The Journal of Japan Endodontic Association
Online ISSN : 2423-9429
Print ISSN : 1347-8672
ISSN-L : 1347-8672
Volume 28, Issue 3
Displaying 1-7 of 7 articles from this issue
Original Article
  • HIDA Yoshie, SUZUKI Noriyuki, YOSHIOKA Takatomo, SUDA Hideaki
    2007 Volume 28 Issue 3 Pages 131-136
    Published: 2007
    Released on J-STAGE: December 30, 2017
    JOURNAL FREE ACCESS

    Abstract : The purpose of this study was to evaluate the acceptability of endodontic treatment as a highly specialized dental care in Japan. One hundred and six patients answered a questionnaire about their awareness of endodontic treatment and its cost. Awareness of endodontic treatment was low, so it is necessary to disseminate correct informations on endodontic treatment. Endodontic treatment by specialists might be acceptable if its importance and high specialty were understood by patients.

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  • HORIBA Naoki, KITAMURA Naritaka, TORIMURA Toshiaki, YAMAGUCHI Masataka ...
    2007 Volume 28 Issue 3 Pages 137-142
    Published: 2007
    Released on J-STAGE: December 30, 2017
    JOURNAL FREE ACCESS

    Abstract : The purpose of this study was to evaluate the morphological change in root canal dentin and the suitability of carbon dioxide (CO2) laser irradiation for root canal obturation. Two pulse modes, pulse mode (40 pps) and super pulse mode (151 pps) were used. Under 4 W laser power, the CO2 laser was set to have a total energy of 32 J. The morphological changes in the root canal dentin were observed by using a scanning electron microscope. The effects on the apical sealing ability were examined by measuring the penetration distance of the dye.

     The following results were obtained :

     1. When the apical portion of the root canal was irradiated in either mode, no dentin loss or micro-cracks were found on the root canal dentin surfaces ; however, small globular structures and a wavy surface caused by the melting of dentin debris were found.

     2. As to the rate and distance of dye penetration from the apex, there was no statistically significant difference between the control (no laser irradiation) group and either mode group.

     3. Regarding the rate of extrusion of the root canal filling material from the apical foramen, there was no statistically significant difference between the control group and either irradiation mode group.

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  • YASUDA Yoshiyuki, OHTOMO Eiji, MAEDA Hidefumi, AKAMINE Akifumi, SAITO ...
    2007 Volume 28 Issue 3 Pages 143-148
    Published: 2007
    Released on J-STAGE: December 30, 2017
    JOURNAL FREE ACCESS

    Abstract : One-step adhesive resins have been widely used in restoration operations due to their simple procedure. However, the cytotoxicity of one-step adhesive resin is not fully understood. The purpose of this study was to investigate the effects of six one-step adhesive resins on cytotoxicity and differentiation to odontoblasts. Specimens from Absolute (AB), AQ Bond Plus (AQ), G-bond (GB), i-bond (IB), Adper Prompt L-Pop (APL) and Clearfil Tri-S Bond (S3) were eluted with fresh culture media for 24 hours. Human dental pulp cells and mouse odontoblast-like cells (MDPC-23) were cultured with extracts of the adhesive resins for 24 hours and cytotoxicity was judged by tetraxolium bromide reduction assay. AQ was the least toxic against both human dental pulp cells and MDPC-23 among the six one-step adhesive resins studied here. Furthermore, ALP activities in cell extracts of MDPC-23 cultured with each adhesive resin for 2, 4 and 6 days were measured to examine whether the resin affects the differentiation to odontoblasts. Only IB significantly inhibited ALP activity compared to control cells. In conclusion, AQ is the least toxic material to human dental pulp cells and MDPC-23 among the one-step adhesive resins examined in this study.

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  • KOMORI Norio, OGISO Bunnai
    2007 Volume 28 Issue 3 Pages 149-153
    Published: 2007
    Released on J-STAGE: December 30, 2017
    JOURNAL FREE ACCESS

    Abstract : This article shows the usefulness of dental micro CT in endodontic treatment.

     Case 1 : On clinical examination, the sinus tract was observed on the lingual mucosa of the right first incisor and the patient complained of slight discomfort of the gingiva.

     A dental radiograph was taken with a gutta-percha point inserted into the sinus, and it reached the periapical area of the right first incisor.

     However, the right first incisor showed pulp vitality using an electric pulp tester. From this result, we decided to perform endodontic treatment.

     One year later, we took a dental micro CT image, and a lateral branch was observed at the apical 1/3 of the lingual root surface and a periapical lesion was observed around the apex.

     Case 2 : The patient was referred to our clinic to receive an apicoectomy. The referring dentist diagnosed that operation was necessary because the periapical lesion was huge and the cortical bone was affected. However, we diagnosed this case as a contra-indication for apicoectomy.

     One year later after root canal filling, the size of the lesion had reduced as observed on the dental micro CT.

     From this finding, the size of the periapical lesion is not an important factor concerning healing of the periapical lesion.

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  • MIYASHIN Michiyo, EBASHI Miho
    2007 Volume 28 Issue 3 Pages 154-160
    Published: 2007
    Released on J-STAGE: December 30, 2017
    JOURNAL FREE ACCESS

    Abstract : The risk associated with developmental anomalies of crown is an early pulpal involvement. The purpose of the present study was to examine the effect and prognosis of preventive treatment of developmental anomalies of crown on immature permanent teeth.

     The subjects of this study were patients who visited the pediatric dental clinic of the Tokyo Medical and Dental University. The cases included 3 teeth from 3 patients aged 6 to 9 years at their initial visits.

     1. In the upper lateral incisor with dens invaginatus detected by X-ray prior to eruption, the surgical exposed pit and invaginated space were thoroughly debrided with endodontic files and filled with calcium hydroxide paste before being obturated with root canal cement and resin composite restoration. These treatments were successful to keep the pulp vital and to promote root development.

     2. In the upper first premolar with hypoplasia (Turner’s tooth) which was coated with cement and bonding resin after eruption, the pulp survived soundly and the root formation continued. This was administered with provisional restoration while the patients were children, then a partial crown was made with minimum crown preparation when they had become adults.

     3. In the upper first premolar with dens evaginatus, reinforcement with composite resin was performed after eruption. 2 years and 8 months later, total pulpitis was detected in this tooth. The risk associated with dens evaginatus is an early pulpal involvement after eruption.

     These findings may explain why earlier screening and intervention can prevent pulpal infection, pulpal inflammation and subsequent necrosis. It is suggested that X-ray examination is desirable prior to eruption of permanent teeth for the detection of developmental anomalies of crown. For normal future occlusion, appropriate provisional restoration and its management are necessary.

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  • ―Occlusal anomalous tubercles on lower premolars―
    KAWASAKI Kohichi, IGARASHI Masaru, MIYASATO Tsuyoshi, ARAI Kyoko, ARAI ...
    2007 Volume 28 Issue 3 Pages 161-171
    Published: 2007
    Released on J-STAGE: December 30, 2017
    JOURNAL FREE ACCESS

    Abstract : In the middle of the occlusal surface of human premolars, occasionally the so-called central cusps (dens evaginatus) have been noted. Because the occlusal anomalous tubercle can possess its own pulp chamber, pulpitis and its sequelae can result from fracture or splitting through mastication.

     The patient was a 9-year-old Japanese boy in good health who had non-vital incompletely formed funnel shape roots of the lower second premolars with unilateral buccal swelling and internal dental fistulae. The tubercles gave the teeth a volcanic appearance. Radiographs showed a large periapical rarefaction over the areas of these teeth. Clinical diagnosis of these teeth was chronic suppurative apical periodontitis associated with the abnormal cusps. The endodontic challenges were successfully treated by apexification of the immature involved teeth using FR-Ca paste.

     The occlusal anomalous tubercles were removed by the air turbine technique. These materials were fixed in 10% formalin solution. The decalcified sections of the tubercles were examined histopathologically. These cusps had slender pulp horns extending towards the pulps. In the pulp horn areas, pulp necrotic debris was seen. Displacement of cellular breakdown products was often seen within the dentinal tubules. Bacteria must have gained entrance to the pulp via the patent dentinal tubules.

     Endodontic treatment of two affected premolars was performed by isolation with a rubber dam and surface disinfection. Root canal debridement and preparation by large K-files or H-files were employed. Instrumentation was done carefully to slightly short of the radiographic apex using a circumferential filing motion under copious canal irrigation with 6% sodium hypochlorite following by 3% hydrogen peroxide alternately into the canal. The canals were dried with large sterile cotton rolled on a broach.

     FR-Ca paste was introduced with a Lentulo filler and a flat gutta-percha master cone, and also condensed with a large plugger.

     The presence of apical calcific barrier was examined with radiographs, touch by canal instruments, an electronic impedance meter (Komatsu) and a Canalscope® (Osada Electric Co).

     Apical calcific tissue replica was observed with a scanning electron microscope. An apical closure had apparently occurred from 6 months to 2 years later on the left premolar. The canal was obturated with gutta-percha using a lateral condensation technique. On the right premolar, apical healing has not progressed with a broader periapical pathosis after 6 years radiographically. There was an obvious reason for this failure : the canal space had not been thoroughly filled. Therefore this tooth was reopened, and the FR-Ca was washed out and repacked. Although FR-Ca paste extruded apically too much, there were no apparent long-term adverse effects. SEM photographs showed that even in the inner surface of the apical complete calcific barrier (hard tissue bridging) there were indentations, convexities, and other irregularities with the presence of small holes and coalescence structure.

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  • TAGUCHI Masahiro
    2007 Volume 28 Issue 3 Pages 172-177
    Published: 2007
    Released on J-STAGE: December 30, 2017
    JOURNAL FREE ACCESS

    Abstract : When the patient was primary school student, she fell down and hit her face hard.

     Her mesial angle of right maxillary anterior teeth was broken and her lips were injured. Based on pulp vital tests, results, and immature permanent teeth, I decided long-term observation was necessary.

     2 years and 3 months later, the apex of the teeth was completed, but there was inflammation at the periapical region, so I started endodontic treatment.

     16 years after endodontic treatment was done, the teeth had changed color to dark brown, so I bleached the teeth.

     I will report further observations at 18 years.

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