title: Does ultra-pulse CO(2) laser reduce the risk of enamel damage during debonding of ceramic brackets?
abstract: This study seeks to evaluate the enamel surface characteristics of teeth after debonding of ceramic brackets with or without laser light. Eighty premolars were bonded with either of the chemically retained or the mechanically retained ceramic brackets and later debonded conventionally or through a CO(2) laser (188 W, 400 Hz). The laser was applied for 5 s with scanning movement. After debonding, the adhesive remnant index (ARI), the incidence of bracket and enamel fracture, and the lengths, frequency, and directions of enamel cracks were compared among the groups. The increase in intrapulpal temperature was measured in ten extra specimens. The data were analyzed with SPSS software. There was one case of enamel fracture in the chemical retention/conventional debonding group. When brackets were removed with pliers, incidences of bracket fracture were 45% for the chemical retention, and 15% for the mechanical retention brackets. No case of enamel or bracket fracture was seen in the laser-debonded teeth. A significant difference was observed in ARI scores among the groups. Laser debonding caused a significant decrease in the frequency of enamel cracks, compared to conventional debonding. The increase in intrapulpal temperatures was below the benchmark of 5.5 °C for all the specimens. Laser-assisted debonding of ceramic brackets could reduce the risk of enamel damage and bracket fracture, and produce the more desirable ARI scores without causing thermal damage to the pulp. However, some augmentations in the length and frequency of enamel cracks should be expected with all debonding methods.
authors.affiliation: Dental Materials Research Center, School of Dentistry, Mashhad University of Medical Sciences, Mashhad, Iran. Farzaneganf@mums.ac.ir
authors.forename: Farzaneh
authors.initials: F
authors.lastname: Ahrari
authors.forename: Farzin
authors.initials: F
authors.lastname: Heravi
authors.forename: Reza
authors.initials: R
authors.lastname: Fekrazad
authors.forename: Fahimeh
authors.initials: F
authors.lastname: Farzanegan
authors.forename: Samaneh
authors.initials: S
authors.lastname: Nakhaei
mesh_terms: D002516:Ceramics; D003738:Dental Cements; D017005:Dental Debonding / Q000009:adverse effects / Q000379:methods*; D003743:Dental Enamel / Q000293:injuries / Q000528:radiation effects*; D003799:Dental Stress Analysis; D006801:Humans; D066298:In Vitro Techniques; D054020:Lasers, Gas / Q000627:therapeutic use*; D028022:Low-Level Light Therapy; D016910:Orthodontic Brackets; D012307:Risk Factors; D013696:Temperature; D014082:Tooth Fractures / Q000517:prevention & control
chemical_list: D003738:Dental Cements