Introduction
Dental caries is a breakdown of teeth due to acids made by bacteria [1]. It is a major public health issue and the most widespread chronic disease [2]. In America, Dental caries is the most common chronic disease among childhood [3]. Dental caries is a major public health problem in Iraq. Dental caries, or cavities, commonly known as tooth decay, are caused by a breakdown of tooth enamel [3]. Though dental caries is the most common infectious disease in the world, we can minimize by educating our students and children about causes [4]. It can be easily prevented with the implementation of simple preventive measures, including use of sealants to safe coat pits and fissures, fluoride supplementation, water, and milk fluoridation, and reducing sweet consumption [5].
This report presents the most recent key information on oral health and dental care of the Australian population. Oral health: In 2010, 48% of 12-year-olds had experienced decay [6].

In sub-Saharan Africa, oral health services are characterized by few oral health care personnel typically leaving the rural and peri-urban communities with only emergency care. The presence of many life-threatening health problems and vast developmental needs contribute to the low priority given to oral health problems in the area [5].
The World Health Organization recognizes dental caries as pandemic disease and reports that its prevalence among school-aged children ranges from 60% to 90% [7].
The prevalence of dental caries in different studies was reported to be 50% in COIMBATORE[8] 14.9% in Tanzania among old adults [8], 24.1% in Nigeria [9], 78% 30.5% in Sudan [10], and in Ethiopia indicated that dental caries 48.5% [11].Additional Community-based study done Addis Ababa, Ethiopia the prevalence of dental caries was reported 47.4 % [5]. The burden of the oral problem is particularly high for the disadvantaged and poor population groups in both developing and developed countries.
Oral diseases such as dental caries, periodontal disease, tooth loss, oral mucosal lesions and oropharyngeal cancers [2]. Dental caries is the most common chronic disease among youth aged 6-19 years [12].
In Ethiopia, Primary School Students oral health problems prevention and treatment gets inadequate attention in the government. Although dental caries is practiced in some parts of the country, there is not still clearly identified the major problem in the study area. Therefore this study aimed to assess the prevalence of dental caries and its associated factors among Aksum Primary school students.

An institution-based cross-sectional study was conducted from January 10 up to February 7, 2019. Aksum town which is found in the northern part of the Ethiopia, which is far 1024 kilometers from Addis Ababa the capital city of Ethiopia as well as 241 km from the capital city of the Tigray region Mekelle. It is one of the highly populated areas which accompanied around 65,000 as the 2017 report of the municipal city of the town; which are 49.2% male, the rest females and from the total population 12,616 are youths according to reports from the city administration. The distribution of health institutions is one comprehensive specialized hospital, one general hospital, two health centers, and four private higher clinics. It has weyna-dega air condition and midlevel rainfall annually.
Ethical approval was obtained from the Aksum university college of health science health Research ethical review committee (date: 11/02/2019, Ref: IRB091/2019), as well as oral and written informed consent from each participant before beginning the studies.

All respondent completed a questionnaire that includes demographic data i.e. Sex, Age Residency, Religion, educational level, family income. Most of the questions in the questionnaire were of the multiple-choice type. In addition all participants were asked about number of natural tooth, experience of tooth pain, Tooth brushing habit, material used to clean, toothpaste use, and toothpaste with fluoride, habit of fresh fruits diet habit of honey diet, habit chewing gum, Consumption of sugar foods, frequency of sweet / candy, use of snuff, tea, coffee with sugar habit, cigarettes smoking habit, chat chewing habit, frequency soft drink. The questions were based on the questionnaire from our previous study.

Using a single population proportion formula. The sample size is calculated prevalence dental caries48.5% in the previous study in Bahr dar [12], with 5% marginal error, 95% and confidence interval (CI).Based on this assumption, the actual sample size for the study was393

Data were collected using a questionnaire, which was adopted from different kinds of literature and the hospital's clinical record format. Those patients' clinical records that were not complete or were missing data were omitted and were replaced with the next patient's documented from the sampling frame. The data collection item was checked for its completeness and consistency with the patient's clinical records by the investigators on a daily basis.

Permission was got from the hospital management committee. The patients' clinical records were reviewed anonymously, and all information obtained from clinical records was kept confidential. Verbal consent was agreed by data managers of the hospital. Moreover, information was recorded anonymously and confidentially

Data were entered into SPSS software Version 22 and were analyzed according to the different variables. The finding was presented by using mean, standard deviation (SD), and simple frequency tables with percentages. The prevalence of dental caries was determined as the proportion of dental problem patients recorded who have one or more risk factors. Univariate and multivariate analysis logistic regression models were used to describe the significance of the association between the prevalence of dental caries between selected variables. Crude and adjusted odds ratios (CORs and AORs, respectively) with 95% confidence intervals (CIs) were used to describe the strength of association between the study variables. Significance was declared at P, 0.05.

The number of participants (n =393) Aksum Primary School Students Aged 6-15 years actively attend the school.

A total of 393 children participated in the study. Of these, 236 (60.1%) were male. Nearly half of children (51.5%) were from 11 to 15 years of age. Majority of the study participants were orthodox by religion (71.5%). Two hundred sixty-nine (68.4%) of the participant's family earned more than 1000 Ethiopian birr per month (Table 1).

One hundred fifty-nine (56.8%) of the children had experience with tooth pain. Most of the children (94.9%) didn't Tooth brushing habit. Sixty-four (65.3%) of the participants drank coffee with sugar every day. Sixty-seven (56.8%) of the children drank several times of sugar per day. Sixty (89.6%) of the children used to honey. 71(67.6%) of the children were used to clean their teeth (Table 2,3).

In Ethiopia, there is a lack of data on dental caries in primary school children. In this study, dental caries is a common health problem among primary school children.
The prevalence of dental caries found in the present study was 35.4% which is comparable with a study conducted in Ethiopia, Harar (36.9%) [12], North West Ethiopia 36.3% [13], Nepal 41% [14], but it was less than studies conducted in Bahr dar (75% ) [15], India (77%) [16]. On the other hand, the finding is higher with the study carried out in Uganda and Tanzania(17.6%) [17]. The difference could be due to the difference in awareness of oral hygiene as our study was undertaken among primary school children. In addition, the lower sample size in the present study might be accounted for the difference. Due to the shortage of dental insurance and families lacking the usual source of dental care, previous studies have reported that primary school children living in low socio-economic have a higher prevalence of dental caries [18]. The middle-income group had a higher prevalence than the highest income group.
On bivariate analysis, the habit of eating sweet foods has significantly associated with tooth decay. This result was in similar to a study conducted in other countries [15,19-21]. This might be related to copious acid production by microorganisms like bacteria to teeth as a result of fermentation of the sweet foods. Gradually the enamel of the tooth went into dental caries [22-24].

The majority of the students had primary school students had dental caries

We would like to forward our gratitude to the college of health science at Aksum University, School of Nursing. We are also grateful to the Aksum town health bureau and St. marry hospital. Lastly but not the least we thank the data collectors and respondents.

Conceptualized and designed the study: TZ. Analyzed the data: TZ LM MZ. Contributed materials analysis tools; LM MZ. Wrote the paper: TZ LM MZ.

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