Bernard Levin

The use of microwave energy for processing acrylic resins

Test strips of five different resins were processed with (1) microwaves by using a kitchen-type microwave oven, and (2) a conventional water bath. The strips were tested for hardness, porosity, and transverse strength. The results showed no significant difference between resin strips cured by either method. Maxillary dentures were waxed on stone casts of an aluminum model in another study. The dentures were processed with the same five resins, half by using microwave energy and the remainder with the water bath. The adaptation of the processed dentures to the aluminum cast was measured with feeler gauges. The results showed no statistically significant differences between dentures cured by either method. These studies demonstrated that the important physical characteristics of microwave-cured resin are approximately the same as resin cured in a conventional water bath. Curing dentures by microwave energy has the advantages of reduced curing time, ease, and cleanliness.

Results of a survey of complete denture procedures taught in American and Canadian dental schools

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.

An overdenture survey: Preliminary report

The preliminary conclusions from this survey are listed: 1. The exceedingly high incidence of periodontal pathology seems to be the major problem in the long-term use of overdentures. 2. The incidence of caries is fairly low, but it remains a potential problem. 3. Subjective evaluations by the patients are favorable. 4. The overdenture technique as described by Lord and Teel seems to be practical and advantageous. 5. Additional research to find the most effective agent for inhibiting caries in overdenture support roots should be initiated. 6. Need exists for more surveys by other schools, institutions, or prosthodontists. 7. The overdenture is a valid alternative to complete denture therapy.

A practical questionnaire for predicting denture success or failure

The need and value to predict success and failure in treatment of denture patients are great. The psychological and emotional factors involved are just as important as if not more important than the oral and systemic findings. The value of a simple questionnaire for the edentulous and immediate denture patients has been presented. The authors believe that all schools should present advanced information on the psychological aspects of dental care.

A reliable reline-rebase technique

A reliable reline-rebase technique is very important to the general dentist. There are many excellent techniques, but this particular one has provided the most consistent results and patient satisfaction. No technique has any value unless a careful treatment plan is followed and technical procedures are performed with skill and concern.

Some observations and opinions on European dentistry

1 was fortunate to have a six-month sabbatical leave in 1973, mainly spent in western Europe. My principal intent was to study prosthodontic education, techniques, and research, but I also took the opportunity to represent the American Prosthodontic Society in their international goodwill program. I visited ten countries and 16 dental schoois and lectured or presented courses for six dentai societies. However. since I spent almost two months at Guy’s Hospital Dental School and tlvo and one half rnonths in all in Sweden, Denmark, and Norway, I shall confine mv comments to these areas where I observed policies and trends that, to me, seem iniportant and relevant to dentistry in the United States. I feel compelled to add that, although my limited stay cannot oualiI’y me as ;I quotable authority in these matters. I did spend enough time and energy to collect information that has reasonable credibility. Hecallsc more than 50 per cent of the people of the United Kingdom are partially or completely edentulous,’ study in complctr and partial dentures is an important part of the dental school curriculum. I should say that this area is taught thoroughly ;1Kd well, judging from my observations in three schools visited in London. nne in Wales, and three in Scotland. At my own school and many others. denture patients are not readily available, but at Guy’s Hospital Dental School and most of thr other schools in the United Kingdom, there was no such problem. In fact, patients had an average \vait of 18 months to two years to obtain new dentures at Guy’s, One major reason is that the National Health Service provides an allowance of about

Patient preference for a mandibular complete denture with a broad or minimal base: A preliminary report

41.00 for dentures, so all patients with the least bit of difficulty (flat ridges or whatever) are referred to dental schools for treatment. I was very interested in the National Health Service, and I tried to discuss it with as many lay people and dentists as possible. My impression is that it is well accepted by the general public, it is not popular \vith the average dentist, and it i

Use of silver alloys to oppose lingual bladed denture teeth

suicidal for a politician to even mention. its elimination.. It has resulted in the provision of basic dental care to those who choose to avail themselves of it, but only

Flange technique: An anatomic and physiologic approach to increased retention, function, comfort, and appearance of dentures

lh b e asic requirements of the properly extended denture base have been documented and published in many standard prosthodontic textbooks. It is generally accepted that well-placed denture borders provide peripheral seal, and thus, greater retention and stability are attained. However, more important is the fact that correct extensions of the denture base result in greater distribution of stress. The forces of mastication then are distributed over the widest supporting area, and the forces on local areas are minimized. This enables the patient to chew a greater variety of foods with more comfort and with less possibility of ridge trauma and bone loss. Nevertheless, due to design or to possible patient demand, many dentures are made with grossly underextended borders. It is a rational assumption that the average denture patient would prefer to have his teeth replaced with the least amount of material. Patients who wear mandibular dentures often object to the retromylohyoid flange, the buccal flange, and the denture base that covers the retromolar pad. These areas never have contact with foreign material and also were never covered if the patient wore a fixed or a tooth-supported removable partial denture. All too often, even the distal-extension partial denture has minimally extended borders as excessive dependence is placed on the remaining teeth for retention and support. The presence of a new denture with correctly extended borders requires the patient to make a gross adjustment in the oral environment. Complaints of difficulties in speech, mastication, swallowing, and other areas are common.

Effects of patient involvement and esthetic preference on denture acceptance

T he lingual bladed tooth (U. S. Shizai, Los Angeles, Caiif.) was originally designed in 1974 and reported in i! 977.‘In 1980 McCartney* expressed concern regarding the rapid wear usually associated with resin teeth and described a technique for fabrication of cast metal occlusal surfaces for mandibular teeth that oppose bladed teeth. Since then extended use of bladed teeth for removable partial dentures in younger and/or more vigorous patients has demonstrated that McCartney was correct, because excessive wear has been observed. Because of these observations we realize that a harder chewing surface is needed for mandibular teeth for patients who would predictably have more rapid wear. The following technique, originally developed for removable partial denture and implant patients, is now used for about 30% of all patients with lingual bladed dmtures. Fig. 1. Tips of bladed teeth are easily identified in wax.