The efficacy of ultrasound in removing cast metal posts was evaluated in this in vitro study using one or two ultrasound units and ultrasonic vibration for various lengths of time. The crowns of 30 healthy maxillary canines were removed, the roots were embedded in acrylic resin blocks, and the root canals were treated endodontically. The canals were prepared and their impressions were taken with self-curing acrylic resin. After casting with copper-aluminum alloy, the posts were blasted with aluminum oxide and cemented with Panavia F resin cement. The specimens were divided into five groups. In groups I and II, only one ultrasound unit was used for 30 and 60 s, respectively; in groups III and IV, two ultrasound units were used simultaneously for 30 and 60 s, respectively; in group V, ultrasound was not used (control). Ultrasonic vibrations were applied with an Enac OE-5 ultrasound unit and an ST-09 tip. All samples were subjected to traction on an Instron machine (model 4444) at a cross-head speed of 1 mm/min. Analysis of the results revealed a statistically significant difference between the groups (ANOVA, P < 0.01); however the difference between groups II and IV was not statistically significant. The efficacy of ultrasound in removing intraradicular posts was confirmed, and the most effective technique was the use of two ultrasound units, independent of the length of time ultrasound was applied. (J. Oral Sci. 47, 117-121, 2005)
A radiographic study was conducted to investigate the relationship between the technical quality of coronoradicular posts and periapical status. A total of 400 periapical radiographs, including 560 posts, of patients attending the Dental Department at Jordan University Hospital were scanned and studied. It was found that maxillary teeth were more frequently restored with posts (65.36%) than mandibular teeth (34.64%). Tapered posts accounted for 73.93% of the posts used. The ratio of the mean post length to crown length was 0.8, and that to root length was 0.45. The mean length of the remaining gutta percha apical to the end of the post was 6.22 mm. In addition, 25% of the posts deviated from the line of the root canal. Periapical radiolucency was evident in 53.93% of the assessed teeth. It is concluded that inadequate root canal treatment and coronoradicular posts are associated with increased prevalence of periapical radiolucency, and that general dental practitioners should be better trained in performing endodontic treatment and restoring endodontically treated teeth.(J. Oral Sci. 47, 123-128, 2005)
The purpose of this study was to quantitatively evaluate the axial wall taper of prepared artificial teeth using a non-contact three-dimensional shape measuring system. A total of 54 artificial teeth prepared by pre-clinical dental students for complete cast restorations were evaluated. For quantitative analysis, five cross sections were computer-graphically placed perpendicularly to the z-axis. The surface coordinate values (x, y, z) of each cross section were converted into polar coordinate values (r, θ), which were then graphically rendered to a two-dimensional plane. At four points, each 90° from the distal center point of the cross section, the axial wall taper was quantitatively calculated using a formula based on the differences in radius between the highest and lowest positions of the cross sections of the prepared tooth. The average calculated taper was 5.8° in the distal region, 21.7° in the buccal region, 14.9° in the mesial region and 12.5° in the lingual region. These results suggest that the axial wall taper of prepared teeth can be quantitatively evaluated using this measuring system. (J. Oral Sci. 47, 129-133, 2005)
The aim of the present study was to assess the response of rat dental pulp to direct pulp capping with propolis. Flavonoid and non-flavonoid materials were purified from an ethanol extract of propolis obtained from South Sulawesi, Indonesia. A Class I cavity was prepared on the occlusal surface of the right maxillary first molar in Sprague Dawley rats. The dental pulp was exposed and then capped with a zinc oxide-based filler as a control (group I), or with propolis flavonoids (group II) or non-flavonoids (group III). The animals were sacrificed at week 1, 2 or 4, biopsy samples were obtained, and these were stained and viewed by light microscopy. The results showed that pulp inflammation occurred in groups I and III as early as week 1. No dentin bridge formation was seen in these groups. In contrast, there was no evident inflammatory response in group II at week 1. Mild and moderate pulp inflammation in this group occurred at 2 and 4 weeks after treatment, respectively. Partial dentinal bridge formation was seen in group II at week 4. Therefore, the present results suggest that direct pulp capping with propolis flavonoids in rats may delay dental pulp inflammation and stimulate reparative dentin. (J. Oral Sci. 47, 135-138, 2005)
This clinical report describes a treatment for the replacement of a missing mandibular anterior tooth using a cantilever single-retainer resin-bonded fixed partial denture (RBFPD), fabricated from zirconium dioxide (ZrO2) ceramic. No clinical complications were observed at the 2-year 6-month follow-up examination after placement of the ZrO2 ceramic RBFPD, and satisfactory functional and esthetic results were achieved. A treatment modality using a cantilever ZrO2 ceramic RBFPD is an alternative for single anterior tooth replacement. Further clinical studies are required to evaluate the long-term potential of cantilever single-retainer ZrO2 ceramic RBFPDs. (J. Oral Sci. 47, 139-142, 2005)
Here, we report the management of a type I endoperiodontal lesion with furcation bone loss. A 59-year-old female attended our hospital with the chief complaint of mobility of tooth 46 and recurrent gingival swelling around the tooth. She previously received dental treatment from two dentists, but her condition did not improve. The tooth manifested the symptoms of typical periodontitis, such as gingival swelling, tooth mobility, pus discharge from the periodontal pocket and furcation bone loss. The tooth had no caries and the pulp reacted to an electric pulp test. Careful examination of the gingiva revealed traces of dental fistula. X-ray examination via a gutta percha inserted into the fistula revealed that furcation bone loss was associated with the periapical lesion. We diagnosed a type I endoperiodontal lesion, and applied Periocheck, a detection kit for peptidase-producing bacteria, to check for decreases in bacteria in the furcation and root canals. Soon after non-surgical root canal treatment, the condition of tooth 46 improved without periodontal treatment. After confirming a negative score with Periocheck, the root canal was filled. After 3 months, the furcation bone loss was on the way to recovery. These results indicate that proper diagnosis and confirmation of a decrease in root canal bacteria are important for treating endoperiodontal lesions. (J. Oral Sci. 47, 143-147, 2005)
Intra-osseous fibromas of the jaw are classified by origin. Intra-osseous odontogenic fibromas have odontogenic epithelia, while desmoplastic fibromas do not. However, it is often difficult to determine the odontogenic origin for central fibromas. Three subjects with a diagnosis of intra-osseous fibroma were examined. Case 1 was a 35-year-old man found to have a panoramic radiograph from the right premolar to the mandibular ramus in the mandible that exhibited multilocular radiolucency. Within the radiolucency, small-radioopaque bodies were observed. Case 2 was a 13-year-old female, in whom a panoramic radiograph from the left premolar to the molar in the mandible showed multilocular radiolucency. Case 3 was a 51-year-old female who exhibited a heart-shaped radiolucency in the panoramic radiograph of the left first molar area in the mandible. We also reviewed the literature for previously reported cases of intra-osseous odontogenic and desmoplastic fibroma. In 64 cases of intra-osseous odontogenic fibroma and 68 cases of desmoplastic fibroma we extracted data on age, sex, location, and radiographic findings. Based on the analysis of the reported literature cases, re-evaluation of the patients in our study revealed that case 1 could be classified as desmoplastic fibroma, while cases 2 and 3 were intra-osseous odontogenic fibromas. (J. Oral Sci. 47, 149-157, 2005)
Sex hormones are believed to be a risk factor for periodontitis because of their ability to proliferate specific periodontal microorganisms and affect host immunologic response. In this case report, gingival redness and swelling occurred during the menstrual cycle, although the patient maintained good oral hygiene during periodontal treatment. Medical history revealed that exacerbation of gingival infla-mmation corresponded to the menstrual cycle and occurred during the ovulation period, when estrogen levels are high. Mean bleeding index of the ovulation period (18.9%) showed higher levels than that during the menstrual phase (5.3%). This case indicates that frequent and effective maintenance should be provided while considering the influence of the menstrual cycle, as sex hormones may be involved in exacerbating gingival inflammation. (J. Oral Sci. 47, 159-164, 2005)
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