- Email: [email protected]
Survey of prosthodontic service provided by general dentists in Virginia
Survey of prosthodontic service provided by general dentists in Virginia Charles E. Janus, DDS, MS,a Ronald J. Hunt, DDS, MS,b and John W. Unger, DDSc Virginia Commonwealth University, School of Dentistry, Richmond, Va Statement of problem. Activities in prosthodontic treatment may be changing due to prevalence of disease and new treatment options. Studies cite conflicting evidence in regard to prosthodontic services, particularly removable prosthodontics. Purpose. This project was designed to describe the amount of prosthodontic services provided by general dentists in Virginia. Results may enhance understanding practice patterns in Virginia and regions with similar demographics. Material and methods. Licensed Virginia dentists (n=600) were randomly selected from the Virginia Department of Health Professions website. Each individual was mailed a survey of questions about his or her demographics and practice activities with regard to prosthodontics. Results. Of the 333 respondents, 195 provide prosthodontic treatment and function as general dentists. On average, they spend 25% of their practice time providing prosthodontic services (17% fixed and 8% removable). They provide at least 1 complete denture for a mean total of 24.3 patients per year, at least 1 removable partial denture for a mean total of 28.7 patients per year, at least 1 fixed partial denture for a mean total of 23.0 patients per year, at least 1 implant-supported crown for a mean total of 12.3 patients per year, and at least 1 implantsupported fixed partial denture for mean total of 3.3 patients per year. Data were analyzed using descriptive statistics. Data for total population and median income were analyzed with the Wilcoxon signed rank test. Conclusion. Virginia dentists continue to provide considerable numbers of fixed prosthodontic restorations, removable partial dentures, and complete dentures, while providing a growing number of implant-supported restorations. (J Prosthet Dent 2007;97:287-91.)
CLINICAL IMPLICATIONS Dentists can expect a continued demand for both fixed and removable prosthodontic services.
U
tilization of dental services has changed markedly over the past several years due to variation in dental disease and the introduction of new materials, techniques, and treatment options.1,2 General dentists typically spend most of their time treating adults, referring few patients to prosthodontists,3,4 and exhibit considerable diversity in treatment philosophies and fees.3,5-7 The dental workforce has shifted, with recent dental graduating classes bringing greater numbers of women into the profession concurrent with a slight decline in men.8 Although practice patterns of male and female dentists tend to be equivalent, and regression models showed gender of dentists had no effect on total income, the mean number of days worked by female dentists was about 10 percent less than their male counterparts. Therefore, it was concluded that the total numbers of patients seen per year may decrease as more women dentists render treatment.9 Furthermore, gender and practice location have an influence, with male dentists
a
Associate Professor, Department of Prosthodontics. Harry Lyons Professor and Dean. c W. Tyler Haynes Professor and Chairman. b
MAY 2007
providing more prosthodontic services than female dentists, and dentists in private practice providing more fixed prosthodontic treatment than dentists employed in the public dental health settings. Conversely, public health dentists report a higher production of removable prostheses than dentists in private practice.3 Various factors, such as social and demographic traits, perceived need for care by patients, symptoms, and esthetic concerns have been shown to influence activity in the delivery of prosthodontic services.10,11 In regard to removable prosthodontics, there is a growing number of dentists who no longer provide removable complete dentures, responding to the perceived decline in edentulism.12 With greater numbers of patients retaining more teeth and a growing interest in implant-supported restorations, a shift away from removable prosthodontics, with greater emphasis on fixed and implant-supported prosthodontic restorations, has been observed.13,14 Nonetheless, many people may still need complete dentures.15 The number of adults 65 years and older seeking dental treatment has increased.16 They make up a population of patients that are most often in need of prosthodontic treatment, and it is, therefore, reasonable to expect an increase in both fixed and removable THE JOURNAL OF PROSTHETIC DENTISTRY 287
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prosthodontic services. Some estimates further suggest that the need for both complete dentures and removable partial dentures (RPDs) may exceed the supply of dentists over the next 20-year period.17,18 However, while most dental schools still include complete dentures and RPDS in their curriculum, over 15% of the 44 schools responding to a survey are now allowing graduates to complete predoctoral training without providing a required number of RPDs or complete dentures.19,20 Consequently, a concern is rising for the growing number of edentulous patients who may be unable to afford dental implants, compounded by the decreasing opportunities for predoctoral students to develop skills in providing complete dentures to meet this need.21 In regard to implant prosthodontics, over 80% of the 38 schools responding to a survey indicate singletooth implant restorations and implant-retained complete dentures are performed at the predoctoral level.22 While faculty with prosthodontic specialty training are usually responsible for teaching implant prosthodontics, there is currently no predoctoral clinical competency requirement for this treatment.23 The purpose of this study was to gather data about prosthodontic practice activities by surveying Virginia dentists, randomly selected from the Virginia Department of Health Professions website, allowing them to disclose information about themselves, their practices, and types of prosthodontic treatment they render. From these data, an assessment of the current prosthodontic activities can be made in an attempt to corroborate the findings of other studies and better understand how these changes affect dental practices in Virginia and states with similar demographic profiles. Such information on practices could affect continuing education courses, insurance reimbursement, and dental school curriculums.
MATERIAL AND METHODS A list of the names and addresses of all dentists currently licensed to practice dentistry in the Commonwealth of Virginia was downloaded from the Virginia Department of Health Professions website (http:// www.dhp.state.va.us/) in September 2003. From this list, only dentists with mailing addresses within Virginia were selected, which yielded 4132 eligible individuals. One randomly generated number ranging from 1 to 10,000 was assigned to each individual record. The records were then sorted by these numbers and the first 600 individuals were selected as survey participants. Each of the individuals was assigned a unique identification number, which appeared on the survey questionnaire and was linked with the participant’s name and address for survey follow-up purposes. The identified surveys were direct-mailed to the 600 randomly selected dentists. 288
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Included in the mailing was a cover letter stating the purpose of the survey, an invitation to volunteer, assurance that all results would remain confidential, and an explanation that the survey ID number was incorporated in the survey only if a follow-up letter was needed and would not remain with the information provided. In addition, a stamped and addressed return envelope was enclosed. Nonrespondents received 2 additional mailings. When the follow up was complete, the survey ID number and the dentist’s name and address were removed from the data set, assuring that all information was recorded in a manner that prevented survey participant identification. This protocol and method of managing the resulting data was approved by the Virginia Commonwealth University’s institutional review board. Of the 600 mailings, 333 participants responded (56%). Of these 333 respondents, 298 indicated they were practicing, 34 indicated they were retired, and 1 did not respond to this question. Of these 298 practicing dentists, 222 indicated that they provide fixed partial denture (FPD) or RPD prosthesis treatment services. To limit the survey to dentists practicing general dentistry, only 200 respondents who indicated not receiving postdoctoral American Dental Association (ADA)-approved advanced dental training were considered. Of these 200 respondents, 4 sole proprietors and 1 employed dentist were removed due to their high responses on certain treatment questions, over 3 standard deviations from the mean, which led the investigators to conclude that these respondents were not general dentists. This resulted in 195 respondents considered eligible for study.
RESULTS Of the respondents, 76% were men, 28% graduated between 1980 and 1989, and 27% graduated between 1970 and 1979. Table I displays the practice types represented by the respondents, and 57% were sole proprietors in a solo setting. To help investigate whether the survey sample reasonably represented Virginia dentists, the US Census Bureau website (http://factfinder. census.gov/servlet/SAFFPopulation?_submenuId= population_0&_sse=on) was accessed in October 2006. Data on total population and median income for the respondent’s zip codes were compared to the total population and median income for zip codes of Virginia dentists who were not included in the survey or did not respond. The mean total population of the zip codes of the responding dentists was 26,015 and not significantly different from the mean total population of the zip codes of all the other Virginia dentists, which was 28,168 (P=.078). In regard to the median income for zip code regions, the mean for responding Virginia dentists of $53,173 was not significantly different from the VOLUME 97 NUMBER 5
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Table I. Practice types among Virginia general dentist respondents (n=195)
Table II. Mean percentage time spent by Virginia general dentists providing each dental service (n=195)
Type
%
Sole proprietor in solo setting Sole proprietor in group setting Group practice partner or shareholder Employee: salary, commission, or percentage Institutional - prison, public health, school Other
57 7 19 13 3 1
mean income of all other Virginia dentists of $56,151 (P=.096) (Wilcoxon signed rank test). Table II displays the mean percentage time respondents spent providing various dental procedures. A large percentage did not provide implant placement (94%), orthodontic appliances (80%), or periodontal surgical services (83%). Operative dentistry restorations comprised the largest percentage of time per category of service (32%), followed by diagnostic and treatment planning services (17%), and fixed prosthodontics (17%). Table III shows the mean number of patients provided treatment per year, with the particular prosthodontic service listed. Most respondents provide FPDs, implant-supported crowns, RPDs, and complete dentures. Patients provided with FPDs represented the highest mean (23.0 patients), with metal-frame RPDs second (17.1 patients). Most complete dentures provided were not retained with implants (12.8 versus 6.5). The number of patients per year who were provided some combination of complete or RPD prostheses is shown in Table IV. Most respondents provide each of the prosthodontic combinations, with patients receiving both maxillary and mandibular RPDs representing the largest group and complete denture using natural tooth roots (overdenture) being the smallest group. Combining all the categories that included at least 1 complete denture as part of the treatment yields a mean total of 24.3 patients per year. Combining all the categories that include at least 1 RPD as part of the treatment yields a mean total of 34.2 patients per year. Table V displays respondent’s perception about changes in providing complete dentures, RPDs, implant-supported fixed prostheses, and implant-supported removable prostheses for their patients. A total of 54% reported activity in complete dentures to be either ‘‘increasing’’ or ‘‘not changing.’’ A total of 67% reported activity in RPDs to be either ‘‘increasing’’ or ‘‘not changing.’’ In regard to implant-supported fixed prostheses and implant-supported removable prostheses, the largest number of respondents reported this service was ‘‘increasing.’’ The largest proportion of the respondents believed the number of complete dentures and RPDs were ‘‘not changing,’’ while implantMAY 2007
% Not providing service
Diagnostic and treatment planning Endodontic therapy (surgical and nonsurgical) Esthetics (veneers, all ceramic restorations) Fixed prosthodontics (crowns and FPDs) Implant placement Implant restoration Operative dentistry restorations (amalgam, composite resin, inlays) Oral surgery services (extractions, impactions, implants) Orthodontic (fixed and removable appliances) Periodontal (nonsurgical) Periodontal (surgical) Removable prosthodontics (complete dentures or RPDs) Other
4 17
% of Time Mean SD
17 12 7 6
27
6
5
7
17
9
94 34 4
0 2 3 3 32 13
16
7
7
80
1
2
28 83 7
7 6 2 9 8 11
91
3
8
supported FPDs and implant-supported RPDs were ‘‘increasing.’’
DISCUSSION The response rate for the mailed survey was 57%, with 195 general dentist respondents identified. Although the sample size and response rates may be limitations, the respondents’ demographic profiles seem to adequately represent Virginia dentists. The localities (zip codes) in which these general dentists practiced did not differ significantly from the localities of other Virginia dentists in total population or median income. The population in the zip codes where the dentists practiced was used as a measure of population density around the practices of the respondents versus all Virginia dentists. The median income for the zip codes was used as a measure of the relative socioeconomic level of the localities in which the dentists practiced. These nonsignificant differences in population density and socioeconomic level provide evidence that responding dentists practice in localities similar to those in which the remaining Virginia dentists practice. Moreover, the distribution of responding dentists in regard to gender, decade of graduation, and practice setting is similar to the overall population of dentists in the United States.8,9 To consider whether the results from dentists from Virginia may be more broadly applicable to other regions of the United States, census bureau on-line data 289
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Table III. Number of patients treated per year for each prosthodontic service by Virginia general dentist respondents (n=195) % Not providing service
Mean
SD
13 22 51 12 8 10 70 80 91 94 9 99
23.0 12.3 3.3 11.6 17.1 12.8 1.9 2.0 1.3 1.3 14.4 6.3
21.6 20.0 4.7 13.2 16.2 15.9 2.2 3.3 2.3 2.5 16.7 9.5
FPD Implant-supported single crown Implant-supported FPD RPD - only acrylic resin RPD with metal framework Complete denture with no implants Complete denture retained by 2 implants Complete denture retained by 4 implants Complete denture retained by more than 4 implants Complete denture supported by implants Complete denture of any type Other
Table IV. Number of patients treated per year for various prosthodontic service combinations by Virginia general dentist respondents (n=195) % Not providing service
Mean
SD
12 16 15 65 11 15 16 99
9.8 6.1 6.6 1.8 12.5 7.8 7.3 10.0
14.0 8.5 8.2 2.6 15.2 7.9 7.1 8.5
Maxillary and mandibular complete dentures Maxillary complete denture opposing intact or restored dentition Maxillary complete denture opposing mandibular RPD Complete denture using natural tooth roots (overdenture) Maxillary and mandibular RPDs Maxillary RPD opposing intact or restored dentition Mandibular RPD opposing intact or restored dentition Other
Table V. Virginia general dentist respondents’ perception in regard to changes in number of prostheses fabricated in their practices Number of prostheses fabricated are:
Increasing Not changing Decreasing Unsure*
Complete dentures
27 78 7 19
14% 40% 36% 10%
RPDs
36 95 57 7
18% 49% 29% 4%
Implant-supported FPD
Implant-supported RPD
10 39 1 50
63 51 5 76
54% 20% 1% 26%
32% 26% 3% 39%
*Includes ‘‘unsure,’’ ‘‘did not perform the procedure,’’ and missing responses; not included in analysis.
on Virginia were accessed. Virginia’s rank in regard to some key demographic indicators is as follows: percent urban (24th), median household income (12th), percent of population ages 18-64 (3rd), percent of population over age 65 (44th), percent of employed population in managerial, professional, and related occupations (5th), percent employed as health care practitioners and technical occupations (41st), and percent of population over 25 with bachelor’s degree or higher (7th). Among states ranking close in these indicators are Delaware, Maryland, and the District of Columbia in the Mid-Atlantic; North Carolina, South Carolina, Georgia, Louisiana, Kentucky, and Tennessee in the Southeast; Wisconsin, Michigan, Minnesota, South Dakota, Nebraska, and Kansas in the Midwest; and 290
Nevada, New Mexico, and Washington in the West. It may be expected that dentists’ practice patterns would be similar to Virginia’s in states where the demographic characteristics are similar. Responding Virginia dentists spend 49% of their time providing operative or fixed prosthodontic services, and spend 17% of their time in diagnosis and treatment planning. This is consistent with other observations that general dentists spend most of their time treating adults and refer few patients to prosthodontists,3,4 and confirms that much of their practice activity involves fixed restorations. Although 94% of the general dentists do not place implants, 66% do some type of implant-supported restorations. The respondents indicated growing activity in implant dentistry, with 54% VOLUME 97 NUMBER 5
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seeing an increase in implant-supported FPDs and 32% seeing an increase in implant-retained removable dentures. Respondents reported spending an average of 8% of their time providing removable prosthodontic services (Table II), which seems to support the evidence that patients requiring complete and RPDs are declining. However, only 36% report a decrease in complete denture treatment, and only 29% report a decrease in RPD treatment (Table V). This is consistent with studies that have suggested that the population in need of these services will actually increase and possibly exceed the supply of dentists over the next 20 year period.17,18 Of the various prosthodontic services, the largest number of patients received FPDs (mean = 23 patients per year), followed by metal-framework RPDs and complete dentures. While most respondents do not provide implant-supported complete dentures, only 8% do not provide metal-framework RPDs, and only 9% do not provide complete dentures (Table III), suggesting that most general dentists continue to treat patients using removable prostheses. Of the respondents providing various prosthodontic combinations, the largest number of patients receive maxillary and mandibular RPDs, and the smallest number of patients receive overdentures (Table IV). The practice patterns and trends revealed in this survey have potential implications for dentists, their patients, dental school curriculums, dental continuing education courses, and dental insurance plans.
CONCLUSIONS Virginia dentists continue to provide considerable numbers of fixed prosthodontic restorations, RPDs, and complete dentures, while providing a growing number of implant-supported restorations. REFERENCES 1. Joshi A, Douglass CW, Feldman H, Mitchell P, Jette A. Consequences of success: do more teeth translate into more disease and utilization? J Public Health Dent 1996;56:190-7. 2. Manski RJ, Goodman HS, Reid BC, Macek MD. Dental insurance visits and expenditures among older adults. Am J Public Health 2004;94: 759-64. 3. Kronstrom M, Palmqvist S, Soderfeldt B, Carlsson GE. Dentist-related factors influencing the amount of prosthodontic treatment provided. Community Dent Oral Epidemiol 2000;28:185-94. 4. Kronstrom M, Palmqvist S, Eriksson T, Soderfeldt B, Carlsson GE. Practice profile differences among Swedish dentists. A questionnaire study with special reference to prosthodontics. Acta Odontol Scand 1997;55:265-9.
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5. Kronstrom M, Palmqvist S, Soderfeldt B. Prosthodontic decision making among general dentists in Sweden. I: the choice between crown therapy and filling. Int J Prosthodont 1999;12:426-31. 6. Kronstrom M, Palmqvist S, Soderfeldt B. Prosthodontic decision making among general dentists in Sweden. II: the choice between fixed and removable partial dentures. Int J Prosthodont 1999;12:527-33. 7. Kronstrom M, Palmqvist S, Soderfeldt B. Prosthodontic decision making among general dentists in Sweden. III: the choice between fixed partial dentures and single implants. Int J Prosthodont 2000;13:34-40. 8. Brown LJ, Lazar V. Trends in the dental health work force. J Am Dent Assoc 1999;130:1743-9. 9. del Aguila MA, Leggott PJ, Robertson PB, Porterfield DL, Felber GD. Practice patterns among male and female general dentists in a Washington State population. J Am Dent Assoc 2005;136:790-6. 10. Gilbert GH, Branch LG, Orav EJ. Predictors of older adults’ longitudinal dental care use. Ten-year results. Med Care 1990;28:1165-80. 11. Gilbert GH, Duncan RP, Vogel WB. Determinants of dental care use in dentate adults: six-monthly use during a 24-month period in the Florida Dental Care Study. Soc Sci Med 1998;47:727-37. 12. Graser GN. Predoctoral removable prosthodontics education. J Prosthet Dent 1990;64:326-33. 13. Garcia LT, Cronin RJ Jr. The partially edentulous patient: fixed prosthodontics or implant treatment options. Tex Dent J 2003;120:1148-56. 14. Carlsson GE, Omar R. Trends in prosthodontics. Med Princ Pract 2006;15: 167-79. 15. Carlsson GE. Facts and fallacies: an evidence base for complete dentures. Dent Update 2006;33:134-42. 16. Manski RJ, Moeller JF, Maas WR. Dental services. An analysis of utilization over 20 years. J Am Dent Assoc 2001;132:655-64. 17. Douglass CW, Shih A, Ostry L. Will there be a need for complete dentures in the United States in 2020? J Prosthet Dent 2002;87:5-8. 18. Douglass CW, Watson AJ. Future needs for fixed and removable partial dentures in the United States. J Prosthet Dent 2002;87:9-14. 19. Petropoulos VC, Rashedi B. Complete denture education in U.S. dental schools. J Prosthodont 2005;14:191-7. 20. Petropoulos VC, Rashedi B. Removable partial denture education in U.S. dental schools. J Prosthodont 2006;15:62-8. 21. Melton AB. Current trends in removable prosthodontics. J Am Dent Assoc 2000;131:S52-6. 22. Lim MV, Afsharzand Z, Rashedi B, Petropoulos VC. Predoctoral implant education in U.S. dental schools. J Prosthodont 2005;14:46-56. 23. Petropoulos VC, Arbree NS, Tarnow D, Rethman M, Malmquist J, Valachovic R, et al. Teaching implant dentistry in the predoctoral curriculum: a report from the ADEA Implant Workshop’s survey of deans. J Dent Educ 2006;70:580-8. Reprint requests to: DR CHARLES E. JANUS VIRGINIA COMMONWEALTH UNIVERSITY SCHOOL OF DENTISTRY 521 NORTH 11TH ST RICHMOND, VA 23298 FAX: 804-827-1017 E-MAIL: [email protected] 0022-3913/$32.00 Copyright Ó 2007 by The Editorial Council of The Journal of Prosthetic Dentistry.
doi:10.1016/j.prosdent.2007.02.011
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CLINICAL IMPLICATIONS Dentists can expect a continued demand for both fixed and removable prosthodontic services.
U
tilization of dental services has changed markedly over the past several years due to variation in dental disease and the introduction of new materials, techniques, and treatment options.1,2 General dentists typically spend most of their time treating adults, referring few patients to prosthodontists,3,4 and exhibit considerable diversity in treatment philosophies and fees.3,5-7 The dental workforce has shifted, with recent dental graduating classes bringing greater numbers of women into the profession concurrent with a slight decline in men.8 Although practice patterns of male and female dentists tend to be equivalent, and regression models showed gender of dentists had no effect on total income, the mean number of days worked by female dentists was about 10 percent less than their male counterparts. Therefore, it was concluded that the total numbers of patients seen per year may decrease as more women dentists render treatment.9 Furthermore, gender and practice location have an influence, with male dentists
a
Associate Professor, Department of Prosthodontics. Harry Lyons Professor and Dean. c W. Tyler Haynes Professor and Chairman. b
MAY 2007
providing more prosthodontic services than female dentists, and dentists in private practice providing more fixed prosthodontic treatment than dentists employed in the public dental health settings. Conversely, public health dentists report a higher production of removable prostheses than dentists in private practice.3 Various factors, such as social and demographic traits, perceived need for care by patients, symptoms, and esthetic concerns have been shown to influence activity in the delivery of prosthodontic services.10,11 In regard to removable prosthodontics, there is a growing number of dentists who no longer provide removable complete dentures, responding to the perceived decline in edentulism.12 With greater numbers of patients retaining more teeth and a growing interest in implant-supported restorations, a shift away from removable prosthodontics, with greater emphasis on fixed and implant-supported prosthodontic restorations, has been observed.13,14 Nonetheless, many people may still need complete dentures.15 The number of adults 65 years and older seeking dental treatment has increased.16 They make up a population of patients that are most often in need of prosthodontic treatment, and it is, therefore, reasonable to expect an increase in both fixed and removable THE JOURNAL OF PROSTHETIC DENTISTRY 287
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prosthodontic services. Some estimates further suggest that the need for both complete dentures and removable partial dentures (RPDs) may exceed the supply of dentists over the next 20-year period.17,18 However, while most dental schools still include complete dentures and RPDS in their curriculum, over 15% of the 44 schools responding to a survey are now allowing graduates to complete predoctoral training without providing a required number of RPDs or complete dentures.19,20 Consequently, a concern is rising for the growing number of edentulous patients who may be unable to afford dental implants, compounded by the decreasing opportunities for predoctoral students to develop skills in providing complete dentures to meet this need.21 In regard to implant prosthodontics, over 80% of the 38 schools responding to a survey indicate singletooth implant restorations and implant-retained complete dentures are performed at the predoctoral level.22 While faculty with prosthodontic specialty training are usually responsible for teaching implant prosthodontics, there is currently no predoctoral clinical competency requirement for this treatment.23 The purpose of this study was to gather data about prosthodontic practice activities by surveying Virginia dentists, randomly selected from the Virginia Department of Health Professions website, allowing them to disclose information about themselves, their practices, and types of prosthodontic treatment they render. From these data, an assessment of the current prosthodontic activities can be made in an attempt to corroborate the findings of other studies and better understand how these changes affect dental practices in Virginia and states with similar demographic profiles. Such information on practices could affect continuing education courses, insurance reimbursement, and dental school curriculums.
MATERIAL AND METHODS A list of the names and addresses of all dentists currently licensed to practice dentistry in the Commonwealth of Virginia was downloaded from the Virginia Department of Health Professions website (http:// www.dhp.state.va.us/) in September 2003. From this list, only dentists with mailing addresses within Virginia were selected, which yielded 4132 eligible individuals. One randomly generated number ranging from 1 to 10,000 was assigned to each individual record. The records were then sorted by these numbers and the first 600 individuals were selected as survey participants. Each of the individuals was assigned a unique identification number, which appeared on the survey questionnaire and was linked with the participant’s name and address for survey follow-up purposes. The identified surveys were direct-mailed to the 600 randomly selected dentists. 288
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Included in the mailing was a cover letter stating the purpose of the survey, an invitation to volunteer, assurance that all results would remain confidential, and an explanation that the survey ID number was incorporated in the survey only if a follow-up letter was needed and would not remain with the information provided. In addition, a stamped and addressed return envelope was enclosed. Nonrespondents received 2 additional mailings. When the follow up was complete, the survey ID number and the dentist’s name and address were removed from the data set, assuring that all information was recorded in a manner that prevented survey participant identification. This protocol and method of managing the resulting data was approved by the Virginia Commonwealth University’s institutional review board. Of the 600 mailings, 333 participants responded (56%). Of these 333 respondents, 298 indicated they were practicing, 34 indicated they were retired, and 1 did not respond to this question. Of these 298 practicing dentists, 222 indicated that they provide fixed partial denture (FPD) or RPD prosthesis treatment services. To limit the survey to dentists practicing general dentistry, only 200 respondents who indicated not receiving postdoctoral American Dental Association (ADA)-approved advanced dental training were considered. Of these 200 respondents, 4 sole proprietors and 1 employed dentist were removed due to their high responses on certain treatment questions, over 3 standard deviations from the mean, which led the investigators to conclude that these respondents were not general dentists. This resulted in 195 respondents considered eligible for study.
RESULTS Of the respondents, 76% were men, 28% graduated between 1980 and 1989, and 27% graduated between 1970 and 1979. Table I displays the practice types represented by the respondents, and 57% were sole proprietors in a solo setting. To help investigate whether the survey sample reasonably represented Virginia dentists, the US Census Bureau website (http://factfinder. census.gov/servlet/SAFFPopulation?_submenuId= population_0&_sse=on) was accessed in October 2006. Data on total population and median income for the respondent’s zip codes were compared to the total population and median income for zip codes of Virginia dentists who were not included in the survey or did not respond. The mean total population of the zip codes of the responding dentists was 26,015 and not significantly different from the mean total population of the zip codes of all the other Virginia dentists, which was 28,168 (P=.078). In regard to the median income for zip code regions, the mean for responding Virginia dentists of $53,173 was not significantly different from the VOLUME 97 NUMBER 5
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Table I. Practice types among Virginia general dentist respondents (n=195)
Table II. Mean percentage time spent by Virginia general dentists providing each dental service (n=195)
Type
%
Sole proprietor in solo setting Sole proprietor in group setting Group practice partner or shareholder Employee: salary, commission, or percentage Institutional - prison, public health, school Other
57 7 19 13 3 1
mean income of all other Virginia dentists of $56,151 (P=.096) (Wilcoxon signed rank test). Table II displays the mean percentage time respondents spent providing various dental procedures. A large percentage did not provide implant placement (94%), orthodontic appliances (80%), or periodontal surgical services (83%). Operative dentistry restorations comprised the largest percentage of time per category of service (32%), followed by diagnostic and treatment planning services (17%), and fixed prosthodontics (17%). Table III shows the mean number of patients provided treatment per year, with the particular prosthodontic service listed. Most respondents provide FPDs, implant-supported crowns, RPDs, and complete dentures. Patients provided with FPDs represented the highest mean (23.0 patients), with metal-frame RPDs second (17.1 patients). Most complete dentures provided were not retained with implants (12.8 versus 6.5). The number of patients per year who were provided some combination of complete or RPD prostheses is shown in Table IV. Most respondents provide each of the prosthodontic combinations, with patients receiving both maxillary and mandibular RPDs representing the largest group and complete denture using natural tooth roots (overdenture) being the smallest group. Combining all the categories that included at least 1 complete denture as part of the treatment yields a mean total of 24.3 patients per year. Combining all the categories that include at least 1 RPD as part of the treatment yields a mean total of 34.2 patients per year. Table V displays respondent’s perception about changes in providing complete dentures, RPDs, implant-supported fixed prostheses, and implant-supported removable prostheses for their patients. A total of 54% reported activity in complete dentures to be either ‘‘increasing’’ or ‘‘not changing.’’ A total of 67% reported activity in RPDs to be either ‘‘increasing’’ or ‘‘not changing.’’ In regard to implant-supported fixed prostheses and implant-supported removable prostheses, the largest number of respondents reported this service was ‘‘increasing.’’ The largest proportion of the respondents believed the number of complete dentures and RPDs were ‘‘not changing,’’ while implantMAY 2007
% Not providing service
Diagnostic and treatment planning Endodontic therapy (surgical and nonsurgical) Esthetics (veneers, all ceramic restorations) Fixed prosthodontics (crowns and FPDs) Implant placement Implant restoration Operative dentistry restorations (amalgam, composite resin, inlays) Oral surgery services (extractions, impactions, implants) Orthodontic (fixed and removable appliances) Periodontal (nonsurgical) Periodontal (surgical) Removable prosthodontics (complete dentures or RPDs) Other
4 17
% of Time Mean SD
17 12 7 6
27
6
5
7
17
9
94 34 4
0 2 3 3 32 13
16
7
7
80
1
2
28 83 7
7 6 2 9 8 11
91
3
8
supported FPDs and implant-supported RPDs were ‘‘increasing.’’
DISCUSSION The response rate for the mailed survey was 57%, with 195 general dentist respondents identified. Although the sample size and response rates may be limitations, the respondents’ demographic profiles seem to adequately represent Virginia dentists. The localities (zip codes) in which these general dentists practiced did not differ significantly from the localities of other Virginia dentists in total population or median income. The population in the zip codes where the dentists practiced was used as a measure of population density around the practices of the respondents versus all Virginia dentists. The median income for the zip codes was used as a measure of the relative socioeconomic level of the localities in which the dentists practiced. These nonsignificant differences in population density and socioeconomic level provide evidence that responding dentists practice in localities similar to those in which the remaining Virginia dentists practice. Moreover, the distribution of responding dentists in regard to gender, decade of graduation, and practice setting is similar to the overall population of dentists in the United States.8,9 To consider whether the results from dentists from Virginia may be more broadly applicable to other regions of the United States, census bureau on-line data 289
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Table III. Number of patients treated per year for each prosthodontic service by Virginia general dentist respondents (n=195) % Not providing service
Mean
SD
13 22 51 12 8 10 70 80 91 94 9 99
23.0 12.3 3.3 11.6 17.1 12.8 1.9 2.0 1.3 1.3 14.4 6.3
21.6 20.0 4.7 13.2 16.2 15.9 2.2 3.3 2.3 2.5 16.7 9.5
FPD Implant-supported single crown Implant-supported FPD RPD - only acrylic resin RPD with metal framework Complete denture with no implants Complete denture retained by 2 implants Complete denture retained by 4 implants Complete denture retained by more than 4 implants Complete denture supported by implants Complete denture of any type Other
Table IV. Number of patients treated per year for various prosthodontic service combinations by Virginia general dentist respondents (n=195) % Not providing service
Mean
SD
12 16 15 65 11 15 16 99
9.8 6.1 6.6 1.8 12.5 7.8 7.3 10.0
14.0 8.5 8.2 2.6 15.2 7.9 7.1 8.5
Maxillary and mandibular complete dentures Maxillary complete denture opposing intact or restored dentition Maxillary complete denture opposing mandibular RPD Complete denture using natural tooth roots (overdenture) Maxillary and mandibular RPDs Maxillary RPD opposing intact or restored dentition Mandibular RPD opposing intact or restored dentition Other
Table V. Virginia general dentist respondents’ perception in regard to changes in number of prostheses fabricated in their practices Number of prostheses fabricated are:
Increasing Not changing Decreasing Unsure*
Complete dentures
27 78 7 19
14% 40% 36% 10%
RPDs
36 95 57 7
18% 49% 29% 4%
Implant-supported FPD
Implant-supported RPD
10 39 1 50
63 51 5 76
54% 20% 1% 26%
32% 26% 3% 39%
*Includes ‘‘unsure,’’ ‘‘did not perform the procedure,’’ and missing responses; not included in analysis.
on Virginia were accessed. Virginia’s rank in regard to some key demographic indicators is as follows: percent urban (24th), median household income (12th), percent of population ages 18-64 (3rd), percent of population over age 65 (44th), percent of employed population in managerial, professional, and related occupations (5th), percent employed as health care practitioners and technical occupations (41st), and percent of population over 25 with bachelor’s degree or higher (7th). Among states ranking close in these indicators are Delaware, Maryland, and the District of Columbia in the Mid-Atlantic; North Carolina, South Carolina, Georgia, Louisiana, Kentucky, and Tennessee in the Southeast; Wisconsin, Michigan, Minnesota, South Dakota, Nebraska, and Kansas in the Midwest; and 290
Nevada, New Mexico, and Washington in the West. It may be expected that dentists’ practice patterns would be similar to Virginia’s in states where the demographic characteristics are similar. Responding Virginia dentists spend 49% of their time providing operative or fixed prosthodontic services, and spend 17% of their time in diagnosis and treatment planning. This is consistent with other observations that general dentists spend most of their time treating adults and refer few patients to prosthodontists,3,4 and confirms that much of their practice activity involves fixed restorations. Although 94% of the general dentists do not place implants, 66% do some type of implant-supported restorations. The respondents indicated growing activity in implant dentistry, with 54% VOLUME 97 NUMBER 5
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seeing an increase in implant-supported FPDs and 32% seeing an increase in implant-retained removable dentures. Respondents reported spending an average of 8% of their time providing removable prosthodontic services (Table II), which seems to support the evidence that patients requiring complete and RPDs are declining. However, only 36% report a decrease in complete denture treatment, and only 29% report a decrease in RPD treatment (Table V). This is consistent with studies that have suggested that the population in need of these services will actually increase and possibly exceed the supply of dentists over the next 20 year period.17,18 Of the various prosthodontic services, the largest number of patients received FPDs (mean = 23 patients per year), followed by metal-framework RPDs and complete dentures. While most respondents do not provide implant-supported complete dentures, only 8% do not provide metal-framework RPDs, and only 9% do not provide complete dentures (Table III), suggesting that most general dentists continue to treat patients using removable prostheses. Of the respondents providing various prosthodontic combinations, the largest number of patients receive maxillary and mandibular RPDs, and the smallest number of patients receive overdentures (Table IV). The practice patterns and trends revealed in this survey have potential implications for dentists, their patients, dental school curriculums, dental continuing education courses, and dental insurance plans.
CONCLUSIONS Virginia dentists continue to provide considerable numbers of fixed prosthodontic restorations, RPDs, and complete dentures, while providing a growing number of implant-supported restorations. REFERENCES 1. Joshi A, Douglass CW, Feldman H, Mitchell P, Jette A. Consequences of success: do more teeth translate into more disease and utilization? J Public Health Dent 1996;56:190-7. 2. Manski RJ, Goodman HS, Reid BC, Macek MD. Dental insurance visits and expenditures among older adults. Am J Public Health 2004;94: 759-64. 3. Kronstrom M, Palmqvist S, Soderfeldt B, Carlsson GE. Dentist-related factors influencing the amount of prosthodontic treatment provided. Community Dent Oral Epidemiol 2000;28:185-94. 4. Kronstrom M, Palmqvist S, Eriksson T, Soderfeldt B, Carlsson GE. Practice profile differences among Swedish dentists. A questionnaire study with special reference to prosthodontics. Acta Odontol Scand 1997;55:265-9.
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5. Kronstrom M, Palmqvist S, Soderfeldt B. Prosthodontic decision making among general dentists in Sweden. I: the choice between crown therapy and filling. Int J Prosthodont 1999;12:426-31. 6. Kronstrom M, Palmqvist S, Soderfeldt B. Prosthodontic decision making among general dentists in Sweden. II: the choice between fixed and removable partial dentures. Int J Prosthodont 1999;12:527-33. 7. Kronstrom M, Palmqvist S, Soderfeldt B. Prosthodontic decision making among general dentists in Sweden. III: the choice between fixed partial dentures and single implants. Int J Prosthodont 2000;13:34-40. 8. Brown LJ, Lazar V. Trends in the dental health work force. J Am Dent Assoc 1999;130:1743-9. 9. del Aguila MA, Leggott PJ, Robertson PB, Porterfield DL, Felber GD. Practice patterns among male and female general dentists in a Washington State population. J Am Dent Assoc 2005;136:790-6. 10. Gilbert GH, Branch LG, Orav EJ. Predictors of older adults’ longitudinal dental care use. Ten-year results. Med Care 1990;28:1165-80. 11. Gilbert GH, Duncan RP, Vogel WB. Determinants of dental care use in dentate adults: six-monthly use during a 24-month period in the Florida Dental Care Study. Soc Sci Med 1998;47:727-37. 12. Graser GN. Predoctoral removable prosthodontics education. J Prosthet Dent 1990;64:326-33. 13. Garcia LT, Cronin RJ Jr. The partially edentulous patient: fixed prosthodontics or implant treatment options. Tex Dent J 2003;120:1148-56. 14. Carlsson GE, Omar R. Trends in prosthodontics. Med Princ Pract 2006;15: 167-79. 15. Carlsson GE. Facts and fallacies: an evidence base for complete dentures. Dent Update 2006;33:134-42. 16. Manski RJ, Moeller JF, Maas WR. Dental services. An analysis of utilization over 20 years. J Am Dent Assoc 2001;132:655-64. 17. Douglass CW, Shih A, Ostry L. Will there be a need for complete dentures in the United States in 2020? J Prosthet Dent 2002;87:5-8. 18. Douglass CW, Watson AJ. Future needs for fixed and removable partial dentures in the United States. J Prosthet Dent 2002;87:9-14. 19. Petropoulos VC, Rashedi B. Complete denture education in U.S. dental schools. J Prosthodont 2005;14:191-7. 20. Petropoulos VC, Rashedi B. Removable partial denture education in U.S. dental schools. J Prosthodont 2006;15:62-8. 21. Melton AB. Current trends in removable prosthodontics. J Am Dent Assoc 2000;131:S52-6. 22. Lim MV, Afsharzand Z, Rashedi B, Petropoulos VC. Predoctoral implant education in U.S. dental schools. J Prosthodont 2005;14:46-56. 23. Petropoulos VC, Arbree NS, Tarnow D, Rethman M, Malmquist J, Valachovic R, et al. Teaching implant dentistry in the predoctoral curriculum: a report from the ADEA Implant Workshop’s survey of deans. J Dent Educ 2006;70:580-8. Reprint requests to: DR CHARLES E. JANUS VIRGINIA COMMONWEALTH UNIVERSITY SCHOOL OF DENTISTRY 521 NORTH 11TH ST RICHMOND, VA 23298 FAX: 804-827-1017 E-MAIL: [email protected] 0022-3913/$32.00 Copyright Ó 2007 by The Editorial Council of The Journal of Prosthetic Dentistry.
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