title: Clinical evaluation of bond failures and survival between mandibular canine-to-canine retainers made of flexible spiral wire and fiber-reinforced composite.
abstract: OBJECTIVE
  The purpose of this longitudinal prospective randomized study was to evaluate the clinical reliability of two different types of postorthodontic treatment retainers: a silanised-treated glass fibers-reinforced resin composite (FRC) and a directly bonded multistranded stainless steel wire. The hypothesis of the study was to assess if significant differences are present between failure rates of the two retainers.
  
  
  METHODS
  This prospective study was based on an assessment of 87 patients (35 men and 52 women),with an average age of 24 years who required a lower arch fixed retainer after orthodontic treatment. Patients were divided in two groups. Assignment was carried out with random tables. A follow-up examination was carried out once a month. The number, cause, and date of single bond adhesive failures were recorded for both retainers over 12 months. Teeth that were rebonded after failure were not included in the success analysis. Statistical analysis was performed by means of a Fisher's exact test, Kaplan-Meier survival estimates, and log rank test.
  
  
  RESULTS
  Bond failure rate was significantly higher (P=0.0392) for multistranded metallic wire than for FRC.
  
  
  CONCLUSIONS
  Glass fiber-reinforced resin composite retainers and multistranded metallic wires showed no significant difference in single bond failure rates over a one-year follow up. Key words:Fiber reinforced composite, fixed retention, multistranded wire, orthodontics, retainer, splint.
authors.affiliation: MD, DDS, PhD. Università degli Studi di Pavia - Dipartimento di Scienze Clinico-Chirurgiche, Diagnostiche e Pediatriche, Sezione di Odontoiatria, UDA di Ortognatodonzia e Odontoiatria Infantile. Italy.
authors.forename: Maria F
authors.initials: MF
authors.lastname: Sfondrini
authors.affiliation: MD, PhD. Università degli Studi di Pavia - Dipartimento di Scienze Clinico-Chirurgiche, Diagnostiche e Pediatriche, Sezione di Odontoiatria, UDA di Ortognatodonzia e Odontoiatria Infantile. Italy.
authors.forename: Danilo
authors.initials: D
authors.lastname: Fraticelli
authors.affiliation: DDS. Università degli Studi di Pavia - Dipartimento di Scienze Clinico-Chirurgiche, Diagnostiche e Pediatriche, Sezione di Odontoiatria, UDA di Ortognatodonzia e Odontoiatria Infantile. Italy.
authors.forename: Linda
authors.initials: L
authors.lastname: Castellazzi
authors.affiliation: DDS, PhD. Università degli Studi di Pavia - Dipartimento di Scienze Clinico-Chirurgiche, Diagnostiche e Pediatriche, Sezione di Odontoiatria, UDA di Ortognatodonzia e Odontoiatria Infantile. Italy.
authors.forename: Andrea
authors.initials: A
authors.lastname: Scribante
authors.affiliation: MD, DDS. Università degli Studi di Pavia - Dipartimento di Scienze Clinico-Chirurgiche, Diagnostiche e Pediatriche, Sezione di Odontoiatria, UDA di Ortognatodonzia e Odontoiatria Infantile. Italy.
authors.forename: Paola
authors.initials: P
authors.lastname: Gandini