An in vitro comparison of quantitative percussion diagnostics with a standard technique for determining the presence of cracks in natural teeth

Validity of quantitative values of quantitative light-induced fluorescent (QLF) device for pulp diagnosis of teeth with cracks

INTRODUCTION

The Quantitative Light-Induced Fluorescence (QLF) device provides both the visual information of crack lines on tooth surfaces and quantitative values for fluorescence reactions. The aim of this study was to evaluate the correlation and assess the usefulness of QLF quantitative values in pulp diagnosis of teeth with cracks.

METHODS

Pulp diagnosis was performed on 76 teeth with cracks according to the American Association of Endodontics's guidelines, and their QLF images were captured. The crack lines of the QLF images were quantitatively analyzed using the QLF software CrazeLineWizard01. QLF quantitative values (ΔF: fluorescence loss unit, ΔFmax: maximum of fluorescence loss unit, ΔR: red fluorescence gain unit, ΔRmax: maximum of red fluorescence gain unit) according to the pulp diagnosis of teeth with cracks were analyzed using one-way ANOVA. Multinomial logistic regression analysis was conducted to calculate the prediction of pulp diagnosis on QLF quantitative values. The correlation between the predicted pulp diagnosis and the clinical pulp diagnosis was compared using Pearson's correlation coefficient.

RESULTS

ΔF and ΔF max decreased with the progression of pulp disease in cracked teeth, while ΔR and ΔR max increased. Significant differences were found between irreversible pulpitis and pulp necrosis (p < 0.05). Pearson correlation coefficients between predicted and clinical pulp diagnosis based on multinomial logistic regression analysis of QLF quantitative values ranged from 0.699 to 0.806. The accuracy of prediction​​was up to 82.1 % for reversible pulpitis, 73.1 % for irreversible pulpitis, and approximately 80.0 % for pulp necrosis.

CONCLUSIONS

The quantitative values from the QLF device demonstrate its potential for predicting the severity of pulp disease caused by tooth cracks.

CLINICAL SIGNIFICANCE

The quantitative values of QLF images acquired with a QLF device, which provide visual information on crack lines of teeth through fluorescence reactions on the tooth surface, showed a significant correlation and predictive value for pulp diagnosis as pulp disease progressed in teeth with cracks.

Finite element modeling of an intact and cracked mandibular second molar under quantitative percussion diagnostics loading

STATEMENT OF PROBLEM

Quantitative percussion diagnostics (QPD) has been devised to nondestructively evaluate the mechanical integrity of human teeth and implants, the mechanical integrity of the underlying bone, and the presence of cracks, but the mechanism is not clearly understood.

PURPOSE

The purpose of this study is to better understand the dynamic behavior of a tooth under conditions consistent with QPD by focusing on physiologically accurate 3D finite element models of a human mandibular second molar with surrounding tissues.

MATERIAL AND METHODS

Finite element analysis (FEA) was used to study the force response of dental structures measured by the sensor in a QPD handpiece. A defect-free (intact) and a cracked tooth model containing a vertical crack involving enamel, dentin, periodontal ligament, bone, and the QPD percussion rod were used for this purpose. Different crack gap spaces were studied for comparison. The FEA model was validated with clinical QPD data for a second mandibular molar containing a vertical crack that subsequently had to be extracted. The location and size of the vertical crack was determined once the tooth was extracted.

RESULTS

The present FEA results exhibited features consistent with those of corresponding clinical data, thus verifying the model. An examination of the relative acceleration of the crack faces with respect to each other revealed that an oscillation between the crack surfaces results in secondary peaks in the QPD energy return response compared with that of an intact tooth.

CONCLUSIONS

The present FEA modeling can generate simulated QPD results that exhibit established distinguishing characteristics in clinical QPD data for intact and cracked second mandibular molars. The model results also give insight into how QPD detects the presence of cracks and show that the oscillation of crack surfaces can produce the multipeak QPD results for a cracked molar observed clinically.

An evaluation of quantitative percussion diagnostics for determining the probability of a microgap defect in restored and unrestored teeth: A prospective clinical study

STATEMENT OF PROBLEM

Current dental diagnostics are image based and cannot detect a structural microgap defect such as a crack in a tooth. Whether percussion diagnostics can effectively diagnose a microgap defect is unclear.

PURPOSE

The purpose of the present study was to determine from a large multicenter prospective clinical study whether quantitative percussion diagnostics (QPD) could detect structural damage in teeth and whether a probability of its presence could be provided.

MATERIAL AND METHODS

A nonrandomized prospective and multicenter clinical validation study with 224 participants was performed in 5 centers with 6 independent investigators. The study used QPD and the normal fit error to determine whether a microgap defect was present in a natural tooth. Teams 1 and 2 were blinded. Team 1 tested teeth scheduled for restoration with QPD, and Team 2 disassembled the teeth aided by a clinical microscope, transillumination, and a penetrant dye. Microgap defects were documented in written and video formats. Controls were participants without damaged teeth. The percussion response from each tooth was stored on a computer and analyzed. A total of 243 teeth were tested to provide approximately 95% power to test the performance goal of 70%, based on an assumed population overall agreement of 80%.

RESULTS

Regardless of the collection method, tooth geometry, restoration material used, or restoration type, the data on detecting a microgap defect in a tooth were accurate. The data also reflected good sensitivity and specificity consistent with previously published clinical studies. The combined study data showed an overall agreement of 87.5% with a 95% confidence interval (84.2 to 90.3), beyond the 70% predetermined performance goal. The combined study data determined whether it was possible to predict the probability of a microgap defect.

CONCLUSIONS

The results showed that the data on detecting microgap defects in a tooth site were consistently accurate and confirmed that QPD provided information to aid the clinician in treatment planning and early preventative treatment. QPD can also alert the clinician of probable diagnosed and undiagnosed structural problems via the use of a probability curve.

Diagnosis of cracked tooth: Clinical status and research progress

Cracked tooth is a common dental hard tissue disease.The involvement of cracks directly affects the selection of treatment and restoration of the affected teeth.It is helpful to choose more appropriate treatment options and evaluate the prognosis of the affected tooth accurately to determine the actual involvement of the crack.However, it is often difficult to accurately and quantitatively assess the scope of cracks at present.So it is necessary to find a real method of early quantitative and non-destructive crack detection.This article reviews the current clinical detection methods and research progress of cracked tooth in order to provide a reference for finding a clinical detection method for cracked tooth.

The Effectiveness of a Quantitative Light-induced Fluorescent Device for the Diagnosis of a Cracked Tooth: A Case Report

Diagnosing a cracked tooth is a challenge for dental clinicians. This report describes the use of a quantitative light-induced fluorescent (QLF) device that detects fluorescence reactions with visible light (405 nm) to visually identify microscopic tooth cracks during the diagnosis and treatment of cracked teeth that caused pulp disease. Fluorescence images of the occlusal surface, before and after removal of the restoration, and inside of the access cavity for root canal treatment were obtained using an intraoral capture-type QLF device (Q-ray penC; AIOBIO, Seoul, Korea). The device provided visual information such as enhanced magnification and fluorescent images to identify cracks on the exterior of the tooth, around restorations, and inside the cavity after removal of the restoration by a simple image capture process. The device was able to demonstrate the existence of the crack line and to predict the depth of cracks during treatment.The QLF device showed a potential benefit in the diagnosis and characterization, including the location and depth, of tooth cracks.

Ten-year retrospective study of the effectiveness of quantitative percussion diagnostics as an indicator of the level of structural pathology in teeth

STATEMENT OF PROBLEM

Conventional dental diagnostic aids are only partially effective in diagnosing structural defects such as cracks in teeth. A more predictable diagnostic for structural instability in the mouth is needed.

PURPOSE

The purpose of this clinical study with an increased population size was to evaluate the effectiveness of diagnosing structural instability by using the quantitative percussion diagnostics (QPD) system and to evaluate the influence of independent variables on the relationship between normal fit error (NFE) and observed structural instability found during the clinical disassembly of teeth.

MATERIAL AND METHODS

Twenty-two participants with 264 sites needing restoration were enrolled in an institutional review board-approved 10-year retrospective clinical study. Each site had been tested with the QPD system before being disassembled microscopically with video documentation, and the clinical disassembly results were recorded on a defect-assessment sheet. The NFE data were separately recorded from the preexisting records. The classification of structural pathology based on the disassembly observations for each of the 264 sites was conducted by the clinical researcher (C.G.S.) who was blinded to the NFE values.

RESULTS

The 264 sites from 22 patients were classified as 8 in the none group, 87 in the moderate group, and 169 in the severe group based on the disassembly findings. The NFE data for the sites were analyzed by using the predefined NFE cutoffs that were independently generated from the previous cumulative logistic regression and decision tree model. For the cumulative logistic regression, 235 out of 264 sites were correctly classified with an agreement of 0.89 (adjusted 95% CI: 0.83-0.95). The number of correctly classified sites for the decision tree model was 234, and the agreement was also 0.89 (adjusted 95% CI: 0.83-0.94). For both cumulative logistic regression and decision tree models, the overall misclassification rate was less than 20% for any restoration material or restoration type. Therefore, the overall performance of NFE classification was consistently good, regardless of restoration material or type. In addition, the sensitivity of the severe category was above 90% for any restoration material or type for the decision tree model.

CONCLUSIONS

The QPD system was found to be a reliable diagnostic aid for classifying structural damage in the categories of none, moderate, or severe based on clinical disassembly findings under the clinical microscope and NFE values. Furthermore, it was determined that restoration type and restoration design were not significant factors in correlating structural pathology with NFE.

Quantitative percussion diagnostics as an indicator of the level of the structural pathology of teeth: Retrospective follow-up investigation of high-risk sites that remained pathological after restorative treatment

STATEMENT OF PROBLEM

Structural damage may remain even after a tooth is restored. Conventional diagnostic aids do not quantify the severity of structural damage or allow the monitoring of structural changes after restoration.

PURPOSE

The purpose of this retrospective clinical study was to provide an in-depth analysis of 9 high-risk sites after restoration. The analysis followed structural defects found upon disassembly, restorative materials used, therapeutic procedures provided, current longevity, and long-term quantitative percussion diagnostics (QPD) to monitor results. The hypothesis was that QPD can be used to quantify positive and negative changes in structural stability.

MATERIAL AND METHODS

Sixty sites requiring restoration were part of an institutional review board-approved clinical study. Each participant was examined comprehensively, including QPD testing, at each follow-up. Long-term changes in normal fit error (NFE) values after restoration were evaluated according to a pathology rating system established in an earlier publication. Nine highly compromised sites were chosen for further analysis and monitored for an additional 6 years.

RESULTS

Of the 9 high-risk sites (NFE>0.04), 7 sites improved and 2 sites deteriorated. Potential causes for each trend were documented.

CONCLUSIONS

The data support the hypothesis that QPD can be used to monitor changes in structural stability after restoration. Knowledge of changes in advance of any symptoms allows further preventive or therapeutic intervention before serious structural damage can occur. Follow-up QPD indications of site improvement can also assure the clinician of the desired structural outcome.