Dental caries in children assisted on a dental school clinic: prevalence and associated factors

OBJECTIVE: This study aimed to determine the factors associated with dental caries on primary and permanent dentition of a pediatric dental school clinic users. METHODS: A retrospective study of information collected from 313 dental records obtained from 2011 to 2013. The prevalence of tooth decay on primary (dmft) and permanent dentition (DMFT). Sociodemographic factors, dietary and hygiene habits were analyzed, as well Data were analyzed using Chi-square or Fisher exact test (α = 0.05). RESULTS: Average dmft was 3.47 ± 3.78 and 3.46 ± 3.05 for 0-6 and 7-9 range age, respectively (p = 0.781). Average DMFT was 0.80 ± 1.25 and 3.16 ± 3.72 for the range of 7-9 and ≥ 10 years, respectively (p = 0.00). The restorative treatment need due to dental caries was highly prevalent (78% of dmft and 54% of DMFT). Dmft was associated with paternal education (OR: 0.37, 95% CI: 0.13-1.05) and OHI-S (OR: 2.39, 95% CI: 1.22-4.66). DMFT was associated with gender (OR: 2.36, 95% CI: 1.38-4.01). CONCLUSION: Children assisted in this dental school clinic had a high prevalence of untreated dental caries, mainly associated with paternal education and OHI-S (primary dentition), and gender (permanent dentition).


INTRODUCTION
The epidemiological reduction of caries incidence in the last years is a tendency around the world [1,2,3].However, the dental caries is still a critical issue in public health because it is highly prevalent in specific groups of the population and demands many costs for health services [4,5,6].From the community perspective, dental caries had demonstrated multiple manifestations that demand special attention, mainly due to its psychosocial and functional consequences [4], especially in early ages.
In this framework, understanding the distribution of caries is necessary to improve dental services and planning oral health strategies [7,8].Therefore, epidemiological studies have evaluated the factors influencing the dental caries prevalence in children [9,10,11].These studies are important to understand this disease in the public health context, promoting movement of rational intervention at both community and individual levels.In this context, it is clear that public health services should have different dynamics considering some environmental, cultural and local factors that may influence the working process and the decision making of professionals [12].
Currently, the Unified Health System in Brazil has widely distributed Family Health Unities that promotes dental assistance in primary and secondary levels [13].These services are established by Smiling Brazil policy approved in 2004.This policy also recognize that dental students must have access to an integral formation that considers all the aspects related to oral health diseases [14].Thus, public dental schools clinics are an environment that promotes to the population a large variability of health services and provide a great contact between dental students and the community [15].
The services offered by public universities are commonly unpaid, have a good acceptability and are known as a reference service to the community.Therefore, these services are sought by patients with a diverse and complex treatment needs, which demand high versatility of management strategies and preventive tools [15,16].Consequently, it is necessary to update information regarding the population's profile, as well as their characteristics and oral health necessities.Thus, this study aimed to determine the factors associated with dental caries on primary and permanent dentition of public pediatric dental clinic user., investigating sociodemographic factors an.dietary and oral hygiene habits.

METHODS
After approval of the local ethics committee (Health Science School -Paraíba Federal University.protocol 0186/2014), a retrospective study was carried out based on the analysis of dental records from the Cariology Clinic of Federal University of Paraiba (UFPB).
Three hundred and thirteen (313) records were selected from the population assisted from 2010 to 2013.Data were collected systematically considering demographic (Gender and Age), socioeconomic (Household Income and Paternal Education), dietary habits (Frequency and Type of Diet), hygiene habits (Frequency of Toothbrushing, Sulcus Bleeding Index -SBI and Simplified Oral Hygiene Index -OHI-S) -Box 1. Oral examinations were performed to estimate the dental caries experience on primary (dmft) and permanent (DMFT) according to WHO guidelines [8].
Data were analyzed using SPSS Statistics for Windows version 13.0 (SPSS, Inc., Chicago, IL, USA).The Chi-square (c 2 ) and Fisher's exact tests were carried out to test the association between variables, as well the odds ratio (OR).The significance level was set at p < 0.05 (two-tailed).

RESULTS
The most common age group was 0-6 years (42.9%),followed by 10-16 years (31.4%) and 7-9 years (25.6%).The gender proportion was 1:1.The demand of restorative treatment was highly prevalent, demonstrating a proportion of 0.78 and 0.53 of dmft and DMFT index, respectively.The need for tooth extraction was found in merely 0.06 and 0.03 of the sample.
Table 1 demonstrated that there was no difference between dmft in 0-6 and 7-9 groups (p = 0.781).A significant difference was found between DMFT in 7-9 and ≥ 10 age range (p = 0.000).There was a significant association between dmft and paternal education, as well as dmft and OHI-S (Table 2).DMFT was associated with gender (Table 3).

DISCUSSION
Dental records analyzed in this research demonstrated a reality of individuals who are economically vulnerable and that have high experience of dental caries.This tendency highlighted the necessity of tools development for identifying environmental and social needs beyond the dental needs.
Children who attended this public clinic have high necessity of dental treatment, presented expressive scores of "decayed" component.This result demonstrated the lack of health care access to these children.Many factors contribute to the absence of dental care access to low-income children.These factors might be the socioeconomic and psychological status of parents, difficulties in booking a consultation or transportation, fear of the dentist, and oral health myths [17,18].In this sense, more important than use this information to preview and planning the health services in dental clinic schools is to understand this reality as a peculiar one, that demands a better comprehension by professors and students [18,19,20,21].
Socioeconomic status was not associated with DMFT and dmft.These outcomes are important because prove that little improvement in educational qualification and household income did not reduce significantly the disease prevalence.In this context, it is prudent to notice that in this study the volunteers mostly had low household incomes (below three minimum wages) and schooling (until high school).Some studies have considered the individual contribution of socioeconomic context or the development of dental caries in children [22,23].These studies found that social status, low paternal education, and low family income provide worst oral health conditions [24,25,26,27,28,29].On the other hand, other studies have demonstrated that these factors cannot be considered a determining factor [30].
Paternal education was a protective factor (OR: 0.37) for dental caries in primary dentition.This results contrast with another author that considered the maternal education as the most important predictor for early childhood caries [26,27].In this sense, this investigation was not able to find any significant difference between maternal education and their effective contribution to dental caries prevalence.These results can be explained by the sample composition that has low level of schooling.Besides, it is difficult to make a more accurate comparison from this variable due to the different perspectives of the learning process and teaching quality.
Dietary habits were not significantly associated with dmft and DMFT.These results can be considered a paradox, considering the etiology of dental caries [30,31,32].Therefore, we considered that these results are consequence of the lack of information regarding the fulfillment of dietary diary.This question could be more accurately assessed if the dentist makes an interview to complement the information of the dietary diary.
The toothbrushing frequency was not associated with DMFT.At this point, it is important to evidence that verbal information about poor habits of hygiene is commonly hidden by the parents [33,34].Clinically, the parameters frequently used to sign poor oral hygiene are OHI-S and SBI [35].However, in our investigation we did not find any association with the prevalence of dental caries.These outcomes possibly indicated that these parameters were not good predictors of dental caries in a sick population who is attended in public pediatric clinics.Similarly, Cascaes et al. [34] suggests that the frequency of brushing alone is not enough to assess oral hygiene in children.Thus, we considered that this tendency can be explained by two important pathways: firstly, it is common that children brush better their teeth before going to dental consultations; secondly, parents and children usually hide information about their daily habits.

CONCLUSION
Children attended in a public dental clinic had a high prevalence of untreated dental caries, mainly associated with paternal education and OHI-S (primary dentition), and gender (permanent dentition).Moreover, our findings highlighted the necessity of developing educational strategies for dental students take effective care of children with social deprivation.

Box 1 .
Theoretical framework of dmft and DMFT Part 1. Socioeconomic and Demographic per day; ≥3 times per day SBI Activity High; Low OHI-S Good; Regular; Poor
Distinct letters are statistically different by Student t-test (p<0.05).

Table 1 .
Dental caries experience in each age group

Table 2 .
Factors associated with dental caries experience in primary dentition MW: Minimum wage (s); * Chi-square or Fisher's exact significant.

Table 3 .
Aspects associated with caries experience in pemanent teeth MW: Minimum wage (s); * Chi-square or Fisher's exact significant.Dental caries in children assisted on a dental school clinic | De Sousa et al.