Implant therapy, and the prevalence with which. An Overview of U.S. Predoctoral Dental Implant Programs and Their Directors

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1 Predoctoral Dental Education An Overview of U.S. Predoctoral Dental Implant Programs and Their Directors Christopher A. Barwacz, DDS; Gustavo Avila-Ortiz, DDS, MS, PhD; Veerasathpurush Allareddy, BDS, MBA, MHA, PhD, MMSc; Monelle Tamegnon, BS, MS; Kaitlin Hoogeveen, BS Abstract: The aim of this study was to provide an overview of current predoctoral implant programs in the United States, including curricular characteristics and clinical practices regarding implant therapy education and program directors characteristics. An electronic survey was sent to predoctoral implant program directors of all 64 accredited U.S. dental schools; 52 of the 60 eligible programs responded, for a response rate of 87%. The responding program directors were primarily affiliated with either prosthodontics departments (44%) or restorative dentistry departments (40%). Structurally, 80.8% of the responding schools integrate their implant programs into the third year of the curriculum. Clinical implant therapy exercises reported were simulation exercises without direct patient care (90.4% of responding schools) and direct patient care under supervision (94.2%). The most frequently taught restorative modalities are posterior single-tooth implant crown (96.2%), mandibular implant-retained overdenture (88.5%), and anterior implant-supported single crown (61.5%). A majority (74.5%) of responding programs utilize analog surgical guide planning, while 25.5% reported use of digital guided surgery planning software. All schools in the Northwest and 66.7% in the South Central regions utilize custom abutments as the primary abutment design, while a majority of schools in the North Central (62.5%), Northeast (53.8%), Southwest (66.7%), and Southeast (80%) regions use stock abutments (p=0.02). Regional differences were significant with regard to fixation modality, with all the Northwest programs using screw retention and 90% of Southeast and 87.5% of North Central programs using cement retention (p=0.002). This study demonstrated that while institutions share program director and curricular similarities, clinical practices and modalities vary significantly by region. Dr. Barwacz is Assistant Professor, Craniofacial Clinical Research Center, The University of Iowa College of Dentistry and Dental Clinics; Dr. Avila-Ortiz is Assistant Professor, Department of Periodontics, The University of Iowa College of Dentistry and Dental Clinics; Dr. Allareddy is Associate Professor, Department of Orthodontics, The University of Iowa College of Dentistry and Dental Clinics; Ms. Tamegnon is Graduate Student, Department of Biostatistics, The University of Iowa College of Public Health; and Ms. Hoogeveen is Predoctoral Student Researcher, The University of Iowa College of Dentistry and Dental Clinics. Direct correspondence to Dr. Christopher A. Barwacz, The University of Iowa College of Dentistry and Dental Clinics, Craniofacial Clinical Research Center, W425 Dental Science Building, Iowa City, IA ; ; chris-barwacz@uiowa.edu. Keywords: dental education, dental implants, implantology, prosthodontics, curriculum Submitted for publication 6/13/14; accepted 7/28/14 Implant therapy, and the prevalence with which it is employed in modern dental practice, has progressed significantly since its early adoption; as a result, it has gained widespread acceptance and adoption as a tooth replacement strategy for partial or complete edentulism by both clinicians and patients. 1-3 This maturation can be attributed to the high success rates generally observed in oral implantology, 4-7 the demonstrable improvement of patient quality of life measures as a result of treatment, 8-10 the long-term cost-effectiveness when compared to other prosthetic options, and the relatively low complication rates 15 when compared with other transcortical orthopedic devices. 16,17 To address an increase in patient demand for implant therapy, both European 18 and U.S. academic dental institutions and their representative organizations 19 have recognized the need for increased inclusion of implant therapy at the predoctoral level, where education in singletooth implant and implant overdenture restorative therapies is feasible. 20,21 In the past two decades, an increasing majority of U.S. and European academic institutions have established dedicated predoctoral dental implant programs in an effort to prepare general dentists for the provision of routine dental implant restorative therapy. While dental implant therapy has been conducted for over four decades, its incorporation into predoctoral dental curricula has been markedly conservative when compared with other treatment March 2015 Journal of Dental Education 265

2 modalities and technological advancements. In 1974, 33% of U.S. dental schools reported including implant therapy in their predoctoral curricula; 22 this coverage grew to 84% by At the outset, such an increase in implant education appears substantial, yet recent national evaluations of graduating predoctoral dental students have found significant perceptions of deficiency with regard to students implant education and acquisition of proficient clinical skills upon graduation. The two most commonly cited student perceptions are that there is inadequate time (39% of respondents) in the predoctoral curriculum to master implant concepts and thus they feel a lack of preparedness (43%) with regard to perceived proficiency in providing routine implant therapy. 24,25 While there has been a decline in the percentage of graduating students reporting inadequate time since 2001 (when more than 50% reported this perception 26 ), the percentage reporting a perceived lack of preparedness has remained steady. Such data should not be taken lightly, as it has been demonstrated that graduates who not only have formal didactic implant education (lectures, seminars, case series reviews) but also actively participate in preclinical laboratory 27 and clinical management of implant patients in predoctoral programs overwhelmingly restore greater numbers of implants, refer more patients to surgical specialists, and continue to broaden their education in implant dentistry once in practice, as compared with graduates of predoctoral programs lacking a formal implant curriculum. 28,29 Acknowledging these challenges, previous surveys have sought to evaluate the prevalence of implant education at U.S. dental schools from the 1970s to the early to mid-2000s, as well as student perceptions of preparedness for providing implant therapy upon graduation. The most recent report on predoctoral implant education trends was by Lim et al., 23 but the data acquired in their study are now over 12 years old. In the face of new technological advances and faculty turnover due to retirement, their data require updating and further clarification to remain relevant. In addition, there has been a paucity of research to determine the structure and specifics of implant therapy education at the predoctoral level across U.S. dental schools. The aim of our study was therefore to provide an overview of current predoctoral implant programs in the United States, including curricular characteristics and clinical practices regarding implant therapy and program directors characteristics. Methods This study was approved by the University of Iowa Institutional Review Board (# ). Predoctoral implant program directors were identified for each of the 64 accredited dental schools as listed on the American Dental Association s DDS/ DMD programs webpage. 30 The appropriate contacts were subsequently researched on each institution s webpage. Contact was made via to verify the individual s position as predoctoral implant program director. As a result of these preliminary contacts, four recently established schools (Midwestern University College of Dental Medicine-Illinois, University of New England College of Dental Medicine, East Carolina University School of Dental Medicine, and University of Utah School of Dentistry) responded that their predoctoral implant programs had not yet been formally developed, leaving 60 as the final number of institutions eligible to participate in the study. A draft of a survey instrument was developed to determine the predoctoral implant programs educational practices in the areas of diagnosis and treatment planning and restorative techniques, as well as the program directors characteristics and perceptions of their programs effectiveness in preparing students to provide implant therapy upon graduation. After feedback from two senior faculty members at The University of Iowa College of Dentistry and Dental Clinics, the survey was finalized (the full survey instrument is available from the corresponding author). The electronic survey tool Qualtrics (Provo, UT, USA) was used to create a digital version of the survey and record data from the respondents. The survey was divided into three sections. The first section (15 questions) asked for information about the predoctoral implant program directors, in order to ascertain whether training, years of experience, and tenure as program director influenced their perceptions of student preparedness. The second section (12 questions) focused on the predoctoral implant program s educational methods in relation to diagnosis, treatment planning, and restorative modalities primarily taught. The third section (two questions) requested the program directors subjective perceptions of student preparedness, as well as what educational components they perceived most beneficial in preparing students to provide implant therapy after graduation. 266 Journal of Dental Education Volume 79, Number 3

3 A letter detailing the objective of the study as well as a link to complete the survey via Qualtrics was ed to each predoctoral implant program director on August 12, If a survey response or was not received from the institution, a follow-up was sent every three to four weeks until November 5, 2013, for up to four reminders. If no response was obtained after these attempts, the institution was considered to be a nonrespondent. Recipients of the s were able to opt out by responding to any of the messages indicating they did not wish to be contacted or by simply not completing the survey. Additionally, respondents had the option to selectively answer some or all of the survey once they began. Any request not to be contacted again was respected by the research team, and no further attempt at contact was made. The data were exported to SPSS version 22.0 software (IBM Corp., Research Triangle Park, NC, USA) for analysis. Simple descriptive statistics (frequency distributions and pie charts) were used to summarize the data. Region of implant program location was one of the independent variables of interests. Responses of the implant program directors were the outcome (dependent) variables. Association between responding program directors and geographic regions was examined by global chi-square tests. All statistical tests were two-sided, and a p-value of <0.05 was deemed to be statistically significant. Results A total of 52 of the 60 directors of eligible predoctoral implant programs responded to the survey, for a response rate of 87%. Males comprised 74.5% of the program directors, and 50% were aged 51 years (Table 1). The participating institutions were spread across the United States, with a high of 27.5% of respondents being from the Northeast region to a low of 5.9% from the Southwest region. A majority of the program directors (56.9%) had been practicing dentistry for 21 years. The vast majority of the program directors (86.3%) had obtained specialty training. Of the 44 program directors who responded to the question about specialty certification, 81.8% held certification in prosthodontics, 15.9% in periodontics, and 2.3% in oral and maxillofacial surgery. Of the 23 program directors who responded to the question about board certification, 73.9% were boardcertified in prosthodontics, 21.7% in periodontics, and 4.3% in oral and maxillofacial surgery. Of the 44 program directors who responded to the question on implant therapy training, 84.1% reported having had such training. The institutional characteristics of the responding program directors are summarized in Table 2. When asked with which department they were affiliatied, 44% reported prosthodontics, 40% restorative dentistry, 12% periodontics, and 4% oral and maxillofacial surgery (Table 2). Regarding number of years working in their current institution, 34.7% of these program directors had been there for 5 years, 14.3% for 6 to 10 years, 26.5% for 11 to 20 years, and 24.5% for 21 years. Close to 30% had served as predoctoral implant program director for 2 years; only 2% had served in that position for 21 years. The respondents reported that the restorative dentistry department is involved in the predoctoral implant program at all the schools, while periodontics and oral and maxillofacial surgery departments are involved in 86.5% and prosthodontics in 82.7%. Pediatric dentistry and dental public health were the only departments not involved in the predoctoral implant program at any of these schools. The program directors were also asked about the educational characteristics of their predoctoral implant programs. These directors reported that some implant education is taking place across all four years of the curriculum but is more prevalent in the final two years: 9.6% reported the implant program being integrated into the first year, 59.6% into the second year, 80.8% into the third year, and 65.4% into the fourth year (Table 3). Regarding the number of implant systems to which their predoctoral students are exposed, 40% of these program directors reported one, while 26% reported two, 18% reported three, and 16% reported four or more. Apart from the didactic component, 90.4% of these directors said simulation exercises without direct patient care were included in their programs, and 94.2% said their programs included direct patient care under supervision. When asked which restorative implant modalities are taught in their clinics, 96.2% of the program directors reported posterior single implant-supported single crown, and 88.5% reported mandibular implantretained overdentures. Other modalities reported at lower levels were anterior implant-supported single crown (61.5%), maxillary implant-retained overdenture (32.7%), posterior three-unit implantsupported fixed partial denture (FPD) (59.6%), and anterior three-unit implant-supported FPD (42.3%). Other modalities mentioned (7.7%) were cantilevered implant-supported FPDs, implant-assisted RPDs, March 2015 Journal of Dental Education 267

4 Table 1. Characteristics of U.S. predoctoral implant program directors, by percentage of total respondents to each question Characteristic (Number of Respondents) Response % of Respondents Gender (N=51) Male 74.5% Female 25.5% Age range in years (N=50) % % % 51 50% Region of United States (N=51) Northwest 15.7% North Central 19.6% Northeast 27.5% Southwest 5.9% South Central 11.8% Southeast 19.6% Number of years practicing dentistry (N=51) <1 year 0 1 to 2 years 0 3 to 4 years 0 5 to 6 years 7.8% 7 to 10 years 2% 11 to 15 years 17.6% 16 to 20 years 15.7% 21 years 56.9% Specialty training (N=51) Yes 86.3% No 13.7% Specialty certification (N=44) Dental public health 0 Endodontics 0 Oral and maxillofacial pathology 0 Oral and maxillofacial radiology 0 Oral and maxillofacial surgery 2.3% Orthodontics 0 Pediatric dentistry 0 Periodontics 15.9% Prosthodontics 81.8% Board certification (N=23) Dental public health 0 Endodontics 0 Oral and maxillofacial pathology 0 Oral and maxillofacial radiology 0 Oral and maxillofacial surgery 4.3% Orthodontics 0 Pediatric dentistry 0 Periodontics 21.7% Prosthodontics 73.9% Implant therapy training (N=44) Yes 84.1% No 15.9% bar over denture, and full-arch fixed/hybrid restorations. Among these directors, 48 (92.3%) reported their schools require students to prepare a surgical guide or a set of surgical guides prior to the surgical implant placement. The clinical techniques and materials used in these predoctoral implant programs are summarized in Figure 1. According to the program directors, a majority of the schools (74.5%) utilize analog surgical guide planning, with 25.5% reporting routine use of digital guided surgery planning software as part of their predoctoral implant programs. All three participating schools in the Southwest region reported routinely using guided surgical planning software as part of their clinical protocol, while only one of eight participating schools in the Northwest region routinely uses guided surgical planning software. When a global chi-square test was used to examine overall differences in routine use of guided surgical planning software as part of the programs clinical protocols in all regions, there were no significant differences among regions (p=0.06). 268 Journal of Dental Education Volume 79, Number 3

5 Table 2. Institutional characteristics of U.S. predoctoral implant program directors, by percentage of total respondents to each question Characteristic (Number of Respondents) Response % of Respondents Department affiliated with (N=50) Dental public health 0 Endodontics 0 Oral and maxillofacial pathology 0 Oral and maxillofacial radiology 0 Oral and maxillofacial surgery 4% Orthodontics 0 Pediatric dentistry 0 Periodontics 12% Prosthodontics 44% Restorative dentistry 40% Number of years working in this institution (N=49) 0 to 5 years 34.7% 6 to 10 years 14.3% 11 to 20 years 26.5% 21 years 24.5% Number of years served as predoctoral implant program director 0 to 2 years 30% (N=50) 3 to 4 years 12% 5 to 6 years 18% 7 to 8 years 14% 9 to 10 years 6% 11 to 15 years 12% 16 to 20 years 6% 21 years 2% Departments involved in predoctoral implant program (N=50) Dental public health 0 Endodontics 1.9% Oral and maxillofacial pathology 1.9% Oral and maxillofacial radiology 28.8% Oral and maxillofacial surgery 86.5% Orthodontics 3.8% Pediatric dentistry 0 Periodontics 86.5% Prosthodontics 82.7% Restorative dentistry 100% With regard to restorative techniques, 81.6% of these program directors reported their schools primarily teach fixture level impression modalities, while 72.9% primarily teach closed tray impression techniques, 50% primarily use stock abutment type, and 63.8% teach cement-retained fixation modality (Figure 1). Close to 77.8% of the North Central schools, 77% of the Northeast schools, and 100% of the Southeast schools reported using closed tray technique, while 71.4% of the Northwest schools reported using open tray technique (p=0.05). There were significant differences among the regions in the type of abutment primarily used. All participating schools in the Northwest region and 66.7% in the South Central region reported utilizing custom abutments as the primary abutment design for their predoctoral implant programs, while the majority of schools in the North Central (62.5%), Northeast (53.8%), Southwest (66.7%), and Southeast (80%) regions reported using stock abutments (p=0.02). The abutment materials used were titanium (90.4% of responding schools), zirconia (55.8%), noble metal (38.5%), and other (1.9%). There were no statistically significant regional variations in preference for the abutment biomaterial. Regional differences were significant with regard to fixation modality, with all Northwest region programs primarily teaching screw-retention, and 90% of Southeast and 87.5% of North Central programs primarily teaching cementretention (p=0.002). The subjective perceptions of the responding predoctoral implant program directors are summarized in Figure 2. Close to 92% of the directors either strongly agreed or agreed that their predoctoral program adequately prepares students to provide routine dental implant therapy for tooth replacement following graduation. None strongly disagreed. Most of these program directors (81.6%) were also of the opinion that direct, supervised patient care is the most beneficial instructional method for students. March 2015 Journal of Dental Education 269

6 Table 3. Curricular characteristics of U.S. predoctoral implant programs, by percentage of total respondents to each question (N=50) Characteristic Response % of Respondents Years of the dental curriculum into which the First year 9.6% predoctoral implant program is integrated Second year 59.6% Third year 80.8% Fourth year 65.4% Number of implant systems to which predoctoral One 40% students are exposed Two 26% Three 18% Four or more 16% Aside from didactic component, exercises involved Simulation exercise (not direct patient care) 90.4% in implant program Direct patient care under supervision 94.2% Restorative implant modalities taught in clinic Posterior single implant-supported single crown 96.2% Anterior implant-supported single crown 61.5% Mandibular implant-retained overdenture 88.5% Maxillary implant-retained overdenture 32.7% Posterior three-unit implant-supported bridge 59.6% Anterior three-unit implant-supported bridge 42.3% Other 7.7% Are students required to prepare a surgical guide or a set of Yes 92.3% surgical guides prior to the surgical implant placement? Discussion Implant dentistry and its related educational components are relatively recent additions to predoctoral curricula. Changes in both implant and abutment design, emerging digital technologies affecting surgical and restorative aspects of care, and recent demographic shifts in U.S. dental school faculty have also influenced the nature, content, and focus of contemporary predoctoral dental implant education. Considering these factors, a moderate degree of heterogeneity with regard to curricular content and clinical methodologies taught from institution to institution could exist. Our cross-sectional survey sought to assess the current status of predoctoral implant program director demographics, curricular characteristics, clinical protocols taught, regional U.S. variations, and directors perceptions of preparedness of their graduating dental students in order to report to the academic dental community the current picture of predoctoral dental implant education. This survey-based study benefited from a high response rate (52/60 eligible institutions; 86.7%) and is a strength of the study. When compared with similar recently published survey studies of dental students, residents, dentists, and dental faculty members, our study s response rate is significantly higher Such a high response rate increases our confidence that the study provides a broad and valuable view of current trends in predoctoral implant education. Demographically, a majority of predoctoral implant program directors in this study were male (74.5%), aged 51 or older (50%), and had been practicing clinical dentistry for 21 or more years (56.9%). The directors also overwhelmingly had specialty training and certification in prosthodontics (81.8%), received formal training in implant dentistry (84.1%), and were board-certified (73.9%). The predominant departmental affiliation of these program directors was in prosthodontics or restorative dentistry (84%). The second most frequent specialty certification cited by these program directors was periodontics (15.9%), yet periodontics departments represented a small fraction of their department affiliations (12%). Interestingly, the program directors with specialty certification in periodontics were board-certified less (21.7%) than the program directors with specialty certification in prosthodontics. These demographic trends likely reflect a perspective in the dental community of implant therapy as a fundamentally restoratively driven discipline, with surgical protocols and training facilitating prosthetic outcomes. As more graduate prosthodontics programs integrate surgical implant training as part of their curricula, it would be interesting to observe how this affects implant 270 Journal of Dental Education Volume 79, Number 3

7 Figure 1. Clinical protocols taught in predoctoral implant programs in study, by percentage of respondents to each question March 2015 Journal of Dental Education 271

8 Figure 2. Perceptions of predoctoral implant program directors regarding students preparedness and most beneficial education method, by percentage of respondents to each question 272 Journal of Dental Education Volume 79, Number 3

9 program director demographics in the future. It can be speculated that the progressive integration of formal surgical training into graduate prosthodontic programs may act as a contributing factor in decreasing the representation of implant program directors with surgical specialty training. Further evaluation of trends shows that a majority of these directors had held the position for less than six years (60%), with roughly one in three (30%) holding the position for two years or less. Brief tenure durations as predoctoral implant program directors exist despite the fact that there is a relatively even distribution among directors with regard to the number of years they have been employed at their current institution (see Figure 3 comparing program director tenure vs. number of years working). Several factors could be influencing this disconnect between the duration of employment and duration of tenure as a program director. The first could be that demographic trends are resulting in a number of aging faculty members exiting the workforce due to retirement, resulting in a more recent cluster of es- tablished, mid/late-career faculty being promoted to the position of predoctoral implant program director. A second factor could be that the nature of the position is relatively transitory, with program directors holding it for a period of five years or less and then being promoted to positions of greater responsibility in their institution. A limitation of our study is that a question specifically addressing the timing or reason for the most recent program director s departure was not included, thus limiting our ability to clarify the cause for these observed trends. This study also elucidated some interesting trends with regard to curricular timing, structure, and clinical protocols taught. Regarding timing, the majority of implant education is incorporated into the curriculum during the third (80.8%) and fourth (65.4%) years of training. Only 9.6% of the directors reported implant training during the first year of dental school. Such timing trends are not surprising, given the large amount of didactic and clinical knowledge that must be assimilated to allow for comprehension of factors related to implant Figure 3. Comparison of predoctoral implant program director tenure and number of years working at current educational institution March 2015 Journal of Dental Education 273

10 therapy. Currently, it appears most institutions are incorporating implant-based education at an early stage in the curriculum. Such timing may or may not be deliberate in an attempt to address recurrent concerns by graduating students that there exists a lack of adequate preparedness upon graduation and is likely institution-specific The majority of the programs in our study also tend to limit students exposure to one (40%) or sometimes two (26%) primary implant systems. Such limitations may serve several purposes. The primary purpose may be to prevent students from becoming confused regarding the myriad of componentry that exists among implant manufacturers and encourage them to focus instead on treatment planning, communication with referrals, and prosthetic principles. Using multiple implant systems simultaneously in a predoctoral program would likely divert already limited time and didactic resources to instruction in individual system-specific components, rather than to system- or manufacturer-independent principles and fundamentals of restorative implant therapy. Second, limiting implant system heterogeneity may also benefit implant program directors from an administrative standpoint as inventory and ordering mechanisms can be simplified across departments, allowing for more time and resources to be spent on educational components. Lastly, academic institutions often receive support from implant manufacturers in the form of donated or reduced-fee componentry. Such educational agreements or grants benefit multiple entities. They enable academic institutions to substantially reduce the cost of implant-based therapies to patients, thereby increasing the pool of financially eligible patients for students, potentially resulting in greater learning potential. These agreements also allow implant manufacturers to familiarize students with a specific implant system when they are first exposed to implant therapies, potentially leading to their selection of that system in practice after graduation. Structurally, the overwhelming majority of predoctoral implant programs in our study offer clinical training to students via both simulated preclinical exercises (90.4%) and supervised direct patient care (94.2%). Such widespread inclusion of both preclinical and supervised clinical experience shows an encouraging trend, given evidence that programs offering both of these learning experiences result in higher confidence levels and greater likelihood of incorporating implant therapy into their practice after graduation ,36 Our survey did not distinguish whether programs offering simulated preclinical exercises included a laboratory component, which is a recognized limitation. Among implant treatment modalities taught clinically, posterior single-tooth implant restorations were taught by the vast majority (96.2%) of programs, with mandibular implantretained overdentures as the second most common (88.5%). Surgical guide preparation and planning are required in a strong majority (92.3%) of these programs. We anticipated such findings, given the relatively high success rates and lower degree of complexity these restorative modalities represent. However, to our surprise, both anterior singletooth implant restorations and posterior three-unit implant-supported FPDs are also being taught in well over half (61.5% and 59.6%, respectively) of these programs. There were no significant differences in restorative modalities taught across different regions in the United States. Given the greater degree of esthetic, prosthetic, and biologic complexity these restorative modalities entail, these data demonstrate a relatively progressive inclusion of more complex implant-based therapies into predoctoral curricula in the past decade. Less than half of the programs in our study currently incorporate either anterior implant-supported FPDs or maxillary implant-retained overdentures (42.3% and 32.7%, respectively) as part of their clinical curricula, likely reflecting the enhanced degree of complexity and training as well as timeframe required to successfully treatment plan and execute such therapeutic modalities. Whether leveraging digital technologies such as cone beam computed tomography (CBCT), guided surgery, and computer-assisted design/ computer-assisted manufacturing (CAD/CAM) abutment/framework design will further bolster the adoption and incorporation of more complex treatment modalities in programs in the coming decade should be of interest to the academic community moving forward. Regarding specific clinical protocols used to execute implant therapy, these program directors reported several trends, some of which were regiondependent. One quarter (25.5%) reported the routine use of guided surgical planning software as part of their programs clinical protocol. All three participating schools in the Southwest region routinely use guided surgical planning software as part of their programs clinical protocol, while only one of eight participating schools in the Northwest region routinely use guided surgical planning software. There was no significant difference between regions with regards to use of guided surgical planning software as 274 Journal of Dental Education Volume 79, Number 3

11 part of the program s clinical protocol. While to the best of our knowledge, there are no previous survey data on routine use of guided surgery technology at the predoctoral level, it is evident that a segment of institutions are adopting such technologies as part of their predoctoral curricula. It remains to be seen if such technology adoption and incorporation will have an impact on clinical curricula moving forward. A clear majority of the directors reported that the primary impression technique taught in their program is the implant/fixture-level impression (81.6%). Again, to our best knowledge, there are no previous data to compare in order to assess temporal trends. A majority of these directors also reported the use of closed tray impression techniques (72.9%) as compared with open tray (27.1%). Among these programs, close to 77.8% in the North Central region, 77% in the Northeast, and 100% in the Southeast use the closed tray technique, while 71.4% in the Northwest use the open tray technique. Clinical perception of reduced complexity and ease of retrieval could be possible reasons why closed tray techniques are being used more than open tray techniques, but the specific rationale for technique selection was not assessed in this survey. Nationally, about the same percentage of predoctoral implant programs use stock (51.1%) and custom (48.9%) abutments as their primary abutment design. Regionally, however, there were significant differences in type of abutment primarily used. All schools in the Northwest and 66.7% in the South Central region utilize custom abutments as the primary abutment design, while the majority of schools in the North Central (62.5%), Northeast (53.8%), Southwest (66.7%), and Southeast (80%) regions use stock abutments. A limitation of this study is that methodology of fabrication (i.e., casting, abutment preparation/modification, or CAD/CAM) of such custom abutments was not delineated. We speculate that the near even use of stock and custom abutments nationally and the unilateral use of custom abutments by Northwest institutions represent incorporation of CAD/CAM digital technology into predoctoral restorative curricula. Such incorporation could be attributed to decreasing costs associated with these abutments when compared with custom cast abutments that utilize noble or high-noble alloys, a desire to standardize abutment design, and/or a desire to incorporate tenets of an individualized health care teaching philosophy. The results of our study show that titanium (93.8%) remains the abutment biomaterial of choice for predoctoral implant programs, with slightly more than half (56.3%) using zirconia and even fewer (39.6%) using noble metal. There were no regional variations in use of the abutment biomaterial. Cement-retained implant restorations remain the primary fixation modality taught (63.8%) in predoctoral implant programs, with slightly more than a third (36.2%) using screw-retention as the primary fixation modality. Whether such trends reflect the clinical preferences of program directors or are based on prosthetic necessity (i.e., due to less than ideal implant angulation and/or positioning) was not assessed in this study. Regional differences were significant with regard to fixation modality, with all Northwest region programs using screw-retention, and 90% of Southeast and 87.5% of North Central programs using cement-retention. This study also sought to gauge the predoctoral implant program directors subjective perceptions of the preparedness of their students with regard to provision of implant therapy. A majority of the respondents responded positively to this question: 36.7% strongly agreed and 55.1% agreed that their graduating students were prepared to provide routine implant therapy upon graduation. Only 8.2% disagreed, and none strongly disagreed. The reasons for selection of the disagree option are unknown as clarifying questions or a comment field was not incorporated into the survey. We can speculate that these directors may feel their institution does not yet have adequate systems, protocols, and/or curricula established or that inadequate patient pools exist to fulfill adequate clinical experiences for the majority of predoctoral students. The majority of these program directors (81.6%) reported that the instructional method they feel is most beneficial to the learning process for dental students is that of direct, supervised patient care. A limitation of this subjective assessment section on our survey is that well-defined metrics regarding what specific measures the directors used to make their assessments of student preparedness are lacking. This is in part due to the difficult nature of standardizing competency metrics, whether at an individual academic institution or across institutions nationally. As well, given the curricular heterogeneity in predoctoral implant education, such universal measures of competence and preparedness have not yet been established. In light of this, a future study to survey program directors with regard to universally acceptable metrics that would be needed to establish competence prior to graduation could be warranted. March 2015 Journal of Dental Education 275

12 Our study demonstrated that many academic dental institutions are now adopting guided surgery protocols, custom abutments, and more complex treatment modalities such as anterior single-tooth implant and posterior implant-supported fixed partial denture restorations. Outcomes assessment studies of predoctoral implant programs are also scant 37,38 and are needed to further evaluate if more advanced implant therapies are successful at the predoctoral level. Future directions for analogous surveys regarding predoctoral implant program structure, clinical curricula, and program directors perceptions should have a strong focus on how next-generation digital technologies are altering or shaping implant education, as well as seeking to establish metrics that can be used as benchmarks to gauge student competence. Finally, given an increased recognition of the role that excess cement plays in peri-implant disease initiation and progression, it would be worthwhile to assess regional and temporal trends in prosthetic fixation of implant restorations, as our study found regional differences with regard to this and other specific clinical protocols. Conclusion The results of this study suggest that while there is a great deal of homogeneity among predoctoral implant program directors at U.S. dental schools, there is a significant degree of heterogeneity in their programs with regard to curricular and clinical practices by region, especially in abutment design and coronal fixation. The findings of this study also point to predoctoral implant programs increasingly incorporating digital technologies in the form of guided surgery planning, custom abutments, and more complex therapeutic strategies. Whether such progressive trends in predoctoral implant education will ameliorate the findings of earlier national evaluations of graduating students and find a higher level of perceived preparedness over time remains an open question. Acknowledgments The authors would like to thank Dr. James Clancy, Dr. Richard Williamson, and Dr. Clark Stanford for their thoughtful evaluations and feedback leading up to this study. Disclosures The authors declare no conflicts of interest with respect to the authorship and publication of this article. REFERENCES 1. Branemark PI. Osseointegration and its experimental background. J Prosthet Dent 1983;50: Lekholm U. Clinical procedures for treatment with osseointegrated dental implants. J Prosthet Dent 1983;50: Zarb GA. Introduction to osseointegration in clinical dentistry. J Prosthet Dent 1983;49: Berglundh T, Persson L, Klinge B. A systematic review of the incidence of biological and technical complications in implant dentistry reported in prospective longitudinal studies of at least 5 years. J Clin Periodontol 2002;29(Suppl 3): Jung RE, Pjetursson BE, Glauser R, et al. A systematic review of the 5-year survival and complication rates of implant-supported single crowns. Clin Oral Implants Res 2008;19: Pjetursson BE, Thoma D, Jung R, et al. A systematic review of the survival and complication rates of implantsupported fixed dental prostheses (FDPs) after a mean observation period of at least 5 years. Clin Oral Implants Res 2012;23(Suppl 6): Papaspyridakos P, Mokti M, Chen CJ, et al. Implant and prosthodontic survival rates with implant fixed complete dental prostheses in the edentulous mandible after at least 5 years: a systematic review. Clin Implant Dent Relat Res 2014;16(5): Att W, Stappert C. Implant therapy to improve quality of life. Quintessence Int 2003;34: Heydecke G, Locker D, Awad MA, et al. Oral and general health-related quality of life with conventional and implant dentures. Community Dent Oral Epidemiol 2003;31: Fillion M, Aubazac D, Bessadet M, et al. The impact of implant treatment on oral health related quality of life in a private dental practice: a prospective cohort study. Health Qual Life Outcomes 2013;11: Heydecke G, Penrod JR, Takanashi Y, et al. Cost-effectiveness of mandibular two-implant overdentures and conventional dentures in the edentulous elderly. J Dent Res 2005;84: Bouchard P, Renouard F, Bourgeois D, et al. Cost-effectiveness modeling of dental implant vs. bridge. Clin Oral Implants Res 2009;20: Vogel R, Smith-Palmer J, Valentine W. Evaluating the health economic implications and cost-effectiveness of dental implants: a literature review. Int J Oral Maxillofac Implants 2013;28: Zitzmann NU, Krastl G, Weiger R, et al. Cost-effectiveness of anterior implants versus fixed dental prostheses. J Dent Res 2013;92:183S Journal of Dental Education Volume 79, Number 3

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