Removable partial dentures

On one side, prosthodontic reconstructions compensate for the sequelae of negative changes in the oral cavity; on the other side, they often enhance or accelerate them. As a consequence of negative changes in the oral cavity over time, treatment planning for RPDs becomes highly complex. A set of reliable criteria is necessary for decision-making and problem management It appears that the majority of published data on RPDs does not depict high effectiveness of this treatment modality. From a strict point of view of evidence-based dentistry, the level of evidence is low if not missing for RPDs. Randomized controlled trials on RPDs are difficult to design, they are not feasible for some questions due to the complexity of the material, or may remain without clinical relevance. The literature rarely gives information on the denture design, tooth selection, and management of the compromised structural integrity of teeth. So far treatment outcomes with RPDs must be considered under the aspect of bias due to the bias in indication and patient selection for RPDs. Better clinical models should be elaborated with more stringent concepts for providing RPDs. This encompasses: risk analysis and patient assessment, proper indications for maintenance or extraction of teeth, strategic placement of implants, biomechanical aspects, materials, and technology. Although there is a tendency to offer fixed prostheses to our patients, this might change again with demographic changes and with an increase in the ageing population, an increase in their reduced dentition, and low socioeconomic wealth in large parts of the world.

Ethics in the provision of removable partial dentures

Aim: To investigate the construction of cobalt-chromium removable partial dentures by commercial private dental laboratories. Methods: Ninety master casts for fabrication of cobalt-chromium removable partial dentures were obtained from three commercial laboratories randomly selected. Casts were assessed for dental arch treated, Kennedy classification, cast surveying, denture design information provided by the dentist, and mouth preparation (rest seat, guiding plane and retentive area). Dental technicians answered a questionnaire regarding qualification of assisted dentists, monthly number of framework castings, and use of dental surveyor. Mouth preparation was compared among laboratories using Kruskal-Wallis test (α=0.05). Results: The percentage of Kennedy class I was 16%, class II 19%, class III 56%, and class IV 9%. The majority of master cats (51%) examined was sent to dental laboratories without any design information and did not comply with ethical guidelines in the provision of RPD. Approximately half of the casts were considered “inappropriate” for guiding planes and retentive areas. One of the laboratories presented all casts “inappropriate” for rest seat distribution (p<0.001). Conclusions: Mouth preparation frequently failed for guiding planes, retentive areas and distribution of rest seats. It is necessary to provide students with adequate clinical experience at the dental school environment, which will actually be carried into the practice of dentistry.

Ethics in the provision of removable partial dentures

Aim: To investigate the construction of cobalt-chromium removable partial dentures by commercial private dental laboratories. Methods: Ninety master casts for fabrication of cobalt-chromium removable partial dentures were obtained from three commercial laboratories randomly selected. Casts were assessed for dental arch treated, Kennedy classification, cast surveying, denture design information provided by the dentist, and mouth preparation (rest seat, guiding plane and retentive area). Dental technicians answered a questionnaire regarding qualification of assisted dentists, monthly number of framework castings, and use of dental surveyor. Mouth preparation was compared among laboratories using Kruskal-Wallis test (α=0.05). Results: The percentage of Kennedy class I was 16%, class II 19%, class III 56%, and class IV 9%. The majority of master cats (51%) examined was sent to dental laboratories without any design information and did not comply with ethical guidelines in the provision of RPD. Approximately half of the casts were considered “inappropriate” for guiding planes and retentive areas. One of the laboratories presented all casts “inappropriate” for rest seat distribution (p<0.001). Conclusions: Mouth preparation frequently failed for guiding planes, retentive areas and distribution of rest seats. It is necessary to provide students with adequate clinical experience at the dental school environment, which will actually be carried into the practice of dentistry.

Removal of a Partial Denture from the Esophagus with the Aid of an Endoscope

Swallowed prostheses have been described in the literature, and in some cases, the diagnosis can be challenging, especially if the partial or complete denture is metal-free. This article presents a case of a swallowed partial denture and points to the importance of early diagnosis. A man was admitted to the emergency room complaining of progressive breathing difficulty while presenting with an extra volume in his neck. After inconclusive image examinations, endoscopy under sedation was used to identify and retrieve the foreign object, which was a metal-free acrylic partial denture. Early diagnosis and the correct treatment can avoid serious sequelae, such as edematous reactions, mucosal infection, and necrosis. Patients should be scheduled for regular recall visits for evaluation of prosthesis fit and retention, condition of the abutments, and nocturnal wear. Int J Prosthodont 2010;23:339-341.

Relationship between squamous cell carcinoma of the anterior two thirds of the tongue and removable denture use - a pioneer study in a Portuguese

The aim of the study was to determine whether there is any relationship between the presence of removable dentures and squamous cell carcinoma of the anterior two thirds of the tongue in a Portuguese population. A retrospective cross-sectional study was conducted on patients with a biopsy-proven diagnosis of squamous cell carcinoma of the tongue, who were seen and treated at the Department of Head and Neck Surgery of the Portuguese Institute of Oncology 'Francisco Gentil', Lisbon, Portugal, during a 3-year period. Several factors were examined: gender, use of removable dentures, age, location of the lesion, and alcohol and tobacco consumption. One hundred and six cases were selected from the initial 151 cases, with a male:female ratio of 3:1 and the lateral borders being the most commonly affected site. The prevalence in both genders was between the sixth and seventh decade of life. Men were more likely to consume alcohol and tobacco than women, and no relationship was observed between denture use and presence of carcinoma of the tongue. In light of the data obtained, it may be considered that female use of a denture plays an important role, but it cannot be identified as a remarkable etiologic factor.

Evaluation of Stress Patterns Produced by Implant-Retained Overdentures and Implant-Retained Fixed Partial Denture

The purposes of this study were to photoelastically measure the biomechanical behavior of 4 implants retaining different cantilevered bar mandibular overdenture designs and to compare a fixed partial denture (FPD). A photoelastic model of a human edentulous mandible was fabricated, which contained 4 screw-type implants (3.75 x 10 mm) embedded in the parasymphyseal area. An FPD and 3 overdenture designs with the following attachments were evaluated: 3 plastic Hader clips, 1 Hader clip with 2 posterior resilient cap attachments, and 3 ball/O-ring attachments. Vertical occlusal forces of 100 N were applied between the central incisor and unilaterally to the right and left second premolars and second molars. Stresses that developed in the supporting structure were monitored photoelastically and recorded photographically. The results showed that the anterior loading, the overdenture with 3 plastic Hader clips, displayed the largest stress concentration at the medium implant. With premolar loading, the FPD and overdenture with 3 plastic Hader clips displayed the highest stresses to the ipsilateral terminal implant. With molar loading, the overdenture with 3 ball/O-ring attachments displayed the most uniform stress distribution in the posterior edentulous ridge, with less overloading in the terminal implant. It was concluded that vertical forces applied to the bar-clip overdenture and FPD created immediate stress patterns of greater magnitude and concentration on the ipsilateral implants, whereas the ball/O-ring attachments transferred minimal stress to the implants. The increased cantilever in the FPD caused the highest stresses to the terminal implant.

Overlay removable partial dentures for a patient with ectodermal dysplasia: A clinical report

The orofacial characteristics of ectodermal dysplasia include anodontia or hypodontia, hypoplastic conical teeth, underdevelopment of the alveolar ridges, frontal bossing, a depressed nasal bridge, protuberant lips, and hypotrichosis. Patients with this disease often need complex prosthetic treatment. The options for a definitive treatment plan may include fixed, removable, or implant-supported prostheses, singly or in combination. However, financial constraints and other priorities can prevent patients from choosing the most desirable treatment. This clinical report describes the diagnosis and treatment of ectodermal dysplasia in an 18-year-old man. The treatment included interim removable partial dentures fabricated to establish an acceptable therapeutic occlusal vertical dimension, followed by definitive overlay removable partial dentures and composite restorations.

Removable Partial Dentures: Use of Rapid Prototyping

The CAD/CAM technology associated with rapid prototyping (RP) is already widely used in the fabrication of all-ceramic fixed prostheses and in the biomedical area; however, the use of this technology for the manufacture of metal frames for removable dentures is new. This work reports the results of a literature review conducted on the use of CAD/CAM and RP in the manufacture of removable partial dentures.

Aesthetic rehabilitation of oligodontia in primary dentition with adhesive partial denture

The primary teeth are essential for bone development and establishment of the arches on occlusion. Thus, the congenitally absence of teeth may trigger a shift in the balance of the occlusion, promoting disharmony in the structures of the maxilla-mandibular system. However, some interventions are possible to be performed in these cases even in pediatric patients, to redirect growth, preventing growth deviations and reestablishing the aesthetic. The aim of this paper is to report the treatment of a 4-year-old child presenting congenitally absence of mandibular central and lateral incisors and maxilla lateral incisors, which consequently compromises aesthetics, occlusal function, and the development and the functional growth of the bones. The oral rehabilitation was performed with an adhesive partial denture, which was able to restore the aesthetic and the occlusal function, therefore being a viable alternative in the treatment of this patient of little age.

Quality of life and satisfaction of patients wearing implant-supported fixed partial denture: a cross-sectional survey of patients from Aracatuba city, Brazil

ObjectivesThe aim of this study was to evaluate the quality of life and satisfaction of patients wearing implant-supported fixed partial dentures.Materials &methodsA total of 106 patients were selected and submitted to clinical examination and collection of the demographic data for evaluation of the implant-supported fixed dentures conditions. All participants agreed to answer to the Oral Health Impact Profile (OHIP-EDENT) questionnaire and another questionnaire about satisfaction with the implant-supported prostheses. The patients were classified into the following three groups for statistical analysis: patients wearing splinted implant-supported prosthesis (E), patients wearing single implant-supported prosthesis (U), and patients wearing single implant-supported prosthesis associated with splinted prosthesis (E+U). Kruskal-Wallis test was used to compare the answers between the groups, and a logistic regression model was measured to verify the relation between variables of the patients and the questionaries'items.ResultsThere were significant differences among groups (P=0.006) for discomfort during surgery itself of the satisfaction questionnaire. The marital status, groups, and hygiene condition were significant mainly for physical pain item.ConclusionsIt was concluded that the patients presented high level of satisfaction and quality of life for the most of the items evaluated as well as the groups showed similar results.

Prosthetic rehabilitation of a patient after a partial mandibulectomy

The treatment of orofacial tumors may cause facial deformities by losses of structures that affect basic functions, i.e. feeding, speech, and the reduction of patient self-steam. A white male patient was diagnosed with epidermoid cancer on the mandibular alveolar ridge with infiltration staging IV A. The patient was submitted to a mandibulectomy associated with a complete extraction of mandibular teeth. For rehabilitation, a conventional denture for the mandibular arch and a removable partial denture for the maxillary arch were fabricated. A correct occlusal adjustment and a satisfactory amount of alveolar bone was favorable for conventional dentures of the prostheses bases improve their retention and stability. After one year of follow-up, the patient was adapted to the prostheses, satisfied with their retention, and reported an improvement on his feeding. The prosthetic rehabilitation of patients after a partial mandibulectomy is essential for their self-steam. Conventional dentures may have their retention and stability improved if they are well fabricated, recorded and have a balanced occlusion. A correct occlusal adjustment and an adequate retention of the prostheses bases may improve their retention and stability. Patients without xerostomy and with a satisfactory amount of alveolar bone may have a favorable prognosis for conventional dentures.

Design of removable partial dentures: a survey of dental laboratories in Greece

The aim of this study was to compare data on design and fabrication methods of removable partial dentures (RPDs) in two major cities in Greece. A questionnaire was sent to 150 randomly selected dental technicians. The participation rate was 79.3%. The anterior palatal strap, the lingual bar, and the Roach-type clasp arm designs were preferred. Half of the RPDs fabricated were retained using precision attachments. Differences between the two cities were observed in types of major maxillary connectors used, types of attachments and impression materials used, as well as the design of distal-extension RPDs. Postdoctoral education was found to have an impact on RPD fabrication. Despite the differences observed, design and fabrication of RPDs followed commonly used principles.

[Zirconia and removable partial dentures]

The present paper deals with the double crown technique in removable prosthodontics. New ceramic materials like zirconia are increasingly used in combination with CAD/CAM technologies for framework fabrication of fixed prosthesis, tooth- or implant-supported. However, zirconia is also a newly accepted material in removable prosthodontics. It replaces gold alloys for the fabrication of primary telescopic crowns. The Galvanoforming technology is preferably used to fabricate the secondary crowns. The combination of both techniques and materials results in a prosthetic reconstruction of high quality, optimum fit and good biocompatibility.

Removable dentures with implant support in strategic positions followed for up to 8 years

PURPOSE: The aim of this study was to analyze prosthetic maintenance in partially edentulous patients with removable prostheses supported by teeth and strategic implants. MATERIALS AND METHODS: Sixty patients with removable partial prostheses and combined tooth-implant support were identified within the time period from 1998 to 2006. One group consisted of 42 patients (planned group) with a reduced residual dentition and in need of removable partial dentures (RPDs) or overdentures in the maxilla and/or mandible. They were admitted consecutively for treatment. Due to missing teeth in strategic important positions, one or two implants were placed to improve symmetrical denture support and retention. The majority of residual teeth exhibited an impaired structural integrity and therefore were provided with root copings for denture retention. A few vital teeth were used for telescopic crowns. The anchorage system for the strategic implants was selected accordingly. A second group of 18 patients (repair group) wearing RPDs with the loss of one abutment tooth due to biologic or mechanical failure was identified. These abutment teeth were replaced by 21 implants, and patients continued to wear their original prostheses. The observation time for planned and repair groups was 12 months to 8 years. All patients followed a regular maintenance schedule. Technical or biologic complications with supporting teeth or implants and prosthetic service were registered regularly. RESULTS: Three maxillary implants were lost after loading and three roots with copings had to be removed. Biologic problems included caries and periodontal/peri-implant infection with a significantly higher incidence in the repair group (P < .05). Technical complications with the dentures were rather frequent in both groups, mostly related to the anchorage system (matrices) of root copings and implants. Maintenance and complications were observed more frequently in the first year after delivery of the denture than in the following 3 years (P < .05). No denture had to be remade. CONCLUSIONS: The placement of a few implants allows for maintaining a compromised residual dentition for support of RPDs. The combination of root and implant support facilitates treatment planning and enhances designing the removable denture. It also proves to be a practical rescue method. Technical problems with the anchorage system were frequent, particularly in the first year after delivery of the dentures.