Thesis (M.S.)--University of Michigan, 1983.

Thesis (M.S.)--University of Michigan, 1996. / Includes bibliographical references.

Thesis (M.S.)--University of Michigan, 1983.

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Indiana University-Purdue University Indianapolis (IUPUI) / The functional quaternary ammonium salts (QAS) and their constructed polyQAS or PQAS were synthesized, characterized and formulated into a novel antibacterial glass-ionomer cement. Compressive strength (CS) and Streptococcus mutans (S. mutans) viability were used to evaluate the mechanical strength and antibacterial activity of the cements. Fuji II LC cement was used as control. The specimens were conditioned in distilled water at 37 oC for 24 h prior to testing. The effects of the substitute chain length, loading as well as grafting ratio of the QAS and aging on CS and S. mutans viability were investigated. Chapter 2 describes how we studied and evaluated the formulated antibacterial glass-ionomer cement by incorporating QAS chloride-containing polymer into the formulation. The results show that with PQAS addition, the studied cements showed a reduction in CS with 25-95% for Fuji II LC and 13-78% for the experimental cement and a reduction in S. mutans viability with 40-79% for Fuji II LC and 40-91% for the experimental cement. The experimental cement showed less CS reduction and higher antibacterial activity as compared to Fuji II LC. The long-term aging study indicates that the cements are permanently antibacterial with no PQAS leaching. Chapter 3 describes how we studied and evaluated the formulated antibacterial cements by changing chain length, type of halide, loading, grafting ratio and aging time. The results show that the effects of the chain length, loading and grafting ratio of the QAS were significant. Increasing chain length, loading, grafting ratio significantly enhanced antibacterial activity but reduced CS. The experimental cement showed less CS reduction and higher antibacterial activity as compared to Fuji II LC. The long-term aging study indicates that the cements are permanently antibacterial with no PQAS leaching. There was no significant difference between QAS bromide and QAS chloride, suggesting that we can use QAS bromide directly without converting bromide to chloride. In summary, we have developed a novel PQAS-containing antibacterial glass-ionomer cement. The cement has demonstrated significant antibacterial activities. Our experimental cement is a promising system because the reduced strength of the cement with addition of PQAS is still above those demonstrated by original commercial cement Fuji II LC without any PQAS addition. It appears that the experimental cement is a clinically attractive dental restorative that can be potentially used for long-lasting restorations due to its high mechanical strength and permanent antibacterial function.

Orientador: Cristiane Duque / Coorientador: Alberto Carlos Botazzo Delbem / Banca: Denise Pedrini / Banca: Thiago Cruvinel da Silva / Resumo: O objetivo deste estudo foi avaliar a influência da incorporação de nanopartículas de trimetrafosfato de sódio (TMP) e clorexidina (CHX) nas propriedades microbiológicas, físico-mecânicas e na capacidade de redução da desmineralização de um cimento de ionômero de vidro modificado por resina (CIV) indicado para restauração. Inicialmente, foram determinados nove grupos de estudo: 1) CIV; 2) CIV + CHX 1,25%; 3) CIV + CHX 2,5%; 4) CIV + TMP 7%; 5) CIV+ CHX 1,25% + TMP 7%; 6) CIV + CHX 2,5% + TMP 7%; 7) CIV+ TMP 14%; 8) CIV + CHX 1,25% + TMP 14%; 9) CIV + CHX 2,5% + TMP 14%. Para determinar a atividade antimicrobiana desses CIV contendo ou não TMP e CHX foi realizado o teste de difusão em ágar com Streptococcus mutans, Lactobacillus acidophilus, Actinomyces israelii e Candida albicans. Após 24h, os halos de inibição obtidos pelos CIV foram mensurados com o auxílio de um paquímetro digital. Corpos-de-prova dos CIV foram confeccionados utilizando matrizes específicas e avaliadas as seguintes propriedades físico-mecânicas para cada grupo de materiais do estudo: resistência à compressão e à tração diametral e dureza de superfície, além de determinar a liberação total de fluoreto (F) e de TMP. Foram preparados 80 blocos a partir de incisivos bovinos e selecionados pelo teste de dureza de superfície do esmalte (DS1). Os corpos-de-prova dos CIV foram adaptados aos blocos de esmalte recém-preparados e submetidos às ciclagens de pH. A seguir, foi analisada a dureza de superfície final do esmalte (DS2) para o cálculo da porcentagem da perda de dureza de superfície (%PDS) e verificar a capacidade do material em reduzir a desmineralização. Os dados foram submetidos aos testes de ANOVA e Bonferroni ou Student-Newman-Keuls, considerando p≤0,05. Os resultados mostraram que a adição... / Abstract: The aim of this study was to evaluate the influence of the association of sodium trimetaphosphate nanoparticles (TMP) and chlorhexidine (CHX) on the microbiological, physical-mechanical and enamel demineralization reduction of glass ionomer cement (GIC). Initially, nine groups of the study were defined: 1) control - GIC Fuji LII; 2) GIC+ 1.25% CHX; 3) GIC + 2.5% CHX; 4) GIC + 7%TMP; 5) GIC+ 1.25% CHX + 7%TMP; 6) GIC + 2.5% CHX + 7%TMP; 7) GIC+ 14%TMP; 8) GIC + 1.25% CHX + 14%TMP; 9) GIC+ 2.5% CHX + 14% TMP. The antimicrobial activity of GIC containing or not CHX/TMP was determined by agar diffusion test against Streptococcus mutans, Lactobacillus acidophilus, Actinomyces israelii and Candida albicans. After 24h, the inhibition zones obtained by the GIC were measured with a digital caliper. GIC specimens were prepared using specific stainless steel molds in order to evaluate the following physical-mechanical properties for each material group: compressive and diametral tensile strength and superficial hardness, besides to determine total fluoride and TMP release. Eighty enamel blocks were prepared from extracted bovine incisors and selected through the initial surface hardness test (SH1). GIC specimens were adjusted to the enamel blocks and submitted to pH-cyclings. After that, final superficial hardness (SH2) was determined in order to obtain the percentage of superficial hardness loss (%SHL) and observe the capacity of the materials in reducing enamel demineralization. Data were submitted to ANOVA and Bonferroni or Student-Newman-Keuls statistical tests, considering p≤0.05. The results showed that the addition of chlorhexidine increased the antimicrobial activity of GIC for all groups. The physical-mechanical properties of GIC, especially compressive strength, were jeopardized by the association... / Mestre

Orientador: André Luiz Fraga Briso / Coorientador: Paulo Henrique dos Santos / Banca: Ticiane Cestari Fagundes Tozzi / Banca: Anderson Catelan / Resumo: O objetivo neste estudo foi avaliar o efeito da contaminação do tecido dentinário e dos métodos normalmente empregados na limpeza do substrato sobre a resistência de união obtida na interface cimento de ionômero de vidro modificado por resina (CIVMR)/dentina. Para tanto, os 168 dentes bovinos foram desgastados até o tecido dentinário divididos em doze grupos (n=14), de acordo com o agente contaminante e a técnica de limpeza, sendo: NN - sem contaminação (N) e sem limpeza do substrato (N); NA - sem contaminação (N) e limpeza com spray ar/água (A); NP - sem contaminação (N) e limpeza com ácido poliacrílico 26% (P); SaN - contaminação por saliva (Sa) e sem limpeza do substrato (N); SaA - contaminação por saliva (Sa) e limpeza do substrato com spray ar/água (A); SaP - contaminação por saliva (Sa) e limpeza do substrato com ácido poliacrílico 26% (P); SgN - contaminação por sangue (Sg) e sem limpeza do substrato (N); SgA - contaminação por sangue (Sg) e limpeza do substrato com spray ar/água (A); SgP - contaminação por sangue (Sg) e limpeza do substrato com ácido poliacrílico 26% (P); HN - contaminação por agente hemostático (H) e sem limpeza do substrato (N); HA - contaminação por agente hemostático (H) e limpeza do substrato com spray ar/água (A); HP - contaminação por agente hemostático (H) e limpeza do substrato com ácido poliacrílico 26% (P). Todos os espécimes foram restaurados com o material ionomérico encapsulado Riva Light Cure (SDI) e, posteriormente foram obtidos palito... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: The objective of this study was to evaluate the effect of the contamination of the dentin tissue and the methods normally employed in the cleaning of the substrate on the bond strength obtained at the resin modified glass ionomer cement (RMGIC) / dentin interface. For this purpose, 168 bovine teeth were selected, which were worn to dentin tissue, and were then divided into twelve groups (n = 14), according to the contaminating agent and the cleaning technique: NN - without contamination (N) and without substrate cleaning (N); NW - no contamination (N) and spray / water cleaning (W); NP - without contamination (N) and cleaning with 26% polyacrylic acid (P); SaN - contamination by saliva (Sa) and without substrate cleaning (N); SaW - saliva contamination (Sa) and spray / water substrate cleaning (W); SaP - saliva contamination (Sa) and substrate cleaning with 26% polyacrylic acid (P); BN - blood contamination (B) and no substrate cleaning (N); BW - blood contamination (B) and cleaning the substrate with spray / water (W); BP - blood contamination (B) and substrate cleaning with 26% polyacrylic acid (P); HN - contamination by hemostatic agent (H) and without cleaning of the substrate (N); HW - hemostatic agent contamination (H) and spray / water substrate cleaning (W); HP - hemostatic agent contamination (H) and substrate cleaning with 26% polyacrylic acid (P). All specimens were restored with the Riva Light Cure (SDI) encapsulated ionomeric material and, afterwards, sticks of a... (Complete abstract click electronic access below) / Mestre

Thesis (M.S.)--West Virginia University, 2002. / Title from document title page. Document formatted into pages; contains vii, 101 p. : ill. (some col.). Vita. Includes abstract. Includes bibliographical references (p. 57-63).

published_or_final_version / Dentistry / Doctoral / Doctor of Philosophy

Thesis (M.S.)--The University of Michigan, 1986. / Also issued in print.