In vivo study of the effectiveness of quantitative percussion diagnostics as an indicator of the level of structural pathology of teeth after restoration.

STATEMENT OF PROBLEM: Conventional diagnostic aids based upon imagery and patient symptoms do not indicate whether restorative treatments have eliminated structural pathology. PURPOSE: The purpose of this clinical study was to evaluate quantitative percussion diagnostics (QPD), a mechanics-based methodology that tests the structural integrity of teeth noninvasively. The study hypothesis was that QPD would provide knowledge of the structural instability of teeth after restorative work. MATERIAL AND METHODS: Eight participants with 60 sites needing restoration were enrolled in an IRB-approved clinical study. Each participant was examined comprehensively, including QPD testing. Each site was disassembled and microscopically video documented, and the results were recorded on a defect assessment sheet. A predictive model was developed for the pathology rating based on normalized fit error (NFE) values using data from the before treatment phase of the study published previously. Each restored site was then tested using QPD. The mean change in NFE values after restoration was evaluated by the pathology rating before treatment. The model was then used to predictively classify the rating after restoration based on the NFE values after treatment. The diagnostic potential of the rating was explored as a marker for risk of pathology after restoration. RESULTS: After restoration, 51 of the 60 sites fell below an NFE of 0.04, representing a greatly stabilized tooth site sample group. Several sites remained in the high-risk category and some increased in pathologic micromovement. Two models were used to determine severity with indicative cutoff points to group sites with similar values. CONCLUSIONS: The data support the hypothesis that QPD can indicate a revised level of structural instability of teeth after restoration.

In vivo study of the effectiveness of quantitative percussion diagnostics as an indicator of the level of the structural pathology of teeth.

STATEMENT OF PROBLEM: Conventional dental diagnostic aids based upon imagery and patient symptoms are at best only partially effective for the detection of fine structural defects such as cracks in teeth. PURPOSE: The purpose of this clinical study was to determine whether quantitative percussion diagnostics (QPD) provided knowledge of the structural instability of teeth before restorative work begins. QPD is a mechanics-based methodology that tests the structural integrity of teeth noninvasively. MATERIAL AND METHODS: Eight human participants with 60 sites needing restoration were enrolled in an institutional review board-approved clinical study. Comprehensive examinations were performed in each human participant, including QPD testing. Each site was disassembled and microscopically video documented, and the results were recorded on a defect assessment sheet. Each restored site was then tested using QPD. The normal fit error (NFE), which corresponds to the localized defect severity, was correlated with any pretreatment structural pathology. RESULTS: QPD agreed with clinical disassembly in 55 of 60 comparisons (92% agreement). Moreover, the method achieved 98% specificity and 100% sensitivity for detecting structural pathologies found later upon clinical disassembly. Overall, the NFE was found to be highly predictive of advanced structural pathology. CONCLUSIONS: The data from the present in vivo study support the hypothesis that QPD can provide the clinician with advance knowledge of the structural instability of teeth before restorative work begins.