Joseph E. Grasso

Effect of denture adhesive on the retention and stability of mixillary dentures

This study used quantitative methods to measure the effects of a denture adhesive on the retention and stability of the maxillary denture. Denture movements were measured on 20 patients during standardized chewing, swallowing, and speaking activities, first with no adhesive, and then at 0, 2, 4, 6, and 8 hours after application of an over-the-counter cream adhesive. The major findings were that the denture adhesive produced a statistically significant improvement in the retention and stability of the maxillary denture during the various chewing, swallowing, and speaking activities, for up to 8 hours; there were no statistically significant differences in improvement between a poorly fitting and well-fitting denture; and patients were able to produce significantly greater levels of incisal bite force with the use of the adhesive.

Professional attitudes toward denture adhesives: A Delphi Technique survey of academic prosthodontists

STATEMENT OF PROBLEM The use of denture adhesives and their role in prosthodontics has been an intriguing and conflicted topic, both in clinical practice and dental education. PURPOSE This study generated discussion, and if possible, obtained a consensus on a series of issues related to denture adhesives among a group of leading academic prosthodontists. MATERIAL AND METHODS The Delphi Technique survey method was used. It consists of a series of survey questionnaire rounds to a panel of experts to either develop a consensus (>70% agreement) or to clarify the reasons for multiple schools of thought on a topic. A 24-item Delphi questionnaire was sent to an expert panel that consisted of a 33% regionally stratified random sample of program directors of undergraduate complete denture courses in US dental schools. The 5 major topic areas on denture adhesives addressed by the questionnaire items were (1) general perceptions, (2) specific clinical uses/misuses, (3) patient education, (4) inclusion in dental curricula, and (5) overall opinions of utility. RESULTS Of the 18 randomly selected panelists, 94% (n = 17) agreed to participate, with either 16 or 17 fully participating in each of the 3 survey rounds. The panel achieved consensus and clearly concluded that denture adhesives: (1) are a useful adjunct in denture prosthesis services, having specific roles in both the fabrication and postinsertion phases; (2) had the potential for misuse, both by dentists and by patients; and (3) should be an integral part of patient education for all denture patients and of the undergraduate dental curriculum. However, the panel was unable to achieve consensus on whether denture adhesives should be used at the postinsertion phase for immediate denture patients and whether, on the whole, they were a beneficial adjunct in denture patient management (59% agreed they were). The panelists also clearly expressed their concerns that neither dentists nor patients should use denture adhesives as a substitute for either good clinical practices or proper denture maintenance routines. CONCLUSIONS This panel of leading academic prosthodontists concluded that denture adhesives are a useful adjunct in denture prosthesis services, with specific roles in both fabrication and postinsertion phases. They also indicated that only through education, for dentists and patients, would the dual goals of maximizing the beneficial aspects of denture adhesive use while minimizing the misuse of denture adhesives be achieved.

The effects of age and full palatal coverage on oral stereognostic ability

A number of studies have investigated the oral sensory abilities of denture wearers. Many techniques have been utilized, including discriminations of thickness,’ hardness,’ texture,’ size,’ oral stereognosis ability,,‘-” and oral manipulative ability.‘+ I2 These studies have had inconsistent results, with some investigators reporting significant alterations in oral sensory abilities and others finding no such changes. Any reported change in oral sensory ability may be confounded by a number of variables not specifically related to the ability in question. One such factor is the test itself, which may not be adequately sensitive to detect altered oral sensory function. For example, in evaluating discriminative ability for hardness,’ it was possible to discriminate clearly between denture wearers and nondenture wearers when testing with hard rubber disks but not with soft rubber disks. Another major variable that has not been adequately controlled in previous studies of oral sensory ability is age. Most denture wearers are older, and sensory discrimination is highly age dependent. I.‘, ‘-+ A third factor which must be considered is the role of palatal receptors in the performance of the specific task being tested. Numerous studies of subjects with abnormal oral anatomy have suggested that the palate plays a significant role in oral sensory tasks, including stereognostic ability. Specifically, patients with abnormal palatal vaults secondary to gonadal dysgenesis and pseudohypoparathyroidysm’5, “I consistently demonstrate abnormal oral stereognostic ability. Some evidence also suggests that patients

Retention and stability of the maxillary denture during function

The objectives of this study were to provide a quantitative account of the extent to which the maxillary complete denture moves during function (chewing, swallowing, and speech production) and to determine whether differences in movement occur as a function of denture fit. A total of 24 patients were studied, 12 with poorly fitting dentures and 12 with well-fitting dentures. Denture movements were measured with a Myotronics kinesiograph that tracked the movements of a small magnet attached to the inferior surface of the denture. Results indicated that denture movement was greatest for the two chewing activities; varied extensively from individual to individual; and that there were no statistically significant overall movement effects as a function of fit. It was concluded that all maxillary dentures are subject to movements in all directions, but that the degree of movement is related more to the individual denture wearer than it is to the fit of the denture.

Bend testing of wrought wire removable partial denture alloys

The flexibility of the wrought wire clasp is related to a number of factors, including the type and gauge of the alloy. The purpose of this study was to compare the bend behavior of five wrought wire alloys used in removable partial dentures. The alloys and their gauge diameters (in millimeters) were Ticonium (18, 19, 20), platinum-gold-palladium (18, 19), Wironium (18, 20), Jelenko Standard (18, 19, 20), and Denture Clasp (18, 19, 20). A total of 12 to 15 samples of each dental alloy were tested. Three-point bending was performed on a servohydraulic testing system controlled by a computer at 1.00 mm/sec until fracture or actuator contact occurred. Maximum stress and elastic modulus in bending were determined for each gauge diameter. Analysis of variance and post hoc Scheffe statistical analyses revealed significant maximum stress and elastic modulus in bending differences for different alloys of the same gauge and for different gauges of the same alloy. The choice of material and the gauge diameter significantly influenced the mechanical property of bending for wrought wire removable partial denture alloys. The Ticonium alloy had the greatest elastic modulus (stiffest) at all levels and the Denture Clasp and the Jelenko Standard alloys had the lowest elastic modulus (most flexible). These data indicate that knowledge of the bending properties of an alloy is equally as important as the gauge size when selecting a wire clasp.

Augmentation of the atrophic maxilla with interpositional autogenous bone grafts

Extreme ridge atrophy is a significant problem when it occurs in the maxilla, since inadequate denture function, as well as poor facial aesthetics, commonly result. Use of the Le Fort I osteotomy of the maxilla with interpositional iliac cortico-cancellous bone grafts is a predictable method of ridge augmentation in severe cases. In our experience, secondary vestibuloplasty has not been necessary prior to construction of new prostheses. Patient satisfaction has been excellent.

Light-cured resin for post patterns

A method of using light-cured acrylic resin as an alternative to the use of chemically-cured acrylic resins with elastomeric impressions for direct post patterns is presented. The GC Unifast LC acrylic resin is a powder/liquid type resin cured by exposure to visible light. The polymerization process has four stages before final curing: slurry, stringy, dough-like (plastic), and rubber-like (elastic). Advantages over current direct and indirect procedures include ease of manipulation of the material and no change in laboratory handling procedures. While in the dough-like state, the material can be contoured. In the rubber-like state, it is flexible to disengage from minor undercut areas.