CBCT-based Diagnosis of Periapical Lesion of Maxillary First Premolar Mimicking That of Second Premolar.

Apical periodontitis is usually diagnosed based on clinical findings and dental X-rays. Recently, however, dental cone beam computed tomography (CBCT), which provides 3-D images of the maxillofacial region, has enabled dentists to examine patients undergoing endodontic therapy more effectively, improving diagnostic accuracy. Here, we describe a positive treatment outcome achieved using CBCT to diagnose apical periodontitis of the maxillary premolars, which had proven difficult to diagnose based on clinical findings and dental radiography alone. The patient was a 42-year-old Japanese man who presented with the chief complaint of gingival swelling in the maxillary right premolar region. Our initial diagnosis, based on clinical findings and dental X-ray, was apical periodontitis of the maxillary right second premolar, and treatment was started. However, after the patient failed to respond to the treatment, CBCT was performed. Based on these new findings, the diagnosis was changed to one of apical periodontitis of the upper right first premolar, and the patient was treated accordingly. Previous studies have described the complex anatomical morphology of the upper premolars, noting multiple roots and variation in the morphology of the root canals. The 3-D images provided by dental CBCT allow better assessment of oral conditions than the traditional 2-D images provided by dental X-rays, which in turn enables the dentist to better select the most appropriate treatment. Here, the patient showed no symptoms and was progressing well at a 6-month follow-up visit. The present results indicate that when clinical findings and dental X-rays alone are insufficient to allow a secure diagnosis, CBCT offers an effective alternative which will enable the appropriate treatment to be selected more reliably.

Microscopic Endodontics in Infected Root Canal with Calcified Structure: A Case Report.

Calcium deposited within a root canal due to exogenous stimuli may hamper root canal treatment. In endodontic treatment, an operating microscope allows the conditions within the root canal to be directly viewed and evaluated. This report describes a case in which an operating microscope was used to facilitate the excision of a calcified structure from within a root canal at an early stage in the treatment of an infection. An 18-year-old man was referred to our clinic due to suspected chronic suppurative apical periodontitis of the right maxillary central incisor. Periapical radiography confirmed the presence of a radioopaque structure inside the root canal that was likely to pose an obstacle to endodontic treatment. After opening the pulp chamber, an operating microscope was used to directly confirm the presence of the calcified structure in the root canal, which was removed using an ultrasonic tip. The infected root canal was treated using calcium hydroxide. Two months later, closure of the apical foramen as a result of calcification of the apical foramen was confirmed and the root canal filled. Using an operating microscope to directly view a structure posing an obstacle to root canal treatment made it possible to perform an excision while avoiding risks such as canal perforation.

An endodontic-periodontal lesion with primary periodontal disease: a case report on its bacterial profile.

The microflora in the periodontal pockets can affect the dental pulp and cause endodontic-periodontal lesions or retrograde pulpitis. Here we report an endodontic-periodontal lesion together with its bacterial profile. The lesion occurred in the maxillary right first molar of a 40-year-old woman who presented at our hospital complaining of a violent toothache since the previous night. Clinically, the tooth was caries-free and an electric pulp test showed it to be vital. The tooth showed signs of advanced periodontitis and the periodontal pocket was deep, reaching the apex of the palatal root. The clinical diagnosis was an endodontic-periodontal lesion with primary periodontal disease. Subsequent endodontic treatment comprised pulp extirpation and root canal filling, followed by periodontal treatment consisting of scaling and root planing. The tooth was finally restored with a full metal crown. No further signs of periodontal disease or periapical lesions have been observed to date. Bacteria were sampled from the root canal and periodontal pocket for a microbiological assessment using 16S rRNA gene-based PCR. Microbiologically, the profile of the bacterial species from the palatal root canal was similar to that from the periodontal pocket of the palatal root. Porphyromonas gingivalis, Fusobacterium nucleatum and Eikenella corrodens were detected in both samples. The occurrence of bacteria common to both sites in this patient further supports the proposition that periodontal disease is the definitive source of root canal infections. The present results suggest that a bacterial examination would be helpful in confirming and supporting the clinical diagnosis in such lesions.

Laser welding method for removal of instruments debris from root canals.

The purpose of this study was to clarify the viability of a novel method for removing debris from broken instruments from root canals using a laser apparatus. Laser welding was performed on stainless steel or nickel titanium files using an Nd:YAG laser. Retention force between the files and extractors was measured. Increase in temperature on the root surface during laser irradiation was recorded and the irradiated areas evaluated with a scanning electron microscope. Retention force on stainless steel was significantly greater than that on nickel titanium. The maximum temperature increase was 4.1°C. The temperature increase on the root surface was greater in the vicinity of the welded area than that at the apical area. Scanning electron microscopy revealed that the files and extractors were welded together. These results indicate that the laser welding method is effective in removing debris from broken instruments from root canals.

Digital video image processing from dental operating microscope in endodontic treatment.

Recently, optical microscopes have been used in endodontic treatment, as they offer advantages in terms of magnification, illumination, and documentation. Documentation is particularly important in presenting images to patients, and can take the form of both still images and motion video. Although high-quality still images can be obtained using a 35-mm film or CCD camera, the quality of still images produced by a video camera is significantly lower. The purpose of this study was to determine the potential of RegiStax in obtaining high-quality still images from a continuous video stream from an optical microscope. Video was captured continuously and sections with the highest luminosity chosen for frame alignment and stacking using the RegiStax program. The resulting stacked images were subjected to wavelet transformation. The results indicate that high-quality images with a large depth of field could be obtained using this method.

Evaluation of wear and subsequent dye penetration of endodontic temporary restorative materials.

This study evaluated the wear resistance and sealing property of endodontic temporary restoratives by means of functional stressing using a wear simulator. The pulp chamber of 28 extracted molars was opened and filled with cotton, and then the cavity was filled with a temporary material--Caviton, Temporary Pack, Neodyne-alpha, or TERM. Specimens were subjected to a wear test, and data for wear and dye penetration were analyzed by one-way ANOVA independently (p < 0.05). Wear values of Neodyne-alpha (0.09 +/- 0.05 mm) and TERM (0.24 +/- 0.06 mm) were significantly less than those of Caviton (1.79 +/- 0.15 mm) and Temporary Pack (1.02 +/- 0.40 mm). In terms of dye penetration, Neodyne-a leaked significantly less than the other materials at 0.40 +/- 0.32 mm. On the other hand, there were no significant differences between TERM (1.30 +/- 0.57 mm) and Temporary Pack (2.10 +/- 0.12 mm), and between Caviton (2.60 +/- 0.41 mm) and Temporary Pack.