feldspar and Tooth-Fractures

This article is part of a randomized clinical trial on different treatments in the shortened dental arch (SDA). It focused on the abutment tooth prognosis with cantilevered fixed dental prostheses (CFDPs).. Sixty-two patients with a bilaterally SDA up to the first or second premolar in the mandible or maxilla were evaluated. In 57 of 124 quadrants, second premolars were replaced by a CFDP (cantilever group). In the remaining 67 quadrants, a natural second premolar was present and thus no need for a CFDP was given (non-cantilever group). Patients were recalled annually up to 5 years.. The mean observation period was 56.3 months (min. 3.0, max. 76.2, SD 16.1). Kaplan-Meier survival rates concerning tooth loss and tooth fracture were 93.9%/94.0% in the cantilever group and 91.9%/92.8% in the non-cantilever group. Differences between both groups were not significant. The survival rate concerning loss of retention of CFDP retainers was 92.1% in the cantilever group.. After 5 years of clinical service, CFDPs for the replacement of the second premolar showed no negative impact on the abutment tooth prognosis.. Cantilevered fixed dental prostheses present a viable treatment option in the shortened dental arch without compromising the medium-term abutment tooth prognosis.

Topics: Adult; Aluminum Silicates; Bicuspid; Cuspid; Dental Abutments; Dental Arch; Dental Porcelain; Denture Design; Denture Retention; Denture, Partial, Fixed; Follow-Up Studies; Gold Alloys; Humans; Jaw, Edentulous, Partially; Mandible; Maxilla; Metal Ceramic Alloys; Potassium Compounds; Survival Rate; Tooth Fractures; Tooth Loss; Treatment Outcome

To assess the fracture strength of dentin-bonded crowns placed on cores of amalgam, resin composite and viscous glass-ionomer.. 40 sound maxillary premolar teeth were selected. These were mounted in acrylic resin in stainless steel molds. The palatal cusp of each tooth was removed in a standardized manner to simulate a core build-up preparation. Teeth were randomly divided into four groups, and each group was allocated a core material. For Group A, the core was pin-retained amalgam, for Group B the core was bonded amalgam, for Group C the core material was resin composite and for Group D the core material was high-viscosity glass-ionomer material. Cores were then constructed to the original tooth dimensions. A standardized crown preparation was made, impressions taken and an all-ceramic crown constructed in feldspathic porcelain. The crowns were luted in position using a dentin-bonding agent/dual cure resin-composite cement and the completed specimens subjected to compressive loading in a Universal Testing machine at 1 mm/minute.. The mean forces to produce fracture of the crowns were 1.58 kN (+/- 0.41), 1.35 kN (+/- 0.44), 1.25 kN (+/- 0.24), and 1.12 kN (+/- 0.25) respectively for groups A, B, C and D. Statistical analysis by ANOVA indicated that the pinned amalgam group performed significantly better than the glass-ionomer group (P > 0.05).

Topics: Aluminum Silicates; Analysis of Variance; Ceramics; Composite Resins; Compressive Strength; Crowns; Dental Amalgam; Dental Bonding; Dental Pins; Dental Porcelain; Dental Prosthesis Design; Dentin-Bonding Agents; Glass Ionomer Cements; Humans; Materials Testing; Post and Core Technique; Potassium Compounds; Resin Cements; Stress, Mechanical; Tooth Fractures; Tooth Preparation

The aim of this study was to evaluate the mode of fracture and resistance of partial ceramic restorations of posterior teeth.. Thirty healthy upper premolars were selected and divided into three groups (n = 10): Group 1- control, healthy unrestored teeth, group 2-teeth restored with ceramic fragments; and group 3-teeth restored with ceramic overlays. The restorations were manufactured with feldspathic ceramic and cemented with RelyX ARC resin cement. After being stored in distilled water for 7 days, the teeth were subjected to axial compression mechanical testing with a universal testing machine. Force was applied to the long axis of the tooth at a speed of 0.5 mm/min until fracture. The data were analyzed with one-way ANOVA and Tukey's test (5%). The mode of fracture was scored according to the degree of involvement of the tooth structure and the type of restoration.. A significant difference (p < 0.05) was showed between groups 2 (1155 N) and 3 (846.6 N), but there was no significant difference between group 1 and the other groups (1046 N), More extensive fractures were prevalent in the healthy teeth group (Group 1), which had no occlusal coverage; less severe fractures were found in groups 2 and 3.. We conclude that teeth restored with ceramic fragments may offer greater resistance to fractures compared to teeth that have overlay restorations.

Topics: Acid Etching, Dental; Aluminum Silicates; Bicuspid; Bisphenol A-Glycidyl Methacrylate; Ceramics; Compressive Strength; Dental Porcelain; Dental Prosthesis Design; Dental Restoration Failure; Dental Stress Analysis; Humans; Hydrofluoric Acid; Inlays; Materials Testing; Polyethylene Glycols; Polymethacrylic Acids; Potassium Compounds; Resin Cements; Stress, Mechanical; Surface Properties; Time Factors; Tooth Fractures; Water

Topics: Adult; Aged, 80 and over; Aluminum Silicates; Ceramics; Composite Resins; Computer-Aided Design; Crowns; Dental Implants, Single-Tooth; Dental Impression Technique; Dental Marginal Adaptation; Dental Materials; Dental Porcelain; Dental Prosthesis Design; Dentistry, Operative; Female; Humans; Image Processing, Computer-Assisted; Imaging, Three-Dimensional; Optical Devices; Patient Care Planning; Point-of-Care Systems; Post and Core Technique; Potassium Compounds; Software; Tooth Fractures; User-Computer Interface

This report describes immediate implant placement after the extraction of a vertically fractured tooth. During the healing phase, a resin-bonded prosthesis was inserted as a provisional restoration. After the creation of the optimal emergence profile and papillae with the provisional restoration, the definitive metal ceramic crown was fabricated.

Topics: Adult; Aluminum Silicates; Chromium Alloys; Crowns; Dental Implantation, Endosseous; Dental Implants, Single-Tooth; Dental Porcelain; Denture, Partial, Fixed, Resin-Bonded; Denture, Partial, Temporary; Follow-Up Studies; Gingiva; Humans; Incisor; Magnesium Oxide; Male; Metal Ceramic Alloys; Osseointegration; Polycarboxylate Cement; Potassium Compounds; Resin Cements; Tooth Extraction; Tooth Fractures; Tooth Root; Tooth Socket; Zinc Oxide

Topics: Aluminum Silicates; Bicuspid; Ceramics; Communication; Computer-Aided Design; Crowns; Dental Abutments; Dental Materials; Dental Porcelain; Dental Prosthesis Design; Dental Technicians; Dental Veneers; Dentists; Humans; Interprofessional Relations; Laboratories, Dental; Patient Care Planning; Potassium Compounds; Technology, Dental; Tooth Fractures; Zirconium

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

Novel-design bonded porcelain restorations, the so-called Type IIIA BPRs, represent a reliable and effective procedure when restoring large parts of the coronal volume and length in the anterior dentition. While traditional treatment approaches involve the removal of large amounts of sound tooth substance (with adverse effects on the pulp, gingivae and crown biomechanics, as well as serious financial consequences), the use of adhesive technology instead can provide maximum preservation of tissues and limited costs. Considerable advantages, such as the economical and noninvasive treatment of crown-fractured teeth, are inherent to Type IIIA bonded porcelain restorations, reducing the need for preprosthetic interventions (e.g., root canal therapy and crown-lengthening) and the use of intraradicular posts. This article, illustrated with cases with up to eight and 10 years' follow-up, sets the scientific foundations of this concept, as well as important considerations about function, strength, tooth preparation, laboratory technique, and bonding optimization.

Topics: Adolescent; Adult; Aluminum Silicates; Child; Dental Bonding; Dental Porcelain; Dental Restoration, Permanent; Dental Stress Analysis; Dental Veneers; Humans; Incisor; Potassium Compounds; Tooth Crown; Tooth Fractures; Tooth Preparation

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

The present study evaluated the clinical performance of bonded porcelain veneers (PV) restoring substantial coronal volume and length in the anterior dentition. Forty-eight PVs were placed in 16 patients, with systematic coverage and reconstitution of the incisal edge, including well-defined anterior guidance. A standardized protocol comprising diagnostic steps that integrate additive waxups and acrylic mockups was used. PVs were fabricated using feldspathic and low-fusing porcelains in a refractory die technique. Incisal overlaps featured freestanding porcelain spans ranging from 1.5 to 5.5 mm. After a mean clinical service of 4.5 years, 13 clinical parameters for each tooth and 4 parameters that applied to persons were recorded. Permutation tests evaluated the effects of margin location, incisal edge span of porcelain, overbite, opposing contact location, and restoration age on ceramic failure and clinical marginal adaptation and seal. At recall, 100% of the veneers were satisfactory with minor interventions. The effect of slight marginal defects and porcelain cracking was negligible. Biologic, periodontal, and esthetic parameters showed excellent results, which were supported by 100% patient-reported satisfaction. All patients felt comfortable with the newly defined anterior guidance. Aging was negligible, and there were no significant effects of margin location (P > 0.08), incisal edge span of the ceramic, or overbite (P > 0.22) on ceramic failure and marginal performance. Minor alterations of the palatal margin, however, tended to be more frequent compared to facial locations, and were found especially when the opposing tooth contact in centric occlusion was located on the palatal margin (P = 0.028). Bonded ceramic restorations represent a reliable, effective procedure to restore extensive coronal volume and length in the anterior dentition.

Topics: Acrylic Resins; Adolescent; Adult; Aluminum Silicates; Bicuspid; Cuspid; Dental Bonding; Dental Casting Technique; Dental Occlusion, Centric; Dental Porcelain; Dental Prosthesis Design; Dental Restoration Failure; Dental Veneers; Esthetics, Dental; Female; Follow-Up Studies; Humans; Incisor; Male; Middle Aged; Patient Satisfaction; Potassium Compounds; Surface Properties; Tooth Fractures