Bond strengths of resin cements to fiber-reinforced composite posts

PURPOSE: To evaluate the bond strengths of six different luting cements to fiber-reinforced composite (FRC) posts after various pre-treatment procedures. METHODS: 180 FRC posts were divided into three groups (n=60) and received the following surface treatments. Group 1: untreated control; Group 2: silane treatment; Group 3: CoJet treatment. The posts of each group were fixed with six different luting cements. Push-out tests were performed to determine the bond strengths between the cements and the fiber posts. RESULTS: The observed bond strengths (MPa) of the different resin cements to the posts were significantly affected by the type of cement (P< 0.001), but not by the pre-treatment chosen (P> 0.05; 2-way-ANOVA). Without consideration of the pre-treatment procedures, Clearfil showed the highest bond strengths, followed by Panavia F and RelyX, whereas Multilink, Variolink and PermaFlo showed significantly lower bond strength values (P< 0.05; Tukey's B).     

Flexural properties of three kinds of experimental fiber-reinforced composite posts

The aim of this study was to estimate the flexural properties of three kinds of experimental fiber-reinforced composite (FRC) posts and to evaluate their potential use as posts. Experimental FRC posts were fabricated with glass, aramid, and UHMWP fibers. Commercial FRC posts were used for comparison. A three-point bending test was performed at a crosshead speed of 1 mm/min. Experimental glass fiber posts showed significantly higher flexural strengths and moduli than aramid and UHMWP posts. Experimental UHMWP posts demonstrated superior toughness to the commercial posts. The glass fiber posts displayed stiff, strong and brittle features, while the UHMWP posts were flexible, weak and ductile. The flexural properties of the aramid posts fell between those of the glass and UHMWP posts. In conclusion, the glass fiber posts proved excellent in flexural strengths and moduli. However, the superior toughness of UHMWP fibers suggests the possibility of their use as posts in combination with glass fibers.     

Creep and dynamic viscoelastic behavior of endodontic fiber-reinforced composite posts

PurposeFiber-reinforced composite (FRC) posts have gained much interest recently and understanding of their viscoelastic properties is important as they can be used in stress-bearing posterior restorations. The aim of this study was to evaluate the creep behavior and the viscoelastic properties of four commercial FRC posts under different temperatures and different storage conditions.MethodsThe FRC posts tested were Glassix, C-Post, Carbonite and Snowlight. For the creep measurements a constant load below the proportional limit of the posts was applied and the angular deformation of the specimens was recorded. The viscoelastic parameters were determined by using dynamic torsional loading under four different conditions.ResultsAll materials were susceptible to creep and exhibited linear viscoelastic behavior. Residual strain was observed in all FRC posts. The viscoelastic properties were affected by the increase of temperature and water storage (p < 0.001) resulting in their decline. Carbon fiber posts exhibited better performance than glass fiber posts.ConclusionsFRC posts exhibit permanent strains under regular masticatory stresses that can be generated in the oral cavity. Their properties are susceptible to changes in temperature, while direct contact with water also affects them deleteriously.     

Adhesion between prefabricated fiber-reinforced posts and different composite resin cores: a microtensile bond strength evaluation

PURPOSE: The aim of this study was to evaluate the bond strengths between various resin composites used as core materials (Multicore Flow, Ivoclar-Vivadent; Tetric Flow, Ivoclar-Vivadent; Filtek Flow, 3M-ESPE; Tetric Ceram, Ivoclar-Vivadent; Filtek Z250, 3M-ESPE), and an FRC post (FRC Postec Plus, Ivoclar-Vivadent) by means of the microtensile nontrimming technique. MATERIALS AND METHODS: Five experimental groups were used. For the microtensile nontrimming technique, 45 to 50 beam-shaped specimens per group were obtained from cylinders of core material, which had been built up around the post by progressively adding small increments of composite resin. Each specimen was loaded in tension until failure at either one of the two post/core interfaces present in each stick. The differences in interfacial bond strength amongthe groups were tested for statistical significance with the one-way ANOVA test, followed by the Dunnett test for post-hoc comparisons. RESULTS: The measured bond strengths in MPa were 17.29 +/- 6.02 for FRC+MultiCore Flow, 16.37 +/- 6.92 for FRC+Tetric Flow, 13.14 +/- 5.35 for FRC + Filtek Flow, 12.38 +/- 4.34 for FRC + Tetric Ceram, and 10.75 +/- 5.43 for FRC + Filtek Z250. The statistical analysis revealed that MultiCore Flow achieved significantly higher bond strengths than Filtek Flow (p = 0.03), Tetric Ceram (p < 0.001), and Filtek Z250 (p < 0.001). The bond strength of Tetric Flow was significantly higher than that of Filtek Z250 (p = 0.003). CONCLUSION: For core buildup on a fiber post, dual-cure composites appear to be preferable to light-curing composites.     

Replacement of a tooth with a fiber-reinforced direct bonded restoration

Today's methods and materials for tooth replacement are multiple and varied. Modern materials now allow for highly conservative abutment preparations that can retain bonded single tooth replacement fixed prostheses. A case report is presented in which fiber reinforced with composite resin was used for placement of a three-unit fixed long-term provisional restoration, providing fracture resistance while achieving an esthetically pleasing, durable restoration.     

Influence of fabrication techniques on retention force of fiber-reinforced composite posts

The purpose of this study was to compare the retention force of FRC posts which were built up using direct and direct-indirect fabrication techniques with two fiber-reinforced core build-up systems (FibreKor and i-TFC). Posts were cemented in endodontically treated bovine single roots with resin cement using either direct or direct-indirect technique. Following which, the retention force of post-and-cores and fracture sites were examined. It was found that both the retention force and fracture site depended on the fabrication technique and resin cements. Post-and-cores built up with direct-indirect technique had greater retention force than those fabricated using direct technique. Fracture modes most frequently observed were adhesive failure at Resin/Dentin interface, a mixture of adhesive failures at Post/Resin and Resin/Dentin interfaces as well as cohesive failure of resin cements. Based on the results of this study, we concluded that when it comes to post-and-core build-up for endodontically treated tooth, the direct-indirect technique is more effective than the direct technique on the retention force of FRC posts.     

Load-bearing capacity of human incisor restored with various fiber-reinforced composite posts

Objectives

The aim of this study was to evaluate the load-bearing capacity and microstrain of incisors restored with posts of various kinds. Both prefabricated titanium posts and different fiber-reinforced composite posts were tested.

Methods

The crowns of human incisors were cut and post preparation was carried out. The roots were divided into groups: (1) prefabricated serrated titanium posts, (2) prefabricated carbon fiber-reinforced composite posts, (3) individually formed glass fiber-reinforced composite posts with the canal full of fibers, and (4) individually formed “split” glass fiber-reinforced composite posts. The posts were cemented and composite crowns were made. Intact human incisors were used as reference. All roots were embedded in acrylic resin cylinders and stored at room temperature in water. Static load was applied under a loading angle of 45° using a universal testing machine. On half of the specimens microstrain was measured with strain gages and an acoustic emission analysis was carried out. Failure mode assessment was also made.

Results

The group with titanium posts showed highest number of unfavorable failures compared to the groups with fiber-reinforced composite posts.

Significance

With fiber-reinforced composite posts the failures may more often be favorable compared to titanium posts, which clinically means repairable failures.     

Clinical evaluation of teeth restored with quartz fiber-reinforced epoxy resin posts

PURPOSE: This prospective clinical follow-up evaluated the acceptability of quartz fiber-reinforced epoxy posts used in endodontically treated teeth over a 30-month period. MATERIALS AND METHODS: In 132 patients, 180 endodontically treated teeth were restored using AEstheti-Plus quartz-fiber posts. The posts were luted with the All-Bond 2 adhesive system and C&B Resin Cement according to the manufacturer's recommendations. The core was made with Core-Flo or Bis-Core, and all-ceramic crowns or metal-ceramic crowns were applied as final restorations. The parameters considered as clinical failure were displacement, detachment, or fracture of posts; core or root fracture; and crown or prosthesis decementation. Patients were reevaluated at 6, 12, 24, and 30 months. RESULTS: One cohesive failure involving a margin of the composite core was observed after 2 weeks, and two adhesive fractures were seen after 2 months. These failures were located between the cement and the dentin walls of the canals. All three failures occurred during removal of the temporary crown. The percentage of failures was thus 1.7% over a 30-month period, but it was possible to successfully replace the restoration in all three failed cases. CONCLUSION: Over a 30-month period, the rehabilitation of endodontically treated teeth using quartz-fiber posts showed good clinical results. No crown or prosthesis decementation was observed, and no post, core, or root fractures were recorded.     

Survival rates of endodontically treated teeth restored with fiber-reinforced custom posts and cores: a 97-month study

PURPOSE: This study aimed to assess the long-term survival rates of polyethylene fiber-reinforced posts and cores used in endodontically treated teeth over a 97-month period. MATERIALS AND METHODS: Sixty-nine patients from a private dental office who underwent endodontic treatment with coronoradicular fiber-reinforced restorations were selected and invited for evaluation. All teeth were restored with the same high-molecular-weight polyethylene fiber (Ribbond, Ribbond Inc) and resin composite cement (Enforce, Dentsply) post-and-core system by a single operator and then prepared and restored with complete cast crowns or direct resin composite. Survival functions of restorations were analyzed with Kaplan-Meier and log-rank tests (alpha = .05) and displayed according to the variable tooth location and material of the definitive restoration. RESULTS: Four posts fractured among the 36 anterior restorations evaluated, and 2 posts fractured among the 73 posterior restorations. The mean overall survival estimate was 90.2 (+/- 3.7) months (95% Cl: 82.8-97.5). There were no differences between survival functions regarding tooth location or type of restorative material as variables (P> .05). CONCLUSIONS: The results suggest that polyethylene fiber-reinforced posts with composite cores may be recommended for clinical use. Restorations evaluated in this study presented high survival rates after the 97-month follow-up period.     

Reconstruction of devital teeth using direct fiber-reinforced composite resins: a case report

Nonrestored devitalized teeth are structurally compromised and represent one of the greatest challenges for the clinician. Restoration of endodontically treated teeth has been associated with the use of posts. Various post materials and designs have been introduced over the years; however, motivated by the desire to conserve the remaining sound tooth structure and thanks to properties of modern adhesive systems, clinicians have re-evaluated the dogma of traditional restorative dentistry and seek alternative methods to build up devitalized teeth. The use of direct Ultra High Molecular Weight Polyethylene (UHMWPE) fiber-reinforced post systems is becoming popular among clinicians because enlargement of the root canal space is not required and the risk of root perforation eliminated. This article presents an experimental clinical technique to reconstruct severely damaged endodontically treated posterior teeth using direct fiber reinforced post systems. Particular attention is paid to the incremental and curing techniques adopted to build up the restoration. The problems that clinicians can encounter in bonding to teeth that have undergone endodontic treatment are also analyzed. Questions that have yet to be answered by scientific research are presented.     

Bonding of composite resin luting cement to fiber-reinforced composite root canal posts

PURPOSE: The aim of this study was to compare bonding of composite resin luting cement to a fiber-reinforced composite (FRC) root canal post with either a cross-linked or a semi-interpenetrating polymer network (IPN) polymer matrix. MATERIALS AND METHODS: Four different types of prefabricated FRC posts with a cross-linked polymer matrix and two types of FRC posts with a semi-IPN polymer matrix which were individually formed were tested. Serrated titanium posts served as the reference. An auto-polymerizing resin luting cement was used for cementing the posts into the holes of composite resin disks. The pull-out force was measured using a universal testing machine after the post/cement/disk system had been stored dry or thermocycled (5 degrees C/55 degrees C, 6000x) in water. The bonding sites of the posts were examined with SEM. RESULTS: The FRC posts with a semi-IPN polymer matrix gave significantly higher pull-out force values than the prefabricated FRC posts with a smooth surface and a cross-linked polymer matrix (p < 0.004). The highest pull-out force was obtained with serrated titanium posts. Both the type of FRC post and thermocycling had a significant effect on the pull-out force (n = 8, ANOVA p < 0.001 and p < 0.007, respectively). SEM photomicrographs confirmed the results. CONCLUSION: This study showed that FRC posts with a semi-IPN polymer matrix bonded better to composite resin luting cement than did prefabricated FRC posts with a cross-linked polymer matrix, although their pull-out force was not as high as that of the mechanically interlocked serrated titanium posts.     

复合树脂高强纤维根管桩在牙体缺损修复中的应用

目的 评价复合树脂高强纤雏根管桩的修复效果。方法 临床选择69例牙体缺损患者。患牙128颗，年龄18～65岁，采用复合树脂高强纤维根管桩作桩棱，金瓷冠修复，6～24个月后对修复效果进行临床评价。分为满意、可接受、不满意。结果 经6～24个月临床观察，本组修复体的美观性、固位、边缘密合性，牙周状况均为满意。结论 复合树脂高强纤维根管桩可以达到满意修复效果。     

4种纤维桩的弯曲强度和显微结构的研究

目的 测试不同纤维桩的弯曲强度,并研究纤维桩弯曲强度与结构特征之间的联系。方法 选择4种品牌的纤维桩进行研究,D.T.Light-Post(BISCO),Pare PostTaper Lux(Coltene/Whaledent),LuxaPost(DMG),国产纤维桩(实德隆)各6根,随机选取5根进行三点弯曲测试,剩余1根及每种品牌中弯曲测试结果最高和最低者用于扫描电镜分析。结果 4种纤维桩的断裂载荷在127.80～157.40N,弯曲强度在820.03～937.95MPa,纤维/基质比值范围为54.56%～78.68%。各项分析结果显示纤维/基质比值与弯曲强度有相关性(P=0.024,r=0.976)。结论 纤维桩弯曲强度与其结构特征相关,纤维/基质比值越高,弯曲强度越大。     

自酸蚀和全酸蚀树脂粘结剂对石英纤维桩固位力影响的比较研究

目的：比较自酸蚀和全酸蚀树脂粘结剂对石英纤维粘结后粘结强度的差异,为临床合理选择粘结剂提供实验依据。方法：选用正常人离体上颌中切牙16颗,经体外完善根管预备并完成根管充填后,于邻面釉牙骨质界水平截断并预备桩道,然后分别包埋在自凝塑料柱内固定。16颗离体牙被随机分成两组,每组各8例,分别用自酸蚀和全酸蚀树脂粘结剂粘结石英纤维桩于牙根桩道内,用力学试验机以1mm／min速度牵拉纤维桩,记录纤维桩与牙根脱离时的最大载荷并进行t检验统计分析。结果：自酸蚀树脂粘结剂石英纤维桩组的粘结强度（246．48N±103．58N）高于全酸蚀粘结剂石英纤维桩组（30．46N±5．41N）,完全随机设计资料的t检验显示P〈0．01,两者差异有显著性。结论：自酸蚀树脂粘结剂石英纤维桩的粘结强度明显优于全酸蚀石英纤维桩粘结剂。     

T-pins in a direct pattern technique for posts and cores.

A practical direct technique for making post and core impressions with a T-pin and self-curing acrylic resin was described. Emphasis was placed on the function of the T-shaped plastic pin in fabricating the pattern. Clinical procedures for each step were described in detail. The unique characteristic of the T-pin of softening and becoming very sticky when exposed to direct contact with acrylic resin monomer allows soft acrylic resin to adhere to it, resulting in an accurate direct impression of the canal.