with various shear stress levels. Through the incorporation of the MMT fillers in epoxy resins, the lap shear strengths increased from 25 to 40 MPa, the failure modes changed from adhesive failure mode to cohesive one, and the fatigue lifetimes prolonged with the addition of a small amount of MMT.

Evaluation of mechanical properties of novel GLARE laminates filled with nanoclay

AbstractIn this research work, we have investigated the effect of nanoclay fillers in the epoxy adhesive on improving the interfacial adhesion and the mechanical properties of glass‐reinforced aluminum laminates. The laminates were prepared with a varying weight percentage of nanoclay fillers (i.e., 3, 4, and 5 wt%) in the epoxy resin using the hand lay‐up method. During the tensile test, the laminate's anisotropic nature was investigated using the samples cut in different orientations to the rolling direction (i.e., 0, 45, and 90°). The flexural, lap shear, and impact tests were conducted as per ASTM standards. After each test, the failure mechanisms of laminates were studied using the scanning electron microscope. The results showed that 3 wt% of nanoclay added in the epoxy enhanced the laminates' overall mechanical properties than other composites. The fiber metal laminates (FML) containing the nano clay more than 3 wt% showed deterioration in the mechanical property due to the improper distribution of nanoclay in the epoxy matrix. The FML's mechanical properties with nano clay filler were compared with other fillers' performance in the previous studies. It was found that the mechanical properties of FML with nano clay filler were more significant than others.

THE COMPARISON OF RESIN-BASED COMPOSITES PHYSICAL PROPERTIES BETWEEN BULK-FILL TECHNIQUE AND INCREMENTAL TECHNIQUE

ABSTRACT:Composite resins are currently the most popular restorative material in dentistry. This is due to good aesthetics and maximum conservation ability. Behind these advantages, there are disbenefits of composite resin materials, such as polymerization shrinkage, which can lead to restoration failure. Various attempts have been investigated to reduce the shrinkage incidence of composite resins, one of which is the technique of placing the restorative material into the cavity. The restoration filling technique is recognized as a significant factor in shrinkage stress. By using a special filling technique, the polymerization shrinkage damage stress can be reduced. There are several techniques in performing composite resin fillings, including bulk and incremental techniques. These techniques have their respective advantages and disadvantages. The aim of this literature review was to compare the physical properties of composite resin restorations with bulk filling and incremental techniques. Physical properties that being studied include polymerization shrinkage, stress shrinkage, degree of conversion, bonding strength, water resorption, color stability, and temperature increase. Comparing the two techniques, composite resin with incremental filling technique has superior physical properties compared to bulk technique. From the comparison of the two techniques, the composite resin with incremental filling technique has superior physical properties compared to the bulk technique, especially in higher conversion which causes lower shrinkage stress. This situation makes the incremental technique provide better bond strength, water resorption, color stability, and lower temperature rise.Keywords: Bulk, Composite Resin, Incremental, Physical Properties, Restoration, Restoration Technique

EFEITO DO ACABAMENTO E POLIMENTO SOBRE A TOPOGRAFIA SUPERFICIAL DE UMA RESINA COMPOSTA CONVENCIONAL E UMA BULK FILL

Introdução: Os compostos resinosos são materiais bastante presentes no dia a dia da clínica odontológica. Apesar de suas vantagens e ótimas propriedades, as resinas compostas convencionais ainda apresentam limitações, como o maior tempo clínico e falhas na adesão. Dessa forma tem-se o surgimento das resinas Bulk-Fill que entre as suas vantagens e propriedades temos: menor tempo clínico, baixa contração de polimerização, maior translucidez, além de propriedades que levam a sua melhor manipulação, tempo clínico e topografia superficial. Objetivo: Avaliar a topografia superficial de restaurações realizadas com diferentes tipos de resina composta antes e após submetê-las a diferentes sistemas de acabamento e polimento. Metodologia: Foram confeccionados 100 corpos de prova (CP), sendo 50 de cada composto resinoso, apresentando cinco grupos (n=10) sorteados de forma aleatória, de acordo com o sistema de acabamento e polimento (AP) empregado. Foram utilizadas as resinas Filtek Z350 XT (3M ESPE, St. Paul, MN, EUA) e a Bulk Fill Filtek One Bulk Fill (3M ESPE, St. Paul, MN, EUA) e os sistemas de acabamento e polimento: Discos de Lixa Sof-Lex Pop On Kit (DL); Discos Diamantado Espiral Sof-Lex (DE); Ponta Enhance (PE) e Broca Carbide Multilaminada nº 0283F (BM), que foram comparados com superfície deixada pela Tira de Poliester (Controle Negativo – CN). Após 7 dias de armazenamento em água destilada, os CP foram submetidos a análise da superfície por meio do Microscópio Eletrônico de Varredura (MEV). Resultados: Os CP da resina Bulk Fill tiveram como melhor resultado o sistema de AP com BM e resultado não satisfatório com DE, enquanto o PE e DL tiveram resultados semelhantes. Os CP da resina Filtek Z350 XT tiveram melhor aspecto visual de lisura superficial no grupo CN e pior resultado no grupo com DE. Conclusões: Dessa forma, o sistema que apresentou melhor resultado foi com a BM na resina Bulk Fill, enquanto a Filtek Z350 XT apresentou-se melhor no grupo C. Porém, ainda são necessários mais estudos que possam levar em considerações outras variações na metodologia empregada para se chegar em um protocolo de acabamento e polimento mais eficiente.

Influence of gamma irradiation on the restorative interface and surface morphology of bulk fill dental composites

Objective: The purpose in this in vitro study was to evaluate the influence of gamma irradiation on the marginal integrity and surface morphology of bulk fill resin composites by Microcomputed tomography (μ-CT) and Scanning Electron Microscopy (SEM). Methods: class I cavities (3 mm deep) were prepared in 60 third molars restored with the following resin composites: Filtek™ Bulk Fill (FBF), TetricEvoCeram Bulk Fill (TBF), X-tra Fil Bulk Fill (XTA) and Filtek™ Z350 (Z350) (n = 15). The samples were immersed in 50% silver nitrate solution, scanned and subdivided according to the gamma radiation doses (Control group – no radiation, 30 and 60 Gy). After irradiation, the teeth were again immersed in silver nitrate and scanned. For morphological analysis, 12 cylindrical (10 x 2mm) specimens were and submitted to the studied radiation regimens (n =4). Data were analyzed by the Kruskal-Wallis and Fisher LSD tests (α = 0.05). Results: it was observed that the irradiation negatively affected the marginal integrity of samples restored with FBF (p < 0.05). No significant differences were observed for the other resin composites. No changes were shown in the surface morphology of bulk fill composites, despite irradiation having affected the surface morphology of the control group (Z350). It was concluded that the accumulated doses of 30 and 60 Gy negatively affected the tooth-restoration interface of FBF and at the surface morphology of Z350. Conclusions: TetricEvoCeram, and X-tra Fil Bulk Fill resin composites can be considered alternatives in the restorative treatment of patients submitted to radiotherapy of the head and neck.

Preparation of mesoporous coal gasification slag and applications in polypropylene resin reinforcement and deodorization

Here, we have prepared a novel mesoporous powder (CGSF3) from coal-gasification fine slag. The specific surface area and pore volume of CGSF3 were 564 m2 g−1 and 0.807 cm3 g−1, respectively. Furthermore, CGSF3 was introduced into polypropylene (PP) to prepare PP composites. When the filler content was 30 wt%, the tensile, impact, and flexural strengths of the PP-CGSF3 composite were 49.84%, 70.81%, and 139.63% higher than those of the conventional PP-CaCO3 composites, respectively. More significantly, the total amount of volatile organic compounds (VOCs) volatilized from PP-CGSF3 was 67.6% less than that of neat PP, far exceeding the performance of zeolite deodorant filler. The strength of this work is that the high-performance and low-cost mesoporous resin fillers can be prepared from solid wastes.

Comparative Evaluation of Microhardness and Compressive Strength of Cention N, Bulk Fill Resin Composite and Glass Ionomer Cement

Objective: Evaluation of microhardness and compressive strength of Cention N in comparison to nanohybrid bulk fill resin composite and glass ionomer cement (GIC). Methodology: A total of 30 specimens were prepared for microhardness evaluation, divided into three key groups of ten specimens each depending on the type of bulk fill restorative material used; Cention N, Tetric Evo Ceram bulk fill resin composite and Fuji IX GP groups. Specimens were prepared using a specially constructed 4 mm thickness cylindrical Teflon mold with a diameter of 6 mm. All specimens were stored in distilled water at room temperature for 24 hours then subjected for Vickers microhardness tester. Assessment of compressive strength of the tested restorative materials necessitates fabrication of 30 specimens with a diameter of 3mm and 6mm thickness (ten specimens each). Universal testing machine was used for evaluation of compressive strength of all tested materials. Results obtained were subjected to one-way ANOVA and Tukey’s HSD test (P values of 0.05). Results: Both microhardness and compressive strength tests results showed that there was no significant difference between Tetric EVO Ceram and Cention N (p < 0.001), meanwhile both of them are significantly higher than Fugi IX GP. Conclusions: Under the limitation of the current study, the bioactive composite Cention N is a promising bulk fill resin composite restoration in the posterior region in terms of tested mechanical properties. Key words: Cention N, bulk fill resin composite, GIC, microhardness, compressive strength.

A New Method of Diatomaceous Earth Fractionation-A Bio-Raw Material Source for Epoxy-Based Composites.

The authors of this paper use an original method of diatomaceous earth fractionation, which allows for obtaining a filler with a specific particle size distribution. The method makes it possible to separate small, disintegrated and broken diatom frustules from those which maintained their original form in diatomaceous earth. The study covers a range of tests conducted to prove that such a separated diatomic fraction (3–30 µm) shows features different from the base diatomite (from 1 to above 40 µm) used as an epoxy resin filler. We have examined the mechanical properties of a series of diatomite/resin composites, considering the weight fraction of diatoms and the parameters of the composite production process. The studied composites of Epidian 601 epoxy resin cross-linked with amine-based curing agent Z-1 contained 0 to 70% vol. of diatoms or diatomaceous earth. Samples were produced by being casted into silicone molds in vacuum degassing conditions and, alternatively, without degassing. The results have shown that the size and morphology of the filler based on diatomaceous earth affects mechanical and rheological properties of systems based on epoxy resin. Elongation at rupture and flexural stress at rupture were both raised by up to 35%, and impact strength by up to 25%.

Investigation of adhesive wear properties of glass fiber reinforced polyester composites having different chemical compositions

Glass fiber reinforced polyester composite materials are widely used in various areas due to their high specific strength, low weight, excellent elasticity, high corrosion resistance, and high thermal stability. This study aims to investigate the effects of resin materials and various fillers and wear parameters such as different loads and speeds on the tribological properties of glass fiber reinforced polyester composite materials. In this experimental study, various resins (tensile additive orthophthalic polyester and plain orthophthalic polyester), fillers (alumina and glass beads), and reinforcing materials were used during the sample preparation. The samples were subjected to an adhesive wear test at two different speeds ( n = 100 r/min and n = 200 r/min) and different loads ( F = 10 N and F = 20 N) at 150 m sliding distance. The friction coefficient and friction force were measured by the tribometer. The thickness of the wear trace was later measured and the wear rate was calculated. Wear surfaces of samples were visualized with a three-dimensional laser profilometer in order to obtain surface topographies and surface roughness values. The sample surfaces were examined by scanning electron microscopy in order to understand the wear mechanisms and to characterize the morphology of worn surfaces. Experimental results have shown that alumina or glass beads fillers can reduce the average friction coefficient when used in the correct amounts. The use of glass bead filler in orthophthalic polyester resin with tensile additive is more effective than reducing the wear rate compared to alumina filler. The load on the wear behavior of glass fiber reinforced polyester composite materials is more effective than the speed.

Effects of different surface treatments and adhesive self-etch functional monomers on the repair of bulk fill composites: A randomised controlled study

ObjectiveTo evaluate the effect of different adhesive protocols on the microtensile bond strength (μTBS) and integrity of the repaired bulk fill composite interface. MethodsTwo hundred and seventy composite blocks made of bulk fill composites of different viscosity were randomly assigned to 18 surface conditioning groups (n = 15/group). The universal adhesive systems used were Heliobond™, Tokuyama bond force II™ and Scotchbond Universal™. A nanohybrid resin composite was applied as the repair material. Negative and positive control groups were included. Stick shape specimens of each group were subjected to μTBS testing. Representative samples from all test groups were subjected to microscopic, profilometric and SEM examination to determine their mode of failure. The data were analysed statistically using two-way ANOVA test, Tukey’s test and the independent t-test (α = 0.05). ResultsThe mean μTBS of all test groups ranged between 28.5 and 46.8 MPa and varied with the type of adhesive system employed. Significantly highest μTBS values were obtained when Tokuyama bond force II™ and Scotchbond Universal™ adhesives were used (p < 0.01) which were comparable to the coherent strength of the bulk fill resin composite in the positive control groups (p > 0.05). The viscosity of the bulk fill composite did not significantly influence repair bond strength. The microscopy and SEM examination of the failed interfaces revealed a mixture of adhesive and cohesive failures. ConclusionsUnder the tested conditions, significantly greater μTBS of repaired bulk fill composite was achieved when the substrate surface was treated with adhesive systems containing a functional monomer. Clinical significanceEff ;ecting a repair of a bulk fill resin composite restoration with the application of a functional monomer containing adhesive system, such as Tokuyama Bond Force II™ or Scotchbond Universal™, would seem to enhance the interfacial bond strength and integrity of the repaired resin composite interface.

Polymerization shrinkage and shrinkage stress development in ultra-rapid photo-polymerized bulk fill resin composites

ObjectiveTo determine the polymerization shrinkage (%) and shrinkage stress (MPa) characteristics of ultra-rapid photo-polymerized bulk fill resin composites. MethodsTwo ultra-rapid photo-polymerized bulk fill (URPBF) materials: PFill and PFlow were studied, along with their comparators ECeram and EFlow. PFill contains an addition fragmentation chain transfer (AFCT) agent. The URPBR materials were irradiated using two different 3 s high irradiance protocols (3000 and 3200 mW/cm2 based on Bluephase PowerCure and VALO LCUs, respectively) and one 10 s standard protocol (1200 mW/cm2 based on a Bluephase PowerCure LCU). Bonded disk and Bioman II instruments were used to measure Polymerization shrinkage % and shrinkage stress MPa, respectively, for 60 min at 23 ± 1 °C (n = 5). Maximum shrinkage-rate and maximum shrinkage stress-rate were also calculated for 15 s via numerical differentiation. The data were analyzed via multiple One-way ANOVA and Tukey post-hoc tests (α = 0.05). ResultsPFill groups, regardless of their irradiance protocol, showed significantly lower PS than the comparator, ECeram (p < 0.05). However, PFlow irradiated via different protocols, was comparable to EFlow and ECeram (p > 0.05). PFill consistently produced stress results which were significantly lower than ECeram (p < 0.05) and were comparable for both high irradiance protocols (p > 0.05). PFlow only exhibited significantly higher shrinkage stress when polymerized with the 3 sVALO protocol (p < 0.05).The maximum shrinkage strain-rate (%/s) was significantly lower in PFill-10s and PFill-3s groups (using PowerCure LCU) compared to ECeram. However, no differences were seen between PFlow and EFlow (p > 0.05). The maximum shrinkage stress-rate of PFill and PFlow was comparable between different irradiation protocols, as well as to their comparator ECeram (p > 0.05). SignificanceHigh irradiation protocols over ultra-short periods led to slightly lower shrinkage strain but slightly higher stress, possibly due to reduced network mobility. The AFCT agent incorporated in PFill composite seemed to reduce shrinkage stress development, even with high irradiance protocols.

Clinical Fracture of Fiber Reinforced Resin Composite Versus Conventional Resin Composite Restorations in Endodontically Treated Molars: A Randomized Clinical Trial

Background: Short fiber reinforced resin composite (Ever X Posterior) is a bulk fill resin compositeindicated as a core dentine substitute at high stress-bearing areas improve strength and fracture toughness ofconventional resin composite and restored teeth. So, this randomized clinical trial was conducted to validateclinical performance of short fiber reinforced resin composite in endodontically treated molars.Method: 56 participants having endodontically treated lower molars with moderate amount of remainingtooth structure were randomly enrolled in this trial and received either Ever X Posterior covered by Gaenialposterior or only Gaenial posterior resin composite that applied according to manufacturer instructions.Mann-Whitney U test was used for intergroup comparisons and Wilcoxon signed rank test was used forintragroup comparisons. The significance level was set at p ? 0.05. No statistically significant difference wasobserved between both tested groups for all USPHS criteria at different follow-up periods except for colormatch favoring Gaenial posterior with a significant difference between both groups.Conclusion: Both types of restorations showed an acceptable clinical performance along 1 year follow-upperiod.

CLINICAL EVALUATION OF THE NANO HYBRID BULK FILL COMPOSITE AND NANO HYBRID FLOWABLE COMPOSITE IN CLASS I RESTORATIONS--- AN IN VIVO STUDY

Objectives: The aim of this study was to evaluate the clinical performance of a nano filled flowable and nano hybrid bulk fill resin composite in class I restorations.&#x0D; Methods and Materials: Twenty patients were selected for this in vivo study. Each patient received at least one pair of restorations, restored with nano hybrid bulk fill resin composite (IPS Empress direct [IED]) and nano hybrid Tetric N Ceram flowable composite [TNC]. Each restorative resin system was used with its respective adhesive system according to manufacturers’ instructions.&#x0D; A total of 40 class I restorations were placed by one operator. Restorations were blindly evaluated by two examiners at baseline and 3, 6, and 12 months respectively using modified US Public Health Service Ryge criteria.&#x0D; The data obtained was statistically analyzed using Chi square test to compare the two restorative materials for each category.&#x0D; Results: At 3, 6 and 12, months, recall rate was 100%, 95% and 85%, respectively, with a retention rate of 100%. There were statistically significant differences between the two restorative resins in terms of marginal adaptation and marginal discoloration (p&lt;0.05).&#x0D; No differences were observed between the restorative resins in terms of retention (p&lt;0.05). None of the restorations showed postoperative sensitivity, or loss of anatomic form.&#x0D; Conclusion: Within the limitations of this study, nano hybrid bulk fill composite resin viz. IPS EMPRESS DIRECT showed better clinical performance than nano filled flowable composite in terms of marginal discoloration and marginal adaptation.&#x0D; Keywords: direct composite, bulk, hybrid filled resin