STATEMENT OF PROBLEM Current demographic information on the number and types of removable partial dentures is lacking in the prosthodontic literature. PURPOSE This study was designed to investigate patterns of tooth loss in patients receiving removable partial dentures (RPDs) in eastern Wisconsin. MATERIAL AND METHODS Digital images (1502) of casts at 5 dental laboratories in eastern Wisconsin were collected. Any prescription requesting fabrication of a removable partial denture was photographed twice. The first photograph was made immediately upon arrival at the laboratory, while the second photograph was made immediately before being returned to the prescribing dentist for the first time. A calibrated investigator analyzed all the photographs for Kennedy Classification, type of RPD, major connector, and other details. Data were analyzed with descriptive statistics. Fisher's exact test was used to confirm repeatability. RESULTS Kennedy Class I was the most common RPD with a frequency of 38.4%. More than 40% of prescriptions had no design input from the dentist. One in 3 RPDs used acrylic resin or flexible frameworks. One in 5 RPDs had no rests. The horseshoe major connector was the most common maxillary major connector, while the lingual plate was the most common in the mandible. CONCLUSIONS RPDs remain a common prosthodontic treatment in this region. Non-metal RPD frameworks are a common treatment type and rarely include rests. These data indicate a changing partially edentulous patient population and a variable commitment to standard levels of prosthodontic care.

Missing teeth can be replaced using any of a number of methods. Patients may choose to replace missing teeth with a prosthesis that is either removable, fixed, or retained with implants. When it is necessary to replace anterior or posterior teeth, a properly designed and fabricated rotational path removable partial denture can be both successful and esthetically pleasing to the patient. However, while a patient's functional and esthetic needs can be met successfully, rotational path removable partial dentures can be more demanding for the laboratory technician to fabricate and for the dentist to seat in the mouth. Rotational path removable partial dentures frequently are overlooked as a viable means of treating missing teeth. This article reviews the principles of rotational path removable partial dentures, as well as their categories, advantages, and disadvantages, in the hope that more dentists will consider them when the need arises.

Removable partial dentures (RPD) are an effective and affordable treatment option for partial edentulism. If the main reason for seeking treatment is the need for improved aesthetics, treatment should be geared towards achieving this goal. This article is the result of a literature study on aesthetic clasp design for the conventional RPD. In this context, the position of the clasp on the tooth, clasp types, clasp material and alternative methods of retention are reviewed. Although published in reputable journals, the authors report that many articles published on this subject are of a descriptive nature and lack scientific evidence. Therefore, clinicians are encouraged to be critical in their interpretation of literature and the application of published information in their clinical practices.

The purpose of this study was to evaluate the degree and amount of movement of the abutment tooth and denture base influenced by the direct retainer of distal extension removable partial denture and the location of functional loading, then to suggest direct retainer design with minimal adverse effect and with optimum functional loading location for residual tissue. The displacement of the abutment tooth and inclination of the denture base were determined, with 30 N as work load utilizing simulation model and strain gauge system, about two types of direct retainers with mesial or distal rest and nine loading points on denture base. Displacement and inclination was determined with the one-way analysis of variance and Scheffe's multiple test was performed. The results revealed that type of direct retainer influenced on the magnitude rather than direction of the abutment tooth displacement. The distal displacement of abutment tooth was significantly less in Type M clasp (with mesial rest and connection) than in Type D clasp (with distal rest and connection)(p<0.05). The location of loading points influenced both of the magnitude and direction of the abutment tooth and denture base movement. Posterior and lingual loading resulted in significantly distal displacement of abutment tooth (p < 0.05).

The purpose of a classification for removable partial dentures (RPDs) is to simplify identification and enhance its teaching. A classification also allows a longitudinal comparison of various classes of RPDs to determine whether the teaching of RPD design is consistent with the relative frequencies of RPD use. This study surveyed the types of removable partial dentures being fabricated in a regional dental laboratory and compared these findings with data from previous studies. Results indicate that mandibular RPDs are more common than maxillary RPDs and the class I mandibular RPD is the most common type of RPD for either dental arch. A palatal strap was the most frequently used maxillary major connector and a lingual bar was used three times more often than a lingual plate in the mandibular arch. Cast circumferential clasps were used twice as often as RPI clasp designs. The percentage of Kennedy class I RPDs was 40%, class II 33%, class III 18%, and class IV 9%. Comparisons with a previous study indicate the percentage of Kennedy class II has increased, whereas class I, class III and class IV RPDs have not changed significantly. Findings of the study indicate that the frequency of use of the various types of RPDs have changed in the past 30 years.