Use Of Composite Resin Research Articles

Short communication: Influence of restorative material and cement on the stress distribution of posterior resin-bonded fixed dental prostheses: 3D finite element analysis

The goal of this study was to compare the mechanical response of resin-bonded fixed dental prosthesis (RBFDP) made in zirconia, metal, lithium disilicate and composite resin cemented using resin cements with different elastic modulus. For the finite element analysis, a three-dimensional model of partial right maxilla was used to create a model with edentulous space in the second premolar and the cavity's preparation on the first pre-molar and first molar to receive a RBFDP. The model was imported to the analysis software in which they were divided into mesh composed by nodes (371,101) and tetrahedral elements (213,673). Each material was considered isotropic, elastic and homogeneous. No-separation contacts were considered between restoration/resin cement and resin cement/tooth. For all other structures the contacts were considered ideal. The model fixation occurred at the base of the bone and an axial load of 300 N was applied on the pontic occlusal surface. To simulate polymerization shrinkage effects on the cement, the thermal expansion approach was used. The displacement and maximum principal stress (in MPa) were selected as failure criteria. The prosthesis made in composite resin showed higher displacement, while in zirconia showed higher stress concentration. Tensile stress between restoration/cement, cement and cement/cavity was directly proportional to the restorative material's elastic modulus. The more rigid cement increases the tensile zones in the cement layer but decreases the stress between prosthesis and cement. The molar cavity showed higher stress concentration between restoration/cement than the preparation in the pre-molar tooth. The use of composite resin for the manufacturing of RBFDP increases the displacement of the set during the loading. However, it reduces the amount of stress concentration at the adhesive interface in comparison with the other materials.

In Vitro Efficacy of Listerine Whitening Mouthwash for Color Recovery of Two Discolored Composite Resins.

Objectives:Color stability of composite resins has a significant role in their durability and clinical service. Considering the increasing use of composite resins and their gradual discoloration, this study aimed to assess the efficacy of Listerine whitening mouthwash for color recovery of two discolored composite resins.Materials and Methods:This in-vitro experimental study was performed on 20 samples fabricated of Filtek Z350XT (3M ESPE, St. Paul, MN, USA) and IPS Empress Direct (Ivoclar Vivadent, Schaan, Liechtenstein) composite resins. Primary colorimetry was performed using a spectrophotometer. The samples were immersed in a coffee drink for 7 days. They were then immersed in Listerine mouthwash for 4 minutes daily for 56 days. After this period, the color change of composite resins was reevaluated. Data were analyzed using repeated-measures analysis of variance (ANOVA) and t-test.Results:The primary color change of Z350XT after immersion in coffee was 1.6 times greater than that of IPS composite (P<0.0001). The color recovery of IPS and Z350XT after immersion in the mouthwash was 1.06±0.58 (P<0.01) and 2.58±1.65 (P<0.001) units, respectively. The color change of Z350XT after exposure to the mouthwash was 25% (1.4 times) greater than that of IPS (P<0.01).Conclusion:Both composite resins experienced a clinically unacceptable discoloration after exposure to coffee (ΔE>3.3). Filtek Z350XT showed greater color change than IPS. Use of Listerine whitening mouthwash caused significant color recovery in both composite resins.

Comparative evaluation of surface roughness of novel resin composite Cention N with Filtek Z350 XT: In vitro study

Aim: The aim of this study was to evaluate and compare the surface roughness of Cention N and Filtek Z350 XT resin composite. Null Hypothesis: There is no difference observed in surface roughness between the Cention N and Filtek Z350 XT resin composite. Introduction: The use of resin composites in restorative dentistry has markedly increased in recent years due to increased demand for esthetics. The advent of novel fluoride-releasing resin composite Cention N has brought enormous benefits. Finishing and polishing of composite resin restorations are essential steps in restorative dentistry. However, there are no studies available in literatures regarding the effective use of Soflex finishing and polishing with Cention N. Hence, the purpose of the study was to evaluate the surface roughness of novel resin composite Cention N and compare with Filtek Z350 XT resin composite. Materials and Methods: Sixty-four specimens were prepared in Teflon plastic mold of 8-mm diameter and 2-mm thickness, and were divided into group 1 (Filtek Z350 XT [n = 32]) and group 2 (Cention N [n = 32]). They were further subdivided into group 1A (Matrix finish [n = 16]) and 1B (Soflex [n = 16]), and group 2A (Matrix finish [n = 16]) and 2B (Soflex [n = 16]). Surface roughness was measured using surface profilometer. Results: When comparing the mean values and standard deviations of surface roughness of four groups using one-way ANOVA, it was found that there was a significant difference (P < 0.001) in mean surface roughness between the four groups. Conclusion: All the groups presented the values that are below or approximating baseline value for bacterial or plaque retention.

Evaluation of the surface microhardness of composite resins. Literature review.

At present, the use of composite resins has increased considerably, becoming the main restorative material used by dentists, both for the anterior and posterior sectors. Among its properties, we find the hardness, which is a very important part to determine its durability in the mouth. This property is determined by the amount of filler that the resin presents, therefore, the greater the amount of filler, the greater its hardness and smaller dimensional changes. Despite all the improvements in technology and properties of composite resins, there is still no material that has ideal characteristics that make it indestructible over the years. The objective of this article is to review the main characteristics of composite resins, especially surface microhardness. Hardness is a condition of the surface of a given material, it does not represent any property of the material and is related to the elastic and plastic properties of each material. There are currently many systems to measure hardness, for example, Brinell, Rockwell, Vickers and Knoop systems.

Esthetic Management of Maxillary Midline Diastema (MMD) using Composite Restoration: A Case Report

Treatment of a Maxillary Midline Diastema (MMD) poses a challenge to the clinician, especially when time is a constraint. The use of composite resins provide a conservative approach with minimal tooth loss is less time consuming, and requires fewer dental visits. The present case report describes the closure of MMD in a patient using bulk filled composite resins with favourable results.

The antibacterial, cytotoxic, and flexural properties of a composite resin containing a quaternary ammonium monomer

Statement of problemThe use of composite resin to restore teeth has increased substantially during the last decades. However, secondary caries and the fracture of restorations are the leading reasons for clinical restoration failure. Mechanically strong composite resins with caries-inhibition capabilities are needed. Although antibacterial dimethacrylate quaternary ammonium monomers have been synthesized, composite resin containing dimethacrylate quaternary ammonium monomers and glass fillers has rarely been reported. PurposeThe purpose of this in vitro study was to evaluate the possibility of the clinical use of an experimental composite resin containing urethane dimethacrylate quaternary ammonium compound (UDMQA-12) by investigating its antibacterial activity, cytotoxicity, flexural strength, and flexural modulus. Material and methodsAntibacterial activity against Streptococcus mutans was investigated by means of direct contact test. The antibacterial activity of specimens after water immersion and saliva treatment was also tested. These were compared with a commercially available composite resin, Z250, and a glass ionomer cement, Fuji VII. Effects of the eluent from the experimental composite resin on the metabolic activity of human dental pulp cells were quantified. Disks of 1 mm in thickness and 15 mm in diameter were used in the antibacterial and cytotoxic tests. Flexural strength and flexural modulus were measured with a 3-point bend test with bars of 2×2×25 mm. Three commercially available composite resins (Filtek Z250, G-aenial Anterior, and G-aenial Posterior) were used as controls in the flexural test. ResultsBacterial growth was inhibited on the experimental composite resin. After water immersion or saliva treatment, the experimental composite resin showed significant antibacterial effect compared with the conventional composite resin (P<.05). No significant difference was found in cytotoxicity between the experimental composite resin and the conventional composite resin (P＞.05), and a significantly higher cytotoxicity was shown by glass ionomer cement compared with the experimental composite resin and the conventional composite resin (P<.05). The conventional composite resin had the highest flexural strength and flexural modulus (P<.05), followed by the experimental composite resin, then G-ænial Posterior and G-ænial Anterior. ConclusionsThe antibacterial experimental composite resin was biocompatible and had mechanical properties similar to those of some commercially available composite resins. It might, therefore, be useful in preventing the occurrence of secondary caries.

Ten-year follow-up on adoption of endodontic technology and clinical guidelines amongst Danish general dental practitioners

Objective: The aim of this study was to re-assess the adoption of certain endodontic technology and central treatment principles of root canal treatments as advocated by guidelines presented by the European Society of Endodontology.Material and methods: The questionnaire included the same questions in 2003 and 2013. The general dental practitioners (GDPs) anonymously reported how frequent (‘often’, ‘occasionally’, and ‘never’) they used certain endodontic technology and adhered to central treatment principles. The statistical analyses were performed using Chi-squared test and Goodman–Kruskal’s γ-coefficient as an association measure.Results: The overall response rate of the 2013 group was 46.5% (n = 531). The frequencies of GDPs reporting often use of rubber dam, apex locator and rotary NiTi instruments were significantly higher (p < .0001) than in 2003, as well as reporting the use of composite resin for coronal sealing (p < .019). Adoption was significantly influenced by the factors gender (p = .601) and time since graduation (p = .361), and the cluster analyses revealed the neglected use of rubber dam to be associated with no established postoperative recall system.Conclusions: After 10 years, there was a higher frequency of GDPs who had adopted certain endodontic technologies. However, progress towards high-quality root canal treatment might be obstructed as the majority of GDPs avoids consistent use of rubber dam, and routinely neglects recalls for postoperative controls of their endodontic treatments.

The evaluation of surface sealants' effect on the color stability of Nano-hybrid composite after polishing with One-Step system (in-vitro).

BackgroundThe clinical use of composite resins has increased substantially over the past few years due to increased esthetic demands by patients, improvements in formulation, and simplification of bonding procedures. An alternative for preventing or reducing composite discoloration is using of composite surface sealant. The purpose of this study was to determine the effect of surface sealant on color-stability of Nano-hybrid composites after polishing with one-step system.Material and Methods56 disk-shaped specimens (10*2 mm) of a Nano-hybrid composite resin (VOCO,Cuxhaven,Germany) were prepared. The specimens were randomly divided in to 2 groups of 28 specimens each. The surfaces of specimens were polished with One-step system (Dimanto,VOCO,Germany ). one group of specimens assigned as control group and received no more surface treatment .surface sealant (PermaSeal,Ultradent,USA) was applied on the surface of specimens of the other group as experimental group .specimens were stored in Ringer’s solution for 24 hours at 37oC. The specimens were subjected to artificial aging with thermocycling method between coffee solution at 55°C and Ringer’s solution at 5°C for 3000 cycles. CIE L*a*b color coordinates were established using a spectrophotometer for each specimen. Statistical significance was set at p<0.05.ResultsAfter aging in both groups, color changing was significantly different (p<0.05) and clinically unacceptable (ΔE> 3.3) and there was no significant difference between the two groups in ΔE.ConclusionsSurface sealant was not effective in improving color stability. Key words:Surface-penetrating Sealant, Color Stability, Nano-hybrid composites.

The evaluation of surface sealants' effect on the surface roughness of Nano-hybrid composite after polishing with One-Step system (in-vitro).

BackgroundThe clinical use of composite resins has increased substantially due to increased esthetic demands by patients, improvements in formulation, and simplification of bonding procedures. Use of surface sealants is recommended to improve surface smoothness of composite restorations. The aim of this study was to evaluate the effect of surface sealants on the surface roughness of nano-hybrid composite after polishing with One-Step system.Material and MethodsUsing a silicon mold, 56 specimens of 10 mm diameter and 2 mm height were prepared from Grandio nano-hybrid composite (Voco, Cuxhaven, Germany) with A2 shade. Specimens were randomly divided in 2 groups. The surface of specimens were polished with VOCO One-step system. One group of specimens assigned as control group and received no more surface treatment. Surface sealant PermaSeal (Ultradent, USA) was applied on the surface of specimens of the other group as experimental group. Specimens were stored in Ringer’s solution at 37°C for 24 hours. The specimens were subjected to artificial accelerated aging with thermocycling method (3000 cycles, between 5 and 55°C) and then 100000 cycles of tooth brushing. A Profilometer was used to measuring the surface roughness of specimens before and after aging procedures.ResultsThe surface roughness changes of control group were significant before and after aging (P<0.05). The mean final surface roughness of control group was unacceptable clinically while it was acceptable in experimental group.ConclusionsThe use of surface sealants on nano-hybrid composite causes noticeable reduces in surface roughness of composite. Key words:Surface-penetrating sealant, surface roughness, nano-hybrid, composites, one-step polishing.

Multidisciplinary Treatment Approach of a Patient with Amelogenesis Imperfecta Superimposed by Thumb Sucking Habit: A Case Report

A seven-year-old boy was presented with discontent of his teeth appearance, mild teeth sensitiveness, bad masticatory effectiveness, difficulty in speech and low self-esteem. The clinical and radiographic results indicated amelogenesis imperfecta. Because of uncooperative behavior, treatment was accomplished under general anesthesia. The use of composite resin and stainless steel crowns produced effective and satisfying improvement of the patient’s aesthetic looks, in addition to prevention of further sensitivity and wear so enhancing his functional needs. The lastingness of the thorough management of this patient needed powerful stress on careful oral hygiene. There is a major role of multidisciplinary team to the effective management of patients with hypomaturation type of amelogenesis imperfecta. Many factors have a significant part in treatment planning of amelogenesis imperfecta cases such as patient’s age, socioeconomic condition, seriousness of the defect, the patient’s collaboration and association with other medical conditions.

In-vitro cytocompatibility of dental resin monomers on osteoblast-like cells

ObjectivesDental resin-based materials are widely used in modern dentistry. Especially, resin cements enjoy great popularity and are utilized in many applications. Nevertheless, monomers could be released from the resinous matrix, thus interact with surrounding tissues, cause adverse biological reactions and may lead in cases of implant retained restorations to peri-implant bone destruction. Hence, we performed an in-vitro study to determine cytotoxicity of resin monomers on osteoblast-like cells. MethodsThree permanent osteoblast-like cell lines from tumor origin (MG-63 and Saos-2) as well as immortalized human fetal osteoblasts (hFOB 1.19) were used and treated with different concentrations of the main monomers: BisGMA, UDMA, TEGDMA and HEMA. The impact on cell viability was monitored using three different cytotoxicity tests: alamarBlue, XTT, and LDH assay. Mean±SEM were calculated and statistical analysis was performed with GraphPad Prism software. ResultsAll monomers tested caused concentration dependent cytotoxic effects on the three investigated osteoblast-like cell lines. Although all three cell viability assays showed comparable results in cytotoxic ranking of the monomers (BisGMA > UDMA > TEGDMA > HEMA), higher differences in the absolute values were detected by the various test methods In addition, also a cell line dependent influence on cell viability could be identified with higher impact on the immortalized hFOB 1.19 cells compared to both osteosarcoma cell lines (MG-63, Saos-2). ConclusionsMonomer concentrations detected in elution studies caused toxic effects in osteoblast-like cells. Although the results from in-vitro studies cannot be directly transferred to a clinical situation our results indicate that released monomers from composite resin cements may cause adverse biological effects and thereby possibly lead to conditions favoring peri-implantitis and bone destruction. Clinical significanceThe wide use of composite resin cements especially in implant-prosthetic treatments should be scrutinized to avoid possible clinical implications between eluted resin monomers and bone cells leading to conditions favoring peri-implantitis and bone destruction.

A survey of pediatric dentists' caries-related treatment decisions and restorative modalities - A web-based survey.

ObjectiveTo identify current practices and the preferred caries-related treatment decisions and restorative modalities of primary teeth among pediatric dental practitioners in Saudi Arabia.Materials and methodsThis was a web-based cross-sectional survey conducted among licensed pediatric dental practitioners in Saudi Arabia. Following the retrieval of the email addresses from the Saudi Dental Council, an email explaining the purpose of the study and a link to SurveyMonkey electronic survey consisting of 23 questions was sent to all the members registered under the pediatric dentistry practitioners, starting in September till December 2013. The data obtained was analyzed using descriptive statistics and chi square with and without tabulation processes. The level of significance was set at p < 0.05.ResultsA total of 108 [54 (50%) male and 54 (50%) female] pediatric dental practitioners responded to the survey out of 308 targeted individuals for an overall response rate of 35.1%. About 65% of the respondents reported that they have never considered pre-veneered or Zirconia crowns as a restorative option for carious vital anterior primary teeth. About 40% reported doing pulpectomy and restored with composite strip crowns at all times. About 86% of the respondents reported doing pulpotomy and stainless steel crown for restoring carious vital posterior primary teeth whereas 73.8% reported restoring with composite resin. However, 83.1% of the respondents reported that they never used pre-veneered or Zirconia crowns after pulpotomy for restoring carious vital posterior primary teeth. A significantly higher number of male participants reported that they used esthetic pediatric crowns in their practice compared to female participants (p < 0.001).ConclusionThe prevalence of use of composite resin to restore primary teeth was higher compared to glass ionomer cements and amalgam whereas a limited use of esthetic pediatric crowns was found among the sample surveyed. Esthetic pediatric crowns were more utilized by male compared to female participants.

Restaurarea directă a leziunilor carioase proximale cu ormoceri şI adezivi universali – prezentare de caz clinic

Introduction. Patients increased aesthetic requirements have determined the use of composite resins for the restoration of posterior proximal lesions. But one of their defects is the high polymerization shrinkage. Admira Fusion is the first “nano-ORMOCER” made by Nano-hybrid technology and ORMOCER (ORganic MOdified CERamic) which have a 50% lower polymerization shrinkage compared to conventional composite materials, also lower contraction stress, high surface hardness and marginal resistance. Futurabond U is a universal adhesive which associated with Admira Fusion accomplishes a restoration with aesthetic and functional performances. Case presentation. The patient presented for aesthetic restoration of tooth 45 which showed no painful pathology. For the restoration, Admira Fusion (Voco) and Futurabond U (Voco) were chosen and applied according to minimally invasive direct adhesive technique and for compaction, Compothixo instrument was used. Conclusions. The material and the work method have led to the achievement of a restoration that satisfies the aesthetic and functional principles.

Indirect Resin Composite Restorations Fabricated With Chairside CAD/CAM Systems

Aesthetics has gained significant importance in restorative dentistry besides the potential requirements including the continuity and integrity of tissue and regaining the function and phonation. The demand for esthetic posterior restorations gave way to the use of resin composites in the posterior region as well as the anterior restorations. However, polymerization shrinkage of resin composites limits this application to only with small sized restorations. In order to eliminate the disadvantage of polymerization shrinkage, various methods have been suggested to improve the properties and application methods of resins with the aim of increasing the longevity and function of restorative materials. For this purpose, computer aided design/computer aided manufacturing (CAD/CAM) systems have been used for the past 10 years to fabricate indirect restorations with resin composites as an alternative material in digital system. This review aims to provide an update on the resin composite materials used with indirect restorations and CAD/CAM systems.

Evaluation of Polymerization shrinkage of 2 types of posterior composite resins

AbstractComposite resins represent a class of material widely used in restorative dentistry, not only for anterior aesthetics but also as the first choice to restore posterior teeth. However the key limitation in the use of composite resins as a restorative material is related to shrinkage during polymerization which leads to poor marginal seal, marginal staining, restoration displacement, tooth fracture and recurring caries [1].Polymerization shrinkage may affect negatively the clinical outcome of the restoration. Hence the present study evaluates the Polymerization shrinkage of 2 different posterior composites; Filtek Z350(3M) and everX Posterior(GC), using a pycnometer.Independent Sample T-Test was used to determine statistically significant difference in volumetric shrinkage among the tested composite resins. everX Posterior showed comparatively less shrinkage than Filtek Z350; which can be attributed to the presence of silanated e-glass fibres.

The concepts of minimally invasive dentistry and its impact on clinical practice: a survey with a group of Dentists in Saudi Arabia

Objectives: the study was conducted to assess the associations between the demographic characteristics of participating dentists in Saudi Arabia and their restorative decisions for occlusal and proximal lesions. Their knowledge regarding caries diagnosis and management was assessed also. Materials and Methods: this is a cross-sectional study directed toward dentists practicing in Saudi Arabia. An online survey consisted of occlusal and proximal caries lesions. Results: For occlusal caries lesion the majority of dentists (48%) recommended removal of carious tissue when it is confined to enamel. A significant difference was found between dentists who are dealing with dental caries and other dentists. They recommend the use of composite resin for their first caries stage that requires treatment. For proximal lesions, females significantly (p=0.003) chose to restore the tooth at more advanced stage than males, composite was the first restorative material to be chosen for proximal lesions. Conclusion: The restorative decision for dentists practicing in Saudi Arabia were similar to other parts of the world. Occlusal caries lesions were easier to detect and to decide when and how to restore them. Female dentists were more towards minimally invasive dentistry than males in their decisions.

A simplified restorative technique of fractured maxillary anterior teeth

Fractures of the anterior teeth consists of a clinical condition that generates not only aesthetic and psychological problems, but may also cause dental pain. Thus, the affected teeth should be treated as urgencies in dental offices and their resolution whenever possible should be in a single session. Direct resin composite restorations should wherever possible be preferred due to the speed and possibility of obtaining good results. Objective: The objective of this case report is to describe the clinical sequence for restoration of a maxillary central incisor that presented a crown fracture using an immediate insert technique for resin composite (a free hand technique) with a modification to obtain dentin layer. Case report: A patient sought treatment after she fractured tooth #21. The restoration was performed with resin composite using the immediate technique. To facilitate the layering technique, the immediate insertion technique was changed for making the dentin lobes with the aid of a Teflon tape and the support with the index finger. Conclusion: The restoration of fractured anterior teeth can be performed quickly with the use of resin composites of different opacities and the use of the technique of immediate insertion proposed in this case report.

Variations in survival time for amalgam and resin composite restorations: a population based cohort analysis.

To estimate the association between the restorative material used and time to further treatment across population cohorts with universal coverage for dental treatment. Cohort study of variation in survival time for tooth restorations over time and by restoration material used based on an Accelerated Failure Time model. Primary dental care clinics. Members of Canada's First Nations and Inuit population covered by the Non-Insured Health Benefits program of Health Canada for the period April 1, 1999 to March 31, 2012. Tooth restorations using resin composite or amalgam material. Survival time of restoration to further treatment. Median survival time for resin composite was 51 days longer than amalgam, for restorations placed in 1999-2000. This difference was not statistically significant (p⟩0.05). Median survival times were lower for females, older subjects. Those visiting the dentist annually, and decreased monotonically over time from 11.2 and 11.3 years for resin composite and amalgam restorations respectively placed in 1999-2000 to 6.9 and 7.0 years for those placed in 2009-10. Resin composite restorations performed no better than amalgams over the study period, but cost considerably more. With the combination of the overall decrease in survival times for both resin composite and amalgam restorations and the increase in use of resin composite, the costs of serving Health Canada's Non-Insured Health Benefits population will rise considerably, even without any increase in the incidence of caries.

A simplified restorative technique of fractured maxillary anterior teeth

Fractures of the anterior teeth consists of a clinical condition that generates not only aesthetic and psychological problems, but may also cause dental pain. Thus, the affected teeth should be treated as urgencies in dental offices and their resolution whenever possible should be in a single session. Direct resin composite restorations should wherever possible be preferred due to the speed and possibility of obtaining good results. Objective: The objective of this case report is to describe the clinical sequence for restoration of a maxillary central incisor that presented a crown fracture using an immediate insert technique for resin composite (a "free hand" technique) with a modification to obtain dentin layer. Case report: A patient sought treatment after she fractured tooth #21. The restoration was performed with resin composite using the immediate technique. To facilitate the layering technique, the immediate insertion technique was changed for making the dentin lobes with the aid of a Teflon tape and the support with the index finger. Conclusion: The restoration of fractured anterior teeth can be performed quickly with the use of resin composites of different opacities and the use of the technique of immediate insertion proposed in this case report.

Splinting of teeth following trauma: a review and a new splinting recommendation.

With advances in the understanding of healing processes of the periodontium, pulp and alveolar bone following various injuries, the role of splinting has become relatively well defined. This is generally reflected in the guidelines for trauma management published by the International Association of Dental Traumatology. While the widespread use of composite resin as an adhesive in various functional/flexible splinting systems has over many years allowed ease of application, removal of the material is not only time consuming but more seriously accompanied by minor or major iatrogenic damage to enamel. Dental materials science has continued to provide new materials and amongst them the development of resin activated glass-ionomer cement suitable for orthodontic bracket cementation has allowed the development of an alternative simplified splinting regimen for traumatized teeth which offers ease of application and removal with minimal or no iatrogenic damage to enamel.