IADR Abstract Archives

Spectral Transmission Through Dentine For Potential Dental Disinfection and Photobiomodulation

Objectives: Stimulation of natural wound healing processes by photobiomodulation and disinfection of contaminated dental lesions may be possible using light energy of specific wavelength. This study aims to investigate the penetration of near-UV, visible and near infrared light through dentine in order to assess its potential for therapeutic treatment of dental disease and trauma.

Methods: Caries-free wisdom teeth were set in epoxy-resin and sectioned through the pulp chamber by either cutting perpendicular to the crown, the buccal aspect or oblique sections. Specimens from each orientation were wet polished to 1, 2 or 3mm thickness (n=5; Silicon-carbide, P220 & P1200) to expose dentine on two opposing surfaces. The absolute irradiance of 9 ϕ5mm, epoxy encased LEDs (400-900nm) were measured using a calibrated fibre-based UV-Vis spectrometer (USB4000, Ocean Optics) through the dentine specimens and transmission percentage (LT) calculated. Statistically significant differences were identified by using multi-factorial analysis of variance and post-hoc Tukey tests (p=0.05).

Results: LT was dependent on dentine orientation, LED wavelength and dentine thickness. The general-linear model of independent variables revealed significant differences (p<0.001) which were wavelength (df=8;F=653.44) > thickness (df=2;F=278.32) > orientation (df=2;F=117.12). LT at each wavelength was significantly higher for crown or oblique sections compared with those from the buccal aspect (p<0.05). LT was significantly increased (p<0.05) at 605nm and 660nm and significantly decreased at shorter and longer wavelengths (Table 1).

Table 1: LT percentage through dentine specimens. Standard deviations are presented in parentheses and significant differences from one-way ANOVA and post-hoc Tukey tests within each thickness group is represented by superscripts.

Specimen/ λ	400nm	450nm	500nm	545nm	605nm	660nm	710nm	780nm	810nm
Crown 1mm	20.2 (8.2)^a	21 (7.3)^a	26.2 (7.5)^a	43.5 (4.5)^a	58.9 (4.2)^a	58.5 (3)^a	55 (2.8)^a	49.8 (5.6)^a	48 (5)^a
Oblique 1mm	16.9 (5.3)^a	15.5 (3.7)^b	23.1 (7.1)^a	34.9 (2.9)^b	42.2 (3.1)^b	48.4 (1.8)^b	42.7 (2.9)^b	40.2 (4)^b	38.2 (4.3)^b
Buccal 1mm	16.2 (5.5)^b	13.8 (3.7)^b	19.4 (4.4)^b	30.8 (2.5)^b	40.7 (4.1)^b	39.8 (1)^c	36.3 (3)^c	33.4 (3.9)^b	31 (2.6)^c

Crown 2mm	6.3 (5.9)^a	9.9 (4.2)^a	18 (3.5)^a	27.8 (2.2)^a	36 (1.8)^a	42.7 (1.3)^a	37 (0.8)^a	37.6 (1.5)^a	38 (1.6)^a
Oblique 2mm	4.4 (4.3)^b	7.1 (2.9)^b	12.4 (1.8)^b	21.8 (1.8)^b	25.6 (4.8)^b	33.3 (3.3)^b	29.1 (1.8)^b	27.4 (1.7)^b	28.3 (2.6)^b
Buccal 2mm	3.9 (12.8)^b	5.7 (5.1)^c	10 (5)^c	15 (5.6)^c	18.2 (6.2)^c	20.6 (4)^c	17.8 (5.3)^c	16.9 (5.5)^c	17.4 (5.8)^c

Crown 3mm	1.7 (5.9)^a	3.3 (2.5)^a	9.8 (2.9)^a	14.8 (3.6)^a	21.9 (3.2)^a	29 (3.2)^a	26.2 (2.5)^a	25.5 (2.1)^a	28.9 (2.6)^a
Oblique 3mm	1.3 (5)^a	2.7 (3.3)^b	6 (5.1)^b	10.8 (1.3)^b	8.3 (13.9)^b	17.7 (2)^b	15.5 (3.5)^b	16.1 (4.8)^b	16.6 (3.7)^b
Buccal 3mm	1 (20.6)^b	2.5 (8.6)^b	5.2 (7.5)^b	7.6 (7.1)^c	3 (32)^c	12.5 (5.9)^c	10.1 (4.7)^c	9.6 (6.2)^c	11.8 (4.5)^c

Conclusion: Of the wavelengths tested here, an optimal window of increased light penetration was observed between 600-700nm and was dependent upon orientation and thickness of dentine. The wavelengths tested may have therapeutic significance for the photobiomodulatory therapies of pulp tissue and disinfection of contaminated dental lesions.

Division: Pan European Region Meeting
Meeting: 2014 Pan European Region Meeting (Dubrovnik, Croatia)
Location: Dubrovnik, Croatia
Year: 2014
Final Presentation ID: 171
Abstract Category|Abstract Category(s): Scientific Groups

Authors

Hadis, Mohammed ( University of Birmingham, Birmingham, , England )

Cooper, Paul R. ( University of Birmingham, Birmingham, , England )

Milward, Mike ( University of Birmingham, Birmingham, , England )

Palin, Will ( University of Birmingham, Birmingham, , England )

SESSION INFORMATION

Poster Session
Pulp Biology and Regeneration II
09/11/2014