The Use of Fiber-Reinforced Composites for Restoration of Endodontically Treated Teeth: A Review

@#This review summarized the most recently published literature pertaining to the use of fiber-reinforced composite (FRC) to restore endodontically treated teeth (ETT) and its influence on the mechanical behavior of restored teeth. Indepth¬ literature review in Google Scholar, ScienceDirect and PubMed was performed for these keywords: “fiber-reinforced composite”; “fiber post”; “endodontically treated”; “short fiber-reinforced composite”— only published fulltext articles between 2009 and 2021 are included in this review. Fourteen articles were selected for this review. The studies concentrated on laboratory-based research conducted on human and bovine extracted teeth with different restorative techniques. Fatigue survival and load to failure tests with assessment of survival rate and fracture strength values respectively, as well as fracture pattern analysis were done. We concluded that FRC materials have improved fracture strength of restored teeth compared to conventional composites using different restorative techniques, however not to the attained level of an intact natural tooth. In addition, authors recommend a better simulation of oral environment, such as dynamic fatigue-testing.

Effects of fiber surface deposited with silicon dioxide films on properties of fiber-reinforced composites / 口腔医学

Objective@#To investigate the effects of fiber surface deposited with silicon dioxide films by atomic layer deposition on properties of dental fiber-reinforced composites.@*Methods @#SiO2 films were deposited on the surface of quartz fiber by atomic layer deposition(ALD). Then the quartz fiber was used to manufacture fiber resin composites, which were divided into four groups: A(no soaking agent removal), B(soaking agent removed), C(soaking agent removed and silanization), and D(soaking agent removed, 600 ALD cycles performed and then silanization). Scanning electron microscopy, water contact angle test, hygroscopicity test, CCK8 test and three-point bending test were used to investigate the properties of fiber resin composites.@*Results@#The surface morphology of the quartz fiber treated by ALD was smooth and had no obvious change compared with that before treatment. Moreover, the quartz fiber showed hydrophobicity after silanization. The results of three-point bending test revealed that the mechanical properties of fiber-resin composites modified by ALD were significantly improved(P<0.05). When viewed by scanning electron microscopy, a good interfacial bonding could be seen between quartz fibers and the resin matrix in Group D. In addition, it was found that Group D had low absorbability, low solubility and good biocompatibility. @*Conclusion@#It is shown that deposition of SiO2 films on the quartz fiber by ALD can significantly enhance the mechanical properties of fiber-reinforced composites.

Evaluation of fracture strength and total void amount in composite restorations on endodontically treated teeth / Resistencia a la fractura y la cantidad total de burbujas en resinas compuestas de dientes tratados endodónticamente

ABSTRACT: The aim of the study was to investigate the fracture strength of different composite resins and the quantity of voids in conventional posterior composite, high- flow flowable composite, bulk-fill flowable composite, and fiber-reinforced composite. Forty-four caries-free, freshly extracted mandibular premolars were used for this study. Teeth were prepared for cavity and root canal treatment. Subsequently, root canal treatment was applied to the teeth and cavities in order to prepare them for restorations. The specimens were then divided into four groups: group-1: Estelite Posterior; group-2: Estelite Flow Quick High Flow; group-3: Estelite Bulk-fill Flow; group-4: everX Posterior. One specimen from each experimental group was examined using micro-CT to perform measurement of voids. The fracture strength values of high-flow flowable, bulk-fill flowable, fiber-reinforced, and conventional micro- hybrid composites were found to be similar (p=0.497). EverX Posterior showed the highest fracture strength values (841.1±149.4 N), followed by Estelite Bulk-fill Flow (822.8±170.8 N). Volume of voids (%) obtained from Micro-CT analysis revealed that restorations with high-flow liner or bulk-fill flowable exhibited more voids. The fiber-reinforced composite showed the lowest percentage volume of incorporating voids and the highest fracture strength results.

RESUMEN: El objetivo del estudio fue investigar la resistencia a la fractura de diferentes resinas compuestas y la cantidad de burbujas en resinas posteriores convencionales, resinas fluidas de alto flujo, resinas fluidas tipo bulk-fill y resinas reforzados con fibras. Cuarenta y cuatro premolares mandibulares libres de caries, recién extraídos, fueron usados para este estudio. Los dientes se prepararon para el tratamiento de conductos radiculares y las cavidades para prepararlos para las restauraciones. Los especímenes se dividieron en cuatro grupos: Grupo-1: Estelite Posterior; Grupo-2: Estelite Flow Quick High Flow; Grupo-3: Estelite Bulk-fill Flow; Grupo-4: everX Posterior. Un espécimen de cada grupo experimental fue examinado usando micro-CT para realizar la medición de las burbujas. Los valores de resistencia a la fractura de los compuestos de alto flujo, flujo de relleno, reforzados con fibra y microhíbridos convencionales fueron similares (p=0,497). EverX Posterior mostró los valores más altos de resistencia a la fractura (841,1±149,4 N), seguido de Estelite Bulk-fill Flow (822,8±170,8 N). El volumen de las burbujas (%) obtenido del análisis de Micro-TC reveló que las restauraciones con revestimiento de alto flujo o con flujo de relleno a granel presentaban más huecos. El compuesto reforzado con fibra mostró el menor porcentaje de volumen de incorporación de vacíos y los resultados más altos de resistencia a la fractura.

Fracture Resistance of Teeth Restored with Bulk-Fill and Fiber-Reinforced Composites in Class II Cavities / Resistencia a la fractura de dientes restaurados con resinas de relleno y resinas reforzadas con fibra en cavidades clase II

ABSTRACT: This study aimed to evaluate the fracture resistance of teeth restored with conventional, bulk-fill, and fiber-reinforced composite materials regarding intact teeth. Standard cavities were prepared on 70 sound third molar teeth. The teeth were randomly divided into six groups: intact teeth, conventional Bis-GMA based composite, fiber-reinforced composite, Bis-GMA based bulk-fill composite, ormocer based bulk-fill composite, glass containing resin-based bulk-fill composite. The data was obtained by a Universal Testing Machine and analyzed statistically. Fracture resistance of the teeth restored with conventional composite was significantly lower than the other groups (p0.05). The obtained data showed that restoring teeth with bulk-fill and fiber-reinforced composites could be recommended in Class II cavities.

RESUMEN: El objetivo del presente estudio fue evaluar la resistencia a la fractura de los dientes restaurados con materiales compuestos convencionales, de relleno y reforzados con fibras, en relación con los dientes intactos. Se prepararon cavidades estándar en 70 dientes de terceros molares sanos. Los dientes se dividieron al azar en seis grupos: dientes intactos, compuesto convencional basado en Bis-GMA, compuesto reforzado con fibra, compuesto de relleno a base de Bis-GMA, compuesto de relleno a base de ormocer, compuesto de relleno a base de vidrio que contiene resina. Los resultados fueron obtenidos utilizando una máquina universal de pruebas y analizados estadísticamente. La resistencia a la fractura de los dientes restaurados con el composite convencional fue significativamente menor que la de los otros grupos (p0,05). Los datos obtenidos mostraron que la restauración de dientes con composites de relleno y reforzados con fibra podría ser recomendada en cavidades de Clase II.

Fiber-reinforced composite resin bridges: an alternative method to treat root-fractured teeth

The replacement of missing teeth, especially in the anterior region, is an essential part of dental practice. Fiber-reinforced composite resin bridges are a conservative alternative to conventional fixed dental prostheses or implants. It is a minimally invasive, reversible technique that can be completed in a single visit. The two cases presented herein exemplify the treatment of root-fractured anterior teeth with a natural pontic immediately after extraction.

Comparison of the interdiffusion of four self-etching adhesives in resin-aged glass-fiber-reinforced composites / 口腔疾病防治

Objective@#To observe the permeability of four kinds of self-etching adhesives in aged glass-fiber-reinforced composite (GFRC).@*Methods@#After light polymerization following the manufacturers’ instructions, a total of 80 pieces of bisphenol-A-glycodal-methacrylate (Bis-GMA)+ polymethyl methacrylate (PMMA) based GFRC were randomly divided into two main groups: test group and control group, each group was then divided into four subgroups with 10 samples for each subgroup. While the test group was conducted to be aged through thermocycling at 5 ℃/55 ℃, the control group remained fresh. After the addition of a fluorescent dye (rhodamine-B-isothiocyanate), four self-etching adhesives AdperEasy One (AEO), S 3 BOND (S 3B), Tetric N-Bond Self-Etch (TNB), G-Bond (GB) were correspondently applied to the test and control groups and were light polymerized. Specimens were sectioned using hard tissue cutting and grinding system. Slices from each subgroup were observed under a confocal laser scanning microscope, the depth of dye permeation (DDP) under the surface of GFRC in each group was measured and the Results were statistically analyzed.@*Results@#The DDP of AEO was the deepest (32.58 ± 6.06) μm, and that of TNB was the shallowest (6.19 ± 1.38)μm among the four self-etching adhesive subgroups in the control group. The order of each group was AEO > GB > S 3B > TNB. The DDP of the four subgroups in the test group was significantly shallower than that in the control group (P < 0.05). The change in GB was the greatest (9.05 ± 2.35)μm/(28.93 ± 5.32)μm. In the test group, the DDP in AEO was the deepest (28.42 ± 5.32)μm, and the DDP in TNB was shallowest (1.93 ± 0.22)μm again. The order of each group was AEO > S 3B > GB > TNB. In the test group, while the layer of fluorescent dye of AEO and S 3 B could still be seen distinctly, that of TNB and GB was hard to recognize. @*The DDP of AEO was the deepest (32.58 ± 6.06) μm, and that of TNB was the shallowest (6.19 ± 1.38)μm among the four self-etching adhesive subgroups in the control group. The order of each group was AEO > GB > S 3B > TNB. The DDP of the four subgroups in the test group was significantly shallower than that in the control group (P < 0.05). The change in GB was the greatest (9.05 ± 2.35)μm/(28.93 ± 5.32)μm. In the test group, the DDP in AEO was the deepest (28.42 ± 5.32)μm, and the DDP in TNB was shallowest (1.93 ± 0.22)μm again. The order of each group was AEO > S 3B > GB > TNB. In the test group, while the layer of fluorescent dye of AEO and S 3 B could still be seen distinctly, that of TNB and GB was hard to recognize. @#The self-etching adhesives of AEO and S 3 B still have good permeation effect in this kind of aged GFRC, which can help to establish a good bond between these aged GFRC and the subsequent repair of composite resin.

Fiber-Reinforced Composite Resin Fixed Partial Denture To Restore Missing Anterior Teeth: A Case Report

Prosthetic dentistry constantly evolving as a result of innovative treatment solution based on new material, treatment technique,and technologies. The advent of fiber reinforced has further increased the potential uses of composite material within prostheticdentistry. As we know that, missing anterior teeth are serious concern in the social life of a patient. To restore the missing anteriorteeth, we are having several treatment options such as conventional fixed partial denture and implant-supported restoration allthese are may the treatment of choice, but fiber-reinforced composite (FRC) resin offers a conservative, fast, and cost-effectivealternative for single or multiple teeth replacement. In this paper, we are presenting how to use FRC technology to restoreanterior edentulous area in terms of esthetic values and functionality.

Alternativa estética ante la pérdida de piezas primarias en el sector anterior: resolución clínica / Esthetic alternative to the loss of primary pieces in the previous sector

La pérdida de piezas permanentes en el sector anterior sigue siendo una preocupación clínica en el tratamiento odontológico de niños y adolescentes. Es importante destacar que la pubertad y la adolescencia son etapas donde las relaciones con los pares son de suma importancia. Las restauraciones protéticas convencionales no cumplen las expectativas estéticas, pero siguen siendo el tratamiento de elección, ya que los implantes solo pueden ser realizados una vez finalizados el crecimiento y el desarrollo. Los sistemas adhesivos mediante cinta de fibra de vidrio han simplificado el trabajo, brindando una alternativa intermedia conservadora y estética. El objetivo de este trabajo es presentar la resolución clínica en dos pacientes que concurrieron a la Cátedra de Odontología Integral Niños luego de haber sufrido traumatismos que provocaron la pérdida de piezas dentarias permanentes logrando la restitución de la longitud de arco, la devolución de la estética y la fonación con la colocación de una prótesis tipo Maryland, realizada con cinta de fibra de vidrio preimpregnada con resina compuesta (AU)

Premature loss of anterior permanent teeth is still a cause for concern in dental treatment of children and adolescents. Social relationships with peers are particularly important during puberty and adolescence. Removable prosthesis has always been a choice but they may not satisfy patients' esthetic expectations and dental implants can only be placed after the jaw has finished growing. Adhesive directly bonded splints with glass fibers reinforced composite resins can be an alternative to conventional space maintainers. The aim of this report is to describe the treatment of two patients who attended at the Department of Comprehensive Children´s Dentistry after suffering traumatic dental injuries using bridges as an approach to restore arch length, esthetics and function (AU)

Comparison between fiber-reinforced polymers and stainless steel orthodontic retainers / 대한치과교정학회지

OBJECTIVE: The aim of this study was to examine the properties of fiber-reinforced composite and stainless steel twisted retainers for orthodontic retention. METHODS: Three different span lengths (5.0, 8.0, and 14.0 mm) of fiber-reinforced composite were investigated. The three fiber-reinforced composite retainer groups were subdivided according to the storage condition (dry and wet), resulting in a total of six groups. Each stainless steel and fiber-reinforced composite group was comprised of six specimens. The three-point bending flexural test was conducted using a universal testing machine. ANOVA was used to assess differences in the maximum load and maximum stress according to the span length, material, and storage condition. Post-hoc comparisons were performed if necessary. RESULTS: The maximum stress and maximum load were significantly (p < 0.001) associated with the span length, material, and storage condition. The significant interaction between the material and span length (p < 0.001) indicated the differential effects of the material for each span length on the maximum stress and maximum load, with the difference between materials being the highest for the maximum span length. CONCLUSIONS: Our findings suggest that fiber-reinforced composite retainers may be an effective alternative for orthodontic retention in patients with esthetic concerns or allergy to conventional stainless steel wires.

Efecto del tratamiento de superficie en la fuerza de adhesión de postes de resina reforzados con fibras de cuarzo a los cementos de resina: Estudio in vitro

14. El propósito de este estudio fue determinar el efecto que ejercen distintos tratmientos de superficie en la fuerza de adhesión entre el cemento de resina y los postes de resina reforzados con fibras de cuarzo. Materiales y métodos: Sesenta postes de fibra de cuarzo (DT Light-Post™, Bisco™) se asignaron aleatoriamente a 12 grupos experimentales (n=5), según el cemento de resina utilizado (Biscem™ o Duolink™) y el tipo de tratamiento de superficie: limpieza con alcohol (grupo control), silanizado, primer, arenado, arenado+silanizado o arenado+primer. Se obtuvieron especímenes cilíndricos de resina utilizando resina nanohíbrida. Los postes se cementaron a los discos de resina y se sometieron a pruebas de push-out. Los datos se analizaron con ANOVA y prueba T para comparación de promedios y la prueba Tukey HSD con un nivel de significancia del 95%. Resultados: El cemento Biscem™ presentó, en general, una mayor fuerza de adhesión a los postes al compararse con el Duolink™. Se encontró diferencia significativa entre en grupo control y los grupos de arenado+silano y arenado+primer al utilizar el cemento Duolink™. Con el cemento Biscem™ no hubo diferencias entre grupos o con el grupo control. Conclusión: Los tratamientos de superficie en los postes de resina reforzados con fibra de cuarzo parecen no tener un efecto significativo en la fuerza de adhesión a los cementos de resina evaluados en este estudio, excepto al utilizar el cemento Duolink™ realizando el arenado y además se utilizando el silano o el primer.

18. The purpose of this study was to determine the effect of different surface treatments on the bond strength between resin cements and quartz fiber-reinforced resin posts. Materials and methods: Sixty quartz fiber-reinforced resin posts (DT Light-Post™, Bisco™) were randomly divided into 12 experimental groups (n=5), according to the resin cement used (Biscem™ or Duolink™) and the surface treatment: Alcohol (control group), silanized, primer, sandblasted, sandblasted + silanized or sandblasted + primer. Cylindrical resin specimens were obtained using nanohybrid resin. The posts were cemented to the resin discs and push-out tests were conducted. Data were analyzed with ANOVA and T test for averages comparison and the Tukey HSD test with a 95% level of significance. Results: Biscem™ cement generally showed higher bond strength when compared to Duolink™ Significant differences were found between the control group and the sandblasted + silane and sandblasted + primer groups when using Duolink™cement. With Biscem™ cement, no differences between groups or with the control group were found.. Conclusion: Surface treatments on quartz fiber-reinforced resin poles seem to have no significant effect on the bond strength to resin cements, except when using Duolink™ cement with sandblasted posts and using silane or primer.

Effects of different resin core materials on microleakage for post-core restorations / 西安交通大学学报(医学版)

Objective To compare the effects of different composite resins as core material on the degree of microleakage in post-core repairation.Methods A total of 46 recently extracted single-rooted mandibular premolars were distributed into different groups according to different core material including ParaCore,AP-X and Ceramage.Then we used direct or indirect forming method to make post-core restorations.All of the specimens were submerged in dyes.Then,they were demineralized,dehydrated and processed to be transparent.The extent of the dye leakage was examined under a stereomicroscope.Results The microleakage value was significantly higher in Group of direct-mold-cement with ParaCore (4.94± 1.71)mm than in Group of indirect-mold-secondary-cement with ParaCore (0.91 ± 0.33) mm,Group of indirect-mold-secondary-cement with AP-X (0.87 ± 0.27) mm,and Group of indirect-mold-secondary-cement with Ceramage (1.02 ± 0.34)mm.Conclusion Different methods of building and cementing FRC post-core restorations,but not different composite resins as core material,have significant effects on the extent of microleakage in post-core repair.

Clinical evaluation of retention strength of two different adhesive systems on glass fiber-reinforced posts / 口腔疾病防治

Objective@# To evaluate the clinical effect of two different resin cements on the glass fiber-reinforced posts.@*Methods @# One hundred and thirty-six teeth were randomly divided into two groups, with sixty-eight in each. Group A used Multilink N self-etch system and group B used RelyX Unicem self-adhesive system to bond fiber posts. Follow-up examinations took place at 6, 12 and 24 months after the placement. @*Results @#The success ratios of two groups were all 97% above and there was no significant difference between two groups (P > 0.05). @*Conclusion@#Multilink N self-etch system and RelyX Unicem self-adhesive system all have good effect on glass fiber-reinforced posts bonding.

Establishment of TMJ defect models and evaluation on repair effect of CFR-PEEK material artificial joint in rabbits / 吉林大学学报(医学版)

Objective:To investigate the method of arthroplasty for reconstructing femporomandibular joint (TMJ) after the establishment of TMJ articular defect models in the rabbits,and to clarify the replacement and repair effects of carboh fiber reinforced polyetheretherketone (CFR-PEEK) material TMJ prostheses,and to provide an experimental basis for the clinical application of CFR-PEEK artificial joints to replace TMJ.Methods:Thirteen healthy adult Japanese rabbits were randomly divided into experimental group (n=6),positive control group (n=4) and negative control group (n =3).The right TMJ articular process of the rabbits in experimental group were resected to establish the joint defect models,and then the CFR-PEEK artificial joints were impanted.The right TMJ articular process of the rabbits in positive control group were resected,and the joint defect models were established without the CFR-PEEK artificial joint implantation.The rabbits in negative control group didn't receive any treatment.The body weights of the rabbits in each group were measured in 13 weeks.The effects of fixation and replacement after artificial joint implantation were assessed by CT imaging.Results:The TMJ articular process defect model was successfully implanted with the CFR-PEEK artificial joint.The CT imaging results after threedimensional reconstruction and CT images by contrast in vitro showed that the CFR-PEEK-implanted artificial joint was fixed well,it could be instead of the normal joint function.Compared with positive control group,the weights of rabbits in experimental group were significantly increased (P＜ 0.05) at 13 weeks;compared with positive control group,the weights of rabbits in experimental group and negative control group were both significantly increased (P＞0.05) at 13 weeks,but there was no significant difference between them (P＞0.05).The weights of rabbits in experimental group and negative control group kept normal growth;the weights of rabbits in positive control group was increased slowly,and even stopped growing or was negative.Conclusion:The CFR-PEEK artificial joint can be successfully implanted into the TMJ defect model and be used to repair the defect which help to restore chewing function.The CFR-PEEK is expected to be an ideal material for reconstructing TMJ.

Establishment of TMJ defect models and evaluation on repair effect of CFR-PEEK material artificial joint in rabbits / 吉林大学学报(医学版)

Objective:To investigate the method of arthroplasty for reconstructing femporomandibular joint (TMJ) after the establishment of TMJ articular defect models in the rabbits,and to clarify the replacement and repair effects of carboh fiber reinforced polyetheretherketone (CFR-PEEK) material TMJ prostheses,and to provide an experimental basis for the clinical application of CFR-PEEK artificial joints to replace TMJ.Methods:Thirteen healthy adult Japanese rabbits were randomly divided into experimental group (n=6),positive control group (n=4) and negative control group (n =3).The right TMJ articular process of the rabbits in experimental group were resected to establish the joint defect models,and then the CFR-PEEK artificial joints were impanted.The right TMJ articular process of the rabbits in positive control group were resected,and the joint defect models were established without the CFR-PEEK artificial joint implantation.The rabbits in negative control group didn't receive any treatment.The body weights of the rabbits in each group were measured in 13 weeks.The effects of fixation and replacement after artificial joint implantation were assessed by CT imaging.Results:The TMJ articular process defect model was successfully implanted with the CFR-PEEK artificial joint.The CT imaging results after threedimensional reconstruction and CT images by contrast in vitro showed that the CFR-PEEK-implanted artificial joint was fixed well,it could be instead of the normal joint function.Compared with positive control group,the weights of rabbits in experimental group were significantly increased (P＜ 0.05) at 13 weeks;compared with positive control group,the weights of rabbits in experimental group and negative control group were both significantly increased (P＞0.05) at 13 weeks,but there was no significant difference between them (P＞0.05).The weights of rabbits in experimental group and negative control group kept normal growth;the weights of rabbits in positive control group was increased slowly,and even stopped growing or was negative.Conclusion:The CFR-PEEK artificial joint can be successfully implanted into the TMJ defect model and be used to repair the defect which help to restore chewing function.The CFR-PEEK is expected to be an ideal material for reconstructing TMJ.

Two-year survival analysis of twisted wire fixed retainer versus spiral wire and fiber-reinforced composite retainers: a preliminary explorative single-blind randomized clinical trial / 대한치과교정학회지

OBJECTIVE: Traditional retainers (both metal and fiber-reinforced composite [FRC]) have limitations, and a retainer made from more flexible ligature wires might be advantageous. We aimed to compare an experimental design with two traditional retainers. METHODS: In this prospective preliminary clinical trial, 150 post-treatment patients were enrolled and randomly divided into three groups of 50 patients each to receive mandibular canine-to-canine retainers made of FRC, flexible spiral wire (FSW), and twisted wire (TW). The patients were monitored monthly. The time at which the first signs of breakage/debonding were detected was recorded. The success rates of the retainers were compared using chi-squared, Kaplan-Meier, and Cox proportional-hazard regression analyses (α = 0.05). RESULTS: In total, 42 patients in the FRC group, 41 in the FSW group, and 45 in the TW group completed the study. The 2-year failure rates were 35.7% in the FRC group, 26.8% in the FSW group, and 17.8% in the TW group. These rates differed insignificantly (chi-squared p = 0.167). According to the Kaplan-Meier analysis, failure occurred at 19.95 months in the FRC group, 21.37 months in the FSW group, and 22.36 months in the TW group. The differences between the survival rates in the three groups were not significant (Cox regression p = 0.146). CONCLUSIONS: Although the failure rate of the experimental retainer was two times lower than that of the FRC retainer, the difference was not statistically significant. The experimental TW retainer was successful, and larger studies are warranted to verify these results.

Effect of different adhesive systems and post surface treatments on the push-out bond strengths of fiber-reinforced post / 대한치과보철학회지

PURPOSE: The purpose of this study was to evaluate the push-out bond strength of glass-fiber post cemented with different adhesive systems and surface treatments. MATERIALS AND METHODS: 160 tooth samples made from 48 human maxillary single-rooted teeth with similar root length were divided into 4 groups according to the adhesive system (no adhesive, Adper Single Bond 2, Clearfil SE Bond, Clearfil S3). Each group had 4 subgroups according to the post surface treatment methods (no treatment, sandblast, silane, sandblast and silane). Posts (Parapost Fiber White) were cemented with Rely X Unicem. The teeth were sectioned perpendicular to their long axis into 1-mm thick sections. The push-out tests was performed at a speed of 0.5 mm/min. The results were evaluated by 2-way ANOVA, 1-way ANOVA and multiple comparison procedures (Tukey test) (α=0.05). RESULTS: Tukey test showed that the adhesive system significantly influenced the push-out strength. The Clearfil SE Bond group showed the highest value. Post surface treatments showed no significant effect. CONCLUSION: Bond strength of glass-fiber post cemented with self-adhesive resin cement using Clearfil SE Bond showed significantly higher values compared to other adhesive systems.

Comportamiento clínico de prótesis fijas de resina compuesta reforzadas con fibra: evaluación a 5 años: resultados finales / Clinical behavior of fixed prostheses of fiber-reinforced composite: five-years follow-up: final results

El objetivo de este estudio fue evaluar parámetros clínicos en Prótesis Fijas de Resina Compuesta Reforzada con Fibra (PFs-RCRF), en pacientes de la Clínica de Prostodoncia Fija de la Universidad Católica del Uruguay. Se realizó un estudio observacional, longitudinal, analítico. Se seleccionaron 25 pacientes entre 18 y 65 años con ausencia de una pieza posterior y con antagonistas naturales, restaurados o no. Las PFsRCRF fueron realizadas por docentes, y estudiantes de 5° año bajo supervisión docente. Un observador calibrado (Kappa 0.88) controló cada 6 meses durante 5 años y evaluó tomando como referencia criterios de Ryge G (1980) simplificados. Se consideró Alfa (A: sin alteración), Beta (B: alteraciones que no requieren tratamiento) y Charlie (Ch: necesidad de reciclado o recambio). Se controló Tinción Marginal (TM), Integridad Marginal (IM), Superficie (S) y Color (C). Se hicieron 10 controles en 20 PFs-RCRF y los resultados promedio de los retenedores fueron: TM: A: 47,6%, B: 48,3%, Ch: 4,1%; IM: A: 33,6%, B: 61,8%, Ch: 4,6%; S: A: 62,4%, B: 32,5%, Ch: 5,1% C: A: 73,7%, B: 23,6%, Ch: 2,7%. Los resultados promedio de los pónticos fueron: S: A: 59,7%, B: 34,9%, Ch: 5,4%; C: A: 90,1%, B: 6,9%, Ch: 3%. Se concluye que las PFs-RCRF han demostrado en 5 años, ser una alternativa funcional, estética, rápida, reciclable, de bajo costo y relativamente buena confiabilidad. Son fáciles de remover y reemplazar si fuera menester. Son importantes los controles periódicos para el éxito de dichas estructuras.

The aim of the study was to assess clinical parameters in Fixed Prosthesis of Fiber-Reinforced Composite (FPs-FRC) in patients of Fixed Prosthodontic Clinic of the Universidad Católica del Uruguay. An observational, longitudinal and analytic study was carried out. Twenty-five patients between 18 and 65 years old with a missing posterior with natural antagonists restored or not, were selected. The FPs-FRC were produced by teachers, and 5th year students – teaching supervision. One calibrated observer (Kappa 0,88) controlled every 6 months during 5 years and assessed taking as reference the simplified criteria of Ryge G (1980). The following was considered: Alpha (A: no alteration whatsoever), Bravo (B: minor alterations not requiring treatment) and Charlie (Ch: recycling or replacement needed). Marginal Staining (MS), Marginal Integrity (MI), Surface (S) and Color (C) were controlled. Ten controls were made in 20 FPs-FRC and average results of retainers were as follows: MS: 47,6%, B: 48,3%, Ch: 4,1%; MI: A: 33,6%, B: 61,8%, Ch: 4,6%; S: A: 62,4%, B: 32,5%, Ch: 5,1%; C: A: 73,7%, B: 23,6%, Ch: 2,7%. Average results of pontics were the following: S: A: 59,7%, B: 34,9%, Ch: 5,4%; C: A: 90,1%, B: 6,9%, Ch: 3%. It is concluded that, FPs-FRC proved to be in 5 years, functional, aesthetic, quick, recyclable, low-cost and with relatively good reliability. They are easy to remove and replace if necessary. Periodic inspections are important for the success of these structures

Effect of Plasma and Fiber Position on Flexural Properties of a Polyethylene Fiber-Reinforced Composite

Abstract: The aim of this study was to evaluate the effect of plasma treatment using argon and oxygen gases, combined with fiber position on flexural properties of a fiber-reinforced composite. Eleven groups were evaluated, a non-reinforced control group and 10 groups reinforced with InFibra, a woven polyethylene fiber, varying according to the plasma treatment and fiber position. The samples were prepared using a stainless steel two-piece matrix. The three point bending test was performed in an EMIC testing machine. Flexural strength (FS) and flexural deflection (FD) were calculated from initial (IF) and final (FF) failure. Data were evaluated statistically using Kruskal-Wallis and Mann-Whitney tests (p<0.05). For IF, in all groups with fibers placed on the base, the FS and FD values were significantly higher than those positioned away from the base. The highest value of FS was obtained in the group treated with O 3 min (296.2 MPa) and the highest value of FD was obtained in the group treated with 1 min (0.109 mm). For FF the FS and FD values obtained for the groups with fibers positioned away from the base were similar or higher than those placed on the base. The highest FS value was obtained in the group treated with 1 min (317.5 MPa) and the highest FD value was obtained in the group treated with O 3 min (0.177 mm). Plasma treatment influenced FS and FD. Fiber position and plasma treatment affected the flexural properties of a fiber-reinforced composite.

Resumo O objetivo deste estudo foi avaliar o efeito do tratamento de plasma, utilizando os gases argônio e oxigênio, associado à posição da fibra, nas propriedades mecânicas de um compósito reforçado por fibra. Onze grupos foram avaliados, um grupo controle, sem reforço, e 10 grupos reforçados com Infibra, variando de acordo com o tratamento de plasma e a posição das fibra. As amostras foram preparadas utilizando uma matriz bipartida de aço inoxidável. O teste de flexão de três pontos foi realizado em uma máquina de ensaios EMIC. A resistência à flexão (FS) e deflexão (FD) foram calculados em relação à falha inicial (IF) e final (FF). Os dados foram avaliados estatisticamente pelos testes de Mann-Whitney e Kruskal-Wallis (p<0,05). Para IF, nas fibras posicionadas na base, os valores de FS e FD foram significativamente maiores do que quando as fibras foram afastadas da base em todos os grupos. O maior valor de FS foi obtido no grupo tratado com O 3 min (296,2 MPa) e o maior valor de FD foi obtido no grupo tratado com O 1 min (0,109 mm). Para FF, os valores de FS e FD para os grupos com fibras afastadas da base foram semelhantes ou superiores aos daqueles com fibras na base. O maior valor de FS foi obtido no grupo tratado com O 1 min (317,5 MPa) e o maior valor de FD foi obtido no grupo tratado com O 3 min (0,177 mm). O tratamento de plasma influenciou o FS e o FD. A posição de fibras, assim como o tratamento de plasma, afetaram as propriedades de flexão de um compósito reforçado com fibra.

Color stability of laboratory glass-fiber-reinforced plastics for esthetic orthodontic wires / 대한치과교정학회지

OBJECTIVE: In our previous study, glass-fiber-reinforced plastics (GFRPs) made from polycarbonate and glass fibers were prepared for esthetic orthodontic wires using pultrusion. These laboratory GFRP wires are more transparent than the commercially available nickel-titanium wire; however, an investigation of the color stability of GFRP during orthodontic treatment is needed. Accordingly, in the present study, the color stability of GFRP was assessed using colorimetry. METHODS: Preparation of GFRP esthetic round wires (diameter: 0.45 mm [0.018 inch]) using pultrusion was described previously. Here, to investigate how the diameter of fiber reinforcement affects color stability, GFRPs were prepared by incorporating either 13-microm (GFRP-13) or 7-microm glass (GFRP-7) fibers. The color changes of GFRPs after 24 h, and following 1, 2, and 4 weeks of coffee immersion at 37degrees C, were measured by colorimetry. We evaluated the color stability of GFRPs by two evaluating units: the color difference (DeltaE*) and National Bureau of Standards (NBS). RESULTS: After immersion, both GFRPs showed almost no visible color change. According to the colorimetry measurements, the DeltaE* values of GFRP-13 and GFRP-7 were 0.73-1.16, and 0.62-1.10, respectively. In accordance with NBS units, both GFRPs showed "slight" color changes. As a result, there were no significant differences in the DeltaE* values or NBS units for GFRP-13 or GFRP-7. Moreover, for both GFRPs, no significant differences were observed in any of the immersion periods. CONCLUSIONS: Our findings suggest that the GFRPs will maintain high color stability during orthodontic treatment, and are an attractive prospect as esthetic orthodontic wires.

Fracture resistance of upper central incisors restored with different posts and cores

OBJECTIVES: To determine and compare the fracture resistance of endodontically treated maxillary central incisors restored with different posts and cores. MATERIALS AND METHODS: Forty-eight upper central incisors were randomly divided into four groups: cast post and core (group 1), fiber-reinforced composite (FRC) post and composite core (group 2), composite post and core (group 3), and controls (group 4). Mesio-distal and bucco-lingual dimensions at 7 and 14 mm from the apex were compared to ensure standardization among the groups. Twelve teeth were prepared for crown restoration (group 4). Teeth in other groups were endodontically treated, decoronated at 14 mm from the apex, and prepared for posts and cores. Resin-based materials were used for cementation in groups 1 and 2. In group 3, composite was used directly to fill the post space and for core build-up. All samples were restored by standard metal crowns using glass ionomer cement, mounted at 135degrees vertical angle, subjected to thermomechanical aging, and then fractured using a universal testing machine. Kruskal-Wallis and Mann-Whitney U tests were used to analyze the data. RESULTS: Fracture resistance of the groups was as follows: Control (group 4) > cast post and core (group 1) > fiber post and composite core (group 2) > composite post and core (group 3). All samples in groups 2 and 3 fractured in restorable patterns, whereas most (58%) in group 1 were non-restorable. CONCLUSIONS: Within the limitations of this study, FRC posts showed acceptable fracture resistance with favorable fracture patterns for reconstruction of upper central incisors.