Denture Prosthodontics Research Articles

Aligning Clinical Assessment with Course Elements in Prosthodontic Dentistry: A South African Case

Clinical tests were introduced as an additional clinical assessment tool in the prosthodontics curriculum of the fourth-year undergraduate dentistry program at one South African university. This study compared the relationship between the students' performance in the clinical tests and daily clinical grades on the one hand with their theoretical performance on the other. It also explored the perceptions of the academic staff on the validity of clinical tests as an assessment tool. The analysis of the students' test results showed insignificant relationships between their clinical daily grades and their grades for assessing theory. However, clinical assessment via tests is well accepted by the course staff, and they perceived them to be more reliable than daily clinical grades as assessment methods. The findings of the study support other studies that concluded that the daily grades of dental students poorly correlate with their competency exams module. The findings also relate well to the lecturers' views that clinical tests were more reliable as a clinical assessment tool than the students' daily clinical grade.

Live Broadcast Lectures on Complete Denture Prosthodontics at Tokyo Medical and Dental University: Comparison of Two Years

A live broadcasting system was developed as part of dental education with Information and Communication Technology (ICT) at Tokyo Medical and Dental University. The purpose of this study was to utilize this system in complete denture prosthodontics, especially for the procedure of making a definitive impression with custom tray border molding in edentulous patients, and to evaluate its effectiveness. Live broadcast lectures on complete denture prosthodontics were given to fourth-year students in 2009 (fifty-nine students) and in 2010 (sixty-five students). To evaluate this lecture, a questionnaire was distributed to the students and faculty members after the lecture. Almost all the students and faculty members rated the lecture as good. Students commented that the lecture was "intelligible," "inspiring," "improved understanding," "good because they could ask questions in real time," "helped to know the actual time," "good for all the students to see the same case," and "close to real experience and induced a sense of tension." The results of this study suggested that a live broadcast lecture would help students experience the real clinical situation and aid in teaching complete denture prosthodontics.

Theories of Impression Making and their Rationale in Complete Denture Prosthodontics

Theory means observation based on principles and concept is the application of these theories. Impression forms an important virtue for the success of complete denture treatment and hence the concepts of impression should be properly understood. The importance of the in-depth study of history of impression making for complete dentures lies in the thorough understanding of different types of techniques and theories proposed from time to time.

The effect of joint surface contours and glass fiber reinforcement on the transverse strength of repaired acrylic resin: An in vitro study

Denture fracture is an unresolved problem in complete denture prosthodontics. However, the repaired denture often experiences a refracture at the repaired site due to poor transverse strength. Hence, this study was conducted to evaluate the effect of joint surface contours and glass fiber reinforcement on the transverse strength of repaired acrylic resins. A total of 135 specimens of heat polymerized polymethyl methacrylate resin of dimensions 64 × 10 × 2.5 mm were fabricated. Fifteen intact specimens served as the control and 120 test specimens were divided into four groups (30 specimens each), depending upon the joint surface contour (butt, bevel, rabbet and round), with two subgroups based on type of the repair. Half of the specimens were repaired with plain repair resin and the other half with glass fibers reinforced repair resin. Transverse strength of the specimens was determined using three-point bending test. The results were analyzed using one-way ANOVA and Tukey post-hoc test (α= 0.05). Transverse strength values for all repaired groups were significantly lower than those for the control group (P < 0.001) (88.77 MPa), with exception of round surface design repaired with glass fiber reinforced repair resin (89.92 MPa) which was significantly superior to the other joint surface contours (P < 0.001). Glass fiber reinforced resin significantly improved the repaired denture base resins as compared to the plain repair resin (P < 0.001). Specimens repaired with glass fiber reinforced resin and round surface design exhibited highest transverse strength; hence, it can be advocated for repair of denture base resins.

Centric relation definition: a historical and contemporary prosthodontic perspective.

Centric relation (CR) is a core topic of dentistry in general and prosthodontics in particular. The term CR has become thoroughly confusing because of many conflicting definitions. Unfortunately definition of CR changed repeatedly over past ten decades. All the existing definitions in the dental literature, for the past 81years, are segregated into definitions from 1929 to 1970, 1970-1980, and 1980-2010 and are critically analyzed. Both PubMed (key words: centric relation/centric jaw relation) and hand searches were employed, from citation in other publications, to identify relevant articles in English language peer reviewed PubMed journals from 1956 to 2010; although the review is from 1929. Numerous definitions for CR have been given, however, no consensus exists and the definition given by a current glossary of prosthodontic terms is confusing. It relates CR to many clinically invisible parts and cannot guide a dental surgeon to record the CR following its description. The purpose of this article is not only to review all the definitions critically but to propose a self explanatory definition to minimize the confusion in the minds of dental practitioners and students for better understanding of the concept of CR. Centric relation is clinically significant since it is the only clinically repeatable jaw relation and the logical position to fabricate prosthesis.

A blended learning approach to teaching pre‐clinical complete denture prosthodontics

The current study tested the hypothesis that a blended learning curriculum would develop competency in both pre-clinical laboratory and didactic learning with less direct supervision than in a traditional curriculum, and be positively accepted by both the students and the faculty. With the ability to efficiently deliver course material electronically came the ability to blend the traditional delivery of course material with an asynchronous approach involving online lecture presentations and online laboratory demonstrations. The class was divided into two groups with bench space available to accommodate self-paced learning. All audio-visual and written support materials for both didactic and laboratory procedures were provided to the students at the beginning of the semester on a DVD. These materials included online access through the Blackboard Learning System™. Students' performance and satisfaction in the course as well as the supporting faculty response to the course were very favourable to the new blended curriculum. Making use of the technologically advanced environment, the blended curriculum fostered student-focused learning to develop the didactic and laboratory skills necessary for competency in a pre-clinical setting.

Concepts of Arrangement of Artifical Teeth, Selective Grinding and Balanced Occlusion in Complete Denture Prosthodontics

AbstractProsthodontic rehabilitation aims at restoring the patient to a state of normal function, health and optimum esthetics.Numerous factors come together during various phases of complete denture construction. One such factor, the position of artificial teeth, is dependent to a large extent on the state, morphology and position of the denture area existing in the patient's mouth.Artificial teeth must be placed in a position which will be esthetically acceptable to the patient and the clinician, functionally sound and in harmony with the other structures of the masticatory system.Factors governing artificial tooth position include maxillo-mandibular relationships, changes in the residual ridge, dislodging forces, presence of para-functional activity and the esthetic requirements of the patient.While the importance of occlusion in ensuring success of dental therapy cannot be undersated, that seems to be the only point of agreement between authors on this topic. Over the years numerous concepts of occlusion have been proposed which may be indicated and contraindicated based on their benefits and limitations in restoring an edentulous patient. This article explores concepts related to occlusion and esthetics in provision of a complete denture prosthesis.

Three-dimensional dental model constructed from an average dental form

The purposes of this study were (1) to discover a simple method for computing an average dental form, (2) to evaluate the validity of the new computing method, and (3) to build an average digital dental model based on the resulting average dental form. Dental casts of 51 adults were scanned, and 3-dimensional virtual models were reconstructed by using specialized software. Fifty-two anatomic landmarks were plotted on each model to obtain a configuration representing that model. The averaging method was a simplified approach of the generalized partial Procrustes analysis (GPPA); called multiple partial Procrustes analysis (MPPA), it was used to superimpose the 51 sample configurations. For the evaluation method, the GPPA was performed to estimate the population mean form. This mean form was compared with the average forms obtained from the proposed method by using the Procrustes distance as the measure of difference. Construction of the average dental model was based on an average form obtained from the proposed method, and a 3-dimensional dental mesh model was reconstructed. The average forms from the proposed method showed no significant differences compared with the one from the GPPA. The Procrustes distances were about 0.01 mm, which can safely be considered insignificant. The proposed averaging method, which is simpler than the traditional GPPA approach, was found to be feasible for computing average dental forms. The average dental model constructed in this study might serve as a guide for treatment planning in orthodontic and prosthodontic dentistry.

The impact of Er,Cr:YSGG laser on the shear strength of the bond between dentin and ceramic is dependent on the adhesive material

The bond joint between dentin and ceramic is a critical determinant in prosthodontic dentistry. The laser is an alternative to the diamond bur for preparing tooth cavities. However, the impact of lasers on the bond between the laser-irradiated dentin and the ceramic remains a matter of controversy. We determined the shear strength of bonds between ceramic blocks and human dentin discs prepared with either an Er,Cr:YSGG laser or a diamond bur. A total of 180 dentin discs were randomly assigned to four groups. Three groups of discs were prepared with the Er,Cr:YSGG laser irradiation (2 W, 30 Hz, 50% H(2)O, 70% air) and the fourth group was prepared with a diamond bur. In one of the laser groups the discs surfaces were also treated with phosphoric acid and in another with phosphoric acid and mechanical smoothing using a dental excavator. The ceramic blocks were bonded to the dentin discs with Syntac adhesive (together with Variolink II curing system), ExciTE adhesive (together with Variolink II curing system) or RelyX self-adhesive cement. The shear strength of the bond between ceramic and dentin was significantly higher following dentin surface treatment with the laser alone than following treatment with the diamond bur and Variolink II/Syntac (p = 0.021) but not significantly higher than following treatment with the diamond bur and Variolink II/ExciTE (p = 0.138) or RelyX (p = 0.150). A significant difference was not observed when the laser-treated dentin was conditioned with phosphoric acid and mechanical smoothing. These findings demonstrate that the bond between dentin and ceramic may be stronger after laser irradiation; however, the selection of the adhesive material is an additional factor that affects the bond strength.

Cast Removable Partial Denture Rubric

Abstract This resource is a rubric designed for a preclinical removable partial denture prosthodontics course that consists of weekly lectures followed by laboratory sessions. The rubric consists o...

A Clinically Oriented Complete Denture Program for Second‐Year Dental Students

The traditional preclinical complete denture prosthodontic curriculum relies predominantly on the laboratory (e.g., bench-type) component of the complete denture fabrication process. In most cases, this involves a passive model of student knowledge acquisition utilizing lectures and low-fidelity laboratory exercises. A recently implemented program in the College of Dentistry at the University of Illinois at Chicago challenges this educational paradigm by introducing an active learning environment for second-year students based on significant clinical exposure with patients. The result is a major shift of emphasis, first, from a purely technical/laboratory aspect of the discipline to patient-centered education and, second, from mastering individual phases of denture fabrication to understanding the entire process of edentulous patient care. To compare student outcomes in the new program with those in the traditional program, their performance overall and in three components of the final examination for each program were statistically compared. The results of the one-way ANOVA analysis show statistically significant improvement in the students' total score in the new program, including their performance on the written, practical, and OSCE portions of the final examination. This article describes the rationale, logistics, challenges, and advantages of the new educational model of the complete denture prosthodontics curriculum.

Occlusal plane orientation: A statistical and clinical analysis in different clinical situations

Purpose: Orientation of the occlusal plane is important in a number of clinical situations. Using the reported soft and hard tissue landmarks is difficult and requires experience, as the landmarks are located on the face or by use of a cephalometric radiograph. Improper use of these landmarks may compromise the functional and esthetic result of prosthetic restorations. This study evaluated the reliability of the hamular notch/incisive papilla plane (HIP) in establishing the occlusal plane. Materials and Methods: Ninety healthy, Indian adults (60 dentate, 30 edentulous) participated in this study. The occlusal plane of the subjects was compared with their HIPs. In dentate subjects, the maxillary stone cast was mounted on the Wills surveyor with HIP, which was made parallel to the horizontal plane using the tripoding method. The vertical distance between the occlusal plane and floor of the surveyor was measured at four points. When the measured values were equal, the two planes were confirmed to be parallel for that situation. In turn, this relation confirmed the parallelism between the occlusal plane and HIP. In the edentulous subjects, the occlusal plane, established clinically using the ala tragal line, was compared with the HIP radiographically using lateral cephalograms. Paired t-test was used to test the equality of the mean differences at a 0.05 significance level. Results: The mean differences from the right canine were: 0.055 cm at the left canine, 0.05 cm at the right molar, and 0.065 cm at the left molar in dentate subjects and 0.001 cm between the incisive papilla and hamular notch in edentulous subjects. The HIP appeared parallel to the occlusal plane as the paired t-test showed no statistically significant difference (p > 0.05). Conclusion: In the population tested, the HIP was parallel to the occlusal plane. Therefore, this may be a viable reference in complete denture prosthodontics.

Effect of Dental Students as Instructors on Preclinical Performance in Prosthodontics

Dental schools continue to have difficulty recruiting and retaining faculty. One approach to augment student learning would be to train and utilize senior dental students as instructors in preclinical courses. This study was undertaken to evaluate the effect of using senior dental students as instructors on the performance of second-year students in two preclinical prosthodontic courses. In the spring term of 2007, four senior dental students and four or five full-time faculty were assigned as instructors for the fixed prosthodontics and complete denture prosthodontics preclinical courses. Each course has previously been conducted with a total of seven to nine faculty instructors. The performance of two groups of second-year students on preclinical projects was compared based upon their source of instruction for the project. The scores for the two groups were compared using the Wilcoxon rank sum tests and the corresponding 95 percent confidence intervals for the median difference in scores for the two instructor types. This study found no significant difference in performance between sophomore students instructed by full-time faculty or those instructed by senior dental students in either the fixed or removable prosthodontics preclinical courses (p>.05). The use of senior dental students as instructors in the preclinical prosthodontics courses may be one option to partially address the shortage of full-time dental faculty.

Occlusal Plane Orientation: A Statistical and Clinical Analysis in Different Clinical Situations

Orientation of the occlusal plane is important in a number of clinical situations. Using the reported soft and hard tissue landmarks is difficult and requires experience, as the landmarks are located on the face or by use of a cephalometric radiograph. Improper use of these landmarks may compromise the functional and esthetic result of prosthetic restorations. This study evaluated the reliability of the hamular notch/incisive papilla plane (HIP) in establishing the occlusal plane. Ninety healthy, Indian adults (60 dentate, 30 edentulous) participated in this study. The occlusal plane of the subjects was compared with their HIPs. In dentate subjects, the maxillary stone cast was mounted on the Wills surveyor with HIP, which was made parallel to the horizontal plane using the tripoding method. The vertical distance between the occlusal plane and floor of the surveyor was measured at four points. When the measured values were equal, the two planes were confirmed to be parallel for that situation. In turn, this relation confirmed the parallelism between the occlusal plane and HIP. In the edentulous subjects, the occlusal plane, established clinically using the ala tragal line, was compared with the HIP radiographically using lateral cephalograms. Paired t-test was used to test the equality of the mean differences at a 0.05 significance level. The mean differences from the right canine were: 0.055 cm at the left canine, 0.05 cm at the right molar, and 0.065 cm at the left molar in dentate subjects and 0.001 cm between the incisive papilla and hamular notch in edentulous subjects. The HIP appeared parallel to the occlusal plane as the paired t-test showed no statistically significant difference (p > 0.05). In the population tested, the HIP was parallel to the occlusal plane. Therefore, this may be a viable reference in complete denture prosthodontics.

Using the Pinledge as a Conservative Retainer: A Clinical Report

Prior to the invention of the metal ceramic crown, the pinledge retainer served prosthodontic dentistry for many years. The metal ceramic retainer has been the standard of choice for the majority of fixed partial dentures (FPDs) for nearly 40 years. Recent advances with acid-etched, resin-bonded metal retainers and most recently all-ceramic retainers may have led many to believe that the pinledge retainer is an outdated treatment modality. This clinical report provides examples of several types of pinledge retainers used to restore missing teeth or to splint teeth. These patient examples will also demonstrate that the pinledge retainer can provide excellent esthetics for today's appearance-conscious patients.

Current Status of Prosthodontic Education in Japan

The purpose of this study was to clarify the curricular structure, techniques, and materials used in predoctoral prosthodontic programs of Japanese dental schools. A survey of dental schools was conducted by the education committee of the Japan Prosthodontic Society in 2007. The questionnaire was mailed to the chairperson of the prosthodontic departments of 29 dental schools in Japan. Of these, 28 schools returned the completed survey, resulting in a response rate of 96.6%. Results from this survey show that a large majority of schools are using a similar curricular structure in pre-clinical clerkship programs; for instance, the mean number of laboratory hours is approximately twice as long as that of lecture hours. Total hours spent on fixed prosthodontics was the longest, followed by removable partial denture prosthodontics, and then complete denture prosthodontics. The clinical clerkship programs varied considerably from school to school, and in some schools, the opportunities for dental students are very limited. Conclusion: Predoctoral clinical prosthodontic programs vary from school to school, yet a large percentage of schools agree on many topics.

補綴治療に関するガイドライン策定に向けて

In recent years "practice guidelines" based on EBM techniques have even been attracting attention at a societal level, and guidelines modeled after the procedure for preparing practice guideline (described at http://www.niph.go.jp/glgl-4.3rev.htm) have begun to be drafted and made public. With the aim of ensuring the quality and presenting the basic concepts of prosthodontic therapy, the Japan Prosthodontic Society, which bears a great obligation and responsibility toward society and the Japanese public, has decided to undertake the formulation of guidelines related to prosthodontic therapy, and decided to first undertake the formulation of "Practice guideline for denture relining and rebasing", and to prepare a guideline model. We tried to prepare the guidelines according to the "Procedure for preparing practice guidelines", but because of the scientific uniqueness of prosthodontic treatment and dentistry, research to elucidate the basis of treatment has been insufficient, and we ultimately reconfirmed the current state of affairs in which it is difficult to perform. We therefore prepared the guidelines based on the limited evidence obtained in a search of the scientific literature and on the consensus of experts. The Japan Prosthodontic Society has investigated and prepared a Society guideline "model" to the extent possible at the present time, and it has prepared "Guidelines for adhesion bridge" and "Practice guidelines for denture prosthodontics" based on it. Nevertheless, the fact of the matter is that we are faced with numerous problems, and we think that in the future new bases and clinical knowledge will be accumulated by promoting scientific clinical research, and that the guidelines should be revised regularly based on them.

Evaluation of Dental Students as Instructors in Preclinical Prosthodontics and Occlusion Courses

While facing a shortage of faculty members, dental schools need to be innovative in their educational methodologies. One approach to augment student learning would be to mentor dental students as participating faculty in current courses. A study was undertaken to evaluate dental students as instructors in preclinical prosthodontics and occlusion courses. In spring term 2003, three senior dental students (4DN) and four full-time faculty were assigned as faculty for each of two preclinical courses: fixed prosthodontics and complete denture prosthodontics. In the summer term 2003, two junior dental students (3DN) and five full-time faculty were assigned to teach in the occlusion preclinical course. Each course had previously been conducted with a total of seven full-time faculty. Three types of outcome assessment were accomplished: (1) evaluation by the 2DN students of full-time faculty and student instructors at the end of the course using a standardized university scale of 1 (poor) to 5 (excellent); (2) a survey of student instructors about their experience; and (3) a course debriefing with selected 2DN students. The overall mean instructor-quality score assigned to the student instructors, 4.5 (SD, 0.7), was slightly higher than that of faculty instructors, 4.2 (SD, 0.9). Student instructors were rated higher than or equal to full-time faculty based on the mean response scores for all ten evaluation questions. The greatest difference between faculty and student ratings was in the category of "respect and concern for the students" in all courses. In addition, information gathered from eight student instructors indicated that the experience was a very positive one overall with an increased interest in an academic career noted. Comments from the 2DN students in the debriefing sessions were positive about having student instructors. This study demonstrated that from the perspective of second year dental students, senior and junior dental students were accepted as preclinical instructors in prosthodontics and occlusion preclinical courses. Additionally, senior and junior students who participated in student teaching had a positive experience. The use of dental students as preclinical faculty in prosthodontics and occlusion appears to be a viable approach for mentoring students in careers in academics, providing student instructors with higher learning experiences, and supplementing the efforts of full-time faculty.

The future for removable prosthodontics in the UK – a personal opinion

In allowing Clinical Dental Technicians (CDTs) to practise complete denture prosthodontics independently the General Dental Council (GDC) has set a dangerous precedent that could threaten the future integrity of the 'dental team'. In bemoaning the decline in standards for undergraduate teaching of removable prosthodontics the academic specialists, and the BSSPD, only have themselves to blame. It can only be hoped that, once established, Clinical Dental Technicians will raise the woefully low standard of removable prosthodontics in the UK.

Biometric relationship between intercanthal dimension and the widths of maxillary anterior teeth

Problem: Selection of appropriately sized maxillary anterior teeth is one of the difficult aspects of esthetics in complete denture prosthodontics. Many attempts have been made to establish methods for estimating the combined width of maxillary anterior teeth and central incisors using anatomical landmarks, but depending on a single method for this purpose is not advisable in such a crucial esthetic stage. This study attempts to provide a guideline along with other methods for determining this relationship. Purpose: The purpose of the study was to determine whether a relationship exists between the intercanthal dimension and four mesiodistal width combination of the maxillary anterior teeth. Setting and Design: This study has a cross-sectional design. The work was performed in a dental college and hospital. Statistical Analysis Used: Pearson correlation coefficient with paired t test with a confidence interval level of 95%; this is determined on the basis of the sample size. Materials and Methods: Maxillary anterior teeth of 210 patients were examined. The intercanthal distance was measured between the median angels of the palpebral fissure. The mean widths of two central incisors, combined width of the four incisors and combined width of six anterior teeth were intraorally determined at their widest dimensions. Statistical analysis was performed to determine the relationship between the intercanthal distance and the four measurements of maxillary anterior teeth. Results: After the statistical analysis, it was found that biometric ratios of 1: 0.271 and 1: 1.428 could be used to estimate the central incisor width and the combined widths of the six anterior teeth, respectively. Conclusion: Within the limitation of this study, the intercanthal distance can be used as a preliminary method for determining the width of the maxillary anterior teeth during the initial selection of the teeth for an edentulous patient.