Microtensile bond strength of root canal dentin treated with adhesive and fiber-reinforced post systems.

Nowadays, demand for esthetic restorations has risen considerably; thus, nonmetal esthetic posts made of either high-strength ceramics or reinforced resins, such as fiber-reinforced resin posts, have become more and more popular. Important characteristics of fiber-reinforced posts involve a modulus of elasticity similar to dentin and their ability to be cemented by an adhesive technique. A total of 36 maxillary incisors were divided into four groups. In this study, four adhesively luted fiber-reinforced (glass fiber, quartz glass fiber, zirconia glass fiber and woven polyethylene fiber ribbon) post systems were used. Post spaces were prepared by employing drills according to the protocol established for each group, and each post was adhesively luted with one of three adhesive systems. Three segments per root apical to the cementoenamel junction (CEJ) were obtained by sectioning the root under distilled water with a carbon spare saw. The samples (total of 108 sections) were 2.0±0.1 mm in thickness and they were stored individually in black film canisters with sterile distilled water. In order to determine the bond strength, the bonding area of each specimen was measured, and specimens were attached to a device to test microtensile strength at a speed of 1 mm/min. The analyses revealed no statistically significant differences between the adhesive systems and fiber-reinforced posts. (P> 0.05). However, the coronal portion of the root dentin had the highest bond strength. Adhesive systems used along with fiber-reinforced resin posts demonstrated reliable bonding.

Microtensile bond strength of root canal dentin treated with adhesive and fiber-reinforced post systems

Abstract Nowadays, demand for esthetic restorations has risen considerably; thus, nonmetal esthetic posts made of either high-strength ceramics or reinforced resins, such as fiber-reinforced resin posts, have become more and more popular. Important characteristics of fiber-reinforced posts involve a modulus of elasticity similar to dentin and their ability to be cemented by an adhesive technique. A total of 36 maxillary incisors were divided into four groups. In this study, four adhesively luted fiber-reinforced (glass fiber, quartz glass fiber, zirconia glass fiber and woven polyethylene fiber ribbon) post systems were used. Post spaces were prepared by employing drills according to the protocol established for each group, and each post was adhesively luted with one of three adhesive systems. Three segments per root apical to the cementoenamel junction (CEJ) were obtained by sectioning the root under distilled water with a carbon spare saw. The samples (total of 108 sections) were 2.0±0.1 mm in thickness and they were stored individually in black film canisters with sterile distilled water. In order to determine the bond strength, the bonding area of each specimen was measured, and specimens were attached to a device to test microtensile strength at a speed of 1 mm/min. The analyses revealed no statistically significant differences between the adhesive systems and fiber-reinforced posts. (P> 0.05). However, the coronal portion of the root dentin had the highest bond strength. Adhesive systems used along with fiber-reinforced resin posts demonstrated reliable bonding.

Comparison of Load-Bearing Capacities of 3-Unit Fiber-Reinforced Composite Adhesive Bridges with Different Framework Designs.

BACKGROUND The aim of this study was to investigate and compare the load-bearing capacities of three-unit direct resin-bonded fiber-reinforced composite fixed dental prosthesis with different framework designs. MATERIAL AND METHODS Sixty mandibular premolar and molar teeth without caries were collected and direct glass fiber-resin fixed FDPs were divided into 6 groups (n=10). Each group was restored via direct technique with different designs. In Group 1, the inlay-retained bridges formed 2 unidirectional FRC frameworks and pontic-reinforced transversal FRC. In Group 2, the inlay-retained bridges were supported by unidirectional lingual and occlusal FRC frameworks. Group 3, had buccal and lingual unidirectional FRC frameworks without the inlay cavities. Group 4 had reinforced inlay cavities and buccal-lingual FRC with unidirectional FRC frameworks. Group 5, had a circular form of fiber reinforcement around cusps in addition to buccal-lingual FRC frameworks. Group 6 had a circular form of fiber reinforcement around cusps with 2 bidirectional FRC frameworks into inlay cavities. All groups were loaded until final fracture using a universal testing machine at a crosshead speed of 1 mm/min. RESULTS Mean values of the groups were determined with ANOVA and Tukey HSD. When all data were evaluated, Group 6 had the highest load-bearing capacities and revealed significant differences from Group 3 and Group 4. Group 6 had the highest strain (p>0.05). When the fracture patterns were investigated, Group 6 had the durability to sustain fracture propagation within the restoration. CONCLUSIONS The efficiency of fiber reinforcement of the restorations alters not only the amount of fiber, but also the design of the restoration with fibers.

Effect of Different Esthetic Post-Core Materials on Color of Direct-Composite Restorations: A Preliminary Clinical Study.

BACKGROUND The purpose of this study was to determine the influence of 2 different esthetic post materials on the final color of direct-composite restorations by using a digital technique under in vivo conditions. MATERIAL AND METHODS We included 22 pulpless incisor teeth treated with conventionally cemented zirconia (n=11) and polyethylene fiber (n=11) posts in the study. Teeth were restored with a hybrid resin. The color of direct-composite restorations and contralateral control teeth was measured using a digital technique. The Commission Internationale de L'Eclairage, or CIE, L*a*b* and RGB color systems were investigated. Descriptive statistical analysis was performed for the CIE L*a*b* values. Color differences (ΔE) for the average L*, a*, and b* color parameters between every pair of groups were calculated (P>.05). RESULTS Significant differences were not found in the color difference luminosity (lum), R, G, B, and L* a* b* values between the zircon-rich glass fiber post (Z) and contralateral control teeth (Cz) (P>.05) and between the polyethylene fiber post (P) and contralateral control teeth (Cp) (P>.05). However, there was a statistically significant difference between the color a* values of the polyethylene fiber post (P) and contralateral control teeth (Cp) (p<0.05). Color differences (ΔE) between the zircon-rich glass fiber post (Z) and contralateral control teeth, and the polyethylene fiber post (P) and contralateral teeth were not statistically significant (P>.05). CONCLUSIONS Definitive restorations were equally affected by the 2 materials. Both materials can be used reliably in clinical practice. However, further research that focuses on the effect of intraoral conditions is needed.

Comparison of the clinical efficacy of two different types of post systems which were restored with composite restorations.

AIM: To compare the efficacy of resin composite restorations, retained with either polyethylene or zirconia-rich glass fiber posts. METHODS: Sixty-two single rooted maxillary and mandibular central incisor teeth in forty-four patients (15 males and 29 females; age range 15-32 years) were restored either with an ultrahigh molecular weight polyethylene (UHMWP) fiber post (Bondable Reinforcement Ribbon, DENSE, Ribbond, Seattle, WA, United States) or a zircon-rich glass fiber post (Snowpost, Lot H 040; Carbotech, Ganges, France). Then, direct resin composite restoration (Clearfil AP-X, Kuraray) was performed for both post systems in tooth color suitable. Patients were recalled for routine inspections at 6 mo, 1, 2 and 3 years. RESULTS: The restorations were assessed during each recall evaluation according to predetermined clinical and radiographic criteria (periapical lesion; marginal leakage and integrity; color stability; surface stain and loss of retention of the post or the composite build-up material). The follow-up data showed no significant difference in these criteria between polyethylene fibre posts and zirconia-rich glass fibre posts. CONCLUSION: The efficacy of resin composite restorations, retained with either polyethylene or zirconia-rich glass fiber posts were similar, suggesting that both types of fiber post can be used successfully to help retain resin composite restorations.

Load bearing capacity of fiber-reinforced and unreinforced composite resin CAD/CAM-fabricated fixed dental prostheses.

STATEMENT OF PROBLEM: It is unclear if fiber-reinforced fixed dental prostheses can be fabricated with physical properties that make them suitable for definitive prostheses. PURPOSE: The purpose of this study was to compare the load bearing capacity of fiber-reinforced and unreinforced computer-aided design/computer-aided manufacturing (CAD/CAM) fabricated fixed dental prostheses. MATERIAL AND METHODS: Fixed dental prostheses were fabricated with CAD/CAM from 3 experimental fiber-reinforced composite resin blocks, 1 experimental composite resin block, and 1 commercially available composite resin block. The experimental fiber-reinforced composite resin was prepared by mixing dimethacrylate resin with filler particles of BaO silicate and E-glass fiber. Different ratios of resin, filler, and fiber were used to fabricate specimens measuring 15.5 × 19 × 39 mm, which were allocated to 5 different groups (n=8) and statically loaded until final fracture. Statistical analyses were calculated according to final fracture values. A 1-way ANOVA and the Tukey post hoc multiple comparison test were used (α=.05). RESULTS: All groups showed significantly different load-bearing capacities (P<.001). Experimental randomly oriented fiber-reinforced composite resin blocks revealed the highest load-bearing capacity (2163 ±246 N), whereas commercial composite resin blocks showed the lowest (1290 ±172 N). CONCLUSIONS: Fixed partial dental prostheses consisting of experimental fiber-reinforced composite resin blocks showed higher load-bearing capacities than did unreinforced composite resin blocks.

Load-bearing capacity of fiber reinforced fixed composite bridges.

OBJECTIVE: The aim of this study was to evaluate the reinforcing effect of differently oriented fibers on the load-bearing capacity of three-unit fixed dental prostheses (FDPs). MATERIALS AND METHODS: Forty-eight composite FDPs were fabricated. Specimens were divided into eight groups (n = 6/group; codes 1-8). Groups 1 and 5 were plain restorative composites (Grandio and Z100) without fiber reinforcement, groups 2 and 6 were reinforced with a continuous unidirectional fiber substructure, groups 3 and 7 were reinforced with a continuous bidirectional fiber and groups 4 and 8 were reinforced with a continuous bidirectional fiber substructure and continuous unidirectional fiber. FDPs were polymerized incrementally with a handheld light curing unit for 40 s and statically loaded until final fracture. RESULTS: Kruskal-Wallis analysis revealed that all groups had significantly different load-bearing capacities. Group 4 showed the highest mean load-bearing capacity and Group 7 the lowest. CONCLUSION: The results of this study suggest that continuous unidirectional fiber increased the mechanical properties of composite FDPs and bidirectional reinforcement slowed crack propagation on abutments.

Microleakage of endodontically treated teeth restored with 3 different adhesive systems and 4 different fiber-reinforced posts.

STATEMENT OF PROBLEM: Despite recent advances in adhesive dentistry, fiber-reinforced post/resin cement/dentin adhesive combinations are not able to prevent microleakage. While studies have examined microleakage in endodontically treated teeth restored with posts and cores, microleakage among post and adhesive systems remains a concern. PURPOSE: This study compared the sealing properties of 4 adhesively luted post systems: glass fiber, quartz-glass fiber, zirconia-glass fiber and polyethylene fiber posts. MATERIAL AND METHODS: Forty-eight permanent maxillary central incisors were divided into 4 groups (n=12). Post space was prepared and each post was adhesively luted with 1 of 3 systems: a 1-stage self-etch, a 2-stage total-etch, and a 3-stage total-etch adhesive. The specimens were separately immersed in freshly prepared 2% methylene blue solution for 1 week. The cleaned specimens were then embedded in autopolymerizing acrylic resin. The teeth were horizontally sectioned into apical, middle, and coronal portions. An occlusal view of each section was digitally photographed with a stereomicroscope. The methylene blue-infiltrated surface for each specimen was measured and data were collected with software. Dye penetration was estimated as the ratio of the methylene blue-infiltrated surface to the total dentin surface. Nonparametric data were analyzed with the Kruskal-Wallis test (α=.05). The Mann-Whitney U-test was used to compute multiple pairwise comparisons that identified differences among groups. Dentin-luting agent and post interfaces were evaluated with a scanning electron microscope. RESULTS: Significant differences in adhesive and post systems were observed in all sectioned regions (P<.05). There were significant differences between the apical and coronal sections of each post type, and between the following pairs: middle versus coronal sections of zirconia-glass fiber and glass fiber posts and apical versus middle sections of quartz-glass fiber and polyethylene fiber posts (P<.05). No significant differences were found among post types. The variables of middle section and 3-stage adhesive produced significant differences in microleakage between the following post pairs: zirconia-glass fiber versus quartz-glass fiber, zirconia-glass fiber versus polyethylene fiber, and quartz-glass fiber versus polyethylene fiber (P<.05). CONCLUSIONS: The 3-stage adhesive and zirconia-glass fiber posts demonstrated the least microleakage.

Load-bearing capacity of handmade and computer-aided design--computer-aided manufacturing-fabricated three-unit fixed dental prostheses of particulate filler composite.

OBJECTIVE: To compare handmade and computer-aided design-computer-aided manufacturing (CAD-CAM)-fabricated fixed dental prostheses (FDPs) composed of a particulate filler composite. MATERIAL AND METHODS: Handmade FDPs were made of restorative composite (Z 100) and CAD-CAM-fabricated FDPs were made of commercial CAD-CAM blocks (VITA Temp) and two experimental CAD-CAM blocks of particulate filler composite. Experimental CAD composite A was prepared by mixing 31.2 wt.% of dimethacrylate resin with 68.7 wt.% of filler particles of barium oxide silicate (BaSiO(2)). Experimental CAD composite B was prepared by mixing 25.6 wt.% of dimethacrylate resin with 74.3 wt.% of filler particles of BaSiO(2). Six groups were fabricated (n = 6 in each); FDPs were statically loaded until final fracture. RESULTS: Experimental CAD composites A and B revealed the highest load-bearing capacity of the FDPs, while Z 100 showed the lowest. CONCLUSION: FDPs made of experimental CAD composite blocks showed higher load-bearing capacities than handmade commercial composites and commercial blocks.

Influence of different power outputs of erbium, chromium:yttrium-scandium-gallium-garnet laser and acid etching on shear bond strengths of a dual-cure resin cement to enamel.

The purpose of the study was to determine if the irradiation of enamel with laser of different output powers might be viable alternatives to acid etching for the bonding of resin luting agents. Seventy-seven maxillary central incisors, extracted for periodontal reasons, were used. The enamel was etched with an erbium, chromium:yttrium-scandium-gallium-garnet (Er,Cr:YSGG) laser operated at one of six power outputs (0.5 W, 0.75 W, 1 W, 1.5 W, 1.75 W and 2 W) or with 38% phosphoric acid. Seventy teeth were used for the bond strength experiments, and the remaining seven (one specimen for each group) were used for scanning electron microscopy (SEM) to determine the topography and morphology of the treated enamel surface. The acid-etched group yielded the highest mean of shear bond strength (13.5 ± 2.8 MPa). The means of the shear bond strength for the teeth irradiated at 0.5 W, 0.75 W, 1 W, 1.5 W , 1.75 W and 2 W laser were 3.28 ± 2.4 MPa, 5.44 ± 3.4 MPa, 8.8 ± 4.5 MPa, 10.2 ± 4.0 MPa, 11.4 ± 4.8 MPa and 11.9 ± 4.3 MPa, respectively. Laser irradiation at 1.5 W, 1.75 W and 2 W produced a type III acid-etched pattern similar to that produced by acid etching. No significant enamel surface etching was obtained by 0.5 W or 0.75 W laser irradiation. Irradiation at 0.5 W and 0.75 W produced a type V acid-etched pattern. We concluded that the mean shear bond strength and enamel surface etching obtained with Er,Cr:YSGG laser (operated at 1.5 W and 1.75 W for 15 s) is comparable to that obtained with acid etching.

Endodontic and prosthetic treatment of teeth with periapical lesions in a 16-year-old-girl.

This paper reports the nonsurgical endodontic therapy using calcium hydroxide intracanal dressing and prosthetic treatment of 9 teeth with periapical lesions in a 16-year-old female patient. The periodontal treatment plan included oral hygiene instructions, mechanical debridement and gingivectomy in the maxillary incisors to improve gingival contouring. Root canal treatment was indicated for teeth 11-13, 21, 22, 42-45. After successive changes of a calcium hydroxide intracanal dressing during 6 weeks, the size of the periapical radiolucencies decreased and lesion remission occurred after root canal obturation. The endodontically treated teeth received a bondable polyethylene reinforcement fiber (Ribbond) in the prepared canal space and crown buildup was done with composite resin. Prosthetic rehabilitation was planned with single-unit metal-ceramic crowns and fixed partial dentures. Clinical and radiographic evaluation after 6 months showed successful results. The outcomes of this case showed that chronic periapical lesions can respond favorably to nonsurgical endodontic treatment in adolescent patients and that, with proper indication, polyethylene fibers can provide an effective conservative and esthetic option for reinforcing endodontically treated teeth undergoing prosthetic rehabilitation.

Endodontic and prosthetic treatment of teeth with periapical lesions in a 16-year-old-girl

This paper reports the nonsurgical endodontic therapy using calcium hydroxide intracanal dressing and prosthetic treatment of 9 teeth with periapical lesions in a 16-year-old female patient. The periodontal treatment plan included oral hygiene instructions, mechanical debridement and gingivectomy in the maxillary incisors to improve gingival contouring. Root canal treatment was indicated for teeth 11-13, 21, 22, 42-45. After successive changes of a calcium hydroxide intracanal dressing during 6 weeks, the size of the periapical radiolucencies decreased and lesion remission occurred after root canal obturation. The endodontically treated teeth received a bondable polyethylene reinforcement fiber (Ribbond) in the prepared canal space and crown buildup was done with composite resin. Prosthetic rehabilitation was planned with single-unit metal-ceramic crowns and fixed partial dentures. Clinical and radiographic evaluation after 6 months showed successful results. The outcomes of this case showed that chronic periapical lesions can respond favorably to nonsurgical endodontic treatment in adolescent patients and that, with proper indication, polyethylene fibers can provide an effective conservative and esthetic option for reinforcing endodontically treated teeth undergoing prosthetic rehabilitation.

Prosthodontic Rehabilitation Alternative of Patients with Cleft Lip and Palate (CLP): Two Cases Report.

Although patients with cleft lip and palate (CLP) are not seen regularly in general dental practice, this is a frequent congenital anomaly; approximately one in every 800 live births results in a CLP. The cause of CLP is unknown, but possible causes are malnutrition and irradiation during pregnancy, psychological stress, teratogenic agents, infectious agents (viruses), and inheritance. Most clefts are likely caused by multiple genetic and nongenetic factors. Prosthetic reconstruction of the anterior maxilla is important for these patients. This paper describes the prosthetic rehabilitation of two patients with CLP, 19-year-old and 21-year-old women, both with surgically treated CLP. In both, an examination revealed a residual palatal defect of 2 x 3 mm and missing maxillary lateral incisors. The 19-year-old was treated with a fiber-reinforced composite resin-bonded fixed partial denture. The 21-year-old was treated with a removable partial denture with an extracoronal attachment system. The prosthetic rehabilitation of the two patients with CLP was evaluated clinically. In both, well-planned prosthetic, periodontal, and surgical therapy resulted in satisfactory function and esthetics, alleviating their deformities. With education and appropriate recall, the patients should be able to maintain their oral health.

Restoring function and esthetics in 2 patients with amelogenesis imperfecta: case report.

This case report describes the prosthodontic treatment for a 28-year-old man and a 16-year-old boy diagnosed with amelogenesis imperfecta. The aim of treatment was to reduce dental sensitivity and to restore esthetics and masticatory function. Because of the socioeconomic status of the patients, direct resin composite laminate veneers were used to improve the esthetics of their maxillary and mandibular anterior teeth. Clinical examination 12 months after treatment revealed no evidence of disorders associated with the restored teeth or their supporting structures. Definitive treatment outcomes in terms of function and esthetics satisfied the expectations of both the patient and the interdisciplinary team.

Multiple root fracture: a case report.

An 11-year-old boy was diagnosed with a horizontal root fracture in the maxillary right lateral incisor and a crown fracture in the maxillary right central incisor. This patient was treated endodontically and conservatively. At a follow-up examination 36 months after treatment, the teeth were functionally and esthetically normal. Radiographically, no pathosis was evident in periapical or fracture areas.

Direct restorative treatment of peg-shaped maxillary lateral incisors with resin composite: a clinical report.

This clinical report describes a treatment approach for esthetically restoring peg-shaped lateral incisors. Four patients with peg-shaped lateral incisors were restored with direct resin composite laminate veneers.

Use of an alternative pontic foundation technique for a fiber-reinforced composite fixed partial denture: a clinical report.

This article describes the treatment of a patient for whom a fiber-composite laminate dowel and core and polyethylene fiber were used as a conservative alternative to provide a dowel-and-core and fixed partial denture foundation. The treatment plan included removing the existing restoration on the maxillary right first molar, placing a fiber-reinforced resin dowel and core for retention and reinforcement of the maxillary first premolar, and fabricating a definitive restoration using polyethylene fiber to reinforce the fixed partial denture.

Polyethylene fiber-reinforced composite inlay fixed partial dentures: two-year preliminary results.

PURPOSE: Polyethylene fiber-reinforced composite inlay fixed partial dentures (FPDs) have been under development for some time. There is a lack of data on the clinical performance of such prostheses. This prospective clinical study evaluated the clinical performance of polyethylene fiber-reinforced composite FPDs over two years. MATERIALS AND METHODS: Twenty-eight polyethylene fiber-reinforced composite inlay FPDs were fabricated for 19 patients. The treatment plan included removal of the existing restorations, placement of an ultrahigh molecular weight polyethylene (UHMWP) fiber ribbon, and final restoration with a light-curing hybrid resin. The 28 polyethylene fiber-reinforced composite inlay FPDs were examined clinically after 2 years. RESULTS: All 28 FPDs were intact at the 2-year examination. There were no signs of fracture, debonding, or discoloration. CONCLUSION: Based on the results of this descriptive study, the polyethylene fiber-reinforced composite inlay FPDs were considered clinically successful at the 2-year examination.