Evaluating diagnostic tests

General dentists' use of diagnostic equipment and methods

An accurate diagnosis is essential for making treatment decisions in dentistry. However, little research is available as to which tests are done routinely and how commonly they are performed. The purpose of this study was to investigate diagnostic methods and equipment used by general dentists in private practice in Perth. The study involved a retrospective audit of 30 patient records from seven individual general dentists working in private practices in the Perth Metropolitan area. De-identification of patient records was done prior to the researchers' visit. Radiographs were the most commonly used diagnostic tool. Percussion was also commonly employed, followed by cold pulp testing and mobility. The most commonly used tests were radiographs, percussion, periodontal probing and visual examination. The frequency of these tests differed depending on whether the patient presented with or without pain, with percussion and cold tests used more frequently when the patient presented with pain.

Use of Diagnodent for diagnosis of non-cavitated occlusal dentin caries

The purpose of this study was to evaluate the use of a laser fluorescence device for detection of occlusal caries in permanent teeth. One hundred and ninety-nine non-cavitated teeth from 26 patients aged 10 to 13 years were selected. After dental prophylaxis, two previously calibrated dentists examined the teeth. Visual inspection, radiographic examination and laser measurements were performed under standardized conditions. The validation method was cavity preparation with a small cone-shaped diamond bur, when the two examiners agreed about the presence of dentin caries. It was found that the laser detection method produced high values of sensitivity (0.93) and specificity (0.75) and a moderate positive predictive value (0.63). The laser device showed the lowest value of likelihood ratio (3.68). Kappa coefficient showed good repeatability for all methods. Although the laser device had an acceptable performance, this equipment should be used as an adjunct method to visual inspection to avoid false positive results.

Palpation and pressure pain threshold: reliability and validity in patients with temporomandibular disorders

This study assessed the interexaminer reliability and validity of palpation (PA) and pressure pain threshold (PPT) of the temporomandibular joint (TMJ) and the masseter and temporalis muscles in patients with temporomandibular disorders (TMD) and asymptomatic controls. Eighty (80) subjects were distributed into two groups: Group 1 consisted of 40 TMD patients with muscular and joint pain selected by RDC/TMD Axis I; and Group 2 (control) with 40 asymptomatic individuals. Training and calibration of examiners was undertaken prior to testing. Mean reliability values were 0.64 and 0.78 (PPT), and 0.59 and 0.75 (PA), for patients and controls, respectively. Results showed statistically significant differences (p<0.001), for PA and PPT among TMD patients compared with the control. The results also showed acceptable specificity values (above 0.90), although sensitivity had low values. The tests had low diagnostic validity to discriminate between patients and controls, with low positive predictive values (PPV).

Assessment of the accuracy of visual examination, bite-wing radiographs and DIAGNOdent on the diagnosis of occlusal caries

AIM

This was to evaluate the accuracy of the different methods for diagnosing occlusal caries in vivo, and to compare their performance in primary and permanent teeth.

STUDY DESIGN

Permanent teeth (199) and primary molars (65) with macroscopically intact occlusal surface, with caries lesions without cavitation (white spot) or with a darkened sulcus were selected. The teeth were examined by the following methods: visual inspection, bite-wing radiographs and DIAGNOdent. The validation method employed for asserting the existence of carious lesion was cavity preparation.

RESULTS

When the total sample was taken into consideration, laser (DIAGNOdent) provided the highest accuracy (74.8%). Even when the total sample was stratified, the laser accuracy was still high for both primary (88.4%) and permanent molars (70.4%). Visual inspection also provided a high accuracy for primary teeth (83.9%). The chi-square test showed a statistically significant difference between permanent and primary teeth considering occlusal caries diagnosis (p=0.0001). The Kappa coefficient showed good inter-examiner reproducibility for all methods. McNemar test revealed that the degree of intra-examiner agreement for visual inspection was lower than for the other methods.

CONCLUSIONS

As visual inspection also showed a high degree of accuracy, the laser method should be used as a complementary method in doubtful cases. Diagnostic methods of occlusal caries, in general, are more efficient in deciduous than in permanent teeth.

Ability of laser fluorescence device associated with fluorescent dyes in detecting and quantifying early smooth surface caries lesions

A laser fluorescence (LF) device is a portable tool, but it does not measure minor mineral changes. Our in vitro study aim is to propose the association of an LF with two fluorescent dyes and to evaluate the performance in detecting and quantifying early demineralization. Artificial caries lesions are created in 40 primary canine teeth using a demineralizing solution (pH=4.8) for 12, 24, 48, and 96 h. LF measurements are performed with DIAGNOdent after demineralization in these samples and in 20 sound primary teeth. Measurements with LF with 0.2-mM tetrakis(N-methylpyridyl)porphyrin (LF TMPyP) and with 4-mM protoporphyrin IX (LF PPIX) are made. The amount of calcium loss is determined by atomic emission spectrometry. A correlation between LF and LF with dyes and mineral loss and receiver operating characteristics analysis are performed, as well as comparisons of sensitivity, specificity, and accuracy values. Significant correlation is obtained with LF TMPyP and mineral loss of lesions demineralized for 24, 48, and 96 h. Better performance is achieved with LF TMPyP for all parameters than with LF alone. LF PPIX does not present good results. In conclusion, LF TMPyP provides good performance in detecting and quantifying very early enamel caries lesions.

Restorative service patterns in Australia: amalgam, composite resin and glass ionomer restorations

AIM

To examine the provision of amalgam, composite resin and glass ionomer restorations, and to assess whether these main restorative services varied by patient, visit and oral health characteristics.

DESIGN

A cross-sectional survey incorporating a log of service items provided on a typical day.

SETTING

Australian private general practice.

METHODS

Data on services and patients were collected by a mailed survey from a random sample of dentists from each State/Territory in Australia in 1998-99 with a response rate of 71%.

MAIN OUTCOME MEASURES

Rates per visit of amalgam, composite resin and glass ionomer restorations among dentate adults who had received a restoration.

RESULTS

Analysis showed older patients had lower amalgam rates but higher glass ionomer rates, composite resin rates were lower at emergency visits, capital city patients had higher amalgam rates but lower composite resin rates, patients with decayed teeth had higher amalgam and composite resin rates, and use of restorative materials varied by clinical problem.

CONCLUSIONS

Despite widespread use of alternative materials, amalgam rates remained high in circumstances such as replacement restorations and restorations involving more than one surface. Other restorative materials also had specific applications. Both amalgam and composite resins were provided at higher rates to patients with active caries but composite resins were also used at higher rates for aesthetic problems. Glass ionomer restorations were used at higher rates for initial and one-surface restorations, and for conditions such as root caries and dentinal sensitivity.

The diagnostic accuracy of microbiologic root canal sampling and the influence of antimicrobial dressings

The routine approach to endodontic treatment of teeth with apical periodontitis often involves an interappointment dressing with calcium hydroxide. However, investigations have demonstrated a negative influence of calcium hydroxide on the accuracy of microbiological root canal sampling (MRS). The aim of the present study was to investigate whether the use of a fluid dressing like 5% iodine potassium iodide (IPI) would increase the accuracy of MRS. Following instrumentation of 50 teeth with radiographically verified apical periodontitis the root canals received IPI as an intracanal dressing. One week after closure canals were sampled, "test sample" (TS), and then left filled with sampling fluid and temporarily scaled. Seven days later a "gold standard" (GS) sample was obtained. Bacteria were recovered in 22 teeth (44%) in TS as well as in GS. Fifteen teeth (30%) were positive for growth in both samples. Using the detection level "very sparse growth" of microbes the sensitivity and specificity of MRS reached 68% and 75%, respectively. In an earlier study, following the same experimental protocol, but with calcium hydroxide as intracanal dressing, the corresponding values were 33% and 81%. In 25% of these cases bacteria persisted in the canals. As compared to calcium hydroxide, the use of IPI resulted in improved test accuracy, but loss of antibacterial capacity. Conclusively, intracanal dressings seem to vary in their influence on the microbiologic test performance as well as in their antibacterial efficacy. In a clinical situation the choice of interappointment dressing should include consideration of these potentially conflicting properties.

Determination of Class II and Class III skeletal patterns: receiver operating characteristic (ROC) analysis on various cephalometric measurements

Receiver operating characteristic analysis is an excellent method for evaluating and comparing the performance of diagnostic tests. The purpose of this study was to use the receiver operating characteristic analysis to evaluate the diagnostic ability of several cephalometric measurements in determining the presence of Class II and Class III skeletal patterns. Receiver operating characteristic analysis was performed on 976 cases. Fifteen cephalometric measurements were evaluated. A computer software program ROC ANALYZER was used to tabulate the areas under the curves and to perform the statistical comparison between the curves. The results of this study indicated that the Anteroposterior Dysplasia Indicator had the best diagnostic ability in identifying cases with Class II and Class III skeletal patterns. WITS Appraisal and Overjet were highly effective in diagnosing cases with Class II skeletal pattern. WITS Appraisal, Convexity, AB Plane Angle and Overjet also performed well in diagnosing cases with Class III skeletal pattern.

Semiautomated procedures for evaluation of carbohydrate-deficient transferrin in the diagnosis of alcohol abuse

Carbohydrate-deficient transferrin (CDT) may now be the most valuable biological marker for diagnosis of alcohol abuse. We compared the diagnostic performance of two new CDT tests, Axis %CDT turbidimetric immunoassay (TIA) and Axis %CDT HPLC, against Specialty Laboratories’ isoelectric focusing/immunoblotting/laser densitometry (IEF/IB/LD). Both Axis tests include one-half the concentration of trisialotransferrin isoforms in their CDT quantitation schemes. Considering an alcohol abuse prevalence of 7%, Axis %CDT TIA shows a sensitivity of 87% at 98% specificity and a positive predictive value (PPV) of 0.75; %CDT HPLC shows a sensitivity of 87% at 100% specificity for a PPV of 1, and the IEF/IB/LD shows 81% sensitivity at 94% specificity for a PPV of 0.5. All three CDT tests show the same negative predictive value (0.98). Both Axis procedures perform better than IEF/IB/LD in the diagnosis of alcohol abuse; %CDT TIA is available in several semiautomated, cost-effective formats.

Principles of evaluation of the diagnostic value of subgingival bacteria

This paper describes steps in the process of evaluating subgingival bacteria assays for the diagnosis of periodontal disease. The first step examines the infectious etiology of periodontal disease in pointing to specific oral bacteria as periodontal pathogens. Second is characterization of the laboratory test to detect and quantitate these pathogens as to sensitivity, specificity, and positive and negative predictive value. Third is the role of the laboratory test in the diagnosis of the different forms of periodontal disease which is related to the current clinical rather than microbiological definition of these diseases. The fourth and most important step is an analysis of the significance of subgingival bacterial tests in clinical decision-making.

Detection of neutral protease (Periocheck) and BANA hydrolase (Perioscan) compared with traditional clinical methods of diagnosis and monitoring of chronic inflammatory periodontal disease

Perioscan requires a plaque sample to detect the presence of enzymes capable of degrading N-benzoyl-DL-arginine-2-naphthylamide (BANA) from relatively few anaerobic periodontal pathogens. Periocheck assays the presence of neutral proteases in crevicular fluid. The aim of this study was to compare these test kits with traditional clinical methods of detecting periodontal disease and to monitor the ability of the kits to reflect the response to initial therapy. 19 patients with moderately severe chronic periodontitis were seen before and after a course of oral hygiene and root instrumentation consisting of 4 appointments. Clinical measurements and test assays were collected at 5 diseased sites and 2 healthy sites in each subject. Complete data from 125 sites were available for statistical analysis. At baseline Periocheck had a sensitivity of 88% and a specificity of 61% whereas Perioscan had a sensitivity of 99% and a specificity of 55%, when related to the clinical diagnosis. A composite clinical assessment, based on improvement or deterioration of one whole unit change of the subjective clinical indices and 2 mm changes or greater in probing depth or probing attachment level, revealed 75 sites which improved following treatment, whereas 45 sites did not change and 5 sites deteriorated. The probability that the tests agreed with the clinical outcome after treatment, was calculated as 50.4% for Periocheck and 52% for Perioscan. The diagnostic kits did not reliably reflect the clinical assessment of periodontal disease in the cross sectional study, or the outcome following treatment.

The impact of recent changes in the epidemiology of dental caries on guidelines for the use of dental sealants

This paper reviews recent changes in the epidemiology of dental caries and assesses their potential impact on the diagnosis and management of the disease and the planning and operation of sealant programs. These changes, such as the decline in caries and slowing of the rate of progression of the disease, have important implications for diagnosing and treating incipient lesions, predicting caries risk, and conducting effective disease preventive programs. Traditional paradigms for restoring carious lesions are being replaced by newer strategies that emphasize disease prevention and conservation of tooth structure. The search continues for the identification of practical models for predicting caries risk at the individual level. This paper describes a method useful for targeting resources in sealant placement programs by enabling one to determine the relative effectiveness of sealing alternative tooth surfaces in the oral cavity. One guide serves as a widely adopted manual for those who use or intend to use dental sealants in caries prevention programs. This paper provides a brief review of that document, "Preventing Pit and Fissure Caries: A Guide to Sealant Use," as well as guidelines for sealant utilization provided by the American Dental Association, and information regarding dental sealant programs under Medicaid. The final portion of the paper provides a synthesis of the epidemiology reviewed and summarizes the implications of findings for sealant programs.

When will excellent radiographic images be available to the general dental office?

Dental radiography is a highly regarded diagnostic practice. More than 25% of all radiographs are taken for dental purposes, so their improvement will benefit many patients. Although recent advances in materials and processing have contributed to incremental improvements in film-based diagnoses, computer-based enhancement of digitized conventional radiographic images is likely to yield more significant benefits. However, until cost-effective digitizing systems have been developed for the general dental office, the benefits derived from precise radiographic diagnoses and associated improvements in the standards of care will continue to elude both dentist and public.