Two decades of computerized information technologies in dental radiography.
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Computer-Assisted Instruction↗
Biomedical subjects
Ann Wenzel
Publications and source records attributed to Ann Wenzel.
Diagnostic outcome of methods frequently used for caries validation. A comparison of clinical examination, radiography and histology following hemisectioning and serial tooth sectioning.
The aim of this study was to compare the caries diagnostic outcome of four methods frequently used as validation for dental caries. The diagnostic outcome of clinical examination (CL), radiography (RA), and histology after serial tooth sectioning (HI-serial) on 373 approximal and 158 occlusal surfaces was compared, and furthermore histology after hemi- (HI-hemi) and serial sectioning on another 113 approximal and 53 occlusal surfaces was compared. Two thresholds for each method (CL: (1) sound vs. all caries scores, and (2) non-cavitated vs. cavitated lesions; RA and HI: (1) sound vs. all caries scores, and (2) no dentine vs. dentine lesions) were evaluated. In general, large differences in diagnostic outcomes were observed with the various methods. At threshold 1, CL resulted in significantly more lesions than both RA and HI-serial on approximal surfaces, and than RA on occlusal surfaces. At threshold 2, no significant differences between CL, RA and HI-serial were found on approximal surfaces, but on occlusal surfaces significantly more lesions were diagnosed with RA and HI-serial than with CL. Significantly more occlusal lesions were found by HI-serial than by RA at both thresholds 1 and 2. On approximal surfaces, a similar result was found only at threshold 1. On approximal surfaces, significantly more lesions were diagnosed with HI-serial than with HI-hemi at both thresholds 1 and 2. On occlusal surfaces the same was found only at threshold 1. The intra-observer reproducibility was higher using HI-serial than using RA and CL.
Dental Caries↗
Influence of number of surfaces and observers on statistical power in a multiobserver ROC radiographic caries detection study.
The aim of the study was to evaluate the influence of the number of surfaces (N(SURF)) and the number of observers (N(OBS)) on the statistical power of a study comparing the diagnostic accuracies of radiographic systems used for approximal caries lesion detection. A data set consisting of 338 surfaces examined by 10 independent observers using four radiographic systems was available. The presence of a caries lesion was assessed from a 5-point confidence scale. The true lesion diagnosis was established by histological validation. ROC curve areas (A(z)s) were used to express the diagnostic accuracy of the observers with the radiographic systems. Assuming that the A(z)s were tested by a two-way analysis of variance, we performed a simulation study in order to evaluate how the power of this statistical analysis depended on N(SURF) and N(OBS). As a measure of the statistical power we used the standard error of the difference between the expected A(z)s of two systems. The simulations were made with N(SURF) in the range from 25 to 338 and N(OBS) from 2 to 10. The simulations showed that the power increased as a function of the total number of evaluations per system (N(SURF) x N(OBS)), but how this number was attained in relation to the number of surfaces and observers had only marginal influence on the power. Thus, from a statistical point of view it may be concluded, provided that data are analyzed by a two-way analysis of variance, that study designs for comparing the accuracy of several systems can be composed freely in relation to the number of surfaces and observers as long as the total number of evaluations per system are identical.
Analysis of Variance↗
Relationship between histological and radiographic caries lesion depth measured in images from four digital radiography systems.
The aim of this study was to compare the accuracy of approximal caries lesion depth measurements in radiographs from four digital systems. Two CCD-based sensors, Dixi (Planmeca) and Sidexis (Sirona), and two phosphor plate systems, Digora (Soredex) and DenOptix (Gendex), were used to record radiographs of 177 extracted human teeth. Sixty-four radiographically visible lesions were selected and measured by 4 observers in the digital radiographs and in digital photographs of histological sections of the teeth. The gold standard (true measure) was defined as the mean of the 4 observers' measurements on the histological sections. Two untrained observers underestimated general lesion depth in all the radiographic systems while each of 2 trained observers underestimated the depth in one of the systems. Analysis of variance revealed that Digora images resulted overall in the smallest underestimation, followed by Dixi, DenOptix and Sidexis. The differences between Digora and Sidexis and between Dixi and Sidexis were statistically significant (p < 0.05). Analysis of variance using the regression coefficient as the test variable demonstrated that the coefficients differed between DenOptix and the remaining systems (p < 0.05) while there were no significant differences between these (p > 0.05). It can be concluded that radiographs obtained with the Dixi and Digora systems were more accurate than Sidexis and DenOptix images for measurement of caries lesion depth. Still, a high probability exists that the individual lesion measurement is either overestimated or underestimated compared to the true lesion depth.
Analysis of Variance↗
Bone healing following immediate versus delayed placement of titanium implants into extraction sockets: a prospective clinical study.
PURPOSE: The aim of this study was to compare bone healing and crestal bone changes following immediate (Im) versus delayed (De) placement of titanium dental implants with acid-etched surfaces (Osseotite) in extraction sockets. MATERIALS AND METHODS: Forty-six patients were randomly allocated to the Im or De group (n = 23 per group) and received 1 implant at the incisor, canine, or premolar region of the maxilla or the mandible. The implants were placed an average of 10 days following tooth extraction in the Im group and approximately 3 months after extraction in the De group. The widths (parallel and perpendicular to the implant) and the depth of marginal bone defects around the implants were measured clinically just after placement and 3 months later at the abutment surgery. The crestal bone changes mesially and distally to the implants were evaluated radiographically by linear measurements. RESULTS: The survival rates were 91% in the Im group and 96% in the De group. In the Im group, the mean reductions in parallel width, perpendicular width, and depth of the largest defect of each implant amounted to 48% (from 4.4 to 2.3 mm), 59% (from 2.2 to 0.9 mm), and 48% (from 6.9 to 3.6 mm), respectively. The corresponding mean reductions in the De group amounted to 39% (from 3.1 to 1.9 mm), 77% (from 1.3 to 0.3 mm), and 34% (from 4.4 to 2.9 mm). The reduction over time was statistically significant in both groups (P < .04). For both groups, a higher degree of bone healing was achieved in the infrabony defects (> 60% for depth) than in dehiscence-type defects (approximately 25%). Furthermore, 70% of the 3-wall infrabony defects with a parallel width of up to 5 mm, a depth of maximum 4 mm, and a perpendicular width of maximum 2 mm had a capacity of spontaneous healing within a period of 3 months. DISCUSSION AND CONCLUSION: New bone formation occurs in infrabony defects associated with immediately placed implants in extraction sockets.
Adult↗
Interproximal papilla levels following early versus delayed placement of single-tooth implants: a controlled clinical trial.
PURPOSE: The aim of this study was to evaluate interproximal papillae and clinical crown height following the placement of single-tooth implants according to early and delayed protocols. MATERIALS AND METHODS: Forty-five patients were randomly allocated to either the "early" group or the "delayed" group. They were treated with a single-tooth acid-etched Osseotite implant in the maxillary or mandibular anterior or premolar region an average of 10 days (in the case of early placement) or 3 months (in the case of delayed placement) following tooth extraction. Interproximal papilla dimensions and clinical crown height were evaluated using a score index in 39 patients who attended a follow-up visit 16 to 18 months after prosthesis delivery. The patients were evaluated in photographs taken 1 week after crown placement (baseline) and approximately 1.5 years after crown placement (follow-up). RESULTS: It was demonstrated by logistic regression the risk of presenting no papilla or a negative papilla was 7 times greater at baseline for delayed cases than for early cases (33% versus 8%). However, the soft tissue fill in the proximal spaces improved significantly from baseline to the 1.5-year follow-up in both groups, with no significant difference between the groups found at follow-up. The papilla height almost 2 years after implant placement was inversely correlated with patient age. The clinical crown height was acceptable in significantly more cases in the early group than in the delayed group at follow-up. Half of the crowns in the delayed group exhibited an inappropriate height; of these, almost two thirds were assessed to be too short. DISCUSSION AND CONCLUSION: Early placement of single-tooth implants may be preferable to delayed implant placement technique in terms of early generation of interproximal papillae and the achievement of an appropriate clinical crown height, but no difference in papilla dimensions was seen at 1.5 years after seating of the implant crown.
Adult↗