Doctor of Philosophy / Dental caries continues to be a significant public health problem affecting mankind in many parts of the world. Microbial activities include the progressive localised destruction of teeth that without treatment, would eventually result in infection of the dental pulp and surrounding periapical tissues. Although the bacteria responsible for caries initiation and early caries progression have been extensively studied, the microbiology of dentine caries is reported to show considerable diversity and has not yet been fully identified. Few studies have analysed the microbiology of deep caries or examined the relationship between the microflora and the histopathy of chronic pulpits in symptomatic teeth. Matched carious dentine samples and dental pulps were obtained from teeth without evidence of periodontal disease but with coronal caries and symptoms of pulpits. Bacteria were cultured from the carious dentine samples under both anaerobic and microaerophilic conditions. Real-time polymerase chain reaction (PCR) technology was also used to identify and enumerate the bacteria. Development of the techniques for the efficient extraction of bacterial DNA from both Gram-negative and Gram-positive bacteria found in carious dentine was an essential prerequisite for molecular analysis. In addition, the dental pulps were processed and categorised into one of four groups on the basis of dominant pathology of the tissue (minimal inflammation, soft tissue degeneration, hard tissue degeneration, inflammatory degeneration). Analysis of the culture data indicated a predominance of Gram-positive bacteria, particularly lactobacilli, while Gram-negative bacteria were also present in significant numbers with Prevotella species the most numerous anaerobic group cultured. Real-time PCR indicated a greater anaerobic microbial load than that determined by colony counting. The total number of anaerobes detected by PCR was 41-fold greater, while Prevotella spp. and Fusobacterium ssp. were 82-fold and 2.4-fold greater respectively. PCR also identified the presence of Micromonas micros, Porphyromonas endodontalis and Porphyromonas gingivalis in 71%, 60% and 52% of carious dentine samples, respectively. Correlation matrices from the real-time PCR data revealed significant multiple associations involving Fusobacterium spp. in combination with P. endodontalis, M. micros and/or Prevotella in the tissue response categories of minimal inflammation, soft and hard disuse degeneration. A positive correlation was also observed between M. micros and P. endodontalis for the category of inflammatory degeneration of the dental pulp. These anaerobes have been strongly implicated in the endodontic infections that occur as sequelae to carious pulpitis. Accordingly, the data suggest that the presence of threshold levels of these bacteria in carious dentine may be indicative of irreversible pulpitis. Knowledge of the microbial predictors associated with irreversible pulpitis creates potential for the development of a diagnostic tool, and for restorative materials with antimicrobial properties.

Doctor of Philosophy / This work was digitised and made available on open access by the University of Sydney, Faculty of Dentistry and Sydney eScholarship . It may only be used for the purposes of research and study. Where possible, the Faculty will try to notify the author of this work. If you have any inquiries or issues regarding this work being made available please contact the Sydney eScholarship Repository Coordinator - ses@library.usyd.edu.au

Doctor of Philosophy / Dental caries continues to be a significant public health problem affecting mankind in many parts of the world. Microbial activities include the progressive localised destruction of teeth that without treatment, would eventually result in infection of the dental pulp and surrounding periapical tissues. Although the bacteria responsible for caries initiation and early caries progression have been extensively studied, the microbiology of dentine caries is reported to show considerable diversity and has not yet been fully identified. Few studies have analysed the microbiology of deep caries or examined the relationship between the microflora and the histopathy of chronic pulpits in symptomatic teeth. Matched carious dentine samples and dental pulps were obtained from teeth without evidence of periodontal disease but with coronal caries and symptoms of pulpits. Bacteria were cultured from the carious dentine samples under both anaerobic and microaerophilic conditions. Real-time polymerase chain reaction (PCR) technology was also used to identify and enumerate the bacteria. Development of the techniques for the efficient extraction of bacterial DNA from both Gram-negative and Gram-positive bacteria found in carious dentine was an essential prerequisite for molecular analysis. In addition, the dental pulps were processed and categorised into one of four groups on the basis of dominant pathology of the tissue (minimal inflammation, soft tissue degeneration, hard tissue degeneration, inflammatory degeneration). Analysis of the culture data indicated a predominance of Gram-positive bacteria, particularly lactobacilli, while Gram-negative bacteria were also present in significant numbers with Prevotella species the most numerous anaerobic group cultured. Real-time PCR indicated a greater anaerobic microbial load than that determined by colony counting. The total number of anaerobes detected by PCR was 41-fold greater, while Prevotella spp. and Fusobacterium ssp. were 82-fold and 2.4-fold greater respectively. PCR also identified the presence of Micromonas micros, Porphyromonas endodontalis and Porphyromonas gingivalis in 71%, 60% and 52% of carious dentine samples, respectively. Correlation matrices from the real-time PCR data revealed significant multiple associations involving Fusobacterium spp. in combination with P. endodontalis, M. micros and/or Prevotella in the tissue response categories of minimal inflammation, soft and hard disuse degeneration. A positive correlation was also observed between M. micros and P. endodontalis for the category of inflammatory degeneration of the dental pulp. These anaerobes have been strongly implicated in the endodontic infections that occur as sequelae to carious pulpitis. Accordingly, the data suggest that the presence of threshold levels of these bacteria in carious dentine may be indicative of irreversible pulpitis. Knowledge of the microbial predictors associated with irreversible pulpitis creates potential for the development of a diagnostic tool, and for restorative materials with antimicrobial properties.

Doctor of Philosophy / This work was digitised and made available on open access by the University of Sydney, Faculty of Dentistry and Sydney eScholarship . It may only be used for the purposes of research and study. Where possible, the Faculty will try to notify the author of this work. If you have any inquiries or issues regarding this work being made available please contact the Sydney eScholarship Repository Coordinator - ses@library.usyd.edu.au

Thesis (Ph. D.)--Institute of Dental Research, Faculty of Dentistry, University of Sydney, 2002. / Title from title screen (viewed Apr. 23, 2009) Submitted in fulfilment of the requirements for the degree of Doctor of Philosophy to the Faculty of Dentistry. Includes bibliography. Also available in print form.

Thesis--University of Lund. / Includes reprints of the author's articles. Includes bibliographical references.

Orientador: Luciano Tavares Angelo Cintra / Coorientador: André Luiz Fraga Briso / Banca: Denise Pedrini Ostini / Banca: Renata Oliveira Samuel / Resumo: Novos produtos estão sendo desenvolvidos com o propósito de atenuar os efeitos dos compostos utilizados em procedimentos clareadores. O objetivo do presente estudo foi avaliar in vivo o potencial terapêutico do gel de Biosilicato® (BS) sobre o tecido pulpar de molares de ratos Wistar, por meio das análises histológica e imunoistoquímica, assim como analisar in vitro, a penetração do H2O2 e a eficácia clareadora em dentes bovinos. Para isso, este estudo foi dividido em 2 partes. Parte 1: Segmento in vivo: 50 hemi-maxilas de 25 ratos foram divididas aleatoriamente em 5 grupos (n=10): Controle- não recebeu qualquer tratamento; CLA- recebeu 30 min do gel clareador H2O2 35%; BS-CLA- recebeu 20 min do gel de BS, seguido de 30 min do H2O2 35%; CLA+BS- recebeu 30 min de uma mistura do H2O2 35% com o gel BS (1:1); CLA+H2O- recebeu 30 min de uma mistura do H2O2 35% com água destilada (1:1). Após 2 dias, os animais foram mortos e as hemi-maxilas separadas para análise histológica em H.E. Foram atribuídos escores à inflamação e os dados submetidos aos testes de Kruskal-Wallis e Dunn e teste de Mann-Whitney (p<0,05). Segmento in vitro: 50 discos de dentes bovinos foram acoplados em câmaras pulpares artificiais, e divididos em 5 grupos (n=10) que receberam os mesmos tratamentos que o segmento in vivo. A penetração do H2O2 por esmalte e dentina foi quantificada baseada na reação deste com o corante violeta leucocristal. A alteração de cor foi analisada pelo sistema CIELab, nos períodos: ant... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: New products are being developed with the purpose of mitigating the effects of the compounds used in bleaching procedures. The objective of the present study was to evaluate in vivo the therapeutic potential of Biosilicate® (BS) gel on the pulp tissue of Wistar rats by means of histological and immunohistochemical analysis, as well as to analyze in vitro, the penetration of H2O2 and bleaching efficiency in bovine teeth. For this, this study was divided into 2 parts. Part 1: In vivo segment: 50 hemi-maxilla of 25 rats were randomly divided into 5 groups (n = 10): Control- received no treatment; CLA- received 30 min of the 35% H2O2 bleaching gel; BS-CLA- received 20 min of BS gel, followed by 30 min of 35% H2O2; CLA+BS- received 30 min of a mixture of 35% H2O2 with the BS gel (1:1); CLA+H2O- received 30 min of a mixture of 35% H2O2 with distilled water (1:1). After 2 days, the animals were killed and the hemi-maxils separated for histological analysis in H.E. Inflammation scores and data submitted to the Kruskal-Wallis and Dunn tests and Mann-Whitney test (p<0.05) were assigned. Segment in vitro: 50 discs of bovine teeth were coupled in artificial pulp chambers, and divided into 5 groups (n=10) that received the same treatments as the in vivo segment. The penetration of H2O2 by enamel and dentin was quantified based on the reaction of this with the leucocrystal violet dye. The color change was analyzed by the CIELab system, in the periods: before the bleaching session - (T0), i... (Complete abstract click electronic access below) / Mestre

Thesis (M.S.)--University of Michigan, 2005. / Includes bibliographical references.

Orientador: Alexandre Augusto Zaia / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Odontologia de Piracicaba / Made available in DSpace on 2018-08-04T20:03:13Z (GMT). No. of bitstreams: 1 Menini_MarceloOrlando_M.pdf: 529490 bytes, checksum: 1eb6bdfd00b70b948141086e3729d93a (MD5) Previous issue date: 2005 / Resumo: As dores de origem orofaciais associadas a problemas endodônticos, sejam de origem pulpar ou periapical, são uns dos mais importantes problemas dentro de um serviço de urgência odontológica. Portanto, um diagnóstico correto e tratamento eficaz nesses casos são imprescindíveis para eliminação da dor. O objetivo desse estudo foi avaliar o sucesso do atendimento de urgência endodôntica, realizado por alunos do 4º ano do curso de graduação, em 500 pacientes que procuraram o serviço de plantão de urgência da Faculdade de Odontologia de Piracicaba ¿ UNICAMP, no período de fevereiro de 2003 a maio de 2004. Foram incluídos casos de dor de origem dental, cujo diagnóstico foi confirmado como pulpite irreversível ou necrose pulpar associada à dor periapical, excluindo situação clínica de abscesso. O atendimento clínico de urgência foi realizado conforme preconizado pela disciplina de Endodontia da FOP-UNICAMP e nenhuma medicação foi prescrita aos pacientes. O controle do paciente foi realizado 24 horas após o atendimento, através de telefonema, onde o paciente relatava ausência ou presença de dor pós-operatória. Os resultados mostraram que o atendimento da urgência endodôntica realizado por alunos de graduação no serviço de plantão de urgência da FOP-UNICAMP, apresentou índice de sucesso de 92,6% / Abstract: Orofacial pain from pulpal and periapical disease is one of the most important problem in the emergencies services around the world. Therefore the correct diagnosis and treatment of the tooth are essential to decrease the patient¿s pain. The purpose of this study was to evaluate the success of endodontic emergency appointment in the eliminated of the pain, realized by graduated students in 500 patients, who were attended at the Emergency Service of the Piracicaba Dental School (State University of Campinas), with dental pain, diagnosted as irreversible pulpitis or apical pulp necrosis with periapical pain. The clinical appointment was realized in accord endodontic department of Piracicaba Dental School (State University of Campinas) and no medication was administrated. The follow up of patients was made 24 hours after, the appointment, by phone call, where patients related absence or presence of pain. The results showed that the endodontic emergency treatment, performed at Emergency Service of the Piracicaba Dental School (State University of Campinas) by graduated students had success in 92,6% of cases / Mestrado / Endodontia / Mestre em Clínica Odontológica

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