Linear and nonlinear analysis of dental pulp blood flow oscillations in ageing.
AIM
To investigate the effect of ageing on control mechanisms of pulpal microcirculation using wavelet analysis and to calculate linear and nonlinear parameters of blood flow oscillations, in a healthy general population.


METHODOLOGY
Pulpal blood flow (PBF) oscillations were recorded on right maxillary central incisors using laser Doppler Flowmeter (PeriFlux PF 5001, Perimed, Jarfalla, Sweden) on a group of 10 young participants (20-25 years) and a group of 10 older adults (60-70 years). In total, 20 recordings were obtained for at least 20 min (one recording on one tooth per subject). Using wavelet spectral analysis, the amplitude and power were calculated as a linear and Hurst exponent as a nonlinear parameter of PBF oscillations. Differences between the two groups were assessed with the independent Student t-test.


RESULTS
Mean PBF levels were significantly lower (P = 0.024) in older adults than in young participants. Relative amplitudes and powers corresponding to the myogenic (P = 0.046, P < 0.001, respectively) and neurogenic activity (P = 0.04, P = 0.01, respectively) were significantly higher, whereas values corresponding to the endothelial function (P = 0.04, P = 0.01, respectively) were significantly lower in older adults than in young participants. Hurst exponents of the total spectrum, myogenic and endothelial component (P < 0.001, P = 0.02, P < 0.001, respectively) of PBF oscillations were significantly lower in older adults in comparison to young participants.


CONCLUSIONS
At the level of pulpal microcirculation, ageing was associated with altered blood flow levels, the contribution of different control mechanisms to blood flow oscillations as well as the interaction of vascular smooth muscle and endothelium. Described changes of pulpal haemodynamics contribute to a better understanding of physiological behaviour and decreased adaptability of aged dental pulp to pathological stimuli.
['Dzeletovic|B|B|https://orcid.org/0000-0002-3486-5438', 'Stratimirovic|D J|DJ|', 'Stojic|D|D|', 'Djukic|L J|LJ|https://orcid.org/0000-0001-7033-4338']
D000368:Aged D000375:Aging D003782:Dental Pulp D006439:Hemodynamics D006801:Humans D017078:Laser-Doppler Flowmetry D012039:Regional Blood Flow D013548:Sweden
ageing wavelet analysis dental blood flow