Influência do diâmetro foraminal do canal radicular, do tipo e da penetração de agulha, e do fluxo da solução irrigadora na limpeza e na extrusão apical

Abstract

Influência do diâmetro foraminal do canal radicular, do tipo e da penetração de agulha, e do fluxo da solução irrigadora na limpeza e na extrusão apical Descritores: Endodontia; irrigantes do canal radicular; radiologia. Abstract Introduction:The root canal irrigation aims to clean and disinfect the root canal system, without causing apical extrusion. Objective: To evaluate the influence of apical foramen diameter, needle penetration depth and needle design, and the irrigating solution flow rate on the cleaning and apical extrusion. Material and method: Roots of human mandibular incisors with single-canal were instrumented and after enlarged with two different root apical sizes (40 and 60 K-files), the root canals were filled with contrast solution thickened with propylene glycol and zinc oxide. Two types of irrigation needles (27-gauge) with different designs (apical or lateral opening) were used, two flow rates corresponding to 15 or 25 mL/min and needle penetration at two depths (3 and 6 mm from the apex). Before and after irrigation, the teeth were radiographed using a digital radiographic system. Pre-irrigation (canals filled with contrast) and post-irrigation (canals with remaining contrast) images were submitted to digital subtraction using the Adobe Photoshop CS4 software and the areas were measured using the Image Tool 3.0 software, obtaining the percentage of cleaning and extrusion. Data obtained were subjected to one-way ANOVA and Tukey's tests with the significance level of 5%. Result: There was no statistical difference between the apical foramen diameter, needle penetration depth and needle design, and the irrigating solution flow rate on the cleaning results (more than 97%) and the level of apical extrusion (less than 0.38 mm 2 ), (p>0,05). Conclusion: All irrigation protocols evaluated provided cleaning of the root canal and low apical extrusion of irrigating solution.

Effect of apical expansion in decreasing microorganisms: a literature review

“…In a study by Tanomaru-Filho et al, 23 12 mandibular incisors were instrumented and, after foraminal enlargement with different diameters (#40 and #60), the root canals were filled with radiopaque solution thickened with propylene glycol and zinc oxide. Two types of irrigation 27G needles were used, with different designs (apical or side opening), with two streams corresponding to 15 or 25 mL/min, and penetration of the needles in two depths (3 and 6 mm short from the apex).…”

“…19,20,22 Removal of smear layer formed after chemical-mechanical preparation, both in manual and mechanical instrumentation, does not raise major concerns, since, with proper enlargement of the cervical, medium and apical thirds and the use of needles with ideal gauge for irrigation, thus allowing insertion near foramen, it allows effective irrigation and removal of debris, thereby decreasing extrusion. 23 The trauma of foramen overinstrumentation, causing disorganization of periapical tissues, does not lead to postoperative sensitivity, regardless of pulp tissue vitality, thus demonstrating that the chemicalmechanical preparation procedure may involve the cemental canal without postinstrumentation consequences to the patient.…”