Biomedical subjects

Aine M Lennon

Publications and source records attributed to Aine M Lennon.

3 recordsLinked to original sources

PubMed2004

Comparative fluorescence spectroscopy of root caries lesions.

In this study, the light-emission properties of carious and sound root surfaces were investigated under a wide range of excitation wavelengths. Human molar teeth with exposed root surfaces containing light- and dark-discolored root caries (n = 3 of each) were selected. Emission spectra were recorded from carious and corresponding sound root surface areas from each tooth by using a fluorescence spectrophotometer at excitation wavelengths from 360 nm up to 580 nm, in steps of 20 nm. The spectra were corrected for fluctuations in detector sensitivity and excitation light intensity, and normalized to peak intensity. Excitation spectra were recorded for selected emission wavelengths that showed maximum intensity. Light- and dark-discolored root surface caries showed distinct fluorescence emission bands between 600 and 700 nm that were not present in sound root surface areas. These bands were strongest for excitation wavelengths between 390 and 420 nm. The excitation spectra of root caries revealed maximum excitation at around 405 nm, which is equivalent to the Soret band of porphyrin compounds. The emission spectra of both types of root caries lesions were shifted towards longer wavelengths (red shift at half maximum) when compared to the spectra of corresponding sound root surfaces. The red shift for dark-discolored root caries was higher than for light-discolored lesions at all excitation wavelengths.

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PubMedDate not supplied

Efficiency of 4 caries excavation methods compared.

UNLABELLED: This in vitro study compared the efficiency (time taken to excavate and successfully remove bacterially infected dentin) of Fluorescence Aided Caries Excavation (FACE), caries detector dye (CD), chemomechanical excavation (CS) and conventional excavation (CE). Teeth with dentin caries were assigned to 4 groups (n= 25). Caries excavation was carried out by one operator. In the FACE group, the operating field was illuminated with violet light. The operator observed the teeth through a high-pass filter and removed orange-red fluorescing areas with a slow speed bur. In the CS group, Carisolv was applied to the cavity using CS hand instruments and allowed to act for 30 seconds before caries was removed. In the CD group, caries was removed using the Caries Detector and, in the CE group, conventional excavation was carried out using visual-tactile criteria. The excavation time was recorded. Undecalcified thin slices (8 microm) were prepared, stained with giemsa and examined using light microscopy. The excavation time (median) was significantly shorter for FACE (3 minutes, 3 seconds) compared to CS (5 minutes, 8 seconds, p=0.015), CD (5 minutes, 26 seconds, p=0.003) and CE (4 minutes, 2 seconds, p=0.025). Histology showed remaining bacteria in significantly fewer (5/25) FACE samples compared to CS (15/25 p=0.004) CD (12/25 p=0.037) but not significantly fewer than CE (11/25 p=0.069). IN CONCLUSION: the excavation result with FACE is equal to CE and superior to CD and CS but requires a significantly shorter excavation time.

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PubMedDate not supplied

Fluorescence-aided caries excavation (FACE) compared to conventional method.

A recent study showed that orange-red fluorescence in carious dentin could be used to detect residual caries (Lennon & others, 2002). This study compared the ability of a new fluorescence-aided caries excavation technique (FACE) with the conventional method. Forty extracted teeth with occlusal dentin caries were selected. The teeth were bisected longitudinally through the center of the lesion. Lesion depth and width were measured and the teeth were divided into two groups of 20, each with the same average lesion size. The tooth halves were reassembled and fixed by embedding the roots in acrylic resin. Access cavities were prepared using a high-speed handpiece and diamond fissure bur. In the FACE group, violet light (370-420 nm) was fed into the fiber optics of a slow-speed hand-piece, so that it illuminated the operating field. The cavity was observed through a 530-nm high-pass filter and orange-red fluorescing areas were removed. In the conventional group, a sharp probe was used to detect soft dentin, which was removed. One-half of each tooth was stained for bacteria using Ethidium Bromide and examined using Confocal Laser Scanning Microscopy (CLSM). Bacteria were present in significantly (p=0.037) fewer FACE samples (3) compared to conventional samples (9). It can be concluded that the new method is more effective than conventional caries excavation.

Dental Caries↗