<?xml version="1.0" encoding="UTF-8"?><?xml-stylesheet type="text/xsl" href="static/style.xsl"?><OAI-PMH xmlns="http://www.openarchives.org/OAI/2.0/" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://www.openarchives.org/OAI/2.0/ http://www.openarchives.org/OAI/2.0/OAI-PMH.xsd"><responseDate>2026-09-18T18:24:23Z</responseDate><request verb="GetRecord" identifier="oai:helda.helsinki.fi:10138/235786" metadataPrefix="dim">https://helda.helsinki.fi/server/oai/request</request><GetRecord><record><header><identifier>oai:helda.helsinki.fi:10138/235786</identifier><datestamp>2026-07-23T12:41:27Z</datestamp><setSpec>com_10138_18086</setSpec><setSpec>com_10138_17738</setSpec><setSpec>col_10138_2271</setSpec></header><metadata><dim:dim xmlns:dim="http://www.dspace.org/xmlns/dspace/dim" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:doc="http://www.lyncode.com/xoai" xsi:schemaLocation="http://www.dspace.org/xmlns/dspace/dim http://www.dspace.org/schema/dim.xsd">
   <dim:field mdschema="dc" element="contributor" lang="fi">Helsingin yliopisto, Lääketieteellinen tiedekunta</dim:field>
   <dim:field mdschema="dc" element="contributor" lang="en">University of Helsinki, Faculty of Medicine</dim:field>
   <dim:field mdschema="dc" element="contributor" lang="sv">Helsingfors universitet, Medicinska fakulteten</dim:field>
   <dim:field mdschema="dc" element="contributor" qualifier="author">Räisänen, Ismo</dim:field>
   <dim:field mdschema="dc" element="contributor" qualifier="thesisadvisor">Heikkinen, Anna Maria</dim:field>
   <dim:field mdschema="dc" element="contributor" qualifier="thesisadvisor">Sorsa, Timo</dim:field>
   <dim:field mdschema="dc" element="date" qualifier="issued">2018</dim:field>
   <dim:field mdschema="dc" element="identifier" qualifier="uri">URN:NBN:fi:hulib-201805242054</dim:field>
   <dim:field mdschema="dc" element="identifier" qualifier="uri">http://hdl.handle.net/10138/235786</dim:field>
   <dim:field mdschema="dc" element="description" qualifier="abstract" lang="fi">Tämän poikkitieteellisen tutkimuksen tarkoituksena on selvittää, kuinka erilaiset potilaskohtaiset riski-indikaattorit voisivat vaikuttaa nuorten alkavan parodontiitin, jota kutsumme preparodontiitiksi, kehittymisen mahdollisuuteen. Tutkimusaineisto koostuu yhteensä 210 suomalaisnuoresta (118 poikaa / 92 tyttöä, ikä 15-16 vuotta). Sen on kerännyt erikoiskoulutuksen saanut hammaslääkäri kliinisellä tutkimuksella ja kyselytutkimuksella. Aineisto sisältää potilaista seuraavat tiedot: parodontologiset indeksit (ienverenvuoto, näkyvän plakin indeksi, hammaskivi ja ientaskunsyvyys), tupakointistatus ja -määrä, parodontiittibakteerit (Aggregatibacter actinomycetemcomitans, Porphyromonas gingivalis, Tannerella forsythia, Prevotella intermedia, Prevotella nigrescens and Treponema denticola) ja syljen parodontiittibiomerkkiaineet (MMP-8, PMN elastaasi, proteiini, albumiini, IgA, IgG, and IgM). Tulosten analysoinnissa käytettiin logistista regressiota ja Mann-Whitney U -testiä.&#xd;
&#xd;
Tutkimuksen päätulos oli se, että nuorten preparodontiitti oli tilastollisesti merkitsevästi assosioitunut syljen kohonneen MMP-8:n muttei PMN elastaasin kanssa. Lisäksi nuorilla preparodontiittipotilailla oli tilastollisesti merkitsevästi runsaammin ienverenvuotoa, hammaskiveä ja plakkia kuin ei-preparodontiittipotilailla. Tulosten perusteella näyttäisi siltä, että nuorten alkavan parodontiitin pääriskitekijä on (osittain kalkkeutunut) dysbioottinen bakteeribiofilmi, joka johtaa ientulehdukseen ja ≥ 4 mm syviin ientaskuihin vuorovaikuttaessaan isännän immuunipuolustuksen kanssa. Tämä proinflammatorinen preparodontiittivaihe näkyy syljen kohonneena MMP-8-tasona. Tutkimuksen tulokset voivat auttaa kehittämään uusia tehokkaampia tapoja tunnistaa nuoret kohonneen preparodontiittiriskin potilaat (mm. suunesteen MMP-8-pitoisuutta mittaavat ns. tuolivierustestit).</dim:field>
   <dim:field mdschema="dc" element="description" qualifier="abstract" lang="en">Aim: To find out how different patient-related risk indicators might be associated with the odds of developing preperiodontitis in adolescents.&#xd;
&#xd;
Materials and methods: This cross-sectional study used total of 210 Finnish individuals (118 boys / 92 girls, aged 15-16). A specially trained dentist performed clinical examinations. Measurements included periodontal indexes (bleeding on probing, visible plaque index, root calculus and probing depth), smoking status, periodontal bacteria (Aggregatibacter actinomycetemcomitans, Porphyromonas gingivalis, Tannerella forsythia, Prevotella intermedia, Prevotella nigrescens and Treponema denticola) and salivary periodontal biomarkers (MMP-8, PMN elastase, protein, albumin, IgA, IgG, and IgM). Results were analyzed by logistic regression and Mann-Whitney U test.&#xd;
&#xd;
Results: The main finding of this study was that preperiodontitis in adolescents was statistically significantly associated with elevated salivary MMP-8 but not with PMN elastase. Also, adolescents with preperiodontitis had statistically significantly higher levels of bleeding on probing, root calculus and dental plaque than adolescents without preperiodontitis.&#xd;
&#xd;
Conclusions: We suggest that the main risk factor for preperiodontitis in adolescents is the (partly calcified) dysbiotic bacterial biofilm which leads to gingival inflammation and ≥ 4 mm periodontal pockets (through interaction with the immune defences of the host). This proinflammatory preperiodontitis stage is reflected as elevated salivary MMP-8.</dim:field>
   <dim:field mdschema="dc" element="language" qualifier="iso">eng</dim:field>
   <dim:field mdschema="dc" element="publisher" lang="fi">Helsingin yliopisto</dim:field>
   <dim:field mdschema="dc" element="publisher" lang="en">University of Helsinki</dim:field>
   <dim:field mdschema="dc" element="publisher" lang="sv">Helsingfors universitet</dim:field>
   <dim:field mdschema="dc" element="subject" lang="en">Adolescent</dim:field>
   <dim:field mdschema="dc" element="subject" lang="en">Periodontitis</dim:field>
   <dim:field mdschema="dc" element="subject" lang="en">Risk Factors</dim:field>
   <dim:field mdschema="dc" element="subject" lang="en">Matrix Metalloproteinase</dim:field>
   <dim:field mdschema="dc" element="subject" lang="en">Leukocyte Elastase</dim:field>
   <dim:field mdschema="dc" element="subject" qualifier="discipline" lang="en">Periodontology</dim:field>
   <dim:field mdschema="dc" element="subject" qualifier="discipline" lang="fi">Parodontologia</dim:field>
   <dim:field mdschema="dc" element="subject" qualifier="discipline" lang="sv">Parodontologi</dim:field>
   <dim:field mdschema="dc" element="title" lang="en">Risk factors for preperiodontitis in adolescents</dim:field>
   <dim:field mdschema="dc" element="type" qualifier="ontasot" lang="fi">pro gradu -tutkielmat</dim:field>
   <dim:field mdschema="dc" element="type" qualifier="ontasot" lang="en">master&amp;apos;s thesis</dim:field>
   <dim:field mdschema="dc" element="type" qualifier="ontasot" lang="sv">pro gradu-avhandlingar</dim:field>
   <dim:field mdschema="dc" element="rights" qualifier="accesslevel">restrictedAccess</dim:field>
   <dim:field mdschema="dct" element="identifier" qualifier="urn">URN:NBN:fi:hulib-201805242054</dim:field>
   <dim:field mdschema="others" element="access-status">restricted</dim:field>
</dim:dim></metadata></record></GetRecord></OAI-PMH>