Comparative Analysis of AH Plus Bond Strength to Root Canal Dentin and Adhesive Interface Quality after Calcium Hydroxide Removal using Different Irrigation Protocols.

INTRODUCTION: To evaluate the push-out bond strength (POBS) of AH Plus sealer to root dentin and the adhesive interface quality after calcium hydroxide (Ca(OH)2) intracanal dressing removal with different final irrigation protocols. METHOD: After root canal instrumentation and irrigation, 40 root canals were filled with Ca(OH)2 and sealed. After 14 days, the specimens were randomly distributed according to the irrigation protocols for Ca(OH)2 removal (n = 10): GH2O (control) - distilled water; GNaOCl - 1% NaOCl; GEDTA - 17% EDTA; GEDTA + NaOCl - 17% EDTA + 1% NaOCl. The root canals were filled with AH Plus sealer and gutta-percha. After 7 days, the roots were sectioned into dentin slices and submitted to POBS test and analysis of the adhesive interface under scanning electron microscope. The POBS data were statistically evaluated (analysis of variance and Tukey test). The Kruskal-Wallis and Mann-Whitney tests were used to analyze the adhesive interface (α = 0.05). RESULTS: GH2O, GNaOCl, and GEDTA + NaOCl had similar POBS values, with higher values on the apical third, in comparison with other thirds (P < .05). A homogeneous and free-of-gaps adhesive interface was observed for GH2O, GNaOCl, and GEDTA + NaOCl, with difference between GH2O and GEDTA (P < .05). GH2O and GEDTA + NaOCl presented higher sealer tags formation (P < .05). CONCLUSION: The final rinse with EDTA for Ca(OH)2 dressing removal had a negative effect on the POBS of the filling material to root dentin. The use of EDTA followed by NaOCl had results similar to the distilled water, providing uniform and free-of-gaps adhesive interface, and a higher number of sealer tags.

Comparación de la actividad antimicrobiana de cementos selladores en endodoncia / Comparison of the antimicrobial activity of sealing cements in endodontics

Introducción: la persistencia de microorganismos en los conductos radiculares es uno de los principales factores del fracaso endodóncico. Por ello la importancia de conocer las propiedades antimicrobianas de los distintos tipos de selladores. Objetivo: realizar una comparación con base en la evidencia disponible sobre la actividad antimicrobiana de los diferentes cementos selladores en endodoncia. Material y métodos: la información fue recopilada de las bases de datos PubMed y Google Académico en el idioma inglés y español, publicados en el periodo 2014-2023. Resultados: un gran número de microorganismos se encuentran presentes en los diferentes tipos de infecciones de origen endodóncico, se han identificado más de 500 especies microbianas, entre ellas bacterias, hongos, arqueas y virus. Los cementos selladores se pueden clasificar según su composición química, en cementos a base de óxido de zinc-eugenol, hidróxido de calcio, a base de ionómero de vidrio, silicona, resina y biocerámicos. Conclusión: los cementos selladores que mostraron mayor actividad antimicrobiana contra los microorganismos persistentes fueron los cementos a base de óxido de zinc-eugenol, resina y biocerámicos. Sin embargo, se identificó que cada autor utilizó diferentes métodos y tiempos, por lo tanto, no es posible lograr definir con exactitud qué cemento sellador posee la mejor capacidad antimicrobiana (AU)

Introduction: the persistence of microorganisms in root canals is one of the main factors of endodontic failure. Therefore, the importance of knowing the antimicrobial properties of the different types of sealants. Objective: to make a comparison based on the available evidence on the antimicrobial activity of the different endodontics sealers. Material and methods: the information was collected from PubMed and Google Academic databases in English and Spanish, published in the period 2014-2023. Results: a large number of microorganisms are present in the different types of infections of endodontic origin, more than 500 microbiological species have been identified, including bacteria, fungi, archaea and viruses. Sealer cements can be classified according to their chemical composition, into cements based on zinc oxide-eugenol, calcium hydroxide, based on glass ionomer, silicone, resin and bioceramics. Conclusion: sealer cements that showed the highest antimicrobial activity against persistent microorganisms were zinc oxide-eugenol, resin, and bioceramic-based cements. However, it was identified that each author used different methods and times, therefore, it is not possible to accurately define which sealer cement has the best antimicrobial capacity (AU)

In Vitro Dental Discoloration Provoked by Intracanal Calcium Silicate-based Dressing Used for Regenerative Endodontic Procedures: An One-year Spectrometric Analysis.

INTRODUCTION: Regenerative endodontic procedures provide conditions for the continuity of apical formation and increase of the dentin wall thickness, being a useful technique to resume root development of necrotic teeth with incomplete apex. This study aimed to evaluate the coronal discoloration promoted by a new intracanal calcium silicate-based dressing and compare it with other intracanal dressings used in regenerative endodontic procedures. METHODS: Sixty bovine incisors were prepared to simulate teeth with incomplete apexes and divided according to the intracanal dressing used: triple antibiotic paste-double antibiotic paste-DAP, calcium hydroxide associated with 2% chlorhexidine gel, calcium hydroxide associated with saline solution, and Bio-C Temp. As control, no dressing was performed. The intracanal dressings remained in the simulated root canal for 21 days. Luminosity (ΔL) and color difference (ΔEab and ΔE00) were evaluated using long-term (1 year) spectrophotometric analysis. The results were analyzed using the ANOVA test with Tukey post hoc with a significance of 5%. RESULTS: Triple antibiotic paste showed the highest values of ΔEab and ΔE00 and lowest values of ΔL (P < .05). Bio-C Temp showed higher ΔEab than the other groups from 6 months (P < .05), higher ΔE00 and lower ΔL after 1 year (P < .05). CONCLUSIONS: Bio-C Temp induced noticeable coronary discoloration after the 1-year analysis.

Light-curing of calcium hydroxide-based liners: pH analysis and calcium ion release / Fotoativação de forradores a base de hidróxido de cálcio: análise de pH e liberação de íons cálcio

Objective: Compare the pH values and calcium ion release of calcium hydroxide-based liner materials before and after light-curing. Material and Methods: The materials evaluated were: hydrox-cal white (HW), hydrox-cal dentin (HD), Biocal (BC) and UltraBlend Plus (UB). 120 samples of the liner materials were inserted into a PVC tube (n=15). The samples from HW+A, HD+A, BC+A and UB+A were subjected to photoactivation. The other groups HW+N, HD+N, BC+N and UB+N were only inserted in a glass tube with deionized water. The pH was measured 24 hours and 14 days after the inclusion of the samples with the aid of a pH meter. The calcium release was analyzed with the aid of an atomic absorption spectophotometer at 24h and 14 days. The results were submitted to the Shapiro-Wilk test, followed by ANOVA and Tukey test (p=0.05). Results: In 24h, the groups that were not light cured showed the highest pH values (p<0.05). In 14 days, BC+N and BC+A demonstrated the lowest pH values. The groups that were not light cured also showed higher calcium release values in 24h and 14 days (p<0.05). Conclusion: Photoactivation of calcium hydroxide-based liner materials negatively interferes with calcium ion release, as well as with pH.(AU)

Objetivo: Comparar os valores de pH e liberação de íons cálcio de materiais forradores à base de hidróxido de cálcio antes e depois da fotopolimerização. Material e métodos: Os materiais avaliados foram: Hidrox-cal branco (HW), Hidrox-cal dentina (HD), Biocal (BC) e UltraBlend Plus (UB). 120 amostras dos materiais de revestimento foram inseridas em um tubo de PVC (n=15). As amostras de HW +A, HD+A, BC+A e UB+A foram submetidas à fotoativação. Os demais grupos HW +N, HD+N, BC+N e UB+N foram inseridos apenas em um tubo de vidro com água deionizada. O pH foi medido 24 horas e 14 dias após a inclusão das amostras com o auxílio de um medidor de pH. A liberação de cálcio foi analisada com o auxílio de um espectrofotômetro de absorção atômica em 24h e 14 dias. Os resultados foram submetidos ao teste de Shapiro-Wilk, seguido de ANOVA e teste de Tukey (p=0,05). Resultados: Em 24h, os grupos não fotopolimerizados apresentaram os maiores valores de pH (p<0,05). Em 14 dias, BC+N e BC+A apresentaram os menores valores de pH. Os grupos não fotopolimerizados também apresentaram maiores valores de liberação de cálcio em 24h e 14 dias (p<0,05). Conclusão: A fotoativação de materiais de revestimento à base de hidróxido de cálcio interfere negativamente na liberação de íons cálcio e no pH (AU)

Pulpectomies with Iodoform Versus Calcium Hydroxide-Based Paste: A Preliminary Randomised Controlled Clinical Trial

ABSTRACT Objective: To compare clinical and radiographical pulpectomy outcomes in primary teeth filled with different pastes. Material and Methods: The sample included thirty-eight teeth indicated for pulpectomy due to irreversible pulp inflammation or necrosis from thirty patients (2 to 9 years old). The first appointment comprised chemomechanical preparation (2.5% sodium hypochlorite), smear layer removal (6% citric acid), intracanal dressing and temporary restoration. Seven days later, teeth were randomly assigned to filling with iodoform (IP) or calcium hydroxide with zinc oxide (CHZO) based pastes and temporarily restored. Final restoration (composite resin) occurred at the 3rd appointment. Data from baseline, 6 and 12 months were analysed using descriptive and inferential statistics (p≤0.05). Results: The overall frequency of success was 63.6% (n=21), with no significant difference between groups (IP=62.5% n=10; CHZO=64.7% n=11, p=0.59). Multiradicular teeth, overfilled canals and teeth whose coronal restoration have been lost were significantly associated with failure (p=0.01, p=0.04 and p<0.001, respectively). Conclusion: After 12 months, both pastes showed similar outcomes and can be used as good options for pulpectomies in primary teeth. Moreover, tooth location, extent of the root canal filling, and integrity of final restoration during the follow-up influenced the outcome of pulpectomies.

Análise físico-química de balas duras e mastigáveis e o seu efeito desmineralizante em esmalte bovino / Physico-chemical analysis of hard and soft candies and their demineralizing effect in bovine enamel

Objetivo: avaliar o potencial cariogênico de balas duras e mastigáveis e seu potencial desmineralizante em esmalte bovino. Métodos: foram selecionadas 30 balas de diferentes marcas, divididas em balas duras (n=11), Tic Tac®, Halls® e IceKiss®, e balas mastigáveis (n=19), Lílith®, Azedinha®, Mentos Rainbow® e Dori Gomets®. As balas foram dissolvidas em água destilada (1:10) e foram avaliados pH, acidez titulável (ATT) e presença de sólidos solúveis totais (SST/°Brix). Na ciclagem erosiva, 40 espécimes de esmalte bovino foram divididos em quatro grupos (n=10): GCN ­ saliva artificial; GCP ­ ácido clorídrico; GT1 ­ solução da bala Lílith® maçã verde; GT2 ­ solução da bala IceKiss® extraforte. O desafio erosivo foi realizado por 2 minutos, 4x/dia, segui-do de 2 horas de imersão em saliva artificial durante cinco dias. Resultados: os valores de pH para as balas duras e mastigáveis variaram de 2,88 a 5,53 e de 2,73 a 4,16, respectivamente. ATT em pH 5,5 variou de 0,07 mL a 39,40 mL de NaOH 0,1 N, para as balas duras, e de 1,53 mL a 35,83 mL, para balas mastigáveis. ATT em pH 7,0 variou de 0,2 mL a 49,13 mL de NaOH, para balas duras, e de 2,37 mL a 49,97 mL, para as mastigáveis. O conteúdo de SST de todas as balas duras foi superior a 8,5°Brix, já entre as mastigáveis variou de 5,3 a 8,83°Brix. O GCP apresentou maior desmineralização que GCN e GT2 (p<0,05). Conclusão: a maioria das balas duras e mastigáveis dissolvidas em água destilada mostraram-se potencialmente erosivas e cariogênicas.(AU)

Objective: evaluate the cariogenic potential of hard and soft candies and their demineralizing potential in bovine enamel. Methods: 30 candies of different brands were selected, divided into hard candies (n=11): Tic Tac®, Halls® and IceKiss® and soft candies (n=19): Lílith®, Azedinha®, Mentos Rainbow® and Dori Gomets®. The candies were dissolved in distilled water (1:10) and pH, titratable acidity (TT) and presence of total soluble solids (SST/°Brix) were evaluated. In erosive cycling, 40 specimens of bovine enamel were divided into four groups (n=10): GCN - artificial saliva; GCP - hydrochloric acid; GT1 - Lilith® apple green candy solution; GT2 - IceKiss® Extra Strong candy Solution. The erosive challenge was performed for 2 minutes, 4X/day, followed by 2 hours of immersion in artificial saliva for five days. Results: pH values for hard and soft candies ranged from 2.88 to 5.53 and 2.73 to 4, respectively. ATT at pH 5.5 varied from 0.07 mL to 39.40 mL of 0.1 N NaOH for hard candies and 1.53 mL to 35.83 mL for soft candies. ATT at pH 7,0 varied from 0.2 mL to 49.13 mL of 0.1 N NaOH for hard candies and from 2.37 mL to 49.97 mL for soft candies. The content of SST of all hard candies was higher than 8.5 °Brix and for soft candies, varied between 5.3 to 8.83 °Brix. The GCP group showed greater demineralization than GCN and GT2 (p<0.05). Conclusion: most hard and soft candies dissolved in distilled water were potentially erosive and cariogenic.(AU)

Cytotoxic and genotoxic effects in human gingival fibroblast and ions release of endodontic sealers incorporated with nanostructured silver vanadate.

The cytotoxic and genotoxic effects of commercial endodontic sealers (AH Plus, Sealer 26 and Endomethasone N) incorporated with nanostructured silver vanadate decorated with silver nanoparticles (AgVO3 - at concentrations 2.5, 5, and 10%) on human gingival fibroblast (HGF), and the silver (Ag+ ) and vanadium (V4+ /V5+ ) ions release were evaluated. Cytotoxicity, cell death, and genotoxicity tests were carried out with extract samples of 24-hr and 7-days. The release of Ag+ and V4+ /V5+ was evaluated. Cytotoxicity in HGF was caused by AH Plus (AP) with 5 and 10% of AgVO3 (83.84 and 67.49% cell viability, respectively) with 24-hr extract (p < 0.05), as well as all concentrations of AP with 7-days extract (p < 0.05 -AP 0% = 73.17%; AP 2.5% = 75.07%; AP 5% = 70.62%; AP 10% = 68.46% cell viability). The commercial sealers Sealer 26 (S26) and Endomethasone N (EN) were cytotoxic (p < 0.05 - S26 0% = 34.81%; EN 0% = 20.99% cell viability with 7-days extract). AP 10% with 7-days extract induced 32% apoptotic cells in HGF (p < 0.05). Genotoxic effect was not observed. The AP groups released more Ag+ , while S26 and EN released more V4+ /V5+ in 24 hr. The Ag+ can be cytotoxic. In conclusion, the cytotoxicity caused to HGF can be attributed by the commercial sealers and enhanced by incorporation of AgVO3 , was not observed genotoxic effect, and apoptosis was induced only by AH Plus 10% 7-days extract. Ag+ can influence cell viability.

Durabilidade da união à dentina e liberação de cálcio promovidas por sistemas adesivos experimentais com adição de hidróxido de cálcio / Durability of the bond to dentin and calcium release promoted by experimental adhesive systems with the addition of calcium hydroxide

Objetivo: Este estudo investigou a liberação de cálcio (CaR) e estabilidade de adesão à dentina em longo prazo (DBS) de sistemas adesivos autocondicionantes experimentais contendo hidróxido de cálcio. Metodologia: Quatro sistemas adesivos foram formulados incluindo monômeros UDMA, HEMA, GDMA-P, TPO e difenil iodônio como sistema fotoiniciador, e etanol / água como solvente com diferentes frações de massa de hidróxido de cálcio: 0% (controle), 1%, 2% e 4%. O DBS foi medido pelo método de microtração de resistência de união em máquina de ensaio de microtração. O terço médio da dentina de 24 terceiros molares humanos (n = 6) foi usado para unir os sistemas adesivos a uma resina composta. Amostras em forma de palitos (1 mm2 ) foram obtidas após 24 horas de imersão em água destilada e testadas imediatamente e após 12 meses de armazenamento em água. Os dados foram avaliados estatisticamente por meio de ANOVA de dois fatores e pós-teste de Tukey (p <0,05). O CaR foi avaliado por meio de espectrofotômetro. Os espécimes em discos (6,0 mm de diâmetro x 0,3 mm de espessura) foram produzidos (n = 4) e imersos em água destilada. A concentração de cálcio foi medida após 3 h até 168 h. Resultados: Para DBS, os sistemas adesivos contendo 0%, 1% e 4% de hidróxido de cálcio apresentaram médias estatisticamente semelhantes entre os pontos de tempo imediato (24h) e 12 meses. O sistema adesivo contendo 2% de hidróxido de cálcio apresentou resistência de união estatisticamente maior em 12 meses (p = 0,001). Nenhum material liberou cálcio até 168 h após a fotoativação. Conclusão: A inclusão de hidróxido de cálcio a 2% resultou na melhora da durabilidade de união à dentina a longo prazo. No entanto, a inclusão de hidróxido de cálcio aos sistemas adesivos experimentais testados não foi capaz de liberar cálcio (AU).

Objective: This study investigated the calcium release (CaR) and long-term dentin bonding stability (DBS) of experimental self-etching adhesive systems containing calcium hydroxide. Methodology: Four adhesive systems were formulated including UDMA, HEMA, GDMA-P, TPO and diphenyl iodonium monomers as photoinitiator system, and ethanol/water as solvent with different mass fractions of calcium hydroxide: 0% (control), 1%, 2% and 4%. DBS was measured by the microtensile bond strength method in a microtensile testing machine. The middle third of dentin from 24 human third molars (n = 6) was used to bond the adhesive systems to a composite resin. Stick-shaped samples (1 mm2) were obtained after 24 hours of immersion in distilled water and tested immediately and after 12 months of storage in water. Data were statistically evaluated using two-way ANOVA and Tukey's post-test (p < 0.05). CaR was evaluated using a spectrophotometer. Disc specimens (6.0 mm in diameter x 0.3 mm thick) were produced (n = 4) and immersed in distilled water. Calcium concentration was measured after 3 h to 168 h. Results: For DBS, adhesive systems containing 0%, 1% and 4% calcium hydroxide had statistically similar means between the immediate time points (24h) and 12 months. The adhesive system containing 2% calcium hydroxide had a statistically higher bond strength in 12 months (p = 0.001). No material released calcium up to 168 h after photoactivation. Conclusion: The inclusion of 2% calcium hydroxide resulted in improved long-term bond strength to dentin. However, the inclusion of calcium hydroxide in the experimental adhesive systems tested was not able to release calcium (AU).

Effect of preheating on cytotoxicity and physicochemical properties of light-cured calcium-based cements.

The aim of this study was to evaluate the degree of conversion, cytotoxicity, solubility and pH of photopolymerizable calciumbased cements submitted to preheating. The degree of conversion was analyzed by Fourier transform infrared, cytotoxicity by the MTT test and solubility through loss of mass. The data were subjected to statistical tests (ANOVA / Tukey's, p<0.05). The photopolymerizable materials showed a low degree of conversion, regardless of preheating. All materials caused a reduction in cell viability at 24 hours and 7 days, with the Dycal (control) being more cytotoxic. Heat had a positive effect on Biocal at 7 days. Dycal is the most soluble material. Heat had no effect on the solubility or pH of the polymerizable materials. It is concluded that photopolymerizable calcium-based cements have a low degree of conversion and are soluble, which results in mild to moderate cytotoxicity.

O objetivo do presente estudo foi avaliar o grau de conversão, citotoxicidade, solubilidade e pH de cimentos à base de cálcio fotopolimerizáveis submetidos a pré-aquecimento. O grau de conversão foi analisado por espectroscopia no infravermelho com transformada de Fourier, a citotoxicidade pelo teste de MTT e a solubilidade através da perda de massa. Os dados foram submetidos a testes estatísticos (ANOVA/Tukey, p<0,05). Os materiais fotopolimerizáveis apresentaram baixo grau de conversão, independente do pré-aquecimento. Todos os materiais causaram redução da viabilidade celular nas análises de 24 horas e 7 dias, sendo que o Dycal (controle) apresentouse mais citotóxico e o calor apresentou efeito positivo sobre o Biocal na análise de 7 dias. O Dycal é o material mais solúvel e o calor não causou efeito na solubilidade e pH dos materiais polimerizáveis. Assim, conclui-se que os cimentos à base de cálcio fotopolimerizáveis apresentam baixo grau de conversão e são solúveis, que resulta em citotoxicidade suave e moderada.

Effect of preheating on cytotoxicity and physicochemical properties of light-cured calcium-based cements / Efeito do pré-aquecimento na citotoxicidade e propriedades físico-químicas de cimentos à base de cálcio fotopolimerizáveis

ABSTRACT The aim of this study was to evaluate the degree of conversion, cytotoxicity, solubility and pH of photopolymerizable calciumbased cements submitted to preheating. The degree of conversion was analyzed by Fourier transform infrared, cytotoxicity by the MTT test and solubility through loss of mass. The data were subjected to statistical tests (ANOVA / Tukey's, p<0.05). The photopolymerizable materials showed a low degree of conversion, regardless of preheating. All materials caused a reduction in cell viability at 24 hours and 7 days, with the Dycal (control) being more cytotoxic. Heat had a positive effect on Biocal at 7 days. Dycal is the most soluble material. Heat had no effect on the solubility or pH of the polymerizable materials. It is concluded that photopolymerizable calcium-based cements have a low degree of conversion and are soluble, which results in mild to moderate cytotoxicity.

RESUMO O objetivo do presente estudo foi avaliar o grau de conversão, citotoxicidade, solubilidade e pH de cimentos à base de cálcio fotopolimerizáveis submetidos a pré-aquecimento. O grau de conversão foi analisado por espectroscopia no infravermelho com transformada de Fourier, a citotoxicidade pelo teste de MTT e a solubilidade através da perda de massa. Os dados foram submetidos a testes estatísticos (ANOVA/Tukey, p<0,05). Os materiais fotopolimerizáveis apresentaram baixo grau de conversão, independente do pré-aquecimento. Todos os materiais causaram redução da viabilidade celular nas análises de 24 horas e 7 dias, sendo que o Dycal (controle) apresentouse mais citotóxico e o calor apresentou efeito positivo sobre o Biocal na análise de 7 dias. O Dycal é o material mais solúvel e o calor não causou efeito na solubilidade e pH dos materiais polimerizáveis. Assim, conclui-se que os cimentos à base de cálcio fotopolimerizáveis apresentam baixo grau de conversão e são solúveis, que resulta em citotoxicidade suave e moderada.

Effect of a calcium hydroxide-based intracanal medicament containing N-2-methyl pyrrolidone as a vehicle against Enterococcus faecalis biofilm.

INTRODUCTION: This study investigated the effect of a calcium hydroxide (CH) paste (CleaniCal®) containing N-2-methyl pyrrolidone (NMP) as a vehicle on Enterococcus faecalis (E. faecalis) biofilms compared with other products containing saline (Calasept Plus™) or propylene glycol (PG) (Calcipex II®). METHODOLOGY: Standardized bovine root canal specimens were used. The antibacterial effects were measured by colony-forming unit counting. The thickness of bacterial microcolonies and exopolysaccharides was assessed using confocal laser scanning microscopy. Morphological features of the biofilms were observed using field-emission scanning electron microscopy (FE-SEM). Bovine tooth blocks covered with nail polish were immersed into the vehicles and dispelling was observed. The data were analyzed using one-way analysis of variance and Tukey tests (p<0.05). RESULTS: CleaniCal® showed the highest antibacterial activity, followed by Calcipex II® (p<0.05). Moreover, NMP showed a higher antibacterial effect compared with PG (p<0.05). The thickness of bacteria and EPS in the CleaniCal® group was significantly lower than that of other materials tested (p<0.05). FE-SEM images showed the specimens treated with Calasept Plus™ were covered with biofilms, whereas the specimens treated with other medicaments were not. Notably, the specimen treated with CleaniCal® was cleaner than the one treated with Calcipex II®. Furthermore, the nail polish on the bovine tooth block immersed in NMP was completely dispelled. CONCLUSIONS: CleaniCal® performed better than Calasept Plus™ and Calcipex II® in the removal efficacy of E. faecalis biofilms. The results suggest the effect might be due to the potent dissolving effect of NMP on organic substances.

Antimicrobial activity of intracanal dressings composed by natural products associated to chlorhexidine and its influence on dentinal colour change / Avaliação da ação antimicrobiana de medicações intracanais à base de produtos fitoterápicos associados à clorexidina e sua influência na alteração de cor da estrutura dentinária

Purpose: evaluate the antimicrobial activity of intracanal dressings and their influence on dentinal colour changes. Material and methods: eighty single-rooted human extracted teeth were decoronated and divided into eight groups (n=10) according to intracanal dressing protocols inserted into the root canals: G1­distilled water (DW); G2­2% chlorhexidine gel (CHX); G3­calcium hydroxide (Ca[OH]2)+DW; G4­grape seed extract (GSE)+DW; G5­ginger extract (GE)+DW; G6­Ca(OH)2+CHX; G7­GSE+CHX; and G8­GE+CHX. The antimicrobial activity was evaluated by colony-forming units (CFUs) counting and dentinal colour changes was evaluated by digital spectrophotometry. Data were statistically analysed by One-way ANOVA followed by Tukey´s post hoc test (antimicrobial evaluation) and non-parametric Wilcoxon followed by the Mann- Whitney-U test (colour change evaluation) (α=0.05). Results: the highest bacterial reduction was observed in groups 4, 6, 7 and 8, with no significant difference between them (p<0.05). Groups 4 and 7 showed the highest medians of dentinal colour change (p<0.05). Conclusion: the addition of CHX improved the antimicrobial activity of GE-based intracanal dressing, with no effect in GSE-based intracanal dressing; moreover, these protocols induced significant dentinal colour changes. (AU)

Objetivo: avaliar a atividade antimicrobiana de medicações intracanais e sua influência na alteração da cor dentinária. Materiais e métodos: oitenta dentes humanos extraídos unirradiculares foram seccionados e divididos em oito grupos (n = 10), de acordo com os protocolos de medicação intracanal inseridos nos canais radiculares: água destilada G1 (DW); G2-2% de gel de clorexidina (CHX); hidróxido de cálcio G3 ­ (Ca [OH] 2) + DW; extrato de semente de uva G4 (GSE) + DW; extrato de gengibre G5 (GE) + DW; G6- Ca (OH) 2 + CHX; G7 ­ GSE + CHX; e G8-GE + CHX. A atividade antimicrobiana foi avaliada por contagem de unidades formadoras de colônias (UFCs) e as alterações de cor dentinária foram avaliadas por espectrofotometria digital. Os dados foram analisados estatisticamente por ANOVA one-way, seguida pelo teste post hoc de Tukey (avaliação antimicrobiana) e Wilcoxon não paramétrico, seguido pelo teste de Mann- Whitney-U (avaliação da mudança de cor) (α = 0,05). Resultados: a maior redução bacteriana foi observada nos grupos 4, 6, 7 e 8, sem diferença significativa entre eles (p < 0,05). Os grupos 4 e 7 apresentaram as maiores medianas da alteração da cor dentinária (p < 0,05). Conclusão: a adição de CHX melhorou a atividade antimicrobiana da medicação intracanal baseado em GE, sem efeito na medicação intracanal baseado em GSE; além disso, esses protocolos induziram alterações significativas na cor dentinária.(AU)

Characterization of novel calcium hydroxide-mediated highly porous chitosan-calcium scaffolds for potential application in dentin tissue engineering.

The aim of this study was to develop a highly porous calcium-containing chitosan scaffold suitable for dentin regeneration. A calcium hydroxide (Ca[OH]2 ) suspension was used to modulate the degree of porosity and chemical composition of chitosan scaffolds. The chitosan solution concentration and freezing protocol were adjusted to optimize the porous architecture using the phase-separation technique. Scanning electron microscopy/energy-dispersive spectroscopy demonstrated the fabrication of a highly porous calcium-linked chitosan scaffold (CH-Ca), with a well-organized and interconnected porous network. Scaffolds were cross-linked on glutaraldehyde (GA) vapor. Following a 28-day incubation in water, cross-linked CH scaffold had no changes on humid mass, and CH-Ca featured a controlled degradability profile since the significant humid mass loss was observed only after 21 (26.0%) and 28 days (42.2%). Fourier-transform infrared spectroscopy indicated the establishment of Schiff base on cross-linked scaffolds, along with calcium complexation for CH-Ca. Cross-linked CH-Ca scaffold featured a sustained Ca2+ release up to 21 days in a humid environment. This porous and stable architecture allowed for human dental pulp cells (HDPCs) to spread throughout the scaffold, with cells exhibiting a widely stretched cytoplasm; whereas, the cells seeded onto CH scaffold were organized in clusters. HDPCs seeded onto CH-Ca featured significantly higher ALP activity, and gene expressions for ALP, Col1, DMP-1, and DSPP in comparison to CH, leading to a significant 3.5 times increase in calcium-rich matrix deposition. In sum, our findings suggest that CH-Ca scaffolds are attractive candidates for creating a highly porous and bioactive substrate for dentin tissue engineering.

Effect of a calcium hydroxide-based intracanal medicament containing N-2-methyl pyrrolidone as a vehicle against Enterococcus faecalis biofilm

Abstract This study investigated the effect of a calcium hydroxide (CH) paste (CleaniCal®) containing N-2-methyl pyrrolidone (NMP) as a vehicle on Enterococcus faecalis (E. faecalis) biofilms compared with other products containing saline (Calasept Plus™) or propylene glycol (PG) (Calcipex II®). Methodology Standardized bovine root canal specimens were used. The antibacterial effects were measured by colony-forming unit counting. The thickness of bacterial microcolonies and exopolysaccharides was assessed using confocal laser scanning microscopy. Morphological features of the biofilms were observed using field-emission scanning electron microscopy (FE-SEM). Bovine tooth blocks covered with nail polish were immersed into the vehicles and dispelling was observed. The data were analyzed using one-way analysis of variance and Tukey tests (p<0.05). Results CleaniCal® showed the highest antibacterial activity, followed by Calcipex II® (p<0.05). Moreover, NMP showed a higher antibacterial effect compared with PG (p<0.05). The thickness of bacteria and EPS in the CleaniCal® group was significantly lower than that of other materials tested (p<0.05). FE-SEM images showed the specimens treated with Calasept Plus™ were covered with biofilms, whereas the specimens treated with other medicaments were not. Notably, the specimen treated with CleaniCal® was cleaner than the one treated with Calcipex II®. Furthermore, the nail polish on the bovine tooth block immersed in NMP was completely dispelled. Conclusions CleaniCal® performed better than Calasept Plus™ and Calcipex II® in the removal efficacy of E. faecalis biofilms. The results suggest the effect might be due to the potent dissolving effect of NMP on organic substances.

Cytotoxicity and biocompatibility of a new bioceramic endodontic sealer containing calcium hydroxide.

This study evaluated the cytotoxicity and biocompatibility of a new bioceramic endodontic sealer (i.e., Sealer Plus BC) in comparison with those of MTA Fillapex and AH Plus. L929 fibroblasts were cultured and Alamar Blue was used to evaluate cell viability of diluted extracts (1:50, 1:100, and 1:200) from each sealer at 24 h. Polyethylene tubes that were filled with material or empty (as a control) were implanted in the subcutaneous tissue of rats. The rats were killed after 7 and 30 d (n = 8), and the tubes were removed for histological analysis. Parametric data was analyzed using a one-way ANOVA test, and nonparametric data was analyzed via the Kruskal-Wallis test followed by the Dunn test (p < 0.05). A reduction in cell viability was observed in the extracts that were more diluted for Sealer Plus BC when compared to that of Control and AH Plus (p < 0.05). However, the 1:50 dilution of the Sealer Plus BC was similar to that of the Control (p > 0.05). Conversely, more diluted extracts of MTA Fillapex (1:200) and AH Plus (1:100 and 1:200) were similar to the Control (p > 0.05). Histological analysis performed at 7 d did not indicate any significant difference between tissue response for all materials, and the fibrous capsule was thick (p > 0.05). At 30 d, Sealer Plus BC was similar to the Control (p > 0.05) and MTA Fillapex and AH Plus exhibited greater inflammation than the Control (p < 0.05). The fibrous capsule was thin for the Control and for most specimens of Sealer Plus BC and AH Plus. Thus, Sealer Plus BC is biocompatible when compared to MTA Fillapex and AH Plus, and it is less cytotoxic when less-diluted extracts are used.

Endodontic Sealers Modified with Silver Vanadate: Antibacterial, Compositional, and Setting Time Evaluation.

The incorporation of nanoparticles into endodontic sealers aims at increasing antimicrobial activity of the original material. Aim. The aim of this study is to incorporate the nanostructured silver vanadate decorated with silver nanoparticles (AgVO3, at 2.5%, 5%, and 10%) into three endodontic sealers and evaluate the antibacterial activity of freshly sealers, surface topography and chemical composition, and setting time. Material and Methods. The AgVO3 was incorporated into AH Plus, Sealer 26, and Endomethasone N at concentrations 0%, 2.5%, 5%, and 10% (in mass). The antibacterial activity of freshly sealers was assessed by direct contact with Enterococcus faecalis and CFU/mL count (n=10), surface topography, and chemical composition were measured by SEM/EDS, and the setting time was measured by Gillmore needle (n=10). The Kruskal-Wallis and Dunn statistical tests were applied (α=0.05). Results. All groups of sealers evaluated inhibited E. faecalis (p>0.05). The incorporation of AgVO3 altered the atomic proportions between components of the endodontic sealers, and the percentage of silver (Ag) and vanadium (V) increased proportionally to the concentrations of AgVO3. Topography analysis showed differences in components distribution on the surface of the specimens. The sealers incorporated with AgVO3 of AH Plus presented a lower setting time than the control group (p<0.05). For Sealer 26 and Endomethasone N, the incorporation of AgVO3 increased the setting time in relation to control group (p<0.05). Conclusions. The modification of endodontic sealers by AgVO3 increased the atomic percentage of Ag and V proportionally to the concentration of the nanomaterial and changed the atomic percentage of the sealer components and setting times. It cannot be affirmed that the AgVO3 promote differences in the antimicrobial activity of freshly sealers, and further investigations of the antimicrobial activity of the set sealers should be carried out.

Comparison between calcium hydroxide mixtures and mineral trioxide aggregate in primary teeth pulpotomy: a randomized controlled trial.

OBJECTIVES: To evaluate the effect of calcium hydroxide (CH) associated with two different vehicles as a capping material for pulp tissue in primary molars, compared with mineral trioxide aggregate (MTA). METHODOLOGY: Forty-five primary mandibular molars with dental caries were treated by conventional pulpotomy using one of the following materials: MTA only (MTA group), CH with saline (CH+saline group) and CH with polyethylene glycol (CH+PEG group) (15 teeth/group). Clinical and periapical radiographic examinations of the pulpotomized teeth were performed 3, 6, and 12 months after treatment. Data were tested by chi-squared analysis and a multiple comparison post-test. RESULTS: The MTA group showed both clinical and radiographic treatment success in 14/14 teeth (100%), at all follow-up appointments. By clinical evaluation, no teeth in the CH+saline and CH+PEG groups had signs of mobility, fistula, swelling or inflammation of the surrounding gingival tissue. However, in the CH+saline group, radiographic analysis detected internal resorption in up to 9/15 teeth (67%), and inter-radicular bone resorption and furcation radiolucency in up to 5/15 teeth (36%), from 3 to 12 months of follow-up. In the CH+PEG group, 2/11 teeth (18%) had internal resorption and 1/11 teeth (9%) presented bone resorption and furcation radiolucency at all follow-up appointments. CONCLUSION: CH with PEG performed better than CH with saline as capping material for pulpotomy of primary teeth. However, both combinations yielded clinical and radiographic results inferior to those of MTA alone.

Influence of chlorhexidine and zinc oxide in calcium hydroxide pastes on pH changes in external root surface.

The objective of this study was to assess the influence of chlorhexidine (liquid and gel) and zinc oxide in calcium hydroxide (CH) pastes on root pH in simulated external resorption. One hundred human anterior teeth with a single root canal were selected. After decoronation and root canal instrumentation, the specimens were divided into 4 experimental groups and 1 control group (without intracanal paste): CH + saline (CH+S), CH + 2% chlorhexidine liquid (CH+ CHX), CH + 2% chlorhexidine gel (CH+ CHXg), and CH + 2% chlorhexidine gel + zinc oxide (CH+ CHXg+ZnO). pH was measured using a microelectrode at 3 and 24 h, and 1, 2, 3, and 4 weeks after inserting intracanal pastes. Data were analyzed statistically using an ANOVA and Tukey's test (p < 0.05). The CH+CHXg+ZnO group had the highest pH values throughout (p<0.05). The CH+S and CH+ CHX groups had the highest pH values after 1 week and the CH+ CHXg group after 2 weeks. CH+ CHXg maintained the highest pH until the fourth week compared with CH+ CHX (p < 0.05). The control group remained at a neutral pH at all evaluated times. It can be concluded that chlorhexidine solution or gel maintained the alkaline pH of CH, and chlorhexidine gel allowed a slower decrease in pH over time. CH+ CHXg+ZnO showed the highest pH values and was an effective intracanal medication for maintaining alkaline root pH in the area of resorption.

Cytotoxicity of intracanal dressings on apical papilla cells differ upon activation with E. faecalis LTA.

OBJECTIVE: The aim of this study was to investigate the cytotoxic effects of modified triple antibiotic paste and an experimental composition using calcium hydroxide on lipoteichoic acid (LTA)-primed apical papilla cells (APC). MATERIAL AND METHODS: Human APC were tested for in vitro cytotoxicity of modified Triple Antibiotic Paste (mTAP - Ciprofloxacin, Metronidazole and Cefaclor at 1:1:1) and of a paste of Ciprofloxacin, Metronidazole and Calcium hydroxide (CMC - 1:1:2) and modified CMC (mCMC - 2:2:1) by using MTT assay. The substances were reconstituted in DMEM at 1,000 µg/mL and » serially diluted before being kept in contact with cells for 1, 3, 5 and 7 days. Further, cells were primed with 1 µg/mL of Enterococcus faecalis LTA for 7 days prior to the viability test with 1,000 µg/mL of each substance. Statistical analysis was performed using one-way analysis of variance (ANOVA) and two-way ANOVA respectively followed by Tukey's post-test. Significance levels were set at p<0.05. RESULTS: In the first assay, the higher cytotoxic rates were reached by mTAP for all experimental periods. CMC was found toxic for APC at 5 and 7 days, whereas mCMC did not affect the cell viability. Only CMC and mCMC were able to induce some cellular proliferation. In the second assay, when considering the condition with medium only, LTA-primed cells significantly proliferated in comparison to LTA-untreated ones. At this context, mTAP and CMC showed similar cytotoxicity than the observed for LTA-untreated cells, while mCMC was shown cytotoxic at 7 days only for LTA-primed APC. Comparing the medications, mTAP was more cytotoxic than CMC and mCMC. CONCLUSION: mTAP showed higher cytotoxicity than CMC and mCMC and the effect of topic antimicrobials might differ when tested against apical papilla cells under physiological or activated conditions.

Influence of chlorhexidine and zinc oxide in calcium hydroxide pastes on pH changes in external root surface

Abstract The objective of this study was to assess the influence of chlorhexidine (liquid and gel) and zinc oxide in calcium hydroxide (CH) pastes on root pH in simulated external resorption. One hundred human anterior teeth with a single root canal were selected. After decoronation and root canal instrumentation, the specimens were divided into 4 experimental groups and 1 control group (without intracanal paste): CH + saline (CH+S), CH + 2% chlorhexidine liquid (CH+ CHX), CH + 2% chlorhexidine gel (CH+ CHXg), and CH + 2% chlorhexidine gel + zinc oxide (CH+ CHXg+ZnO). pH was measured using a microelectrode at 3 and 24 h, and 1, 2, 3, and 4 weeks after inserting intracanal pastes. Data were analyzed statistically using an ANOVA and Tukey's test (p < 0.05). The CH+CHXg+ZnO group had the highest pH values throughout (p<0.05). The CH+S and CH+ CHX groups had the highest pH values after 1 week and the CH+ CHXg group after 2 weeks. CH+ CHXg maintained the highest pH until the fourth week compared with CH+ CHX (p < 0.05). The control group remained at a neutral pH at all evaluated times. It can be concluded that chlorhexidine solution or gel maintained the alkaline pH of CH, and chlorhexidine gel allowed a slower decrease in pH over time. CH+ CHXg+ZnO showed the highest pH values and was an effective intracanal medication for maintaining alkaline root pH in the area of resorption.