• Restorative Dentistry and Endodontics
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• v.22 no.1
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• pp.244-253
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• 1997

During preparation of narrow curved canals, procedural accidents such as, ledge, zipping, and transportation are frequently encountered and may lead to failure of endodontic therapy. To reduce these procedural errors and efficiently manage curved canals, various modifications in instrumentation technique and the design and flexibility of instruments have been advocated. This study compared the maintenance of the original canal curvature, cross sectional canal shape, and preparation time during instrumentation with stainless steel hand (K-Flexo) file, and nickel-titanium rotary files (Profile and Lightspeed). Thirty resin blocks with simulated curved canals of 20~25 degrees were used and divided into three groups of 10 each. In group 1, canals were instrumented using a quarter turn/pull technique with K-Flexofiles. Group 2 canals were prepared with rotary NiTi Profiles. Group 3 was prepared with rotary NiTi Lightspeed instrument. Before and after instrumentation, all canals were scanned using stereo microcope, FlexCam camera, and Photoshop 3.0 computer program. The results were as follows : 1. All groups showed some loss of canal curvature after instrumentation. Average loss of canal curvature was 8.6 degrees for K-Flexofile, 7.7 degrees for Profile, and 5.8 degrees for Lightspeed. Lightspeed exhibited significantly less curvature loss than K-Flexofile (p<0.05). 2. At the apical 1-mm level, Profile produced significantly rounder canals than Lightspeed (p<0.05). At the 3-mm level, Profile and Lightspeed exhibited significantly rounder canals than K-Flexofile (p<0.05). 3. Preparation with Lightspeed was significantly faster than Profile and K-Flexofile, and Profile was faster than K-Flexofile (p<0.05). 4. There was no significant difference in incidence of zipping between the hand K-Flexofile and rotary NiTi (Profile and Lightspeed) instruments. Most of apical canals were slightly widened near the apical foramen. As a results of this study, rotary NiTi instruments are superior to the K-Flexofile in regard to the maintenance of original canal curvature, cross-sectional shape and preparation time. But more investigations and studies should be needed to evaluate the ideal canal instrumentation.

• Journal of Veterinary Clinics
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• v.30 no.5
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• pp.380-383
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• 2013

This clinical report describes the dental treatment of canine teeth fractures in three cats. These animals were diagnosed by oral examination and dental radiography as having fractured teeth with pulpal exposure. After endodontic treatment was completed, root canal filling material was removed from the coronal access and a trial post placement was performed. The post was permanently cemented after shortening. Teeth were etched and a bonded composite resin core formed and then shaped using rotary instruments. Fractured canine teeth were treated without any complications observed during a six-month follow-up period, proving that fractured cat canine teeth can be treated successfully with root canal therapy followed by restorative treatment with posts and composite resin.

• Journal of the korean academy of Pediatric Dentistry
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• v.28 no.4
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• pp.575-582
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• 2001

There have been many treatment methods for traumatic subgingival crown fracture and intrusion without spontaneous eruption. The orthodontic forced eruption generally results in favorable clinical findings than crown lengthening with osteotomy and intentional replantation. In first two cases with subgingival crown fracture due to trauma, authors applied orthodontic forced eruption with axed appliance after root canal therapy and then restored them with composite resin. In another case with traumatic intrusive luxation, we observed spontaneous eruption of the corresponding tooth for about 6 months and then returning it to normal position by forced eruption with removable appliance, but root canal filling was conducted after apexification due to devitalization during forced eruption, and so clinically favorable results were obtained.

• Journal of Dental Anesthesia and Pain Medicine
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• v.22 no.5
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• pp.377-385
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• 2022

Background: Postoperative endodontic pain is an enigma for the dentist. This study aimed to evaluate the analgesic effect of 300 mg gabapentin or 75 mg pregabalin in reducing postoperative endodontic pain compared with a placebo. Methods: Ninety patients who needed root canal treatment with an initial numerical rating scale (NRS) pain score of > 4 (T0) were randomly divided into three groups (n=30). Patients were then administered either 300 mg gabapentin (group A), 75 mg pregabalin (group B), or a placebo (group C) 30 min prior to the start of endodontic treatment. A single operator performed single-visit endodontics, and pain was evaluated immediately after endodontic treatment (T1) and at 4 h (T2), 8 h (T3), 12 h (T4), 24 h (T5), 48 h (T6), and 72 h (T7) using the NRS. Ibuprofen/paracetamol (400 mg/325 mg) was administered as a rescue dose if needed. Results: Pregabalin performed significantly better when compared with gabapentin at all time points except at 72 h after treatment (P=0.170). The placebo group showed significantly higher pain scores than the other two groups. The percentage of pain relief was maximum for pregabalin (92.1%), followed by gabapentin (87.6%) and placebo (69.1%) at 72 h after treatment completion. Conclusion: This study showed that pretreatment with a single dose of pregabalin and gabapentin both had greater analgesic effects than a placebo. They can be effectively used to reduce postoperative endodontic pain.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.50 no.3
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• pp.140-145
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• 2024

Objectives: The necessity of retrograde filling after apicoectomy is controversial in cases of non-inflammatory cysts as opposed to bacteria-related periapical abscesses. This study aims to investigate whether the presence or absence of retrograde filling during apicoectomy has differential long-term prognostic implications between inflammatory and non-inflammatory cysts. Materials and Methods: This retrospective study included patients who underwent tooth apicoectomy during jaw cyst enucleation between 2013 and 2022, and who underwent follow-up cone-beam computed tomography for at least 6 months. The prognosis of the tooth was evaluated during the follow-up period according to the cyst type, the presence or absence of retrograde filling, mandible or maxilla, and location. Results: A total of 147 teeth was included in this study. All the operated teeth underwent preoperative root canal treatment by an endodontic specialist. Apicoectomy was performed for 119 inflammatory cysts and 28 non-inflammatory cysts. Retrograde filling was performed on 22 teeth with inflammatory cysts and 3 teeth with non-inflammatory cysts. All teeth survived the 3.5-year follow-up (range, 1.0-9.1 years). However, 1 tooth with an inflammatory cyst developed complications 1 year after surgery that required re-endodontic treatment. Conclusion: The prognosis of a tooth treated by apicoectomy without retrograde filling during cyst enucleation is favorable, regardless of the cyst type.

• Restorative Dentistry and Endodontics
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• v.46 no.4
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• pp.56.1-56.11
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• 2021

Objectives: This study evaluated 2 nickel-titanium rotary systems and a complementary protocol with an ultrasonic tip and a small-diameter instrument in flattened root canals. Materials and Methods: Thirty-two human maxillary second premolars with flattened canals (buccolingual diameter ≥4 times larger than the mesiodistal diameter) at 9 mm from the radiographic apex were selected. The root canals were prepared by ProDesign Logic (PDL) 30/0.01 and 30/0.05 or Hyflex EDM (HEDM) 10/0.05 and 25/0.08 (n = 16), followed by application of the Flatsonic ultrasonic tip in the cervical and middle thirds and a PDL 25/0.03 file in the apical third (FPDL). The teeth were scanned using micro-computed tomography before and after the procedures. The percentage of volume increase, debris, and uninstrumented surface area were analyzed using the Kruskal-Wallis, Dunn, Wilcoxon, analysis of variance/Tukey, and paired and unpaired t-tests (α = 0.05). Results: No significant difference was found in the volume increase and uninstrumented surface area between PDL and HEDM (p > 0.05). PDL had a higher percentage of debris than HEDM in the middle and apical thirds (p < 0.05). The FPDL protocol resulted in less debris and uninstrumented surface area for PDL and HEDM (p < 0.05). This protocol, with HEDM, reduced debris in the middle and apical thirds and uninstrumented surface area in the apical third (p < 0.05). Conclusions: High percentages of debris and uninstrumented surface area were observed after preparation of flattened root canals. The HEDM, Flatsonic tip, and 25/0.03 instrument protocol enhanced cleaning in flattened root canals.

• Restorative Dentistry and Endodontics
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• v.23 no.1
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• pp.257-268
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• 1998

During cleaning and shaping of narrow and curved canals, it is very difficult or nearly impossible to maintain the original canal shape. Procedural accidents such as, ledge, zipping, perforation, and instrument breakage are frequently occurred and even may lead to failure of endodontic therapy. To prevent these kinds of accidents, various instrumentation techniques and materials have been introduced. Recently some nickel titanium (NiTi) files are introduced and it is reported that These NiTi files created rounder preparations with less transportation than conventional instruments in curved canals. This study compared the change of the canal curvature and procedural accidents after instrumentation produced by stainless steel K-flexo file, and NiTi rotary files (Profile 29 and Quantec 2000). Thirty narrow and curved canals (25-45 degree) of extracted human molars were randomly divided into three groups. In group 1, canals were instrumented using a step-back and watch-winding/pull motion with K-flexo files. In group 2, canals were prepared with Profile 29. Group 3, canals were prepared with Quantec 2000 files. Before and after preparation of canals, periapical radiographs were taken and scanned. The change of canal curvature were measured using Photoshop 4.0 program and the incidence of procedural accidents were also evaluated. The results were as follows: 1. All group showed some loss of canal curvature after instrumentation. 2. Average loss of canal curvature was $6.70{\pm}5.31$ degree for group 1, $3.80{\pm}2.57$ degree for group 2, and $5.40{\pm}4.83$ degree for group 3. All group There was significant change in curvature between before and after instrumentation (p<0.05). But there was no statistical difference amoung 3 groups. 3. In group I, there were no procedural accidents, such as ledging, perforation, or instrument fracture. In group 2, two cases of ledge and one case of instrument fracture were produced Goup 3, each one case of ledge, perforation and instrument fracture were occurred. Whthin the limits of above results, It seems that NiTi rotary instrumentation is not All Mighty and if we use uncarefully, it is more dangerous to produce some procedural accidents than conventional hand files. But more studies should be taken to evaluate the exact effects of NiTi rotary instrumentations.

• The Journal of Korean Academy of Prosthodontics
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• v.34 no.4
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• pp.780-790
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• 1996

The endodontically treated tooth is generally restored with post and core, owing to the brittleness and the loss of large amount of tooth structure. Although there have been lots of studies about the endodontically treated teeth, the three-dimensional quantitative studies about the stress distribution of them are in rare cases. In this study, it was assumed that the coronal portion of the upper incisor had extensively damaged. After the root canal therapy it was post cored, and restored with PFG crown. The three-dimensional model, in which the root was supported with a normal alveolar bone, was constructed. Force was applied to the centric stop point with the angle of 135 degrees to the long axis of the tooth. Force was assumed to be 250N as functional maximum bite force of upper central incisors. The results analyzed with three-dimensional finite element method were as follows : 1. Stress was concentrated on the middle portion of the labial side dentin and the apical portion of the dentin. 2. Stress in the post was more concentrated on the post apex. 3. The displacement of the post at the post-cement interface was almost symmetrical la-bio-lingually. 4. It assumed that restoring extensively damaged tooth with a post-core and PFG crown is an adequate method of restoration.

• The Journal of the Korean dental association
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• v.38 no.6 s.373
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• pp.567-569
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• 2000

Many teeth have been mistakenly extracted or endodontically treated because of an incorrect diagnosis of orofacial pain including toothache, A case report of persistent toothache originating from a malignant lymphoma of left maxilary sinus is presented. Root canal therapy and extraction of left upper quadrant teeth from canine to second molar did not resolve the chief complaint. The patient was referred to a neurologist and was diagnosed with a malignant lymphoma, a rare lesion of the maxillary sinus. The case stresses the importance of malignant neoplasms of maxillary sinus as a potential etiologic factor in the differential diagnosis of orofacial pain.

• Proceedings of the KACD Conference
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• 2001.11a
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• pp.583.1-583
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• 2001

One fifth dilution of formocresol is usually used for pulpotomy of primary teeth and emergency pulpotomy of permanent teeth. Recently Depulpin (VoCo., Germany) gains popularity as devitalizing agent during root canal therapy in spite of high concentration of 49% paraformaldehyde. But there are not enough publications about the reaction of dental pulp and periapical tissue caused by Depulpin. Therefore, This study was performed to evaluate the histological changes in pulp and periapical tissue of rat after pulpotomy using formocresol and Depulpin.(omitted)