The present study, the first of its kind among immigrants to Israel, offers a unique opportunity to examine the changes in oral health and behaviour of a large Ethiopian immigrant cohort, upon arrival and five years later.
In a survey conducted in Israel in 1994, among new Ethiopian immigrants, mean DMFT levels of 0.31, 1.27 and 5.26 were reported among 12, 35–44 and 51+ year olds, respectively [14
]. In the present study, at BL, mean DMFT levels of 0.61, 2.41 and 3.71 were found among the same age groups. These findings are in accordance with studies from Africa claiming that the previously predicted increase in caries in mainland Africa (including Ethiopia) has not occurred. In contrast to what was anticipated, caries experience is fairly stable and remains at a reasonably low level [16
Notwithstanding increasing caries experience after immigration, among this Ethiopian cohort, levels remained remarkably low. Among both 6 and 12-year-olds, levels remained less than DMFT = 1, even after five years.
Among Israelis, a mean score of DMFT = 1.66 was recently found among 12-year-olds, and among 21-year- olds, a mean score of DMFT = 8.5 was demonstrated [9
]. These levels can be compared with 0.81 (12 yr olds) and 1.34 (18 yr olds) in the present study.
International data have revealed that immigrants and minority ethnic groups should be regarded as prone towards oral health deterioration [5
]. Over time, Ethiopian immigrants experience a profound change in lifestyle and culture. Following a short adaptation and acclimation period at absorption centers, the immigrants are scattered among towns across the country, as opposed to their previous rural agricultural settings in Ethiopia, and were are expected to conduct their lives as ordinary citizens.
Over a five year period, among the present total study population, caries prevalence had increased from 29.9% to 46.7% and periodontal disease (existence of periodontal pockets) prevalence had dramatically increased from 5.3% to 24.4%.
An abrupt and extreme change has occurred in the oral hygiene health behaviour of this immigrants group. At baseline, 74% reported cleaning their teeth, exclusively utilizing chewing and cleaning sticks common in Ethiopia. After five years, 97% reported cleaning their teeth, exclusively utilizing toothbrushes common in Israel and the western world. In spite of the almost unanimous report, regarding tooth brushing five years after arriving to Israel, health deterioration has occurred. The replacement of the traditional chewing and cleaning sticks common in Ethiopia by "modern" tooth brushing in Israel, might be associated with the detection of periodontal health deterioration. It should be noted that other health behaviours, especially diet, were not recorded in the present study. Based upon previous research [13
], it can be assumed that a previous almost sugar-free diet had been abandoned in favour of high sugar intake.
Immigrant and minority groups in western societies require different information packages, modified strategies for forming oral hygiene habits, and encouragement to exercise discipline on factors known to be risks for oral health [5
Population strategies are the basis for all dental public health programs, for example water fluoridation and dental health education. Although, focused relief is often necessary, models which identify and then target individuals at high risk are far from precise at individual levels [19
]. Between these two approaches is geographic targeting, in which schools, school districts and even large regions can be identified at being at high risk [21
]. Rose has discussed the advantages and disadvantages of prevention by the "whole population" strategy, and the "high-risk" strategy, and concluded that the prior concern should always be to discover and control the cause of incidence, but the two approaches are not usually in competition [20
The present study among a large cohort of new immigrants might provide an opportunity for planning and implementing an "acclimatizing and integrating" model of oral health promotion among minority and immigrant groups, comprised of:
• Training of immigrant oral health professionals: dentists, dental hygienists, dental assistants and oral health promotion staff.
• Adaptation of an appropriate and optimal model of oral hygiene education together with consideration of previous behaviour and habits.
• Geographically targeted prevention programs in towns and neighbourhoods, populated by groups of immigrants.