The development of a method for functional assessment of dentures.

AIMS: To design and validate a method of assessing complete dentures from a functional standpoint. SUBJECTS: A random sample of 40 complete denture wearers took part in the study. SETTING: A university clinical department of prosthetic dentistry. INTERVENTION: We undertook a pilot study to refine the protocol and criteria. All participants and their dentures were examined by two authors independently, with no prior knowledge of the patients' complaints. DESIGN: We defined nine clinical factors of functional quality and applied criteria with binary scoring. We analysed the scores for these factors for inter-rater reliability. RESULTS: The method proved simple to apply and took less than 5 minutes to complete. The inter-examiner agreement for all factors was 86% to 100% giving Kappa scores of 0.64 to 1.00 (all Good or Very Good). CONCLUSIONS: This study successfully demonstrates that the technique, which we call the Functional Assessment of Dentures (FAD), can give good inter-examiner reliability. It can therefore be used separately as a routine diagnostic tool and to investigate the relationship between denture qualities and functional 'outcome' such as difficulty eating or dietary selection.

After Kennedy...

Edward Kennedy's book Partial Denture Construction was published in 1928. A number of the principles that he advocated are still taught, albeit in a modified manner, although the background reasoning supporting those principles has changed somewhat. This paper highlights some of those principles and makes the point that several of them do not appear to have achieved wide acceptance over 70 years later.

Initial prosthetic treatment.

This article describes measures designed to provide short-term solutions to existing RPD problems and to establish an optimum oral environment for the provision of definitive prostheses.

Tooth preparation.

This final article in the series describes the modification of teeth to improve their shape for the support and retention of RPDs.

Connectors.

This article describes the types and functions of connectors for RPDS. It also considers the relative merits and limitations of these connectors.

Indirect retention.

This article explains the mechanism of indirect retention for RPDs and discusses the factors which determine its effectiveness. Examples are given of designs which incorporate indirect retention.

A study of the use of photographs for denture tooth selection.

PURPOSE: The aim was to examine a method described by Wehner et al for calculating the width of a missing central incisor using preextraction photographs. MATERIALS AND METHODS: Three photographic views were obtained for each of 30 dentate subjects: full face, oblique, and reduced-size full face. The width of the maxillary right central incisor (MR1) was calculated using a formula. The difference between the actual width and calculated width of MR1 was determined for each subject. The median difference and interquartile range were determined because the data were skewed. RESULTS: The width of MR1 calculated using the larger full-face view was typically smaller than the actual width, with a median difference of -0.18 mm. The interquartile range of the difference was from -0.42 to 0.05 mm. For both the oblique and reduced-size views, the calculated width was typically larger, with a median difference of 1.19 mm with an interquartile range from 0.82 to 1.76 mm and a median difference of 0.84 mm with an interquartile range from 0.59 to 1.41 mm, respectively. CONCLUSION: The technique described by Wehner et al is of proven value in calculating the width of a central incisor when the only available evidence is a preextraction photograph. However, it is of value only when the photograph is a full-face portrait of sufficient size.

Communication between the dentist and the dental technician.

Factors contributing to good RPD design are described, including the respective inputs of the dentist and dental technician. Poor communication in current practice is reported and an appropriate format for a work authorization presented.

The removable partial denture equation.

This article describes the benefits and risks of providing RPDs. It emphasises the importance of co-operation between the dental team and patient to ensure that the balance of this 'equation' is in the patient's favour.

Removable partial dentures. 1. Need and demand for treatment.

This article considers first, factors influencing the need and demand for removable partial dentures (RPDs) and second, the particular requirements and problems of elderly patients related to such treatment.

Retention.

This article describes the mechanisms for retaining RPDs and considers the different types of direct retainer. The factors influencing the effectiveness of retentive clasps and governing the choice of clasp are discussed.

A system of design.

This article describes a method of building RPD components into an effective design and indicates how the details of the design can be communicated clearly to the dental technician.

How well are complete dentures copied?

OBJECTIVE: To assess how accurately the same set of complete dentures could be copied by 12 different laboratories. DESIGN: A prospective study. SETTINGS: Completed by commercial laboratories used by GDPs in England (1996). Results were analysed and controlled by a university department. SUBJECTS (MATERIALS) AND METHODS: The master set was constructed to include a midline diastema and a bilateral posterior crossbite. Twelve sets of silicone moulds of the master denture were prepared. GDPs selected commercial laboratories of their choice to receive the work. MAIN OUTCOME MEASURES: All stages of the work were compared with the master dentures by returning them to a specially adapted articulator. Analysis was completed using preset criteria. RESULTS: Only five of the returned copies were considered to have both good quality acrylic resin work and clear details of the teeth in wax. Only four cases reproduced the diastema. After processing, the occlusal vertical dimension had been increased in eight of the cases and the bilateral crossbite had been eliminated in all cases. CONCLUSIONS: None of the final copy dentures were considered an accurate copy of the master dentures. There is considerable scope for further training of dental technicians in this important technique.

Removable partial denture design in Alberta dental practices.

Studies published in the dental literature have found, all too frequently, that dentists do not pay adequate attention to the design of cast removable partial denture frameworks. This study investigated removable partial denture design in Alberta dental practices. The authors considered various issues related to surveying, partial denture design, and provider education, as well as the possible collaboration of clinical dentistry with denturism in removable partial denture treatment. Although the study found that a significant proportion of Alberta's dentists get involved in designing the cast framework, relatively few undertake surveying. Instead, surveying tends to be deferred to dental technicians. As was the case in other studies, no clear reason for this trend emerged, and it appeared to be unrelated to remuneration or time utilization issues. Responding dentists perceived that their undergraduate education was adequate for providing removable partial denture care. The study also identified a need for small, hands-on continuing education courses. About half of the respondents indicated that it is appropriate for dentists to collaborate with denturists on complete denture care. However, very few respondents considered it appropriate to refer to, or collaborate with, denturists in removable partial denture care.

The development of a simple test method to characterise the compliance and viscoelasticity of long-term soft lining materials.

A simple test, based on the measurement of depth of penetration, has been devised to characterise long-term soft lining materials. Inter-laboratory testing has shown the method to be reproducible and to be capable of comparing and contrasting the compliance and viscoelastic behaviour of commercially available materials. Additional results emphasise the point that it is imperative to control the testing temperature, especially for the soft acrylic materials.

Preparation of guide planes using a reciprocating handpiece.

A reciprocating handpiece and attachments have been found effective in preparing guide planes prior to the construction of removable partial dentures. A comparison was made of the enamel surface prepared using the reciprocating handpiece and a conventional rotary handpiece. Two-stage and three-stage techniques for each handpiece were compared. Scanning electron micrographs showed that a smoother surface was created by the reciprocating handpiece.