title: Evaluation and comparison of 2 needle models in terms of blood aspiration during truncal block of the inferior alveolar nerve.
abstract: OBJECTIVE
  We conducted a study to determine the possible differences in blood aspiration between 2 needles of the same length and external gauge but with different internal gauges during truncal block of the inferior alveolar nerve. The working hypothesis was that increased blood aspiration may be expected with larger internal gauge needles.
  
  
  METHODS
  Four clinicians subjected 346 patients to inferior alveolar nerve block and infiltrating anesthesia of the buccal nerve trajectory for the surgical or conventional extraction of the lower third molar. A nonautoaspirating syringe system with 2 types of needle were used: a standard 27-gauge x 35-mm needle with an internal gauge of 0.215 mm and an XL Monoprotect (manufactured by Sofic, Mazamet, France, and distributed by Laboratorios Inibsa, Barcelona, Spain) 27-gauge x 35-mm needle with an internal gauge of 0.265 mm. The following information was recorded for each patient: needle type, gender, anesthetic technique (direct or indirect truncal block) and the number of bone contacts during the procedure, the patient-extraction side, the operator performing the technique, and blood aspiration (either positive or negative).
  
  
  RESULTS
  No significant differences (P <.05) were observed on contrasting the blood aspiration positivity with the internal gauge of the needles. Likewise, no significant differences were seen on correlating aspiration to the anesthetic technique used, the number of bone contacts, the operator, or the patient-extraction side. Blood aspiration was observed in 8.7% of cases.
  
  
  CONCLUSIONS
  No significant differences were recorded in terms of blood aspiration and internal gauge, operator, patient-extraction side, or the anesthetic technique involved. Consequently, our initial working hypothesis can be rejected, because no increased percentage of blood aspirations was observed for greater internal gauges.
authors.affiliation: Oral Surgery and Implantology, Barcelona University Dental School, Barcelona, Spain.
authors.forename: Esther
authors.initials: E
authors.lastname: Delgado-Molina
authors.forename: Meritxell
authors.initials: M
authors.lastname: Tamarit-Borrás
authors.forename: Leonardo
authors.initials: L
authors.lastname: Berini-Aytés
authors.forename: Cosme
authors.initials: C
authors.lastname: Gay-Escoda
mesh_terms: D000328:Adult; D000766:Anesthesia, Dental / Q000295:instrumentation*; D001769:Blood; D004867:Equipment Design; D005260:Female; D006801:Humans; D008297:Male; D008340:Mandibular Nerve; D009339:Needles; D009407:Nerve Block / Q000295:instrumentation*; D013594:Syringes; D014081:Tooth Extraction