OBJECTIVETo investigate the effects of post space preparation and post restoration on apical sealing ability.

METHODS60 extracted mandibular premolars each with single canal were selected. All canals were prepared by manual ProTaper instrument using crown-down technique. The samples were the divided into 5 groups randomly. Group A: 20 samples, the immediate post space preparation group; group B: 20 samples, the delayed post space preparation group; group C: 10 samples, the intact group; group D: 5 samples, a positive control; group E: 5 samples, a negative control. There were two subsets in groups A and B which were restored by temporary materials (A1 and B1) or fiber post and cores (A2 and B2). Indian ink dye method was used to measure the apical leakage in stereomicoscope.

RESULTSThe mean length of dye penetration for group A1, A2, B1, B2 and C were (0.52 +/- 0.47), (0.49 +/- 0.44), (1.17 +/- 0.77), (1.12 +/- 0.54), and (0.23 +/- 0.40) mm, respectively. Positive group demonstrated maximum dye penetration, and negative group showed no dye penetration. There was no statistically significant difference between group A1, A2 and group C (P>0.05). However, there were statistically significant differences between group B and group A, C (P<0.05). The length of dye penetration for group B was longer than that for group A and C.

CONCLUSIONThe sealing ability was decreased after delayed post space preparation when using the AH-Plus sealer.

OBJECTIVETo compare the sealing ability and fracture resistance of roots endodontically treated with bonded and unbonded filling materials.

METHODSOne hundred and fifteen straight mandibular premolar teeth with single canal were divided randomly into 6 experimental groups, with 15 samples each, and 3 control groups. The sealing ability was evaluated using a glucose quantitative microleakage mode and fracture resistance was tested by universal testing machine.

RESULTSThe microleakage results showed that the bonded filling material had the lowest value while the unbonded filling material had the highest value in all groups. There were significant differences in microleakage value among the groups (P < 0.01), but no significant difference was noted in the fracture resistance among the testing groups (P = 0.7016).

CONCLUSIONSBonded filling material enhanced the sealing ability but could not reinforce the fracture resistance of endodontically treated teeth.

The flowability of a root canal sealer is clinically important because it improves the penetration of the sealer into the complex root canal system. The purpose of this study was to compare the flowabilities of four root canal sealers, measured using the simple press method (ISO 6876), and their viscosities, measured using a strain-controlled rheometer. A newly developed, calcium phosphate-based root canal sealer (Capseal) and three commercial root canal sealers (AH Plus, Sealapex and Pulp Canal Sealer EWT) were used in this study. The flowabilities of the four root canal sealers were measured using the simple press method (n=5) and their viscosities were measured using a strain-controlled rheometer (n=5). The correlation between these two values was statistically analysed using Spearman's correlation test. The flow diameters and the viscosities of the root canal sealers were strongly negatively correlated (ρ=-0.8618). The viscosity of Pulp Canal Sealer EWT was the lowest and increased in the following order: AH Plusroot canal sealers showed characteristic time- and temperature-dependent changes in their rheological properties. The viscosities measured using the strain-controlled rheometer were more precise than the flowabilities measured using the simple press method, suggesting that the rheometer can accurately measure the rheological properties of root canal sealers.
Materials Testing ; Rheology ; Root Canal Filling Materials ; Temperature ; Viscosity

Root canal filling is performed as the final and most important procedure of root canal treatment. The superior 3D filling is the key determinant of endodontic success. However, such procedure remains a challenge because of the complexity of the root canal system and the limitation of root canal filling materials and methods. This paper provides an overview of current principles and practices in root canal filling, focusing on advantages, disadvantages and indications. The process errors and countermeasures in various root canal filling methods are also discussed. This review provides guidance and help for clinical and practice to achieve a satisfactory root canal filling and improve root canal treatment outcome.
Dental Pulp Cavity ; Humans ; Root Canal Filling Materials ; Root Canal Obturation ; Root Canal Therapy

Humans ; Root Canal Filling Materials ; Root Canal Therapy ; methods ; Tooth Root ; physiopathology

Perforations are common complications of root canal therapy. In clinic, perforations that were improperly and untimely repaired can seriously affect the prognosis of teeth after root canal treatment. At present, the status of perforation repair in our country is worrisome. This paper focused on the progress of perforation repair in the country by discussing the current situation of repair methods and materials. This review aims to improve knowledge and aid clinical doctors in the sophistication of perforation repair in order to improve the retention rate of root-canal-treated teeth.
Drug Combinations ; Root Canal Filling Materials ; Root Canal Therapy ; adverse effects ; Tooth Root

Humans ; Root Canal Filling Materials ; Root Canal Obturation ; methods ; Tooth Root ; physiopathology

OBJECTIVETo evaluate the therapeutic effect of teeth with large periapical lesions followed apical surgery.

METHODS59 patients (59 periapical lesions, 91 teeth) with large periapical lesions ranging in size from 6 mm to 21 mm in diameter were included in this study. All teeth were treated by root canal therapy and apical surgery, and the surgical procedure was completed with microsurgical technology and ultrasonic root-end preparation. The outcomes were evaluated clinically and radiographically at 1, 3, 6, 9, 12 and 24-month intervals, and the various factors which may affect the success rate were analyzed statistically.

RESULTS52 cases (88.1%) of 59 patients were considered success, 6 cases (10.2%) were considered failure, and 1 case (1.7%) was considered in progress. The success rate of elderly patients group (63.6%) was significantly lower than that of the youth group (87.5%) and middle-aged group (95.0%) (P = 0.037; P = 0.017). The success rate of molar group (75.0%) was significantly lower than that of the anterior group (92.6%) and the premolar group (90.0%) (P = 0.041, P = 0.047); however, there was no significant difference in the gender, the number of teeth invaded in lesions, the size of periapical lesion (P > 0.05).

CONCLUSIONIt is an effective therapy for the teeth with large periapical lesions by apical surgery after root canal treatment.

OBJECTIVETo compare the clinical effect of different tapered gutta-percha root filling by warm vertical condensation with immediate postoperative radiographs and one year follow-up.

METHODS40 maxillary anterior teeth with single, straight canals were divided into two equal groups. The teeth were instrumented with Hero 642 rotary nickel-titanium files to a master file 0.06 taper No. 30. Group 1 was obturated with 0.02 tapered gutta-percha using System B for downpack and Obtura II for backfilling. Group 2 was the same but 0.06 tapered gutta-percha. Every tooth's X-ray radiographs of immediate postoperative and one year follow-up were taken. In order to compare the quality of root canal filling, the rate of filling material extrusion, and the rate of obturation of lateral canals in each group were evaluated by X-ray radiographs. The clinical effect of one year follow-up's radiographs of the two groups was compared too.

RESULTSThere was no significant difference in two groups on the quality of the root canal filling, obturation of lateral canals, and filling material extrusion. The success of the therapy was similar. But the 0.06 tapered gutta-percha group showed more quickly healing trend on apical periodontitis.

CONCLUSIONWhen single, straight root canals were obturated using warm vertical condensation, adaptively tapered gutta-percha showed better clinical effect.

OBJECTIVETo study the relation on overfilling with gutta-percha point or paste and acute periapical periodontitis.

METHODSCollected sixty cases of acute periapical periodontitis which had been filled with gutta-percha point and paste within 1 week, and took dental radiographs. The cases that dental radiographs showed only guttapercha point was overfilling were assigned to group A (34 cases), and the cases that dental radiographs showed only paste was overfilling were assigned to group B (26 cases). The cases that dental radiographs showed both gutta-percha point and paste were overfilling were excluded. Sixty cases were divided into light group and severe group according to clinical sign. Measured gutta-percha point length or paste areas over apex. Took out the ohturation material cornpletely, adjusted occlusion when necessary and changed root canal medicament every day until clinical sign disappeared completely. Recorded the time of clinical sign disappeared completely.

RESULTSIn group A, gutta-percha point length over apex averaged 1.01 mm on light cases, and 1.79 mm on severe cases. In group B, the paste areas over apex averaged 2.45 mm2 on light cases, and 8.26 mm2 on severe cases. Group A had 13 light cases and 21 severe cases, and group B had 18 light cases and 8 severe cases. In group A, the average time of clinical sign disappeared completely was 3.56 days, and in group B the average time was 6.19 days. The statistical test showed there were significant differences among these four couples.

CONCLUSIONThe more overfilling, the more severe clinical sign was. Clinical sign caused by gutta-percha point overfilling was more severe. The time of clinical sign which caused by gutta-percha point overfilling disappeared completely was shorter.