all-bond-2 and Tooth-Fractures

To investigate whether masticatory fatigue affects the fracture resistance and pattern of lower premolars restored with quartz-fiber post-core and full crown, 44 single rooted lower premolars recently extracted from orthodontic patients were divided into two groups of 22 each. The crowns of all teeth were removed and endodontically treated and then restored with quartz-fiber post-core and full crown. Twenty-two teeth in one group were selected randomly and circularly loaded at 45° to the long axis of the teeth of 127.4 N at a 6 Hz frequency, and the other group was not delivered to cyclic loading and considered as control. Subsequently, all teeth in two groups were continually loaded to fail at 45° to the long axis of the teeth at a crosshead speed of 1 mm⋅min(-1). The mean destructive force values were (733.88±254.99) and (869.14±280.26) N for the experimental and the control group, respectively, and no statistically significant differences were found between two groups (P>0.05). Bevel fracture and horizontal fracture in the neck of root were the major fracture mode of the specimens. Under the circumstances of this study, it seems that cyclic loading does not affect the fracture strength and pattern of the quartz-fiber post-core-crown complex.

Topics: Acid Etching, Dental; Adult; Bicuspid; Bite Force; Chromium Alloys; Crowns; Dental Prosthesis Design; Dental Restoration Failure; Dental Stress Analysis; Humans; Materials Testing; Methacrylates; Phosphoric Acids; Post and Core Technique; Quartz; Resin Cements; Stress, Mechanical; Tooth Fractures; Tooth Root; Tooth, Nonvital

In endodontically treated teeth, cuspal coverage plays a fundamental role in reducing the risk of fracture. However, the adhesive techniques with or without fiber post increased the possibilities in restoring root-filled teeth. The aim of this study was to determine the effect of the fiber post and/or post length and/or cuspal coverage on the fracture resistance of endodontically treated maxillary premolars. Seventy intact single-rooted maxillary premolars were selected and divided in seven groups of ten each: "intact teeth" (control), "inlay without fiber post" (G1), "inlay with long fiber post" (G2), "inlay with short fiber post" (G3), "onlay without fiber post" (G4), "onlay with long fiber post" (G5), and "onlay with short fiber post" (G6). Except for intact teeth, all specimens were prepared with a mesio-occluso-distal (MOD) cavity, endodontically treated and restored with or without long or short post, with or without cusp coverage. All specimens were thermal-cycled, exposed to a cyclic loading, and then submitted to the static fracture resistance test. Fracture loads and mode of failure were evaluated. A statistically significant difference in fracture resistance was found between group 1 and the other groups (p < 0.001). χ2 test showed statistically significant differences in the patterns of fractures between the groups (p < 0.001). The highest number of favorable fractures was observed in groups 3 and 4. Similar fracture resistance was detected in maxillary premolars endodontically treated with MOD cavity preparations, restored with either direct resin composite with fiber post or cusp capping. The "short post" direct restoration may be a valid alternative in the restoration of root-filled premolars.

Topics: Acid Etching, Dental; Bicuspid; Composite Resins; Dental Cavity Preparation; Dental Materials; Dental Prosthesis Design; Dental Restoration Failure; Dentin-Bonding Agents; Humans; Inlays; Materials Testing; Maxilla; Methacrylates; Nanocomposites; Phosphoric Acids; Post and Core Technique; Root Canal Preparation; Stress, Mechanical; Temperature; Time Factors; Tooth Fractures; Tooth, Nonvital; Water

Autogenous tooth fragment bonding offers advantages over restorations with composite resins and porcelain, including better esthetics, greater durability, reestablishment of the natural function of the dental element and short execution time. A case is presented of a 14-year-old male patient who suffered an oblique crown fracture of the permanent right maxillary central incisor (11) due to a traumatic fall. The clinical examination revealed pulp exposure with no invasion of the biological space. Due to the extension of the fracture, endodontic treatment and the placement of an intra-root esthetic pin was needed. The tooth was restored using the autogenous fragment bonding method. Excellent esthetic and functional results were observed after two years of follow up.

Topics: Acid Etching, Dental; Adolescent; Composite Resins; Dental Bonding; Dental Materials; Dental Prosthesis Design; Dentin-Bonding Agents; Esthetics, Dental; Follow-Up Studies; Glass; Humans; Incisor; Male; Methacrylates; Post and Core Technique; Root Canal Therapy; Silicon Dioxide; Smiling; Tooth Crown; Tooth Fractures; Zirconium

The introduction of the current enamel-dentin adhesives has simplified the reattachment of fractured dentinal fragments. The objective of this study was to determine the strength needed to detach coronal fragments reattached with the most recent adhesives.. A complete coronal fracture was caused on the incisal one third of 40 noncarious maxillary and mandibular lateral and central incisors. Each fractured coronal fragment was reattached to its tooth with the enamel-dentin adhesive Scotchbond MP, All-Bond 2, Dentastic, or One-Step (10 specimens each).. There was no statistically significant difference between 2 similar fourth-generation adhesives that use orthophosphoric acid as etchant (Dentastic and All-Bond 2) and a fourth-generation adhesive that uses maleic acid as etchant (Scotchbond MP). The values obtained with the fifth-generation adhesive (One-Step) were significantly inferior to those obtained with the other 3 enamel-dentin adhesives.. In the reattachment of fractured tooth fragments, fourth-generation adhesives can guarantee a bonding force stronger than fifth-generation adhesives.

Topics: Dental Bonding; Dentin-Bonding Agents; Humans; Incisor; Methacrylates; Resin Cements; Tooth Crown; Tooth Fractures

This retrospective study evaluated treatment outcome of cast post and core and Composipost systems after 4 yrs of clinical service.. 200 patients were included in the study. They were divided in two groups of 100 endodontically treated teeth restored with a post. Group 1: Composipost systems were luted into root canal following the manufacturer's instructions. Group 2: Cast post and cores were cemented into root canal preparations with a traditional technique. The patients were recalled after 6 months, 1, 2 and 4 yrs and clinical and radiographic examinations were completed. Endodontic and prosthodontic results were recorded.. Group 1: 95% of the teeth restored with Composiposts showed clinical success; 3% of these samples were excluded for noncompliance and 2% showed endodontic failure. Group 2: Clinical success was found with 84% of teeth restored with cast post and core. 2% of these samples were excluded for noncompliance, 9% showed root fracture, 2% dislodgment of crown and 3% endodontic failure. Statistical evaluation showed significant differences between Groups 1 and 2 (P < 0.001). The results of this retrospective study indicated that the Composipost system was superior to the conventional cast post and core system after 4 yrs of clinical service.

Topics: Boron Compounds; Carbon; Carbon Fiber; Cementation; Composite Resins; Confidence Intervals; Crowns; Dental Abutments; Dental Materials; Dental Prosthesis Design; Dental Restoration Failure; Dentin-Bonding Agents; Epoxy Resins; Follow-Up Studies; Gold Alloys; Gutta-Percha; Humans; Life Tables; Metal Ceramic Alloys; Methacrylates; Methylmethacrylates; Post and Core Technique; Retrospective Studies; Root Canal Filling Materials; Root Canal Therapy; Statistics as Topic; Tooth Fractures; Tooth Root; Treatment Outcome; Zinc Phosphate Cement

To compare the fracture strength of intact teeth with that of fractured crowns bonded with adhesive and a resin material on either wet or dry dentin, or dried dentin rewetted with a rewetting agent for various periods of time.. Sheep central incisors were divided into seven groups, each of 10 teeth. Group 1: Intact teeth tested for fracture strength in an Instron testing machine and used as controls. Groups 2-7 were sectioned in a vice equipped with sharp blades, 2.5 mm away from and parallel to the incisal edge. The two fracture surfaces were etched with 37% phosphoric acid for 15 s and rinsed with water for 5-6 s. Group 2: The surfaces were air-dried for 2 s. Group 3: As for Group 2 but the surfaces were rewetted with Aqua-Prep for 2 s and immediately air-blasted to remove excess. Group 4: As for Group 3, but the rewetting agent was applied for 10 s before air-blasting. Group 5: As for Group 4, but the rewetting agent was applied for 20 s. Group 6: As for Group 4, but the rewetting agent was applied for 30 s. Group 7: As for Group 2, but the surfaces were left moist after etching and rinsing by gently shaking the specimens twice. The fracture surfaces of Groups 2-7 were rebonded with All-Bond 2 adhesive system and Aeliteflo composite. After 48 hrs the restored teeth were debonded in the Instron testing machine. Fracture strengths were calculated and compared with the fracture strength of intact teeth (control group).. Newman-Keuls' multiple range test revealed that there was a statistically significant difference between the control mean and the means of Groups 2 and 3. All other means were not significantly different. Drying of the dentin surface decreased the bonding strength, and rewetting of the dried dentin for 2 s was not sufficient to rewet the collapsed collagen fibers, as indicated by a decrease of fracture strength.

Topics: Acid Etching, Dental; Animals; Barium Compounds; Bisphenol A-Glycidyl Methacrylate; Composite Resins; Dental Bonding; Dental Stress Analysis; Dentin-Bonding Agents; Incisor; Materials Testing; Methacrylates; Resin Cements; Sheep; Silicon Dioxide; Statistics, Nonparametric; Tooth Fractures; Wetting Agents

Endodontically treated teeth present a myriad of problems because of coronal destruction from caries, previous restorations, and coronal access. Previously, a post was considered necessary to strengthen a tooth and to resist intraoral forces. However, recent research has indicated that not all endodontically treated teeth require a post, core, and crown. Each clinical situation must be evaluated and the need for a post and/or the appropriate post determined. The recent introduction of a carbon-fiber post may reduce some of the problems inherent with metal posts. Proper placement, advantages, and disadvantages are discussed.

Topics: Acid Etching, Dental; Carbon; Carbon Fiber; Dental Alloys; Dental Cements; Dental Materials; Dental Prosthesis Design; Dental Prosthesis Retention; Dental Restoration Failure; Dentin-Bonding Agents; Elasticity; Epoxy Resins; Humans; Methacrylates; Post and Core Technique; Root Canal Therapy; Stress, Mechanical; Surface Properties; Tensile Strength; Tooth Fractures