Dental Caries Prevalence and Oral Health Status among 15-Year- Old Adolescents in Kosovo.

Introduction: Caries has a harmful impact on oral and general health and is a major public health problem among children and adolescents. The objective of present study was to investigate into dental caries, oral hygiene, the frequency of brushing habits and dental visits among 15- year- old adolescents. Material and methods: This cross-sectional study was carried out on a random sample of 323 15- year- old adolescents in different schools and municipalities of Kosovo. Oral clinical examination and self-administered questionnaire were used to obtain information about dental caries and oral health practices. Oral hygiene and caries status in permanent dentition was assessed through the DMFT index and Oral Hygiene Index - Simplified (OHI-S). The level of statistical significance was set at p<0.05.
Results: The total mean of the DMFT index was 3.21 ± 2.193, while component D of the DMFT index dominated in both genders, with slightly higher values in boys compared to girls (2.15±2.092, and 1.91±1.919). The mean OHI-S index of adolescents aged 15 was found to be 1.945±3.926. Over 50% of schoolchildren brush their teeth only once per day and they have visited the dentist only when it was necessary. Irregular tooth-brushing, dental visits and poor oral hygiene index were significantly related to dental caries.
Conclusion: The results of the study showed poor oral health status among 15- year- old adolescents in Kosovo. There is an emergent need for caries-prevention programs focusing on oral health and healthy habits.

Introduction

Dental caries is characterized as a pandemic disease which is still widespread around the world among people, particularly in lower socio-economic classes (). The multifactorial etiology of dental caries includes tooth, bacteria in dental plaque, such as Streptococcus mutans, and a carbohydrate diet. As a consequence of these three main factors, and many other factors, the demineralization of the enamel will be caused, and after a while the dentin will also be affected ().

Generally, there are main differences in dental caries between developed and developing countries. In developed countries, a decrease in dental caries was reported as a result of advanced preventive programs applied to promote oral health and access to dental health services (, ). However, it is disturbing that in developing countries there is still a risk of increasing dental caries due to unbalanced diet, uncontrolled sugar consumption, lack of application of fluoridation methods and inadequate oral health care ().

The group of children aged between 6 and 12 and adolescents are considered to be groups that are most affected by caries, therefore the WHO considers them target age groups to investigate into the level of caries in different countries around the world (). Children and adolescents are giving preferences to sweetened beverages and soft drinks, which are rich in carbohydrates, between meals. In addition, they have numerous engagements during the day. Consequently, the aforementioned are considered high hazards for dental caries, thus making the problem of caries prevalence even more significant at those ages (). Oral health goals framed jointly by the World Health Organization (WHO) and the FDI-World Dental Federation for the year 2000 included a 50% reduction of dental caries for 6-year-olds, an average DMFT index of no more than 3.0 for 12-year-olds, and 85% of the population up to the age of 18 should have all of their teeth ().

Oral health as an important part of overall health enables a person to eat, talk, and to be socialized. Subsequently, this affects the overall well-being of each individual (). School age is a period of great influence on the development of a child's personality, as well as on the behaviors related to oral health. Hence, it is important to teach children and adolescents good oral health behaviors because they will carry those valuable lessons with them as they get older (). Particularly, it is important to possess knowledge about dietary habits, brushing habits and dental visits, which will enable individuals to have good oral health (, -). The results of numerous studies showed that most children brush their teeth once a day (, ). A number of dental caries studies have been conducted in Kosovo, and the results have shown that the rate of dental caries is quite high (-).

Within this context, this study aimed to evaluate the prevalence of caries and to analyze related risk factors among 15-year-old adolescents from different cities of Kosovo.

Material and methods

This study involved an epidemiological cross-sectional data collected in several schools in different cities of Kosovo during 2017/2018. Accordingly, the adolescents from every public school from cities of Kosovo had an equivalent occasion of participating in the study. An electronic invitation was delivered to each school of Kosovo to examine the adolescents, and afterward, the first of them who positively replied to the invitation were selected for further research. The sample and the classroom were randomly selected in each public school. The sample included 323 adolescents of both genders. The study was approved by the Ministry of Education, Science, and Technology of the Republic of Kosovo (approval number: 3752/2016). Firstly, each parent was informed by the school board prior to data collection and then a consent form was obtained for each adolescent examined.

Two working teams were formed to conduct the research; each team consisted of a pediatric dentist and three students in the final year of dentistry studies. A pediatric dentist with clinical and epidemiological experience has trained the examiners to use the methodology according to the criteria of the World Health Organization (WHO), 1997, for epidemiological studies (). In recording caries severity, the Decayed, Missing and Filled Tooth (DMFT) index was used for 15-year-old adolescents. Oral hygiene status was assessed by using evaluation criteria described by Green and Vermillion, 1964, for use of the Simplified Oral Hygiene Index (OHI-S Index) (). Dental caries and the OHI-S Index were diagnosed under natural light, using the following dental instruments: a mirror and a probe. Dental examinations were performed at school during daytime hours by two calibrated examiners (Kappa=0.96-intraexaminer and 0.94-interexaminer). The clinical findings were recorded by a student assistant.

The questionnaire was administered to all 15-year-old adolescents attending grade 9 who were willing to take part in the study, in which demographic records (gender, habitation, simplified oral hygiene and dental status), the frequency of dental visits and the frequency of brushing habits were included. A questionnaire was pretested by adolescents’ one day before the examination to assess whether the questionnaire was understandable to the adolescents. Afterwards, the teachers supported the researchers and did not intercede in the administration of the structured questionnaire. Adolescents were asked about the frequency of brushing their teeth during the day (the main options were: twice or once a day and rare), whereas regarding dental visits the options were once in 6 months, once in year, and the third given option was only when necessary. The exclusion criteria applied in the current study were as follows: those who rejected to participate in the study, those undergoing orthodontic treatment, and healthy compromised adolescents. The inclusion criteria were: 15-year-old adolescents (both genders), who were present on the day of the examination. At the end of the examination, the parents of the adolescents who were in need of dental care were given a recommendation. Subsequently, a lecture about oral health and using the correct oral hygiene technique of toothbrushing was held in every classroom.

Statistical Analysis

Data were entered using SPSS package 19 for Windows (SPSS Inc., Chicago, Illinois, USA) software and descriptive data were obtained, included frequencies and means. The variances concerning means were established using the student t-test. The Spearman’s rank correlation (Spearman’s rho) was used to test the association between frequency of brushing habits, dental visits, OHI-S index and DMFT index. A level of p<0.05 was considered statistically significant.

Results

The characteristics of the adolescents by gender and the mean of DMFT index are presented in Table 1. The standard deviation and the mean for DMFT were found (3.21±2.193). Furthermore, the component D was more dominant among boys compared to girls (2.15±2.092 and 1.91±1.919), followed by F-component and M-component which tended to be comparable throughout both genders.

Table 1

Mean and standard deviation for DMFT components, DMFT free and OHI-S index based on gender

Gender	N	D	M	F	DMFT	DMFT free	OHI-S
		Mean ± SD	Mean ± SD	Mean ± SD	Mean ± SD	Mean ± SD	Mean ± SD
Girls	162	1.91±1.919	0.36±0.665	0.86±1.372	3.10±2.190	0.15±0.356	1.957±0.424
Boys	161	2.15±2.092	0.34±0.672	0.86±1.344	3.33±2.196	0.11±0.308	1.932±0.359
Overall	323	2.03±2.008	0.35±0.667	0.86±1.356	3.21±2.193	0.13±0.333	1.945±0.393

On the other hand, the overall OHI-S index was 1.945, slightly higher in girls (1.957) compared to boys (1.932) (Table 1).

The distributions of the frequencies related to brushing habits and dental visits are presented in table 2. According to the results obtained in this study, 65.6% of adolescents of both genders brush their teeth once a day. The percentage of adolescents who visited the dentist only when necessary exceeded 50% amongst both genders.

Table 2

Brushing habits per day and frequency of dental visits

Gender	Brushing habits per day			Dental visits
	Frequency	N	%	Frequency	N	%
Girls	Twice	4	2.5	Once in 6 months	46	28.4
	Once	86	53.1	Once in year	20	12.3
	Rare	72	44.4	Only when necessary	96	59.3
Boys	Twice	3	1.9	Once in 6 months	45	28.0
	Once	126	78.3	Once in year	24	14.9
	Rare	32	19.9	Only when necessary	92	57.1
Overall	Twice	7	2.2	Once in 6 months	91	28.2
	Once	212	65.6	Once in year	44	13.6
	Rare	104	32.2	Only when necessary	188	58.2

By using the Spearman’s rank correlation, it was obvious that there was a significant association concerning the frequencies of brushing habits, dental visits, OHI-S index and DMFT index (Table 3).

Table 3

Conditional univariate logistic regression analysis of oral hygiene, dental visits, DMFT index, and OHI-S

Correlations
			Brushing habits per day	Dental visits	DMFT	OHI-S
Spearman's rho	Brushing habits per day	Correlation Coefficient	1.000	-.193**	.044	.005
		Sig. (2-tailed)	.	.000	.426	.928
		N	323	323	323	323
	Dental visits	Correlation Coefficient	-.193**	1.000	.096	.119*
		Sig. (2-tailed)	.000	.	.085	.032
		N	323	323	323	323
	DMFT	Correlation Coefficient	.044	.096	1.000	.663**
		Sig. (2-tailed)	.426	.085	.	.000
		N	323	323	323	323
	OHI-S	Correlation Coefficient	.005	.119*	.663**	1.000
		Sig. (2-tailed)	.928	.032	.000	.
		N	323	323	323	323
**. Correlation is significant at the 0.01 level (2-tailed).*. Correlation is significant at the 0.05 level (2-tailed).

Discussion

Oral health is not only a necessary component of overall health, but it also affects the quality of life. Dental caries is the most common oral problem affecting more than 2 billion people worldwide. According to the WHO report, dental caries is a chronic disease ranked as fourth most expensive medical treatment (-).

This study offered a broad overview and evidence on the level of DMFT index, OHI-S index, and behaviors related to dental brushing habits and dental visits among 15-year-old adolescents in Kosovo. This is worthwhile in a population without previous data presented on dental caries among 15-year-old adolescents, as is the case of Kosovo. The present study showed high scores of the DMFT index among the examined adolescents, and the DMF-index was totally dominated by the D component. The results concerning gender showed that boys had higher DMFT index values compared to girls. Those results are corresponding with previous reports (-), but the values were higher than those in studies conducted by others (-), and considerably lower than reported in other studies (-). Such high values can be explained by the deficiency of national preventive programs, the shortage of dentists in schools, as well as the lack of preventive and educational measures in Kosovo.

Oral Hygiene Index (OHI-S) has been accepted as useful index for assessment of dental health education in public school systems, and it is also considered an indication of oral hygiene (). The level of oral hygiene in our study is considered to be low, and similar values were also found in previous study conducted in our country in different group ages (). Also, contrary to our results, other studies observed better oral hygiene, which was also correlated with a lower level of dental caries (, , ). Good oral hygiene practice is the most significant feature determining the general oral health of an individual. The most common aids used for maintaining oral hygiene were toothbrushes and toothpaste. They decrease plaque accumulation within which oral bacteria survive to produce acid that increases the risk of caries. Attaining good oral hygiene practice early in life by the child does improve upright practices later throughout life (). The current study showed that most of adolescents in Kosovo brush their teeth only once a day, which caused an increase in the level of caries and plaque index. This may be related to improper toothbrushing time, inefficient brushing technique or both. There is a discrepancy between our results and the results of previous studies where adolescents of the same age brushed their teeth more than once a day (, , ). Moreover, in disagreement with our study, females, as compared to males, had significantly higher-performing oral hygiene habits such as tooth brushing twice a day and they brushed their teeth after their last meal before bedtime (). This is not surprising since adolescents are not examined yearly by a dental team and they are not educated about the need of brushing their teeth regularly and, also, about the benefits of using toothpastes containing fluoride. Regular twice-daily toothbrushing with fluoridated toothpaste is a recommended practice for good oral health.

In addition, the adolescents participating in current study reported that they visited the dentist only when it was necessary, in which case a substantial positive correlation was established amongst the overall oral hygiene status, dental caries, and the frequency of brushing habits and the frequency of dental visits. Conversely, a number of other studies reported contradictory results regarding the frequency of dental visits: it was higher than once a year (, ). Preventive dental visits are highly recommended, but in Kosovo there seems to be still a long way to go since dental visits are generally associated with a worse caries status. Thus, these aspects should focus on more targeted and effective oral health promotion initiatives in the future. A greater understanding of these risk factors is indispensable in order to identify the population’s oral health status, thus learning how to improve it. Understanding risk factors can contribute to development of more effective dental public health policies.

This study has some strengths and limitations. The main strength of the current study includes the assessment of oral status according to WHO procedures and criteria for epidemiological studies so that our results obtained in Kosovo can be compared with those from different countries in the future. Strengths also include necessary steps and pilot test for intra-examiner and inter-examiner agreement, so that obtained results are consistent and reliable. Few limitations of the study must be well-thought-out. In Kosovo, adolescents from higher socioeconomic backgrounds are likely to be enrolled in private schools and we did not make the comparison regarding oral health between public and private adolescents, nor between urban and rural residents. Consequently, the existing relationships with other risk factors heretofore described as cariogenic diet, socio-economic status, family income, parents’ age, educational level and occupation, and anxiety about dental treatment, were not analyzed (, , , ). These circumstances are interesting due to the possible interaction with the variables described in this study.

However, the results of this study suggest a possible association of the existing low level of oral health knowledge in the study population with high level of dental caries, which was published in previous research.

Conclusions

In conclusion, the prevalence of dental caries in Kosovo schoolchildren was high, which is consistent with the results obtained in previous research. However, the prevalence of caries is still much higher than in most European countries. Restorative and preventive public health promotions are exceedingly suggested to improve oral health status among Kosovo adolescents. Caries prevention measures should be taken thoroughly and on a huge scale, primarily in the form of fluoride management (brushing with fluoride gel, tablets), application of dental sealants in order to avoid extensive restorative procedures in the future, and education for healthier oral hygiene. Furthermore, comprehensive tooth brushing with concentrated fluoride gel is recommended for caries prevention in primary and permanent teeth of children in elementary schools.