Showing papers in "Journal of Prosthetic Dentistry in 1969"

Study of need for esthetics in dentistry

Abstract: T he literature contains numerous documented articles showing the need for treatment of caries and missing teeth. l-l5 However, it is apparent that people cannot enjoy complete social and mental well-being if their mouths are esthetically displeasing. I6 Nevertheless, there is an absence of material related to patient attitudes and desires for esthetic treatment. For this reason, a preliminary two-year study on esthetic motivation was undertaken. The group that was chosen for the study might be more conscious of esthetics than the average population. Sixty young ladies, ages 17 to 25, who were finalists for the 1966 and 1967 Miss Atlanta Pageants were surveyed. The girls were not given advance notice of the purpose or method of doing the survey.

Tooth-supported complete dentures: An approach to preventive prosthodontics

Abstract: The concept of tooth support for complete dentures permits the dentist to assume a significant role in preserving natural teeth and supporting structures. In many instances, teeth that would otherwise be removed can be maintained to help support complete dentures. Frequently, only one natural tooth can successfully help support a denture. A method for constructing tooth-supported complete dentures has been described, and the advantages and disadvantages have been discussed. Tooth-supported complete dentures are a valid approach to preventive prosthodontics and a valuable part of the practicing dentist's armamentarium.

The Cornell Medical Index as a prognostic aid for complete denture patients

Abstract: A population of 402 complete-denture patients has been evaluated. Postinsertion adjustments and the patient satisfaction score were measured against the patients Cornell Medical Index score. No correlation was established between postinsertion adjustments and CMI scores. A definite correlation was established, however, between increase in total CMI score above 25 and decrease in patient satisfaction. Further, a correlation was also established between a score of three to six on page 4 of the CMI and decreased patient satisfaction. There is evidence to support the value of education of complete-denture patients concerning the relationship of emotional problems and denture problems.

The dental polymer implant concept

Abstract: lh e replacement of man’s wornout or depleted parts with human or animai tissues or synthetic materials has been in man’s mind and imagination for centurks. In the early 1900’s, Alexis Carrel1 transplanted every major organ in animals. His famous two-headed dog was proof that transplant failures were not the result of surgical or technical difficulties. The built-in immune mechanism, a specificity that permits the prevention oi certain diseases by vaccination, also acts to prevent the success of transplants, and immunologic rejection results. This is a fundamental biologic reaction and was adequately demonstrated by the outstanding research of Medawar’ on rabbit skin transplants. He demonstrated that there was an immunization of the animal with the first graft and subsequent accelerated rejection of the second graft. It wab now clear that homologous and heterologous transplants failed due to an immunologic response. Transplant failures result from the ability of the host to identif) another tissue as containing a foreign protein and to be able to reject this tissue through the development of specific antibodies. Lymphocytes are instrumental in this phenomenon, since they are responsible for the elaboration of antibody. To overcome this, scientists have tried to control the immune response bysuppressing the bone marrow by the use of radiation. globulins, immunosuppressivt drugs, and cortisone-type drugs. All these methods seriously endanger the life of the transplant recipient. placing him in a delicate balance between immunologic rejection and death from uncontrollable infection, since one of the body’s major defensive mechanisms a,%ainst pathogenic microorganisms has been removed.

Fatigue failure in denture base polymers

Abstract: Although well-fitting dentures of adequate thickness seldom exhibit fatigue failure in service, a very small percentage of the millions of denture wearers have well-fiting dentures. Fatigue failure is a very real problem in these dentures, in the well-fitting single upper denture occluding against natural lower teeth, and in all dentures with soft liners. We can make dentures more resistant to fatigue failure by using a few precautions. First, the heat-curing resins are much more resistant to this failure; therefore, use of a heat-curing acrylic resin is indicated. Second, fine-polymer beads increase fatigue strength many times, so a fine-grained polymer should be used. Finally, stress concentrators should be avoided. Most important would be the elimination of sharp surface contours, such as deep notches for low frenum attachments, and prominent rugae patterns. A prominent frenum attachment has little function and is not beneficial to the completely edentulous individual. It is a simple procedure to eliminate the frenum at the time of extraction of the anterior teeth. Any particle acts as a stress concentrator; therefore, acrylic dentures should be fabricated in a relatively dust-free atmosphere such as that used for porcelain work. Fibers and the surface defects that they produce act as stress concentrators, and this should be recognized if a material with fibers is used. Rayon or nylon fibers are used commercially. 20 The use of acrylic fibers should correct this weakness.

Occlusion—the medium of dentistry

Abstract: Any registration of occlusion is dependent upon the musculature. The muscles hold the skeletal system together; nothing else has the capacity for this stabilizing function. Whatever treatment is needed to remove contractures, to place the condyles in normal juxtaposition with the fossae, to promote the normal sensory input into the neuromuscular circuit, and to sustain functional equilibrium is the correct treatment.

Passive control in mandibular rest position

Abstract: Electromyographic techniques were used to show that earlier findings of no activity in elevator muscles during slow mandibular closure are correct, except for movement from rest position to occlusion. Passive factors including tissue elasticity which may influence mandibular posture were discussed.

Maxillary speech prostheses for mandibular surgical defects

Abstract: Speech distortion is one of the debilitating consequences of radical surgery of the tongue, floor of the mouth, and mandible. The major cause of this speech impairment is restricted motion of the tongue and lack of lingual-palatal contact. Since contact between the tongue and the posterior part of the palate is anatomically impossible, a prosthesis is functionally formed to lower the palatal vault. The sounds “k” and “g” require this palatal contact. A series of test words beginning with these consonants was, therefore, used to evaluate possible speech improvement. The results indicated significant improvement in speech intelligibility for those patients with severely restricted tongues with the use of the prosthesis.

Fabrication of a hollow-bulb obturator.

Abstract: A technical description of the fabrication of a hollow-bulb obturator is presented. In an attempt to improve the retentive and stabilizing characteristics of an obturative prosthesis, an outline of the technical construction is proposed which reduces the total weigth of the appliance by processing two separate sections and creating a hollow inner chamber.

Processing a hollow obturator

Abstract: Summary A simple, accurate method for processing a hollow obturator is described. The method is similar to the “two-step” processing technique used in complete dentures. The author wishes to thank Professor W. Krogh-Poulsen, Royal Dental College, Copenhagen for discussions and help in the preparation of this article.

Jaw movements engraved in solid plastic for articulator controls. Part I. Recording apparatus

Abstract: A new apparatus and method for measuring and recording jaw movements was described. All jaw movement information is recorded directly from the patient in the form of engravings in solid plastic. These engravings are related to the hinge axis. Part II of this article will describe a method and apparatus for transferring the information recorded directly from the patient, through a mechanical device, directly into a pair of plastic blocks to form a second set of hinge axis engravings. This pair of transferred recordings will constitute the total information needed to guide the two styluses of the mandibular part of an articulator.

Results of a survey of complete denture procedures taught in American and Canadian dental schools: an update.

Abstract: All the data from this survey have been tabulated and will be available to the cooperating schools for their evaluation and use. It is very obvious from the report that many of the schools are severely handicapped by the common problems of insufficient faculty, little or no auxiliary personnel, limited teaching time, and others. 1 Even though all the schools teach a basic and sound technique, some of the procedures appear to be questionable in view of current research and clinical reports. However, these questionable procedures may be necessary due to the conditions mentioned above. Unfortunately, it is usually more enjoyable and satisfying to criticize than to participate for the purpose of improvement. It is to the self-interest of the practicing dentists to actively support their schools; by their doing so the teaching programs would be improved. Nevertheless, the dental educators have a heavy burden of responsibility. The principles and procedures are usually deeply inculcated and will have a widespread effect on future generations of dentists and patients. Prosthetic dentistry—like any other branch of art and science—is not static, but viable, moving, and, hopefully, improving. Constant re-evaluation of current and future programs should be made by all teachers that are responsible for prosthodontic education.

Prosthetic management of resected edentulous mandibles.

Abstract: Edentulous patients with partially resected mandibles are best treated with uncomplicated appliances. Elaborate mechanical devices are unnecessary when fundamental principles of denture construction are followed. The ramp provided on the maxillary denture serves as a training device for returning the mandible to a functional position. Patients adjust well to these appliances. Through determination and practice, they learn adequate control of mandibular movements. Mastication generally is possible after a short period of accommodation.

Analysis of pressures produced during maxillary edentulous impression procedures

Abstract: A method for measuring pressures produced during edentulous impression procedures has been described. An oral analogue was constructed, and an electric motor was used to carry loaded impression trays to place to minimize variables. Impressions of the analogue were then made by dentists in a clinical manner to establish the validity of the laboratory results. The influence of several impression materials and tray modifications upon these pressures was determined.

Hypersensitivity to acrylic resin.

Abstract: A report of a patient with an untoward reaction associated with exposure to acrylic resins has been presented. Exposure to the material resulted in exacerbation of respiratory symptoms and elimination of the prosthesis was followed by relief. The findings suggest that hypersensitivity to acrylic resin can occur as asthma.

Relative magnitudes of stress on abutment teeth with different retainers.

Abstract: A technique for measuring the relative displacement and stress magnitudes of abutments with four different retainers was described. Tests were conducted with forces applied in four directions.

Accurate interocclusal records.

Abstract: High-quality wax is a useful and versatile material for registering interocclusal records. A carefully observed procedure was described for obtaining accurate results. Zinc oxide and eugenol pastes and plaster are materials that are used for making interocclusal records, but they are not as versatile as wax. Certain situations negate their use. Because of its versatility in handling and because of exhaustive research to produce the ideal product, acrylic resin may become the material of choice for making interocclusal records. At present, its use is limited.

Tooth-supported complete dentures: Description and clinical evaluation of a simplified technique

Abstract: I t has been estimated1 that twenty million Americans are totally edentulous and ten million more are edentulous in one arch. Nearly two thirds of all Americans over the age of 75 years are edentulous. In one study* of the reasons for removal of teeth in an oral surgery practice among middle-income families, 20 per cent were clinically sound teeth but removed for “prosthetic” reasons. These statistics indicate a need for increased efforts in preventive dentistry by all members of the dental profession in order to significantly reduce the number of persons who become edentulous. Patients with many teeth that are hopeless are often candidates for complete dentures. They may, however, have 1, 2, or 3 retainable teeth. Frequently, these few teeth are removed because they are considered inadequate to support partial dentures, and complete dentures are constructed. However, such patients can benefit from tooth-supported complete dentures.

Soft lining materials: Some relevant properties and their determination

Abstract: The softness and elastic recovery of seven soft lining materials have been determined by means of compression and indentation tests. The surface appearance of each material has been noted after storage in a 37 ° C. water bath for six months.

Telescope crown retainers for removable partial dentures.

Abstract: Telescope crowns are used to retain partial dentures They provide the best possible force distribution to the abutment teeth These partial dentures have excellent retentive qualities due to the frictional fit of the crown and sleeve coping and the supplemental retention gained by the plunger spring and the bar clip The telescope crowns have a favorable relationship to the gingival tissues The esthetic result is better than that of clasp partial dentures