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Concept: Dentures

138

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

28

A patient exhibited severe abrasion of resin posterior denture teeth including perforation of the denture base. New dentures were provided to explore the application of zirconia teeth for complete dentures. [Correction added to online publication 07 November 2012: “Zirconium” corrected to “Zirconia”.] Traditional denture procedures were combined with fixed prosthodontic CAD/CAM procedures to fabricate custom-designed four-tooth posterior segments in hollow crown form to reduce weight and with a retentive form for interlocking to the denture base. The new dentures were successful in reducing wear of the denture teeth over the short-term follow-up period.

Concepts: Nitrogen, Teeth, Tooth enamel, Dentures, Zirconium dioxide, Prosthodontology, Prosthodontics

27

This article describes a multidisciplinary approach combining surgical and prosthodontic treatment of a completely edentulous patient who presented with a severe skeletal class III relationship and was diagnosed as American College of Prosthodontists Prosthodontic Diagnostic Index (ACP PDI) class IV. The use of a complete denture serving as diagnostic tool, surgical guide, and definitive restoration is presented. Computer-aided surgical simulation was used to achieve an accurate diagnostic and surgical plan. Maxillary Lefort class I and mandibular sagittal split osteotomy surgical treatment was performed to correct arch discrepancy. The surgical procedure demonstrated a clinically acceptable maxillomandibular relationship and stability. The patient was satisfied with the esthetics and demonstrated improved oral function following prosthesis insertion.

Concepts: Diagnosis, Dentures, Class III railroad, Prosthodontics

27

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

27

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

26

The study was undertaken to evaluate the reliability of different facial measurements for determination of vertical dimension of occlusion in edentulous subjects using accepted facial dimensions recorded from dentulous subjects. The hypothesis was that facial measurements can be used to obtain the vertical dimension of occlusion for edentulous patients where no pre-extraction records exist. A total of 180 subjects were selected in the age groups of 50-60 years, consisting of 75 dentate male and 75 dentate female subjects for whom different facial measurements were recorded including vertical dimension of occlusion and rest, and 15 edentulous male and 15 edentulous female subjects for whom all the facial measurements were recorded including the vertical dimension of rest and occlusion following construction of upper and lower complete dentures. The left outer canthus of eye to angle of mouth distance and the right Ear-Eye distance were found to be as valuable adjuncts in the determination of occlusal vertical dimension. The Glabella-Subnasion distance, the Pupil-Stomion distance, the Pupil-Rima Oris distance and the distance between the two Angles of the Mouth did not have a significant role in the determination of the occlusal vertical dimension. The vertical dimension can be determined with reasonable accuracy by utilizing other facial measurements for patients for whom no pre-extraction records exist.

Concepts: Male, Dimension, Psychometrics, Real number, Angle, Dentures, Cartesian coordinate system, Vertical dimension of occlusion

26

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

26

Restoring worn anterior mandibular teeth is a challenge, especially when teeth are small, esthetics are a concern, the long-term prognosis is questionable, and/or patient finances are an issue. This article describes an alternate treatment for a patient with a collapsed bite, missing posterior mandibular teeth, an ill-fitting complete maxillary denture with poor esthetics, and irregular, worn mandibular anterior teeth.

Concepts: Mandible, Dentures

26

Abstract The objective of the present study is the evaluation of the comprehensive 5-year results of fixed mandibular dentures fabricated from metal-acrylic or metal-ceramics according to the ‘All-on-4'™ protocol. Twenty-seven patients that received immediately loaded 'All-on-4'™ fixed mandibular dentures in 2005 were included in the study, and they were evaluated up to 5 years after denture integration. Endpoints were chosen in accordance with the 2007 Pisa consensus and included bone resorption, the Oral Health Impact Profile (OHIP), the Sulcus Fluid Flow Rate (SFFR), and prosthodontic complications. The initial situation in both groups was largely identical. Bone loss remained under 2 mm after 5 years in all implants and showed no group difference. The SSFR showed a gradual increase in both groups, and acrylic-bearing implants showed a substantially and significantly higher flow rate from the third year onward. The subjective improvement as expressed by the OHIP score was immediate and dramatic, and it showed no group differences. All acrylic restorations showed some extent of abrasion, and veneer fractures occurred in 4 patients (28.6%). Besides a single fracture of a fixation screw, there were no prosthetic complications in patients with ceramic suprastructures. According to bone loss and subjective outcome, acrylic and ceramic suprastructures apperared to be equivalent after 5 years; however, sulcus flow and prosthodontic complications suggest that the economic advantage of acrylic dentures may be specious. The rational choice of implant suprastructures requires comprehensive, long-term observation. Short-term economical benefits might be cancelled out in the long run.

Concepts: Time, Bone, Bone fracture, Fracture, Fluid dynamics, Economics, Dentures, Prosthodontics

25

To evaluate esthetic perceptions based on tooth exposure when smiling of patients wearing complete dentures by evaluators in different age groups.

Concepts: Dentures