1http://dx.doi.org/10.20396/bjos.v19i0.8656624 Volume 19 2020 e206624 Original Article 1 Department of Community Dentistry, São Paulo State University (UNESP), School of Dentistry, Araraquara, SP, Brazil. 2 University of Florida College of Dentistry, Director, Pain Clinical Research Unit, UF CTSI, Deputy Director, South Atlantic Region, Dental Practice-based Research Network. Clinical and Translational Research Building (CTRB), Gainesville, FL, USA. 3 Department of Clinical & Community Sciences, School of Dentistry, University of Alabama at Birmingham, Birmingham, AL, USA. 4 University of Florida, College of Dentistry, Gainesville, FL, USA. Corresponding author: Elaine Pereira da Silva Tagliaferro School of Dentistry, Araraquara, São Paulo State University (UNESP) Rua Humaitá, 1680 - Centro 14801-903 - Araraquara, SP, Brasil Tel: +55 16 3301-6343 FAX: +55 16 3301-6343 elaine.tagliaferro@unesp.br Received: August 14, 2019 Accepted: January 24, 2020 Methods for caries prevention in adults among dentists from a brazilian community Elaine Pereira da Silva Tagliaferro1,*, Silvio Rocha Correa da Silva1, Fernanda Lopez Rosell1, Aylton Valsecki Junior1, Joseph L. Riley III2, Gregg H. Gilbert3, Valeria Veiga Gordan4 Little is known about dental practice patterns of caries prevention in adults among Brazilian dentists. Aim: To quantify procedures used for caries prevention for adult patients among dentists from a Brazilian community. Methods: Dentists (n=197) who reported that at least 10% of their patients are more than 18 years old participated in the first Brazilian study that used a translated version of the “Assessment of Caries Diagnosis and Caries Treatment” from the U.S. National Dental Practice-Based Research Network. A questionnaire about characteristics of their practice and patient population were also completed by the dentists. Generalized linear regression models and a hierarchal clustering procedure were used (p<0.05). Results: In-office fluoride application was the preventive method most often reported. The main predictors for recommending some preventive agent were: female dentist (dental sealant; in-office fluoride; non-prescription fluoride) and percentage of patients interested in caries prevention (dental sealant; in-office fluoride; non-prescription fluoride). Other predictors included private practice (dental sealant), percentage of patients 65 years or older (in-office fluoride), graduation from a private dental school (non-prescription fluoride), years since dental school graduation (chlorhexidine rinse) and using a preventive method (recommending sealant/fluoride/chlorhexidine rinse/sugarless, xylitol gum). Cluster analysis showed that dentists in the largest subgroup seldom used any of the preventive agents. Conclusion: Dentists most often reported in-office fluoride as a method for caries prevention in adults. Some practitioner, practice and patients’ characteristics were positively associated with more- frequent use of a preventive agent. Keywords: Dental caries. Practice Patterns, Physicians. Preventive dentistry. 2 Tagliaferro et al. Introduction Caries prevalence in adults is high worldwide. More than 90% of adults experience caries at some point in their lifetimes1-4. Mean DMFT scores for 35- to 44-year-old adults ranged from 6.6 to 17.6 among twenty-three European countries3 and is 16.75 among Brazilian adults, according to the last national epidemiological survey1. A recent report estimated that about 25 percent of adults in the U.S. had untreated caries5. Treatment needs were reported by 75% and 47% of Brazilian adults and elderly, respectively1. These findings may be related to the fact that dental caries prevention efforts historically have focused on children rather than adults6. A major increase in the focus of public health efforts in adults should be on those who are transitioning into higher caries risk status7. Therefore, dentists and dental health managers should direct efforts to improve adults’ oral health and research should assess the oral health status as well as which preventive strategies the adult population is receiving from their dentists. Members of the Dental Practice-Based Research Network (Dental PBRN) from the United States, Denmark, Norway, and Sweden reported applying in-office fluoride on 37% of their adult patients8. A minority (21%) of dentists in the Japan Dental PBRN rec- ommended in-office fluoride application to most of their patients over 18 years old9. The most-frequent users of caries prevention were recently-graduated dentists, those who perform caries risk assessment or who practice individualized caries prevention8. Japanese dentists whose patients are interested in caries prevention or those who believe in the effectiveness of caries risk assessment were more likely to recommend in-office fluoride to 50% or more of their patients9. Dentists from the Brazilian community of Araraquara, São Paulo State, participated in the first Brazilian study to use the same questionnaire (after translation and cultural adaptation) used in the U.S. and Japanese studies described above to assess dental preventive practices. The current study aims to quantify procedures used for caries prevention for adult patients among these Brazilian dentists. MATERIAL AND METHODS Study design This research is part of a major cross-sectional study that was performed to assess dental practices related to diagnosis and treatment of dental caries by means of two paper questionnaires: (1) one about characteristics of their practice and patient popu- lation; and (2) a translated version of the “Assessment of Caries Diagnosis and Caries Treatment” from the U.S National Dental Practice-Based Research Network. In the pres- ent paper, we present the results from the caries prevention section of the questionnaire. Ethical aspects The major cross-sectional study was reviewed and approved by the Institutional Review Board (Research Ethics Committee; protocol number #78/11). All participants provided informed consent prior to participation in the study. 3 Tagliaferro et al. Participants and Data Collection Questionnaires were sent by mail to 801 dentists for whom we had address/contact information. During study planning, we received a list of 722 dentists registered at the Regional Council of Dentistry of São Paulo State – Araraquara region, in 2011. Because data were collected in 2014-2015, we updated the list by consulting inter- net sources, which increased the list to 801 dentists. After using several strategies to increase the response rate (pre-paid return envelope, questionnaires sent to work address; a second copy of the questionnaire to non-respondents; precontact by tele- phone; collection of completed questionnaires at work address)10, a total of 217 den- tists who met all inclusion criteria (currently practices in Araraquara, treats dental car- ies; not retired; and provided signed informed consent) participated in the major study, providing an overall response rate of 27% (217/801). In the present paper, participants were 197 dentists among the 217 dentists who reported that at least 10% of their patients are more than 18 years of age. Measures Participant dentists received two paper questionnaires: (1) one about demographic data and information about their clinical training and individual practices and (2) a translated version of the “Assessment of Caries Diagnosis and Caries Treatment” from the U.S National Dental Practice-Based Research Network. The Brazilian version of the questionnaire was produced by conducting the following steps: initial transla- tion, back-translation, committee review11 and pre-testing, during which comprehen- sion of questions was tested with 21 dentists and test-retest reliability was estimated with 17 dentists, with a mean time between test and retest of seven days. Results from this process showed the Intraclass Correlation Coefficients (ICC) as follows: 22 (42%) questions with satisfactory correlation (0.40≤ICC<0.75) and 31 (58%) with excellent correlation (ICC≥0.75), according to Szklo and Nieto12 (2000). Considering that the translated questionnaire does not measure psychometric data and had been previously validated13, no additional validation was needed. Detailed information on the process is published elsewhere10. Table 1 presents the series of questions asked about the use of caries preventive agents in adult patients as well as questions about caries diagnosis, caries risk assessment, and individualized caries preventive treatment regimen. Statistical analyses Descriptive statistics were calculated for all study variables. When reporting ordinal variables representing the percentage of patients receiving caries-related procedures and prevention, ordinal responses are presented as the 25Th, 50th (median) and 75th percentile. In addition, these ordinal data were transformed to the average of each end- point for each category as follows: 0%=0%, 1-24%=12.5%, 25-49%=37%, 50-74%=62%, 75-99%=87%, 100%=100%. The distance between ordinal categories, although not equal, can be estimated in this way with moderate precision. Consequently, we believe the data transformed to percentages in this manner for presentation in the tables can aid readers in interpretation. 4 Tagliaferro et al. Next, practitioner and practice characteristics were tested as predictors of use for each caries prevention agent for adult patients using generalized linear models and an ordi- nal response model. These variables included dentist gender (male=0 and female=1), years since dental school graduation, whether the dental school from which the den- tist graduated was private or public (public=0 and private=1), completed specialization training (general dentistry=0 and specialization=1), an advanced degree (no advanced degree=0, master’s or doctorate=1), percentage of patients who are 65 years of age or older, the dentist’s practice is exclusively a private practice model (public health or hybrid private/public health models=0, private=1). Practitioner and practice characteris- tics that were significant at p<0.10 were included in the first step of subsequent model testing for each individual caries prevention agent. Next, these items were included in a second step: caries-related practice patterns; percent of patients for whom a dental explorer is used to diagnose an occlusal caries lesion; whether caries risk was assessed (not performing caries risk assessment=0 and performing caries risk assessment=1); and percentage of patients who desire individualized caries prevention and who receive an individualized caries prevention regimen. In the final step, frequencies of the other preventive agents were entered to test for associations between use of agents. A back- ward elimination approach was used for step two and three that removed the least-sig- nificant variable from the model in subsequent steps until all remaining variables were significant using p<0.10 for retention14. The change in the chi-square (x2) statistic as well as the differences in degrees of freedom (x2diff = x 2 s - x 2 1 and dfdiff = dfs - df1 where s denotes the “smaller” model with less parameters) were used to test for significance and reflects the improvement in prediction following each step15. To identify subgroups of dentists with a similar preventive orientation, a hierarchal cluster- ing procedure was used. The sugarless or xylitol gum variable was not included as it was Table 1. Questions asked about caries prevention, assessment, caries risk assessment, and individualized preventive treatment. Instructions: Of patients more than 18 years old, for what percentage do you: Caries prevention Apply dental sealants on the occlusal surface of at least one of their permanent teeth? Administer an in-office fluoride application, such as fluoride gel, fluoride varnish, or fluoride rinse? Recommend a non-prescription (over-the-counter) fluoride rinse? Provide a prescription for some form of fluoride? Recommend an at-home regimen of Chlorhexidine rinse? Recommend sugarless chewing gum or xylitol chewing gum? Caries assessment, risk assessment, individualized preventive treatment When you examine patients to determine if they have a primary occlusal caries lesion, on what percent of these patients do you use a dental explorer to diagnose the lesion? Do you assess caries risk for individual patients in any way? Do you use a special form for caries risk assessment? What percent of patients in your practice are interested enough in caries prevention to justify you recommending to them an individualized caries preventive regimen? For what percent of patients do you give individualized preventive treatment specifically for their needs? Participants had the following answering choices: 1 – Never or 0% 2 – 1 to 24% 3 – 25 to 49% 4 – 50 to 74% 5 – 75 to 99% 6 – Every time or 100% 5 Tagliaferro et al. considered an adjunctive rather than a primary prevention agent. Ward’s clustering method with squared Euclidean distances as the similarity measure was chosen in order to be sen- sitive to differences in elevation as well as profile shape16. Dentist and practice characteris- tics were tested for differences across the preventive clusters using ANOVA or chi-square as appropriate. Pair-wise comparisons were performed using a Bonferroni correction. RESULTS Table 2 shows the practitioner and practice characteristics for eligible dentists. Most of them were females (59%), working in a private hybrid (private + public) model (78%), graduated from a public institution (77%), and had received specialty training (63%). Table 3 summarizes the frequency of use of each caries prevention agent for adult patients. In-office fluoride application was the preventive method most reported by dentists for caries prevention in adults. Table 4 shows results of the generalized linear regression modeling, specifically the statistical significance at each step in the analysis and the parameter estimates for the predictors of the frequency of use of each caries prevention agent. Dental sealants. Female dentists and those in private practice apply dental sealants to a higher percentage of adult patients compared to dentists in other practice models (p=0.001) and male dentists (p=0.044). In step 2, dentists who have a greater percentage of patients interested in a caries prevention regimen apply dental sealants to a significantly higher percentage of adult patients (p=0.048). In step 3, dentists who apply dental seal- ants to a higher percentage of adult patients are also more likely to administer an in-office fluoride (p=0.042) and recommend sugarless/xylitol gum (p=0.012) more often to their adult patients. The overall model was a good fit for the data [x2 (5) = 21.645, p=0.001]. In-office fluoride. Female dentists administer an in-office fluoride application to a higher percentage of adult patients compared to male dentists (p=0.014). In addition, dentists with a higher percentage of patients who are 65 years of age or older were more likely to use in-office fluoride (p=0.042). In step 2, dentists who have a greater percentage of patients interested in a caries prevention regimen are more likely to administer an in-office fluoride to their adult patients (p=0.009). In step 3, dentists who more frequently administer an in-office fluoride to their adult patients are also more likely to apply dental sealants (p=0.006) and recommend a non-prescription fluoride (p=0.001). The overall model was a good fit for the data [x2 (6) = 26.972, p<0.001]. Non-prescription fluoride. Female dentists recommend an over-the-counter (OTC) fluo- ride rinse to a higher percentage of adult patients compared to male dentists (p=0.009). Dentists who graduated from a private dental school recommend an OTC fluoride rinse to a larger percentage of their adult patients than dentists who graduated from a public dental school (p=0.017). In step 2, dentists who have a greater percentage of patients interested in a caries prevention regimen (p=0.012) are more likely to administer an OTC fluoride to their adult patients compared to dentists who have a smaller percentage of patients interested in a caries prevention regimen. In step 3, dentists who are more likely to recommend an OTC fluoride rinse are significantly more likely to apply in in-office flu- oride (p<0.001) and recommend an at-home regimen of chlorhexidine rinse (p<0.001). The overall model was a good fit for the data [x2 (6) = 35.518, p<0.001]. 6 Tagliaferro et al. Prescription fluoride. In step 3, dentists who more frequently provide a prescription for some form of fluoride are significantly more likely to apply in in-office fluoride (p=0.042) and recommend an at-home regimen of chlorhexidine rinse (p=0.012). The overall model was a good fit for the data [x2 (2) = 9.484, p=0.009]. Table 2. Dentist’s and practice’s characteristics Characteristic Percentage (n) Mean (SD) Mean % ∆, Percentiles (25th, 50th, 75th) ф Age of dentist 42.2 (SD=11.4) Gender of dentist (female) 59% (n=116) Type of practice Private practice 50% (n=98) Private/public hybrid 28% (n=55) Public health 17% (n=34) Other 5% (n=10) Years since dental school graduation 19.7 (SD=11.1) Type of dental school from which the dentist graduated Public institution 77% (n=151) Private institution 23% (n=46) Specialization Not completed specialization training 37% (n=72) Specialization training 63% (n=125) Advanced degree No advanced degree 70% (n=138) Master’s degree 6% (n=11) PhD degree 25% (n=48) Percent of patients by age cohort Pediatric patients (1-18 years) 19% (SD=19) Adults (19-44 years) 36% (SD=17) Adults (45-64 years) 32% (SD=16) Adults (65 years or older) 13% (SD=10) Percent of patients a dental explorer is used to diagnose an occlusal caries lesion? 65% 2, 5, 6 Assess caries risk for individual patients 34% (n=63) ¥ Use a special form for caries risk assessment (of the 63 who perform caries risk assessment) 38% (n=24) Percent of patients who are interested in a caries prevention regimen 44% 2, 4, 4 Percent of patients who receive a caries risk prevention regimen 54% 2, 4, 5 ∆ Percentage when the ordinal values were transformed as follows to category median: 0%=0%, 1-24%=12.5%, 25-49%=37%, 50-74%=62%, 75-99%=87%, 100%=100% ф 25Th, 50th (median) and 75th percentile for ordinal categories scaled as 1 – Never or 0%, 2 – 1 to 24%, 3 – 25 to 49%, 4 – 50 to 74%, 5 – 75 to 99%, 6 – Every time or 100% ¥ Nine practitioners did not indicate whether they assess for caries risk 7 Tagliaferro et al. Chlorhexidine rinse. Dentists who had more years since graduation from dental school were less likely to recommend an at-home regimen of chlorhexidine rinse (p=0.016). In step 3, dentists who are more likely to recommend an at-home regi- men of chlorhexidine rinse are also more likely to also recommend an OTC fluoride (p<0.001), provide a prescription for some form of fluoride (p=0.015), and recommend sugarless/xylitol gum (p<0.001) to their adult patients. The overall model was a good fit for the data [x2 (5) = 46.467, p<0.001]. Sugarless or Xylitol gum. In step 3, dentists who more frequently recommend sug- arless/xylitol gum are significantly more likely to apply dental sealants (p=0.001) and recommend an at-home regimen of chlorhexidine rinse (p=0.001) to their adult patients. The overall model was a good fit for the data [x2 (2) = 31.862, p<0.001]. Dentists grouped by preventive profile Inspection of the agglomeration coefficients from the cluster analysis showed that the percentage increase between the four-cluster and the three-cluster solutions was nearly twice the increase for the preceding steps. This suggests that the final four clusters are sufficiently dissimilar and that the four-cluster solution is the most appro- priate16. Means and SD for the six caries prevention agents for each of the three-clus- ter subgroups are presented in Table 5. Dentists in the largest subgroup (n=99) seldom used any of the preventive agents and we labeled this group as “infrequent users of prevention”. Consistent with this, they also had the lowest percentage of patients who receive individual caries prevention (46% of patients) and lowest percentage of patients who desire individual caries pre- vention (36%). They were also among the subgroups least likely to assess caries risk. This subgroup also contained the lowest percentage of female dentists (51%). These dentists had the lowest percentage of patients 18-44 years of age (34%) and the high- est percentage of patients in the 45-64 age group (35%). Table 3. Mean percent of adult patients within a practice who receive each caries preventive agent. Preventive agent Mean % ∆ (95% CI) € Percentiles (25, 50, 75) ф In-office fluoride 51% (46,56) 2, 3, 6 Chlorhexidine rinse 27% (23,30) 2, 2, 3 Non-prescription fluoride 22% (20,24) 1, 1, 3 Xylitol gum 18% (16,21) 1, 1, 3 Prescription fluoride 15% (14,17) 1, 2, 2 Dental sealant 14% (12,16) 1, 2, 2 ∆ Percentage when the ordinal values were transformed as follows to category median: 0%=0%, 1-24%=12.5%, 25-49%=37%, 50-74%=62%, 75-99%=87%, 100%=100%. € 95% Confidence interval for Mean %. ф 25Th, 50th (median) and 75th percentile for ordinal categories scaled as 1 – Never or 0%, 2 – 1 to 24%, 3 – 25 to 49%, 4 – 50 to 74%, 5 – 75 to 99%, 6 – Every time or 100% 8 Tagliaferro et al. The second largest group (n=38 dentists) consistently applied in-office fluoride (91%) and made frequent recommendations for an OTC fluoride rinse (76%). They were also the group most likely to provide a prescription for Chlorhexidine rinse (42%). Overall, they consistently used the full range of preventive agents and we have labeled this subgroup “comprehensive use of prevention”. However, they were among the sub- groups least likely to assess caries risk (27%). This subgroup contained the highest percentage of female dentists (74%). Table 4. Modeling to explain the use of preventive agents among adult patients Preventive agent Final model fit B (SE) P. Value Dental sealant Private practice 0.965 (0.292) 0.001 Dentist gender (female) x2 (2) = 9.354, p=0.008* 0.522 (0.250) 0.044 % patients interested in caries prevention ∆x2 (1) = 3.865, p=0.049** 0.143 (0.706) 0.048 In-office fluoride 0.150 (0.066) 0.042 Sugarless/xylitol gum ∆x2 (2) = 8.426, p=0.013*** 0.219 (0.084) 0.012 In-office fluoride Private practice -0.251 (0.134) 0.056 Dentist gender (female) 0.606 (0.246) 0.014 Patients 65 years of age or older x2 (3) = 8.187, p=0.039* 0.027 (0.012) 0.042 % patients interested in caries prevention ∆x2 (1) = 6.578, p=0.011** 0.255 (0.116) 0.009 Dental sealants 0.347 (0.127) 0.006 Non-prescription fluoride ∆x2 (2) = 12.207, p=0.003*** 0.268 (0.103) 0.001 Non-prescription fluoride Dentist gender (female) 0.571 (0.207) 0.009 Patients 65 years of age or older 0.019 (0.011) 0.070 Type of dental school (private) x2 (3) = 13.354, p=0.004* 0.631 (0.264) 0.017 % patients interested in caries prevention ∆x2 (1) = 5.354, p=0.014** 0.212 (0.101) 0.012 In-office fluoride 4.592 (1.179) < 0.001 Chlorhexidine rinse ∆x2 (2) = 18.810, p<0.011*** 6.572 (1.964) < 0.001 Prescription fluoride In-office fluoride 0.99 (0.043) 0.042 Chlorhexidine rinse x2 (2) = 9.484, p=0.009** 0.144 (0.068) 0.012 Chlorhexidine rinse Years since dental school graduation -0.016 (0.007) 0.016 Type of dental school (private) ∆x2 (2) = 10.431, p=0.005* -0.338 (0.197) 0.066 Non-prescription fluoride 0.187 (0.046) <0.001 Prescription fluoride 0.158 (0.065) 0.015 Sugarless/xylitol gum ∆x2 (3) = 36.036, p<0.001*** 0.157 (0.044) <0.001 Sugarless/xylitol gum Dental sealants 0.262 (0.089) 0.001 Chlorhexidine rinse x2 (2) = 31.862, p<0.001**** 0.291 (0.097) 0.001 * Chi-square (x2) for model with practice/practitioner variables ** ∆x2 for model with step 2 variables (caries-related practice patterns) added *** ∆x2 for model with step 3 variables (other preventive agents) added **** ∆x2 for model with only step 3 variables (other preventive agents) as no variables were significant in the baseline model or following step 2. 9 Tagliaferro et al. The next group also consisted of 38 dentists; these dentists tend to focus on the use of in-office fluoride (97%) and seldom recommend at-home use of prescription or OTC fluoride. This group was labeled “in-office fluoride preference”. Along with the “in-office sealant and fluoride preference” subgroup discussed below, they were the most likely to assess caries (47%). In addition, they had the highest percentage of patients who desired (53%) and received (68%) individual caries prevention. Table 5. Use of preventive agents for adult patients by preventive subgroups and dentist’s, patient’s, and practice’s characteristics Use of preventive agent Infrequent users of prevention Comprehensive use of prevention In-office fluoride preference In-office sealant and fluoride Caries prevention (n=197) n=99 n=38 n=38 n=22 Dental sealant 4% ∆ (4, 6) € a 1, 1, 2 ф 24% (19,30) b 1, 1, 4 7% (5,9) a 1, 1, 2 51% (44,59) c 2, 4, 5 In-office fluoride 20% (18,22) a 2, 2, 3 91% (88,94) b 5, 5, 6 97% (96,98) b 6, 6, 6; 48% (41,56) c 2, 3, 5 Non-prescription fluoride 12% (10,14) a 1, 1, 2 76% (72, 81) b 4, 5, 6 3% (0,6) a 1, 1, 1 7% (4,11) a 1, 1, 2 Prescription fluoride 9% (8,11) a 1, 1, 2 24% (19,29) b 1, 2, 3 10% (7,12) a 1, 1, 2 33% (26,41) c 1, 2, 4 Chlorhexidine rinse 23% (21,25) a 2, 2, 3 42% (37,48) b 2, 3, 4 27% (23,31) a 2, 2, 3 22% (18,26) a 1, 2, 3 Sugarless/xylitol gum 14% (11,18) 1, 1, 2 21% (14,27) 1, 1, 3 21% (14,27) 1, 1, 2 17% (9,25) 1, 1, 2 Practice characteristics Dentist gender (females) 51% a 74% b 60% 59% Type of practice (private) 52% 47% 38% a 75% b Years since dental school graduation 19.9 (SD=12) 18.5 (SD=9) 19.7 (SD=11) 20.3 (SD=11) Type of dental school from which the dentist graduated (public institution) 79% 68% 87% 76% Specialization (specialization training) 60% 68% 68% 60% Advanced degree (Master’s or doctorate) 31% 24% 30% 40% Percent of patients by age cohort Pediatric patients 18% 16% 24% 20% Adults (19-44 years) 34% a 35% 38% 45% b Adults (45-64 years) 35% a 34% 25% b 25% b Adults (65 years and older) 13% 15% 13% 9% Assess caries risk for individual patients 29% a 27% a 47% b 42% b Patients who desire individual caries prevention (%) 36% b 2, 3, 4 51% a 3, 4, 4 53% a 3, 3, 4 49% a 3, 4, 4 Patients who receive individual caries prevention (%) 46% a 2, 3, 5 55% 2, 4, 5; 68% b 3, 5, 6 60% 3, 4, 5 Groups with different superscripts are different using a Bonferroni correction (p=0.01) for that variable and groups without superscripts or that share superscripts are not significantly different. Subgroups did not differ on other practice characteristics. ∆ Percentage when the ordinal values were transformed as follows to category median: 0%=0%, 1-24%=12.5%, 25-49%=37%, 50-74%=62%, 75-99%=87%, 100%=100%. € 95% Confidence interval for Mean %. ф 25Th, 50th (median) and 75th percentile for ordinal categories scaled as 1 – Never or 0%, 2 – 1 to 24%, 3 – 25 to 49%, 4 – 50 to 74%, 5 – 75 to 99%, 6 – Every time or 100% 10 Tagliaferro et al. The final group was the smallest (n=22) and had the most frequent use of dental sealants (51%) and in-office fluoride (47%). They were also the ones most likely to rec- ommend fluoride prescription. This group was labeled “in-office sealant and fluoride preference” and had the higher percentage of practitioners using a private practice model. Along with the “in-office fluoride preference” subgroup discussed above, they were the most likely to assess caries risk in their patients (42%). DISCUSSION To our knowledge this current work is the first report in the literature about caries prevention in adults by Brazilian dentists as assessed using the translated version of the “Assessment of Caries Diagnosis and Caries Treatment” Questionnaire from the Practice-Based Research Network in the United States of America. Dentists participating in this study were primarily middle-aged (42.2 years) females (59%), working in a private hybrid (private + public) model (78%), graduated from a pub- lic institution (77%), and had received specialty training (63%). Demographic data from the Regional Council of Dentistry of São Paulo State showed that 57% of dentists from Araraquara were female and 66% were younger than 50 years of age17. National data show that most Brazilian dentists are female (51.2%), are up to 40 years-old (57.4%), graduated from private schools (65.0%) and had no specialty training (75%)18. Therefore, in spite of using a convenience sample, demographic data from participant dentists were quite similar to dentists from Araraquara and a lesser extent to Brazilian dentists. Dentists in the current study reported that in-office fluoride application was the pre- ventive method most commonly used (51% of patients) for caries prevention in adults. Participating dentists also reported recommending non-prescription fluoride to 22% of their adult patients (Table 3). Dentists from Japanese9 and US8 dental PBRNs recommended in-office fluoride application to 21% and 37% of their adult patients, respectively. Brazilian dentists reported recommending in-office fluoride at more than twice the rate of Japanese dentists. Yokoyama et al.9 (2016) mentioned that the focus of the current Japanese health insurance system is disease treatment and that it does not cover most preventive dental care services. As a result, the percentage of Japa- nese dentists providing preventive treatment may be reduced9. Brazilian oral health insurance system and public service offer several preventive measures, including in-office fluoride application. Taking into account that 98% of dentists in the current study reported working in a private and/or public health service, and that participant dentists believe that 44% of their adult patients are interested in a caries prevention regimen, their first choice for caries prevention dentists was in-office fluoride appli- cation, which was significantly higher than those reported by dentists from the Japa- nese and US dental PBRNs. Chlorhexidine rinse was also reported frequently by Brazilian dentists as a caries pre- ventive agent for their adult patients (Table 3). Scientific evidence for chlorhexidine as a caries preventive agent is not consensual. Some authors found statistically signif- icant differences in Streptococcus mutans levels during and after the use of a chlor- hexidine mouthwash on patients with moderate to high caries risk. However, they suggested the need for additional studies in order to assess whether the results con- 11 Tagliaferro et al. firm the reduction in dental caries and, consequently, whether or not these products should be incorporated into existing prevention protocols19. Others studies have not found good evidence of the effectiveness of chlorhexidine for caries prevention20,21. Results from our regression analyses suggest that the main predictor for recommend- ing in-office fluoride application or other preventive methods was dentist gender, with females recommending more often than male dentists (Table 4). These findings are in agreement with those of Riley et al.22 (2011), who found that female dentists had a greater overall preventive orientation than male dentists for both adult and pediatric patients. However, the scientific literature is not consensual about gender differences on attitudes on prevention and treatment of dental caries. Some researchers have found a more-conservative approach towards prevention and treatment of dental car- ies among female dentists23-26. In contrast, other studies have found no statistically significant relationship between dentist gender and choices for caries prevention or treatment27-29. A previous Brazilian study has also found no association between den- tists’ gender and decision making for restoring dental caries as seen in radiographs30. Further studies are needed to clarify this issue. Other predictors for recommending some type of preventive method showed that patients 65 years of age or older are more likely to receive in-office fluoride (Table 4). This finding could be related to dentists being concerned with the prevention of root caries. Root caries is most commonly found in the elderly population, with four out of ten adults being affected31. Brazilian elderly presented a mean DMFT of 27.5, with a mean of 0.2 decayed roots and 0.1 filled roots1. The overall prevalence of root caries was estimated at 41.5% in a systematic review and meta-analysis published by Pen- tapati et al.31 (2019). The authors related that the number of adults with root caries might expand in the future because of the increase in aging population and dentition longevity, and suggested that preventive measures should be the focus of policy-mak- ers and health care professionals to reduce the burden of disease among the elderly. It is relevant to emphasize that the percentage of patients interested in caries preven- tion may be predictive of dentists being more likely to provide dental sealants, in-office fluoride application or non-prescription fluoride to their adult patients. Although there is lack of literature supporting the cost-effectiveness of use of fluorides and sealants for caries prevention in adult patients32, one can speculate that patient interest in car- ies prevention may stimulate dentists to adopt a more-preventive approach, perhaps influenced more strongly by the patients’ interest than by the patients´ caries risk. In the current study only 34% of dentists assessed caries risk for individual patients (Table 1). Another possible explanation is that dentists are working in a person-cen- tered care environment, employing the principles of shared decision-making33 in which the patient can act as a partner who co-designs his/her care delivery34. Further studies are needed to assess these assumptions. Modern caries management emphasizes a conservative and preventive evi- dence-based philosophy, with personalized disease management, monitoring of car- ies lesions, and efforts to remineralize and/or arrest lesions32. As we consider the above-mentioned evidence in caries prevention, it is worth discussing the results of cluster analysis that showed a clear agglomeration of dentists in the largest sub- group (n=99) characterized by infrequent use of prevention and associated with the 12 Tagliaferro et al. following profile: 1) lowest percentage of patients who receive or desire individual caries prevention, 2) least likely to assess caries risk, 3) lowest percentage of female dentists, and 4) the highest percentage of patients in the 45-64 age group (Table 5). The results of the current study showed a gap between evidence-based dentistry and dental practice for half of participating dentists. Although there are limitations asso- ciated with the study, it clearly indicates that additional means to translate current evidence-based findings for caries prevention into clinical practice is needed and it may be targeted to the above-mentioned practice characteristics. This study did have these limitations: a) we cannot infer causality from a cross-sec- tional design; b) it used a convenience sample and singular characteristics of the region (access to a dental school, preventive practices taught in the region, etc.) may have strongly influenced the results; c) the assumption that the reported overall pre- ventive measures are actually what the responding dentists perform routinely and not related to individual patient recommendations for single or multiple treatments22; and that they may be influenced by social desirability and recall bias8. The study strengths include the similarity of the demographic characteristics between the participating dentists and those from Araraquara, and the feasibility of the questionnaire to assess and to compare dental practice patterns among dentist populations35. In conclusion, in-office fluoride application was the most commonly reported preventive method for caries prevention in adults. Some practitioner, practice and patients’ charac- teristics were positively associated with more-frequent use of a preventive agent. Acknowledgements Financial support was provided by the Foundation for the Development of the São Paulo State University (FUNDUNESP; Grant 0170/004/13-PROPe/CDC) and by The São Paulo Research Foundation (FAPESP; Grant 2012/10397-2). Certain components of this work were supported by National Institutes of Health grants U01- DE-16746, U01-DE-16747, U19-DE-22516, and U19-DE-28717. Opinions and assertions contained herein are those of the authors and are not to be construed as necessarily representing the views of the respective organizations or of the National Institutes of Health. NIDCR had no role in the study design, data collection and analysis, decision to publish, or preparation of the manuscript. The authors thank Claudia Huck, Fabiano Jeremias, Juliana Alvares Duarte Bonini Campos, Mariana de Matos, Luana Moreira Loures Ridolfi, Wilson Chediek, Elina Mara da Silva Marcomini, Rita De Cassia Prando, Márcia Santana, Luis Alberto da Silva, Ivanete Correa Macieira, Célia Regina de Freitas Rocha, Olavo Bergamaschi Barros and Karina Antunes for their assistance and dentists who participated in this study. References 1. SB Brazil 2010: [National Research on Oral Health: main results]. Brasília, 2012 [cited 2019 Apr 15]. Available from: http://bvsms.saude.gov.br/bvs/publicacoes/pesquisa_nacional_saude_bucal.pdf. Portuguese. 2. Xu W, Lu HX, Li CR, Zeng XL. Dental caries status and risk indicators of dental caries among middle-aged adults in Shanghai, China. J Dent Sci. 2013;9(2):151-7. doi: 10.1016/j.jds.2013.05.002. http://bvsms.saude.gov.br/bvs/publicacoes/pesquisa_nacional_saude_bucal.pdf 13 Tagliaferro et al. 3. Carvalho JC, Schiffner U. Dental caries in European adults and senior citizens 1996-2016: ORCA Saturday Afternoon Symposium in Greifswald, Germany - Part II. Caries Res. 2019;53(3):242-52. doi: 10.1159/000492676. 4. Dye BA, Thornton-Evans G, Li X, Iafolla TJ. Dental caries and tooth loss in adults in the United States, 2011–2012. NCHS Data Brief. 2015 May;(197):197. 5. Gupta N, Vujicic M, Yarbrough C, Harrison B. Disparities in untreated caries among children and adults in the U.S., 2011-2014. BMC Oral Health. 2018 Mar 6;18(1):30. doi: 10.1186/s12903-018-0493-7. 6. Bader JD, Vollmer WM, Shugars DA, Gilbert GH, Amaechi BT, Brown JP, et al. Results from the xylitol for adult caries trial (X-ACT). J Am Dent Assoc. 2013 Jan;144(1):21-30. 7. Horst JA, Tanzer JM, Milgrom PM. Fluorides and other preventive strategies for tooth decay. Dent Clin North Am. 2018 Apr;62(2):207-234. doi: 10.1016/j.cden.2017.11.003. 8. Riley JL 3rd, Gordan VV, Rindal DB, Fellows JL, Ajmo CT, Amundson C, et al. Preferences for caries prevention agents in adult patients: findings from the dental practice-based research network. Community Dent Oral Epidemiol. 2010 Aug;38(4):360-70. doi: 10.1111/j.1600-0528.2010.00547.x. 9. Yokoyama Y, Kakudate N, Sumida F, Matsumoto Y, Gilbert GH, Gordan VV. Evidence-practice gap for in-office fluoride application in a dental practice-based research network. J Public Health Dent. 2016 Mar;76(2):91-7. doi: 10.1111/jphd.12114. 10. Tagliaferro EPS, Ridolfi LML, Matos M, Rosell FL, Valsecki Junior A, Silva SRC, et al. [Translation and Brazilian adaptation of the “Assessment of caries diagnosis and caries treatment questionnaire”]. Arq Odontol. 2017;53:e13. doi: 10.7308/aodontol/2017.53.e13. Portuguese. 11. Guillemin F, Bombardier C, Beaton D. Cross-cultural adaptation of health-related quality of life measures: literature review and proposed guidelines. J Clin Epidemiol. 1993 Dec;46(12):1417-32. 12. Szklo M, Nieto FJ. Quality assurance and control. In: Epidemiology beyond the basics. Gaithersburg, Md: Aspen Publications; 2000. 13. Gordan VV, Bader JD, Garvan CW, Richman JS, Qvist V, Fellows JL, et al. Restorative treatment thresholds for occlusal primary caries among dentists in the dental practice-based research network. J Am Dent Assoc. 2010 Feb;141(2):171-84. 14. Menard S. Applied logistic regression. Thousand Oaks: Sage Publications; 1995. 15. Farrington CP. On assessing goodness of fit of generalized linear models to sparse data. J R Statist Soc B. 1996;58(2):349-60. doi: 10.1111/j.2517-6161.1996.tb02086.x. 16. Milligan GA, Cooper MC. An examination of procedures for determining the number of clusters in a data set. Psychometrika 1985 Jun;50(2):159-79. 17. Rocha E. Statistical Data [personal communication]. Message to: EPST, 2015 Mar 20 [cited 2015 Mar 20]. [4 paragraphs].. 18. Morita C, Haddad AE, Araújo ME. [Current profile and trends of Brazilian dentists]. Maringá, PR: Dental Press; 2010. Portuguese. 19. Coelho ASEC, Paula ABP, Carrilho TMP, Silva MJRF, Botelho MFRR, Carrilho EVVF. Chlorhexidine mouthwash as an anticaries agent: a systematic review. Quintessence Int. 2017;48(7):585-591. doi: 10.3290/j.qi.a38353. 20. Rethman MP, Beltrán-Aguilar ED, Billings RJ, Hujoel PP, Katz BP, Milgrom P, et al. Non-fluoride caries-preventive agents: executive summary of evidence-based clinical recommendations. J Am Dent Assoc. 2011 Sep;142(9):1065-1071. 21. Walsh T, Oliveira-Neto JM, Moore D. Chlorhexidine treatment for the prevention of dental caries in children and adolescents. Cochrane Database Syst Rev. 2015 Apr 13;(4):CD008457. doi: 10.1002/14651858.CD008457.pub2. 14 Tagliaferro et al. 22. Riley JL 3rd, Gordan VV, Rouisse KM, McClelland J, Gilbert GH; Dental Practice-Based Research Network Collaborative Group. Differences in male and female dentists’ practice patterns regarding diagnosis and treatment of dental caries: findings from The Dental Practice-Based Research Network. J Am Dent Assoc. 2011 Apr;142(4):429-40. 23. Ghasemi H, Murtomaa H, Torabzadeh H, Vehkalahti MM. Knowledge of and attitudes towards preventive dental care among Iranian dentists. Eur J Dent. 2007 Oct;1(4):222-9. 24. Nagarajappa R, Sanadhya S, Batra M, Daryani H, Ramesh G, Aapaliya P. Perceived barriers to the provision of preventive care among dentists of Udaipur, India. J Clin Exp Dent. 2015 Feb 1;7(1):e74-9. doi: 10.4317/jced.51770. 25. Yusuf H, Tsakos G, Ntouva A, Murphy M, Porter J, Newton T, et al. Differences by age and sex in general dental practitioners’ knowledge, attitudes and behaviours in delivering prevention. Br Dent J. 2015 Sep 25;219(6):E7. doi: 10.1038/sj.bdj.2015.711. 26. Bozorgmehr E, Ansari H, Poordavar M, Dahmardeh Ghalenou A. Survey of preventive services by general dental practitioners in Zahedan, 2016. Dent Clin Exp J. 2016 Feb;2:e10019. doi: 10.5812/dcej.10019. 27. Rechmann P, Doméjean S, Rechmann BM, Kinsel R, Featherstone JD. Approximal and occlusal carious lesions: Restorative treatment decisions by California dentists. J Am Dent Assoc. 2016 May;147(5):328-38. doi: 10.1016/j.adaj.2015.10.006. 28. Staxrud F, Tveit AB, Rukke HV, Kopperud SE. Repair of defective composite restorations. A questionnaire study among dentists in the Public Dental Service in Norway. J Dent. 2016 Sep;52:50-4. doi: 10.1016/j.jdent.2016.07.004. 29. Rønneberg A, Skaare AB, Hofmann B, Espelid I. Variation in caries treatment proposals among dentists in Norway: the best interest of the child. Eur Arch Paediatr Dent. 2017 Oct;18(5):345-353. doi: 10.1007/s40368-017-0298-4. 30. Traebert J, Wesolowski CI, Lacerda JT, Marcenes W. Thresholds of restorative decision in dental caries treatment among dentists from small Brazilian cities. Oral Health Prev Dent. 2007;5(2):131-5. 31. Pentapati KC, Siddiq H, Yeturu SK. Global and regional estimates of the prevalence of root caries - Systematic review and meta-analysis. Saudi Dent J. 2019 Jan;31(1):3-15. doi: 10.1016/j.sdentj.2018.11.008. 32. Fontana M, Gonzalez-Cabezas C. Evidence-based dentistry caries risk assessment and disease management. Dent Clin North Am. 2019 Jan;63(1):119-128. doi: 10.1016/j.cden.2018.08.007. 33. Slayton RL, Fontana M, Young D, Tinanoff N, Nový B, Lipman RD, et al. Dental caries management in children and adults. Discussion Paper. Washington: National Academy of Medicine; 2016 Sep 14. doi: 10.31478/201609d. 34. Lee H, Chalmers NI, Brow A, Boynes S, Monopoli M, Doherty M, et al. Person-centered care model in dentistry. BMC Oral Health. 2018 Nov 29;18(1):198. doi: 10.1186/s12903-018-0661-9. 35. Tagliaferro EPS, Valsecki Junior A, Rosell FL, Silva SRC, Riley JL, Gilbert GH, et al. Caries diagnosis in dental practices: results from dentists in a Brazilian community. Oper Dent. 2019 Jan/Feb;44(1):E23-E31. doi: 10.2341/18-034-C.