Factors affecting irrigant extrusion during root canal irrigation: a systematic review

The aim of the present study was to conduct a systematic review and critical analysis of published data on irrigant extrusion to identify factors causing, affecting or predisposing to irrigant extrusion during root canal irrigation of human mature permanent teeth. An electronic search was conducted in Cochrane Library, LILACS, PubMed, SciELO, Scopus and Web of Knowledge using a combination of the terms ‘irrigant’, ‘rinse’, ‘extrusion’, ‘injection’, ‘complication’, ‘accident’, ‘iatrogenic’, ‘root canal’, ‘tooth’ and ‘endodontic’. Additional studies were identified by hand‐searching of six endodontic journals and the relevant chapters of four endodontic textbooks, resulting in a total of 460 titles. No language restriction was imposed. After applying screening and strict eligibility criteria by two independent reviewers, 40 case reports and 10 ex vivo studies were included in the review. A lack of clinical studies focusing on irrigant extrusion during root canal irrigation was evident. The reviewed case reports focused mainly on the clinical manifestations and management of the accidents and did not provide adequate details on the possible factors that may influence irrigant extrusion. The data from the included ex vivo studies were inconclusive due to major methodological limitations, such as not simulating the presence of periapical tissues and not assessing the validity of irrigant detection methods. The extensive variability in the protocols employed hindered quantitative synthesis. The choice of factors investigated in ex vivo studies seems not to have been driven by the available clinical evidence. These issues need to be addressed in future studies.     

Irrigant flow within a prepared root canal using various flow rates: a Computational Fluid Dynamics study

Aim  To study using computer simulation the effect of irrigant flow rate on the flow pattern within a prepared root canal, during final irrigation with a syringe and needle.
Methodology  Geometrical characteristics of a side-vented endodontic needle and clinically realistic flow rate values were obtained from previous and preliminary studies. A Computational Fluid Dynamics (CFD) model was created using FLUENT 6.2 software. Calculations were carried out for five selected flow rates (0.02–0.79 mL sec⁻¹) and velocity and turbulence quantities along the domain were evaluated.
Results  Irrigant replacement was limited to 1–1.5 mm apical to the needle tip for all flow rates tested. Low-Reynolds number turbulent flow was detected near the needle outlet. Irrigant flow rate affected significantly the flow pattern within the root canal.
Conclusions  Irrigation needles should be placed to within 1 mm from working length to ensure fluid exchange. Turbulent flow of irrigant leads to more efficient irrigant replacement. CFD represents a powerful tool for the study of irrigation.     

Peripheral osteoma of the maxilla: report of an unusual case.

Peripheral osteomas of the maxilla are relatively rare. A case of a solitary peripheral osteoma of the anterior right maxilla in a 16-year-old girl is presented. The tumor was asymptomatic and was removed via an intraoral approach without any complications. Both hamartomatous and neoplastic factors have been advocated concerning the pathogenesis of such lesions, but no definite conclusion has been reported. Certain features of the case, such as obstruction of the eruption of the permanent canine, displacement of an adjacent tooth, intraoperatively noted infiltration of the interdental bone, and clearly abnormal histological bone structure might support the neoplastic nature of this lesion.     

Influence of smear layer on depth of penetration of three endodontic sealers: an SEM study

Abstract— The purpose of this study was to examine the effect of the smear layer on the penetration depth of Sealapex, Roth 811, and CRCS root canal sealers into the dentinal tubules. Forty recently extracted, human single-rooted teeth were used. The crowns were cut and removed at the cemento-enamel junction level and the root canals were prepared to a #60 K-file. The teeth were then randomly divided into two groups of 20, group A and group B. The smear layer was removed from all teeth in group A with EDTA and NaOCl. The smear layer remained in all teeth in group B. Two roots in each group were used as controls. Six roots from each group were obturated with Roth 811 sealer and gutta-percha through lateral condensation. The same process was repeated using sealers CRCS and Sealapex. Each root was then divided in two and prepared for scanning electron microscope observation. The removal of the smear layer allowed penetration of all three sealers into the dentinal tubules to a depth of between 35 μm and 80 μm. Although the CRCS sealer penetrated only up to the 35 mm point, it offered better or complete obturation of the dentinal tubules. The presence of smear layer at the root canal walls obstructed the penetration of all sealers into the dentinal tubules.