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Metal Framework (metal + framework)
Selected AbstractsCrown-Ether-Like PbII -Metal Framework with Dual- and Bimodal Emissive Properties Based on Its Photochromic Precursor by LeachingCHEMISTRY - A EUROPEAN JOURNAL, Issue 41 2009You-Yun Jiang Kingdom for a lead crown: A crown-ether-like, open PbII framework is generated from its phtotochromic precursor by a leaching approach. The dual and bimodal emissions are successfully realized by intercalation of the different Ln3+ hydrates into the hollow PbII framework based on a guest-driven approach (see graphic). [source] Long-term outcomes for cross-arch stabilizing bridges in periodontal maintenance patients , a retrospective studyJOURNAL OF CLINICAL PERIODONTOLOGY, Issue 3 2010Øystein Fardal Fardal Ø, Linden GJ. Long-term outcomes for cross-arch stabilizing bridges in periodontal maintenance patients , a retrospective study. J Clin Periodontol 2010; 37: 299,304. doi: 10.1111/j.1600-051X.2009.01528.x. Abstract Background: Cross-arch bridges are used to stabilize teeth for patients with reduced periodontal support. Little is known about technical or biological complications, whether teeth and implants can be combined in this type of bridge and the long-term effects on tooth loss. Materials and methods: All patients treated in a specialist periodontal practice who received cross-arch stabilizing bridgework and were subsequently maintained for at least 7 years were included in the study. The patients were selected from all patients who underwent initial periodontal therapy after 1986 in a Norwegian periodontal practice. The bridges were assessed for biological and technical complications. Bridges retained by teeth or by a combination of teeth and implants were included in the study. Results: Ninety-four rigid fixed bridges (77 teeth supported, 17 teeth and implant supported) in 80 patients (46 females, 34 males) were observed for an average of 10 years (range 7,22 years). In four patients, a bridge became loose and had to be re-cemented, and in one case the metal framework of a bridge fractured and the bridge had to be remade. In total, eight abutment teeth were lost from five patients but no implant abutments were lost. Overall, a higher rate of tooth loss was observed for patients provided with stabilizing bridges compared with control maintenance patients not treated with bridgework (p<0.0001); however, the rates in both groups were very low. Conclusion: Cross-arch stabilizing bridges constructed for periodontal patients as part of their periodontal maintenance therapy had few complications and were associated with low rates of abutment tooth loss. Combining teeth and implants did not affect the performance of these bridges. [source] Failure Modes with Point Loading of Three Commercially Available Denture TeethJOURNAL OF PROSTHODONTICS, Issue 6 2008Andrew R. Moffitt DDS Abstract Purpose: A common problem associated with implant-supported prostheses is the fracture of denture teeth. This study was designed to compare the fracture modes of three denture teeth by compressive load at a 30° off-axis angle. Material and Methods: Three denture teeth (Vident Duostat, Ivoclar Vivadent, and Dentsply Trubyte) processed to two denture base processing systems [injection-molded (IM) SR-Ivocap system and compression-molded (CM) denture base resin] were evaluated. Each specimen was processed to a metal framework. Ultimate failure strength of each system when point loaded at a 30° off-axis angle was recorded, along with a visual inspection of each specimen. Results: The average load fracture for each group was (in N): Vident CM 1106.97 ± 223.20, Vident IM 1168.18 ± 322.52, Dentsply CM 1098.08 ± 286.32, Dentsply IM 1023.80 ± 282.45, Ivoclar CM 1616.98 ± 204.87, and Ivoclar IM 1373.54 ± 282.58. There was a significant difference between the groups and the Ivoclar CM group. The Ivoclar CM group had the highest average load force, and the Dentsply IM group had the lowest average load force. On average, the teeth within the groups fractured at a higher compression force than the average maximum occlusal force in natural dentition. Dentsply and Vident denture teeth fractured more horizontally, and the Ivoclar denture teeth fractured more vertically within the groups. There was no significant difference among the groups between the IM and CM processing methods. Conclusions: In the present in vitro study, all specimens were able to withstand 30° off-axis loading with the exception of one specimen. With these results, this would indicate that these denture teeth are able to withstand normal occlusal forces. [source] Load transfer characteristics of unilateral distal extension removable partial dentures with polyacetal resin supporting componentsAUSTRALIAN DENTAL JOURNAL, Issue 1 2009T Jiao Abstract Background:, To photoelastically examine load transfer by unilateral distal extension removable partial dentures with supporting and retentive components made of the lower stiffness polyacetal resins. Methods:, A mandibular photoelastic model, with edentulous space distal to the right second premolar and missing the left first molar, was constructed to determine the load transmission characteristics of a unilateral distal extension base removable partial denture. Individual simulants were used for tooth structure, periodontal ligament, and alveolar bone. Three designs were fabricated: a major connector and clasps made from polyacetal resin, a metal framework as the major connector with polyacetal resin clasp and denture base, and a traditional metal framework I-bar removable partial denture. Simulated posterior bilateral and unilateral occlusal loads were applied to the removable partial dentures. Results:, Under bilateral and left side unilateral loading, the highest stress was observed adjacent to the left side posterior teeth with the polyacetal removable partial denture. The lowest stress was seen with the traditional metal framework. Unilateral loads on the right edentulous region produced similar distributed stress under the denture base with all three designs but a somewhat higher intensity with the polyacetal framework. Conclusions:, The polyacetal resin removable partial denture concentrated the highest stresses to the abutment and the bone. The traditional metal framework I-bar removable partial denture most equitably distributed force. The hybrid design that combined a metal framework and polyacetal clasp and denture base may be a viable alternative when aesthetics are of primary concern. [source] Early Loading of Four or Five Astra Tech Fixtures with a Fixed Cross-Arch Restoration in the MandibleCLINICAL IMPLANT DENTISTRY AND RELATED RESEARCH, Issue 3 2002Bruno Collaert DDS ABSTRACT Background: A change in implant placement has emerged recently from two-stage to one-stage surgery and to earlier and even immediate loading of the fixtures. Purpose: The aim of this study was to verify whether four or five fixtures installed in the edentulous mandible were suitable for early loading with a cross-arch fixed restoration. Materials and Methods: In 25 consecutively treated patients (28,88 yr), four or five Astra Tech fixtures (Mölndal, Sweden) were installed in edentulous mandibles. During the same surgical procedure, the abutments were connected. An impression was taken immediately after surgery. All patients received a fixed prosthetic rehabilitation of 10 to 12 teeth made of a cast metal framework and acrylic teeth/gingiva within a month. The fixtures were followed up clinically and radiographically for 7 to 24 months. Bone level was measured from the most coronal point of the vertical part of the fixture to the most apical bone level mesially or distally. Results: No fixtures were lost during follow-up. No postoperative complications occurred. Radiographic analysis showed a mean bone level of 0.6 mm after 7 to 12 months. Fixtures followed up from 13 to 18 and 19 to 24 months showed a mean bone level of 0.7 mm. Around two fixtures, the bone level was found at the first implant thread. All other fixtures showed the bone level somewhere along the vertical unthreaded part of the fixture. Conclusions: Early loading within 1 month of four or five Astra Tech fixtures in the edentulous mandible is a predictable procedure for a follow-up period of 6 to 24 months. [source] | ||||||||||