Effect of ethanol-conditioned dentine on sealer penetration into dentinal tubules: a confocal microscopy study

Aim: The aim of this study was to evaluate the effect of ethanol-conditioned dentin on endodontic sealer penetration into dentinal tubules by confocal laser scanning microscopy (CLSM). Methods: Forty human maxillary anterior teeth were instrumented and divided into four groups (n = 10) according to the drying methods: 1) wet: vacuum only, 2) paper points: vacuum + absorbent paper points, (3) 70% ethanol: 70% ethanol (1 min) + vacuum + absorbent paper points, and (4) 100% ethanol: 100% ethanol (1 min) + vacuum + absorbent paper points. All root canals were filled with resin-based endodontic sealer. Four sections from each third (cervical, middle, and apical) were examined by CLSM. Root canal wall perimeter infiltrated by sealer, maximum depth of sealer penetration, percentage of penetrated area, and fluorescence intensity of rhodamine B were measured. Statistical analysis was performed by analysis of variance and Tukey's tests (α = 0.05). Results: No statistical difference was found when percentage of root canal wall coverage infiltrated by sealer were compared. The groups in which ethanol solutions were used presented greater depth of sealer penetration, higher percentage of penetrated area, and higher fluorescence intensity of rhodamine B (p< 0.05) when compared with the wet and paper point groups. Overall, 100% ethanol produced better results than 70% ethanol, except for rhodamine B intensity (cervical third). In addition, the absorbent paper points drying method behaved better than did vacuum only group, except for rhodamine B intensity (apical third). Conclusion: Ethanol-conditioned dentin improved the penetration of resin-based sealer into dentinal tubules, especially at the concentration of 100%

Influence of ethanol on dentin roughness, surface free energy, and interaction between AH Plus and root dentin

Abstract This study aimed to evaluate the influence of different ethanol concentrations on dentin roughness, surface free energy, and contact angle between AH Plus and the root canal dentin. One hundred human maxillary anterior teeth were split longitudinally and 200 dentin specimens were polished to make the surface flatter and smoother. An acrylic bar was positioned between two dentin specimens and impression material was added to create a block, simulating an instrumented root canal space. Specimens were removed from the mold and cleaned in an ultrasonic bath for 10 min. Thereafter, dentin specimens were divided into four groups (n = 50) according to the drying methods used: a) wet: vacuum only, b) paper points: vacuum + absorbent paper points, c) 70% alcohol: 70% alcohol (1 min) + vacuum + absorbent paper points, and d) 100% alcohol: 100% alcohol (1 min) + vacuum + absorbent paper points. A rugosimeter and a goniometer were used to verify the roughness (Ra) and to measure the surface free energy and the contact angle between the AH Plus sealer and the root canal dentin. ANOVA and Tukey tests (α = 0.05) were used for statistical analysis. The 70% and 100% ethanol groups showed significantly decreased roughness as well as increased surface free energy in the root canal dentin when compared to the wet and paper point groups. In addition, ethanol significantly reduced the contact angle between the AH Plus sealer and the root canal dentin. Ethanol solutions (70% and 100%) provide better wettability of AH Plus sealer on dentin surfaces.

Remoção de retentores metálicos intrarradiculares com o Saca-pinos M&V: relato de casos clínicos / Removal of intraradicular cast posts with M&V device: clinical cases report

O endodontista em sua clínica diária depara-se, com alguma frequência, com a necessidade de realização do retratamento endodôntico e, muitas vezes, previamente a esse procedimento, faz-se necessária a remoção de retentores intrarradiculares. Diversos aparelhos são disponibilizados no mercado com a finalidade de promover o tracionamento do retentor intrarradicular. Dentre eles, destaca-se o Saca-pinos M&V®, que pode ser utilizado isoladamente ou associado a outras técnicas previamente à tração. Nesse sentido, o presente trabalho relata dois casos clínicos distintos, que descrevem o uso desse dispositivo, suas vantagens, limitações e a influência de outras técnicas durante a remoção.

The endodontist, in his daily clinical, encounters himself with some frequency with the necessity of endodontic retreatment. So, sometimes it is necessary to remove intraradicular cast posts previously to this procedure. Thus, some devices are available in market aiming to pull the pin to be removed. Among them, stands out the M&V® device, which can be used singly or associated with other procedures previously to the tension. In this way, the present study relates two case reports, which describe this device use, including the advantages and limitations. In addition, the cases reports are compared each other showing the advantage of using this device with technical association.

Effect of the smear layer on the filling of artificial lateral canals and microleakage

Aim: To evaluate the influence of the smear layer on the filling and prevention of microleakage in artificial lateral canals after use of different irrigating solutions. Methods: Two lateral canals were produced in 44 human dental roots with drills of 0.1 mm in diameter. The roots were divided in 4 groups according to the irrigation protocol: GI - 0.9% saline solution (control); GII - 2.5% sodium hypochlorite + 17% EDTA; GIII - 2% chlorhexidine gel + 17% EDTA; GIV - 2% chlorhexidine solution + 17% EDTA. Four roots were used as negative (n=2) and positive (n=2) controls. Lateral condensation technique and AH Plus were used to fill the root canals. Digital buccolingual radiographs were exposed and after the sealer had set, the roots were immersed in Indian ink dye and then cleared in methyl salicylate. The extent of filling and microleakage were measured and the values analyzed statistically. Results: No difference was found in the percentage of filling and microleakage among the groups, regardless of the location of the artificial lateral canals and the irrigation protocol used. Twenty percent of lateral canals produced no radiographic images, but their filling was confirmed using the clearing technique. Conclusions: The presence or absence of the smear layer did not affect the filling ability and the prevention of microleakage in artificial lateral canals.