الفهرس 
INTRODUCTIONOnly 14 pages are availabe for public view
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Abstract
Dental caries continues to be a major problem in pediatric dentistry. The treatment of deep caries lesions approaching a healthy pulp presents a significant challenge to the practitioner.
Recent researches have revealed that carious dentin consists of two layers, the outer carious dentin is greatly softened by demineralization and its tubules are invaded by bacteria. It is insensitive, non-vital and non-remineralizable.
In contrast, the inner carious dentin contains no or few bacteria and is intermediately softened. It is sensitive, vital and remineralizable, and can be preserved, even when it was stained.
However, the extent to which carious dentin should be removed in order to achieve a mechanically and biologically successful restoration is still a matter of debate. In particular, no definite diagnostic tool is today available to clinically define the caries removal endpoint, enabling complete removal of infected tissue without over-extending cavity preparation.
In addition, the different techniques presently available for caries removal and cavity preparation produce residual dentin substrates (smear layer) of different natures and thus different receptiveness for adhesion.
A new device, the FACE light probe, together with the FACE filter goggles, form a tool which can be used to directly visualize the remaining bacterially infected dentin and to evaluate the success of caries excavation. Using the FACE light probe simply illuminates the cavity in much the same way as using a polymerization lamp. The metabolic process taking place in the bacteria leaves porphyrins as a metabolic product.
They present a clearly identifiable red fluorescence under violet light while healthy tooth substance can be clearly distinguished by its characteristic green fluorescence. The present in vitro study evaluated the effect of smear layer removal on residual caries detection using fluorescence-aided caries excavation light probe.
A total of thirty extracted or shed, non restored carious primary canines and molars, presumably involving dentin were used. Only soft dentin was removed stepwisely. Hard dentin was preserved, even when it was stained. The FACE light probe was used to check the cavity after excavation. The cavity was inspected through the filter goggles and only the orange-red fluorescence was considered carious while green fluorescence areas were considered free from caries.
All cavities were then acid etched with 37% orthophosphoric acid for 15 seconds, rinsed and air dried. Then they were re-illuminated by the FACE light probe with the same previous criteria of diagnosis. All the cavities were tested by the scanning electron microscope to determine surface characteristics of the floor after caries and smear layer removal.
Results of the present study revealed that there was a statistically significant difference in the presence of caries as detected by the three diagnostic methods. No statistically significant difference was observed between visual tactile examination and EM. While a statistically significant difference was observed between the gold standard and FACE, either before or after smear layer removal. Visual tactile examination compared to gold standard had zero sensitivity, 100% specificity and 83% negative predictive value.
FACE light probe (before/after) dark orange-red color compared to gold standard had 100% sensitivity, 100% specificity, 100% positive predictive value and 100% negative predictive value.
FACE light probe (before/after) green and light orange-red fluorescence compared to gold standard had 100% sensitivity, 100% specificity, 100% positive predictive value and 100% negative predictive value.