Secondary caries detection by DIAGNOdent and radiography: a comparative in vitro study

DIAGNOdent is now well documented for detection of primary occlusal caries, but not as yet for secondary caries. The aim of this study was to investigate the application of DIAGNOdent for in vitro detection of secondary caries. The material comprised 66 extracted teeth: 48 with amalgam restorations and 18 with tooth‐colored restorations. Digital images of occlusal surfaces were captured for each specimen. The teeth were mounted in groups of 3 or 4 in plaster blocks simulating their anatomical positions. Bitewing radiographs of each block were assessed for secondary caries by 5 observers. The margins of each restoration were carefully scanned with DIAGNOdent; the site of the highest reading was localized in digital images; and the corresponding values were registered. Marginal integrity and staining were also documented. The restorations were then removed and the teeth were hemi‐sectioned. For verification, two observers working together examined all the cavities under a stereomicroscope at 16 x magnification followed by probing. Sensitivity and specificity for DIAGNOdent and conventional radiography were 0.77/0.81 and 0.65/0.81, respectively. Regarding ROC analyses, the A _z values were 0.89 and 0.72 for DIAGNOdent and radiography. For DIAGNOdent, the false‐positive fraction included only stained teeth. Cohen's kappa statistics disclosed moderate agreement between the 2 methods, with an agreement of 56%. DIAGNOdent tended to give more positive diagnoses than bitewing radiography. The results indicate that DIAGNOdent may be a helpful tool for detecting secondary caries.     

Secondary caries detection by DIAGNOdent and radiography: a comparative in vitro study

DIAGNOdent is now well documented for detection of primary occlusal caries, but not as yet for secondary caries. The aim of this study was to investigate the application of DIAGNOdent for in vitro detection of secondary caries. The material comprised 66 extracted teeth: 48 with amalgam restorations and 18 with tooth-colored restorations. Digital images of occlusal surfaces were captured for each specimen. The teeth were mounted in groups of 3 or 4 in plaster blocks simulating their anatomical positions. Bitewing radiographs of each block were assessed for secondary caries by 5 observers. The margins of each restoration were carefully scanned with DIAGNOdent; the site of the highest reading was localized in digital images; and the corresponding values were registered. Marginal integrity and staining were also documented. The restorations were then removed and the teeth were hemi-sectioned. For verification, two observers working together examined all the cavities under a stereomicroscope at 16 x magnification followed by probing. Sensitivity and specificity for DIAGNOdent and conventional radiography were 0.77/0.81 and 0.65/0.81, respectively. Regarding ROC analyses, the Az values were 0.89 and 0.72 for DIAGNOdent and radiography. For DIAGNOdent, the false-positive fraction included only stained teeth. Cohen's kappa statistics disclosed moderate agreement between the 2 methods, with an agreement of 56%. DIAGNOdent tended to give more positive diagnoses than bitewing radiography. The results indicate that DIAGNOdent may be a helpful tool for detecting secondary caries.     

Assessment of simulated internal resorption cavities using digital and digital subtraction radiography: a comparative study

Abstract – Aim: To compare the diagnostic accuracy of digital radiography with that of digital subtraction radiography in the detection of simulated internal resorption cavities. Materials and Methods: Simulated internal resorption cavities of varying sizes were created using round burs in 18 single‐rooted teeth with visible pulp chamber, which had been extracted from dentate dry mandibles and split into two halves in a mesio‐distal direction. Resorption cavities were created in the buccal half of the root in the cervical, middle, and apical third. Digital radiographs were taken from three different horizontal view angles before and after the creation of the cavities. This process was followed by digital subtraction radiography to evaluate their detection. Seven experienced observers and all specialists in endodontics were asked to examine the digital and digital subtraction images for the presence of the cavities. The data were analyzed using SPSS 14. Results: The overall sensitivity of digital subtraction radiography was superior to digital radiography and with statistically better results for all cavities regardless of their location (cervical, middle, apical third) (P < 0.05). The detection of the cavities was affected by the root third in which they were located. Cavities in the apical third were more easily detected compared with those in the middle or cervical third of the root. Small‐sized lesions (0.5 mm, 0.6 mm) in the middle and apical third were more frequent and more easily detected using subtraction imaging. Conclusion: Digital subtraction radiography is superior to digital radiography for the detection and monitoring of the progress of internal root resorption.     

Radiation absorbed from dental implant radiography: a comparison of linear tomography, CT scan, and panoramic and intra-oral techniques

Absorbed radiation dose in bone marrow, thyroid, salivary gland, eye, and skin entrance was determined by placement of lithium fluoride thermoluminescent dosimeters (TLD's) at selected anatomical sites within and on a human-like x-ray phantom. The phantom was exposed to radiation from linear tomographic and computer-assisted tomographic (CT) simulated dental implant radiographic examinations. The mean dose was determined for each anatomical site. Resulting dose measurements from linear tomography and computer-assisted tomography are compared with reported panoramic and intra-oral doses. CT examination delivered the greatest dose, while linear tomography was generally lowest. Panoramic and intra-oral doses were similar to those of linear tomography.     

Accuracy of linear temporomandibular joint measurements with cone beam computed tomography and digital cephalometric radiography

INTRODUCTION: Cone beam computed tomography (CBCT) is making headway into imaging for orthodontics. The purpose of this study was to define CBCT multi-planar reformatted projections for temporomandibular joint (TMJ) examination and compare the accuracy of linear measurements of the TMJ and related structures from these projections with similar measurements made with conventional cephalograms and with the anatomic truth. METHODS: Linear dimensions between 11 anatomical sites were measured with a digital caliper to assess the anatomic truth for 25 dry human skulls. The skulls were imaged with iCAT (Xoran Technologies, Ann Arbor, Mich/Imaging Sciences International, Hatfield, Pa) CBCT, and cephalograms were made in all 3 orthogonal planes (lateral cephalometric [LC], posteroanterior [PA], and submentovertex [SMV]) acquired with photostimulable phosphor plates. Linear measurements were made on 7 custom CBCT reconstructions and the digital cephalograms. Modality means and the natural log of the standard deviations were compared post hoc against the actual dimensions by using analysis of variance with the Dunnett t test. Significance was set at P < .05. RESULTS: All CBCT measurements were accurate; however, 3 of 5 LC measurements, 4 of 5 PA measurements, and 4 of 6 SMV measurements varied significantly from the truth. Intraobserver CBCT measurements were highly reliable compared with anatomic truth and significantly more reliable than measurements made from LC, PA, and SMV images. CONCLUSIONS: Custom oblique multi-planar reformatted reconstructions with iCAT CBCT provide accurate and reliable linear measurements of mandibular and TMJ dimensions.     

Mouthrinses: a comparative microbiological study.

This study was performed in order to evaluate the efficacy of different mouthrinses whose use is extended in Spain. Six different antiseptic mouthrinses were studied by means of determination of Minimal Inhibitory Concentration (MIC) values against Klebsiella pneumoniae, Serratia marcescens, Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus, Salmonella typhimurium, Bacillus subtilis, Streptococcus mutans, Prevotella intermedia, Porphyromonas gingivalis and Actinobacillus actinomycetemcomitans. Also in vivo experiments were carried out in volunteers by the use of mouthrinses and evaluation of bacterial populations before and after the treatment. Finally, the kinetics of bacterial death was determined. Results suggested that the determination of MIC values is not a reliable method to evaluate the antibacterial effect of such products. On the other hand those rinsing solutions based on the effect of oxygen, such as those containing carbamide peroxide have a greater efficacy against anaerobic bacteria compared with rinses whose active molecule is a disinfectant. Finally, the kinetics of bacterial death demonstrates that the essential oil rinse kills bacteria much faster. All tested mouthrinses were active as antibacterial although those based on oxygen production or essential oils were more active than solutions based on chlorhexidine and Triclosan.     

Canal transportation after root canal instrumentation: a comparative study with computed tomography

This in vitro study used computed tomography (CT) to compare the occurrence of canal transportation in the apical third of mesiobuccal canals in maxillary molars instrumented with 3 techniques. Sixty teeth were assigned to 3 groups (n = 20), and the root canals were instrumented as follows: Group 1, hand instrumentation with K-files; Group 2, K-files coupled to an oscillatory system powered by an electric engine; Group 3, ProTaper NiTi rotary system powered by an electric engine. To compare the canal transportation produced by the different techniques, preinstrumentation and postinstrumentation 3-dimensional CT images were obtained from root cross-sections of the region located 3 mm short of the apical foramen of each root canal. The CT scans were exported to Adobe Photoshop software, and the initial and final images were superimposed to detect the root canal wall differences between them. Canal transportation was measured by the distance between the prepared canal center and the anatomic canal center. The manual technique produced lesser canal transportation (0.10 mm) than the oscillatory and rotary techniques (0.37 and 0.22 mm, respectively); this difference was statistically significant (P=.021). All studied techniques produced canal transportation.     

Evaluation of two-dimensional lateral cephalogram and three-dimensional cone beam computed tomography superimpositions: a comparative study

Superimposition of radiographic imaging is used to evaluate patient growth and the effects of surgical and/or orthodontic treatment. The purpose of this study was to compare the outcomes of superimposition between two-dimensional (2D) and three-dimensional (3D) superimpositions. 2D lateral cephalograms were generated from the initial and final cone beam computed tomography scans (CBCT) of 18 patients and superimposed. Both 3D CBCT and 2D CBCT generated lateral cephalograms were oriented to the Frankfort horizontal plane and superimposed according to the American Board of Orthodontics recommendations. Changes in landmark position were quantified from the resulting superimposition outcomes via linear measurements made with Dolphin software. Differences between the two methods were analyzed using paired t-tests. Measurements were repeated twice for 10 randomly selected scans to assess reliability by intra-class correlation coefficient (ICC) analysis. Intra-examiner reliability was high for all measurements (ICC > 0.84). Agreement between 2D and 3D superimposition outcomes, as measured by P-values, was low for ANS (P = 0.026), B-point (P < 0.001), ST Upper lip (P = 0.019), U1 tip (P = 0.010), and U1 apex (P = 0.026). 2D measurements were significantly higher than 3D measurements for ANS, B-point, ST Upper lip, U1 tip, and U1 apex. Findings indicated that both methods of superimposition (2D and 3D) are highly reliable. Statistical differences between 2D and 3D superimposition outcomes were below the threshold of clinical significance.     

The importance of radiography in the diagnosis of TMJ dysfunctions: A comparative evaluation of transcranial radiographs and serial tomography

Eight men and 22 women with TMJ pain-dysfunction syndrome were selected. After clinical examination, TR and serial tomography were performed in 5 to 7 different planes. In 27 patients, TR showed a condylar displacement. This was confirmed by serial tomography, which also showed that the apparent position may vary from the medial to the lateral aspects due to rotation in some patients. Changes in shape were a common feature and did not necessarily occur in the same manner on each side or in the different sections of the same condyle. In these patients, the TR shape was generally more similar to that of the middle and lateral tomographic planes. The relationship between remodeling pattern and condylar position was confirmed. Degenerative lesions were present in some patients but could only be clearly detected by serial tomography.This study confirms the important role of the TMJ in dysfunctions and the validity of radiography in diagnosis.     

Accuracy of integration of dental cast and cephalograms compared with cone-beam computed tomography: a comparative study

Odontology - This study proposes a method that integrates maxillary dental cast and cephalograms and evaluates its accuracy compared with cone-beam computed tomography (CBCT) scans. The study...     

Reproducibility of rotational panoramic radiography: mandibular linear dimensions and angles

The reproducibility of nine mandibular variables (linear dimensions and angles) assessed from panoramic radiographs with the Orthopantomograph 5 (Siemens) was investigated. Attention was given to the possible influence of recording the reference number of the head positioner with one or two radiographers. Two separate exposures of three groups of patients were made under different radiographic conditions, each group representing one method. Acceptable reproducibility was observed for the vertical and angular variables, the method variance being mostly within 3% of the total variance. Horizontal variables were clearly more unreliable. No statistically significant differences were observed between the reproducibility of the right and left sides. A negative correlation was found between the angular variables within two groups. For most variables, only small differences among the methods were found. The highest reliability was obtained when the same radiographer recorded the reference number of the head positioner and made both exposures. An accuracy study on five dried skulls showed an image magnification of approximately 18% to 21% for the vertical variables, whereas the gonial angle assessed from a panoramic film was almost identical to that measured on the dried mandible.     

Shaping ability of reciprocating motion in curved root canals: a comparative study with micro-computed tomography

Introduction

Recently, root canal shaping with reciprocating motion has been postulated to reduce the possibility of unexpected file fractures. However, there has been little information on the shaping capability of this reciprocating motion preparation technique. Therefore, the purpose of this study was to evaluate the shaping ability of reciprocating motion when compared with continuous rotation motion in curved root canals.

Methods

The mesiobuccal and distobuccal canals of 20 extracted maxillary molars with curvatures of 20-45 degrees were instrumented with a series of ProTaper rotary files. The canals in the continuous rotation motion (CM) group (n = 20) were prepared by using continuous rotation with pecking motion, whereas the canals in the reciprocating motion (RM) group (n = 20) were prepared with reciprocating motion (clockwise 140 degrees and counterclockwise 45 degrees). Basic geometric parameters such as curvature, root canal volume, surface area, and structure model index (SMI) before and after canal shaping were evaluated by using micro-computed tomography. The degrees and directions of transportation were also measured, and statistical analysis was carried out with one-way analysis of variance and Tukey post hoc tests.

Results

There were no significant differences between the 2 groups in canal curvature, volume, surface area, and SMI categories measured before preparation (P > .05). Changes in curvature, root canal volume, surface area, and SMI were not affected by the instrumentation technique used (P > .05). There were no significant differences in the degrees and directions of transportation between CM and RM groups (P > .05).

Conclusions

The application of reciprocating motion during instrumentation did not result in increased apical transportation when compared with continuous rotation motion, even in the apical part of curved canals. Reciprocating motion might be an attractive alternative method to prevent procedural errors during root canal shaping.     

Direct digital extraoral radiography of the head and neck with a solid-state linear x-ray detector.

A narrow fan beam of x-rays intercepted by a linear array detector was used to acquire transmission data for a radiographic phantom moved across the beam. The digital data were displayed as images representing a variety of extraoral views of the head and neck. Projections investigated include the straight lateral view, two frontal projections, and a half-axial projection. The digital images appear to provide adequate contrast and resolution for common diagnostic tasks. In addition, the use of a scanning linear detector reduces the amount of scatter, which increases contrast relative to images made with an area detector. The system appears to provide a versatile and convenient means for the acquisition of extraoral views relevant to dental practice while it eliminates the logistical difficulties and errors associated with film processing.     

Industrial dental erosion: a cross-sectional, comparative study.

Occupational exposure to sulphuric acid mist (H2SO4) is a health hazard. The threshold limit value-time weighted average (TLV-TWA) of exposure to H2SO4 recommended by the American Conference of Governmental Industrial Hygienists (ACGIH, 1994-1996) is 1 mg/m3. This single-blind study conducted in an electro-winning facility in South Africa, compared dental erosion of anterior and premolar teeth of male workers exposed daily to H2SO4 in an exposed group (H2SO4 range: 0.3 mg/m3-1 mg/m3) and an unexposed group (H2SO4 range: 0.1 mg/m3-0.3 mg/m3). The exposed group comprised all workers at the facility exposed to the aforesaid range of H2SO4 (N = 103). A total of 102 unexposed subjects similar in composition with respect to age and length of service were randomly selected from the rest of the 700 workers at the facility. A questionnaire was administered to seek information on possible worker habits associated with dental erosion and to determine perceptions of oral function. Clinical examinations assessed prevalence and severity of dental erosion. The mean age of subjects was 31.4 years and mean length of service 4.2 years. In the exposed group 48% complained of pain and sensitivity on their teeth compared with the 31% of unexposed persons (P = 0.020). Dental erosion was present in exposed (96%) and unexposed (75%) subjects. Exposed subjects were more likely to develop erosion than unexposed subjects, the odds ratio being 5.531 within the confidence limits 2.167 < OR < 14.117. There was a significant difference in the severity of tooth surface loss between exposed and unexposed groups (P = 0.001). Dental erosion was most severe in the anterior teeth and occurred mostly on the labial and incisal surfaces.     

Disinfection of irreversible hydrocolloid impressions: a comparative study.

This paper demonstrates the potential for cross contamination with bacteria and viruses from impression materials and evaluates the efficacy of four disinfection systems on irreversible hydrocolloid impressions contaminated with Streptococcus sanguis or poliovirus. An irreversible hydrocolloid impression was made of a contaminated acrylic resin template. The impression was disinfected and residual microorganisms were harvested by sonication, cultured, and counted. The results showed that the impression material could act as a vehicle for the transfer of both bacteria and viruses. Further, the virus was shown to be present in the body of the impression and under certain conditions may evade decontamination.     

Surgical wafers: a comparative study

A comparative study of occlusal wafers for orthognathic surgery made for 185 orthognathic surgery patients with the mean age of 24.4+/-4.3 years is presented. This study is intended to highlight any wafer-associated surgical problems, which determine wafer design. Various types of occlusal wafers were used during the period of this review, but in most of the cases a simple quick-cure acrylic wafer was found to be most satisfactory. However, some difficult patients with cleft palates or neuromuscular disorders may require wafers of a novel design and material.