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Concept: Removable partial denture

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The frequent instability of mandibular removable complete dentures affects patient Oral Health Related Quality of Life (OHRQoL). An innovative therapeutic strategy used to improve stability involves placing four symphyseal mini-implants. This study was aimed at assessing OHRQoL over time in subjects in which mini-implants were placed and exploring if certain parameters could predict the evolution of their OHRQoL. The OHRQoL of subjects with dentures was assessed using the Geriatric Oral Health Assessment Index (GOHAI) before (T0), 2-6 months (T1), twelve months (T2) and twenty-four or more months (T3) after mini-implant setting. Age, gender and chewing ability were tested as explanatory variables for the change in OHRQoL with time. Thirteen women and six men were included (mean age: 69 ± 10 years). After treatment, mean GOHAI scores at T1, T2 and T3 increased significantly (p < 0.001). The GOHAI-Add mean score was not affected by age or gender. Baseline chewing ability impacted the "functional" and "pain and discomfort" fields of the mean GOHAI scores (p < 0.05). The OHRQoL quickly improved after mini-implant placement in complete denture wearers and then stabilized over time. Baseline chewing ability can be used as a predictive parameter of OHRQoL.

Concepts: Scientific method, Medicine, Future, Dentistry, Dentures, Removable partial denture, Currying

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The first-line treatment of non-restorable traumatically injured or carious deciduous teeth is extraction which may be a curse for the future dentition as well as social activity of a child. Various therapeutic modalities from removable partial dentures to fixed space maintainer can be used for replacement of such lost teeth. Two types of fixed aesthetic space maintainers for replacing premature loss of maxillary deciduous incisors in 4-year-old children are discussed.

Concepts: Teeth, Tooth development, Maxillary central incisor, Canine tooth, Removable partial denture

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Purpose: To analyze masticatory function after a short adaptation period relative to occlusal support length reduction in free-end removable partial denture (RPD) wearers. Materials and Methods: Twenty-three patients (55.2 ± 8.4 years) were rehabilitated with maxillary complete and mandibular free-end RPDs extending to the second molars. Five occlusal support length conditions were determined by removing artificial teeth from the RPDs: full occlusal support (control); occlusal support to the first molars, second premolars, and first premolars; and no occlusal support. To explore a probable short-term adaptation to occlusal support length reduction, participants wore their dentures at each condition for a period of 1 week before starting masticatory function assessment. For this purpose, masticatory performance, masticatory efficiency, chewing rate, selection chance, and breakage function were evaluated at each condition using the sieving method. Data were analyzed using repeated-measures ANOVA and post hoc Dunnett tests (α= 0.05). Results: Masticatory performance and masticatory efficiency for 2 to 4 mm particles under the condition of occlusal support to the first molars and second premolars were similar to control values (p > 0.05). Masticatory efficiency relative to particles smaller than 2 mm was also seen at the condition of support length to the first premolars (p > 0.05). Chewing rates showed adaptation only at the condition of support length to the first molars (p > 0.05). A similar trend was noted for the selection chance of 8-mm particles, and breakage function for 8- and 2.4-mm particles (p > 0.05). Conclusion: After a 1-week adaptation period to free-end RPDs with occlusal support lengths reduced to the premolars, participants were able to achieve adequate masticatory function.

Concepts: Dentures, Removable partial denture

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If prosthodontic treatment is considered after periodontal therapy, the questions arise i) does prosthodontic treatment affect the treatment outcome of the dentition in general and ii) which type of prosthesis is related to best treatment outcome of abutment teeth? Our goal was to compare long-term tooth loss after comprehensive periodontal therapy in patients with or without prosthodontic treatment. Ninety patients' charts with a total of 1937 teeth who had received comprehensive periodontal treatment 5-17 years ago by the same periodontist were retrospectively evaluated. Sixty-five patients received fixed dental prostheses (FDP; n = 29) and/or removable partial dentures anchored with clips (RPDC; n = 25) or double crowns (RPDD; n = 25). Twenty-five patients were also periodontally compromised but treated without prosthodontic treatment and served as a control group. A total of 317 teeth and 70 abutment teeth were lost during 9·7 ± 4·1 years of observation. Thereof, 273 teeth and 48 abutment teeth were lost due to periodontal reasons. Mean tooth loss amounted to 1·2 ± 1·5 (controls) and 4·4 ± 3·4 (partial dentures). Abutment tooth loss was 0·4 ± 1·1 (FDP), 1·0 ± 1·2 (RPDC) and 1·3 ± 1·0 (RPDD). Poisson regressions identified prosthodontic treatment, age, socio-economic status, diabetes mellitus, mean initial bone loss and aggressive periodontitis as factors significantly contributing to tooth loss. Age, diabetes and non-compliance contributed to abutment tooth loss. Not considering biomechanical factors, patients with prosthodontic reconstructions under long-term supportive periodontal therapy were at higher risk for further tooth loss than patients without prostheses. Not only the type of partial denture but also the patient-related risk factors were associated with abutment tooth loss.

Concepts: Diabetes mellitus, Periodontology, Periodontitis, Prosthesis, Oral hygiene, Dentures, Removable partial denture, Prosthodontology

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In dental applications, precision attachments have been used to retain removable partial dentures (RPDs) for several decades. Various types of extracoronal attachments are commonly used in combination with fixed partial dentures and RPDs to achieve retention and stability. Fracture of the framework, fracture of the roots or teeth, and irretrievable decrease of retention are common reasons for a failed attachment-retained RPD. Another complication of metal ceramic crowns with precision attachment is decementation of the crowns. When fixed components of the attachment-retained RPD fail, the traditional treatment approach requires remaking both the fixed and removable components of the attachment-retained RPD. This technique describes retrofitting of a metal ceramic crown to a resilient attachment-retained RPD.

Concepts: The Roots, Crown, Oral hygiene, Dentures, Restorative dentistry, Removable partial denture, Prosthodontology, Precision attachment

25

Several clasp types are used in distal extension removable partial dentures. In some cases the terminal abutments have only distal retentive undercuts that can be occupied by bar clasps; however, bar clasps may be contraindicated with no suitable alternative. This article presents a reasonable solution by introducing a new clasp design as a modification to the well-known RPA clasp. The design includes a mesial rest, proximal plate, and buccal retentive arm arising from the rest and extending to reach the distal retentive undercut.

Concepts: The Terminal, Removable partial denture, 2004 films

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Removable partial dentures (RPDs) are used to restore missing teeth and are traditionally fabricated using the lost-wax casting technique. The casting process is arduous, time-consuming, and requires a skilled technician. The development of intraoral scanning and 3D printing technology has made rapid prototyping of the RPD more achievable. This article reports a completed case of direct fabrication of a maxillary RPD metal framework (Kennedy Class I) using intraoral scanning and 3D printing techniques. Acceptable fit and satisfactory clinical outcome were demonstrated. Intraoral scanning and 3D printing for fabrication of the RPD metal framework is a useful alternative to conventional impression and casting techniques, especially for patients suffering from nasal obstruction or intolerance.

Concepts: Dentures, Removable partial denture, Rapid prototyping

0

The aim of the study was to compare the retentive behaviors of double crowns with different designs and material compositions before and after artificial aging.

Concepts: Dentures, Removable partial denture

0

Selective laser melting (SLM) technology was recently introduced to fabricate dental prostheses. However, the fatigue strength of clasps in removable partial dentures prepared by SLM still requires improvement. In this study, we attempted to improve the fatigue strength of clasps by adding support structures for overhanging parts, which can generally be manufactured at an angle to be self-supporting. The results show that the fatigue strength of the supported specimens was more than twice that of unsupported specimens. Electron back-scattered diffraction analysis revealed that the supported specimens exhibited lower kernel average misorientation values than the unsupported specimens, which suggested that the support structure reduced the residual strain during the SLM process and helped to prevent micro-cracks led by thermal distortion. In addition, the supported specimens cooled more rapidly, thereby forming a finer grain size compared to that of the unsupported specimens, which contributed to improving the fatigue strength. The results of this study suggest that the fatigue strength of overhanging parts can be improved by intentionally adding support structures.

Concepts: Better, Improve, Laser, Fracture mechanics, Addition, Fatigue, Dentures, Removable partial denture