Contemporary adhesive restorative dentistry--an update on materials.
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Composite Resins↗
Biomedical subjects
E R Hewlett
Publications and source records attributed to E R Hewlett.
Relationships between clinician variability and radiographic guidelines.
This study evaluated the replicability of clinical measurements under careful calibration of multiple dentists and how the replicability can relate to their use as selection criteria in guidelines for prescribing dental radiographs. For 48 consenting patients, three dentists clinically examined each patient and recorded the presence of all clinical findings using standardized selection criteria. The examinations were performed independently of each other, but with periodic conferences of the dentists to clarify general measurement criteria. The degree of agreement among the dentists is described by the interrater agreement kappa for several standard clinical indications such as rating of caries, periodontal disease, and tooth mobility. Almost perfect agreement was obtained for tooth status, restoration size, and restoration material. Moderate agreement resulted for measures of caries, defective restoration presence, and gingival recession presence. Only fair agreement was obtained for other periodontal disease measures. The relationship between extent of agreement and guidelines' results was examined for the FDA Guidelines. The differences among the dentists' clinical measurements resulted in considerable differences among the radiographs that were selected by the FDA Guidelines' criteria. Even so, the missed disease rates for 490 patients in a larger study of the FDA Guidelines' efficacy were very low and did not vary greatly among the three dentists. We conclude that guidelines' criteria can be quite robust to variation from dentists' clinical measurement differences, as seen from the FDA Guidelines applied under the idealized setting where the dentists are periodically recalibrated through group discussions of the clinical measurements' definitions and interpretations.
Adolescent↗
Influence of occlusal force and mandibular position on tooth contacts in lateral excursive movements.
The diagnosis and treatment of occlusal disharmonies requires an understanding of the variables that affect occluding tooth contacts. Quantitative recordings of tooth contacts and near tooth contacts are necessary for detailed analysis of occlusion. In this study, different thicknesses of registration strips were used to assess the influence of occlusal force and mandibular position on tooth contacts and clearance. This assessment was made for nonworking side molars and working side premolars. There was a significant decrease in clearance with increased occlusal force on both the nonworking and the working sides. A significant increase of clearance was noted as the mandible moved to the most lateral position on the nonworking side. These results indicate that the variables of occlusal force and mandibular position represent potential sources of disparity in the recording of tooth contacts. These variables should be considered when occlusal examination procedures are conducted.
Adult↗
Efficacy of FDA guidelines for prescribing radiographs to detect dental and intraosseous conditions.
OBJECTIVES: This study compared the FDA guidelines for ordering dental radiographs to a conventional full-mouth examination for the detection of intraosseous disease and conditions affecting teeth other than caries. STUDY DESIGN: We examined 490 patients and selected posterior bite-wing and periapical views as indicated by the patient's signs or symptoms. We compared the radiographic findings with the use of this selected set of radiographs to those from a full-mouth set of radiographs to determine the rates of missed disease when the FDA guidelines were used. RESULTS: The most commonly missed intraosseous findings were osteosclerosis, unerupted teeth, periapical radiolucencies, and primary root tips. Periapical radiolucencies that were most probably periapical cemental dysplasia were missed in six patients. The most commonly missed dental findings were resorbed roots and pulp stones. Three instances of dens in dente were missed. CONCLUSIONS: When we used the FDA guidelines, the number of missed intraosseous and dental conditions was small and most likely inconsequential given the range of variability in dental diagnosis and treatment.
Adolescent↗
Efficacy of the FDA selection criteria for radiographic assessment of the periodontium.
The diagnosis of periodontitis is generally made on the basis of a clinical examination supported by radiographic evidence of bone loss. Recent guidelines promulgated by the US Food and Drug Administration recommend that periapical radiographs be ordered on the basis of clinical signs and symptoms indicating the probable presence of disease. This study evaluated the effectiveness of the FDA Guidelines for ordering radiographs for new adult dental patients as related to assessment of the periodontal condition of the patient. We examined 490 patients and determined the periapicals needed to supplement the posterior bitewings based upon the patient's clinical findings. We measured the reduction in the number of radiographs ordered as well as the extent of missed alveolar and furcation bone loss resulting from the use of the selected set of radiographs compared with a complete set. Four hundred thirty-three subjects had at least one clinical sign of periodontitis present in their mouths, and 264 demonstrated radiographic evidence of alveolar bone loss. Of the 460 subjects on whom periodontal probing was conducted, two-thirds demonstrated periodontal probing depths in excess of 3 mm; almost half showed evidence of bleeding upon probing. Individuals with clinical signs of periodontitis had, on average, 10 periapicals ordered--more than twice the number as those with no sign of periodontitis. Of the 2,415 teeth with radiographic findings of proximal or furcal bone loss, 152 sites of bone loss (6%) were missed when the selected set of films plus the posterior bitewings was used.
Adolescent↗
Clinical and historical predictors of dental caries on radiographs.
This report evaluates the efficacy of the clinical predictors of caries proposed in the USA FDA guidelines for prescribing dental radiographs. The clinical findings that best associate with the presence of any caries where a history of pain, a defective restoration, unusual calcification, and an abutment tooth for a fixed or removable prosthesis. There is a group of measures of periodontal disease that were also weakly associated with the presence of caries. The best predictors of caries extending into the dentin were the presence of clinically defective restorations, a history of pain, and signs of periodontal disease. Proximal lesions are likely to appear on teeth with defective restorations, unusual calcification or large or deep restorations. The best predictors of radiographic root caries are periodontal findings such as furcation involvement, increased mobility, a history of periodontal therapy and gingival recession. While the specificities for these findings were generally high, the sensitivities and positive predictive values were usually under 50%, and often much lower. Thus these clinical findings cannot successfully be used as exclusive criteria for ordering radiographs for caries detection. Because caries is found fairly frequently, and because we are unable to identify tooth-specific criteria with clinically useful sensitivity and specificity values, these data support the FDA panel recommendation of bitewing examinations for all new patients and at periodic intervals for recall patients.
Confidence Intervals↗
Assessing the FDA guidelines for ordering dental radiographs.
In 1988, the U.S. Food and Drug Administration issued guidelines to help dentists reduce the amount of X-ray exposure to patients without reducing the quality of care. This study assesses the efficacy of those guidelines. The authors examined 490 patients and ordered radiographs as indicated by the FDA guidelines. Using the guidelines, they ordered a mean of 9.7 radiographs out of a 17-film series, a reduction of 43 percent compared with a full-mouth series. The authors conclude that dentists can reduce a patient's exposure to X-rays by using these guidelines with a low level of missed radiographic findings, most of which would have no effect on the patient's treatment.
Adolescent↗
Efficacy of FDA guidelines for ordering radiographs for caries detection.
This study evaluated the effect on caries diagnosis of using the Food and Drug Administration (FDA) guidelines for ordering radiographs on a sample of new adult patients seeking general dental care at a dental school clinic. These guidelines recommend posterior bitewing views accompanied by supplemental periapical views as indicated by the patient's clinical signs or symptoms. We compared the findings from the use of this protocol to those from a full-mouth set of radiographs made on the same new patient. We examined 490 patients and ordered periapical radiographs in accordance with the FDA guidelines, namely, when there was some clinical sign or symptom suggesting the need for radiographs. A full-mouth set of radiographs was obtained, and both the full and selected sets were evaluated separately. We found that 95% of our patients had one or more carious lesions, with an average of 5.7 carious teeth per patient. Of the 2808 carious teeth detected in the study, 1949 (69%) were found radiographically and 1564 (56%) were found clinically. Indeed, 1244 (44%) of the carious teeth were detected only by radiographic examination. Use of the FDA guidelines resulted in a 43% reduction in the number of radiographs ordered. Reduction in the number of images made on patients resulted in failure to detect 93 lesions (3.3%) located on 88 teeth in 11.4% of the study patients. Most of the missed lesions (2.9%) were radiographically confined to the enamel of anterior maxillary teeth. Only 36 of the missed lesions (1.6% of all radiographic lesions) extended into the dentin. We believe that this number is very small and most likely inconsequential compared with the considerable diversity among dentists regarding radiographic detection of caries, as well as the diversity of opinion regarding the indications for restorative treatment.
Adolescent↗
Evaluation of three occlusal examination methods used to record tooth contacts in lateral excursive movements.
Accurate and repeatable methods for recording tooth contacts are required for the clinical management of problems related to occlusion. A thorough understanding of the materials and procedures used in these methods is important to achieve desirable results in the treatment of such problems. This study compared three occlusal examination methods to determine the influence of materials and procedures on the number of tooth contacts recorded. Tooth contacts were analyzed at two lateral mandibular positions with each method. It was found that the method that uses black silicone recorded the highest number of tooth contacts. Thus the most frequent type of occlusal pattern observed was full-balanced occlusion. This study suggested that the disparities of results reported in literature on occlusal contact patterns could be the result of the different materials and methods used for occlusal registration.
Adult↗
Radiographic secondary caries prevalence in teeth with clinically defective restorations.
Decisions to replace existing restorations are often based on clinical findings of margin discrepancies and other restoration defects. Previous studies have suggested that such findings do not correlate well with the actual presence of secondary caries, and that treatment should be deferred until caries is clinically or radiographically evident. The purpose of this study was to assess the frequency with which clinically defective restorations are associated with radiographic secondary caries. As part of a study to assess the efficacy of guidelines for the ordering of dental radiographs, 6285 restored teeth in 490 subjects were examined clinically and radiographically by three calibrated investigators. Specific criteria were used to determine whether restorations were intact or defective. Of the total, 822 teeth (13%) were judged to have clinically defective restorations. Of these, 113 teeth (14%) had radiographic secondary caries. Of the 5463 teeth with intact restorations, 5% had radiographic secondary caries. We found that the likelihood of radiographic secondary caries was nearly three-fold higher for defective restorations than for intact restorations. The large percentage (86%) of defective restorations with no radiographic secondary caries suggests, however, that replacement of all defective restorations due to risk of secondary caries may constitute overtreatment. The use of defective restoration status and presence of radiographic secondary caries as a combined criterion for replacement may potentially reduce such overtreatment. The prevalence of secondary caries under defective restorations should be determined clinically so that the usefulness of combining the criteria of defective restoration with those of radiographic secondary caries can be evaluated.
Analysis of Variance↗
Marginal discrepancy as related to margin design in porcelain-fused-to-Dicor restorations.
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Ceramics↗
Accuracy testing of three-dimensional digitizing systems.
An accuracy test designed as a standard for digital occlusal wear measurement devices was applied to such a device designed by the authors. The test was used for quantitative determination of measurement error for a given angle of tangential contact with the inclined planes of the surface being measured. Using known dimensions of the digitizer contact tip and of a precision steel sphere, we determined trigonometrically the error in the Z-axis measurement due to the slope of any point on the surface of the sphere. These values were used for a point-by-point correction of data obtained from actual digitization of the sphere. The corrected values would equal zero if no mechanical source of error existed. These values, then, quantitatively indicated the accuracy (in microns) of the device as a function of the slope of the measurement point. The results indicated a linear relationship between surface slope angle and measurement error for the device tested.
Dental Occlusion↗
Glass ionomer bond strength and treatment of dentin with polyacrylic acid.
This investigation compared the effect of smear layer removal using various treatments with polyacrylic acid on the shear bond strength of glass ionomer restorative materials to dentin. Three brands of glass ionomer were applied to prepared dentin surfaces of extracted human molars, after one of four treatments with polyacrylic acid. Samples using dentin surfaces with the smear layer left intact served as controls. Comparison of mean shear bond strength values for all possible combinations of restorative material and polyacrylic acid treatment indicated that samples produced using 25% polyacrylic acid had lower (p less than 0.05) values in some instances. No other significant differences were found when test values were compared with each other or with control values. The authors concluded that removal of the smear layer does not enhance the dentin-glass ionomer restorative bond strength, as has been suggested by other investigators. Scanning electron photomicrographs indicate that treatment with higher concentrations of polyacrylic acid produces higher degrees of dentinal tubular orifice patency.
Acrylic Resins↗
Comparison of casting ability of castable ceramic and type III gold.
This study compared the property of castability of a castable ceramic to an American Dental Association-certified type II casting alloy. A wax pattern was made with a manifold-type structure from which monofilament lines projected approximately 5 to 6 mm. The diameter of the nylon lines ranged from 132 micron to 1270 micron. Each pattern was invested and cast according to the manufacturer's specifications. Each casting was divested and measured for length of casting of the monofilament on a measuring microscope. The castable ceramic and type II gold cast completely at diameters of 1270 micron, and 724 micron, but only type II gold cast completely at the 152 micron and 132 micron diameters.
Ceramics↗
Visual and instrumental colorimetric assessments of small color differences on translucent dental porcelain.
The CIELAB colorimetric system was used for the study of the relationship between measured color difference values and human observer responses. This study verified that a specific, visually meaningful and precise relationship exists between the magnitude and direction of the measurements and the average dental-observer responses. The results support the use of this system in dentistry as a means of evaluating color by differences. The further development of such systems for clinical use would be warranted and could serve as a valuable tool for material selection and restoration design, particularly in the area of aesthetic restorative dentistry.
Color↗