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R P Desjardins

Publications and source records attributed to R P Desjardins.

At least 19 recordsLinked to original sources
PubMed1996

Endosseous implants in an irradiated tissue bed.

Endosseous implants have been placed at the Mayo Clinic Department of Dental Specialties for over 12 years. On the basis of the clinical success of the osseointegration program, the use of implants has been expanded to include placement into tissue beds that have been exposed to therapeutic radiation. This article details preliminary data regarding implant survival in the previously radiated tissue beds. Presurgical evaluation and surgical technique are described and postprosthetic reconstruction complications are also related. Consideration is given to the relatively small number of patients in this review. It is suggested that the results should be shared among multiple institutions to create a meaningful data bank.

Dental Implantation, Endosseous↗
PubMed1996

Implants for the edentulous patient.

With the introduction of osseointegration, the use of dental implants to support and retain dental prostheses had become predictable and offers the patient and the dentist an alternative treatment option. This article describes the indications for implant prostheses, the factors to be considered in pretreatment patient evaluation, and the basic techniques in using implant prostheses in the mandible and the maxilla.

Bone Transplantation↗
PubMed1992

Fatigue strength of cantilevered metal frameworks for tissue-integrated prostheses.

The design of the metal alloy framework in cantilevered sections of fixed tissue-integrated prostheses, is critical. Several cross-sectional designs have been advocated, including the popular L-shaped beam, which permits the economical use of space for tooth placement. The fatigue strengths of 15 L-shaped cantilevered framework sections of the same metal alloy were tested. The castings were divided into three groups of five according to vertical wall heights of 4, 5, and 6 mm. Fatigue durability of each sample was determined by counting the number of cycles of vertical forces required to induce catastrophic failure. Statistical analysis revealed significant differences between all three groups in the cycles counted at failure (p less than 0.0019). Fatigue strengths improved significantly with increasing vertical wall height of the L-shaped cantilevered frameworks. In addition, beam flexure was shown to be indirectly proportional to fatigue strength. Theoretical beam deflection was calculated and shown to correlate with the actual beam deflection during the testing. Theoretical calculations in static bending specific for a cross-sectional design may aid in the predictability of fatigue strength.

Dental Alloys↗
PubMed1992

Prosthesis design for osseointegrated implants in the edentulous maxilla.

The position of osseointegrated implants in the edentulous maxilla is dictated by available bone and can vary widely among patients. Anatomy limits the amount of bone available for placement of osseointegrated implants. With increasing resorption, the number, length, and position of implants are further compromised. Bone grafts are frequently needed to place implants of adequate length. The variability of implant placement indicates the need for multiple prosthesis designs in the maxilla. Prosthesis design considerations are suggested for patients with minimal, moderate, and severe resorption of the edentulous maxilla.

Alveolar Bone Loss↗
PubMed1991

Extraoral application of osseointegrated implants.

The use of osseointegrated implants to provide support for craniofacial prostheses has provided the clinician with another approach to the treatment of complex craniofacial reconstructive problems. The surgical technique is reviewed and the Mayo Clinic experience is presented.

Adhesives↗
PubMed1988

Tissue-integrated prostheses for edentulous patients with normal and abnormal jaw relationships.

Diagnosis and treatment planning are keys to successful prosthodontic rehabilitation. The increasing interest in the use of the tissue-integrated prosthesis to resolve the problems of edentulous patients indicates caution in the selection of patients for this procedure. Even if patients are identified who could potentially benefit, application of the concept must meet the needs of the patient. The treatment planning phase must include all professionals participating in patient management and must consider the best placement of fixtures to improve patient findings to an optimal degree. Although many patient factors must be considered in treatment planning, this article discussed application of the tissue-integrated prosthesis concept as it relates to jaw relationship. The tissue-integrated prosthesis must not compound or create retention and stability problems found with complete dentures. This article suggests treatment considerations in planning the tissue-integrated prosthesis for normal and abnormal jaw relationships.

Bone Resorption↗
PubMed1986

Maxillofacial prosthetics: demand and responsibility.

Graduates of maxillofacial prosthetic training programs during 1980 through 1984 were surveyed to evaluate the demand for maxillofacial prosthetic services in the United States. The recent change in requirements for advanced education programs in prosthodontics and the increasing numbers of those with additional training in maxillofacial prosthetics suggests that the demand for these services is decreasing. In addition, there appears to be a distinct separation of institutional from private office management of patients. Because of these changes, the concept of maxillofacial prosthetic training and practice as known in the past may change with an increasing role for the hospital-based dentist in the interim management of these patients.

Dental Service, Hospital↗
PubMed1986

Dental implants: tissue-integrated prosthesis utilizing the osseointegration concept.

As an alternative to conventional removable dentures, osseointegrated dental implants can now be used in carefully selected edentulous or partially edentulous patients. The implant consists of a dental prosthesis and an anchorage unit made up of screw-connected components. The implantation procedure is performed in two phases: fixture installation and fixture uncovering and abutment connection. After completion of these surgical procedures, the dental prosthesis is fabricated and inserted. Follow-up examinations are scheduled at 1, 3, and 6 months and then annually thereafter. During a 2-year period at the Mayo Clinic, 358 osseointegrated dental fixtures were implanted in 70 patients. The overall success rate in this consecutive series of patients was 98%, and the associated complications were minimal and easily resolved.

Aged↗
PubMed1986

A new method for fixation of external prostheses.

As more extensive craniofacial resections for recurrent orbital and nasoethmoidal carcinoma are performed, the need for complex external prostheses increases. A new method of stabilization for large prostheses using osseointegrated implants is presented. This is illustrated in a typical patient who underwent a large naso-orbital maxillary resection for recurrent basal cell carcinoma.

Basal Cell Carcinoma↗
PubMed1985

Hydroxyapatite for alveolar ridge augmentation: indications and problems.

The increased use of hydroxyapatite for augmentation of residual alveolar ridges has created some problems in the subsequent fabrication of complete denture prostheses. Although hydroxyapatite appears to be an effective substitute for resorbed alveolar ridges, its use is not indicated for all patients. In addition, the premise that "if a little is good, a lot is better" does not apply. The following conclusions can be drawn. Augmentation should not be considered if vestibular extension will provide acceptable results. Placement of hydroxyapatite should improve the contour and amount of the residual alveolar ridge. Use as little as possible to accomplish the goal. Preprosthetic surgery should permit vertical as well as horizontal extension of the denture. Augmentation should not result in the need to use lining mucosa to support a complete denture. Vestibular extensions are indicated for most augmented alveolar ridges. The relative strength of the strong arch should not be increased in prognathic or retrognathic ridge relationships. Preprosthetic surgery should be a combined surgical-prosthodontic treatment endeavor. If a foundation is created that cannot be used effectively for the support, retention, and stability of an intended prosthesis, little benefit is provided for the patient. Small variations in intended treatment can significantly increase success of the prosthesis (Fig. 13). Unfortunately, the relative ease of hydroxyapatite placement has led to its use in patients who do not require augmentation and augmentation in amounts and regions that are not conducive to improving denture success. A coordinated effort between the surgeon and the prosthodontist will usually result in treatment that provides the best potential foundation for a specific patient.

Alveolar Ridge Augmentation↗
PubMed1982

Clinical evaluation of the wax trial denture.

A complete denture is a mechanical object, much of which is fabricated outside the dental operatory. Its specific fabrication, however, is dictated by clinical facts, as outlined in instructions provided by the dentist. This mechanical object must function in a biologic atmosphere, and every effort must be made to assure a harmonious relationship between the mechanical and the biologic. The wax trial denture stage becomes a critical phase of complete denture care in evaluating this relationship. The wax trial denture should be evaluated relative to trial base stability, vertical dimension, centric and protrusive jaw relationships, tooth selection, the level of the occlusal plane, buccolingual and anteroposterior tooth position, and occlusal articulation. Although all of these factors should be further evaluated at the denture insertion stage as well as at each recall visit, only at the wax trial denture stage can significant changes be easily accomplished. The wax trial denture evaluation should receive adequate consideration in any complete denture technique.

Dental Occlusion, Balanced↗
PubMed1979

Occlusal considerations for the partial mandibulectomy patient.

The occlusal scheme fabricated for a patient with a mandibular defect varies extensively from patient to patient, with some limitations in occlusal efficiency. Some patients may expect little or no occlusal efficiency if the defect is large and if the associated mandibular deviation and the lack of muscle control and excessive. If the continuity of the mandible can be restored by secondary surgical management (Fig. 10, A), most of the problems of the discontinuity defect can be resolved. Whether the teeth in the region of the defect are replaced or not may be dependent on other factors, but the mandible can be treated as a stable entity within itself, and the prosthodontic approach can be similar to that discussed for the continuity defect (Fig. 10, B). The mandibulectomy patient is difficult to manage because the prosthodontist is limited in his ability to provide a reasonable and practical occlusal scheme. However, these patients need the definitive clinical and psychological support of the prosthodontist. Most patients recognize the limitations of their rehabilitation and are appreciative of the prosthodontic therapy that enhances their rehabilitative progress.

Dental Occlusion↗