silicate-cement and Tooth-Fractures

To evaluate the clinical results of ceramic optimized polymer (Targis) posterior inlays.. 345 type I cavities were divided into two groups: 170 in Targis inlays group (42 premolars and 128 molars) and 175 in control group (composite resin inlays, 45 premolars and 130 molars). The clinical effects of Targis inlays and composite resin inlays in posterior teeth were compared in marginal discoloration, marginal adaption, secondary caries, anatomic shape integrity, fractures of tooth and color match 3 years later. The data were analyzed using Chi-square test.. 3 years after treatment, 166 Targis inlays were followed up, 2 had marginal discoloration, 158 had good marginal adaption, 162 had anatomic shape integrity, 1 had secondary caries, 161 had color match, and 5 had fractures of teeth. 169 composite resin inlays were followed up, 27 had marginal discoloration, 134 had good marginal adaption, 150 had anatomic shape integrity, 20 had secondary caries, 164 had color match,5 had fractures of teeth. The marginal discoloration, marginal adaption, secondary caries, anatomic shape integrity of Targis inlays were better than that of composite resin inlays (P < 0.05), but fractures of teeth was not different between inlays in the two group (P > 0.05).. Targis posterior inlays is a good newly developed prosthesis.

Topics: Bicuspid; Ceramics; Color; Composite Resins; Dental Caries; Dental Marginal Adaptation; Dental Porcelain; Glass Ionomer Cements; Humans; Inlays; Molar; Polymers; Silicate Cement; Tooth Fractures

This in vitro study investigated the null hypothesis that metal-free crowns induce fracture loads and mechanical behavior similar to metal ceramic systems and to study the fracture pattern of ceramic crowns under compressive loads using finite element and fractography analyses.. Six groups (n = 8) with crowns from different systems were compared: conventional metal ceramic (Noritake) (CMC); modified metal ceramic (Noritake) (MMC); lithium disilicate-reinforced ceramic (IPS Empress II) (EMP); leucite-reinforced ceramic (Cergogold) (CERG); leucite fluoride-apatite reinforced ceramic (IPS d.Sign) (SIGN); and polymer crowns (Targis) (TARG). Standardized crown preparations were performed on bovine roots containing NiCr metal dowels and resin cores. Crowns were fabricated using the ceramics listed, cemented with dual-cure resin cement, and submitted to compressive loads in a mechanical testing machine at a 0.5-mm/min crosshead speed. Data were submitted to one-way ANOVA and Tukey tests, and fractured specimens were visually inspected under a stereomicroscope (20×) to determine the type of fracture. Maximum principal stress (MPS) distributions were calculated using finite element analysis, and fracture origin and the correlation with the fracture type were determined using fractography.. Mean values of fracture resistance (N) for all groups were: CMC: 1383 ± 298 (a); MMC: 1691 ± 236 (a); EMP: 657 ± 153 (b); CERG: 546 ± 149 (bc); SIGN: 443 ± 126 (c); TARG: 749 ± 113 (b). Statistical results showed significant differences among groups (p < 0.05) represented by different lowercase letters. Metal ceramic crowns presented fracture loads significantly higher than the others. Ceramic specimens presented high incidence of fractures involving either the core or the tooth, and all fractures of polymer crown specimens involved the tooth in a catastrophic way. Based on stress and fractographic analyses it was determined that fracture occurred from the occlusal to the cervical direction.. Within the limitations of this study, the results indicated that the use of ceramic and polymer crowns without a core reinforcement should be carefully evaluated before clinical use due to the high incidence of failure with tooth involvement. This mainly occurred for the polymer crown group, although the fracture load was higher than normal occlusal forces. High tensile stress concentrations were found around and between the occlusal loading points. Fractographic analysis indicated fracture originating from the load point and propagating from the occlusal surface toward the cervical area, which is the opposite direction of that observed in clinical situations.

Topics: Aluminum Oxide; Aluminum Silicates; Animals; Apatites; Bisphenol A-Glycidyl Methacrylate; Cattle; Chromium Alloys; Composite Resins; Crowns; Dental Porcelain; Dental Stress Analysis; Dentin-Bonding Agents; Finite Element Analysis; Glass Ionomer Cements; Lithium Compounds; Materials Testing; Metal Ceramic Alloys; Polyethylene Glycols; Polymethacrylic Acids; Post and Core Technique; Potassium Compounds; Resin Cements; Silicate Cement; Stress, Mechanical; Tooth Fractures; Zinc Phosphate Cement

Fracture resistance of dentin-bonded inlays may be influenced by the restorative material used. The purpose of this study was to evaluate, in vitro, the fracture resistance of teeth restored with four tooth-colored materials: feldspathic ceramic, Duceram LFC, and three laboratory resins, Solidex, Artglass, and Targis. Sixty mandibular molar teeth were placed in resin cylinders, reproducing the periodontal ligaments. Mesial-occlusal-distal (MOD) inlay preparations were made in a standard cavity preparation appliance. Subsequently, the teeth were molded, and the restorations were prepared following the manufacturer's instructions. The inlays were cemented with resin composite cement, Rely X, and stored at 37 degrees C and 100% humidity for 24 hours. The samples were then submitted to an axial compression load at a speed of 0.5 mm/minute. Statistical analysis by one-way ANOVA and Tukey's multiple comparison test revealed that the teeth restored with Duceram LFC (205.44 +/- 39.51 kgf) showed statistically inferior fracture resistance than the three other groups restored with indirect resin composites (Solidex [293.16 +/- 45.86 kgf], Artglass [299.87 +/- 41.08 kgf], and Targis [304.23 +/- 52.52 kgf]).

Topics: Aluminum Silicates; Analysis of Variance; Ceramics; Composite Resins; Dental Cavity Preparation; Dental Porcelain; Dentin-Bonding Agents; Glass Ionomer Cements; Humans; Inlays; Molar; Potassium Compounds; Resin Cements; Silicate Cement; Stress, Mechanical; Tooth Fractures

Topics: Adult; Dental Abutments; Dental Cavity Preparation; Dental Enamel; Dental Prosthesis Design; Glass Ionomer Cements; Humans; Inlays; Male; Metal Ceramic Alloys; Silicate Cement; Tooth Fractures

To evaluate the fracture resistance of teeth restored with direct and indirect restorations of composite resin and restored with indirect ceramic restorations.. Fifty-six maxillary premolar teeth were chosen and divided at random into seven equal groups; Group 1 (control): intact teeth; Group 2: MOD cavity preparations, 1/2 intercuspal distance, with rounded internal angles, convergent walls, unrestored; Group 3: MOD cavity preparations, 1/2 intercuspal distance, divergent walls; Group 4: same preparation as Group 2, restored with direct composite resin (Single Bond/Filtek Z250-3M); Group 5: same as Group 3, restored with indirect composite resin (Artglass/Single Bond/Rely X); Group 6: same as Group 3, restored with indirect composite resin (Targis/Single Bond/Rely X); Group 7: same as Group 3, restored with indirect ceramic restoration (Empress/Single Bond/Rely X). The specimens were subjected to a compressive axial loading in a Universal testing machine at 0.5 mm/minute by means of a steel bar (8 mm in diameter).. The mean fracture strength obtained was: Group 1: 1.91 kN; Group 2: 1.06 kN; Group 3: 0.93 kN; Group 4: 1.45 kN; Group 5: 1.81 kN; Group 6: 1.81 kN; Group 7: 1.77 kN. The restored teeth with direct composite restoration increased the fracture resistance of Group 4 up to 76% of a level comparable with the intact teeth (Group 1). However, statistical analysis indicated no significant (P < 0.05) differences between Group 1 (intact teeth) and restored teeth groups, with direct restorations as well as indirect restorations. Both cavity preparation designs weakened the remaining tooth structure. These results demonstrated that a bonded indirect restoration could satisfactorily be an ideal option for restoring teeth weakened by wide cavity preparation.

Topics: Aluminum Silicates; Analysis of Variance; Bicuspid; Composite Resins; Compressive Strength; Dental Cavity Preparation; Dental Porcelain; Dental Restoration, Permanent; Dental Stress Analysis; Glass Ionomer Cements; Humans; Inlays; Materials Testing; Random Allocation; Silicate Cement; Tooth Fractures

Topics: Aluminum Silicates; Composite Resins; Crowns; Dental Porcelain; Dental Veneers; Glass Ionomer Cements; Humans; Incisor; Male; Maxilla; Middle Aged; Post and Core Technique; Silicate Cement; Tooth Fractures; Tooth, Nonvital

In an in vitro experiment, the failure loads of 59 intact endodontically treated teeth with and without Kerr Endo-Post reinforcement were compared. Fifty-eight teeth fractured below the cementoenamel junction. One tooth fractured through the pulp chamber with a chisel fracture involving both the crown and root. Teeth without posts fractured through the middle or coronal one third of the root. Teeth with posts fractured through the body of the post. No statistically significant reinforcement was demonstrated by cementing a Kerr Endo-Post No. 100 into a sound endodontically treated tooth.

Topics: Crowns; Cuspid; Dental Stress Analysis; Humans; Incisor; Post and Core Technique; Root Canal Therapy; Silicate Cement; Tooth Fractures; Tooth Root; Zinc Phosphate Cement

Topics: Acrylic Resins; Color; Composite Resins; Dental Amalgam; Dental Materials; Dental Porcelain; Dental Restoration, Permanent; Dental Restoration, Temporary; DMF Index; Esthetics, Dental; Humans; Polymers; Silicate Cement; Tooth Fractures

Topics: Crowns; Dental Cavity Preparation; Dental Pins; Esthetics, Dental; Humans; Incisor; Silicate Cement; Tooth Fractures

Topics: Acrylic Resins; Adolescent; Age Factors; Child; Crowns; Dental Clinics; Dental Pulp; Female; Fluorides, Topical; Follow-Up Studies; Gold Alloys; Humans; Inlays; Male; Methods; Pulpotomy; Silicate Cement; Sweden; Time Factors; Tooth Fractures; Tooth Injuries

Topics: Calcium Hydroxide; Child; Crowns; Dental Cavity Preparation; Dental Pulp Calcification; Dental Pulp Necrosis; Dental Pulp Test; Dentin, Secondary; Humans; Male; Orthodontics, Corrective; Pulpotomy; Radiography; Root Canal Obturation; Root Canal Therapy; Silicate Cement; Tooth Discoloration; Tooth Fractures; Tooth Root; Zinc Phosphate Cement