Volumetric Evaluation of Voids and Gaps of Different Calcium-Silicate Based Materials Used in Furcal Perforations: A Micro-CT Study.

This study aimed at evaluating volumetrically gaps and voids of calcium-silicate based materials of different generations and handling properties (BC­Endosequence BC RRM-Fast Set Condensable Putty, MTA­ProRoot MTA, and BIO­Biodentine) in simulated furcal perforations in an ex vivo setup by microcomputed tomography (Micro-CT) analysis. Thirty-six extracted human mandibular molars with sound furcation areas were selected. Standardized perforations were created in the furcation area of the pulp chamber using #4 diamond burs. The specimens were randomly assigned to three groups (BC, MTA and BIO; n = 12). Samples were then scanned (SkyScan 1172; Bruker-microCT, Kontich, Belgium), and three-dimensional (3D) images reconstructed. The relative volume of gaps (VG%) and voids (VV%) present on each material was calculated. Data were analyzed using one-way analysis of variance (ANOVA) and Tukey's HSD test (p < 0.05). Mean VG% for BC, MTA, and BIO groups were, respectively, 0.513%, 1.128%, 1.460%, with BC presenting statistically (p < 0.05) fewer gaps formation than the other groups. Mean VV% were, respectively, 0.018%, 0.037%, and 0.065%. The was no statistical difference regarding VV%. There were no gap-free and void-free samples. BC group had the lowest VG% among the groups with a significant statistical difference (p < 0.05).

Effectiveness of 1-Visit and 2-Visit Endodontic Retreatment of Teeth with Persistent/Secondary Endodontic Infection: A Randomized Clinical Trial with 18 Months of Follow-up.

INTRODUCTION: This randomized clinical trial aimed to compare the effectiveness of endodontic retreatment of teeth with posttreatment apical periodontitis (PTAP) performed in 1 visit versus 2 visits on the reduction of cultivable bacteria (colony-forming units [CFUs]), lipopolysaccharides (LPSs), lipoteichoic acid (LTA), and the periapical lesion volume (mm3) after 18 months of follow-up. METHODS: Forty patients diagnosed with PTAP were selected and randomly divided into the following 2 groups: 1-visit retreatment and 2-visit retreatment with the placement of calcium hydroxide medication for 14 days. Cone-beam computed tomographic scans were performed at 2 stages: preoperatively and after 18 months of follow-up. Samples were collected before and after root canal procedures. A chromogenic limulus amebocyte lysate assay test was used to quantify endotoxins (EU/mL). LTA levels were measured using the enzyme-linked immunosorbent assay (pg/mL). Culture techniques were used to determine cultivable bacteria by counting the CFU (CFU/mL). The volume of the periapical lesions at the onset of the trial and at the 18-month posttreatment follow-up was obtained by the ITK-SNAP program (Cognitica, Philadelphia, PA). RESULTS: All samples showed baseline values greater than those collected after the retreatment protocol for all investigated parameters. A higher bacterial load and lower LTA level were found in the 2-visit group after the retreatment protocol (P < .05), with no statistical differences between the groups regarding endotoxin levels and periapical lesion volume (mm³) at the 18-month follow-up analyzed by cone-beam computed tomographic imaging (P > .05). CONCLUSIONS: Endodontic retreatment in 1 or 2 visits exhibited equally favorable periapical healing at 18 months, with no statistically significant differences between groups.

Efetividade do tratamento endodôntico em sessão única x múltiplas sessões na periodontite apical pós-tratamento: sinais e sintomas; carga microbiana; níveis de endotoxinas e ácido lipoteicóico e volumetria da destruição óssea periapical por TCFC / Effectiveness of one-visit and two-visits endodontic treatment in posttreatment apical periodontitis: signs and symptoms; microbial load; endotoxin and lipoteichoic acid levels and bone destruction analysis by CBCT in 18-months follow-up

Os objetivos deste estudo foram: a) avaliar o sucesso clínico e por tomografia computadorizada de feixe cônico (TCFC) após 18 meses do retratamento em sessão única (RU) e múltiplas sessões (RM); b) monitorar carga (UFC/mL) e perfil microbiano; níveis de endotoxinas (EU/mL) e de ácido lipoteicóico [LTA (pg/mL)] em dentes com periodontite apical pós-tratamento (PAPT) submetidos a RU e RM; c) comparar a sintomatologia pós-operatória pela escala visual analógica de dor (EVA) em RU e RM; d) comparar os tratamentos quanto à redução de UFC/mL, EU/mL, LTA (pg/mL) e a volumetria da lesão periapical (LP) e) avaliar as correlações e associações entre os dados obtidos no estudo. Seguindo critérios de inclusão e não-inclusão, foram selecionados 40 dentes com PAPT, divididos em dois grupos: RM e RU. Os pacientes foram submetidos à TCFC. Foram realizadas coletas do conteúdo do canal radicular: após remoção do material obturador (S1), após preparo biomecânico (PBM) (S2) e após MIC (S3). Ao final da sessão, foi fornecida a EVA para avaliação da sintomatologia dolorosa apresentada nos períodos de 24hs, 48hs e 7 dias. O conteúdo dos canais radiculares foi avaliado por cultura microbiológica, perfil microbiano por Checkerboard DNA-DNA hybridization, níveis de endotoxinas pelo teste Lisado Amebócito de Limulus e de ácido lipoteicóico pelo ensaio de ELISA. Foi realizada a volumetria da destruição óssea periapical inicial e final por TCFC pelo software ITK snap. Os dados foram analisados estatisticamente. Os níveis de UFC/mL, EU/mL e LTA (pg/mL) diminuíram após o PBM, havendo a manutenção dos mesmos após o uso de MIC (p>0,05). As coletas apresentaram valores iniciais (S1) maiores que os residuais (antes da obturação) para os parâmetros avaliados. Quanto aos valores residuais, foram encontrados maiores valores de UFC/mL em RM e menores valores de LTA no mesmo grupo (p<0,05); porém sem diferença entre os grupos RU e RM quanto aos valores residuais de EU/mL. Os micro-organismos Gram-negativos mais encontrados foram o F. nucleatum, C. rectus, C. gingivalis, P. gingivalis, P. intermedia e L. buccalis, sendo os Gram-positivos: E. faecalis, E. faecium, S. constellatus e S. mitis. Não houve diferença entre os grupos RU e RM quanto à sintomatologia pósoperatória (p>0,05) pela EVA. O volume inicial das LP variou de 10 a 470 mm³, sendo que o final variou de 0 a 48 mm³. Houve redução da média dos volumes de 84,71% em RU e de 90.56% em RM, sendo esta redução significante em ambos os grupos (p< 0,0001), mas sem diferença estatística entre eles (p=0,9117). No período de 18 meses após o retratamento endodôntico não houve diferenças na regressão das lesões e análise dos demais sinais e sintomas entre RU e RM(AU)

This study aimed to: a) evaluate the success rates of one-visit (1-visit) and two-visit (2- visit) endodontic retreatment after 18 months by cone-beam computed tomography (CBCT) and analyze clinical signs and symptoms; b) monitor and compare the microbial load and profile; levels of endotoxins and lipoteichoic acid in teeth with posttreatment apical periodontitis (PTAP); c) compare the postoperative pain between the groups by the visual analog pain scale (VAS); d) correlate the variables with themselves. Forty teeth with PTAP were selected and submitted to CBCT. The sampling procedure was performed: after filling material removal (S1), after biomechanical preparation (S2), and after the intracanal medication placement (S3). VAS was provided for assessment of the postoperative pain at different time-points (24 h, 48 h, and 7 days). Root canal contents were submitted to microbiological assessment by culture technique (CFU/mL) and Checkerboard DNA-DNA hybridization, and the determination of LPS (UE/mL) and LTA (pg/mL) levels by Limulus amebocyte lysate and enzyme-linked immunosorbent assays, respectively. Periapical lesions volumes were obtained by the ITK snap program. Data were statistically analyzed. CFU/mL, UE/mL, and LTA (pg/mL) decreased after biomechanical preparation, with their maintenance after the use of intracanal medication (p>0.05). All root canal samples had their baseline values (S1) higher than those found before the root canal obturation (residual values) for all parameters. Regarding the residual values, higher values of CFU/mL and lower values of LTA were found in 2-visit groups (p<0.05). The most frequently Gram-negative microorganisms found during sampling procedures were F. nucleatum, C. rectus, C. gingivalis, P. gingivalis, P. intermedia and L. buccalis, the Gram-positive ones were E. faecalis, E. faecium, S constellatus and S. mitis. There was no difference between the 1 or 2-visit treatments regarding postoperative symptoms (p>0.05). The initial volume of the periapical lesions ranged from 10 to 470 mm³, and the final ones ranged from 0 to 48 mm³. A significant reduction of the periapical lesion was observed after 18-months in both groups (p<0.0001), but no statistical difference was found between them (p>0.05). No significant differences were observed in the outcome of the two modalities of endodontic retreatment(AU)

Filling ability of three bioceramic root-end filling materials: A micro-computed tomography analysis.

This study aimed at evaluating the volume of gaps and voids, and the total porosity percentage of three calcium-silicate-based materials in mandibular molars apicoectomy by Micro-CT analysis. Thirty-three mesial roots of extracted human mandibular molars were instrumented and obturated. The apical 3mm of each root was resected and prepared. Root-end cavities were filled with EndoSequence BC Putty (BC); ProRoot MTA (MTA) and Biodentine (BIO). Samples were scanned using a Micro-CT scanner and the tridimensional images reconstructed. Percentage of gaps (VG%) and of voids (VV%) were obtained. Porosity percentage (Po%) was also assessed. Data were analysed using Student's t-test (P < 0.05). All materials presented gaps and voids. VG% was 2.006 (BC), 1.882 (MTA) and 1.450 (BIO), and VV% was 0.039 (BC), 0.021 (MTA) and 0.024 (BIO) with no statistical difference. Po% were 56.73 (BC), 51.94 (MTA) and 50.45 (BIO), with BC being statistically (P > 0.05) more porous.

Primary versus post-treatment apical periodontitis: microbial composition, lipopolysaccharides and lipoteichoic acid levels, signs and symptoms.

OBJECTIVES: To compare the microbial load and composition and to determine the lipopolysaccharides (LPS) and lipoteichoic acid (LTA) concentrations found in primary apical periodontitis (PAP) and post-treatment apical periodontitis (PTAP), correlating these findings with clinical/tomographic features. MATERIAL AND METHODS: Sixty patients with PAP (31) and PTAP (29) were submitted to clinical and tomographic assessment. Samples were collected from each root canal using paper points for microbiological assessment (culture technique and Checkerboard DNA-DNA hybridization) and determination of LPS and LTA levels (limulus amebocyte lysate and enzyme-linked immunosorbent assays, respectively). Data were correlated with clinical/tomographic findings and statistically analyzed using the Mann-Whitney and Pearson correlation tests (α = 5%). RESULTS: A higher number of cultivable bacteria and LPS were found in PAP (p < 0.05). The median number of species per root canal found in PAP and PTAP was 9 and 22, respectively (p < 0.05). LPS was positively correlated with a larger periapical lesion volume (p < .05). LTA levels were similar in both infections and had no correlation with signs and symptoms. In PAP, gram-positive bacteria were correlated with spontaneous pain (p < .05) and exudate (p < .05). Tenderness to percussion and pain on palpation were correlated to the presence of both gram-positive and negative bacteria. In PTAP, a positive correlation was observed between both gram-positive and gram-negative bacteria with exudate and periapical lesion volume (p < .05). CONCLUSIONS: PAP had higher contents of microbial load and LPS compared with PTAP. However, PTAP presented a more diverse microbiota compared with PAP. Higher content of LPS was positively correlated with larger periapical bone destruction, whereas signs and symptoms with specific microorganisms. CLINICAL RELEVANCE: It was verified that PAP and PTAP are polymicrobial infections with predominance of gram-negative bacteria and a more diverse bacterial population found in PTAP. A wide interaction of specific microbial species resulted in different clinical features in both infections.

In vitro Evaluation of the Antimicrobial Effect of N-acetylcysteine and Photodynamic Therapy on Root Canals Infected with Enterococcus faecalis.

Introduction: This study aimed to evaluate the in vitro effectiveness of N-acetylcysteine (NAC), photodynamic therapy (PDT) and NAC with supplemental PDT in optimizing the removal of bacteria from infected dentinal tubules of root canals infected with Enterococcus (E.) faecalis biofilm. Methods and Materials: Eighty human teeth were randomly divided into 5 groups (n=16) according to the intracanal medication used: saline solution (control); calcium hydroxide (CH); NAC; PDT; NAC+PDT. Ten samples from each group were prepared for microbiological culture analysis (CFU/mL) and were inoculated with E. faecalis suspension for 21 days for biofilm development; the other six samples from each group were prepared for scanning electron microscopy (SEM) and confocal laser scanning microscopy (CLSM) and submitted to a 5-days contamination protocol including eight centrifugation cycles on every other day for dentinal tubules infection. For antimicrobial activity analysis by microbiological culture (CFU/mL), the root canals were contaminated with E. faecalis biofilm, instrumented and then medicated according to the experimental groups. Three samples were collected from the root canals: after 21-days of contamination, immediately after the instrumentation and 14-days after the medication according to the experimental groups. The morphology of E. faecalis biofilm on the root canal walls and bacterial cells viability were assessed by means of SEM and CLSM, respectively. One-way ANOVA and Repeated Measures ANOVA tests were used to analyze the obtained data statistically. Results: CFU/mL analysis showed that CH, NAC and NAC+PDT promoted greater antibacterial activity with statistically significant difference compared to saline solution and PDT (P<0.0001). However, saline solution and PDT were statistically similar (P>0.07). Illustrative images by SEM confirmed partially the CFU/mL results. CLSM showed that all groups were effective eliminating E. faecalis except for the saline solution group. Conclusions: Based on this in vitro study NAC was bactericidal against E. faecalis biofilms regardless PDT stimulation, presenting similar antimicrobial activity to CH.

Effect of passive ultrasonic activation on microorganisms in primary root canal infection: a randomized clinical trial.

OBJECTIVE: This clinical study sought to evaluate the effectiveness of passive ultrasonic activation (PUA) in eliminating microorganisms in primary endodontic infection (PEI) after instrumentation of root canals using microbiological culture and checkerboard DNA-DNA hybridization. METHODOLOGY: Twenty root canals with PEI and apical periodontitis were selected. The root canals were instrumented and then randomly divided into 2 groups, according to the irrigation method: PUA and conventional needle irrigation (CNI). Microbiological samples were collected before instrumentation (S1), after instrumentation (S2) and after irrigation with 17% EDTA (S3). The samples were subjected to anaerobic culture technique and checkerboard DNA-DNA hybridization analysis. RESULTS: A statistically significant difference was found between CNI (23.56%) and PUA (98.37%) regarding the median percentage values for culturable bacteria reduction (p<0.05). In the initial samples, the most frequently detected species was S. constellatus (50%), and after root canal treatment was E. faecalis (50%). CONCLUSION: Both treatments significantly decreased the number of bacterial species compared with the initial sample. However, no statistical difference in the total microbial load between PUA and CNI groups was detected. The number of cultivable anaerobic bacteria reduced significantly using PUA, and the bacterial composition and number of bacterial species after using either CNI or PUA was similar.

Effect of passive ultrasonic activation on microorganisms in primary root canal infection: a randomized clinical trial

Abstract Objective: This clinical study sought to evaluate the effectiveness of passive ultrasonic activation (PUA) in eliminating microorganisms in primary endodontic infection (PEI) after instrumentation of root canals using microbiological culture and checkerboard DNA-DNA hybridization. Methodology: Twenty root canals with PEI and apical periodontitis were selected. The root canals were instrumented and then randomly divided into 2 groups, according to the irrigation method: PUA and conventional needle irrigation (CNI). Microbiological samples were collected before instrumentation (S1), after instrumentation (S2) and after irrigation with 17% EDTA (S3). The samples were subjected to anaerobic culture technique and checkerboard DNA-DNA hybridization analysis. Results: A statistically significant difference was found between CNI (23.56%) and PUA (98.37%) regarding the median percentage values for culturable bacteria reduction (p<0.05). In the initial samples, the most frequently detected species was S. constellatus (50%), and after root canal treatment was E. faecalis (50%). Conclusion: Both treatments significantly decreased the number of bacterial species compared with the initial sample. However, no statistical difference in the total microbial load between PUA and CNI groups was detected. The number of cultivable anaerobic bacteria reduced significantly using PUA, and the bacterial composition and number of bacterial species after using either CNI or PUA was similar.

Effectiveness in the Removal of Endotoxins and Microbiological Profile in Primary Endodontic Infections Using 3 Different Instrumentation Systems: A Randomized Clinical Study.

INTRODUCTION: This clinical study was conducted to correlate the microbiological profile and levels of endotoxins found in primary endodontic infection with the presence of clinical features and to evaluate the removal of microorganisms and endotoxins using rotary, reciprocating, and hybrid systems for biomechanical preparation. METHODS: Thirty single root canals with primary endodontic infection were evaluated with signs and symptoms and were randomly divided into 3 groups according to the instrumentation system used (n = 10) as follows: rotary Mtwo instruments (VDW, Munich, Germany) with 8 files, the reciprocating Reciproc system (VDW) with a single file, and Genius hybrid instruments with 3 files (1 rotary and 2 reciprocating files) with irrigation using 24 mL 2.5% sodium hypochlorite. Samples were collected before (S1) and after instrumentation (S2) before being submitted to microbiological culture (colony-forming units/mL) and the checkerboard DNA-DNA hybridization test. Endotoxins were quantified using the limulus amebocyte lysate assay. RESULTS: Microbiological culture showed statistical differences in the reduction of colony-forming units/mL with all systems tested (P < .05), but no statistical difference was found among the groups. The most frequently detected species were Capnocytophaga ochracea (53%) and Fusobacterium nucleatum (53%) at S1 and F. nucleatum (50%) and Leptotrichia buccalis (50%) at S2. As for the reduction of endotoxins at S2, Mtwo presented the best results (95.05%) followed by the Genius (91.85%) and Reciproc (64.68%) groups, but no statistical difference was found among the groups. Previous pain, tenderness to percussion, and presence of a sinus tract were associated with specific microorganisms (P < .05). CONCLUSIONS: Signs and symptoms were correlated with microorganisms. Endodontic treatment was effective in reducing bacteria and endotoxins but was not capable of completely removing them from the root canal.

Tratamento endodôntico em sessão única x múltiplas sessões: correlação do sucesso após 1 ano de tratamento com níveis de endotoxinas, carga microbiana e sinais /sintomas / Single visit x multiple visit endodontic treatment: correlation of success after 1 year of treatment with endotoxin levels, microbial load and signs / symptoms

Os objetivos deste estudo foram: a) monitorar carga microbiana (UFC/mL) e níveis de endotoxinas (EU/mL) em dentes com infecção endodôntica primária submetidos a tratamento endodôntico em sessão única (SU) e múltipla sessões (SM); b) relacionar (EU/mL) e (UFC/mL) com sinais e sintomas clínicos, volume do canal radicular e da lesão periapical (mm³), através do uso de tomografia computadorizada de feixe cônico (TCFC); c) comparar o volume da lesão periapical (mm³) antes e após um ano de tratamento nos grupos SU e SM; d) comparar a redução do volume da lesão periapical (mm³) após um ano de tratamento com EU/mL e UFC/mL iniciais e antes da obturação; e) comparar taxa de sucesso encontrado após um ano de tratamento entre SU e SM. Foram selecionados vinte dentes com necrose pulpar e lesão periapical que foram submetidos à TCFC. Foram realizadas coletas do conteúdo do canal radicular: após abertura coronária (S1), após instrumentação com sistema reciprocante Reciproc® e irrigação com hipoclorito de sódio 2,5% (NaOCl) (S2), após uso de EDTA 17% (S3) e após medicação intracanal (MIC) a base de hidróxido de cálcio e solução salina fisiológica (S4). Os conteúdos foram avaliados quanto à atividade antimicrobiana por cultura microbiológica e quanto aos níveis de endotoxinas pelo teste Lisado Amebócito de Limulus. Foi realizada a volumetria dos canais radiculares e da destruição óssea periapical através da TCFC utilizando o software Nemotec®. Por fim, foi realizado controle do tratamento endodôntico, para comparar os tratamentos quanto ao processo de reparo da lesão periapical, relacionando o volume das lesões com os achados clínicos, radiográficos e da tomografia inicial. Os dados foram analisados estatísticamente. Os níveis de UFC/mL e EU/mL diminuíram após o PBM, porém a MIC e o EDTA 17% não interferiram nos resultados; UFC/mL e EU/mL não foram relacionadas a sinais/sintomas e volume da lesão periapical; porém houve correlação entre o volume da lesão periapical e os sinais e sintomas; não houve diferença estatística entre os tratamentos SU e SM na redução das lesões periapicais após um ano e não houve relação entre UFC/mL e EU/mL com a regressão da lesão. Conclue-se, portanto, que o tipo de intervenção (SU x SM) não influenciou no sucesso do tratamento endodôntico.