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Statement of Problem: The internal and marginal adaptation of a computer-aided design and computer-aided manufacturing (CAD-CAM) prosthesis relies on the quality of the 3-dimensional image. The quality of imaging systems requires evaluation., Purpose: The purpose of this in vitro study was to evaluate and compare the trueness of intraoral and extraoral scanners in scanning prepared teeth., Material and Methods: Ten acrylic resin teeth to be used as a reference dataset were prepared according to standard guidelines and scanned with an industrial computed tomography system. Data were acquired with 4 scanner devices (n=10): the Trios intraoral scanner (TIS), the D250 extraoral scanner (DES), the Cerec Bluecam intraoral scanner (CBIS), and the Cerec InEosX5 extraoral scanner (CIES). For intraoral scanners, each tooth was digitized individually. Extraoral scanning was obtained from dental casts of each prepared tooth. The discrepancy between each scan and its respective reference model was obtained by deviation analysis (μm) and volume/area difference (μm). Statistical analysis was performed using linear models for repeated measurement factors test and 1-way ANOVA (α=.05)., Results: No significant differences in deviation values were found among scanners. For CBIS and CIES, the deviation was significantly higher (P<.05) for occlusal and cervical surfaces. With regard to volume differences, no statistically significant differences were found (TIS=340 ±230 μm; DES=380 ±360 μm; CBIS=780 ±770 μm; CIES=340 ±300 μm)., Conclusions: Intraoral and extraoral scanners showed similar trueness in scanning prepared teeth. Higher discrepancies are expected to occur in the cervical region and on the occlusal surface., (Copyright © 2017 Editorial Council for the Journal of Prosthetic Dentistry. Published by Elsevier Inc. All rights reserved.)

Statement of Problem: Although the postprocessing of digital images with enhancement filters could lead to the presence of artifacts and result in false-positive diagnoses, no study has analyzed whether the use of digital radiographs and/or postprocessing of digital images interferes with the diagnosis of marginal adaptation in metal-restored teeth., Purpose: The purpose of this study was to compare the diagnostic accuracy of conventional and digital radiographic images with and without filters for detecting a misfit between the tooth and restoration in metal-restored teeth., Material and Methods: Forty teeth with mesial-occlusal-distal inlays and 40 with complete crowns (each with a perfect fit, 20 with a 0.2-mm gap and 20 with a 0.4-mm gap) were imaged with conventional film and digital phosphor plate systems. Digital radiographs were exported as original images and with edge enhancement (high and low), inversion, and pseudo-3-dimensional filters. Four examiners assessed the presence of gaps by using a categorical scale (fit, misfit, cannot decide). Sensitivity, specificity, and overall accuracy were calculated for each variable. In addition, time spent scoring the images was recorded. A multivariate logistic regression was performed with accuracy as the dependent variable., Results: Of the images, 6.2% received the score "cannot decide," most of them with a high edge enhancement filter and in the crown group. A tendency for higher sensitivity (range 0.67-0.83), specificity (range 0.81-0.92), and accuracy (range 0.73-0.86) values was found in conventional and digital original images. Results of a logistic regression found that restoration type, gap size, and high enhancement and inversion filters had a statistically significant impact on accuracy (P<.05)., Conclusions: Original nonfiltered images should be used to assess teeth with metal restorations. High enhancement filters and image inversion should be avoided, especially when metal crowns are present., (Copyright © 2015 Editorial Council for the Journal of Prosthetic Dentistry. Published by Elsevier Inc. All rights reserved.)

Statement of Problems: Little is known about the impact of crown margins on the demineralization and remineralization process or on the interpretation of radiographs for the detection of early secondary caries., Purpose: The aim of this study was to correlate the findings from 2 different radiographic techniques with the results of a histologic assessment of carieslike lesions at the crown margin., Material and Methods: Ten fully impacted third molars were extracted and restored with complete metal crowns with chamfer preparations. For each tooth, the prepared margin ended in enamel on one side and extended into cementum/dentin on the other. After being thoroughly cleaned, the teeth were covered with wax except for a 2- x 3-mm window at the crown margin in each of 2 test areas localized at the interproximal enamel and cementum/dentin junction. During demineralization with 6% hydroxyethyl cellulose gel at pH 4.9, direct digital radiographs or conventional radiographs were made at baseline and after 7, 14, 21, and 28 days. Each radiograph was blinded and examined for the presence/absence of lesions by 3 calibrated observers who used predetermined criteria required for receiver operating characteristic (ROC) analysis. After 28 days, the teeth were imbibed with methyl methacrylate and serially ground sectioned for assessment of the lesions in polarized light. Morphometric analysis of lesion extension included the calculation of mean values and standard deviations. Kappa and ROC analysis were applied to assess radiographs made at different demineralization time periods, localization of the crown margins in enamel or cementum/dentin, and direct digital and conventional radiographs. Data were tested for normal distribution (QQ plot), and statistical differences were calculated with Tukey's honestly significant difference post hoc test., Results: Radiographic evaluation revealed only slight interexaminer agreement (Kappa) for enamel lesions (direct digital 0.19, conventional radiographs 0.2) and a fair interexaminer agreement for cementum/dentin lesions (direct digital 0.35, conventional radiographs 0.33). ROC analysis revealed no differences between the radiographic techniques. Lesions localized in cementum/dentin (direct digital 0.86 +/- 0.14, conventional radiographs 0.86 +/- 0.09) were diagnosed more reliably than those in enamel (direct digital 0.79 +/- 0.05, conventional radiographs 0.72 +/- 0.10). As microscopically assessed, the depth of lesions in enamel was less than that of lesions in cementum/dentin (49.3 +/- 7.3 microm vs 89.5 +/- 13.2 microm). Erosions were found in cementum/dentin (depth 25.2 +/- 5.3 microm)., Conclusion: Within the limitations of this study, small artificial lesions were detected equally well by conventional and direct digital radiography. However, because of low interexaminer agreement, the radiographic assessment did not reproduce true histopathologic lesion characteristics documented by morphometry of serial ground sections.

A previously developed radiologic method for determining the thickness of the mineralized crown tissues was applied clinically to 10 teeth diagnosed for extraction. The thickness of the mineralized crown tissues as measured radiographically was compared with that measured directly on the extracted tooth. A statistical analysis indicated accuracy of 4.46%, equivalent to an error of 0.12 mm.

Three clinical methods for testing marginal fit of complete cast crowns were investigated: the exploration, radiograph, and impression techniques. This work proved that the impression technique is the superior test and should become a standard part of the evaluation routine for complete cast crowns.

The dentitions of twenty-eight patients, each of whom had either an autosomal dominant or a sporadic osteogenesis imperfecta (OI) syndrome, were evaluated. The diagnosis of dentinogenesis imperfecta (DI) could be established in all seven patients with dominantly inherited OI in three families, while all eight persons with dominant OI in three other families had normal teeth. Of the thirteen remaining patients with OI, twelve had no family history of the disorder; four had DI and eight had normal teeth. One person had a family history of OI and DI. All patients with abnormal tooth wear and spontaneous tooth fractures had DI. The DMF ratio increased with age in all patients with OI type I and was higher among the patients with OI type III and DI. Class III malocclusions were found in 66% of the patients. A statistically significant high incidence of impacted first and second molars was noted.

Tooth-forming ovarian teratomas provide a unique opportunity to observe the effect(s) of the tumor environment on developing dental structures. Histologic examination of two such teratomas showed essentially normal formation of dental structures in one and pronouncedly aberrant morphodifferentiation of dental tissues in the other. The macroscopic examination of a total of twenty-five teeth from eight additional teratomas showed most teeth to have premolar or molar forms. Most teeth were not distinctly deciduous or permanent but had intermediate shapes. The teeth within a tumor tended not to form normal morphologic sequences. It is concluded that dental structures in ovarian teratomas are products of normal genetic/epigenetic events modified to a greater or lesser degree by unknown factors in the tumor environment.

The purpose of this investigation was to investigate intraoral radiography in regards to the frequency of errors, the types of error necessitating retakes, and the relationship of error frequency to the teeth area examined and type x-ray cone used. The present study used 283 complete mouth radiographic surveys made, and 890 radiographs were found to be clinically unacceptable for one or more errors in technique. Thirteen and one-tenth errors per one hundred radiographs were found in this study. The three major radiographic errors occurring in this study were incorrect film placement (49.9 percent), cone-cutting (20.8 percent), and incorrect vertical angulation (12.5 percent).

Evaluation of the effect of radiographic technique upon the prediction of tooth lengths for all major types of teeth indicated the following: 1. The paralleling technique using the Rinn XCP film holder, the paralleling technique using the hemostat with bite block, and the bisecting-the-angle technique using the Rinn XCP film holder were the most accurate systems. 2. There were no significant differences among the three most accurate techniques. 3. The paralleling technique using a 16-inch tube-to-patient distance was more accurate than the bisecting-the-angle technique using an 8-inch tube-to-patient distance. 4. A beam-guiding film holder produced a more accurate radiographic image than the other film holders used in the study. 5. For the buccal roots of maxillary molars, the bisecting-the-angle technique using the Rinn XCP film holder produced the least mean difference between radiographic image and tooth length. 6. The accuracy of predicting the length of mandibular molar teeth from the diagnostic radiograph was not affected by radiographic technique.

Dental clinicians were asked to distinguish differences in radiographic detail between complete mouth surveys taken with the use of D- and E-speed films. In complete mouth surveys consisting of one half D-speed and one half E-speed films, clinicians could not correctly identify the half of the survey taken with D-speed film 55% of the time. When asked to distinguish surveys consisting entirely of either D- or E-speed films, evaluators could not distinguish D-speed film surveys from E-speed film surveys 42.7% of the time. E-speed film produces diagnostically acceptable radiographs similar in quality to those of D-speed film with the added advantage of an approximate 50% reduction in patient exposure.

The present study was undertaken to determine the correlation between the radiographic appearance of nutrient canals and hypertension. Comparison was made in hypertensive and nonhypertensive patients of the same age group and similar oral status. The results showed an increased incidence of nutrient canals in hypertensive patients.

A simple radiographic measuring method is presented. Fifty teeth to be extracted were radiographed by means of a standardized paralleling technique and a preprinted intraoral radiographic film. The measuring grid was conveyed to the film as a latent pattern by a stenciling process prior to the x-ray exposure. The distance between the measuring lines was adjusted in accordance with the image magnification. The length of the teeth was read directly on the completed radiograph. The extracted teeth were measured by means of a sliding caliper. A statistical analysis of the data indicated that the present method is more accurate than other clinical methods commonly used for determination of tooth lengths.

A new instrument (the Apexfinder) for measuring tooth length was recently introduced for use in endodontics. The procedure of measuring tooth length with this instrument was found to be simple and easy. It also eliminated the need for radiographs, with their problems. One hundred forty-two teeth were used to compare the new method with two different methods, widely used in endodontics, that employ radiographs. The investigation showed that the new technique offers a direct method for measuring the distance between the coronal and apical ends of the tooth. Statistical analysis of the data indicated that the new method was superior to the others. The Apexfinder was accurate in 90 percent of the cases. When radiographs were used, the results were accurate in 75 percent of the cases, while the use of the radiograph and the tooth-length formula gave 60.4 percent accuracy.

Dental xeroradiography, a new imaging system designed specifically for intraoral use, provides a convenient, rapid, low-dose alternative to conventional film radiography. In this study the new imaging system was compared to conventional direct-exposure dental film technique for basic imaging characteristics of contrast, resolution, and noise. Dental xeroradiography proved to be a superior imaging system for demonstrating dental structures and did so at radiation doses one-third of those required for conventional dental (film) radiography.

A method for obtaining periodic identical radiographs with a modified long-cone paralleling technique is described. The appliance consists of a modified Eggen film positioner and an aiming device fastened to a long cone. There was no fixed connection between the film positioner and the x-ray machine. Radiographs have been obtained from twenty-five patients participating in a long-term study of apicoectomy with retrograde root filling. The intervals between the radiographs ranged from 0 to 12 months. A long-term error and a short-term error of the method were found. The method proved to be accurate and fast compared to those described previously.

The use of Dycal combined with gutta-percha cones as a permanent root canal filling material was analyzed. The following experiments were performed: 1. In vitro microscopic analysis of Dycal's adaptation in the dentin wall--gutta-percha cone interphase. 2. Study of the duration period of alkalinity. 3. Clinical and radiograhic posttreatment, inspection and evaluation, and follow-up. The results obtained in these studies showed: 1. There was correct adaptation and adherence of the material. 2. The alkalinity persisted up to 8 months after mixing. 3. There was clinically good postoperative tolerance. 4. Clinical and radiographic success was found in 90 percent of the cases in the treatment of normal vital pulps, vital inflamed pulps, and pulpless teeth with or without areas.

Intraoral radiographs were made via the bisecting-the-angle technique on patients of different ages, sexes, and races. The tooth-film angles for various areas of the mouth were measured and found to be close to 30 degrees for all areas of the mouth except the mandibular posterior regions. The study was conducted to assist in quick positioning of the x-ray beam in difficult cases.

A comparison of the established focal troughs of three panoramic machines with positions of the teeth in the dental arches of 240 patients. The patients, divided into twelve cells, were selected on the basis of race, sex, age, number of teeth, and occlusion. Occlusal registrations were made in fast-set acrylic. Tooth centers were identified and, with the midline-incisal point as a reference point, various composite drawings of tooth positions of patients were made. The total composite of all teeth revealed the striking similarity of the arches. Superimposition on the focal troughs showed that the focal trough of the Panorex easily encompassed all tooth positions. The focal trough of the Orthopantomograph encompassed all tooth positions, although tooth centers lie on the edges of the trough. The focal trough of the GE-3000 with profile index 10 extended so far buccally that many teeth are positioned lingual to the trough. The focal trough of the GE-3000, when reduced uniformly to profile index 7.5, encompasses all tooth positions although some positions fall quite near the borders of the trough.

Transient pulpal vascular ischemia and direct injury to the apices of the teeth have been implicated as the causes of degenerative and atrophic pulpal changes in experimental animals after Le Fort I osteotomy despite the presence of collateral circulation. The long-term clinical effect of these pathologic changes in human teeth has not been studied. Seventeen maxillary third molar teeth from 10 patients whose postsurgical follow-up ranged from 6 months to 78 months (mean, 40 months) were extracted. The long-term biologic effects of Le Fort I osteotomy on the pulp and on the development of teeth were retrospectively evaluated with clinical and standard histologic techniques. Normal teeth from patients who were not operated on were used as controls. Histologic examination revealed an intact pulpal circulation and minimal pathologic changes in the pulpal tissue. Clinical and radiographic studies showed that the growing teeth developed normally after surgery. The Le Fort I downfracture procedure had little discernible long-term effect on the pulp and on the development of human third molar teeth.

Forty-three dried South African Bantu mandibles were examined visually and radiographically for the frequencies of occurrence of apical defects, bifurcation involvements, dehiscences, and fenestrations. Statistical evaluation of the data revealed no significant discrepancy between the visual and radiographic findings.

Case histories of two patients with the whistling face syndrome are presented. The most striking features are microstomia, midface hypoplasia, scoliosis, and retarded growth. Family histories were unremarkable, except possibly in Patient K. B.'s family, where three miscarriages in six pregnancies were noted. Biochemical and chromosome analysis did not reveal obvious changes. The genetics implied a sporadic inheritance pattern.

The precision of tooth-length assessments based on repeated panoramic radiographs made with a Siemens OP 5 was investigated in three groups of twenty patients. Two exposures of the same patient were made under three different radiographic conditions. Of the tooth lengths, nonmeasurability was found in 14% to 17%. The variability (standard deviation) of the measurements assessed from repeated radiographs ranged from 0.65 to 0.85 mm, or 2.4% to 3.1% of the mean radiographic tooth length in the different patient groups. The measurement error ranged from 0.43 to 0.56 mm, indicating that the main source of error inherent in the method was recognition of the reference points. Small differences were found between the tooth groups and between the right and left sides.

This study correlated clinical, radiographic, and histopathologic aspects of 50 endodontic failures involving the paste technique. All clinical and radiographic findings were recorded. The teeth were re-treated with gutta-percha/Kloroperka and lateral condensation. Subsequently, periapical surgery, including retrograde amalgam filling, was performed for the removal of material in the periapical tissue. The resulting biopsy specimens were processed for histologic evaluation. Although neutrophilic leukocytes predominated in some cases, all types of inflammatory cells were present. Macrophages and foreign body cells contained paste particles. The blood pigment distinguished hemorrhage due to surgery from pathologic circulatory changes. There was resorption/apposition of bone and root fragments. Epithelial strands and parts of cyst walls were observed. There was a correlation between a periapical radiolucency and inflammation but no correlation between amounts and types of inflammatory cells and pain. Paste placed beyond the foramen caused tissue damage and reduced prognosis.

This study compared the diagnostic usefulness of images of dental structures made with two xeroradiographic (XR) processes with those made by conventional radiography. The xerographic systems employed were a Xerox 125 system (designed for mammography) as well as a new experimental xerographic instrument designed for dental use. Structures evaluated included osseous trabecular detail, caries, dental anatomy, soft tissue, and dental restorations. In general, the resolution and detail of these dental structures were noticeably better on conventional films than on the XR 125 images. In addition, the presence of artifacts around the margins of metallic restorations on the XR 125 image severely inhibited detection of recurrent caries. In contrast, XR images formed by the new experimental process were equal to or superior to conventional films in resolving detail of dental struitures. Also, the experimental XR process required less radiation exposure than conventional radiography.

Roentgenographic studies of the jaws and teeth in a group of forty-eight pituitary dwarfs showed the following abnormalities in the development of the teeth: 1. Delayed shedding of the deciduous teeth. 2. Absence of resorption of the roots of the deciduous teeth at the usual time. 3. Marked delay in eruption of the permanent teeth. 4. Retention of permanent teeth in the maxillary and mandibular shafts. 5. Development of the apical parts of roots of the retained permanent teeth and their growth toward the lower mandibular edge. 6. Displacement of the first molars from the mandibular shaft to rami. 7. Tilting of some of the retained teeth. 8. Small size of the maxilla and mandible with overcrowding of the teeth in these bones. 9. Complete absence of buds of the wisdom teeth, even in patients in the fourth decade of life. 10. Stimulation of development and eruption of the teeth after administration of anabolic drugs. These abnormalities when present in combination depend on growth hormone deficiency since they do not occur in other types of dwarfism.

Autotransplantation of teeth has been performed for many years and with varying degrees of success. The present report concerns the long-term results of autotransplantation of 36 teeth with completed root formation. Endodontic treatment was started before or within 12 weeks after transplantation. At the final check-up 32 teeth were present, 24 of them without signs of inflammation, replacement, or internal resorption. Careful radiographic examination during the follow-up period and adequate therapeutic measures with inter alia renewed endodontic treatment are of importance for successful autotransplantation.

The rare hereditary disease, dentinogenesis imperfecta, is a disturbance of dentin formation in both the deciduous and permanent dentitions. It may be associated with osteogenesis imperfecta, though it is probably that the two diseases are carried by different genes. This association was recognized in a 19-year-old man. Dentinogenesis imperfecta had been diagnosed at the age of 6 and had been regarded as a mutation; 11 years later, an atypical form of osteogenesis imperfecta developed. The case is atypical because of the apparent absence of dentinogenesis imperfecta in the patient's family. The dental manifestations may have heralded the bone disease.

Orthopantomograms were taken of 111 subjects constituting a random sample of 35-year-old citizens of Oslo. The most frequent pathologic finding was marginal bone loss, which was found in seventy-one persons (64%). Fifty-one impacted and unerupted teeth in twenty-eight persons were seen, the third molars predominating. Ten retained roots were found in nine persons, and apical radiolucent areas were found on forty-four teeth in thirty-three persons. In addition to the pathologic findings, 101 endodontically treated teeth in fifty-five persons were observed.

The definition of the crown-to-root ratio, its manifestation as a clinical problem, and associated problems were reviewed. Treatment possibilities were discussed in terms of plaque control, periodontal surgery, occlusal adjustment by selective grinding, splinting, restorative considerations, and extraction. The original guidelines for crown-to-root ratio in the selection of abutments were found to be exceptionally conservative and treatment limiting. New treatment modalities were considered in light of increased understanding of periodontal inflammation and its control. With inflammation controlled and with a carefully designed occlusion, some degree of mobility may be tolerated, thereby permitting the retention of teeth with minimal alveolar support.

Three cases of odontodysplasia are described, and the literature is reviewed with reference to proposed etiologic mechanisms underlying the pathogenesis of the disorder. The distribution of affected teeth in all four quadrants of one patient is offered as evidence against a somatic mutation as an etiologic mechanism. As infants all three patients had vascular nevi in the facial skin overlying the area where defective teeth developed. Three cases from the literature involved similar vascular lesions. Hypoplastic teeth radiographically similar to odontodysplastic teeth occur in the linear sebaceous nevus syndrome. These findings strongly suggest that local vascular defects are involved in the pathogenesis of odontodysplasia.

This study describes a radiologic method that provides a reliable evaluation of the thickness of the hard crown tissues of the tooth scheduled for prosthetic and conservative preparation. The first stage consisted of calculating the discrepancy between the actual dimensions of the specimen under examination and the dimensions of the same specimen as measured and radiographed. Some coefficients of distortion were calculated for the distance(s) more usually involved clinically. Radiographs were made by using the "paralleling" technique. In the second stage, radiographs were made of 83 extracted teeth (22 incisors, 12 canines, and 51 premolars). On the resulting radiographs some prefixed distances were measured. Finally, to gain an anatomic comparison of the values obtained radiologically, 24 of the previously radiographed teeth were sectioned along the sagittal plane at the diameter, and measurements were made and compared with the radiologic data to which the correction coefficients had been applied.

Intraoral radiograms can be made according to the long tube paralleling technique utilizing aiming devices. An important factor in the design of these instruments is the length of the teeth to be radiographed. Reliable data regarding the length of the teeth in the different regions of the mouth are not available. Information on the length of teeth was therefore collected by measuring 1,400 extracted teeth. A statistical analysis of the data finally resulted for each region of the mouth and for both sexes in length value which could be used for the design of aiming devices.

1. Tooth positions did not vary between ages and sexes in Japanese. 2. As the arches lengthened posteriorly, anterior tooth positions showed little variation. 3. Japanese tooth positions lie within the range shown for Caucasoid and Negroid persons. 4. Japanese tooth positions have a shorter anteroposterior dimension than their Caucasoid and Negroid counterparts. 5. The relationships of Japanese positions to the Panorex, Panelipse, and Orthopantomograph are similar to those found for Negroid and Caucasoid persons.

This study determined the perceived strengths and weaknesses of xeroradiography, D-speed film, and E-speed film for intraoral radiography. Results indicated that xeroradiography was preferred for the imaging of structures useful in periodontics and endodontics whereas film demonstrated a low level of image artifacts and was judged to be better for the imaging requirements of routine restorative dentistry. D-speed film was rated higher than E-speed film. These subjective assessments are similar to previously reported pilot studies but differ from previously published objective studies, which showed no significant difference between the three imaging techniques. Although there are substantial subjective differences between xeroradiography, D-speed film radiography, and E-speed film radiography, all the techniques provide more than the threshold level of necessary diagnostic information and all techniques portray adequate information for evaluation of common abnormalities encountered in the oral cavity.