Biocompatibility, Biomineralization and Induction of Collagen Maturation with the Use of Calcium Hydroxide and Iodoform Intracanal Dressing.

Biocompatibility and biomineralization of root canal dressings are important requirements for periapical healing. This study evaluated the inflammatory response, biomineralization and tissue repair by collagen fiber maturation in the subcutaneous tissue of rats. Eighteen Wistar rats (n = 6) received subcutaneous implants: calcium hydroxide + propylene glycol [CH+P], calcium hydroxide + propylene glycol + iodoform [CH+P+I], iodoform + carbowax [I+Cwax] and carbowax [Cwax]. Extra empty tubes were used as a control [C]. After 7, 15 and 30 days, the implants were removed with surrounding tissue for staining of hematoxylin-eosin, Von Kossa, picrosirius red and without staining for analysis under polarized light. Results were analyzed via Kruskal-Wallis followed by Dunn testing for nonparametric data and ANOVA followed by a Tukey post hoc test for parametric data (p < 5%). At 7 days, all groups showed a moderate inflammatory reaction and thick fibrous capsule, except the [Cwax] group, with a severe inflammatory infiltrate (p < 0.05). After 15 days, all groups but control had a decrease in inflammatory response. At 30 days, all groups presented a mild reaction and thin fibrous capsule (p > 0.05). Only groups containing calcium hydroxide were found to be positive using Von Kossa staining and polarized light in all periods. At 7 days, all groups showed a higher proportion of immature fibers. At 15 days, the [CH+P] and [Cwax] groups increased their proportion of mature/immature fibers. At 30 days, only the [CH+P] group presented a significant prevalence of mature collagen fibers (p < 0.05). All groups showed biocompatibility, but only groups containing calcium hydroxide induced biomineralization. The addition of iodoform delayed tissue healing.

An Epigallocatechin-3-gallate Formulation Developed for Endodontic Use: A Physicochemical and Biological Evaluation.

INTRODUCTION: Although epigallocatechin-3-gallate (EGCG) from green tea has been successfully used in the prevention and treatment of several infectious and immunoinflammatory diseases because of its proven anti-inflammatory, antioxidant, antimicrobial, and antiresorptive role, its use as an intracanal dressing has not been proposed. The aim of this study was to develop a formulation based on EGCG for endodontic use by assessing its physicochemical and biological properties. METHODS: Initially, physicochemical characterization of EGCG was performed by ultraviolet-visible and fluorescence spectroscopy to evaluate if the properties were maintained in acidic pH and time (1-6, 24, and 27 hours). After that, biological studies evaluated the developed formulation of EGCG at different concentrations (1.25, 5, 10, and 20 mg/mL). The tissue compatibility with subcutaneous tissue of mice was evaluated by plasma leakage after 24 hours and the examination of macroscopic and microscopic features at 7, 21, and 63 days after the insertion of polyethylene tubes containing the formulations. The repair of experimentally induced periapical lesions in dog's teeth by radiographic and histopathologic analysis was also evaluated. The scores were statistically analyzed by the chi-square and Fisher exact test. Analysis of variance followed by the Tukey posttest were used for the quantitative analysis. The significance level was 5%. RESULTS: The physicochemical characterization performed under ultraviolet-visible spectrophotometry showed that the EGCG properties remained unaltered in acid pH and function of time, keeping its wavelength to 274 nm. Macroscopic parameters evaluated at 7, 21, and 63 days showed that all concentrations presented no epithelial ulceration or presence of mild superficial tissue necrosis, edema, or vascularization with no significant difference in the control group. During all periods of microscopic examination, all groups presented the absence of abscess foci and edema and the presence of fibrous capsule and neovascularization. The presence of reparative tissue with a gentle presence of neutrophilic inflammatory cells was also observed for all groups, except for the calcium hydroxide paste group, which presented a more pronounced inflammation and tissue necrosis at days 7 and 21 (P < .001). At day 63, all groups presented an absence of inflammatory infiltrate and necrosis. The evaluation of dog teeth showed that treatment with the EGCG formulation provided a reduction of the periapical radiolucent area and allowed the repair of apical and periapical tissues (P > .05). CONCLUSIONS: The developed formulation based on EGCG from green tea presented physicochemical stability and tissue compatibility and provided the repair of periapical lesions when used as an intracanal dressing.

Effectiveness of grape seed extract-based intracanal dressings against Enterococcus Faecalis and its influence on dentin microhardness and bond strength of filling material / Eficácia de medicamentos intracanais à base de extrato de semente de uva contra o Enterococcus Faecalis e sua influência na micro-dureza da dentina e na resistência de união do material obturador

The aim of this study was to evaluate the effectiveness of grape seed extract (GSE)-based intracanal dressings against Enterococcus faecalis (E. faecalis) and its influence on dentin microhardness and bond strength of the filling material. The root canals of 126 human teeth were distributed into three test groups: antimicrobial activity (60 teeth), dentin microhardness (30 teeth) and bond strength (36 teeth). In all three groups, specimens were subdivided into six groups, according to intracanal dressing protocols: G1 ­ distilled water (DW); G2 ­ 2% chlorhexidine gel (CHX); G3 ­ calcium hydroxide (Ca[OH]2)+DW; G4 ­ GSE+DW; G5 ­ Ca(OH)2+CHX; G6 ­ GSE+CHX. The counting of colony-forming units (CFUs), the Vickers microhardness tester and the push-out test were performed to evaluate the antimicrobial activity, dentin microhardness and bond strength, respectively. Specific statistical analysis was performed for each evaluation (α=5%). The greatest bacterial reduction was observed in G5 (Ca[OH]2+CHX) and G6 (GSE+CHX) (p<0.05). There was no statistically significant difference among groups in the dentin microhardness evaluation (p<0.05). The highest bond strength in the immediate evaluation was observed in G4 (GSE+DW) and G6 (GSE+CHX), whereas the highest bond strength after 12 months of storage was observed in G2 (CHX), G3 (Ca[OH]2+DW), G4 (GSE+DW), and G6 (GSE+CHX) (p<0.05). After the storage period, bond strength was increased in G2 (CHX) and G3 (Ca[OH]2+DW), and remained unchanged in G4 (GSE+DW) and G6 (GSE+CHX) (p<0.05). GSE-based intracanal dressings have antimicrobial potential against E. faecalis, have no influence in dentin microhardness and preserve the high bond strength of filling materials for root dentin over time.

O objetivo deste estudo foi avaliar a eficácia de medicamentos intracanal à base de extrato de semente de uva (GSE) contra Enterococcus faecalis (E. faecalis) e sua influência na microdureza da dentina e na resistência de união do material de obturação. Os canais radiculares de 126 dentes humanos foram distribuídos em três grupos de teste: atividade antimicrobiana (60 dentes), microdureza da dentina (30 dentes) e resistência adesiva (36 dentes). Nos três grupos, as amostras foram subdivididas em seis grupos, de acordo com os protocolos de curativos intracanal: G1 ­ água destilada (DW); G2 ­ gel de clorexidina a 2% (CHX); G3 ­ hidróxido de cálcio (Ca[OH]2) +DW; G4 ­ GSE+DW; G5 ­ Ca(OH)2+CHX; G6 ­ GSE+CHX. A contagem de unidades formadoras de colônias (UFCs), o testador de microdureza Vickers e o teste push-out foram realizados para avaliar a atividade antimicrobiana, a microdureza da dentina e a resistência adesiva, respectivamente. Análise estatística específica foi realizada para cada avaliação (α=5%). A maior redução bacteriana foi observada no G5 (Ca[OH]2+CHX) e G6 (GSE+CHX) (p<0,05). Não houve diferença estatisticamente significativa entre os grupos na avaliação da microdureza da dentina (p<0,05). A maior resistência adesiva na avaliação imediata foi observada no G4 (GSE+DW) e G6 (GSE+CHX), enquanto a maior resistência adesiva após 12 meses de armazenamento foi observada no G2 (CHX), G3 (Ca[OH]2+DW), G4 (GSE+DW) e G6 (GSE+CHX) (p<0,05). Após o período de armazenamento, a resistência de união aumentou no G2 (CHX) e G3 (Ca[OH]2+DW), permanecendo inalterada no G4 (GSE+DW) e G6 (GSE+CHX) (p<0,05). Os medicamentos intracanal à base de GSE têm potencial antimicrobiano contra E. faecalis, não influenciam na microdureza da dentina e preservam a alta resistência adesiva dos materiais de obturação da dentina radicular ao longo do tempo.

Alkalizing potential and calcium release of residues from intracanal dressing containing calcium hydroxide / Potencial de alcalinização e liberação de cálcio de resíduos de medicação intracanal contendo hidróxido de cálcio

Introduction: If the restoration, that seal the root canal from oral environment, failed or solubilize, the intracanal dressing could be partially removed, decreasing the efficiency of calcium hydroxide (CH). Objective: To evaluate the alkalizing potential and calcium ions release of intracanal residues from different medications, in different periods. Materials and method Human incisors were endodontically instrumented and randomly divided (n=10). The root canals were filled with: G1- Calcium hydroxide (CH); G2- CH with 0.4% chlorhexidine digluconate (CHC); G3 - CH with camphorated paramonochlorophenol and glycerin (HPG); G4 - CH was maintained during all experiment, as positive control group (PC) and G5 - No medication was performed in the negative control group (NC). The specimens were immersed in distilled water for 7 days. The intracanal dressing was removed from the experimental groups using F1 instrument (Protaper). The teeth were stored in distilled water for 24 hours, 7, 14 and 28 days. pH value and calcium ions released were evaluated and the data were submitted to ANOVA one-way and Tukey tests. Result All experimental groups presented lower alkalizing potential and calcium ions release than PC (P < 0.05). No significant difference was found among the experimental groups, regardless of the period (P > 0.05). Conclusion The alkalizing potential and calcium ions release of residues from different intracanal dressing, in different periods, were similar and lower than the positive control group, that the medication was maintained inside the root canal, encouraging the replacement of intracanal dressing when the restoration fail.

Introdução: Se a restauração temporária, que sela o canal radicular contra o meio bucal, falhar ou solubilizar, a medicação intracanal pode ser parcialmente removida, diminuindo a eficiência do hidróxido de cálcio (CH). Objetivo: Avaliar o potencial alcalinizante e a liberação de íons cálcio de resíduos de diferentes medicações intracanal, em diferentes períodos. Material e método: Incisivos humanos foram endodonticamente instrumentados e divididos aleatoriamente (n=10). Os canais radiculares foram preenchidos com: G1-Hidróxido de cálcio (CH); G2-CH com 0.4% de digluconato de clorexidina (CHC); G3-CH com paramonoclorofenol camforado e glicerina (HPG); G4-CH mantido durante todo experimento, como controle positivo (PC) e G5- Sem medicação intracanal, como controle negativo (NC). Os espécimes foram imersos em água destilada durante 7 dias. A medicação intracanal foi removida dos grupos experimentais com um instrumento F1 (Protaper). Os dentes foram armazenados em água destilada por 24 horas, 7, 14 e 28 dias. Os dados foram submetidos aos testes ANOVA one-way e Tukey. Resultado: Todos os grupos experimentais tiveram redução no potencial alcalinizante e na liberação dos íons cálcio, quando comparados ao controle positivo (p<0.05). Não houve diferença estatisticamente significante entre os grupos experimentais, independente do período (p>0.05). Conclusão: O potencial alcalinizante e a liberação de íons cálcio dos resíduos de diferentes medicações intracanal, em diferentes períodos, foram similares entre si e menores que o controle positivo, onde a medicação foi mantida dentro do canal radicular, encorajando a sua troca quando a restauração falhar.

Removal of calcium hydroxide from Weine Type II systems using photon-induced photoacoustic streaming, passive ultrasonic, and needle irrigation: a microcomputed tomography study

ABSTRACT Objective This study compared the effectiveness of Er:YAG laser-activated irrigation (PIPS), passive ultrasonic irrigation (PUI) with EndoUltra and standard needle irrigation (SNI) in the removal of calcium hydroxide [Ca(OH)2] from the mesial roots of Weine Type II mandibular molars. Material and Methods Thirty mandibular molars were screened by µCT for the presence of mesial roots with complex intra-canal anatomy and a common apical foramen. The teeth were enlarged to a standardized 25/.06 preparation and filled with Ca(OH)2 paste. Specimens were divided into three groups (n=10) according to the technique used for Ca(OH)2 removal: PIPS, at 15 Hz and 20 mJ using a 9 mm long, 600 µm diameter tip; PUI using a 15/.02 tip; and SNI (30 Ga. side-vented needle). Equal volumes of 8.25% NaOCl and 17% EDTA were used in all groups. µCT was used to measure the initial amount of Ca(OH)2 present and to assess the residual volume of Ca(OH)2 following each irrigation protocol. Data were analyzed using Tukey HSD and Kruskal-Wallis tests (α=5%). Results The mean volume of Ca(OH)2 before removal was significantly higher in the coronal third than in the middle and apical third (p<0.001). Ca(OH)2 was similarly removed from the coronal and middle thirds with the three methods used (p>0.05). PIPS (median 0%; IQR: 0-0) showed significant higher Ca(OH)2 removal in the apical third than PUI (median 100%, IQR: 85-100) and SNI (median 47%; IQR: 16-72) (p<0.001). Conclusions PIPS laser-activation was more effective for the removal of Ca(OH)2 from mesial roots of mandibular molars with Weine Type II canal configurations than PUI with EndoUltra and SNI.

Cysteamine Enhances Biofilm Eradication Efficacy of Calcium Hydroxide.

INTRODUCTION: Calcium hydroxide (Ca[OH]2) is a widely used interappointment dressing, but its antibacterial property is compromised by dentin. Hence, the addition of chlorhexidine (CHX) with Ca(OH)2 has been proposed. However, the antimicrobial efficacy of this mixture compared with Ca(OH)2 alone is currently still debatable. Cysteamine is a mucolytic agent used to reduce the viscosity of mucus through the disruption of proteins, which are also important components of the extracellular matrix of biofilms. The aims of this study were to determine the efficacy of cysteamine alone and in combination with Ca(OH)2 to eradicate Enterococcus faecalis biofilm compared with CHX with Ca(OH)2, and to determine if this effect is affected by dentin. METHODS: The biofilm eradication efficacies of Ca(OH)2 alone and with cysteamine were determined using 7-day E. faecalis biofilm cultured on dentin discs and compared with Ca(OH)2 with 2% CHX. The effects of dentin on the efficacies of Ca(OH)2 alone and with either cysteamine or CHX were examined. RESULTS: Cysteamine alone completely abolished E. faecalis biofilm at 200 mg/mL. The combination of Ca(OH)2 with either cysteamine at 10 mg/mL or 2% CHX completely obliterated E. faecalis biofilm. Cysteamine with Ca(OH)2 completely eradicated E. faecalis biofilm despite preincubation with dentin, whereas CHX with Ca(OH)2 was less effective. CONCLUSIONS: Cysteamine effectively eliminated E. faecalis biofilm and showed synergistic effects in combination with Ca(OH)2, which were unaffected by dentin. Hence, our findings support the use of cysteamine as a potential adjunct to Ca(OH)2 as an interappointment dressing.

Avaliação do hidróxido de cálcio associado à própole com agitação ultrassônica como curativo intracanal em reimplante dentário tardio / Evaluation of calcium hydroxide mixed with propolis by ultrasonic activation as root canal dressing in delayed tooth replantation

Na avulsão dentária ocorre o rompimento do feixe vásculo-nervoso que nutre a polpa e, após o reimplante tardio, existe a necessidade do tratamento endodôntico. A pasta de hidróxido de cálcio (Ca (OH)2) é a medicação intracanal mais empregada em razão de suas excelentes propriedades biológicas, porém várias substâncias têm sido associadas a este na tentativa de melhorar a sua ação antimicrobiana. O objetivo do estudo foi avaliar o efeito do uso de curativo intracanal de hidróxido de cálcio (Ca (OH)2) associado à própole a 10% seguida da agitação ultrassônica em reimplante tardio de dentes de rato. Vinte e quatro ratos tiveram o incisivo superior direito extraído e deixado em bancada por uma hora. Em seguida, foram removidos: papila dentária, polpa dentária e ligamento periodontal. Os dentes foram imersos em solução de fluoreto de sódio fosfato acidulado a 2%. Na sequencia os canais radiculares foram secos e os animais divididos em quatro grupos experimentais: Grupo Ca (OH)2, Grupo Ca (OH)2 seguido da agitação ultrassônica, Grupo Ca(OH)2 e própole, Grupo Ca(OH)2 e própole seguido da agitação ultrassônica. Após a colocação do curativo, foi confeccionado um plug apical de MTA. Os alvéolos foram irrigados com soro fisiológico e os dentes reimplantados. Decorridos 60 dias do reimplante, os animais sofreram eutanásia. Quanto ao infiltrado inflamatório agudo no ligamento periodontal, houve diferença estatisticamente significante entre os grupos Ca(OH)2 e Ca(OH)2 e própole. Com relação ao infiltrado inflamatório crônico no ligamento periodontal, houve diferença significante entre os grupos Ca(OH)2 seguido da agitação ultrassônica e Ca(OH)2 e própole. A reabsorção radicular estava presente em todos os grupos sem diferença estatística. Conclui-se que o uso do curativo intracanal de hidróxido de cálcio associado à própole a 10% seguido da agitação ultrassônica não se mostrou mais efetivo que o Ca(OH)2 no processo de reparo do reimplante tardio de dentes de rato

In tooth avulsion it is the disruption of the neurovascular bundle that nourishes the flesh, and after delayed replantation there is a need for endodontic treatment. Calcium hydroxide (Ca(OH)2) is the most commonly used substance to delay healing, due to its excellent biological properties. However, many substances have been associated with it in an attempt to improve their antimicrobial activity. The aim of this study was to evaluate the effect of intracanal dressing of calcium hydroxide associated with propolis 10% followed by ultrasonic agitation. in delayed replantation of rat teeth. Twenty four rats had the right upper incisor extracted, which was left on the bench-dried for an hour. It was then removed from the dental papilla, and pulp, the periodontal ligament and teeth were immersed in sodium fluoride solution at 2% acidulated phosphate. After this procedure, the root canals were dried with paper cones and the were animals divided into four groups according to the employed intracanal dressing: Group Ca(OH)2, Group Ca(OH)2 with ultrasonic agitation, Group Ca(OH)2 and propolis, Group Ca(OH)2 and propolis with ultrasonic agitation. After placing the bandage, an apical plug of MTA will be made. The root canals were irrigated with saline and the teeth were replanted. Sixty days after replantation, the animals were euthanised. As for the acute inflammatory infiltrate in the periodontal ligament, there was no statistically significant difference between groups Ca(OH)2 and Ca(OH)2 and propolis. Regarding the chronic inflammatory infiltrate in the periodontal ligament, there was no significant difference between group Ca(OH)2 with ultrasonic agitation and the group Ca(OH)2 and propolis. Root resorption was present in all groups with no significant difference between them. It was concluded that the canal dressing of calcium hydroxide associated with propolis 10% followed by ultrasonic agitation was not more effective than Ca(OH)2 in the repair process in...

Influence of root canal disinfectants on growth factor release from dentin.

INTRODUCTION: During dentinogenesis, growth factors become entrapped in the dentin matrix that can later be released by demineralization. Their effect on pulpal stem cell migration, proliferation, and differentiation could be beneficial for regenerative endodontic therapies. However, precondition for success, as for conventional root canal treatment, will be sufficient disinfection of the root canal system. Various irrigation solutions and intracanal dressings are available for clinical use. The aim of this study was 2-fold: to identify a demineralizing solution suitable for growth factor release directly from dentin and to evaluate whether commonly used disinfectants for endodontic treatment will compromise this effect. METHODS: Dentin disks were prepared from extracted human teeth and treated with EDTA or citric acid at different concentrations or pH for different exposure periods. The amount of transforming growth factor-ß1 (TGF-ß1), fibroblast growth factor 2, and vascular endothelial growth factor were quantified via enzyme-linked immunosorbent assay and visualized by gold labeling. Subsequently, different irrigation solutions (5.25% sodium hypochloride, 0.12% chlorhexidine digluconate) and intracanal dressings (corticoid-antibiotic paste, calcium hydroxide: water-based and oil-based, triple antibiotic paste, chlorhexidine gel) were tested, and the release of TGF-ß1 was measured after a subsequent conditioning step with EDTA. RESULTS: Conditioning with 10% EDTA at pH 7 rendered the highest amounts of TGF-ß1 among all test solutions. Fibroblast growth factor 2 and vascular endothelial growth factor were detected after EDTA conditioning at minute concentrations. Irrigation with chlorhexidine before EDTA conditioning increased TGF-ß1 release; sodium hypochloride had the opposite effect. All tested intracanal dressings interfered with TGF-ß1 release except water-based calcium hydroxide. CONCLUSIONS: Growth factors can be released directly from dentin via EDTA conditioning. The use of disinfecting solutions or medicaments can amplify or attenuate this effect.

Antimicrobial peptide-based treatment for endodontic infections--biotechnological innovation in endodontics.

The presence/persistence of microorganisms in the pulp and periapical area corresponds to the maintenance of an exacerbated immune response that leads to the start of periradicular bone resorption and its perpetuation. In endodontic treatment, the available intracanal medications do not have all the desirable properties in the context of endodontic infection and apical periodontitis; they need to include not only strong antimicrobial performance but also an immunomodulatory and reparative activity, without host damage. In addition, there are various levels of resistance to root canal medications. Thus, antimicrobial agents that effectively eliminate resistant species in root canals could potentially improve endodontic treatment. In the emergence of new therapies, an increasing number of studies on antimicrobial peptides (AMPs) have been seen over the past few years. AMPs are defense biomolecules produced in response to infection, and they have a wide spectrum of action against many oral microorganisms. There are some studies that correlate peptides and oral infections, including oral peptides, neuropeptides, and bacterial, fish, bovine and synthetic peptides. So far, there are around 120 published studies correlating endodontic microbiota with AMPs but, according to our knowledge, there are no registered patents in the American patent database. There are a considerable number of AMPs that exhibit excellent antimicrobial activity against endodontic microbiota at a small inhibitory concentration and modulate an exacerbated immune response, down-regulating bone resorption. All these reasons indicate the antimicrobial peptide-based endodontic treatment as an emerging and promising option.

Cellular and molecular tissue response to triple antibiotic intracanal dressing.

INTRODUCTION: The aim of this study was to characterize the response of mouse subcutaneous tissue to triple antibiotic paste (TAP) using conventional light microscopy and real-time PCR (qRT-PCR). METHODS: Polyethylene tubes containing TAP or calcium hydroxide (CH) (ie, the control group) were implanted in mouse subcutaneous tissue. Animals that received empty tubes or no tubes were used as additional controls. After periods of 7, 21, and 63 days postimplantation, the specimens were removed and subjected to histologic processing. The number of inflammatory cells and vessels, vessel areas, vascular density, and relative percentage of collagen were evaluated. Gene expression of proinflammatory (interleukin-1 beta, tumor necrosis factor alpha, and interleukin 17) and anti-inflammatory (transforming growth factor beta) cytokines and angiogenic factors (vascular endothelial growth factor and hypoxia-inducible factor-1 alpha) was quantified by 7 and 21 days postimplantation. Results were analyzed using the Student t test, analysis of variance, and the Tukey test (α = 0.05). RESULTS: TAP induced an exuberant inflammatory and angiogenic response, with higher numbers of inflammatory cells, higher vascular area and density, and lower relative percentage of collagen compared with CH. In general, the expression of genes involved in inflammation and angiogenesis was higher in the TAP group compared with animals that received CH or empty tubes. CONCLUSIONS: The response of mouse subcutaneous tissue to TAP was characterized by exuberant and persistent inflammatory and angiogenic responses with no repair and high gene expression of biomarkers associated with inflammation and angiogenesis.

Effectiveness of two intracanal dressings in adult Portuguese patients: a qPCR and anaerobic culture assessment.

AIM: To quantify bacterial equivalents before and after chemomechanical preparation using 3% sodium hypochlorite (NaOCl) and intracanal dressing with calcium hydroxide paste (Ca(OH)2 ) or 2% Chlorhexidine digluconate gel (CHX) in necrotic pulps associated or not with apical periodontitis and to further compare this quantification with counts of anaerobic microorganisms. METHODOLOGY: Prospective clinical trial in 69 single-rooted adult teeth (strict inclusion criteria); CHX group: 34; Ca(OH)2 group: 35. Bacteria samples were taken at baseline (S1), after chemomechanical preparation (S2) and after 14 days of intracanal dressing (S3). Bacterial equivalents were assessed by broad-range real-time polymerase chain reaction (qPCR), and live viable bacteria measured with conventional anaerobic culture (CFU/mL). Descriptive/inferential analysis was performed with spss vs. 20.0 (α = 0.05) using the Kruskal-Wallis, Mann-Whitney and chi-squared tests and Spearman's correlation coefficients. RESULTS: Both groups showed a significant decrease between S1 and S2 (Mann-Whitney U-test; P < 0.001) both in qPCR and in culture. In the Ca(OH)2 -group, no variation was observed between S2 and S3 by qPCR and culture. In contrast, the CHX group showed a significant increase from S2 to S3 by both techniques. The two groups were only significantly different in S3 (Mann-Whitney U-test; P ≤ 0.001), with a worse performance in the CHX group. Again, these results were congruent by both approaches. Data from both approaches correlate reasonably (rS < 0.5). CONCLUSIONS: Infected root canals contained a high bacterial load, and the chemomechanical root canal preparation reduced bacterial equivalents by 99.1% and anaerobic counts by 98.5%. Intracanal dressings were not efficient at reducing bacterial load, but the 14-day intracanal dressing with Ca(OH)2 performed significantly better than CHX, particularly in cases with apical periodontitis.

Avaliação antimicrobiana dos vapores de para monoclorofenol e tricresol formalina utilizando uma nova metodologia / Antimicrobial evaluation of vapors of paramonochlorophenol and tricresol formalin using a new methodology

O objetivo do presente estudo foi avaliar o efeito antimicrobiano do Paramonoclorofenol Canforado (PMCFC) e do Tricresol Formalina (TF) frente ao Enterococcus faecalis utilizando uma nova metodologia para simular a volatilização dos compostos. Enterococcus faecalis foram inoculados em placas de Petri com BHI, na qual foram fincados escalpes contendo algodão embebido em PMCFC e TF. Bolinhas de algodão sem medicação foram utilizadas como controle negativo. Após 48 horas de cultivo, foi avaliada a formação de halos de inibição de crescimento bacteriano. Pode-se constatar que o grupo com TF produziu halos de inibição em 100% dos escalpes, enquanto o PMCFC e o controle negativo não produziram halo de inibição. Conclui-se que somente o TF apresentou atividade antimicrobiana por volatilização.

The aim of the present study was to evaluate the antimicrobial effects of paramonochlorophenol and tricresol formalin using a new methodology to simulate the volatilization of these substances. Enterococcus faecalis were inoculated em petri dishes with BHI and mm scalps containing cotton balls soaked with the tested substances were stucked in the petri dishes. Cotton balls without medication were used as negative control. After 48 hours the inhibition halo formation was evaluated. The results showed that tricresol formalin group presented inhinition zones in 100% of scalps, while paramochlorophenol and control group produced no inhibition zone. The results suggested that the vapor of formalin tricresol has antibacterial activity; however paramonochlorophenol was unable to exert antibacterial activity from the volatilization of its gases.

Evaluation of calcium ion, hydroxyl ion release and pH levels in various calcium hydroxide based intracanal medicaments: An in vitro study.

AIMS: Evaluation of calcium ion and hydroxyl ion release and pH levels in various calcium hydroxide based intracanal medicaments. OBJECTIVE: The purpose of this study was to evaluate calcium and hydroxyl ion release and pH levels of calcium hydroxide based products, namely, RC Cal, Metapex, calcium hydroxide with distilled water, along with the new gutta-percha points with calcium hydroxide. MATERIALS AND METHODS: The materials were inserted in polyethylene tubes and immersed in deionized water. The pH variation, Ca(++) and OH(-) release were monitored periodically for 1 week. STATISTICAL ANALYSIS USED: Statistical analysis was carried out using one-way analysis of variance and Tukey's post hoc tests with PASW Statistics version 18 software to compare the statistical difference. RESULTS: After 1 week, calcium hydroxide with distilled water and RC Cal raised the pH to 12.7 and 11.8, respectively, while a small change was observed for Metapex, calcium hydroxide gutta-percha points. The calcium released after 1 week was 15.36 mg/dL from RC Cal, followed by 13.04, 1.296, 3.064 mg/dL from calcium hydroxide with sterile water, Metapex and calcium hydroxide gutta-percha points, respectively. CONCLUSIONS: Calcium hydroxide with sterile water and RC Cal pastes liberate significantly more calcium and hydroxyl ions and raise the pH higher than Metapex and calcium hydroxidegutta-percha points.

Calcium hydroxide intracanal dressing removal with different rotary instruments and irrigating solutions: a scanning electron microscopy study

This study evaluated the efficacy of 2 types of rotary instruments employed in association with sodium hypochlorite (NaOCl) or EDTA in removing calcium hydroxide (CH) residues from root canals dentin walls. Forty-two mandibular human incisors were instrumented with the ProTaper System up to F2 instrument, irrigated with 2.5 percent NaOCl followed by 17 percent EDTA and filled with a CH intracanal dressing. After 7 days, the CH dressing was removed using 4 techniques: NiTi rotary instrument size 25, 0.06 taper (K3 Endo) and irrigation with 17 percent EDTA (Group 1), NiTi rotary F1 instrument (ProTaper) and irrigation with 17 percent EDTA (Group 2), NiTi rotary instrument size 25, 0.06 taper and irrigation with 2.5 percent NaOCl (Group 3) and NiTi rotary F1 instrument and irrigation with 2.5 percent NaOCl (Group 4). Two roots without intracanal dressing were used as negative controls. Teeth were evaluated by scanning electron microscopy, in the cervical and apical canal thirds. None of the techniques removed the CH dressing completely. In the apical and cervical thirds, F1 instrument was better than instrument size 25, 0.06 taper in removing CH residues (p<0.05), regardless of the final irrigating solution. No difference was found between the irrigating solutions in the groups of F1 instrument and of instrument size 25, 0.06 taper (p>0.05). The negative controls had no CH residues on the dentin walls. In conclusion, the ProTaper F1 instrument was better than K3 Endo instrument size 25, 0.06 taper in the removal of CH intracanal medication, regardless of irrigating solution used.

O objetivo deste estudo foi avaliar a eficácia de dois tipos de instrumentos rotatórios em associação à irrigação com hipoclorito de sódio (NaOCl) ou EDTA na remoção de resíduos de hidróxido de cálcio (HC) das paredes do canal radicular. Quarenta e dois incisivos inferiores de humanos foram instrumentados com o sistema ProTaper até o instrumento F2, irrigados com NaOCl a 2,5 por cento, seguido de EDTA a 17 por cento e preenchidos com medicação intracanal à base de HC. Após 7 dias, o HC foi removido utilizando 4 técnicas: instrumento 25/0.06 (K3 Endo) e irrigação com EDTA a 17 por cento (Grupo 1), instrumento F1 (ProTaper) e irrigação com EDTA a 17 por cento (Grupo 2), instrumento 25/0.06 e irrigação com NaOCl a 2,5 por cento (Grupo 3) e instrumento F1 e irrigação com NaOCl a 2,5 por cento (Grupo 4). Duas raízes que não receberam medicação intracanal foram utilizadas como controles negativo. Foram avaliados os terços cervical e apical dos canais radiculares por meio de microscopia eletrônica de varredura. Nenhuma das técnicas removeu completamente a medicação à base HC. Nos terços apical e cervical, o instrumento F1 foi melhor do que o instrumento 25/0.06 na remoção dos resíduos de HC (p<0,05), independentemente da solução irrigadora final. Não houve diferença entre as soluções irrigadoras nos grupos do instrumento F1 e do instrumento 25/0.06 (p>0,05). Os controles negativos não apresentaram resíduos de HC nas paredes dentinárias. Concluiu-se que o instrumento F1 do ProTaper foi melhor que o instrumento 25/0.06 do K3 Endo na remoção da medicação intracanal à base de HC, independentemente da solução irrigadora utilizada.

Clorexidina na terapia endodôntica / Chlorhexidine in endodontic therapy

Introdução e objetivo: Este trabalho buscou realizar uma revisão de literatura sobre o emprego da clorexidina no tratamento endodôntico. Revisão da literatura e conclusão: Foram estudadas as propriedades antimicrobianas, de substantividade, biocompatibilidade, capacidadede limpeza e de dissolução tecidual da clorexidina. Em virtude de sua eficácia antimicrobiana, essa droga pode ser empregada como substância irrigadora durante o preparo químico-mecânico, assim como na fase medicamentosa, em casos de polpa morta. Por não possuir capacidade de dissolução tecidual, sua indicação torna-se limitada.Quando comparada às demais concentrações, a clorexidina na concentração de 2% tem apresentado maior efetividade bactericida,com baixa toxicidade. Parece-nos claro que sua efetividade é muito maior como irrigante do que como substância auxiliar na forma de gel. Entretanto recentes estudos sobre a sua genotoxicidade conduzem aum alerta sobre sua indicação segura na terapia endodôntica.

Introduction and objective: The objective of this work was to make a review about the use of chlorhexidine in the endodontic therapy. Literature review and conclusion: Its properties of substantivity, antimicrobial, biocompatibility, cleanliness and tissue dissolution were analyzed. Widely used as an endodontic irrigant during root canal preparation and as an intracanal dressing the inability on tissue dissolution establishes a limitation. In 2% concentration it has show nits better antimicrobial effectiveness and low toxicity, but recent studies about its potential genotoxicity and tissue damage when extruded into the periradicular tissue require new researches to answer important questions.