Euiseong Kim

Prospective Clinical Study Evaluating Endodontic Microsurgery Outcomes for Cases with Lesions of Endodontic Origin Compared with Cases with Lesions of Combined Periodontal–Endodontic Origin

The aim of this study was to evaluate the outcomes of endodontic microsurgery by comparing the healing success of cases having a lesion of endodontic origin compared with cases having a lesion of combined endodontic-periodontal origin. Data were collected from patients in the Department of Conservative Dentistry, Dental College, Yonsei University, Seoul, Korea between March 2001 and June 2005. A total number of 263 teeth from 227 patients requiring periradicular surgery were included in this study. Patients were recalled every 6 months for 2 years and every year thereafter to assess clinical and radiographic signs of healing. A recall rate of 73% (192 of 263 patients) was obtained. The successful outcome for isolated endodontic lesions was 95.2%. In endodontic-periodontal combined lesions, successful outcome was 77.5%, suggesting that lesion type (ABC vs DEF) had a strong effect on tissue and bone healing.

Prognostic factors for clinical outcomes in endodontic microsurgery: a retrospective study.

INTRODUCTION This retrospective study examined the potential prognostic factors on the outcome after endodontic microsurgery and compared the predictors of isolated endodontic lesion with those of both isolated endodontic lesions and endodontic-periodontal lesions. METHODS The data were collected from patients with a history of endodontic microsurgery performed between August 2004 and December 2008 and at least 1 year before being evaluated. Surgical procedures were performed by the endodontic faculty and residents. After surgery, an operation record form was made with the preoperative, intraoperative, and postoperative factors from the clinical and radiographic measures. For statistical analysis of the predisposing factors, the dependent variable was the dichotomous outcome (ie, success vs failure). RESULTS Of 907 cases, 491 were retained at follow-up. At the 0.05 level of significance, age, sex (female), tooth position (anterior), root-filling length (inadequate), [corrected] lesion type (endodontic lesion), root-end filling material (mineral trioxide aggregate and Super EBA; Harry J. Bosworth, Skokie, IL), and restoration at follow-up appeared to have a positive effect on the outcome. On the other hand, with an isolated endodontic lesion, the tooth position (anterior), root-filling length (inadequate), [corrected] and restoration at follow-up were significant factors at the 95% confidence level. CONCLUSIONS Under the control of the significant variables in logistic regression, the potential prognostic factors on the outcome were sex, tooth position, lesion type, and root-end filling material. On the other hand, the tooth position was a pure predictor of an endodontic lesion affecting the clinical outcome.

Computed Tomography as a Diagnostic Aid for Extracanal Invasive Resorption

A case of multiple extracanal invasive resorption is reported. The patient had a history of hypothyroidism for approximately 1 yr before the dental visit. Utilization of computed tomography and a rapid prototyping tooth model in diagnosing the exact location and the size of the resorption area are discussed.

Outcomes of Endodontic Micro-resurgery: A Prospective Clinical Study

INTRODUCTION This study examined the outcomes of endodontic resurgery by using current microsurgery techniques on failed teeth with previous endodontic surgery. Another goal was to determine any significant outcome predictors of endodontic surgery by determining the causes of failure in the first endodontic surgery. METHODS The data were collected from patients in the Department of Conservative Dentistry at the Dental College, Yonsei University in Seoul, Korea between March 2001 and May 2009. All 54 teeth that required surgical retreatment were included in this study. All surgical procedures were performed by using an operating microscope and biocompatible root-end filling materials such as mineral trioxide aggregate (MTA) or Super EBA. The patients were recalled every 6 months for 2 years and every year thereafter to assess the clinical and radiographic signs of healing. RESULTS The recall rate was 77.8% (42 of 54 patients). Of the 42 cases recalled, 39 cases were included in the success category, giving an overall success rate of 92.9%. The most common possible causes of failure were no root-end filling and incorrect root-end preparation. CONCLUSIONS The use of microsurgical techniques and biocompatible materials such as MTA and Super-EBA resulted in a high clinical success rate, even in endodontic resurgery.

An in vivo comparison of working length determination by only root-ZX apex locator versus combining root-ZX apex locator with radiographs using a new impression technique

OBJECTIVE The objective of this study was to compare, in vivo, the accuracy of working length determination using only the Root-ZX electronic apex locator versus adjusting Root-ZX measurements after obtaining a working length radiograph. STUDY DESIGN The working length was determined in 25 premolar root canals using Root-ZX and K-files were fixed at these positions. Radiographs were acquired and interpreted, and the recorded working length measurement was adjusted, if necessary, for a combined measurement. The teeth were then extracted in an effort to determine the position of the file tip to the root canal constriction. On the basis of the position of the file tip to the apical foramen, polyvinylsiloxane impressions of the root apex were taken, or the root was imbedded in acrylic resin and ground in order to measure the position of the file tip to the apical constriction. RESULTS The Root-ZX alone detected the apical constriction within +/- 0.5 mm in 84% of the samples (21 of 25 canals). However, 96% (24 of 25 canals) were within this range when the combination of Root-ZX and radiographs was used. We noted no statistical significance between these 2 methods (P > .05). CONCLUSION Using a Root ZX Electronic Apex Locator combined with radiographs is recommended for the determination of working length, although there was no statistical significance between those 2 groups in this study.

Comparison of the cleaning efficacy of a new apical negative pressure irrigating system with conventional irrigation needles in the root canals

OBJECTIVES This study evaluated the efficacy of EndoVac system in comparison with that of a conventional needle irrigation method when the root canals were enlarged to various sizes. STUDY DESIGN Sixty-nine single-rooted teeth were divided into 3 groups according to the root canal irrigation system (24G and 30G needle and EndoVac). Each group was divided into 3 subgroups according to the MAF size (#25, #40, and #60). Four-micron-thick serial sections were prepared at 1.5 and 3.5 mm from the apical level and photographs were taken for the analysis. The influence of the irrigation system and apical size was evaluated using a 1-way ANOVA test and Tukeys test (P < .05). RESULTS At both levels, significant differences were detected between EndoVac system and conventional needle irrigation in removing debris (P < .05). The relationship between the MAF size and irrigation efficacy was found to have a positive relationship (P < .05). CONCLUSIONS EndoVac left significantly less debris behind than the conventional needle irrigation methods. Although all 3 irrigation methods resulted in clean root canals because the percentage occupied by remaining debris was very low in our specimens, larger apical instrumentation seemed to improve apical root canal debridement.

Analysis of the cause of failure in nonsurgical endodontic treatment by microscopic inspection during endodontic microsurgery.

INTRODUCTION This study examined the clinical causes of failure and the limitation of a previous endodontic treatment by an inspection of the root apex and resected root surface at 26× magnification during endodontic microsurgery. METHODS The data were collected from patients in the Department of Conservative Dentistry at the Dental College, Yonsei University in Seoul, Korea between March 2001 and January 2011. All root-filled cases with symptomatic or asymptomatic apical periodontitis were enrolled in this study. All surgical procedures were performed by using an operating microscope. The surface of the apical root to be resected or the resected root surface after methylene blue staining was examined during the surgical procedure and recorded carefully with 26× magnification to determine the state of the previous endodontic treatment by using an operating microscope. RESULTS Among the 557 cases with periapical surgery, 493 teeth were included in this study. With the exclusion of unknown cases, the most common possible cause of failure was perceived leakage around the canal filling material (30.4%), followed by a missing canal (19.7%), underfilling (14.2%), anatomical complexity (8.7%), overfilling (3.0%), iatrogenic problems (2.8%), apical calculus (1.8%), and cracks (1.2%). The frequency of possible failure causes differed according to the tooth position (P < .001). CONCLUSIONS An appreciation of the root canal anatomy by using an operating microscope in nonsurgical endodontic treatment can make the prognosis more predictable and favorable.

Tooth Discoloration after the Use of New Pozzolan Cement (Endocem) and Mineral Trioxide Aggregate and the Effects of Internal Bleaching

INTRODUCTION The aim of this study was to evaluate tooth discoloration after the use of mineral trioxide aggregate (MTA) and to examine the effect of internal bleaching on discoloration associated with MTA. METHODS Thirty-two teeth were endodontically treated. Three-millimeter plugs of MTA, ProRoot, Angelus, or Endocem were placed on the access cavities of 24 teeth. Eight teeth served as the control group. After 24 hours, the access cavities were restored, and the tooth color was recorded at baseline and at 1, 2, 4, 8, and 12 weeks. After 12 weeks, the MTA materials were removed under a microscope, and an internal bleaching treatment was performed. After removal of the MTA materials and after a 1-week bleaching treatment, the color changes were measured, and the MTA-dentin interfaces were observed under a microscope. RESULTS The ProRoot and Angelus groups displayed increasing discoloration during a period of 12 weeks. The discoloration associated with ProRoot and Angelus was observed at the MTA-dentin interface and on the interior surface of the dentin. However, the Endocem groups demonstrated no significant discoloration (P < .05). No marginal discoloration was observed around the material in the Endocem group. Removal of the discolored MTA was effective for resolving the discoloration in all of the experimental groups (P < .05). However, a subsequent internal bleaching treatment was not significantly effective compared with the removal of MTA. CONCLUSIONS ProRoot and Angelus caused tooth discoloration. However, Endocem did not affect the contacting dentin surface. Removing the discolored MTA materials contributed more to resolving the tooth discoloration than post-treatment internal bleaching.

Long-term Outcome of the Cases Classified as Successes Based on Short-term Follow-up in Endodontic Microsurgery

INTRODUCTION In a previous study, we evaluated the outcomes of endodontic microsurgery by comparing the healing success of cases involving a lesion of endodontic origin with cases involving a lesion of combined endodontic-periodontal origin. Of the 188 teeth over the 5-year period, 172 (91.5%) were considered to be successes. The purpose of this study was to evaluate the outcomes, up to 10 years, of the cases that were classified as successes in the previous study. METHODS The 172 cases that were considered to have successful outcomes in the previous study were included. Patients were followed up every 6 months for 2 years and every year up to 10 years. On every follow-up visit, clinical and radiographic evaluations were performed according to the same criteria as in the original study by the same 2 examiners. RESULTS A follow-up rate of 60.5% (104/172 cases) was obtained. Of the 104 followed-up cases, 97 cases were included in the successful group, 91 with complete healing and 6 with incomplete healing. The overall maintained success rate was 93.3%. The failure group, which meant a reversal to disease, included 7 cases with unsatisfactory healing. CONCLUSIONS In this study, 93.3% of endodontic microsurgery cases that were considered healed in a prior 5-year study remained healed after more than 6 years.

Effect of EDTA on Attachment and Differentiation of Dental Pulp Stem Cells

INTRODUCTION In regenerative endodontics, it is believed that EDTA induces odontoblast differentiation by releasing growth factors from the dentin matrix. The aim of this study was to evaluate the effect of EDTA on the attachment and differentiation of dental pulp stem cells (DPSCs). We also investigated whether the behavioral changes of DPSCs could be caused by biochemical components released from EDTA-treated dentin. METHODS Cells were obtained from human third molars, and the stem-like nature of the cells was investigated by flow cytometric analysis. DPSCs were seeded on EDTA-treated and untreated dentin slices. After 3 days of culture, cell attachment was evaluated by cell density, fibronectin 1 gene expression level using quantitative real-time polymerase chain reaction, and scanning electron microscopy. After 21 days of culture, the expression of differentiation genes was investigated by quantitative real-time polymerase chain reaction, and calcification was observed using alizarin red S staining. To investigate the EDTA-induced growth factor release, DPSCs were cultured with or without direct contact with the EDTA-treated dentin surface. RESULTS After 3 days of culture, both the cell density and fibronectin expression level were significantly higher in the EDTA-treated dentin group. After 3 weeks, the DPSCs on the EDTA-treated dentin surfaces showed higher expression levels of dentin sialophosphoprotein and dentin matrix protein 1, whereas the DPSCs cultured without direct contact with the EDTA-treated dentin surfaces did not exhibit these findings. CONCLUSIONS Our results showed that EDTA induced cell attachment and odontoblastic/osteoblastic differentiation, which was observed only in the group in which the DPSCs were placed in direct contact with the EDTA-treated dentin surfaces. These findings suggest that EDTA is beneficial for achieving successful outcomes in regenerative endodontics.