J Dent Educ. 70(9): 956-964 2006
© 2006 American Dental Education Association
Milieu in Dental School and Practice |
Fluoride Knowledge and Prescription Practices Among Dentists
Sena Narendran, B.D.S., D.D.P.H., M.Sc.;
Jarvis T. Chan, D.D.S., Ph.D.;
Stewart D. Turner, Ph.D.;
Harris J. Keene, D.D.S.
Key words: fluorides, supplement, prescription, knowledge, dental education, fluoride testing, continuing education
Submitted for publication 02/26/06;
accepted 06/02/06
 |
Abstract
|
|---|
The purpose of this study was to assess dentists’ knowledge about fluorides as well as their prescription practices. The study population consists of all general and pediatric dentists in Houston, and the sample consists of 360 general and forty-one pediatric dentists. Data were collected with a self-administered mail questionnaire, which consisted of thirteen open-ended and twenty-nine precoded items. After three mailings, the effective response rate was 46.4 percent. Respondents had been in practice on an average of 18.9 ±6.6 years; the majority were male. More than 75 percent of respondents believed fluoride level in drinking water is an important determinant of fluoride supplement prescription, and 29 percent felt the same about a patient’s weight. The correct ages at which to begin (six months) and to discontinue (sixteen years) the fluoride supplements to children were identified by 14.7 and 14.9 percent of the respondents, respectively. Only 6.7 percent of those prescribing fluoride supplements routinely tested the fluoride level in the patient’s drinking water. Even though pediatric and general dentists differed in certain items, the two groups did not differ significantly in prescribing fluorides (OR=2.4, 95% CI=0.94, 6.27). Deficiencies and ambiguity in respondents’ fluorides knowledge as well as prescription practices indicated a need for educational interventions.
Following the success of water fluoridation as well as fluoride supplement trials during the 1940s, the Council on Dental Therapeutics of the American Dental Association (ADA)1 published its first fluoride dosage schedule in 1958. The American Academy of Pediatrics (AAP)2 published its first fluoride supplement dosage in 1972. Subsequently, various national associations,3–6 federal agencies,7 and researchers8 have proposed revisions to the fluoride supplement schedule, particularly in light of increased availability of fluorides from multiple sources. It is believed that increased availability of fluorides has resulted in an increased prevalence of dental fluorosis9; such an increase is generally seen in the milder forms of fluorosis with the increase in the most severe forms being minimal or negligible. The fluoride schedule has undergone periodic revisions, with the general trend being a reduction in the fluoride supplement dosage and/or downward adjustments of fluoride levels in drinking water. During 1979, the existing fluoride schedule was independently revised by the ADA, American Association of Pediatric Dentistry (AAPD), and AAP.3–4 Revised recommendations from these three organizations were somewhat similar, with minor differences in the ages at which fluoride supplements should be started and discontinued. The new recommendations were reiterated by these associations during the late 1980s.5,6
Some researchers9 believe that the prevalence of dental fluorosis continued to increase during the 1980s and 1990s, which led to further revisions to the fluoride schedule in the early 1990s. In their secondary analyses of data from 1930 to 1980, researchers found the highest increase in the prevalence of fluorosis among children living in suboptimally fluoridated areas from 6.5 to 15.5 percent. Lack of consensus exists among researchers: some support the retention of the existing fluoride schedule,10 while others feel strongly about reducing11 or completely eliminating12 the fluoride supplement as a caries prevention agent. As lifelong learners, dentists are bound to pay attention to the equivocal evidence for fluoride supplementation. It is not certain how the conflicting messages from the research community have impacted the fluoride knowledge of dental practitioners as well as their fluoride prescription practices.
Diffusion of new knowledge among health care providers including dental practitioners is a slow process. Various barriers, outlined in Rogers’s theory of innovation diffusion, impede the dissemination process of new knowledge as well as technical advances among the practicing community.13 The barriers to diffusion include relative advantage, economics, incompatibility with existing value system, and complexity of the innovation. Following publication of the revised fluoride supplementation schedule by the ADA, AAP, and AAPD in the late 1970s, a series of studies examined various health care providers’ knowledge and their prescription practices: dentists,14 pediatric dentists,15 family physicians,16–17 and pediatricians.18 These studies were conducted at the local, state, and national levels; two local studies were done in Houston.17–18 The general consensus among the studies was that health care providers possessed inadequate knowledge about fluoride supplements, which resulted in inappropriate fluoride prescription.
Following a workshop in 1994, three professional organizations jointly recommended a new fluoride supplement schedule.19–21 Studies about health care providers’ knowledge about fluoride supplements and prescription practices following the 1990 recommendations appear to be sparse. In one study that investigated the phenomena among pediatric faculty members in North Carolina,21 more than 90 percent of respondents assessed the fluoride needs of the patients. While 87.5 percent started supplements at the appropriate age, a lesser proportion was knowledgeable of the correct fluoride dosage. Similar studies among dental practitioners, however, are lacking. Despite the revisions to the fluoride schedule in the 1990s by the professional associations, yet another set of new guidelines7 was published by the Centers for Disease Control and Prevention (CDC) in 2001.
Dental caries, the most common childhood disease, is preventable with a judicious preventive regimen including fluorides. Thus, it is important for dental practitioners, particularly general and pediatric dentists, to have a thorough knowledge of fluorides as well as their appropriate use. The objectives of this study were to investigate dentists’ knowledge about fluorides as well as their prescription practices and to ascertain the trends in these phenomena among dentists in Houston as a follow-up to the previous studies.
|
Materials and Methods
|
|---|
The study population consisted of 401 dentists, including 360 general dentists and forty-one pediatric dentists, practicing in Houston, Texas. The Texas State Board of Dental Examiners (TSBDE) provided the sampling frame to the investigators, which included more than 1,200 dentists licensed to practice in Houston. First, the general dental practitioners were chosen by a simple random sampling method from the master list of dentists. All pediatric dentists on the list were then added to the chosen random sample of general dentists. Data were collected by a self-administered mail questionnaire, which consisted of forty-two items, of which twenty-nine were precoded and thirteen open-ended.
The CDC provided questionnaires from previous studies,22 and we developed an initial set of questions that was circulated for review and consultation by researchers at two other academic institutions and the CDC. Based on discussions in conference calls among the investigators and researchers, a draft questionnaire was developed. The draft questionnaire was pilot-tested among dental faculty members who were also part-time private practitioners, and revisions were made. The survey instrument in its final form collected data on demographics, types of dental practice, fluoride knowledge, attitude towards fluoride supplements, and fluoride prescription practices. Items on knowledge investigated factors affecting fluoride prescription practices as well as those responsible for excessive exposure to fluoride. Additional items assessed fluoride dosage for different ages living in communities with certain fluoride levels in the water, as well as the ages at which to commence and stop fluoride supplements.
After three mailings, a total of 183 completed questionnaires were returned for an effective response rate of 46.4 percent; these included 159 general and twenty-four pediatric dentists, whose responses for the majority of the questionnaire items did not differ significantly. The few items on which the two groups of dental providers differed significantly are described in the results section. Respective response rates for general and pediatric dentists were 44.2 and 58.5 percent. Data were appropriately coded and entered into the data editor of the statistical packages for social sciences, SPSS®. The whole data set was scrutinized for accuracy of data entry and coding, and the subsequent statistical analysis consisted of a descriptive and an analytic component.
The descriptive phase examined the knowledge, attitude, and fluoride recommendations of dentists practicing in Houston as well as their demographic attributes. A majority of the questionnaire data was categorical, and the results of such data are presented mainly in the form of percentages/proportions and/or frequency distribution. Medians, means, and standard deviations represent the continuous variables such as age, number of patients, and continuing education hours. Some of the questionnaire items were on a five-point scale: strongly agree, agree, not sure, disagree, and strongly disagree. For analytical tests, the first two responses (strongly agree and agree) were grouped together as "agree," and the last two (disagree and strongly disagree) into "disagree" categories. Similarly, the five-point items on importance (very important to not at all important) were collapsed into three categories: important, neutral, and not important. Respondents who graduated after 1980 were classified as "post-1980" graduates and those graduated before 1980 as "pre-1980" graduates. Dentists who had been in practice for less than twenty years were classified as "experienced" dentists, and those with twenty years or more experience as "more experienced" practitioners. Analytical bivariate tests (2 x 2 contingency tables) computed odds ratios (OR) as well as chi squared statistic, both of which investigated relationships between dependent variables (knowledge of fluorides, fluoride prescription) and independent variables (years in practice, years since graduation, etc.). The level of significance for the analytical tests was set at alpha less than or equal to 0.05.
|
Results
|
|---|
Most respondents to the survey were males (73.8 percent), and the ethnic distribution was 66.8 percent Non-Hispanic Whites, 9.1 percent Asians, 5.9 percent Hispanics, 4.3 percent Non-Hispanic Blacks, and 12.8 percent from various other ethnic groups (Table 1
). The average number of dentists, dental hygienists, and dental assistants among respondents’ practices were 1.6, 1.2, and 2.2 respectively. The study population predominantly consisted of experienced practitioners who had been in practice for nearly twenty years with a mean of 18.9±1.5 years. The average number of patients who are less than sixteen years of age seen by the respondents was nearly twenty per week. Slightly more than one-half reported that they do not prescribe fluoride supplements. Nearly one half of the respondents (48.9 percent), however, reported prescribing fluoride supplements, and 6.7 percent of those prescribing fluoride supplements routinely analyzed fluoride levels in the drinking water of their patients. The mean number of weekly water analyses performed/requested by respondents was 0.3±1.9, and the mean number of fluoride prescriptions written per week was 1.9±6.6. Similar values for those prescribing fluoride supplements were 0.7±3.0 and 6.9±15.3.
A wide range of responses were reported to the question about the appropriate age at which to begin fluoride supplements (Figure 1). One-third of those prescribing fluoride supplements indicated that fluoride supplements should be started after two years of age. Figure 2 shows varying responses to the appropriate age at which fluoride supplements should be discontinued. The correct ages at which to begin (six months) and to discontinue (sixteen years) fluoride supplements to children were identified by 14.7 and 14.9 percent of the respondents, respectively. While the incorrect reported ages at which to begin prescribing fluoride supplements ranged from prenatal to greater than twenty-four months, the range for discontinuing the supplements was seven to fifteen years.
Table 2 shows respondents’ knowledge about factors affecting fluoride supplement prescription to a child. While nearly three-fourths of the respondents identified fluoride level in water at home as well as patients’ age as important factors to be considered before prescribing fluoride supplements, a lesser proportion of the respondents cited the patient’s caries activity (61.7 percent) and fluorides prescribed by other health care providers (59.6 percent). Significantly lower proportions reported that the recommended fluoride dosage schedule (54.1 percent), patients’ weight (29 percent), parents’ caries activity (54.1 percent), siblings’ caries activity (47.5 percent), and fluoride dentifrices (42.3 percent) affected their fluoride prescription practices. All factors listed in the table must be considered by dentists before prescribing fluorides.
One of the items in the questionnaires investigated respondents’ knowledge of factors responsible for excessive fluoride exposure to children less than six years of age (Table 3). Almost all respondents (98.9 percent) correctly reported that fluoride mouth rinses could not be a factor in excessive fluoride exposure. While nearly 60 percent believed that fluoride in drinking water could be a factor in excessive exposure to fluoride among children aged less than six years, 26.2 percent attributed the excessive exposure to fluoride in the toothpaste and 15.5 percent to dietary supplements.
View this table:
[in this window]
[in a new window]
|
Table 3. Respondents’ knowledge of possible causes of excessive fluoride exposure among children less than six years old
|
|
Table 4 illustrates respondents’ rating of factors that are important in determining the use of fluoride toothpaste by a two-year-old child. According to most respondents (77.1 percent), the fluoride level in drinking water was the most important factor, followed by the use of fluoride supplements (69.9 percent), use of baby bottle (63.9 percent), and caries history of siblings (60.7 percent). Nearly 10 percent of respondents failed to answer this question. All factors listed in the table are important in determining the use of fluoride dentifrice.
View this table:
[in this window]
[in a new window]
|
Table 4. Respondents’ rating of important factors in determining fluoride toothpaste use by a two-year-old child (%)
|
|
Analytical tests did not find any significant association between the fluoride prescription practices of respondents and certain demographics or practice attributes (Table 5).The proportion of respondents prescribing fluoride supplements was higher among pediatric than general dentists. No significant difference, however, was observed between the proportions of general dental practitioners and pediatric dentists who prescribed fluoride supplements (OR=2.4, 95% CI=0.94, 6.27). Similarly, respondents’ year of graduation from dental school or type of practice (solo vs. others) was not associated with the fluoride prescription practices.
General and pediatric dentists differed from each other significantly in five items as illustrated in Table 6. While a greater proportion of pediatric dentists believed that excessive levels of fluoride in drinking water result in excessive chronic exposure to fluoride, a higher proportion of general dentists felt the same about ingesting fluoride-containing dentifrice. Pediatric dentists were more than six times more likely than general dentists to know the correct fluoride dosage for a two-year-old child (OR=6.23, 95% CI=2.3, 17.4). Similarly, pediatric dentists were more than 3.5 times more likely than general dentists to consider patient’s caries activity (OR=3.52, 95% CI=1.06, 12.9) as well as siblings’ caries activity (OR=3.57, 95% CI=1.24, 10.78) when prescribing dietary fluoride supplements to a child.
|
Discussion
|
|---|
The response rate to this study is acceptable, despite being lower than the anticipated rate of 55–60 percent. This response rate appears to be the norm for self-administered mail surveys to health care providers,23 particularly dentists. Dental practitioners are inundated with mail surveys to the point that they demonstrate apathy towards such surveys, which could explain the lower than expected response rate in our study. The simple random sampling method of general practitioners and inclusion of all pediatric dentists eliminate any potential selection bias, thus improving the validity of the findings. The present study follows the previous ones, conducted more than ten years apart during 1979 and 1992, in the City of Houston and Harris County, Texas. The study population, however, is slightly different from the previous ones, which did not include general dental practitioners in their samples. Thus, this is the first study in the Greater Houston area to investigate the fluoride knowledge and prescription practices among general dental practitioners.
Despite the respondents being knowledgeable about certain aspects of fluoride supplements, certain gaps in knowledge as well as inappropriate prescription practices were apparent. Deficiencies and ambiguities in the respondents’ knowledge of fluorides as well as the fluoride dosage schedule demonstrate a need for increased educational strategies/interventions, both at the undergraduate and practitioner levels. Addressing educational issues among professional students including residents in pediatric dentistry is important, particularly at a time when uncertainties about the general use of fluorides exist among researchers.10–12 The dental curriculum should emphasize the importance of caries risk assessment as well as comprehensive preventive regimens for dental caries. Instruction on caries risk assessment should include fluoride history, fluoride analysis of drinking water, diet history, and comprehensive clinical investigations. A thorough fluoride history will enlighten dental students as to whether the patient is taking the necessary amount of fluoride supplement or not. Following a fluoride analysis of the patient’s drinking water, dental students can judiciously use the information from the fluoride history to eliminate, decrease, or increase the fluoride supplement dosage of their patients. Therefore, dental students should also be competent in writing fluoride supplement prescriptions, in addition to being knowledgeable about testing fluoride levels in the water.
We believe that almost all dental schools in the United States have fluoride testing equipment at the institution, if not in the undergraduate clinics. It would be an excellent teaching method to equip the undergraduate clinics in dental schools with fluoride testing equipment and teach dental students how to perform the test, which should not consume a lot of clinic time. This teaching strategy will not only increase the knowledge level of dental students about fluorides, but also their awareness for testing fluoride in the drinking water. The increased awareness will be helpful in their future practices and can be reinforced subsequently through appropriate continuing education courses. Further, as community leaders, while in practice they will be comfortable giving advice on fluorides to those who seek such advice as well as to communities at large when needed. As for the practicing dentists, deficiencies/ambiguities in fluoride knowledge and prescription practices could be addressed through continuing education courses, which should include the aforementioned concepts. Such efforts will help to eliminate or minimize the inappropriate fluoride prescription by dentists, particularly the excessive use of fluorides. If not controlled, excess prescription of fluoride supplements will aggravate the perceived increase in the prevalence of fluorosis.
Numerous studies among health care providers in different settings have reported inadequate proportions of respondents testing fluoride levels in a patient’s drinking water before prescribing fluoride supplements.15,21 A previous study in Houston reported that 61 percent of pediatric dentists and 52 percent of pediatricians used the information about fluoride levels in water as an important factor in prescribing fluoride supplements.15 In a study of academic pediatricians, nearly 70 percent assessed the fluoride level in their patients’ drinking water before prescribing fluoride supplements,21 compared to the alarmingly low proportion of less than 10 percent in our study. In our study nearly 67 percent of the pediatric dentists took fluoride levels in water into consideration before prescribing fluoride supplements, which is an improvement over the previously reported 61 percent in the same location. Certain differences between our study and the previous ones could have been due to the inclusion of general dentists in our study, which was not done in the previous studies. The magnitude of differences found between the present study and others, however, could not be explained by sampling variation alone and thus needs further investigation. It appears that substantial proportions of health care providers in academic settings as well as in private practice have failed to adopt the fluoride testing of drinking water despite it being such an important determinant of fluoride supplement prescription. Resources for testing fluoride levels in the drinking water are available at dental schools as well as local and state health departments.15 Further, in-office fluoride testing equipment is available in the commercial market, which may be a quicker and more efficient method of testing fluoride levels in the water than by external agencies. Providers’ oversight in not using this resource as well as deficiencies in their knowledge further reiterate the need for reinforcing the dental school curriculum as well as increasing efforts to offer continuing education courses for dental practitioners.
Surprisingly, pediatric and general dentists differed from each other only in five individual items: two items related to factors causing excessive chronic fluoride exposure in children (fluoride in water and ingestion of tooth paste), correct dosage of fluoride for a two-and-a-half-year-old child consuming water with 0.1 ppm fluoride, and factors to be considered (caries activity of the child and that of siblings) when prescribing fluoride supplement to a child. Out of the five items, a higher proportion of pediatric dentists identified the correct responses for four items except the ingestion of toothpaste being a risk factor in excessive chronic fluoride exposure. General dentists were three times more likely than pediatric dentists to identify correctly that the ingestion of toothpaste with higher levels of fluorides results in excessive exposure to fluoride. The higher knowledge levels of fluoride supplementation reflect the additional training that pediatric dentists received in the use of fluorides.
It is heartening to note that substantial proportions of respondents were knowledgeable about certain aspects of caries prevention, fluorides, and factors affecting the prescription of fluoride supplements. For example, respondents were aware of most risk factors of dental fluorosis such as high fluoride levels in drinking water. A good proportion, however, did not correctly identify fluoride supplements as a risk factor of dental fluorosis as reported in the literature.24 Deficiencies in provider knowledge are not unique to fluorides alone, as similar phenomena have been identified in studies pertaining to oral cancer knowledge among dental practitioners. Academic institutions, professional associations, and public health agencies should bear the responsibility of eliminating deficiencies and ambiguities in fluoride knowledge among health care providers,21 which will then reduce the frequency of inappropriate prescription practices of fluorides. Improved knowledge of fluorides among health care providers, as well as reduction of inappropriate fluoride prescription, will maximize dental caries prevention and minimize such deleterious effects as dental fluorosis.
|
Footnotes
|
|---|
Dr. Narendran is Associate Professor, Department of Community Dentistry, Case School of Dental Medicine; Dr. Chan is Professor, Department of Integrative Biology and Pharmacology, University of Texas Health Science Center at Houston; Dr. Turner is Associate Professor, Department of Neurobiology and Anatomy, University of Texas Health Science Center at Houston; and Dr. Keene is Adjunct Professor, Department of Head and Neck Surgery, M.D. Anderson Cancer Center, Houston. Direct correspondence and requests for reprints to Dr. Sena Narendran, Department of Community Dentistry, Case School of Dental Medicine, 10900 Euclid Avenue, Cleveland, OH 44106; 216-368-1311 phone; 216-368-0145 fax; sena.narendran{at}case.edu.
This study was funded as a special interest project by the Division of Oral Health, Centers for Disease Control and Prevention, through the Center for Health Promotion and Prevention Research, School of Public Health, University of Texas Health Science Center at Houston.
|
REFERENCES
|
|---|
- American Dental Association, Council on Dental Therapeutics. Prescribing dietary fluoride supplements. J Am Dent Assoc 1958;56(10):589–91.[Medline]
- American Academy of Pediatrics, Committee on Nutrition. Fluoride as a nutrient. Pediatr 1972;49(5):456.[Abstract/Free Full Text]
- American Dental Association, Council on Dental Therapeutics. Fluoride compounds. In: Accepted dental therapeutics, 38th ed. Chicago: American Dental Association, 1979:316–38.
- American Academy of Pediatrics, Committee on Nutrition. Fluoride supplementation: revised dosage schedule. Pediatr 1979;63(1):150–2.[Abstract/Free Full Text]
- American Dental Association. A guide to use of fluoride in the prevention of caries. J Am Dent Assoc 1986;113(9):503–65.[Medline]
- American Academy of Pediatrics, Committee on Nutrition. Fluoride supplementation: revised dosage schedule. Pediatr 1986;70(5):758–61.
- Centers for Disease Control. Recommendations for using fluoride to prevent and control dental caries in the United States. MMWR 2001;50(RR 14):1–42.[Medline]
- Riordan PJ. Fluoride supplements in caries prevention: a literature review and proposal for a new dosage schedule. J Public Health Dent 1993;53(3):174–89.[Medline]
- Beltran-Aguilar ED, Griffin SO, Lockwood SA. Prevalence and trends in enamel fluorosis in the United States from the 1930s to the 1980s. J Am Dent Assoc 2002;133(2): 157–65.[Abstract/Free Full Text]
- Moss SJ. The case for retaining the current supplementation schedule. J Public Health Dent 1999;59(4):259–62.[Medline]
- Newbrun E. The case for reducing the current Council on Dental Therapeutics fluoride supplementation schedule. J Public Health Dent 1999;59(4):263–8.[Medline]
- Burt BA. The case for eliminating the use of dietary fluoride supplements for young children. J Public Health Dent 1999;59(4):269–74.[Medline]
- Rogers E. Diffusion of innovation, 5th ed. New York: Free Press, 2003.
- Dillenberg JS, Levy SM, Schroeder DC, Gerston EN, Anderson CJ. Arizona providers’ use and knowledge of fluoride supplements. Clin Prev Dent 1992;14(5):15–26.[Medline]
- Jones KF, Berg JH. Fluoride supplementation: a survey of pediatricians and pediatric dentists. Am J Dis Child 1992;146(12):1488–91.[Abstract]
- Siegel C, Gutgesell ME. Fluoride supplementation in Harris County, Texas. Am J Dis Child 1982;136(1):61–3.[Abstract]
- Kuthy RA, McTigue DJ. Fluoride prescription practices of Ohio physicians. J Public Health Dent 1987;47(4): 172–6.[Medline]
- American Dental Association, Council on Access, Prevention, and Interprofessional Relations. Caries diagnosis and risk assessment. J Am Dent Assoc 1995;126(supplement):2S–26S.
- American Academy of Pediatric Dentistry, Dental Care Committee. Protocol for fluoride therapy: revised dosage schedule. Pediatr Dent 1995;16(Spec Iss 5):24.
- American Academy of Pediatrics, Committee on Nutrition. Fluoride supplementation: revised dosage schedule. Pediatr 1995;79(1):150–2.
- Roberts MW, Keels MA, Sharp MM, et al. Fluoride supplement prescribing and dental referral patterns among academic pediatricians. Pediatr 1998;101:E6.[Medline]
- Moon H, Paik D, Horowitz AM, Kim J. National survey of Korean dentists’ knowledge and opinions: dental caries etiology and prevention. J Public Health Dent 1998;58(1):51–6.[Medline]
- Asch DA, Jedrziewski MK, Christakis NA. Response rates to mail surveys published in medical journals. J Clin Epidemiol 1997;50(10):1129–36.[Medline]
- Pendrys DG, Katz RV. Risks of enamel fluorosis associated with fluoride supplementation, infant formula, and dentifrice use. Am J Epidemiol 1989;130(12):1199–208.[Abstract/Free Full Text]
Top
Abstract
Materials and Methods
