title: Fracture Forces of Dentin after Surface Treatment with High Speed Drill Compared to Er:YAG and Er,Cr:YSGG Laser Irradiation.
abstract: Dental tooth restorative procedures may weaken the structural integrity of the tooth, with the possibility of leading to fracture. In this study we present findings of coronal dentin strength after different techniques of surface modification. The fracture strength of dentin beams after superficial material removal with a fine diamond bur high speed drill hand piece, Er:YAG (2.94 μm, 8 J/cm(2)), and Er,Cr:YSGG (2.78 μm, 7.8 J/cm(2)) laser irradiation slightly above the ablation threshold was measured by a four-point bending apparatus. Untreated dentin beams served as a control. A total of 58 dentin beams were manufactured from sterilized human extracted molars using the coronal part of the available dentin. Mean values of fracture strength were calculated as 82.0 ± 27.3 MPa for the control group (n = 10), 104.5 ± 26.3 MPa for high speed drill treatment (n = 10), 96.1 ± 28.1 MPa for Er,Cr:YSGG laser irradiation (n = 20), and 89.1 ± 36.3 MPa for Er:YAG laser irradiation (n = 18). Independent Student's t-tests showed no significant difference between each two groups (p > 0.05). Within the parameter settings and the limits of the experimental setup used in this study, both lasers systems as well as the high speed drill do not significantly weaken coronal dentin after surface treatment.
authors.affiliation: Department of Conservative Dentistry, Periodontology and Preventive Dentistry, RWTH Aachen University Hospital, Pauwelsstrasse 30, 52074 Aachen, Germany; AALZ Aachen Dental Laser Center, Center for Biomedical Technology, RWTH Aachen Campus, Pauwelsstrasse 17, 52074 Aachen, Germany.
authors.forename: Rene
authors.initials: R
authors.lastname: Franzen
authors.affiliation: AALZ Aachen Dental Laser Center, Center for Biomedical Technology, RWTH Aachen Campus, Pauwelsstrasse 17, 52074 Aachen, Germany.
authors.forename: Nasrin
authors.initials: N
authors.lastname: Kianimanesh
authors.affiliation: Medical Material Science, RWTH Aachen University Hospital, Pauwelsstrasse 30, 52074 Aachen, Germany.
authors.forename: Rudolf
authors.initials: R
authors.lastname: Marx
authors.affiliation: AALZ Aachen Dental Laser Center, Center for Biomedical Technology, RWTH Aachen Campus, Pauwelsstrasse 17, 52074 Aachen, Germany.
authors.forename: Asma
authors.initials: A
authors.lastname: Ahmed
authors.affiliation: Department of Conservative Dentistry, Periodontology and Preventive Dentistry, RWTH Aachen University Hospital, Pauwelsstrasse 30, 52074 Aachen, Germany.
authors.forename: Norbert
authors.initials: N
authors.lastname: Gutknecht
mesh_terms: D003755:Dental High-Speed Technique / Q000009:adverse effects* / Q000295:instrumentation; D003804:Dentin / Q000293:injuries*; D006801:Humans; D053685:Laser Therapy / Q000009:adverse effects*; D053844:Lasers, Solid-State / Q000009:adverse effects* / Q000627:therapeutic use; D008963:Molar / Q000293:injuries; D013499:Surface Properties; D014082:Tooth Fractures / Q000175:diagnosis / Q000209:etiology*