Education

Application of Problem Based Learning to Clinical Dental Education

Charles F. Shuler, DMD, PhD

Copyright 2002 Journal of the California Dental Association.

About the Author:

Charles F. Shuler, DMD, PhD, is a professor and director of the Center for Craniofacial Molecular Biology at the University of Southern California School of Dentistry. He is also director of the graduate program in craniofacial biology at USC.

Problem-based learning provides a mechanism for learning in a manner that most closely simulates the future practice environment. PBL was initiated in medical education in the 1960s, and two-thirds of U.S. medical schools use PBL in their programs. The University of Southern California School of Dentistry has moved to the PBL model to give its dental students the knowledge base required for the accreditation standards and to prepare them to be beginning general practitioners. This article explains how USC uses PBL in its dental curriculum.

Problem-based learning requires three specific components for successful use of the pedagogy: small student groups, problems to evaluate, and student-centered analysis of the problem.^1-3 The students investigate a problem following a specific process under the guidance of a faculty facilitator (Figure 1). In the PBL process, the students first identify the facts related to the problem -- those pieces of information known to be true. The facts are what the student group knows. Based on the facts of the problem, the students engage in a stage of critical thinking to determine their ideas about the nature of the problem. The ideas represent what the student group thinks about the case. The group’s ideas can be prioritized from most likely to least likely and then used to establish the areas of research and learning needed to more clearly evaluate their ideas. The learning needs represent what the students need to know. Achieving the learning needs results in the generation of a series of new facts based on the content of the resources applied to the learning that can be used to evaluate the ideas and refine the student group’s thinking about the problem. The learning needs represent new facts available to both the student and the group. Each student masters these learning needs and advances his or her individual knowledge base of the content which is critical to developing those competencies associated with a new graduate dentist. The learning needs are the curricular content of the dental education program and can be predicted by the faculty based on the presentation of the problem. All the problems presented throughout the four years of dental education contribute to the knowledge base required for accreditation and to prepare a student to be a beginning general practitioner.

The development of problem-based learning as a pedagogy in health education is not unique to dental education.⁴ PBL was initiated in medical education in the 1960s, and two-thirds of U.S. medical schools use PBL in their programs. In half of the medical schools using PBL, it is the primary pedagogy; while in the other half it represents the pedagogy of a subset of courses or curricular emphases. In the literature on medical education, it has been shown that the students who were enrolled in medical schools using primarily PBL were more prepared for clinical patient care and performed better in their clinical clerkships. They had learned the material in a context that was similar to the final application, and this was judged critical to knowledge retention and subsequent application. Professor H. Schmidt of the University of Maastricht in the Netherlands has published extensively on the outcomes of students learning in a PBL environment. He has concluded: "The closer the resemblance between the situation in which something is learned and the situation in which it is to be applied, the better the performance and the easier it is in respect of recall and application." The origin of PBL in medical education was based on the manner in which physicians approached the evaluation and treatment of patients.

In patient care, the PBL stage of identifying the facts is equivalent to determining the chief complaint, reviewing the history of present illness, reviewing the past medical history, and completing a physical evaluation. These facts of the clinical presentation of a patient are a critical first step and require the development of a process of evaluation so that all of the important aspects are reviewed. Based on these findings, the health professional develops a set of differential diagnoses, equivalent to the ideas, since these are meant to be inclusive and will become focused when additional data is obtained. Additional tests, radiographs, laboratory findings, and specialty consultations provide new data that is equivalent to the outcomes of the learning needs that students pursue while investigating a PBL problem. In the clinic, the chief complaint is further defined; and ultimately a definitive diagnosis is obtained that permits the initiation of a course of therapy. The development of a comprehensive approach to patient diagnosis is critical, and the PBL pedagogy has been shown to provide students with a process to comprehensively evaluate a problem.

Medicine has used an approach very similar to the PBL pedagogy in the education of residents. The use of "rounds" to involve all physicians on the service with the care delivered to all patients is based on the patient "problem." Each patient is reviewed and residents learn their clinical skills based on the care of these patients. Those areas that are not well-understood require additional tests, consultations, and review of the literature, equivalent to the process used in PBL. This is true of both medical and surgical specialties, and the technical aspects of surgery are reviewed with the resident groups during rounds and later applied by the individual in either the operating room or clinic. The group of residents who participate in the rounds support the cognitive learning of each individual with respect to the indications for and applications of a specific procedure. The group further provides a valuable resource to review outcomes, suggest alternative approaches in the future, and define experiences essential to advancing the necessary technical expertise.

Concerns have been raised that using PBL as a primary pedagogy in dental education may not provide the learning environment necessary to master the clinical skills required to demonstrate the competencies necessary prior to dental school graduation. The University of Southern California School of Dentistry has embarked on a strategy to use the student-centered, inquiry-based PBL pedagogy for both the basic and clinical sciences. In the basic sciences, PBL has been shown to be associated with improved performance on standardized tests.⁵ The use of PBL to support clinical learning is presented in this paper through the example of a case used to help students master the fundamentals of cariology and the procedures necessary to restore tooth surfaces to their appropriate form and function following carious destruction.

A Problem Used to Learn Cariology and Restorative Dentistry

The "problem" is the fundamental unit for the activities of the PBL student-learning groups. Two problems are presented here that are learned in sequence, the first to introduce the pathogenesis of dental caries and the second to introduce the restorative procedures required to treat the patient’s dental caries. Each problem is pursued in a series of facilitated sessions with a faculty mentor. At the first session, the students meet their problem. In the present example, the patient with the problem is named Ivan Joyce Jr. (Figure 2). The students also receive critical documentation for the patient using the identical format they will use in the future in the USCSD dental clinic, including radiographs of the chief complaint region (Figure 3). Based on the information provided, the investigation of the problem will begin and range widely through the microbiology, pathology, histology, radiology, community, nutrition, behavior, and epidemiology. The problem will be pursued from "the molecule to the community." The students rapidly become engaged in their learning because the situation is easily visualized as a future patient care setting in their career.

The students continue to investigate the problem as additional facts become available and refine the nature of their investigations (Figures 4, 5 and 6). This investigation includes reviewing caries charting from exploring in the clinic, reviewing the appearance of Ivan’s mother’s teeth, and careful evaluation of a full-mouth set of radiographs. Ultimately, the student is charged with explaining to the simulated patient exactly what is wrong, what pathology requires treatment, and the etiology of the dental disease (Figure 7). The patient problem served as the "vehicle for learning"; however, the content mastered by the student is identical to the content in traditional lecture-based courses. The primary difference is that there is an absence of an artificial separation of content areas based on different course titles. Instead, the material is all mastered in a context highly relevant to a future practice experience, which, again, is the type of learning methodology that has been shown to be highly effective in generating student engagement and retention of knowledge.⁶ The students accomplish these learning outcomes in a two-week period meeting Monday, Wednesday, and Friday in facilitated sessions that push the content and advance the student understanding (Table 1). The major learning outcomes of the case of Ivan Joyce, Jr., are listed in Table 2. The intended goal of this case is to introduce the fundamentals of dental caries, fluoride, nutrition, and patient diagnosis. At the conclusion of the problem, each student now has a "practice" that includes a patient with dental disease that requires specific technical therapies. The practice includes a complete record with the data required to generate the appropriate diagnoses and develop a comprehensive treatment plan.

The students are not finished with Ivan Joyce, Jr., after the initial two-week PBL experience. Mr. Joyce remains a patient in the "practice," and he returns a few weeks later in the curriculum (Figure 8). His return models the experience that students will have in practice linking the diagnostic phase with the development of a treatment plan and the initiation of therapy. In the patient’s return to the practice, he has decided that he wants to have the teeth treated to remove the disease and return them to optimal form and function. The second experience evaluating Mr. Joyce results in an in-depth analysis of the methods to restore teeth with Class I, II and V dental caries. In the problem, the patient is provided with the necessary information to make an informed consent regarding treatment and selects amalgam restorations. In this way, the problem leads the students to the critical learning needs related to the fundamental direct intracoronal restorations. In their second experience, the students master the basic information related to preparation design, the criteria to evaluate preparations, the dental materials required, and the appropriate instruments to complete the tasks (Table 3). At the completion of the problem "Ivan Joyce, Jr., Returns," the students have mastered the fundamental principles and basic content related to direct intracoronal restorative dentistry. What remains is the application phase to develop the psychomotor skills necessary to complete the restorative procedures. The treatment plan developed in the problem serves as the vehicle to move the PBL problem from the small-group sessions to the simulator laboratory.

Problem-Based Learning in the Simulator Laboratory

Treating a simulated patient represents the educational ideal, learning in a context relevant to the eventual application. Ivan Joyce, Jr., is the patient who will be "treated" in the simulator laboratory in weeks three to 16 of Trimester 3 as indicated in Table 4. The simulator laboratory provides a venue for the students to treat the "patients" in their practice and apply the restorative principles that have been learned in the problem setting. The students use the simulator laboratory with the approach they will ultimately use in all the clinical venues of the School of Dentistry. This includes adherence to infection control procedures and clinical record-keeping of the course of therapy of the patient. The treatment plan for the simulated patient is followed and dictates the procedures that will be completed on the typodont at each preclinical session. In the simulator laboratory, the only real differences from the ultimate setting in dental school clinics is the absence of saliva, the lack of anesthesia, and the absence of a patient behavior component. The treatment plan for the simulated patient has been developed by the faculty so that the progression of learning the clinical skills is quite similar to a traditional preclinical laboratory. In that manner, the learning can be structured however the students are engaged in the process since they are beginning to deal with the simulated patient in exactly the same manner as in their future student and private practices.

Another element key to PBL in the preclinical and clinical areas is the adoption of the learning strategies used in medical residencies. Each preclinical experience is initiated with a pre-session during which a group of students meet with their clinical mentor and discuss the procedures that will be applied to the simulated patient during the session (Table 4). The treatment plan is used as a guide; and the preparation design, materials, and clinical considerations are reviewed. This models the behavior that students will need to be prepared to deliver care to their patients and to understand the requirements for each clinical session. Following the pre-session discussion, each student individually treats the simulated patient following the protocols that were discussed. During this individual application phase, faculty experts continuously monitor student progress and provide assistance to achieve the calibrated outcomes that were intended. Several identical procedures can be completed on the simulated patients and can help the student to progressively build his or her clinical expertise. The progress of treating the simulated patient is recorded in the progress notes section of the preclinical record of Ivan Joyce, Jr., to continue modeling the types of activities that are required in the clinic and build the necessary expertise in patient record-keeping. At the close of each application phase, the student group reconvenes for a post-session to discuss the outcomes of the treatment of their simulated patient (Table 4). In these sessions, students identify areas of difficulty and areas that require both additional practice and additional learning. The new learning topics become subjects for discussion at future pre-sessions, and in this way the entire group of students benefits from the clinical experiences of all their peers. The treatment of the simulated patient follows the highest levels of quality and builds an approach to patient care that is readily transferable to the clinical setting.

Summary

The procedures and techniques used in the simulator laboratory and clinic have not changed from those traditionally taught at the USC School of Dentistry. Rather, the manner in which the students discover the learning has changed to an origination from the study of a patient-based problem that simulates a future clinical experience. The application of the knowledge to develop the psychomotor skills is facilitated by discussion sections in which students learn from all the experiences of their peers, in the same manner used by physicians in residency. The active participation of faculty experts to assist students in the development of their clinical skills is also facilitated by the discussion during which faculty can learn the strengths and weaknesses of their students. The creation of an atmosphere of supportive discussions and constructive critique begins to model the professional behaviors so critical for the success of the new graduate. Problem-based learning provides a mechanism for learning in a manner that most closely simulates the future practice environment and encourages the students to adopt professional behaviors and approaches to patient care that model the very best in the profession.⁷

Acknowledgments

Many faculty colleagues at the USC Center for Craniofacial Molecular Biology and the USC School of Dentistry have been instrumental in the development of the Problem Based Learning Program at the University of Southern California. I want to thank all of them for their many contributions to the development of a program that has attracted worldwide attention for a creative new approach to dental education.

References

1. Fincham AG, et al, Problem-based learning at the University of Southern California School of Dentistry. J Dent Ed 61:417-25, 1997.

2. Fincham AG and Shuler CF, The changing face of dental education: The impact of PBL. J Dent Ed 65:406-21, 2001

3. Shuler CF, Keeping the curriculum current with research and problem-based learning. J Am Coll Dent 68(3):20-4, 2001.

4. Abrahamson S, Myths and shibboleths in medical education, Teach Learn Med 1:4-9, 1989.

5. Shuler CF and Fincham AG, Comparative achievement on National Dental Board Examination Part I between dental students in problem-based learning and traditional educational track. J Dent Ed 62:666-70, 1998.

6. Bransford JD, Brown AL, and Cocking RR, eds, Committee on Developments in the Science of Learning, National Research Council, How People Learn: Brain, Mind, Experience, and School. National Academy Press, Washington DC, 1999.

7. Field MJ, ed, Committee on the Future of Dental Education, Institute of Medicine, Dental Education at the Crossroads: Challenges and Change. National Academy Press, Washington DC, 1995.

To request a printed copy of this article, please contact/Charles F. Shuler, DMD, PhD, USC School of Dentistry, 925 W. 34th St., Los Angeles, CA 90089-0641 or shuler@hsc.usc.edu.

Figure 1. The Process of Problem-Based Learning

Figure 2. Ivan Joyce, Jr., Part I / Figure 3. Radiographs for Ivan Joyce, Jr.

Ivan Joyce is a 22-year-old real estate salesman from San Marino who has completed all the required past medical history and personal information forms. He arrives in the office as a new patient with complaints of sensitivity of several posterior teeth following exposure to either cold drinks or sweets. There was no history of any sensitivity to either hot food or drink. On further questioning, the sensitivity seems particularly localized in the region of the mandibular left first molar.

Interestingly, Mr. Joyce reports that he has never previously sought the care of a dentist and that he eats a lot of candy and drinks several Cokes each day. His parents were born and raised in the panhandle region of Texas, where his father was an open-pit metal miner. Neither of his parents ever experienced any decay, although their teeth were mottled in appearance with some stains. Mr. Joyce says that his parents commented that, "it was something in the water back home," that affected their teeth. Ivan was born and raised in Los Angeles and has always been complimented by his parents for his white, straight teeth, which look much better than theirs.

A hard- and soft-tissue head and neck exam was completed and periapical radiographs of teeth 18-21 were completed to help diagnose the chief complaint.

Figure 4. Ivan Joyce Jr. Part II / Figure 5. Chart for Ivan Joyce Jr.

Mr. Joyce was advised of the diagnosis of tooth #19 and the etiology for the cause of his signs and symptoms. He was advised that a comprehensive dental examination and complete mouth radiographs were necessary for a thorough evaluation, diagnosis, and consideration on needed therapy. The radiographs and intraoral caries and periodontal charting were completed during the appointment.

A fascination with the lack of cavities in Mr. Joyce’s parents lead you to encourage them to visit the office for an evaluation of their dental status.

Figure 6. Photo of affected area.

Figure 7 Ivan Joyce Jr. Part IV

Ivan returns to your office for a discussion of your examination findings. You discuss with him the teeth that are affected by dental caries and the status of his periodontal health. During the review of your findings, Ivan becomes rather depressed and blames himself for the incidence of his caries. Mr. Joyce remains confused by the cause of dental caries and how his teeth have been affected. In particular he doesn’t understand the difference between his parents’ experience with dental decay and his own. You present a detailed account of the etiology of dental caries and the pathology that has affected his teeth with emphasis on the different experience of his parents.

Figure 8. Ivan Joyce Jr. Returns Part I

Mr. Joyce returns to your office to discuss the restoration of his teeth that have dental caries. He has had no change in his chief complaint and you review his medical history to compare the findings with those of the initial examination. The intraoral and radiographic findings are presented to the patient. Following your review of the clinical findings, you explain to him the teeth that require restoration and the types of restorations that are required. You discuss with him the various alternative materials and approaches to completing intracoronal dental restorations.

Documentation

Complete dental record, radiographs and typodont models

Table 1. Sequence of Learning Basic Principles and Clinical Application