A study of salivary peptide profile in children with early childhood caries: envisioning saliva as a diagnostic tool

FundaÃÃo Cearense de Apoio ao Desenvolvimento Cientifico e TecnolÃgico === The aim of the present study was to find a relation between salivary peptides, caries experience and mutans streptococci (MS) levels in saliva of caries free (CF) and caries susceptible (CS) children in early childhood. One h...

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Bibliographic Details
Main Author: Thyciana Rodrigues Ribeiro
Other Authors: Cristiane SÃ Roriz Fonteles
Format: Others
Language:Portuguese
Published: Universidade Federal do Cearà 2009
Subjects:
Online Access:http://www.teses.ufc.br/tde_busca/arquivo.php?codArquivo=3576
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Summary:FundaÃÃo Cearense de Apoio ao Desenvolvimento Cientifico e TecnolÃgico === The aim of the present study was to find a relation between salivary peptides, caries experience and mutans streptococci (MS) levels in saliva of caries free (CF) and caries susceptible (CS) children in early childhood. One hundred and six 10 â 71 month-old children participated in the study. Fifty-eight children were CF and 48 who had experienced dental caries formed the CS group. Two samples of whole saliva were collected from all participants. Unstimulated whole saliva was collected, subsequently centrifuged. Supernatants were lyophilized, divided into two pools (CF and CS) and individual samples, and stored at -20oC for posterior analysis using LC-MS (Liquid Chromatography Mass Spectrometry) to study the peptide profile. Identification of salivary peptides was based on theoretical molecular masses available from online databases. Stimulated whole saliva was collected and used for MS detection in MSB agar medium. MS concentration in saliva was reported in cfu/mL. Dental examination was performed and dmfs/dmft scores were calculated. Data was analysed by using logistic regression. The chromatograms from CF and CS pools of saliva had different peak patterns. The identification of molecular masses suggested the presence of 9 peptides. Three of them were significantly related with caries experience. The presence of HNP-3 (&#945;-defensin 3) (p = 0.019) and HBD-3 (&#946;-defensin 3) (p = 0.034) reduced the chances of experiencing early childhood caries (ECC). The presence of PRP IB-4 significantly increased caries experience (p = 0.035). In addition, age (p = 0.020) and MS counts (p = 0.036) increased caries experience, however gender was not associated with dental caries (p = 0.877). Our results suggest that presence of specific peptides in saliva of CF or CS children in early childhood predisposes to a higher or lower risk of caries experience. === Este trabalho buscou estudar o perfil de peptÃdeos salivares de crianÃas com cÃrie da primeira infÃncia, relacionando-o com nÃveis de estreptococos do grupo mutans (EGM) salivares e experiÃncia de cÃrie. Cento e seis crianÃas, na faixa etÃria de 10 a 71 meses de idade, participaram do estudo, sendo 48 com experiÃncia de cÃrie e 58 sem cÃrie da primeira infÃncia. Duas amostras de saliva total foram coletadas de todos os participantes. A primeira amostra era composta de saliva nÃo estimulada, utilizada para anÃlise dos peptÃdeos. ApÃs coletada, essa saliva foi centrifugada, o sobrenadante retirado, liofilizado, dividido em pools com cÃrie, sem cÃrie e em amostras individuais e armazenado em freezer a -20oC atà anÃlise em aparelho de LC-MS (Cromatografia LÃquida acoplado ao EspectrÃmetro de Massa). A busca por peptÃdeos foi baseada em massas conhecidas de peptÃdeos existentes em bancos de dados. Saliva estimulada representou a segunda coleta, utilizada para o cultivo dos EGM (UFC/mL) em meio Ãgar mitis salivarius bacitracina (MSB). Anamnese e exame dentÃrio foram realizados para cÃlculo do Ãndice ceo-s e ceo-d. Os dados foram analisados por meio de modelo logÃstico binÃrio. Resultados foram considerados significantes quando p-valor < 0,05. Os cromatogramas obtidos a partir dos pools de crianÃas com/sem cÃrie apresentaram diferenÃas em relaÃÃo aos picos apresentados. A identificaÃÃo das massas moleculares sugeriram a presenÃa de nove peptÃdeos. RegressÃo logÃstica mostrou que 3 peptÃdeos se relacionaram com experiÃncia de cÃrie. PRP IB-4 associou-se a um aumento de experiÃncia de cÃrie (p=0,035); &#945;-defensina 3 (p=0,019) e &#946;-defensina 3 (p=0,034) associaram-se à reduÃÃo de experiÃncia de cÃrie. Em adiÃÃo, aumento na idade (p=0,020) e aumento na contagem de EGM (p=0,036) ocasionaram um aumento na experiÃncia de cÃrie, mas sexo nÃo se relacionou com cÃrie dentÃria (p=0,877). A partir desses resultados, pÃde-se concluir que a presenÃa de peptÃdeos especÃficos na saliva de crianÃas com e sem cÃrie dentÃria predispÃem a um maior ou menor risco à essa doenÃa.