Sema Murat

Detection of vertical root fracture using cone-beam computerized tomography: an in vitro assessment

OBJECTIVES This study aimed to compare 2 cone-beam CT units [NewTom 3G (small FOV), Iluma (ultra/low resolution)] and an intraoral CCD sensor in the detection of vertical root fracture (VRF). STUDY DESIGN The VRFs were created in 30 teeth, and 30 intact teeth served as control samples. All images were evaluated twice by 4 observers. Kappa coefficients were calculated to assess intra- and interobserver agreement, and t tests were used to compare Az values (alpha = 0.05). RESULTS Both intra- and interobserver agreement values were higher for the ultra-resolution Iluma and NewTom 3G images compared with the low-resolution Iluma and intraoral CCD images. Az values for the ultra-resolution Iluma and NewTom 3G images were also higher than for the Iluma low-resolution and intraoral CCD images. No significant differences (P > .05) in diagnostic accuracy were found between the Iluma ultra-resolution and NewTom 3G images, with the exception of the second reading of observer 2 (P = .036), and no significant differences (P > .05) were found between the intraoral digital and low-resolution Iluma images. CONCLUSION Both ultra-resolution Iluma and NewTom 3G images performed better than low-resolution Iluma and intraoral CCD images in the detection of VRF.

Occlusal caries detection by using a cone-beam CT with different voxel resolutions and a digital intraoral sensor

OBJECTIVES This study assessed in vitro the diagnostic ability of intraoral digital CCD sensor images and CBCT images at different voxel resolutions in the detection of occlusal caries. STUDY DESIGN The study sample consisted of 130 mandibular molars (61 sound and 69 diseased). Digital intraoral images and CBCT images were obtained at 0.1-mm, 0.2-mm, and 0.3-mm voxel sizes. All images were evaluated separately by 4 observers, and evaluations were repeated after a 4-week interval. Weighted kappa coefficients were calculated to assess intra- and interobserver agreement for each image set, and scores were compared with the histological gold. For the estimation of nonparametric imaging modality effects and tests of hypotheses, SAS 9.0 and SAS macros were used for F1_LD_F1 factorial design. An a priori level of significance of P equals .05 was used. RESULTS High intra- and interobserver agreements were obtained (Kappa value range: 0.825 to 0.948 for intraobserver agreement and 0.700 to 0.903 for interobserver agreement). Estimated relative treatment effects (RTE) ranged from 0.26 to 0.85, which varied with caries level and imaging modality. Differences between RTE values obtained with ultra-resolution and high- and low-resolution images were not statistically significant for all caries levels. Comparing 3D and intraoral imaging modalities among caries levels showed that imaging modality performance was different for deep enamel, superficial dentine, and deep dentine; however, imaging modality performance was not statistically different for healthy and superficial enamel caries groups. CONCLUSION At all voxel sizes, CBCT images can be considered a tool for use in the diagnosis of occlusal caries.

The effects of digital image enhancement on the detection of vertical root fracture

AIM To determine the effects of digital image enhancement on observer ability to detect experimentally induced vertical root fractures (VRF). MATERIAL AND METHODS A total of 64 extracted human mandibular premolar teeth were used in this study. In 32 teeth, VRFs were created in the bucco-lingual planes by gently tapping with screw-type root-canal pins. The remaining 32 intact teeth served as a control group. Digital images were obtained using a charge coupled device sensor. Three observers separately examined the original and four types of digitally enhanced images (enhanced using sharpness, zoom-in, reverse-contrast, and pseudo-3D functions) at 1-week intervals. All teeth were evaluated using a 5-point scale for the presence/absence of VRF. Evaluations of each image set were repeated 1 month after the initial viewings. Kappa coefficients were calculated to investigate the degree of intra- and inter-observer agreement. The areas under the receiver operating characteristic (ROC) curves (Az values) were calculated using the MedCalc statistical software. ROC values for each image type, observer and viewing were compared using t-tests. A level of alpha = 0.05 was considered significant. RESULTS Kappa coefficients for intra-observer agreement ranged from 0.304 to 0.679. Inter-observer agreement kappa values ranged from 0.109 to 0.399 for the first reading and from 0.106 to 0.380 for the second reading. Statistical comparisons between Az values for each observer showed no significant differences (P > 0.05) among image types. CONCLUSION There were no differences in diagnostic outcomes among differently enhanced images in the in vitro detection of VRF.

Nerve damage assessment following implant placement in human cadaver jaws: an ex vivo comparative study.

The present study compared the use of cone beam computerized tomography (CBCT) images and intra-oral radiographs in the placement of final implant drills in terms of nerve damage to cadaver mandibles. Twelve cadaver hemimandibles obtained from 6 cadavers were used. Right hemimandibles were imaged using peri-apical radiography and left hemimandibles using CBCT, and the images obtained were used in treatment planning for the placement of implant drills (22 for each modality, for a total of 44 final drills). Specimens were dissected, and the distances between the apex of the final implant drill and the inferior alveolar neurovascular bundle and incisive nerve were measured using a digital calliper. Nerves were assessed as damaged or not damaged, and the Chi-square test was used to compare nerve damage between modalities (P < 0.05). Nerve damage occurred with 7 final drills placed based on peri-apical radiography (31.8%) and 1 final drill placed using CBCT images (4.5%). The difference in nerve damage between imaging modalities was statistically significant (P = 0.023), with CBCT outperforming intraoral film in the placement of final implant drills ex vivo. In order to prevent nerve damage, CBCT is recommended as the principal imaging modality for pre-implant assessment.

Comparison of Flexural Strength of Different CAD/CAM PMMA-Based Polymers: Comparison of Flexural Strength of Interim Resin Materials

PURPOSE To compare the flexural strength of different computer-aided design/computer-aided manufacturing (CAD/CAM) poly(methyl methacrylate)-based (PMMA) polymers and conventional interim resin materials after thermocycling. MATERIALS AND METHODS Rectangular-shaped specimens (n = 15, for each material) (25 × 2 × 2 mm3 ) were fabricated from 3 CAD/CAM PMMA-based polymers (Telio CAD [T]; M-PM-Disc [M]; Polident-PMMA [P]), 1 bis-acrylate composite resin (Protemp 4 [PT]), and 1 conventional PMMA (ArtConcept Artegral Dentine [C]) according to ISO 10477:2004 Standards (Dentistry-Polymer-Based Crown and Bridge Materials). The specimens were subjected to 10,000 thermocycles (5 to 55°C). Three-point flexural strength of the specimens was tested in a universal testing machine at a 1.0 mm/min crosshead speed, and the flexural strength data (σ) were calculated (MPa). The flexural strength values were statistically analyzed using 1-way ANOVA, and Tukey HSD post-hoc test for multiple comparisons (α = 0.05). RESULTS Flexural strength values ranged between 66.1 ± 13.1 and 131.9 ± 19.8 MPa. There were significant differences among the flexural strengths of tested materials, except for between T and P CAD/CAM PMMA-based polymers (p > 0.05). CAD/CAM PMMA-based polymer M had the highest flexural strength and conventional PMMA had the lowest (p < 0.05). CAD/CAM PMMA-based T and P polymers had significantly higher flexural strength than the bis-acrylate composite resin (p < 0.05), and conventional PMMA (p < 0.0001), and significantly lower flexural strength compared to CAD/CAM PMMA-based M (p < 0.05). CONCLUSIONS The flexural strength of CAD/CAM PMMA-based polymers was greater than the flexural strength of bis-acrylate composite resin, which had a greater flexural strength compared to conventional PMMA resin.

Accuracy of a Newly Developed Cone-Beam Computerized Tomography-Aided Surgical Guidance System for Dental Implant Placement: An Ex Vivo Study

The aim of the present study was to measure the accuracy of the cone-beam computerized tomography (CBCT)- aided StentCad Beyond surgical guidance system and to compare bone-supported and tooth/bone-supported guidance by using this system in dental implant placement ex vivo. Five cadaver mandibles were scanned using an Iluma CBCT scanner. After scanning, DICOM slices were transferred to the StentCad Beyond implant simulation software, which was used for preoperative implant planning. Using the StentCad Beyond guidance system, 9 implant drills were inserted using a bone-supported guidance system and 11 using a tooth/bone-supported guidance system. Mandibles were scanned again and these data were transferred to the StentCad Beyond software. Pre- and postoperative information was superimposed using the Rhinoceros version 4 software program, and deviations between planned and actual drill positions were calculated for each implant. In addition, differences between bone-supported and tooth/bone-supported guidance systems were analyzed by t-test, with a significance level of P < .05. Data analysis found a mean coronal deviation of 1.2 ± 0.3 mm and 0.6 ± 0.6 mm, mean apical deviation of 1.3 ± 0.6 mm and 0.7 ± 0.6 mm, mean apical and coronal depth deviation of 1.4 ± 0.3 mm and 1.3 ± 0.3 mm, and mean angular deviation of 4.2° ± 2.0° and 3.0° ± 1.5° for tooth/bone supported and bone-supported guides, respectively. No statistical differences were found in depth or angular deviations between groups (P > .05); however, statistically significant differences between groups were found in mean horizontal coronal deviation (P = .016) and mean horizontal apical deviation (P = .047). The StentCad Beyond system was found to be a reliable guide for placing implants ex vivo.

Prosthetic Rehabilitation of a Patient With Bilateral Cleft Lip and Palate Using Osseointegrated Implants and Extracoronal Resilient Attachments: A Case Report

This case study reports on the prosthetic rehabilitation of a patient with an unrepaired bilateral cleft lip and palate using osseointegrated implants, extracoronal resilient attachments, a combination of metal-ceramic cement-retained fixed partial restorations, and removable prosthesis. Preoperative clinical examination of a 32-year-old woman with bilateral cleft lip and palate revealed a large oronasal communication, hyperplastic soft tissue surrounding the hard palate defect, and a severely resorbed alveolar ridge. A maxillary obturator prosthesis supported by implants and retained with an extracoronal resilient attachment was designed to cover the oronasal communication in the hard palate and fulfill the patients functional and aesthetic requirements. The patient has been wearing the prosthesis for 1 year. Her speech quality has greatly improved, and her aesthetic and functional expectations have been met.

CBCT Imaging of Sinonasal Disease

In dental and maxillofacial cone beam computed tomographic (CBCT) imaging of the mid-facial region, it is highly likely that clinicians will observe various radiologic findings involving the paranasal sinuses. Dentists using CBCT are responsible for interpreting not only the radiologic findings needed for a specific dental task (e.g., implant treatment planning, detect periapical pathologies of posterior teeth in the maxilla) but also the structures, anatomic variability, and common diseases associated with the maxillary sinus. The purpose of this Chapter is to describe specific radiologic patterns indicative of sinonasal pathology, recommend CBCT specific imaging and display protocols, and provide guidelines for systematic interpretation of the paranasal sinuses on CBCT.

Anatomy of the Nose and Paranasal Sinuses

Depending on the protocol used, some or all of the paranasal sinuses may be visible within the imaging field-of-view when CBCT is used for dental purposes. Correct interpretation therefore necessitates a knowledge of paranasal sinus anatomy and an understanding of the clinical significance of anatomical variants and pathologies (see Chap. 29).

In Vitro Evaluation of Adhesion of Candida albicans on CAD/CAM PMMA-Based Polymers: Adhesion of C. albicans on CAD/CAM PMMA-Based Polymers

PURPOSE To compare the amount of adherent Candida albicans to different CAD/CAM poly(methyl methacrylate) (PMMA)-based polymers and conventional heat-polymerized PMMA after long-term thermal cycling. MATERIALS AND METHODS The specimens were subjected to 10,000 thermal cycles (5-55°C) and divided into two groups, uncoated and pellicle-coated. Surface roughness and contact angles of the specimens were measured. The surface morphology was observed with scanning electron microscopy (SEM). An adhesion test was performed by incubating the disk specimens in C. albicans suspensions at 37°C for 2 hours, and the adherent cells were counted under an optical microscope. The data were analyzed statistically using a variance analysis and Tukey HSD post hoc comparison test. The correlation between measurements was tested using a Pearson correlation analysis (α = 0.05). RESULTS CAD/CAM polymers generally showed statistically significant lowest Ra and contact angle values, whereas conventional PMMA showed the highest Ra and contact angle values in the uncoated group (p < 0.05). Pellicle coating essentially increased contact angle of all materials and reduced the differences in a number of Candida cells on the materials (p < 0.05). Candida adhesion was statistically significantly greatest on conventional PMMA when compared to CAD/CAM polymers. A strong positive correlation was found between the surface roughness of the specimens (p < 0.05) and the amount of adhered cells, whereas no correlation was found between hydrophobicity of the specimens and the amount of adhered cells (p > 0.05). CONCLUSIONS CAD/CAM PMMA-based polymers may be preferable to reduce Candida-associated denture stomatitis in long-term use.