Abstract Dental caries is one of the most widespread diseases in the world. In the industrialized world the situation improved until the 1990s, after which the good development is claimed to have almost stagnated. One of the aims of this cross-sectional study was to investigate caries prevalence in a young male population. Another aim was to investigate ways to find individuals needing restorative treatment. The hypothesis in this study was that caries prevalence among Finnish young males born in the 1990s was similar or even poorer compared to those born in earlier decades. Polarization of dental caries was still expected to exist. It was also hypothesized that caries prevalence is geographically unevenly distributed in Finland. The Finnish Defence Forces screening protocol was hypothesized to be valid for detecting individuals with restorative treatment need. Finally, it was hypothesized that restorative treatment need at the individual level associates well with a well-chosen set of questions concerning dental symptoms, dental attendance, treatment history and health behaviour. Study material consisted of 255 female and 13,564 male (total n=13,819) conscripts. Anamnestic data, along with information about the socioeconomic status, educational level and place of residence just before military service, were collected with computer-based questionnaire in connection with the oral screening (50 questions and 108 sub-questions). Validity of the screening protocol was evaluated in a sub-population (74 conscripts) examined using both the screening and the ICDAS classification. The screening protocol was validated using the ICDAS criteria and it proved to be well in accord with it considering restorative treatment need at the individual level. The study revealed that on average the conscripts had 1.4 decayed teeth (DT), third molars excluded. The number of decayed, earlier restored or extracted teeth due to caries (DMFT) was 4.1. Ten per cent had about half of the caries lesions and 30% had 90%, suggesting that polarization still exists. It was also found that living in areas with high fluoride content in drinking water, living in urban areas and a Swedish-speaking home municipality were protective factors against dental caries. A positive response to eight questions of a statistically selected set of ten questions reliably predicted restorative treatment need (OR 69.27). / Tiivistelmä Karies on yksi maailman laajimmalle levinneistä sairauksista. Menneinä vuosikymmeninä karies väheni merkittävästi aina 1990-luvulle saakka, jonka jälkeen myönteinen kehitys on hidastunut. Tämän tutkimuksen tavoitteena oli tutkia korjaavan hoidon tarpeen määrää nuorten miesten keskuudessa. Tutkimuksen toinen tavoite oli tutkia tapoja erottaa terveistä korjaavan hoidon tarpeessa olevat henkilöt. Tutkimuksen oletuksena oli, että karieksen esiintyvyys 1990-luvun alussa syntyneiden suomalaismiesten joukossa on vastaavalla tai huonommalla tasolla kuin 1970-luvun alussa. Lisäksi oletettiin, että kyseisessä ikäluokassa karies on polarisoitunut. Oletuksena oli myös, että karieksen esiintyvyys on maantieteellisesti epätasaisesti jakaantunut. Tutkimuksessa oletettiin myös, että Suomen Puolustusvoimien käyttämällä suunterveyden seulontamenetelmällä voidaan tunnistaa luotettavasti yksilötasolla korjaavan hoidon tarpeessa olevat yksilöt. Viimeisenä oletuksena oli, että korjaavan hoidon tarve yksilötasolla olisi arvioitavissa seulonnan ja hyvin valitun kysymyspaketin perusteella tutkituissa ikäluokissa. Tämän poikittaistutkimuksen satunnaistettu tutkimusaineisto koostui 13819 varusmiehestä (255 naista ja 13564 miestä) sekä esitietoihin perustuvasta aineistosta joka kerättiin seulonnan yhteydessä tietokonepohjaisella kyselylomakkeella (50 kysymystä ja 108 alakysymystä). Seulonnan tulokset vastasivat hyvin tarkastusta, jossa vauriot diagnosoitiin ICDAS kriteereitä käyttäen. Tutkimus osoitti myös että, keskimäärin yksilöllä oli 1,4 korjaavan hoidon tarpeessa olevaa hammasta viisaudenhampaat pois lukien. Aiemmin korjattujen, karieksen takia poistettujen ja karieksen vaurioittamien hampaiden lukumäärä oli 4,1. Kymmenellä prosentilla tutkimusjoukosta oli puolet kaikista vaurioista ja vastaavasti kolmanneksella tutkituista oli 90 prosenttia kaikista vaurioista. Juomaveden fluoripitoisuus ja asuminen kaupungissa tai ruotsinkielisessä kunnassa olivat suojaavia tekijöitä korjaavan hoidon tarpeen suhteen. Kymmenen esitietokysymystä valittiin tilastollisesti 108 kysymyksen joukosta. Positiivinen, korjaavalle hoidolle altistava, vastaus vähintään kahdeksaan näistä kymmenestä kysymyksestä ennusti luotettavasti (OR 69,27) korjaavan hoidon tarvetta yksilötasolla.

CoordenaÃÃo de AperfeiÃoamento de Pessoal de NÃvel Superior / Esta investigaÃÃo propÃe o desenvolvimento de um mÃtodo para a localizaÃÃo e prediÃÃo das caracterÃsticas geotÃcnicas dos solos que possa contribuir para o processo da tomada de decisÃo, quanto à sua utilizaÃÃo, para fins de pavimentaÃÃo. Utilizou-se Geoprocessamento e Redes Neurais Artificiais (RNAs) como tÃcnicas de modelagem, bem como variÃveis biofÃsicas e espaciais como explicativas dos fenÃmenos modelados. As caracterÃsticas pesquisadas (pedologia, geologia, geomorfologia, vegetaÃÃo, altimetria e posiÃÃo) se correlacionaram com as variÃveis geotÃcnicas estimadas (classificaÃÃo TRB - Transportation Research Board e CBR - California Bearing Ratio) para solos provenientes da RegiÃo Metropolitana de Fortaleza (RMF). Assim, desenvolveu-se trÃs modelos de RNAs que foram calibrados, validados e testados. Dois desses modelos foram dedicados à geraÃÃo de estimativas de CBR nas energias de compactaÃÃo normal (CBR-N) e intermediÃria (CBR-I). O terceiro modelo foi elaborado para geraÃÃo de estimativas da classificaÃÃo TRB dos solos da RMF. As caracterÃsticas geotÃcnicas estimadas por estes modelos possibilitaram a elaboraÃÃo dos chamados Mapas GeotÃcnicos Neurais, estratificados para previsÃo dos valores de CBR-N, CBR-I e ClassificaÃÃo TRB. Adicionalmente, os mapas produzidos e todas as informaÃÃes da pesquisa foram disponibilizados em um Sistema de InformaÃÃes GeogrÃficas Web (SIG-Web), de forma a possibilitar seu uso em projetos viÃrios e estudos acadÃmicos futuros, tanto para download dos mapas gerados, quanto para geraÃÃo de estimativas para uma Ãrea especÃfica da RMF. AlÃm disso, disponibilizou-se ao SIG-Web um realimentador de pontos geotÃcnicos para permitir uma recalibraÃÃo futura dos modelos na tentativa de melhorar a qualidade das estimativas geradas que atualmente à superior a 90% de taxa de acerto. / This research focuses on the development of a method, aimed to predicting and positioning the geotechnical characteristics of soils that may contribute to the process of decision making of its use for paving purposes. Were used Geoprocessing and Artificial Neural Networks (ANN) modeling techniques, as well as spatial and biophysical variables of the phenomena modeled. The characteristics studied (pedology, geology, geomorphology, vegetation, altimetry and position) were correlated with the estimated geotechnical variables (TRB Classification and CBR) for soils from the metropolitan region of Fortaleza, Cearà (RMF). Three models of ANNs were developed calibrated, validated and tested. Two of these models were dedicated to generating estimates of CBR in the normal (CBR-N) and intermediate (CBR-I) compaction modes. The third model was developed to generate estimates of the geotechnical characteristics of the soils from the RMF Classification TRB. The geotechnical characteristics estimated by these models enabled the preparation of Neural Geotechnical Maps, stratified for values of CBR-N, CBR-I and TRB Classification. The maps produced and all the survey information was made available on a Web Geographic Information System (Webmapping), thus allowing its use in road projects and future academic studies, both to download the maps and to generate estimates for RMF. In addition, provided to the Webmapping a geotechnical receiver points, to allow recalibration of future models in an attempt to improve the quality of the estimates that currently is more than 90% accuracy rate.