Digora System Research Articles

Evaluation of Canal Preparation Using One NiTi Instrument with Reciprocating Motion Compared Standard ProTaper File to Gold protaper File (An in vitro study)

The present study compared the shaping efficiency of universal system F2 one file NiTi to one NiTi file gold system with reciprocating motion in curved mesiobuccal roots of maxillary first molars, were randomly divided into two groups, each one 15 roots according to the NiTi system using during shaping the roots, after use of each instrument, the canal was flushed with 5 ml of NaOCL and final rinse with EDTA 17% for 1 minute. Parameter were evaluated: Straighten the curved canals, pre and post canals curvatures images were taken using Standarization technique and analyzed using digital radiography (Digora system), the significant level was set at P<0.05. The result showed that NiTi universal Protaper file produced higher amount and percentage of reduction of canal curvature than gold NiTi file system.

Shaping Ability of Three Ni-Ti Rotary Systems in Curved Root Canals of Extracted Teeth

Aims. The purpose of this study was to compare the effects of 3 different rotary Ni-Ti instruments used to prepare curved root canals on the root canal curvature by using Digora system. Methods. Mesiobuccal canals of 30 mandibular first molars with curvature between 20-40 degrees were divided into 3 equal groups according to Ni-Ti rotary system need for root canal preparation: Alpha, RaCe and ProTaper system. Root canal curvatures from both buccal and proximal view were measured before and after instrumentation by using Digora system and image analysis software according Schneider's technique. Results. The result indicated that ProTaper system showed significantly greater decrease in curvature in the mesio-distal view and in the bucco-lingual view (p<.05). Conclusion. The current study concluded that the rotary Ni-Ti RaCe system better maintained the original root canal curvature than the rotary Ni-Ti Alpha System and ProTaper Universal Systems. It may be better to use the rotary Ni-Ti RaCe system to prepared curved canal in order to maintained the original root canal curvature.

RADIOGRAPHIC EVALUATION OF TELESCOPIC PIER ABUTMENTS IN MANDIBULAR DISTAL EXTENSION CASES

Purpose: The aim of this clinical study is to compare the effect of both definitive partial dentures and telescopic partial dentures on bone height changes around the terminal abutments in mandibular distal extension cases with pier abutment. Materials and Methods: Fourteen mandibular Kennedys Class I classification with pier abutment patients were divided into two equal groups. First group (I) received definitive metal-frame removable partial dentures (RPD), while the second group (II) received telescopic RPD. The supporting bone height around the terminal abutments was radiographically evaluated. Next to baseline recording following denture insertion, bone height measurements were obtained at regular recall follow-up appointments of 6, 12, 18 and 24 months. Radiographic evaluation was carried outusing the Digora system and customized acrylic template constructed for each patient individually. The linear measurement system supplied by the Digora machine software was utilized for recording bone height changes mesial and distal to the main terminal abutments. Results: Comparison was performed between definitive and telescopic groups utilizing independent t-test and resulted in differencesof no significant for all follow-up recalls (P value > 0.05). Conclusion:Definitive RPD and telescopic RPD appeared to besuccessful both clinically and biologically. However, Telescopic RPD proved to be superior to the definitive one regarding bone height measurements.

DIAGNOSTIC ACCURACY OF APPROXIMAL CARIES IN DIGITAL RADIOGRAPH BY CHINESE AND AMERICAN DENTISTS: AN IN VIVO STUDY

<h3>Background</h3> Because dental education system is not the same in both the United States and China, there may be differences between Chinese and American dentists in the radiographic diagnosis of dental lesions. <h3>Objective</h3> The aim of this study was to assess whether there were any differences in the accuracy of diagnosis of approximal caries between Chinese and American dentists. <h3>Materials and Methods</h3> The study was approved by the local ethical committee. Thirty-nine noncavitated teeth were collected from 11 patients who had parts of the upper or lower jaws excised to remove a cyst or neoplasm. Before surgery, radiographs of the involved teeth were taken by using the digital imaging system Digora Optime (Soredex, Helsinki, Finland). The teeth were then sectioned for histologic validation of the lesions. Four Chinese and 4 American dentists and 5 American senior dental students evaluated all of the radiographs according to a 5-category scale. Receiver operating characteristic (ROC) analysis was performed. Repeated-measure analysis of variance (ANOVA) was employed for statistical analysis. <h3>Results</h3> There were no significant differences among the Chinese and American dentists and the American senior dental students (<i>P</i> = .472). Interobserver (<i>P</i> = .67) and intraobserver (<i>P</i> = .24) variances were not significant. <h3>Discussion</h3> Dental education background is not an influencing factor on the accuracy of diagnosis of approximal caries based on digital radiographs.

In vitro comparison of two photostimulable phosphor plate systems for early detection of occlusal dentin caries with and without a sharpening filter.

Background. Dental caries is the most important reason for tooth loss. Clinical examination is the most commonly used technique for occlusal caries diagnosis. The diagnostic power of digital systems is a matter of controversy in this field. The present study aimed to determine the diagnostic accuracy of two photostimulable phosphor plate (PSP) systems for early occlusal dentin caries in vitro. Methods. Sixty-nine extracted molar and premolar teeth were used in this study. The teeth were mounted in triple blocks, and standard radiographs were taken by the Digora and Acteon digital radiographic systems. The original and filter 1-enhanced radiographs were evaluated by two experienced observers twice at an interval of two weeks, and dentin caries was recorded in Tables prepared for the study. The teeth were then sectioned in a buccolingual direction and evaluated under a stereomicroscope. The observers’ reports were compared with microscopic findings as the gold standard. SPSS 23 was used to calculate the kappa coefficient, sensitivity, specificity, and area under the ROC curve (AUC). Statistical significance was set at P<0.05. Results. The internal and the external agreements in both imaging systems were good to excellent. The means of sensitivity, specificity, and AUC in the Acteon system were 34.1, 92.9, and 0.674, with 30.8, 94.8, and 0.659, respectively, in the Digora system. Conclusion. The accuracy of early occlusal caries diagnosis was poor on both systems, and no significant difference was observed between the two systems at a 95% confidence interval. Although the AUC was slightly higher in the original images, there was no significant difference between them; however, due to their high specificity, they can prevent unnecessary treatments in the clinic.

Radiopacity analysis of humidity influence on the solubilization of different retrograde filling materials

Introduction and Objective: This study aimed to analyze the level of radiopacity of different materials used in endodontic retrofilling procedure regarding the nfluence of humidity on solubilization over a period of 30 days. Material and ethods: 10 specimens with 10 mm diameter and 1mm thick were made with each of the materials. The following retrograde filling materials were tested: lass ionomer Vitro Fil LC®, IRM®, MTA Angelus®, Sealer 26® and silver malgam capsule DFL Alloy. These materials have been handled by a ingle operator, according to the recommendations of their ective manufacturers. The obtained specimens were surrounded by moist gauze and incubated in a heater for thirty days at 37°C and 100% humidity. The mples were x-rayed, via the digital system Digora Optime®, at three different oments: first, 15th, and 30th day of incubation. For the analysis of radiopacity f the samples, the shades of gray were measured through ImageTool® software. Results and Conclusion: Data were subjected to statistical analysis using NOVA, repeated measures design, followed by Tukey test with a ignificance level of 5%. According to the results, it could be observed that e only tested materials that have undergone changes in radiopacity, in ccordance with the period of incubation in humidity, were theglass ionomer Vitro Fil LC® and Sealer 26®.

Radiopacity analysis of humidity influence on the solubilization of different retrograde filling materials

This study aimed to analyze the level of radiopacity of different materials used in endodontic retrofilling procedure regarding the influence of humidity on solubilization over a period of 30 days. Material and methods: 10 specimens with 10 mm diameter and 1mm thick were made with each of the materials. The following retrograde filling materials were tested: glass ionomer Vitro Fil LC®, IRM®, MTA Angelus®, Sealer 26® and silver amalgam capsule DFL Alloy. These materials have been handled by a single operator, according to the recommendations of their respective manufacturers. The obtained specimens were surrounded by moist gauze and incubated in a heater for thirty days at 37°C and 100% humidity. The samples were x-rayed, via the digital system Digora Optime®, at three different moments: first, 15th, and 30th day of incubation. For the analysis of radiopacity of the samples, the shades of gray were measured through ImageTool® software. Results and Conclusion: Data were subjected to statistical analysis using ANOVA, repeated measures design, followed by Tukey test with a significance level of 5%. According to the results, it could be observed that the only tested materials that have undergone changes in radiopacity, in accordance with the period of incubation in humidity, were the glass ionomer Vitro Fil LC® and Sealer 26®.

COMPARATIVE STUDY OF SHAPING ABILITY OF REVO-S AND ONE SHAPE NICKEL-TITANIUM ROTARY SYSTEMS IN CURVED ROOT CANALS. (AN IN VITRO STUDY)

Aim of the study: was to compare the shaping ability of One Shape, Revo-S NiTi rotary instruments, and stainless steel K-Flexofile instruments when used to prepare curved root canals. Methodology: A total of sixty mesiobuccal root canals of extracted human permanent mandibular molars were used. Those had curvature ranging between 200- 400, radius of curvature between 4-10 mm, and length of curved part between 6-8 mm. The samples were divided into three groups of 20 teeth each according to the instrument used. Using Digora system, the degree of straightening was calculated by comparing pre and post-instrumentation radiographs. Using cone beam computed tomography, mesial and distal dentin thicknesses were measured pre and post- instrumentation, and then applied in an equation given by Gambill et al., to calculate the centering ratio and transportation of the canals. Both rotary systems showed good centering ability and less canal straightening and transportation compared with stainless steel K-Flexofile, with no significant difference between the rotary systems. Results: Tukey’s pair-wise test showed that K-Flexofile showed the highest mean degree of straightening, degree and direction of canal transportation and the centering ability while One Shape had the lowest mean. No statistically significant difference was found between One Shape and Revo-S. Conclusion: Both rotary systems caused less transportation and remained better cantered in the canal than stainless steel K-Flexofile instruments, with no significant difference between One Shape and Revo-S.

Pixel value analysis for detection of simulated early external root resorption

The aim of this study was to determine the efficacy of pixel value analysis using images generated by the Digora™ and Visualix™ systems for the early detection of external root resorption (ERR). Thirty extracted human lower incisors were radiographed using the Digora and Visualix systems; then, ERR was induced by immersing the teeth in 6 mol L-1 of hydrochloric acid for different periods of time (10, 30 and 60 minutes). ERR was confirmed by calcium quantification with an atomic absorption spectrophotometer. One digital image was acquired per time period at 70 kVp, 7 mA, 2.2 mm filtration, focus-film distance of 30 cm, and with exposure times of 0.09 s in the Digora system and 0.05 s in Visualix system. The region of interest was defined using ImageJ software. Statistical analysis was performed using ANOVA and Pearson's correlation (p < 0.05). There was no statistically significant difference between the time for ERR induction and the pixel values with either system. A positive correlation between the time of ERR induction and the calcium concentration was observed (r = 0.8892; p < 0.001). In conclusion, independent of the site of ERR induction and the digital system, pixel value analysis was not effective for ERR detection.

A method for the geometric standardization of intraoral radiographs for long‐term follow up of replanted teeth: a case report

The interpretation of the set of radiographs taken during the follow-up period after tooth replantation might pose several difficulties, especially the inability to adequately reproduce the projection geometry of the exposures. This article describes a method for the geometric standardization of intraoral radiographs using a custom-made apparatus comprising a film-holder attached to an occlusal splint for the long-term follow up of dentoalveolar trauma. The method was applied in a patient who suffered an avulsion of the maxillary central incisors and had the teeth replanted after 4 h in saline storage. Endodontic treatment started 7 days after the trauma with changes of a calcium hydroxide intracanal medication every 15 days in the first 2 months and thereafter at 30-day intervals for 8 months. Root canal filling was carried out after this period. The radiographic exposures taken at the follow-up visits were standardized to identify the possible alterations during the repair process, such as root resorptions. A maxillary arch impression was made with alginate, and the model was cast in stone for fabrication of an acetate occlusal splint. The custom-made apparatus used for standardization of the radiographic exposures was fabricated by fixing a Rinn X-C-P film-holder and a 5-mm-long piece of 0.7-mm orthodontic wire to the occlusal splint with autopolymerized acrylic resin. Radiographs were taken at 4-month intervals, starting 10 months after replantation up to 76 months. The images were digitized and analysed using the Digora system. The length of the central incisors was determined to verify the reproduction of the projection geometry of the exposures and the orthodontic wire served to assess accuracy during length estimations in the radiographs. The method described in this article for geometric standardization of intraoral radiographs provided a consistent reproduction of the geometric exposure parameters, being indicated for use in the radiographic follow up of cases of dentoalveolar trauma.

From ophthalmologist to dentist via radiology.

The aim of this paper was to analyze the causes of orbital cellulitis in connection with covert dental changes as well as to establish the role of radiological procedures in the final diagnosis and further treatment of such cases. Thirty-two patients, aged 25-56, 22 women and 10 men were diagnosed and treated between January 2007 and April 2011 at the Pomeranian Medical University in Szczecin. The patients were examined in the infirmary of the ophthalmological department due to unilateral blepharo-oedema, abrupt pain and vision disturbances; in 5 cases, body temperature increased up to 37.8°C was observed. Next, the patients underwent conventional X-ray examinations of the orbit to exclude any foreign bodies in the eyeball, as well as pantomographies to evaluate the dental status. Visible periapical or periodontal changes in dentition were analyzed with intraoral X-rays with the use of DIGORA System 2.1. Changes found in 3 patients on pantomograms and connected with iatrogenic procedures were further evaluated with CT (64 lines and 128 layers) in frontal, sagittal and axial projections. Orbital disorders were also diagnosed by an ophthalmologist and radiologist with Doppler ultrasound (US) examinations. A linear transducer of 7.5-10 MHz to observe the morphology and vascularity of the eyeball was applied. IATROGENIC TREATMENT WAS THE CAUSE OF SINUSITIS AND CELLULITIS IN THREE CASES: incorrectly implanted dental implant in one case, root of the 3(rd) molar pushed into the sinus in the second case, and communication between the maxillary alveolar process and the sinus after extraction in case of the third patient. Asymptomatic periapical osteolysis, periodontal disease or dead teeth were found in all cases. Diagnosis of orbital cellulitis of dental origin was determined on the basis of clinical, radiographic and ultrasound findings. Ophthalmologic and dental treatment was applied simultaneously. Co-operation between ophthalmologists, radiologists and dentists is necessary during the treatment of such orbital diseases.

Detection accuracy of proximal caries by phosphor plate and cone-beam computerized tomography images scanned with different resolutions

This study was carried out to assess whether the spatial resolution has an impact on the detection accuracy of proximal caries in flat panel CBCT (cone beam computerized tomography) images and if the detection accuracy can be improved by flat panel CBCT images scanned with high spatial resolution when compared to digital intraoral images. The CBCT test images of 45 non-restored human permanent teeth were respectively scanned with the ProMax 3D and the DCT Pro scanners at different resolutions. Digital images were obtained with a phosphor plate imaging system Digora Optime. Eight observers evaluated all the test images for carious lesion within the 90 proximal surfaces. With the histological examination serving as the reference standard, observer performances were evaluated by receiver operating characteristic (ROC) curves. The areas under the ROC curves were analyzed with two-way analysis of variance. No significant differences were found among the CBCT images and between CBCT and digital images when only proximal enamel caries was detected (p = 0.989). With respect to the detection of proximal dentinal caries, significant difference was found between CBCT and digital images (p < 0.001) but not among CBCT images. The spatial resolution did not have an impact on the detection accuracy of proximal caries in flat panel CBCT images. The flat panel CBCT images scanned with high spatial resolution did not improve the detection accuracy of proximal enamel caries compared to digital intraoral images. CBCT images scanned with high spatial resolutions could not be used for proximal caries detection.

Diagnostic accuracy of proximal caries by digital radiographs: an in vivo and in vitro comparative study

The aim of this study was to evaluate if the diagnostic accuracy of proximal dental caries in digital radiographs was similar when obtained in in vivo and in vitro conditions. Thirty-nine noncavitated teeth were collected from 11 subjects who had part of upper or lower jaws excised owing to cyst or neoplasm. Before operation, radiographs of the teeth involved were taken with the digital imaging system Digora Optime (Soredex, Helsinki, Finland), and after operation, the same extracted teeth were mounted in plaster blocks and exposed with the same digital imaging system. The teeth were subsequently sectioned for histologic validation of the lesions. Six observers evaluated all of the radiographs according to a 5-category scale. Receiver operating characteristic analysis was performed. Repeated-measure analysis of variance was used for the statistical analysis. There were no significant differences between digital radiographs taken in in vivo and in vitro conditions for diagnosis of proximal dental caries (P = .286). Detection accuracy of proximal dental caries obtained from an in vitro study can be considered to be representative of diagnostic accuracy of proximal dental caries obtained in the real clinical situation.

Effect of Atorvastatin in radiographic density on alveolar bone loss in wistar rats

The purpose of this study was to evaluate the effect of Atorvastatin (ATV) on alveolar bone loss induced in rats. Periodontitis was induced by ligature placement around the upper second left molar in a total of 24 male Wistar rats (± 200 g). Groups of 6 animals received via oral gavage either saline or ATV (1, 3 and 9 mg/kg) during 11 days. After this time, the animals were sacrificed and their maxillae were removed, defleshed, radiographed by Digora System®, and latter stained to be photographed using a digital camera. Data were analyzed statistically by ANOVA and Bonferroni test at 5% significance level and presented as mean ± SEM. ATV (9 mg/kg) caused a significant increase on gray tone variation of over 48% (118.3 ± 12.0 gray tones) when compared to saline (79.8 ± 6.2 gray tones), indicating greater radiographic density. These data were corroborated by macroscopic findings, where ATV (9 mg/kg) reduced alveolar bone loss by over 47% (p<0.05), when compared to the group of untreated animals (saline). In summary, ATV was able to prevent alveolar bone loss seen on a ligature-induced periodontitis model.

Detection of Artificial Occlusal Caries in a Phosphor Imaging Plate System with Two Types of LCD Monitors Versus Three Different Films

The aim of this study was to determine diagnostic performance of a storage phosphor plate system Digora Optime (Soredex, Helsinki, Finland) with two types of LCD monitor in the detection of artificial caries when compared to Ultraspeed (D), Ektaspeed Plus (E), and Insight (F) radiographic films. Seventy extracted human molars-with artificial caries-were radiographed under identical standardized conditions using (1) a storage phosphor plate system Digora (Soredex, Helsinki, Finland), (2) Insight, (3) Ektaspeed Plus, and (4) Ultraspeed (Carestream Health Inc, Rochester, NY). All digital images and radiographs were examined by three observers for the presence or absence of artificial caries using a five-point confidence scale. Digital images were evaluated both on a LCD computer monitor (Philips 170S, Holland) and medical monitor-3 megapixel monochrome display (Me355i2, Totoku, Tokyo)-with brightness and contrast enhancement. Observer responses were evaluated using ROC analysis and other measurements for diagnostic accuracy. Storage phosphor images with medical monitor demonstrated higher mean A (z) values (0.70 +/- 0.08) than digital images with computer monitor and conventional films. Storage phosphor images with medical monitor presented the highest score, 0.97, 0.90, 0.94, for each observer, respectively. Also, true positive observations (0.82) and positive likelihood ratios (2.71) were higher in enhanced storage phosphor images with medical monitor. Caries detection of mechanically created lesions by experienced radiologists is roughly comparable when examining D-speed film images and Digora images on both the computer and medical LCD monitors, and appears to be poorer on E- and F-speed film images.

Evaluation of the effects of processing delays and protective plastic cases on image quality of a photostimulable phosphor plate system

This ex vivo study evaluated the quality of digital radiographic images obtained with the photostimulable phosphor plate system (Digora) according to the processing delay and maintenance of optical plates in either opaque (supplied with the system) or transparent protective plastic cases during this period. Five radiographs were obtained from the mandibular molar region of a dry human mandible using optical plates. These plates were placed in the protective plastic cases before obtaining the radiographs and were processed immediately or after processing delays of 5, 60 and 120 min, when the case was removed. The results revealed a reduction in image quality when processing was delay 120 min compared to the other times. The opaque case provided better protection to the sensor than the transparent case. In conclusion, a 120-min processing delay for the Digora system caused a reduction in image quality, yet without interfering with the quality of diagnosis. The opaque case supplied by the system's manufacturer provided better protection to the optical plate than the transparent case.

In vitro analysis of the radiodensity of indirect composites and ceramic inlay systems and its influence on the detection of cement overhangs

The purpose of this study was to evaluate the radiodensity of indirect restorative systems and to determine its influence on detection of resin cement overhangs. Sixty sound molars with similar dimensions were selected, and MOD inlay preparations were made in a standardized fashion with 6 degrees taper of the walls. Restorations were made with a porcelain, Duceram LFC, and with three indirect composites, Solidex, Artglass, and Targis. Digital radiographic images were taken before and after cementation of the inlays (Digora system) and were analyzed on two regions, the cervical and the isthmus floor. Digital radiodensity measurements were performed on standardized points symmetrically distributed over each restoration and tooth structure. Cement overhangs were detected through visual analysis by three evaluators. Data were statistically analyzed utilizing ANOVA following Tukey's test (p < 0.05), showing that Solidex presented lower radiodensity than Duceram LFC, and both Artglass and Targis presented similar higher levels of radiodensity than the other groups. Radiodensity of cervical regions was always greater than for isthmus floor regions. Detection of the resin cement overhangs is easier observed on Solidex and Duceram LFC. Radiodensity is highly influenced by restorative material type and tooth regions. The detection of radiopaque resin cement overhangs is influenced by radiodensity of restorative materials.

Análise de Defeitos Ósseos Utilizando a Radiografia Convencional e Sistema de Imagem Digital Digora

This study evaluated the accuracy of conventional radiography and photostimulate phosphor plate system in localizing and visualizing experimentally created bone defects.Dry human mandibles with good bone integrity in the evaluated regions were selected. The bone defects were performed on the mandibule external face from the central incisors to the first premolar and within the posterior teeth sockets, using round burs # 2, 4, 6, 8 and 10, in low rotation.The mandibles were radiographed with Ekta-speed Plus EP-21 Kodak film and optical plates of the Digora system. The visualization of bone defects was performed in the radiographic images, with the aid of a viewbox; in the digital images (standard, 3D, contrast inversion), it was performed in the computers screen, with the support of Windows for Digora software. The findings showed that the bone defect in cortical bone are best viewed in conventional radiography and in cancelous bone are best in digital images. When digitized images were compared it was observed that standard and contrast invertion images were more accurate than those in 3D, in the visualization of bone defects.

Reproducibility of pixel values for two photostimulable phosphor plates in consecutive standardized scannings

The objective of the present study was to determine the reproducibility of the pixel values obtained with the Digora system (Soredex, Finland). Exposures were standardized, with variation in exposure and scanning time of two photostimulable phosphor plates containing a stepwedge image. The smallest variation in pixel values ranged from 50 to 75%, with the widest variations being observed in less dense steps. A significant difference in pixel values was observed in terms of X-ray exposure and scanning times and between the two plates themselves (ANOVA, p < 0.01). Using the present methodology, the reproducibility of pixel values was not satisfactory for the tested white photostimulable plates. This wide variation in digitalization might be influenced by the amount of X-rays that sensitized the plates. It may be important to establish the reproducibility of the pixel values in quantitative studies using digital image.

Interexaminer agreement in caries radiographic diagnosis by conventional and digital radiographs

The purpose of this research was to compare two digital storage phosphor systems and conventional film, as well as verify the interexaminer agreement in radiographic diagnosis on occlusal and proximal cavities. Two digital systems and conventional radiographic film were used to evaluate 144 tooth surfaces with and without cavities; the radiographs were analyzed and scored in a scale of 4 points. Thirteen undergraduates and an oral radiologist participated as examiners. A light microscopy analysis was accomplished in order to validate the research. The results showed that there was no significant difference between the radiographic systems, however all of them had significant differences when compared to light microscopy, except for the Digora system on the proximal surface when the radiologist was the examiner. In the interexaminer evaluation, a moderate agreement level was obtained, and a fair to moderate level was obtained between the students and the oral radiologist. Regarding the validation (sensitivity, specificity, positive predict and negative predict) the values were similar between students and the oral radiologist, except for the sensitivity value on the occlusal surface. The students had the highest number of false-positive results and the oral radiologist the highest number of false-negative results.