Effect of ELVAX polymer subgingival implants with echistatin on extracted and reimplanted rats' teeth.

To investigate the effect of ELVAX polymer subgingival implants incorporated with echistatin peptide on incisor reimplanted tooth in rats. Forty-two male Wistars rats were divided into two groups: echistatin-treated rats (E) and control rats (C). The animals had their right maxillary incisors extracted and treated according to the International Association of Dental Traumatology replantation protocol. The extra-alveolar dry period was 30 and 60 min, and the post-surgical experimental periods were 15, 60, and 90 days. The samples were stained with H&E and analyzed for the presence of an inflammatory response, incidence of resorptions, and dental ankylosis. Results were statistically analyzed (p < 0.05). The presence of inflammatory resorption was significantly higher in group C at 30 and 60 min extra-alveolar time, in the 15-day postoperative period as compared with the E group (p < 0.05). Dental ankylosis was significantly more prevalent in group E in 30 min extra-alveolar time and 15 days postoperative period (p < 0.05). However, in 60 min extra-alveolar time and 60 days postoperative period, dental ankylosis was more prevalent in C group (p < 0.05). The use of ELVAX subgingival implants with echistatin demonstrated therapeutic potential in preventing the experimental resorption process after replantation of maxillary incisors in rats.

Analysis of the physicochemical properties, cytotoxicity and volumetric changes of AH Plus, MTA Fillapex and TotalFill BC Sealer.

BACKGROUND: To evaluate the physicochemical properties and cytotoxicity of AH Plus, MTA Fillapex and TotalFill BC Sealer. Volumetric changes were also evaluating using micro-computed tomography (micro-CT). MATERIAL AND METHODS: Radiopacity and flow were evaluated in accordance with the ISO 6876, while setting time was evaluated in accordance with the ASTM- C266-08 specifications. The release of Ca2+ ions and pH were measured with spectrophotometer and pH meter, respectively, after different time intervals (1h, 3h, 24h, 72h, 168h, and 360h). Cytotoxicity was evaluated by MTT reduction assay to check 3T3 cells viability at 24, 48 and 72 hours. Volumetric change was evaluated by micro-CT, by using 30 acrylic teeth, filled with gutta-percha cones and the tested root canal sealer. The samples were evaluated after 168h, 360h and 720h of immersion in distilled water. Data were statistically analyzed by one-way ANOVA and Tukey test or by Kruskal-Wallis and Dunn tests (P<0.05). RESULTS: MTA Fillapex and TotalFill BC Sealer showed lower radiopacity than AH Plus (P<0.05). The MTA Fillapex showed the highest flow, while AH Plus showed the lowest flow (P<0.05). The initial and final setting time of AH Plus were lower than MTA Fillapex and TotalFill BC Sealer (P<0.05). In general, TotalFill BC Sealer presented higher Ca2+ ion release and pH than the other tested sealers. TotalFill BC Sealer also showed overall lower cytotoxicity when compared to the other sealers. Volumetric change of AH Plus and TotalFill BC Sealer was lower than MTA Fillapex (P<0.05). CONCLUSIONS: AH Plus, MTA Fillapex and TotalFill BC Sealer showed slight differences in the physicochemical properties and cytotoxicity, but all suitable for an endodontic sealer. However, AH Plus and TotalFill BC Sealer showed low volumetric changes when compared to MTA Fillapex. Key words:Calcium silicate, cytotoxicity, physicochemical properties, micro computed tomography.

Tratamento não cirúrgico para remoção de instrumento fraturado e guta-percha extravasada, com o uso do Masserann EndoKit / Non-surgical treatment for removing fractured instrument and extravasated gutta-percha, by using the Masserann EndoKit

Objetivo: o objetivo deste artigo é relatar um caso clínico em que um instrumento fraturado e a guta-percha extravasada foram removidos via canal. Relato de caso: paciente do sexo masculino, com 38 anos de idade, foi encaminhado para avaliação do incisivo lateral superior direito (dente #12). O paciente apresentava dor à palpação na região apical e ausência de sintomatologia espontânea. O exame radiográfico revelou a presença de cone de guta-percha extravasado, uma espiral de Lentulo fraturada, além de lesão periapical no dente #12. O retratamento endodôntico foi o procedimento de escolha, na tentativa de remover os dois materiais. A espiral de Lentulo foi removida com Masserann Endokit; e o cone de guta-percha, utilizando limas Hedstroen. Após realizar a instrumentação e o preenchimento do conduto com pasta de hidróxido de cálcio com iodofórmio, constatou- se a presença de reabsorção no terço apical. Depois de dois meses, observou-se redução da lesão; utilizou-se, então, MTA na região da reabsorção, e o conduto foi obturado com cone de guta-percha e cimento endodôntico Sealer 26. Conclusão: controles clínicos e radiográficos foram realizados após dois, quatro e oito anos, demonstrando reparo na região apical e ausência de sintomatologia (AU).

The objective of this article was to report a clinical case of finding a fractured instrument and over-extended guttapercha of a tooth, which were removed via the canal. The patient, a 38-year-old man, was referred for treatment of the right maxillary lateral incisor (tooth 7). The patient presented pain on palpation at the apical level and absence of spontaneous symptomatology. Radiographic examination revealed the presence of a over-extended gutta-percha cone, a fractured Lentulo spiral and periapical lesion in tooth 7. Endodontic retreatment was the chosen procedure in an attempt to remove both materials. The Lentulo spiral was removed by means of the Masserann Endokit, and the gutta-percha cone by using Hedstroen files. While performing instrumentation, and filling the canal with calcium hydroxide with iodoform, the presence of resorption in the apical third was verified. After 2 months, reduction of the lesion was observed, thus MTA was placed in the area of resorption and the remainder of the canal was filled with a gutta-percha cone and Sealer 26 cement. Clinical and radiographic controls performed after 2, 5 and 7 years showed repair of the area and absence of symptomatology (AU).

CAMPANELLIProgrammed Death 1 (PD-1) and PD-1 Ligand (PD-L1) Expression in Chronic Apical Periodontitis.

OBJECTIVE: This study aimed to examine programmed death protein 1 (PD-1) and programmed death lig-and 1 (PD-L1) expression on leukocytes from chronic apical periodontitis, and to determine the levels of cytokines in the apical periodontitis lesions. METHODS: Leukocytes from healthy gingival tissue (n=16) and chronic apical periodontitis (n=10) were eval-uated using flow cytometry. The PD-1 and PDL-1 expressions were evaluated using flow cytometry. The cy-tokine levels were evaluated by enzyme-linked immunosorbent assay. Data were analyzed using one-way ANOVA. The statistical significance level was set at P<0.05. RESULTS: Results showed that the apical periodontitis lesions are more infiltrated by PD-1+ and PDL1+ lym-phocytes than the control samples. In addition, the PDL-1 expression was detected on macrophages in the apical periodontitis lesions, and was significantly higher compared to leukocytes from healthy gingival tis-sue. The IFN-γ, TGF-ß, IL-10, and TNF-α levels were significantly higher in the apical periodontitis lesions com-pared to control samples. CONCLUSION: The PD-1, PD-L1, and CTLA-4 molecules are evident in apical periodontitis, and can be an impor-tant immune checkpoint in chronic periapical periodontitis.

Comparison of two methods of irrigant agitation in the removal of residual filling material in retreatment.

The aim of this study was to compare the efficacy of passive ultrasonic irrigation and EasyClean for removing residual filling material in retreatment. Twenty-two maxillary lateral incisors with apical curvature were instrumented with ProTaper files and filled with Endofill using the lateral compactation technique. Removal of filling material was performed with Reciproc, Mtwo and ProDesign Logic 50/.01 files. The teeth were inserted in a silicone mould, which was placed in a metal muffle, and split to visualize the residual filling material. The samples were divided into two groups (n = 11) according to the irrigation protocol: Passive ultrasonic irrigation (PUI group) with 3 activations of 20 seconds and EasyClean (Easy Equipamentos Odontológicos, Belo Horizonte, Brazil) (EC group) used in continuous rotation with 3 activations of 20 seconds, both using NaOCl and EDTA. Environmental scanning electron microscopic images of the apical, middle, and cervical thirds were taken before and after the irrigant activation. The Kappa test was used to determine interexaminer agreement. Statistical analysis was performed using Kruskal-Wallis, Mann-Whitney, and Wilcoxon tests (p < 0.05). PUI and EC improved the removal of remnant filling material in all root canal thirds (p < 0.05). PUI and EC presented similar performance in the final step of retreatment (p > 0.05). No significant difference was observed in the removal of filling material in the apical, middle, and cervical thirds in both groups (p > 0.05). EasyClean in continuous rotary motion is useful in retreatment and was shown to be as effective as ultrasonic activation in the removal of remnant filling material.

Prevalence and morphometric analysis of three-rooted mandibular first molars in a Brazilian subpopulation.

OBJECTIVES:: To determine the prevalence of three-rooted mandibular molars in a Brazilian population using cone beam computed tomography (CBCT) and to analyze the anatomy of mandibular first molars with three roots through micro-CT. MATERIAL AND METHODS:: CBCT images of 116 patients were reviewed to determine the prevalence of three-rooted first mandibular molars in a Brazilian subpopulation. Furthermore, with the use of micro-CT, 55 extracted three-rooted mandibular first molars were scanned and reconstructed to assess root length, distance between canal orifices, apical diameter, Vertucci's classification, presence of apical delta, number of foramina and furcations, lateral and accessory canals. The distance between the orifice on the pulp chamber floor and the beginning of the curvature and the angle of canal curvature were analyzed in the distolingual root. Data were compared using the Kruskal-Wallis test (α=0.05). RESULTS:: The prevalence of three-rooted mandibular first molars was of 2.58%. Mesial roots showed complex distribution of the root canal system in comparison to the distal roots. The median of major diameters of mesiobuccal, mesiolingual and single mesial canals were: 0.34, 0.41 and 0.60 mm, respectively. The higher values of major diameters were found in the distobuccal canals (0.56 mm) and the lower diameters in the distolingual canals (0.29 mm). The lowest orifice distance was found between the mesial canals (MB-ML) and the highest distance between the distal root canals (DB-DL). Almost all distal roots had one root canal and one apical foramen with few accessory canals. CONCLUSIONS:: Distolingual root generally has short length, severe curvature and a single root canal with low apical diameter.

Prevalence and morphometric analysis of three-rooted mandibular first molars in a Brazilian subpopulation

ABSTRACT The knowledge of the internal anatomy of three-rooted mandibular molars may help clinicians to diagnose and plan the root canal treatment in order to provide adequate therapy when this variation is present. Objectives: To determine the prevalence of three-rooted mandibular molars in a Brazilian population using cone beam computed tomography (CBCT) and to analyze the anatomy of mandibular first molars with three roots through micro-CT. Material and Methods: CBCT images of 116 patients were reviewed to determine the prevalence of three-rooted first mandibular molars in a Brazilian subpopulation. Furthermore, with the use of micro-CT, 55 extracted three-rooted mandibular first molars were scanned and reconstructed to assess root length, distance between canal orifices, apical diameter, Vertucci's classification, presence of apical delta, number of foramina and furcations, lateral and accessory canals. The distance between the orifice on the pulp chamber floor and the beginning of the curvature and the angle of canal curvature were analyzed in the distolingual root. Data were compared using the Kruskal-Wallis test (α=0.05). Results: The prevalence of three-rooted mandibular first molars was of 2.58%. Mesial roots showed complex distribution of the root canal system in comparison to the distal roots. The median of major diameters of mesiobuccal, mesiolingual and single mesial canals were: 0.34, 0.41 and 0.60 mm, respectively. The higher values of major diameters were found in the distobuccal canals (0.56 mm) and the lower diameters in the distolingual canals (0.29 mm). The lowest orifice distance was found between the mesial canals (MB-ML) and the highest distance between the distal root canals (DB-DL). Almost all distal roots had one root canal and one apical foramen with few accessory canals. Conclusions: Distolingual root generally has short length, severe curvature and a single root canal with low apical diameter.

Efficacy of CM-Wire, M-Wire, and Nickel-Titanium Instruments for Removing Filling Material from Curved Root Canals: A Micro-Computed Tomography Study.

INTRODUCTION: The aim of this ex vivo study was to evaluate the removal of filling material after using CM-wire, M-wire, and nickel-titanium instruments in both reciprocating and rotary motions in curved canals. METHODS: Thirty maxillary lateral incisors were divided into 9 groups according to retreatment procedures: Reciproc R25 followed by Mtwo 40/.04 and ProDesign Logic 50/.01 files; ProDesign R 25/.06 followed by ProDesign Logic 40/.05 and ProDesign Logic 50/.01 files; and Gates-Glidden drills, Hedström files, and K-files up to apical size 30 followed by K-file 40 and K-file 50 up to the working length. Micro-computed tomography scans were performed before and after each reinstrumentation procedure to evaluate root canal filling removal. Statistical analysis was performed with Kruskal-Wallis, Friedman, and Wilcoxon tests (P < .05). RESULTS: No significant differences in filling material removal were found in the 3 groups of teeth. The use of Mtwo and ProDesign Logic 40/.05 rotary files did not enhance filling material removal after the use of reciprocating files. The use of ProDesign Logic 50/.01 files significantly reduced the amount of filling material at the apical levels compared with the use of reciprocating files. CONCLUSIONS: Association of reciprocating and rotary files was capable of removing a large amount of filling material in the retreatment of curved canals, irrespective of the type of alloy of the instruments. The use of a ProDesign Logic 50/.01 file for apical preparation significantly reduced the amount of remnant material in the apical portion when compared with reciprocating instruments.

Avaliação em microCT do preparo dos canais mesiais de molares inferiores realizado por dois sistemas rotatórios de NiTi / Micro-CT evaluation of mesial canals preparation performed by two rotary NiTi systems in mandibular molars

Objetivo: avaliar em microCT a qualidade do preparo e desgaste das paredes mesiais e de furca de molares inferiores. Métodos: trinta molares inferiores humanos foram extraídos e escaneados em microCT. Os parâmetros analisados foram: centralização do canal radicular, extensão e direção do desvio na instrumentação, quantidade de dentina removida, espessura mínima de remanescente e os volumes apical e total antes e após instrumentação. Os dentes foram divididos em 3 grupos (n = 10): Grupo 1 = instrumentação com ProTaper até o instrumento F2; Grupo 2 = Twisted File, instrumento 25/08; Grupo 3 = instrumentação manual (controle). Resultados: não houve diferença significativa (p > 0,05) entre os sistemas rotatórios, em relação ao desvio na instrumentação, em todos os níveis analisados. O terço cervical apresentou maior quantidade de desvio na instrumentação quando comparado ao nível apical, e menor quantidade de remanescente, especialmente na zona de furca. Os sistemas removeram maior quantidade de dentina das paredes de furca (terço médio e cervical). Não houve diferença entre os grupos em relação à quantidade de dentina no terço apical. Os volumes apical e total não aumentaram significativamente após o preparo com os instrumentos rotatórios. Conclusão: os sistemas rotatórios de NiTi avaliados não aumentaram significativamente os volumes apical e total dos canais radiculares. O maior desvio na instrumentação ocorreu nos terços médio e cervical para todos os sistemas analisados. Para todos os grupos analisados, a quantidade de remanescente foi significativamente reduzida na direção da furca dos terços médio e cervical.

Sealing ability of MTA, CPM, and MBPc as root-end filling materials: a bacterial leakage study.

Objectives To evaluate the sealing ability of three root-end filling materials (white MTA, CPM, and MBPc) using an Enterococcus faecalis leakage model. Material and Methods Seventy single-root extracted human teeth were instrumented and root-ends were resected to prepare 3 mm depth cavities. Root-end preparations were filled with white MTA, CPM, and MBPc cements. Enterococcus faecalis was coronally introduced and the apical portion was immersed in BHI culture medium with phenol red indicator. The bacterial leakage was monitored every 24 h for 4 weeks. The statistical analysis was performed using the Wilcoxon-Gehan test (p<0.05). Results All cements showed bacterial leakage after 24 hours, except for the negative control group. The MBPc showed significantly less bacterial leakage compared with the MTA group (p<0.05). No significant differences were found between the CPM and the other groups. Conclusions The epoxy resin-based cement MBPc had lower bacterial leakage compared with the calcium silicate-based cements MTA and CPM.

Sealing ability of MTA, CPM, and MBPc as root-end filling materials: a bacterial leakage study

ABSTRACT Objectives To evaluate the sealing ability of three root-end filling materials (white MTA, CPM, and MBPc) using an Enterococcus faecalis leakage model. Material and Methods Seventy single-root extracted human teeth were instrumented and root-ends were resected to prepare 3 mm depth cavities. Root-end preparations were filled with white MTA, CPM, and MBPc cements. Enterococcus faecalis was coronally introduced and the apical portion was immersed in BHI culture medium with phenol red indicator. The bacterial leakage was monitored every 24 h for 4 weeks. The statistical analysis was performed using the Wilcoxon-Gehan test (p<0.05). Results All cements showed bacterial leakage after 24 hours, except for the negative control group. The MBPc showed significantly less bacterial leakage compared with the MTA group (p<0.05). No significant differences were found between the CPM and the other groups. Conclusions The epoxy resin-based cement MBPc had lower bacterial leakage compared with the calcium silicate-based cements MTA and CPM.

Low-concentrated nonvital bleaching effect on bond strength of composite resin restorations / Efeito de clareadores não-vitais pouco concentrados sobre a força de cisalhamento de restaurações de resina composta

Objective: To investigate if short-term dentin bleaching with low-concentrated substances affects the bond strength of immediate resin composite restorations. Material and Methods: The buccal surfaces of fifty molar crowns were ground for dentin exposure and randomly assigned into 5 groups (n=10), according to the following treatments: sodium perborate + water; sodium perborate + 6% hydrogen peroxide; 6% hydrogen peroxide; 35% hydrogen peroxide (positive control), or no bleaching agent (negative control). The specimens were immediately restored with resin composite. Seven days after treatments, the shear bond test was performed in a universal test machine at a crosshead speed of 0.5 mm/min. Data were analyzed using ANOVA and Tukey’s HSD test (α = 0.05). Results: The shear bond strength mean values for the negative control group were higher than all experimental and positive control groups (p < 0.000), whose differences were not statistically significant (p > 0.05). Conclusion: Short-term dentin bleaching with sodium perborate+water, 6% hydrogen peroxide, or sodium perborate mixed with 6% hydrogen peroxide reduced the shear bond strength of immediate resin composite restorations.

Objetivo: Investigar se o clareamento rápido da dentina com substâncias de baixa concentração afeta a resistência de união ao cisalhamento de restaurações imediatas de resina composta. Material e Métodos: As superfícies vestibulares de cinquenta molares foram desgastadas para exposição da dentina e então aleatoriamente alocadas em 5 grupos (n = 10), de acordo com as substâncias clareadoras: perborato de sódio + água; perborato de sódio + peróxido de hidrogênio a 6%; peróxido de hidrogênio a 6%; peróxido de hidrogênio a 35% (controle positivo); ou nenhum agente clareador (controle negativo). Os espécimes foram imediatamente restaurados com resina composta. Sete dias após os tratamentos, testes de resistência ao cisalhamento foram realizados em uma máquina de ensaios universal a uma velocidade de cruzeta de 0,5 mm/min. Os dados foram analisados com os testes ANOVA e Tukey HSD (α = 0,05). Resultados: Os valores de resistência ao cisalhamento do grupo controle negativo foram maiores do que os dos grupos experimentais e controle positivo (p < 0,001), cujas diferenças não foram estatisticamente significativa (p > 0,05). Conclusão: Clareamentos dentinários rápidos com perborato de sódio, peróxido de hidrogênio 6% ou perborato de sódio misturado com peróxido de hidrogênio 6% reduziram a força de resistência ao cisalhamento de restaurações imediatas de resina composta.

Influência do tipo de instrumento empregado para agitação ultrassônica na capacidade de remoção da smear layer / Influence of the type of instrument used in passive ultrasonic irrigation on the smear layer removal capacity

Introdução: o objetivo do presente estudo foi avaliar a capacidade de remoção da smear layer de limas manuais de aço inoxidável e de NiTi e de fio ortodôntico de NiTi, ativados pelo ultrassom. Métodos: 50 canais de raízes palatinas de molares superiores foram dilatados, no terço cervical, com a broca Laxxess 35 e, no terço apical, com o sistema ProTaper, até o instrumento F4, no comprimento real de trabalho. Os canais foram irrigados com hipoclorito de sódio a 1% e divididos em cinco grupos: GI = EDTA + ultrassom por 1 minuto com lima 15 do tipo K de aço inoxidável; GII = EDTA + ultrassom por 1 minuto com lima tipo K 15 de NiTi; GIII = EDTA + ultrassom por 1 minuto com fio ortodôntico #25 x 11 de NiTi; GIV = EDTA por 3 minutos sem agitação com ultrassom; GV = sem EDTA nem ultrassom. Posteriormente, cada raiz foi seccionada longitudinalmente e uma hemissecção foi metalizada e analisada em microscópio eletrônico de varredura, sendo feitas imagens de cada uma delas, nos três terços, estipulando-se os seguintes escores: 0 = nenhuma camada de detritos dentinários, com túbulos dentinários limpos e abertos; 1 = camada moderada de detritos dentinários; 2 = camada espessa de detritos dentinários, cobrindo a superfície dos túbulos dentinários. Os dados foram comparados estatisticamente. Resultados: após observar a smear layer nos três terços, verificou-se que todos os grupos que usaram o EDTA se diferenciaram estatisticamente (p < 0,05) do grupo sem EDTA. Não houve, porém, diferenças significativas entre os grupos com agitação ultrassônica e o grupo de EDTA sem ultrassom. Não houve diferenças significativas (p < 0,05) entre os três instrumentos empregados. Conclusão: o uso do EDTA favoreceu a remoção da smear layer. A ativação ultrassônica do EDTA por 1 minuto, independentemente do instrumento empregado, favoreceu a obtenção de paredes mais limpas.

Análisis comparativo de la extrusión apical de dentina producida por diferentes técnicas de instrumentación / Comparative analysis of dentin apical extrusion through different root canal techniques

Objetivo. El propósito de este estudio fue comparar el material sólido extruido por el foramen apical usando las técnicas manuales Step Back, regon y las rotatorias, Sistema K3 Endo, Sistemas Protaper y sistema F.K.G. RaCe. Material y métodos. Sesenta y cinco dientes unirradiculares fueron utilizados siendo 15 para cada uno de los grupos. El material extruído en las diferentes técnicas fue recogido en papel de filtro (Whatman®) sometidos a secado en estufa y pesado en balanza digital de alta precisión. A través del test ANOVA se observó la diferencia existente entre los diferentes grupos estudiados y el test paramétrico de Tukey fue aplicado para el análisis comparativo de los grupos entre sí. Resultados. El análisis de los resultados mostró extrusión de material por el foramen en todas las técnicas testadas.siendo que Step Back promovió la mayor cantidad de material extruido siendo significante en relación a las demás que fueron equivalentes estadísticamente. Conclusiones. No fue observada diferencia significativa entre la técnica de Oregon y las rotatorias siendo que entre estas el sistema K3 Endo proporcionó el menor índice de extrusión (AU)

Objective. The purpose of this study was to conpare the solid material extruded through the apical foramen using manual techniques Step Back, Oregon and rotary systems: K3 Endo, ProTaper and FKG RaCe. Material and methods. Sixty-five single-root teeth were used with 15 for each of the groups. The extruded material of different techniques was collected in filter paper (Whatman®) submitted to oven drying and weighing in high precision digital scale. Through ANOVA test was observed the difference between the different studied groups and the Tukey parametric test was applied to the comparative analysis of the groups together. Results. The analysis of the results showed extrusion material through the foramen in all techniques. Step Back promoted the most significant being extruded material in relation to the others that were statistically equivalent.Conclusions. No significant difference was observed between the technique of Oregon and rotary systems; among these being that K3 Endo system provided the lowest rate of extrusion (AU)

Micro-computed tomography analysis of the root canal anatomy and prevalence of oval canals in mandibular incisors.

INTRODUCTION: This study aimed to describe the anatomy of the mandibular incisors by using micro-computed tomography. METHODS: Mandibular incisors (n = 340) were scanned at 19-µm voxel size resolution, and the numbers of canals were classified according to Vertucci classification, as well as the major and minor diameters of the root and root canals, presence of oval canals, and three-dimensional analysis of the apical third were also measured. Data were presented in terms of median and range for each anatomic classification. RESULTS: Overall, the specimens had 1 root canal (N = 257). The second most prevalent anatomy was Vertucci type III (N = 56). These anatomies represent 92% of the sample. The medians of the major diameter at the 1-, 2-, and 3-mm level of the most prevalent anatomies were 0.36, 0.39, and 0.47 mm for type I and 0.41, 0.51, and 0.66 mm for type III, respectively. The apical volume appears to be constant among these anatomies (0.63 and 0.59 mm(3)). Oval canals were found at the 1-mm apical level, with a prevalence of 16.7% for Vertucci type I and 37.5% for Vertucci type III. The presence of oval canals increased at the 3-mm apical level to 32.4% and 76.2% for Vertucci type I and III classifications, respectively. CONCLUSIONS: Type I and III configurations represent 92% of the mandibular incisors studied. Within these anatomic configurations, oval-shaped canals in the apical third were not uncommon and more prevalent in the type III anatomy.

Biocompatibility and setting time of CPM-MTA and white Portland cement clinker with or without calcium sulfate.

OBJECTIVE: To evaluate the biocompatibility and the setting time of Portland cement clinker with or without 2% or 5% calcium sulfate and MTA-CPM. MATERIAL AND METHODS: Twenty-four mice (Rattus norvegicus) received subcutaneously polyethylene tubes filled with Portland cement clinker with or without 2% or 5% calcium sulfate and MTA. After 15, 30 and 60 days of implantation, the animals were killed and specimens were prepared for microscopic analysis. For evaluation of the setting time, each material was analyzed using Gilmore needles weighing 113.5 g and 456.5 g, according to the ASTM specification Number C266-08 guideline. Data were analyzed by ANOVA and Tukey's test for setting time and Kruskal-Wallis and Dunn test for biocompatibility at 5% significance level. RESULTS: Histologic observation showed no statistically significant difference of biocompatibility (p>0.05) among the materials in the subcutaneous tissues. For the setting time, clinker without calcium sulfate showed the shortest initial and final setting times (6.18 s/21.48 s), followed by clinker with 2% calcium sulfate (9.22 s/25.33 s), clinker with 5% calcium sulfate (10.06 s/42.46 s) and MTA (15.01 s/42.46 s). CONCLUSIONS: All the tested materials showed biocompatibility and the calcium sulfate absence shortened the initial and final setting times of the white Portland cement clinker.

Antimicrobial activity of calcium hydroxide and chlorhexidine on intratubular Candida albicans.

This study investigated the efficacy of calcium hydroxide and chlorhexidine gel for the elimination of intratubular Candida albicans (C. albicans). Human single-rooted teeth contaminated with C. albicans were treated with calcium hydroxide, 2% chlorhexidine gel, calcium hydroxide plus 2% chlorhexidine gel, or saline (0.9% sodium chloride) as a positive control. The samples obtained at depths of 0-100 and 100-200 µm from the root canal system were analyzed for C. albicans load by counting the number of colony forming units and for the percentage of viable C. albicans using fluorescence microscopy. First, the antimicrobial activity of calcium hydroxide and the 2% chlorhexidine gel was evaluated by counting the number of colony forming units. After 14 days of intracanal medication, there was a significant decrease in the number of C. albicans colony forming units at a depth of 0-100 µm with chlorhexidine treatment either with or without calcium hydroxide compared with the calcium hydroxide only treatment. However, there were no differences in the number of colony forming units at the 100-200 µm depth for any of the medications investigated. C. albicans viability was also evaluated by vital staining techniques and fluorescence microscopy analysis. Antifungal activity against C. albicans significantly increased at both depths in the chlorhexidine groups with and without calcium hydroxide compared with the groups treated with calcium hydroxide only. Treatments with only chlorhexidine or chlorhexidine in combination with calcium hydroxide were effective for elimination of C. albicans.

Análise microscópica de incisões realizadas com três diferentes pontas do laser Erbio YAG / Microscopic evaluation of incision with three different Er-YAG laser tips

Analisou-se microscopicamente o processo de reparo de incisões realizadas na derme de ratos, utilizando três pontas diferentes do laser de Erbio YAG. Foram selecionados 6 ratos, nos quais, após depilação da região dorsal e anestesia, foram submetidos a incisões com o Laser Erbio-YAG, utilizando as peças de mão 2051, peça de mão 2055 com fibra óptica de forma cilíndrica e peça de mão 2056 com fibra óptica de forma de espátula. Os animais foram mortos após 7 e 14 dias, sendo que nesse momento, as feridas incisionais foram fotografadas. As peças contendo a região incisada foram preparadas para análise microscópica, realizando-se secções de 7µm e coloração com hematoxilina e eosina. Avaliou-se a zona de ablação tecidual, zona de necrose térmica, presença e característica das células inflamatórias e o processo de reparo. A peça de mão 2051 foi a que propiciou corte mais rápido e produziu bordas de ferida mais definidas. Para realizar uma incisão de 1.30 mm de profundidade foi necessário passar as peças de mão do laser cinco vezes no mesmo local. Não houve diferença no processo de reparo nas incisões realizadas com os três tipos de peças de mão do laser de Erbio Yag

The study analised microscopic wound healing of incision made with Er:YAg laser with three different tips. In six Rattus norvegicus, incision was made with Laser Er-YAG (KeyLaser) using tips 2051, 2055 and 2056. The animals were killed at 7 e 14 and the sites of incision are photographed in this time. The parts containing the incision area were prepared for microscopic analysis, performing sections of 7µm and staining with haematoxylin and eosin. Zone of tissue ablation, zone of thermal necrosis, the presence and character of inflammatory cell infiltrate and wound healing were measured. The 2051 tip produced faster and defined edges of the wound. To create wound 1.30 mm in depth lasers tips required at last five passes within the same line of incision. Microscopic analysis shows no difference with use of three different laser tips

The antimicrobial effect of new and conventional endodontic irrigants on intra-orally infected dentin.

OBJECTIVES: To evaluate if the incorporation of antimicrobial compounds to chelating agents or the use of chelating agents with antimicrobial activity as 7% maleic acid and peracetic acid show similar disinfection ability in comparison to conventional irrigants as sodium hypochlorite or iodine potassium iodide against biofilms developed on dentin. MATERIALS AND METHODS: The total bio-volume of live cells, the ratio of live cells and the substratum coverage of dentin infected intra-orally and treated with the irrigant solutions: MTAD, Qmix, Smear Clear, 7% maleic acid, 2% iodine potassium iodide, 4% peracetic acid, 2.5% and 5.25% sodium hypochlorite was measured by using confocal microscopy and the live/dead technique. Five samples were used for each irrigant solution. RESULTS: Several endodontic irrigants containing antimicrobials as clorhexidine (Qmix), cetrimide (Smear Clear), maleic acid, iodine compounds or antibiotics (MTAD) lacked an effective antibiofilm activity when the dentin was infected intra-orally. The irrigant solutions 4% peracetic acid and 2.5-5.25% sodium hypochlorite decrease significantly the number of live bacteria in biofilms, providing also cleaner dentin surfaces (p < 0.05). CONCLUSIONS: Several chelating agents containing antimicrobials could not remove nor kill significantly biofilms developed on intra-orally infected dentin, with the exception of sodium hypochlorite and 4% peracetic acid. Dissolution ability is mandatory for an appropriate eradication of biofilms attached to dentin.

Antimicrobial activity of triantibiotic paste, 2% chlorhexidine gel, and calcium hydroxide on an intraoral-infected dentin biofilm model.

INTRODUCTION: The purpose of this study was to evaluate the antimicrobial activity of calcium hydroxide, 2% chlorhexidine gel, and triantibiotic paste (ie, metronidazole, minocycline, and ciprofloxacin) by using an intraorally infected dentin biofilm model. METHODS: Forty bovine dentin specimens were infected intraorally using a removable orthodontic device in order to induce the biofilm colonization of the dentin. Then, the samples were treated with the medications for 7 days. Saline solution was used as the control. Two evaluations were performed: immediately after the elimination of the medication and after incubation in brain-heart infusion medium for 24 hours. The Live/Dead technique (Invitrogen, Eugene, OR) and a confocal microscope were used to obtain the percentage of live cells. Nonparametric statistical tests were performed to show differences in the percentage of live cells among the groups (P < .05). RESULTS: Calcium hydroxide and 2% chlorhexidine gel did not show statistical differences in the immediate evaluation. However, after application of the brain-heart infusion medium for 24 hours, 2% gel chlorhexidine showed a statistically lesser percentage of live cells in comparison with calcium hydroxide. The triantibiotic paste significantly showed a lower percentage of live cells in comparison with the 2% chlorhexidine gel and calcium hydroxide groups in the immediate and secondary (after 24 hours) evaluations. CONCLUSIONS: The triantibiotic paste was most effective at killing the bacteria in the biofilms on the intraorally infected dentin model in comparison with 2% chlorhexidine gel and calcium hydroxide.