title: Comparison of new and 3-month-old toothbrushes in plaque removal.
abstract: OBJECTIVE
  It is often recommended that manual toothbrushes should be replaced every 3 months. The aim of this study was to compare the effectiveness of new and 3-month-old toothbrushes in the removal of dental plaque.
  
  
  METHODS
  A single examiner blind, randomized study was performed in which 40 adult patients attended the clinic on two occasions following 48-h periods of no oral hygiene. Following plaque scoring, patients brushed with a new toothbrush at one visit and with a brush that they had used previously for 3 months at the other visit. Brushing time was 60 s. Plaque was then re-scored and percentage reductions in plaque scores calculated. The amount of wear of the 3-month-old brushes was determined by measurement of brushing surface areas.
  
  
  RESULTS
  Plaque scores after each 48-h period of no oral hygiene were not significantly different. The percentage reductions in plaque scores achieved with the new brushes were not significantly different from those achieved with the 3-month-old brushes. Both the new and the 3-month-old toothbrushes reduced plaque scores by approximately 34%. Compared with new brushes in the same subjects, no significant differences were found for plaque score reductions for 3-month-old brushes with minor, moderate or marked wear.
  
  
  CONCLUSIONS
  The 3-month-old toothbrushes were as effective as new brushes in plaque removal.
mesh_terms: D000328:Adult; D016001:Confidence Intervals; D003773:Dental Plaque / Q000628:therapy*; D003774:Dental Plaque Index; D004867:Equipment Design; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D016555:Matched-Pair Analysis; D008875:Middle Aged; D016037:Single-Blind Method; D013499:Surface Properties; D013997:Time Factors; D014099:Toothbrushing / Q000295:instrumentation*