title: Laser Doppler flowmetry: reproducibility, reliability, and diurnal blood flow variations.
abstract: The aim of this investigation was (1) to evaluate the reliability of laser Doppler flowmetry (LDF) taking into consideration the use of a silicone splint and the inclination of the probe towards the buccal surface of a human tooth and (2) to determine whether diurnal variations of pulpal blood flow can be registered by means of LDF. Forty-one splints were made by one and the same principal investigator for the registration of pulpal blood flow in vivo in a maxillary right central incisor. Thirty dentists, without experience in LDF recording, were then asked to drill a right-angled shaft in a pre-manufactured splint with a referral point at 2 mm from the enamel-cement border central on the buccal surface of the right central upper incisor. The remaining 11 splints were handled by the principal investigator. The shafts in the 30 splints were analysed using Cone Beam CT imaging of the axial and sagittal angles and compared these to the 11 shafts prepared by the trained principal investigator. LDF was recorded for 90 s in each splint and statistically analysed. LDF values without the use of a splint were statistically significantly different (p < 0.05) and the variance was greater, indicating the superiority of splint use. Significant diurnal variations on LDF values were observed, indicating that special attention should be paid to registration during the day, especially when multiple measurements are to be compared.
authors.affiliation: Department of Restorative Dentistry and Endodontology, Ghent Dental Laser Centre, Ghent Dental Photonics Research Cluster, Dental School, Ghent University Hospital, Ghent University, Ghent, Belgium. herman.roeykens@ugent.be.|Department of Restorative Dentistry and Endodontology, Dental School, Ghent University, De Pintelaan 185/P8, B-9000, Ghent, Belgium. herman.roeykens@ugent.be.
authors.forename: Herman J J
authors.initials: HJ
authors.lastname: Roeykens
authors.affiliation: Biostatistics Unit, Department of Public Health, Ghent University, Ghent, Belgium.
authors.forename: Ellen
authors.initials: E
authors.lastname: Deschepper
authors.affiliation: Department of Restorative Dentistry and Endodontology, Ghent Dental Laser Centre, Ghent Dental Photonics Research Cluster, Dental School, Ghent University Hospital, Ghent University, Ghent, Belgium.
authors.forename: Roeland J G
authors.initials: RJ
authors.lastname: De Moor
mesh_terms: D002940:Circadian Rhythm / Q000502:physiology*; D003782:Dental Pulp / Q000502:physiology*; D006801:Humans; D007180:Incisor; D017078:Laser-Doppler Flowmetry / Q000592:standards*; D012039:Regional Blood Flow / Q000502:physiology*; D015203:Reproducibility of Results
keywords: Circadian rhythm; Diurnal variations; Laser Doppler flowmetry; Pulpal blood flow; Vitality test