Clinical Study of Antimicrobial Efficacy of Laser Ablation Therapy with Indocyanine Green in Root Canal Treatment.

INTRODUCTION: Laser ablation (LA) therapy is used as an adjunct to endodontic treatment to improve microbial reduction. However, studies evaluating the impact of LA with indocyanine green (ICG) are scarce. This study aimed to evaluate the antimicrobial efficacy of LA therapy with ICG in root canal treatment. METHODS: Sixty patients with periapical lesions in teeth with a single canal and absence of pain, edema, and previous treatment were selected. Patients were randomly allocated into 3 groups according to the apical sizes used (n = 20); 25/04, 30/04, and 35/04 were the final sizes used. In half the patients of each group, 2.5% sodium hypochlorite was used as an irrigating solution, and in the other half, saline solution was used. After instrumentation, all patients received LA therapy with ICG. Root canal sampling was performed before (S1) and after (S2) root canal instrumentation and immediately after LA therapy with ICG (S3). Colony-forming units were counted, and statistical tests were applied (P < .05). RESULTS: There was a significant reduction in colony-forming units from S1 to S2 in all treatment protocols (P < .05); 2.5% sodium hypochlorite as an irrigating solution showed a greater microbial reduction compared with saline solution (P < .05). LA therapy with ICG further reduced the microbial counts significantly (S2 to S3 and S1 to S3) whether sodium hypochlorite or saline was used (P < .05). CONCLUSIONS: LA therapy with ICG significantly increased microbial reduction in root canals regardless of instrumentation sizes or the irrigation solution used.

Interleukin-6, tumor necrosis factor-α, and CD5 immunolabeling of new experimental endodontic sealer and repair material.

The aim of this study was to evaluate the biocompatibility and immunoinflammatory response of the Sealepox and Sealepox-RP, based on interleukin (IL)-6, tumor necrosis factor (TNF)-α, and CD5 immunolabelling. The ProRoot MTA (PRMTA) was used for comparison. Polyethylene tubes (1.0-mm internal, 1.6-mm external diameter, and 10.0-mm length; ISO 10993) with or without (control) materials were randomly implanted in the dorsum of 35 rats (4 per rat). After 7, 15, 30, 60, and 90 days (n = 7), the tubes were removed for histological and immunohistochemical analysis. The Kruskal-Wallis and Dunn's test for non-parametric data and, ANOVA and Tukey test for parametric data were used (P < 0.05). Hematoxylin and eosin staining revealed that the concentration of inflammatory cells decreased over time with no differences between groups in all periods (P > 0.05). Regarding IL-6 immunostaining, there was no difference at 7 days (P > 0.05); all groups decreased over time, being faster for the PRMTA group and also, with no differences between groups in the last period (P > 0.05). For TNF-α, at 7 days there was no difference between groups (P > 0.05); there was an increase at 15 days for PRMTA and, at 30 and 60 days, for PRMTA and Sealepox compared to the control (P < 0.05). At 90 days, Sealepox RP showed the lowest immunostaining being similar to the control (P > 0.05). Regarding CD5 cells, at 7 days, there was high immunostaining for PRMTA compared to the control (P < 0.05); and significant reduction over time with difference for all groups at 30 and 60 days. (P < 0.05); Sealepox was similar to the control in all periods (P > 0.05). Sealepox RP showed the highest immunostaining at 15 days, being different from the control and PRMTA (P < 0.05); in the other periods it was similar to the control (P > 0.05). It can be concluded that Sealepox and Sealepox-RP were biocompatible and demonstrated similar immunoinflammatory response regarding IL-6, TNF-α, and CD5 compared to PRMTA.

Techniques for in vivo assessment of myopathies in broiler chicken breasts using a biopsy as a support tool.

An experiment was conducted to validate non-invasive evaluation techniques as in vivo evaluation tools for the myopathies wooden breast and white striping that affect broilers, using biopsy as a support tool. It evaluated 30 Cobb 500® broiler chickens in a completely randomized design consisting of two sexes (males and females) and 15 replications per treatment. At 14, 21, 35, 42 and 49 days, the surface temperature of the birds' breasts was recorded using infrared thermography, analysis of fillet depth, and echogenicity by ultrasound imaging. All broiler chickens were sent for biopsy at 21, 35 and 42 days to collect a fragment of the pectoral muscle for descriptive morphological analyses of histological lesions and muscle fibre morphometry. Males had higher echogenicity values at 14, 21 and 42 days. There was no influence of bird sex on the occurrence of the wooden breast and white striping myopathies at 49 days of age in broilers selected and submitted to the biopsy protocol. There was a general trend of decreasing surface temperature for both sexes according to their age. Muscles with less area occupied with fibres had a lower surface temperature. It was concluded that ultrasonography with a 3.5 MHz transducer detects muscle changes after 28 days of age, which is consistent with the myopathic lesions studied. Infrared thermography is a potential method for detecting changes in breast temperature indicating myopathic lesions. A biopsy can be used as an auxiliary tool in the study of myopathies in broiler chicken breasts.RESEARCH HIGHLIGHTS Detection of changes in the breast muscle after 28 days of age with ultrasonography.Changes in the surface temperature range of pectoral muscle with infrared thermography.Use of biopsy as a tool for early diagnostic evaluation in broiler myopathies.

Physicochemical properties, cytotoxicity and penetration into dentinal tubules of sodium hypochlorite with and without surfactants.

OBJECTIVES: The aim of this study was to assess the physicochemical properties, cytotoxicity and penetration into dentinal tubules of ChlorCid™ Surf (3% sodium hypochlorite [NaOCl] with surfactant) in comparison to ChlorCid™ (3% NaOCl without surfactant). MATERIALS AND METHODS: The physicochemical properties evaluated were pH, surface tension, free available chlorine (FAC) and contact angle. Cytotoxicity was evaluated in L929 fibroblasts exposed to the solutions by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide and neutral red assays. Assessment of penetration into dentinal tubules was performed by staining single-rooted permanent human teeth with crystal violet (n = 9), which were irrigated with the solutions and analyzed in cervical, middle and apical segments. Data were analyzed by one-way analysis of variance (ANOVA) and Tukey's post-test, 2-way ANOVA and Bonferroni's post-test or t-test (α = 0.05). RESULTS: ChlorCid™ Surf and ChlorCid™ FAC values were close to those indicated by the manufacturer. ChlorCid™ Surf showed lower surface tension and contact angle on dentin, and higher pH than ChlorCid™ (p < 0.05). The penetration of ChlorCid™ Surf was higher in cervical and middle segments, compared with ChlorCid™ (p < 0.05). There was no difference in irrigant cytotoxicity (p > 0.05). CONCLUSIONS: ChlorCid™ Surf showed lower surface tension, lower contact angle on root canal dentin, higher penetration into dentinal tubules and more alkaline pH, compared with ChlorCid™. However, both solutions showed similar cytotoxicity and FAC content.

Antimicrobial and biofilm anti-adhesion activities of silver nanoparticles and farnesol against endodontic microorganisms for possible application in root canal treatment.

OBJECTIVE: This study aimed to evaluate the antimicrobial and biofilm anti-adhesion activities of poly(vinyl alcohol)-coated silver nanoparticles (AgNPs-PVA) and farnesol against Enterococcus faecalis, Candida albicans or Pseudomonas aeruginosa. DESIGN: Minimum inhibitory concentration (MIC) and minimum microbicidal concentration (MMC) of the solutions, as well as the effect on the biofilm biomass were evaluated. The biofilm anti-adhesion activity was evaluated using bovine root dentine treated with the solutions after 3 min of contact and analyzed by scanning electron microscopy (SEM) and by colony-forming units per milliliter (CFU mL-1) counting. Data were analyzed using ANOVA and Tukey's, the paired Student's t-test or Kruskal-Wallis and Dunn's tests (α = 0.05). RESULTS: The MIC and MMC values (MIC/MMC) of the AgNPs-PVA and farnesol against E. faecalis were 42.5/50 µM and 0.85/1.0%, respectively. For C. albicans, the values were 27.5/37.5 µM and 1.75/2.5%; and for P. aeruginosa, 32.5/32.5 µM and 2.5/2.75%, respectively. Both solutions showed reduced biofilm biomass (p < 0.05). SEM analysis showed that dentine blocks treated with both solutions had lower biofilm formation than the control (saline), except for C. albicans. In the CFU mL-1 counting, biofilm cells were viable in the all groups in comparison with control (p > 0.05). CONCLUSIONS: AgNPs-PVA and farnesol showed antimicrobial and biofilm anti-adhesion activities, as well as potential for use as coadjuvant in endodontic treatment, and may be an option as auxiliary procedure for root canal disinfection or to inhibit biofilm formation.

Apical Extrusion of Debris and Irrigants Using Different Irrigation Needles.

This study evaluated the influence of irrigation tip, root canal curvature and final apical diameter on periapical debris and irrigant extrusion during root canal instrumentation. After being classified as mildly or moderately curved, the mesiobuccal root canals of 90 human molars were instrumented. The teeth were allocated into three groups according to the used needle type: a flat open-end needle (Group 1), a side-vented needle (Group 2) or a double side-vented needle (Group 3). The amount of extruded material after instrumentation was calculated for each group. The differences in irrigant and debris extrusion between the experimental groups were analyzed with the Mann-Whitney U test. Irrigation tips and final instrument diameter differences were analyzed with the Kruskal-Wallis test. Multiple groups were compared using the Mann-Whitney U-test with a Bonferroni correction at α=0.05. The amount of extruded material from the double side-vented needle was significantly less than the open-ended flat needle (p=0.008), but there was no difference compared to the side-vented needle (p=0.929). The results showed no effect of root curvature and final apical diameter on the amount of irrigant and debris extrusion (p>0.05). The double side-vented needles generated the least material extrusion to the periapical tissues. Irrigation needle type had the greatest influence on periapical irrigant and debris extrusion and the double side-vented needles may be safely used during endodontic therapy.

Apical Extrusion of Debris and Irrigants Using Different Irrigation Needles

Abstract This study evaluated the influence of irrigation tip, root canal curvature and final apical diameter on periapical debris and irrigant extrusion during root canal instrumentation. After being classified as mildly or moderately curved, the mesiobuccal root canals of 90 human molars were instrumented. The teeth were allocated into three groups according to the used needle type: a flat open-end needle (Group 1), a side-vented needle (Group 2) or a double side-vented needle (Group 3). The amount of extruded material after instrumentation was calculated for each group. The differences in irrigant and debris extrusion between the experimental groups were analyzed with the Mann-Whitney U test. Irrigation tips and final instrument diameter differences were analyzed with the Kruskal-Wallis test. Multiple groups were compared using the Mann-Whitney U-test with a Bonferroni correction at α=0.05. The amount of extruded material from the double side-vented needle was significantly less than the open-ended flat needle (p=0.008), but there was no difference compared to the side-vented needle (p=0.929). The results showed no effect of root curvature and final apical diameter on the amount of irrigant and debris extrusion (p>0.05). The double side-vented needles generated the least material extrusion to the periapical tissues. Irrigation needle type had the greatest influence on periapical irrigant and debris extrusion and the double side-vented needles may be safely used during endodontic therapy.

Resumo Este estudo avaliou a influência do tipo de agulha de irrigação, curvatura do canal radicular e diâmetro apical final sobre a extrusão de detritos e solução irrigadora durante o preparo físico-químico do canal radicular. O canal mésio- vestibular de 90 molares foi instrumentado, após ser classificado como de curvatura leve ou moderada. Os dentes foram divididos de acordo com o tipo de agulha utilizada em 3 grupos: agulha de extremidade aberta (Grupo 1), agulha de extremidade fechada com abertura lateral (Grupo 2) ou agulha de extremidade fechada com dupla abertura lateral (Grupo 3). A quantidade de material extruído após a instrumentação foi calculada em cada grupo. As diferenças de extrusão de solução irrigadora e detritos entre os grupos experimentais foram analisados com o teste de Mann-Whitney. As diferenças entre o tipo de agulha de irrigação e o diâmetro apical final foram analisados com o teste de Kruskal-Wallis. Grupos múltiplos foram comparados usando o teste U de Mann-Whitney com correção de Bonferroni em α= 0,05. A quantidade de material extruído pela agulha de extremidade fechada com dupla abertura lateral foi significativamente menor do que a agulha de extremidade aberta (p = 0,008), porém não houve diferença em relação a agulha de extremidade fechada com abertura lateral (p = 0,929). Os resultados não indicaram relação entre a curvatura radicular e o diâmetro apical final sobre a quantidade de solução irrigante e detritos de extruídos (p> 0,05). O uso de agulhas com dupla abertura lateral resultaram em uma menor extrusão de material aos tecidos periapicais. O tipo de agulha de irrigação teve a maior influência sobre extrusão periapical de solução irrigadora e detritos. As agulhas de extremidade fechada com dupla abertura lateral podem ser utilizadas com segurança durante a terapia endodôntica.

Antimicrobial Activity and pH of Calcium Hydroxide and Zinc Oxide Nanoparticles Intracanal Medication and Association with Chlorhexidine.

AIM: To evaluate pH and antibacterial activity of pastes with calcium hydroxide [Ca(OH)2] and zinc oxide (ZnO) microparticles (micro) or nanoparticles (nano) and association with 0.4% chlorhexidine against Enterococcus faecalis. MATERIALS AND METHODS: The following pastes were analyzed: Ca(OH)2/ZnO micro, (2) Ca(OH)2/ZnO nano, (3) Ca(OH)2/ ZnO micro + 0.4% chlorhexidine, (4) Ca(OH)2/ZnO nano + 0.4% chlorhexidine. Antibacterial activity against E. faecalis was evaluated by agar diffusion test. The direct contact test on planktonic cells of E. faecalis was performed for 30 and 60 seconds. Root canals from bovine teeth were filled with the pastes and pH was evaluated after 1, 7, 14, 21, 30 and 60 days. The data obtained were submitted to the statistical tests analysis of variance (ANOVA) and Tukey or Kruskal-Wallis and Dunn test, with a 5% significance level. RESULTS: Calcium hydroxide and zinc oxide nano, and the pastes with 0.4% chlorhexidine were more effective in agar diffusion test. In the direct contact test, the pastes with chlorhexidine showed the highest effect after 30 seconds. All pastes eliminated E. faecalis after 60 seconds. All pastes promoted an increase in pH. The highest increase in pH was observed with nanoparticle medications after 1 and 7 days (p < 0.05). After this period, the pastes presented similar pH increase. CONCLUSION: It was concluded that calcium hydroxide and zinc oxide nanoparticles promoted greater initial alkalinization. The antimicrobial activity of the pastes against E. faecalis is favored by the association with chlorhexidine. CLINICAL SIGNIFICANCE: Although nanoparticles of calcium hydroxide and zinc oxide promoted antibacterial effect, the activity against E. faecalis is favored by association with chlorhexidine.

Radiographic evaluation of root canal cleaning, main and laterals, using different methods of final irrigation / Avaliação radiográfica da limpeza de canais radiculares, principal e laterais, utilizando diferentes métodos de irrigação final

Objective: To evaluate the efficacy of passive ultrasonic irrigation (PUI) using intermittent or continuous flushing and conventional manual irrigation (CMI) on the cleaning of main and simulated lateral root canals. Material and Method: The root canals of 24 artificial teeth were prepared and simulated lateral canals were made in the medium and apical thirds of the root. The specimens were divided into three groups: G1- CMI, G2- PUI 1 (intermittent flushing) and G3- PUI 2 (continuous flushing). Root canals were filled with contrast solution and the roots were radiographed pre- and post-irrigation. The digital images were transferred to Image Tool 3.0 software and the areas of root canal completely filled with contrast, and after irrigation with contrast remnant, were measured to obtain percentage data. Statistical analysis between groups was performed by ANOVA and Tukey tests. Result: In the apical third, G2 and G3 (PUI) groups showed higher percentage of cleaning than G1 (CMI) (p<0.05). Conclusion: Passive ultrasonic irrigation using intermittent flushing promoted a higher cleaning of simulated lateral canals than conventional manual irrigation in the apical third. There were no differences between groups in the main root canal and the middle third. .

Objetivo: O objetivo deste estudo foi avaliar a eficácia da irrigação ultrassônica passiva (IUP), utilizando os fluxos intermitente ou contínuo, e da irrigação manual convencional (IMC) na limpeza de canais radiculares, principal e laterais simulados. Material e Método: Os canais radiculares de 24 dentes artificiais foram preparados e os canais laterais foram confeccionados nos terços médio e apical. Os espécimes foram divididos em três grupos: G1- IMC, G2- IUP 1 (fluxo intermitente) e G3- IUP 2 (fluxo contínuo). Os canais radiculares foram preenchidos com uma solução de contraste e as raízes foram radiografadas antes e após a irrigação. As imagens digitais foram importadas para o programa Image Tool 3.0 e as áreas do canal totalmente preenchidas com o contraste, e após a irrigação, com remanescente do contraste, foram mensuradas para obtenção de dados percentuais. A análise estatística entre os grupos foi realizada por meio dos testes ANOVA e Tuckey. Resultado: No terço apical, os grupos G2 e G3 (IUP) mostraram melhor limpeza do que o grupo G1 (IMC) (p<0.05). Não houve diferenças estatisticamente significantes entre os grupos G2 e G3 (p>0.05). Conclusão: Irrigação ultrassônica passiva com fluxo intermitente promoveu melhor limpeza dos canais laterais simulados do que a irrigação manual convencional no terço apical do canal radicular. Não houve diferenças entre os grupos no canal principal e no terço médio. .

Fracture resistance of teeth submitted to several internal bleaching protocols.

AIM: The aim of this study was to evaluate the fracture resistance of teeth submitted to several internal bleaching protocols using 35% hydrogen peroxide (35HP), 37% carbamide peroxide (37CP), 15% hydrogen peroxide with titanium dioxide nanoparticles (15HPTiO2) photoactivated by LED-laser or sodium perborate (SP). MATERIALS AND METHODS: After endodontic treatment, fifty bovine extracted teeth were divided into five groups (n = 10): G1-unbleached; G2-35HP; G3-37CP; G4-15HPTiO2 photoactivated by LED-laser and G5-SP. In the G2 and G4, the bleaching protocol was applied in 4 sessions, with 7 days intervals between each session. In the G3 and G5, the materials were kept in the pulp teeth for 21 days, but replaced every 7 days. After 21 days, the teeth were subjected to compressive load at a cross head speed of 0.5 mm/min, applied at 135° to the long axis of the root using an eletromechanical testing machine, until teeth fracture. The data were submitted to ANOVA and Tukey tests (α = 5%). RESULTS: The 35HP, 37CP, 15HPTiO2 and SP showed similar fracture resistance teeth reduction (p > 0.05). All bleaching treatments reduced the fracture resistance compared to unbleached teeth (p < 0.05). CONCLUSION: All bleaching protocols reduced the fracture resistance of endodontically-treated teeth, but there were no differences between each other. CLINICAL SIGNIFICANCE: There are several internal bleaching protocols using hydrogen peroxide in different concentrations and activation methods. This study evaluated its effects on fracture resistance in endodontically-treated teeth.

A method for retrieving endodontic or atypical nonendodontic separated instruments from the root canal: a report of two cases.

AIM: This clinical report presents a new method for retrieving separated instruments from the root canal with minimally invasive procedures. BACKGROUND: The presence of separated instrument in root canal may interfere in the endodontic treatment prognosis. There are several recommended methods to retrieve separated instruments, but some are difficult in clinically practice. CASE REPORT: This study describes two cases of separated instrument removal from the root canal using a stainless-steel prepared needle associated with a K-file. Case 1 presented a fractured gutta-percha condenser within the mandibular second premolar, it was separated during incorrect intracanal medication calcium hydroxide placement. Case 2 had a fractured sewing needle within the upper central incisor that the patient used to remove food debris from the root canal. After cervical preparation, the fractured instruments were fitted inside a prepared needle and then an endodontic instrument (#25 K-file) was adapted with clockwise turning motion between the needle inner wall and the fragment. CONCLUSION: The endodontic or atypical nonendodontic separated instrument may be easily pull on of the root canal using a single and low cost device. CLINICAL SIGNIFICANCE: The methods for retrieving separated instruments from root canal are difficult and destructive procedures. The present case describes a simple method to solve this problem.

The efficacy of the self-adjusting file and ProTaper for removal of calcium hydroxide from root canals.

OBJECTIVE: The goal of this study was to evaluate the efficacy of the Self-Adjusting File (SAF) and ProTaper for removing calcium hydroxide [Ca(OH)2] from root canals. MATERIAL AND METHODS: Thirty-six human mandibular incisors were instrumented with the ProTaper system up to instrument F2 and filled with a Ca(OH)2-based dressing. After 7 days, specimens were distributed in two groups (n=15) according to the method of Ca(OH)2 removal. Group I (SAF) was irrigated with 5 mL of NaOCl and SAF was used for 30 seconds under constant irrigation with 5 mL of NaOCl using the Vatea irrigation device, followed by irrigation with 3 mL of EDTA and 5 mL of NaOCl. Group II (ProTaper) was irrigated with 5 mL of NaOCl, the F2 instrument was used for 30 seconds, followed by irrigation with 5 mL of NaOCl, 3 mL of EDTA, and 5 mL of NaOCl. In 3 teeth Ca(OH)2 was not removed (positive control) and in 3 teeth canals were not filled with Ca(OH)2 (negative control). Teeth were sectioned and prepared for the scanning electron microscopy. The amounts of residual Ca(OH)2 were evaluated in the middle and apical thirds using a 5-score system. RESULTS: None of the techniques completely removed the Ca(OH)2 dressing. No difference was observed between SAF and ProTaper in removing Ca(OH)2 in the middle (P=0.11) and the apical (P=0.23) thirds. CONCLUSION: The SAF system showed similar efficacy to rotary instrument for removal of Ca(OH)2 from mandibular incisor root canals.

The efficacy of the self-adjusting file and ProTaper for removal of calcium hydroxide from root canals

OBJECTIVE: The goal of this study was to evaluate the efficacy of the Self-Adjusting File (SAF) and ProTaper for removing calcium hydroxide [Ca(OH)2] from root canals. MATERIAL AND METHODS: Thirty-six human mandibular incisors were instrumented with the ProTaper system up to instrument F2 and filled with a Ca(OH)2-based dressing. After 7 days, specimens were distributed in two groups (n=15) according to the method of Ca(OH)2 removal. Group I (SAF) was irrigated with 5 mL of NaOCl and SAF was used for 30 seconds under constant irrigation with 5 mL of NaOCl using the Vatea irrigation device, followed by irrigation with 3 mL of EDTA and 5 mL of NaOCl. Group II (ProTaper) was irrigated with 5 mL of NaOCl, the F2 instrument was used for 30 seconds, followed by irrigation with 5 mL of NaOCl, 3 mL of EDTA, and 5 mL of NaOCl. In 3 teeth Ca(OH)2 was not removed (positive control) and in 3 teeth canals were not filled with Ca(OH)2 (negative control). Teeth were sectioned and prepared for the scanning electron microscopy. The amounts of residual Ca(OH)2 were evaluated in the middle and apical thirds using a 5-score system. RESULTS: None of the techniques completely removed the Ca(OH)2 dressing. No difference was observed between SAF and ProTaper in removing Ca(OH)2 in the middle (P=0.11) and the apical (P=0.23) thirds. CONCLUSION: The SAF system showed similar efficacy to rotary instrument for removal of Ca(OH)2 from mandibular incisor root canals. .

Efficacy of four irrigation needles in cleaning the apical third of root canals.

This study aimed to evaluate the influence of irrigation needle gauge and design, and the final root canal diameter on the apical cleaning efficacy. Twelve human mandibular incisors were used. At different stages of root canal widening (sizes 20, 30 and 40 K-files), root canals were filled with radiopaque contrast medium. Four different needles were evaluated: 23G with side opening, 22G with apical opening, 30G with side opening and 30G with apical opening. Irrigation was carried out with 2mL distilled water. The same tooth was radiographed with a digital system several times to assess the four types of needle in those three stages of canal widening. Pre-irrigation (canals filled with contrast) and post-irrigation (canals with remaining contrast) images were submitted to digital subtraction using the Adobe Photoshop CS4 program. Pre-irrigation (filled with contrast) and subtracted (cleaned by irrigation) areas were outlined by a trained and blinded operator using the Image Tool 3.0 software. Their ratio was calculated to express the percentage of apical cleaning in each stage of canal widening (sizes 20, 30 and 40 K-files) with each of the four needles. Data obtained were subjected to one-way ANOVA and Tukey's tests. The 30G needles with side and apical opening promoted better apical cleaning at all stages of root canal widening (p<0.05). In conclusion, smaller diameter needles were more efficacious in cleaning the apical third of the root canals, regardless of their design.

Apexification with white MTA in an immature permanent tooth with dens invaginatus

Dens invaginatus, also known as “dens in dente”, is a developmental dental anomaly resulting in an invagination of the enamel organ into the dental papilla. These cases present technical difficulties to the root canal treatment. Apexification using an apical plug of mineral trioxide aggregate (MTA) has been indicated as an alternative to long-term intracanal use of calcium hydroxide in immature permanent teeth. It is considered as a simple and rapid technique. This paper reports a case of Oehlers’ Type 1 dens invaginatus in an immature permanent maxillary right lateral incisor, which presented pulp necrosis secondary to dental trauma and was treated by apexification with white MTA apical plugging followed by conventional root canal therapy. The operative procedures are described and the technique is discussed. The physical and biological properties of MTA, associated with appropriate instrumentation and obturation techniques, make this material an excellent option in the endodontic therapy of immature permanent teeth with dens invaginatus.

Evaluation of the physicochemical properties and push-out bond strength of MTA-based root canal cement.

AIM: This study investigated the flowability, setting time, pH, calcium release and bond strength of a MTA-based cement (MTA Fillapex(®)) compared to AH Plus and Sealapex. MATERIALS AND METHODS: For the flowability test, the ISO 6876:2001 specification was utilized and for the setting time test, the ASTM C266-03 specification was utilized. For the pH and calcium release measurements, 10 samples were prepared for each group and analyzed for several different periods. For the push-out test, dentin disks were distributed into three groups, according to the cement utilized and into three subgroups, according to the root third (n = 10). After obturation, the specimens underwent push-out testing. The data were compared statistically using a significance level of 5%. RESULTS: The flowability of all materials was found to be similar (p > 0.05). The setting times were different among the groups tested (MTA Fillapex < Sealapex < AH Plus) (p < 0.05). At days 7 and 28, the MTA Fillapex presented the higher pH values (p < 0.05). At 24 hours and at 14 days, the calcium release of the MTA Fillapex was similar to that of Sealapex (p > 0.05). AH Plus presented the lowest pH and calcium release values (p < 0.05). In all root thirds, the adhesion to the dentin of the MTA Fillapex and Sealapex were significantly lower than that of AH Plus (p < 0.05). CONCLUSION: MTA Fillapex and Sealapex presented several similar properties and both were found to be different than AH Plus. CLINICAL SIGNIFICANCE: This study evaluated the physicochemical and mechanical properties of new MTA-based root canal cement, in order to use this scaler in root canal fillings. MTA Fillapex showed satisfactory properties for clinical use.

Efficacy of four irrigation needles in cleaning the apical third of root canals

This study aimed to evaluate the influence of irrigation needle gauge and design, and the final root canal diameter on the apical cleaning efficacy. Twelve human mandibular incisors were used. At different stages of root canal widening (sizes 20, 30 and 40 K-files), root canals were filled with radiopaque contrast medium. Four different needles were evaluated: 23G with side opening, 22G with apical opening, 30G with side opening and 30G with apical opening. Irrigation was carried out with 2 mL distilled water. The same tooth was radiographed with a digital system several times to assess the four types of needle in those three stages of canal widening. Pre-irrigation (canals filled with contrast) and post-irrigation (canals with remaining contrast) images were submitted to digital subtraction using the Adobe Photoshop CS4 program. Pre-irrigation (filled with contrast) and subtracted (cleaned by irrigation) areas were outlined by a trained and blinded operator using the Image Tool 3.0 software. Their ratio was calculated to express the percentage of apical cleaning in each stage of canal widening (sizes 20, 30 and 40 K-files) with each of the four needles. Data obtained were subjected to one-way ANOVA and Tukey's tests. The 30G needles with side and apical opening promoted better apical cleaning at all stages of root canal widening (p<0.05). In conclusion, smaller diameter needles were more efficacious in cleaning the apical third of the root canals, regardless of their design.

Este estudo teve como objetivo avaliar a influência do diâmetro e design da agulha de irrigação e do diâmetro do canal radicular na eficácia de limpeza apical. Doze incisivos mandibulares humanos foram utilizados. Em diferentes fases de alargamento do canal radicular (limas tipo K #20, 30 e 40), os canais foram preenchidos com meio de contraste radiopaco. Quatro agulhas diferentes foram avaliadas: 23G com abertura lateral, 22G com abertura apical, 30G com abertura lateral e 30G com abertura apical. A irrigação foi realizada com 2 mL de água destilada. O mesmo dente foi radiografado por um sistema digital, repetidas vezes, para avaliar os quatro diferentes tipos de agulha nas três fases de alargamento do canal. As imagens pré-irrigação (preenchidas por contraste) e pós-irrigação (com contraste restante) foram submetidas à subtração digital por meio do programa Adobe Photoshop CS4. As áreas pré-irrigação (preenchidas por contraste) e subtraídas (limpas pelo irrigante) foram demarcadas por um operador treinado e cego em relação aos grupos experimentais, usando o programa Image Tool 3.0. A proporção dessas duas medidas foi calculada para expressar a porcentagem de limpeza apical em cada estágio de dilatação (20, 30 e 40) com cada agulha. Os dados obtidos foram submetidos aos testes ANOVA a um critério e Tukey com nível de significância de 5%. As agulhas 30G com abertura lateral e apical promoveram melhor limpeza apical em todas as fases de ampliação do canal radicular (p<0,05). Em conclusão, as agulhas de menor diâmetro foram mais eficazes na limpeza do terço apical dos canais radiculares, independentemente do seu design.

Anterior restorations in bleached teeth: difficulty establishing the color after bleaching.

It is becoming more common for patients to look for cosmetic procedures in dental offices. The search for lost or desired esthetics by patients is increasingly frequent and the professional must be able to meet this demand. To do this, dentists not only need to return the tooth back to its normal functioning state but also promote esthetic excellence. In this context, the association of cosmetic procedures, such as teeth whitening and restorative procedures, such as direct adhesive restorations is very common. The composite resins employed nowadays allow the reproduction of various optical properties of natural teeth. With these composite resins, it is possible to reproduce features such as translucency, opacity and specific features of the dental element, to bring back the esthetic harmony of the smile. This article reports a clinical case demonstrating the placement, in a stratified manner, of composite resins in bleached teeth, as well as the reproduction of optical and natural aspects of the teeth. In order to achieve esthetic and functional success of the restored procedure, it is important to be familiar with the new techniques and new materials in the market and above all, we must know when and where to use them.

Influence of the rotary and/or oscillatory reciprocating systems in the morphological changes of narrow and curved molar root canals anatomy / Influência dos sistemas rotatórios e/ou oscilatórios recíprocos nas alterações morfológicas anatômicas de canais radiculares atresiados e curvos

Objetivo: Esse estudo avaliou quatro sistemas endodônticos mecanizados, ProTaper Universal, K3 Endo, Twisted file, (rotatórios) e Endo - Eze TiLOS(oscilatório) para verificar e medir as alterações na anatomia original do canal radicular e desvios nos terços cervical,médio e apical. Material e Método: Foram utilizadas 60 raízes mésio-vestibulares de molares inferiores extraídos de humanos para coleta de medições de ângulos e classificação de Schneider. Os espécimes foram incluídos em resina de Éster vinil e montadas em muflas de Teflon, seccionadas transversalmente nos terços cervical,médio e apical para posterior fotografia usando-se câmera digital Cyber Shot DSC-TX10,acoplada à um microscópio 3101XY DFVasconcelos com 40× de aumento para se mensurar a àrea da secção anatômica transversal do canal radicular utilizando o programa AutoCAD 2008, comparando as àreas pré e pós instrumentação. Todos os espécimes ajustados na mufla foram radiografados de maneira padronizada para permitir a avaliação do ângulo de Schneider pré e pós-instrumentação.Uma vez coletados os dados,os mesmos foram comparados estatisticamente usando-se o programa BioEstat 5.0. Resultado: A análise dos resultados mostrou que no terço cervical os sistemas rotatórios foram mais eficazes que o sistema oscilatório Endo-Eze TiLOS,com diferenças estatisticamente significantes (p ≤ 0,05). As alterações anatômicas relativas ao desvio nos terços apical e médio foram similares, mas apicalmente o sistema ProTaper promoveu mais desvios quando se avaliou o ângulo de Schneider pré e pós instrumentação (p ≤ 0,05). Conclusão: Utilizando-se a alteração do ângulo de Schneider e a diferença entre área dentinária inicial (antes do preparo) e final (pós-preparo), concluiu-se que todos os sistemas causaram desvio na anatomia original do canal radicular.

Objective: This study evaluated four mechanized Endodontic systems, ProTaper Universal, K3 Endo, Twisted file (rotary) and the oscillatory reciprocating system Endo - Eze TiLOS, in order to verify and measure alterations in original anatomy with deviations at cervical, medium and apical root canal thirds. Material and Method: It was used MB root canals of 60 extract human lower molars, to produce a line of severe angles, according to the classification of Schneider. Samples were included in Ester vinyl resin, mounted in the Teflon Furnace, transversally sectioned at the cervical, middle and apical thirds, which were subsequently photographed using a digital camera Cyber Shot DSC-TX10,attached to an operating microscope 3101XY DFVasconcelos with 40× magnification in order to measure the anatomical transversal area of the root canal, using the software AutoCAD 2008, comparing pre and post-instrumentation. All samples assembled in the Furnace also were submitted to x-ray in a standardized way to enable the comparison of the angle of Schneider pre-and post-instrumentation. Once collected the data, they were compared statistically using the program BioEstat 5.0. Result: The analysis of the results showed that in the cervical third, rotary systems were more effective than Endo-Eze TiLOS System with statistically significant differences (p ≤ 0,05). Apical and middle third changes in anatomy were similar, but apically, the ProTaper system caused more deviations when comparing the angle of Schneider,and areas before and after instrumentation(p ≤ 0,05). Conclusion: It was concluded that all the systems caused alteration in the original anatomy of the root canal when parameters as angle of Schneider and areas before and after preparation were used.

Aspectos atuais do tratamento da infeccão endodôntica / Current aspects of root canal system infection's therapy

A Endodontia é uma ciência que engloba a etiologia, diagnóstico, prevenção e tratamento da periodontite apical e suas repercussões no organismo. Recu rsos tecnológ icos no diagnóstico, exploração e novas estratégias associadas principalmente à limpeza e desinfecção do sistema de canais radiculares, modelagem e obturação do espaço endodôntico, de acordo com bases biológicas,permitirão a obtenção de melhores padrões de sucesso pós-tratamento.

Endodontics is a science that embodies etiology, diagnosis, prevention, and treatment of apical periodontitis and its repercussion in the organismo Technological resources in diagnosis and root canal negotiation, and new strategies , associated to mainly cleaning and eliminating the infection of the root canal system, shaping, and filling the endodontic space, according to biological bases, will allow us to reach higher standards of post-treatment success.