• Journal of the korean academy of Pediatric Dentistry
• /
• v.36 no.2
• /
• pp.288-292
• /
• 2009

A crown-root fracture is defined as a fracture involving enamel, dentin, and cementum. The fractures may be grouped according to pulpal involvement into uncomplicated and complicated. Generally a vertically crown-root fractured tooth must be extracted. However, it should be mentioned that the cases have been reported where bonding of the coronal fragment has led to consolidation of the intraalveolar part of the fracture. Definitive conservative therapy comprises one of four treatment alternatives; fragment removal only, fragment removal with gingivectomy, orthodontic extrusion of apical fragment, and surgical extrusion of apical fragment. The choice is primarily determined by the exact information on the site and the type of fracture, but the cost and the complexity of treatment can also be decisional factors. On the other hand, intentional replantation of the teeth with vertical root facture reconstructed with resin bonding has emerged as a new promising method in recent years. This case presents an intentional replantation of the crown-root fractured maxillary central incisor reconstructed with resin bonding. However, an obvious increase of radiolucency was observed after 4 months and the tooth was re-fractured after 16 months.

• Restorative Dentistry and Endodontics
• /
• v.46 no.3
• /
• pp.31.1-31.13
• /
• 2021

Objectives: To evaluate postoperative pain after endodontic treatment of necrotic teeth using large intentional foraminal enlargement (LIFE). Materials and Methods: The sample included 60 asymptomatic necrotic teeth (with or without chronic apical periodontitis), and a periodontal probing depth of 3 mm, previously accessed and referred to perform endodontic treatment. After previous procedures, the position and approximate size of the apical foramen (AF) were determined by using an apex locator and K flexo-files, respectively. The chemomechanical preparation was performed with Profile 04 files 2 mm beyond the AF to achieve the LIFE, using 2.5 mL of 2.5% NaOCl at each file change. The filling was performed by Tagger's hybrid technique and EndoFill sealer. Phone calls were made to all the patients at 24, 48 and 72 hours after treatment, to classify postoperative pain. Statistical analysis was performed by different tests with a significance level of 5%. Results: Age, gender, periradicular status and tooth type did not influence postoperative pain (p > 0.05). Only 1 patient (1.66%) reported severe pain after 72 hours. Moderate pain was reported by 7, 4 and 3 patients after 24, 48 and 72 hours, respectively (p = 0.0001). However, paired analyses showed a statistically significant difference only between 24 and 72 hours (p = 0.04). Sealer extrusion did not influence the postoperative pain (p > 0.05). Conclusions: Acute or moderate postoperative pain was uncommon after endodontic treatment of necrotic teeth with LIFE.

• Restorative Dentistry and Endodontics
• /
• v.46 no.1
• /
• pp.5.1-5.13
• /
• 2021

Objectives: The aim of the current study was to assess whether the amount of extruded debris differs for straight and severely curved root canals during retreatment using H-files, R-Endo, Reciproc and ProTaper Universal Retreatment (PTU-R) files. Additionally, the area of residual filling material was evaluated. Materials and Methods: Severely curved (n = 104) and straight (n = 104) root canals of maxillary molar teeth were prepared with WaveOne Primary file and obturated with gutta-percha and AH Plus sealer. Root canal filling materials were removed with one of the preparation techniques: group 1: H-file; group 2: R-Endo; group 3: Reciproc; group 4: PTU-R (n = 26). The amount of extruded material and the area of the residual filling material was measured. The data were analyzed with 2-way analysis of variance (ANOVA) and 1-way ANOVA at the 0.05 significance level. Results: Except for Reciproc group (p > 0.05), PTU-R, R-Endo, and H-file systems extruded significantly more debris in severely curved canals (p < 0.05). Each file system caused more residual filling material in severely curved canals than in straight ones (p < 0.05). Conclusions: All instruments used in this study caused apical debris extrusion. Root canal curvature had an effect on extruded debris, except for Reciproc system. Clinicians should be aware that the difficult morphology of the severely curved root canals is a factor increasing the amount of extruded debris during the retreatment procedure.

• Restorative Dentistry and Endodontics
• /
• v.47 no.2
• /
• pp.18.1-18.9
• /
• 2022

Objectives: This study evaluated alterations in neuronal conductivity related to calcium silicate cements (CSCs) by investigating compound action potentials (cAPs) in rat sciatic nerves. Materials and Methods: Sciatic nerves were placed in a Tyrode bath and cAPs were recorded before, during, and after the application of test materials for 60-minute control, application, and recovery measurements, respectively. Freshly prepared ProRoot MTA, MTA Angelus, Biodentine, Endosequence RRM-Putty, BioAggregate, and RetroMTA were directly applied onto the nerves. Biopac LabPro version 3.7 was used to record and analyze cAPs. The data were statistically analyzed. Results: None of the CSCs totally blocked cAPs. RetroMTA, Biodentine, and MTA Angelus caused no significant alteration in cAPs (p > 0.05). Significantly lower cAPs were observed in recovery measurements for BioAggregate than in the control condition (p < 0.05). ProRoot MTA significantly but transiently reduced cAPs in the application period compared to the control period (p < 0.05). Endosequence RRM-Putty significantly reduced cAPs. Conclusions: Various CSCs may alter cAPs to some extent, but none of the CSCs irreversibly blocked them. The usage of fast-setting CSCs during apexification or regeneration of immature teeth seems safer than slow-setting CSCs due to their more favorable neuronal effects.

• Journal of the korean academy of Pediatric Dentistry
• /
• v.31 no.2
• /
• pp.267-272
• /
• 2004

This case report describes an uncommon treatment method for crown-root fractured incisor with immature root. A 7-year-old girl was referred for treatment of crown-root fractured maxillary central incisor. The fracture line extended to 1/2 of the total tooth length with incomplete root formation. The prognosis of crown-root fracture is usually poor and extraction is usually undertaken. But, in the mixed dentition, extraction of maxillary permanent incisor results in many complications, such as resorption of alveolar bone, poor esthetics, pronunciation and mastication. Conservative therapy in the permanent dentition comprises of few treatment modalities; supragingival restoration, gingivectomy, orthodontic extraction of apical fragment, surgical extrusion of apical fragment with or without rotational replantation. However, in this case, these indications are not applicable, so intentional replantation with adhesive resin system is the treatment of choice. The tooth was followed-up for 12 months. Currently, there are no symptoms. Since this modality adopts the respective advantages of both intentional replantation and adhesive treatment, it might be the treatment of choice in cases of vertical crown-root fracture.

• Korean Journal of Plant Tissue Culture
• /
• v.27 no.1
• /
• pp.31-37
• /
• 2000

Proton extrusion by hairy roots of Panax ginseng C.A. Meyer was enhanced by iron-deficiency or single salt solutions of nitrate or ammonium salts. The enhancement effect of iron-deficiency was confined to the apical zones, whereas that of nitrate and ammonium was confined to the basal root zones. tinder iron-deficiency medium, the proton extrusion of ginseng hairy roots was higher at two times than that grown in the medium of iron-sufficiency. According to pH in the medium, uptake of inorganic elements showed various patterns for the kind of inorganic elements. $Ca^{2＋}$, $Mg^{2＋}$ and Fe$^{2＋}$ were highest uptake at the pH 4.8 and Mn$^{2＋}$, Zn$^{2＋}$ and Cu$^{2＋}$ were highest uptake at the pH 3.8. Free sugars and ginsenosides were analyzed by HPLC. Five kinds of free sugars were indentified in ginseng hairy roots. Glucose, fructose and sucrose were a major sugar in ginseng hairy roots and contents of free sugars were highest at pH 6.8 and pH 4.8, respectively. The contents of ginsenosides and phenolic compounds were highest at pH 5.8. This physiological responses in ginseng hairy root indicated that it may well be a good model system for the study of mechanism of mobilization and uptake of inorganic elements related with the red-colored phenomenon in ginseng roots.

• The korean journal of orthodontics
• /
• v.49 no.3
• /
• pp.188-193
• /
• 2019

Objective: The aim of this finite element study was to clarify the mechanics of tooth movement in palatal en-masse retraction of segmented maxillary anterior teeth by using anchor screws and lever arms. Methods: A three-dimensional finite element method was used to simulate overall orthodontic tooth movements. The line of action of the force was varied by changing both the lever arm height and anchor screw position. Results: When the line of action of the force passed through the center of resistance (CR), the anterior teeth showed translation. However, when the line of action was not perpendicular to the long axis of the anterior teeth, the anterior teeth moved bodily with an unexpected intrusion even though the force was transmitted horizontally. To move the anterior teeth bodily without intrusion and extrusion, a downward force passing through the CR was necessary. When the line of action of the force passed apical to the CR, the anterior teeth tipped counterclockwise during retraction, and when the line of action of the force passed coronal to the CR, the anterior teeth tipped clockwise during retraction. Conclusions: The movement pattern of the anterior teeth changed depending on the combination of lever arm height and anchor screw position. However, this pattern may be unpredictable in clinical settings because the movement direction is not always equal to the force direction.

• Journal of the korean academy of Pediatric Dentistry
• /
• v.37 no.3
• /
• pp.381-386
• /
• 2010

As the vertical fracture occurs at the various locations following the long axis of a root, treatment method of crown-root fractured anterior teeth is decided according to the depth. If the fracture line is close to the crown, gingivectomy, orthodontic - forced eruption or surgical extrusion of apical fragment could be done. If the line is over 1/3 length of the root, the prognosis is poor and extraction is usually undertaken. However, extraction of maxillary incisor at growing children causes many complications such as esthetic, phonetic problem and alveolar bone resorption. Therefore, preservation of tooth is the highest priority. Recently, intentional replantation with composite resin could be considered as alternative treatment of crown-root fractured anterior tooth. This report presents a patient in mixed dentition with deep vertical crown-root fracture of the maxillary permanent central incisors by trauma. Intentional replantation of the fractured teeth was performed using composite resin. After 2 years, specific clinical symptom has not been found and the patient was satisfied of esthetic result. This method suggests the new technique to preserve a tooth as an alternative to extraction, although it is technically sensitive and the reports of long-term prognosis is insufficient.

• Journal of Dental Anesthesia and Pain Medicine
• /
• v.23 no.2
• /
• pp.91-99
• /
• 2023

Background: Extrusion of debris is a major factor that results in postoperative pain during root canal treatment with various instruments and instrumentation techniques. Therefore, instrumentation techniques that extrude minimal debris into the periapical area while reducing pain are desirable. This study aimed to compare the incidence of postoperative pain and intake of analgesic medication (frequency and quantity) after endodontic treatment of mandibular posterior teeth using two single files and full-sequence continuous rotary systems with different kinematic motions. Methods: Thirty-five of 105 patients were assigned equally to three groups according to the instrumentation system used: ProTaper Next (PN) X2, 25/06 (Dentsply, Maillefer, Ballaigues, Switzerland), One Shape (OS), #0.25/06 (Micro Mega, Besancon, France), and Wave One Gold (WG), Red - #0.25, 0.07 (Dentsply, Maillefer, Ballaigues, Switzerland). Five specialists were included in this study design; each professional prepared 21 teeth, and randomly selected 7 per instrument system. The VAS sheet ranging from 0 to 10 was used to record the initial and postoperative pains at 24, 48, and 72 h, and 7^th day after single visit endodontic treatment in mandibular premolars and molars with a diagnosis of asymptomatic irreversible pulpitis with or without apical periodontitis. Postoperatively, an analgesic, ibuprofen 400 mg was administered for intolerable pain at a dose of 1 tablet for 6 h. The patients were asked over the telephone regarding postoperative pain at intervals of 24, 48, and 72 h, and 7^th day using a visual analogue scale. Result: There were no statistically significant differences among the PN, OS, and WG systems (P > 0.05) with regard to the incidence of postoperative pain at any of the four time points assessed. Conclusion: The intensity of postoperative pain, frequency, and analgesic intake were similar across all three types of instrument systems; however, the reciprocating single file (WG) was associated with less postoperative pain than the full sequence continuous rotary file.

• The korean journal of orthodontics
• /
• v.25 no.4
• /
• pp.403-414
• /
• 1995

The purpose of this study was to investigate the histologic changes in mandibular periodontium during overbite closure for openbite treatment by continuous arch wires and anterior vertical elastics. Two female monkey(Macaca nemestrina) with permanent dentition were used. Posterior bite block was fixed to each of their maxillae, which made the animal temporary anterior openbite as well as stabilized the whole maxillary anchorage. In each mandible, all the teeth except the second molars which had been extracted, were prepared for cast crowns. 018 inch Standard brackets were welded on these crowns. After cementation, two types of the $016{\times}022$ inch continuous arch wires, the plain ideal arch to the control animal and the MEAW(multiloop edgewise archwire) to the other experimental one were inserted. Then anterior vertical elastics were applied for two weeks. The overbite depth changes in the monkeys and histologic examinations of the mandibular periodontiums suggested the following conclusions. 1. During two weeks of the experimental period, the overbite increased + 0.3 mm in the control and + 1.3 mm in the experimental one. 2. In both the control and the experimental animal, histologic examinations showed that incisors, canines and first premolars were subject to extrusive force and the rest of posteriors were subject to intrusive one. 3. In periodontiums of the extruded incisors of the experimental one, reorientation of the periodontal fiber structures reflected the direction of force and the alveolar bone surfaces including apical and crestal areas which had been subject to tension, were the front of new bone formation. 4. In periodontiums of the extruded incisors of the experimental one, neither excessive hyalinization nor gross root resorption was observed. 5. Alveolar bone remodeling of anteriors and posteriors was more remarkable in the experimental one than the control.