Three-Dimensional Analysis of Efficacy of Chemo-mechanical vs. Mechanical Caries Removal

Methods: Fifteen deciduous molars were bisected through open carious cavities. The two halves of each tooth were scanned using a high quantitative XMT scanner at 30 µm resolution. Following the initial scan, dentinal caries were removed from each pair of the same tooth samples using an excavator and Carisolv^TM (MediTeam, Sweden)/Caries Detector Dye (Kuraray Medical Inc., Japan). Each tooth sample was then re-scanned. The three-dimensional XMT data sets were then cropped to the volume of the carious lesion. Histograms of the Linear Attenuation Coefficients (LAC - values related to the mineral concentration) were obtained for the volume of the caries lesions before and after caries removal. A ‘blind method' analysis was used whereby the assessor did not know which half of the lesions were removed by hand excavation/Caries Detector Dye/Carisolv^TM for each of the samples. The difference LAC histogram (‘before' minus ‘after') was used to highlight differences between the chemo-mechanical techniques compared to hand excavation and help assess the better, more effective caries removal method.

Results: Of the samples comparing hand excavation and Caries Detector Dye, 75% were judged incorrectly i.e. the samples could not be distinguished between the two techniques. Of the samples comparing hand excavation and Carisolv^TM, 82% were judged correctly. Assessment was based on removal of the lesion body and retention of sound and partially demineralised (affected) dentine corresponding to excavation using Carisolv^TM.

Conclusions: This preliminary study suggests that Caries Detector Dye does not help to remove the infected carious dentine only with respect to hand excavation. Carisolv^TM is a more effective caries removal method of the three excavation techniques.