Resumo

LOIOLA, Livia Etchebehere de; GUERREIRO-TANOMARU, Juliane Maria; MORGENTAL, Renata Dornelles  e  TANOMARU FILHO, Mário. Influence of the endodontic irrigation needle and root canal enlargement on endodontic cleaning efficacy. RSBO (Online) [online]. 2011, vol.8, n.2, pp. 138-144. ISSN 1984-5685.

INTRODUCTION: The irrigation of root canals aims to their cleaning and disinfection, improving endodontic treatment success. OBJECTIVE: To investigate the influence of the diameter and type of irrigation needle and the root canal enlargement on the mechanical efficacy of endodontic irrigation. MATERIAL AND METHODS: Twelve human single-rooted mandibular incisors were used. During some instrumentation stages (enlargement by #20, #30, and #40 K file), root canals were filled with radiographic contrast solution mixed to propyleneglycol and zinc oxide. Needles with different diameters and designs were employed: G1 - 23G and lateral opening; G2 - 22G and apical opening; G3 - 30G and lateral opening; G4 - 30G and apical opening. The needles were inserted up to resistance, with 1 mm step-back to avoid root canal obliteration. The irrigation was performed with 2 mL of distilled water. Before and after irrigation/aspiration, teeth were radiographed at bucco-lingual and mesiodistal direction, using a digital radiographic system. Then, root canal areas, before (filled by contrast solution) and after irrigation (remnant of contrast solution), were submitted to image subtraction with Adobe Photoshop CS4 software. Subsequently, the areas were measured by Image Tool 3.0 software, allowing the obtaining of the cleaning percentage for each modality. Data were analysed by using Anova and Tukey's test. The level of significance was set at P < 0.05. RESULTS: For all root canal enlargements, 30G needles (G3 e G4) presented a better cleaning efficacy. In all groups, higher cleaning efficacy percentage was observed at #30 and #40 K file enlargement. CONCLUSION: Regardless their design, thinner needles were more effective; a better cleaning efficacy occurred in more enlarged root canals.

Palavras-chave : needles; Endodontics; root canal irrigants.