Este ensaio clinico randomizado controlado avaliou a eficácia do uso da proteção pulpar indireta com cimento de hidróxido de cálcio (HC) ou sistema adesivo universal (AU) num período de seis meses de acompanhamento em lesões profundas de cáries em dentes permanentes após a remoção seletiva de tecido cariado (RSTC). Métodos: Participaram do estudo 48 pacientes, (mediana de idade de 27 anos [distribuição 7-54 anos]), com 41 molares e 15 premolares com lesões profundas de cárie (envolvimento radiográfico ≥50% de profundidade de dentina), sensibilidade pulpar positiva ao teste frio (gás refrigerado, -50°C, Maquira, PR, Brasil), ausência de dor espontânea, sensibilidade negativa aos testes de percussão, ausência de perda cuspídea e ausência de imagem radiográfica sugestiva de lesão periapical (radiografia periapical - VistaScan®). Após a remoção seletiva de tecido cariado para dentina amolecida, o grupo teste do ensaio recebeu um sistema adesivo universal (Universal single bond, 3M Espe, Brasil), enquanto o grupo controle recebeu a proteção pulpar indireta com cimento de hidróxido de cálcio (Dycal, Dentisply, Rj, Brasil). Todos os dentes foram imediatamente restaurados seguindo o condicionamento ácido seletivo em esmalte, aplicação de um sistema adesivo universal (AU) e resina composta nanoparticulada (Filtek Z350, 3M Espe, SP, Brasil). O desfecho de sucesso para vitalidade pulpar avaliou após seis meses: sensibilidade pulpar positiva ao teste frio, ausência de imagem sugestiva de lesão periapical (radiografia periapical - VistaScan®), ausência de dor espontânea e sensibilidade negativa à percussão vertical. Os dados foram submetidos à análise de sobrevida de Kaplan-Meier e teste Log Rank, e as variáveis idade (mediana), gênero, escolaridade, IPV, ISG, CPO-D, CPO-S, número de faces da restauração, tipo do dente, proteção pulpar indireta, profundidade da lesão (≥50% da profundidade da dentina ou ≥75% da profundidade da dentina) e presença de antagonista, quanto as suas distribuições nos dois grupos de tratamento pelos testes qui-quadrado e de Mann-Whitney. Resultados: As taxas de sucesso foram de 93.3% para o grupo controle (HC) e de 95.8% para o grupo teste (AU) (P=0.976). Dois casos de insucesso foram registrados, sendo necrose pulpar (grupo controle) e pulpite (grupo teste). As variáveis analisadas no início do estudo mostram uma amostra igualmente distribuída entre os grupos de tratamento. Nenhuma das variáveis foi relacionada ao insucesso. Os resultados sugerem que não há diferença entre o uso ou não de HC na proteção pulpar indireta após remoção 7 seletiva de tecido cariado em seis meses de acompanhamento, apresentando uma taxa de sucesso alta independente do tratamento. / This randomized controlled clinical trial evaluated the effectiveness of using indirect pulp protection with calcium hydroxide liner (CH) or universal adhesive (UA) over a period of 6 months in deep caries lesions on permanent teeth after selective removal to soft dentin (SCRSD). Methods: The sample consisted of 41 molars and 15 premolars (with radiographic involvement of the inner half of the dentin), from 48 patients, (median age 27 [distribution 7-54 years]), with positive response to cold test (refrigerated gas, -50 °C, Maquira, PR, Brazil), absence of spontaneous pain, negative sensitivity to percussion tests, absence of cuspid loss and absence of radiographic imaging suggestive of periapical lesion (periapical radiography). After the selective removal to soft dentin, the test group received a universal adhesive system (Universal Single Bond, 3M Espe, Brazil) whereas the control group received indirect pulp protection with calcium hydroxide liner (Dycal, Dentisply, Rj, Brazil). All teeth were restored following selective acid condition for enamel, adhesive system (UA) and nanoparticulate composite resin (Filtek Z350, 3M Espe, SP, Brazil). The successful outcome for pulp vitality assessed after six months: positive pulpal sensitivity to the cold test, absence of image suggestive of periapical lesion (periapical radiography - VistaScan®), absence of spontaneous pain and negative response to vertical percussion test. The results were submitted to the Kaplan-Meier survival analysis and the Log Rank test and the variables: age of subjects, gender, schooling, plaque index, gingival bleeding index, DMF-T, DMF-S, number of surfaces involved in the filling, type of the tooth, indirect pulp material, size of lesion (≥50% of dentine or ≥75% of dentine) and antagonist, analyzed for their distribution in the two treatment groups by the tests chi-square and Mann-Whitney. Results: The success rates were 93.3% for the control group (CH) and 95.8% for the test group (UA) (P=0,976). Only two cases of failure were recorded, one pulp necrosis (control group) and pulpitis (test group). The variables analyzed at the beginning of the study show a similarly distributed sample between treatment groups. The results suggest that there is no difference between the use of CH or UA in indirect pulp protection after SCRSD followed by composite restoration at six months of follow-up, showing a high rate of success for both treatments.

Orientador: Idomeo Bonetti Filho / Resumo: O objetivo deste estudo foi avaliar a eficiência de três métodos de remoção da medicação intracanal contendo hidróxido de cálcio(CH) com propilenoglicol(PG) e meticelulose(MC) e sua repercussão sobre a resistência de união e penetração de um cimento endodôntico (AH Plus) à dentina radicular. Inicialmente sessenta dentes unirradiculares foram preparados até o instrumento F5, em seguida foram divididos em 2 grupos(n=30) de acordo com o veículo(PG) e (MC). Após 7 dias, foram realizadas microtomografias dos espécimes, e mensurados a área total de preenchimento da medicação contendo hidróxido de cálcio no canal radicular. Em seguida os espécimes foram submetidos a três protocolos de remoção n=10: irrigação convencional(CI), irrigação ultrassônica passiva(PUI) e irrigação ultrassônica contínua(CUI) e uma nova análise microtomográfica foi realizada. A persistência dos resíduos HC (em mm3) foi avaliada após o uso dos protocolos de remoção. Em seguida os mesmos espécimes foram obturados com cimento endodôntico à base de resina epóxi associados com rodamina, e após a divisão em terços cervical, médio e apical, foram submetidos aos testes de push-out e posteriormente análise dos tipos de fratura e em seguida análise da penetração dentinária com microscopia a laser confocal. Houve similar persistência de resíduos de HC, independentemente do segmento analisado (P>0.05). Os valores obtidos no teste de push-out e penetração dentinária foram similar nos terços cervical e médio radicular (P >... (Resumo completo, clicar acesso eletrônico abaixo) / Doutor

This work aims on the investigation of factors influencing the discharge characteristicsof a heat storage system, which is based on the reversible reaction system of Ca(OH)2and CaO. As storage, a packed bed reactor with embedded plate heat exchanger forindirect heat transfer is considered. The storage system was studied theoretically bymeans of finite element analysis of a corresponding mathematical model. Parametricstudies were carried out to determine the influence of reactor design and operationalmode on storage discharge. Analysis showed that heat and gas transport throughthe reaction bed as well as the heat capacity rate of the heat transfer fluid affect thedischarge characteristics to a great extent. To obtain favourable characteristics interms of the fraction of energy which can be extracted at rated power, a reaction frontperpendicular to the flow direction of the heat transfer fluid has to develop. Such afront arises for small bed dimensions in the main direction of heat transport withinthe bed and for low heat capacity rates of the heat transfer fluid. Depending on thedesign parameters, volumetric energy densities of up to 309 kWh/m3 were calculatedfor a storage system with 10 kW rated power output and a temperature increase ofthe heat transfer fluid of 100 K. Given these findings, this study is the basis for thedimensioning and design of a pilot scale heat exchanger reactor and will help toevaluate the technical feasibility of thermo-chemical heat storage systems.

Introduction: The aim of this study was to evaluate the frequency and amount of Ca(OH)2 extrusion in relation to the intracanal delivery technique, apical foramen size, and depth of placement. Methods: Standardized training blocks with j-shaped canals were used (n=64); half of the simulated canals were shaped to apical size #35(.06 taper) and the remaining 32 to #45(.06). The frequency and extent of Ca(OH)2 extrusion were measured relative to apical taper, the depth of insertion, and whether syringe or spiral filler was used. Blocks were immersed in pH-sensitive gel and observed for color change. The visible extent of extrusion, indicated by color change, was determined as area and expressed in mm2. Results: Extrusion of Ca(OH)2 occurred in 48/64 of the samples. At 3mm from the canal terminus, the device type had a significant effect on the frequency of extrusion, with syringe placement causing extrusion significantly (p<0.01) more frequently, irrespective of device size. Amounts of extrusion were significantly larger at 2mm short of the canal terminus (median 27.44mm2, IQR 10.02), compared to 3mm distance (median 19.69mm2, IQR 25.07; p<0.0001). Analyzed separately at 2 and 3mm distance, respectively, there was significantly more extrusion with placement using a syringe size #35 compared to spiral filler size #45. Conclusions: Considering the limits of the in vitro experimental design, a spiral filler at 500rpm, placed 3mm short of the apex found to minimize extrusion of Ca(OH)2 placed in root canals.

Indiana University-Purdue University Indianapolis (IUPUI) / Background: Numerous studies have reported the effect of long-term use of calcium hydroxide Ca(OH)2 to dentin. Nevertheless, there is little information available about the effect of Ca(OH)2 on wettability to the dentin. Objective: To investigate the effect of Ca(OH)2 application on dentin for two and four weeks on the wettability of two root canal sealers. Methods: Polished caries-free human dentin discs (n = 156) were allocated into 12 groups; G1 and G3 had two weeks’ treatment, G4 and G6, four weeks treatment. G1 and 101 G4 were treated with sterile water. G2, G3, G5 and G6 were treated with Ca(OH)2. G1, G3, G4, and G6 were irrigated with 6.0-percent NaOCl and 17-percent EDTA while G2, and G5 were irrigated with sterile water. Then, contact angles between Tubli-Seal and the treated dentin surfaces were measured. G7 and G12 were treated in the same fashion but were treated with BC sealer. Surface morphology evaluation of G1 and G6 was carried out by scanning electron microscopy (SEM) and energy-dispersive x-ray spectroscopy (EDX). Statistics were performed using three-way ANOVA and pair-wise comparisons between groups (α = 0.05). Results: Tubli-Seal (G1 through G6) had significantly smaller values for contact angles than BC sealer (G7 through G12) (p < 0.05). For the Tubli-Seal groups (G1 through G6), G4 had the highest mean of contact angles at 104.9 ± 1.9°, whereas G5 presented the lowest mean of contact angles at 85.4 ± 15.1. For the BC sealer groups (G7 through G12), G10 had the highest mean of contact angles at 145.4 ± 1.3°, while G11 demonstrated the lowest mean of contact angles at 130.2 ± 2.6°. Groups with Ca(OH)2 treatment with water irrigation (G2, 5, 11) had significantly lower contact angle than groups with Ca(OH)2 with chemical irrigation (G3, 6, 12) (p < 0.05), except G8, 9. According to SEM and EDX, water irrigation solution showed higher remaining Ca(OH)2 than irrigation with the chemical solution while Ca(OH)2 with chemical irrigation 102 demonstrated no Ca(OH)2 remaining after irrigation, similar to the surface of the control group. Conclusion: Within the limitations of this study, Tubli-seal has better wettability on dentin than BC sealer. Remaining calcium hydroxide demonstrated a trend toward decreased contact angle between dentin and root canal sealers. Moreover, two-minute irrigation with 6-percent NaOCl and 17-percent EDTA can remove calcium hydroxide from polished dentin surfaces.

No description available.

Art conservation and restoration on ancient works are continuously involving new types of technologies. These trends are mostly taking place in Europe, especially Florence because it is the foremost leading city of art restoration, and has the most capable and devoted fresco restorers in Italy. This study contributes to the scholarly discourse of advances in art restoration involving computers and nanotechnology, and promotes the use of technology in the field of art. The crux of the paper focuses on the Brancacci Chapel fresco cycle restoration throughout the span of several years. This project is important to the research of art restoration primarily because it has undergone several different methods of repair. This is probably due to the fact that the chapel was subject to a fire in 1771 t as well as the Florence flood of 1966. This thesis examines the different viewpoints of art scholars regarding the implementation of nanoscicence and computers in the field and sheds light on restorations done on recent works and the incorporation of nanotechnology in American museums.

No / Produttion control methods allow factory produced mortars to be supplied to a more consistent formulation than site produced mortars. However, there is scope to enhance their "sustainability" credentials by addressing the methods of drying the wet sand and the use of lower energy hydraulic components. This paper describes the development of a technique in which quicklime is added in controlled quantities to remove free water by both chemical combination and evaporation. The slaked lime so generated is porous and a third mechanism of absorption is suggested which, however, might have adverse effects during storage of the pre-blended mortar. The principal process-control factors are lime addition based upon a ratio of the stoichiometric requirements for complete slaking of the quicklime, free moisture content of the sand, mixing time of the combined sand and quicklime, and storage of the mixed material. (C) 2015 Elsevier Ltd. All rights reserved.

Indiana University-Purdue University Indianapolis (IUPUI) / Endodontic regeneration treatment of necrotic immature teeth has gained popularity in recent years. The approach suggests a biological alternative to induce a continuous root development. In this project, three in vitro experiments were conducted to investigate the effect of three medicaments used in endodontic regeneration on mechanical properties and chemical structure of radicular dentin. In the first experiment, we investigated longitudinally the effect of medicaments on the indentation properties of the root canal surface of immature teeth using a novel BioDent reference point indenter. A significant difference in the majority of indentation parameters between all groups was found after one-week and one-month application of medicaments (p<0.0001): triple antibiotic paste (TAP) > double antibiotic paste (DAP) > control > calcium hydroxide [Ca(OH)2]. The four-week exposure of dentin to TAP and DAP caused 43% and 31% increase in total indentation distance outcome, respectively. In the second experiment, we investigated longitudinally the effect of medicaments on the chemical structure of immature radicular dentin by measuring the phosphate/amide I ratios of dentin using Attenuated Total Reflection Fourier Transform Infrared Spectroscopy. Phosphate/amide I ratios were significantly different between the four groups after one week, two weeks and four week application of medicaments (p<0.0001): Ca(OH)2-treated dentin > untreated dentin > DAP-treated dentin > TAP-treated dentin. In the third experiment, we investigated longitudinally the effect of medicaments on root fracture resistance and microhardness of radicular dentin. For the microhardness, the two-way interaction between group and time was significant (p<0.001). TAP and DAP caused a significant and continuous decrease in dentin microhardness after one and three month application, respectively. The three-month intracanal application of Ca(OH)2 significantly increased the microhardness of root dentin. The time factor had a significant effect on fracture resistance (p<0.001). All medicaments caused significant decrease in fracture resistance ranging between 19%-30% after three month application compared to one week application. The three medicaments used in endodontic regeneration caused significant change in the chemical integrity of the superficial radicular dentin and significantly affected the indentation properties of the root canal surface. Furthermore, the three month intracanal application of medicaments significantly reduced the fracture resistance of roots.

O sucesso da terapia endodôntica depende da limpeza, anti-sepsia, escultura e obturação hermética dos canais radiculares, no entanto, o preparo biomecânico não gera redução microbiana suficiente na totalidade dos casos. Devido à inconfiabilidade inerente ao tratamento, parte dos casos ainda resulta em insucesso. As pastas de hidróxido de cálcio vêm sendo empregadas com a finalidade de ampliar a eficiência anti-séptica do tratamento dos canais radiculares além de estimular a recuperação dos tecidos afetados pela infecção endodôntica. O digluconato de clorexidina tem sido empregado na endodontia devido ao amplo espectro de ação principalmente contra \"Enterococcus faecalis\" e \"Candida albicans\" e vem sendo adicionado às pastas de hidróxido de cálcio uma vez que as virtudes de um complementam as deficiências do outro. No entanto, devido à estrutura molecular da clorexidina e aos níveis elevados de pH promovidos pelo hidróxido de cálcio, há indícios de risco sistêmico na sua utilização por causa da provável decomposição da clorexidina em radicais livres e para-cloroanilina que está classificada como possível agente carcinogênico em humanos pela IARC. O presente estudo teve como objetivo investigar quimicamente, por meio da Espectrometria de Massas (ESI-TOF-MS) e Cromatografia Líquida (HPLC), a solução de digluconato de clorexidina a 0,2% isolada ou misturada ao hidróxido de cálcio. As análises foram realizadas logo em seguida ao preparo das amostras e após os períodos de 7 e 14 dias de armazenamento à temperatura de 36,5 ºC. Constatou-se que a solução de digluconato de clorexidina isolada foi decomposta em diferentes subprodutos, inclusive em para-cloroanilina oferecendo riscos sistêmicos. Em contato com o hidróxido de cálcio, a decomposição da clorexidina é total com formação de diferentes compostos. Apesar de não ter sido demonstrada a presença de para-cloroanilina na pasta medicamentosa, o elevado número de espécies reativas possui alto potencial de dano sobre o material genético das células do paciente afetadas pela medicação intracanal. É imperativo estabelecer vínculos diagnóstico-terapêuticos precisos por meio do desenvolvimento de protocolos clínicos que restrinjam o uso dessas medicações intracanais a quadros clínicos com infecção endodôntica disseminada e periodontites apicais persistentes. É necessário desenvolver estratégias mais eficientes que utilizem processos biomecânicos de maior eficácia e medicações intracanais efetivas que não ofereçam riscos locais e sistêmicos para que se contemplem os objetivos do tratamento dos canais radiculares com previsibilidade e segurança. / The success of endodontic therapy depends upon root canal cleanliness, antisepsis, sculpture, and hermetic obturation. However, biomechanical preparation does not always provide an adequate microbial reduction. Due to the inherent unreliability of the treatment, some cases still are unsuccessful. Calcium hydroxide pastes have been used with the aim to improve antisepsis effectiveness in root canal treatments, in addition to stimulating the recovery of tissues affected by endodontic infection. Chlorhexidine digluconate has been used in endodontics due to its broad action spectrum, mainly against \"Enterococcus faecalis\" and \"Candida albicans\", and has been added to calcium hydroxide pastes so that the advantages of one would compensate for the other\'s deficiencies. However, the structure of the chlorhexidine molecule in addition to the high pH values promoted by calcium hydroxide pose a systemic risk in its use due to the likely decomposition of chlorhexidine into free radicals and para-chloroaniline, which International Agency for Research on Cancer (IARC) has classified as a possible carcinogenic agents in humans. The purpose of the present study was to perform a chemical analysis of chlorhexidine digluconate at 0.2%, isolated or mixed to calcium hydroxide, using Mass Spectrometry and High- Efficiency Liquid Chromatography. The analyses were performed shortly after the samples were prepared, and after 7 and 14 days of storage at 36.5 ºC. It was found that the isolated chlorhexidine digluconate solution formed different byproducts, including para-chloroaniline, posing systemic risks. In contact with calcium hydroxide, chlorhexidine decomposes completely and forms different compounds. Though the study did not demonstrate the presence of para-chloroaniline in the medication paste, the high number of reactive species poses a high risk over the genetic material of the host cells affected by intracanal medication. It is mandatory to establish a precise diagnostic-therapeutic relation by developing clinical protocols that would restrict the use of these intracanal medications to clinical conditions with disseminated endodontic infection and persistent apical periodontitis. There is a need for more efficient strategies that use more effective biomechanical processes and intracanal medications that do not offer any local or systemic risk so root canal treatment goals can be considered with predictability and safety.