In vitro evaluation of the action of irrigating solutions associated with intracanal medications on Escherichia coli and its endotoxin in root canals

OBJECTIVE: The purpose of this study was to evaluate the effcacy of auxiliary chemical substances and intracanal medications on Escherichia coli and its endotoxin in root canals. MATERIAL AND METHODS: Teeth were contaminated with a suspension of E. coli for 14 days and divided into 3 groups according to the auxiliary chemical substance used: G1) 2.5% sodium hypochlorite (NaOCl); G2) 2% chlorhexidine gel (CLX); G3) pyrogenfree solution. After, these groups were subdivided according to the intracanal medication (ICM): A) Calcium hydroxide paste (Calen®), B) polymyxin B, and C) Calcium hydroxide paste+2% CLX gel. For the control group (G4), pyrogen-free saline solution was used without application of intracanal medication. Samples of the root canal content were collected immediately after biomechanical preparation (BMP), at 7 days after BMP, after 14 days of intracanal medication activity, and 7 days after removal of intracanal medication. The following aspects were evaluated for all collections: a) antimicrobial activity; b) quantifcation of endotoxin by the Limulus Amebocyte Lysate test (LAL). Results were analyzed by the Kruskal-Wallis and Dunn's tests at 5% signifcance level. RESULTS: The 2.5% NaOCl and CLX were able to eliminate E. coli from root canal lumen and reduced the amount of endotoxin compared to saline. CONCLUSIONS: It was concluded that 2.5% NaOCl and CLX were effective in eliminating E. coli. Only the studied intracanal medications were to reduce the amount of endotoxin present in the root canals, regardless of the irrigant used

Effectiveness of carbamide peroxide and sodium perborate in non-vital discolored teeth

OBJECTIVE: To evaluate the efficacy of 16% carbamide peroxide gel (CP16%), tetrahydrate sodium perborate (SP) and mixture (CP16% + SP), in walking bleaching of non-vital discolored teeth. MATERIALS AND METHODS: Sixty single-rooted human premolars with intact crowns were used and initial color was assessed using Vita shade guide and standardized photos. The teeth were stained using rabbit fresh blood for 18 days and photos of discolored teeth and color evaluation were performed. The teeth were divided into 4 groups (n= 15), according to bleaching agent used: G1) CP16% gel; G2) CP16% gel + SP; G3) SP + distilled water; G4: control. The bleaching agents were replaced twice at 7-day intervals for 21 days. All teeth were evaluated by two endodontists at days 0, 7, 14 and 21 and the color changes were assessed using Vita shade guide and standardized photos. The results were analyzed by Kruskal-Wallis and Dunn's tests (p=0.05). RESULTS: The experimental groups presented statistically similar bleaching results (p>;0.05) at the end of 7, 14 and 21 days. These groups presented significantly higher bleaching efficacy than control group (G4) (

Odontogenic Keratocyst: A Case Report Emphasizing on Root Canal Treatment after Surgical Intervention

This article presents a case of odontogenic Keratocyst (OKC) located in the mandible, involving teeth 36 to 45, with significant loss of alveolar bone and aseptic pulp necrosis, emphasizing on root canal treatment after surgical intervention. Orthopantomogram and computed tomography examinations revealed an extensive, well-defined, and multilocular radiolucent lesion. Histopathological examination after incisional biopsy confirmed OKC, which was removed completely with enucleation and curettage, followed by the endodontic treatments of teeth 36 to 45 using reciprocating nickel-titanium files (Reciproc) in a single session. Afterwards, teeth 33 to 36 underwent apical surgery to create an appropriate bone development. Panoramic radiographic images showed bone formation and no sign of recurrence after one-year follow-up. In conclusion, this surgical approach, combined with the endodontic treatments of the teeth involved in the lesion, was effective for the management of OKC, promoting injury regression and preservation of the natural teeth.Keywords: Dental Pulp Necrosis; Enucleation; Odontogenic Cysts; Odontogenic Keratocyst; Root Canal Therap

Antimicrobial activity of sodium hypochlorite associated with intracanal medication for Candida albicans and Enterococcus faecalis inoculated in root canals

OBJECTIVE: The purpose of this study was to evaluate the action of sodium hypochlorite (NaOCl) associated with an intracanal medication against Candida albicans and Enterococcus faecalis inoculated in root canals. MATERIAL AND METHODS: Thirty-six human single-rooted teeth with single root canals were used. The canals were contaminated with C. albicans and E. faecalis for 21 days and were then instrumented with 1% NaOCl. The roots were divided into 3 groups (n=12) according to the intracanal medication applied: calcium hydroxide paste, 2% chlorhexidine (CHX) gel, and 2% CHX gel associated with calcium hydroxide. The following collections were made from the root canals: a) initial sample (IS): 21 days after contamination (control), b) S1: after instrumentation, c) S2: 14 days after intracanal medication placement; S3: 7 days after intracanal medication removal. The results were analyzed statistically by the Kruskal-Wallis test at 5% significance level. RESULTS AND CONCLUSIONS: Both 1% NaOCl irrigation and the intracanal medications were effective in eliminating E. faecalis and C. albicans inoculated in root canals

Bond strength of cemented fiber posts to teeth with simulated internal root resorption

Teeth with internal root resorption (IRR) have guarded prognosis, considering that IRR defect could influence on the post bond strength. The aim of this study was to evaluate the bond strength and the bond interface between different glass fiber-reinforced posts (FRP) after cementation in teeth with simulated internal root resorption (IRR). Forty-five (45) human premolar roots with simulated IRR were embedded in acrylic resin blocks and cross-sectioned into two segments, enabling them to be re-approximated by screws. Intracanal medication was inserted for 15-days, removed by passive ultrasonic irrigation (PUI) and examined by stereomicroscopy. The push-out bond strength of two fiber reinforced composite posts (Rebilda Post - RP) and Rebilda Post GT ? GT, (VOCO) were evaluated at the cervical and IRR regions (n = 20). And, the bonded interface between resin cement and root dentine was analysed by scanning electron microscopy (SEM). 62.5% of IRR were not completely cleaned by PUI. Bond strength values at the cervical region (9.8 and 14.6 MPa) were higher than the IRR region (6.3 and 4.2 MPa). Micrographies showed bubbles in the cement and spaces in the bonded interface. RP post showed better bond strength at the cervical region while GT had better bond strength at the IRR region

Avaliação in vitro da resistência estrutural em dentes fragilizados utilizando reforços intra-radiculares

lmmature teeth when suffer trauma with consequent necrosis pulpar they stay with its dentinal walls thin and brittle, becoming more susceptible to the second injuries. The purpose of this work is to evaluate through the compression test, the resistance to fracture of teeth bovine brittleness that received reinforcements within the root canal with composite resin or pins of zircônia fiber. lt was used 56 bovine teeth, which had its crowns sectioned in the medium third standardizing the size of the specimens in 30mm of length. The teeth were divided in four experimental groups (14 teeth) and, except for the group 04 (negative control), all the root canal was instrumented to #80 and enlarged firstly with drills Gates-Glidden numbers 3, 4, 5 and 6 to 20mm of depth, after, lhe coronary portion was enlarged with the conical drill number 721 until the cementoenamel junction facial and, with lhe conical drill number 716, the brittleness of the dentinal walls of the root canal at 20mm of depth, leaving 2mm of thickness approximately in each wall. After, the specimens of the group 01 received reinforcement within the root canal with composite resin, that was cured by aid of the Luminex system and, after, they were obturated; in lhe group 02, the specimens were obturated. Just leaving the 10mm apical with material, and they received reinforcement within the root canal with zircônia fiber pins cemented with resinous cement; the group 03 (positive control) it didn't received reinforcement within the root canal and it was obturated by the technique of the active lateral condensation; in the group 04 (negative control), the teeth were not brittleness. After, all the specimens were embedded with acrylic resin chemically activated, in metallic blocks, which were adapted to a cylindrical device, so that the specimens were fractured by load in angle of 45°. This device was adapted to a lnstron machine, ...Dentes com rizogênese incompleta quando sofrem trauma com conseqüente necrose pulpar permanecem com suas paredes dentinárias finas e fragilizadas, tornando-se mais suscetiveis a reincidências de fraturas. A proposta deste trabalho foi avaliar através do teste de compressão a resistência à fratura de dentes bovinos fragilizados que receberam reforços intra-radiculares com resina composta ou pino de fibra de zircônia. Para tanto, utilizou-se 56 dentes bovinos, os quais tiveram suas coroas seccionadas padronizando o tamanho das raízes em 30mm. Os dentes foram divididos em quatro grupos experimentais (14 dentes} e, com exceção do grupo 04 (Controle negativo), todos os canais radiculares foram preparados biomecanicamente até o instrumento de nº 80 e alargados com brocas Gates-Glidden nos 3, 4, 5 e 6 até 20mm de profundidade. A porção coronária foi alargada com broca diamantada tronco cônica nº 721 até a junção cemento-esmalte vestibular e, com broca diamantada tronco cônica nº 716, realizou-se a fragilização das paredes dentinárias do canal radicular a 20mm de profundidade, deixando aproximadamente 2mm de espessura em cada parede. Após, as raízes foram divididas em grupos: grupo 01-receberam reforço intra-radicular com resina composta, fotopolimerizada com o auxílio do sistema Luminex , seguida da obturação do canal; grupo 02-obturação do canal deixando os 10mm apicais com material obturador, e reforço intra-radicular com pino de fibra de zircõnia cimentado com cimento resinoso; o grupo 03-(Controle positivo) não recebeu reforço intra-radicular e foi obturado pela técnica da condensação lateral ativa; no grupo 04-(Controle negativo), os dentes não foram fragilizados. Os espécimes foram embutidos em blocos metálicos, os quais foram adaptados a um dispositivo cilíndrico, de modo que os espécimes foram fixados a 45°. Este dispositivo foi adaptado a um..

Avaliação e correlação da presença de endotoxinas e MMP-3, -8 e -9 em canais radiculares com necrose pulpar submetidos ao tratamento endodôntico - estudo in vivo

It is know that endotoxin and various matrix metalloproteinases (MMPs) are involved in the development of periapical lesions. The purpose of this study was to evaluate and correlate the presence of endotoxins and MMP- 3, MMP-8 and MMP-9 in root canals of teeth with necrotic pulp and periapical lesion before, during and after the biomechanical preparation (PBM) using a combination of different irrigations solutions and intracanal dressing. Thirty-three single-root teeth with a diagnosis of pulp necrosis and periapical lesion radiographically visible were selected. Immediately after the coronal opening was collected the first sample from the root canal content. Then, all canals were prepared (cervical and middle thirds) by oscillatory instruments (EndoEze) and irrigated by 2.5% NaOCl. After, a manual preparation was made for the apical third and the teeth were divided into three groups according to the irrigation protocol: G1) 2.5% NaOCl (4 manual files); G2) 2.5% NaOCl (2 manual files) + [Ca (OH)2 0.14%] (2 manual files) and G3) 2.5% NaOCl (2 manual files) + polymyxin B (2 manual files). After the PBM, the second sample was collected; then the third collect was performed after using EDTA final flush. The fourth sample was collected 14 days after placing the dressing [2% chlorhexidine gel + Ca(OH)2]. Quantification of endotoxins was performed by a kinetic chromogenic lysate from amoebocytes of Limulus (LAL) and quantification of MMPs by ELISA assay. The results were analyzed statistically by Kruskal-Wallis and Dunn's test (5%) and ordinal Spearman correlation. Presence of endotoxin was observed in 100% of cases and G3 showed the greatest reduction of endotoxins from the 1st to the 2nd samples (97%), being statistically similar to G2 (84.2%) and different from G1 (49.4%) (p<0.05). The intracanal dressing promoted a significant reduction of endotoxin, no difference among the groups. For...Sabendo do envolvimento de endotoxinas e diferentes metaloproteinases da matriz (MMPs) no desenvolvimento de alterações periapicais, o objetivo desta pesquisa foi avaliar e correlacionar a presença de endotoxinas e MMP-3, MMP-8 e MMP-9 em canais radiculares de dentes com necrose pulpar e lesão periapical antes, durante e após a realização do preparo biomecânico (PBM) utilizando associação de diferentes agentes irrigantes e medicação intracanal. Foram selecionados 33 dentes unirradiculares com diagnóstico de necrose pulpar e que apresentavam lesão periapical visível radiograficamente. Imediatamente após a abertura coronária foi realizada a 1ª coleta do conteúdo do canal radicular. Em seguida, todos os canais tiveram os terços cervical e médio preparados utilizando 4 instrumentos oscilatórios (EndoEze) com NaOCl 2,5% como agente irrigante. Após, para preparo manual do terço apical, os dentes foram divididos em 3 grupos de acordo com o protocolo de irrigação: G1) NaOCl 2,5% (4 limas manuais); G2) NaOCl 2,5% (2 limas manuais) + água de cal [Ca(OH)20,14%] (2 limas manuais) e G3) NaOCl 2,5% (2 limas manuais) + polimixina B (2 limas manuais). Após PBM foi realizada a 2ª coleta e após o uso do EDTA foi realizada a 3ª coleta. A 4ª coleta foi realizada 14 dias após a colocação da medicação intracanal [pasta de clorexidina gel 2% + Ca(OH)2]. A quantificação de endotoxinas foi realizada através do teste cinético cromogênico do lisado de amebócitos de Limulus (LAL) e a quantificação de MMPs pelo teste imunoenzimático ELISA. Os resultados foram analisados estatisticamente [Kruskal-Wallis e teste de Dunn (5%) e Correlação Ordinal de Sperman]. Foi observada presença de endotoxinas em 100% dos casos e o grupo G3 foi o que apresentou maiores valores de redução de endotoxinas da 1ª para 2ª coleta (97%), sendo estatisticamente semelhante a G2 (84,2%) e..