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.

Gutta-Percha ; Humans ; Periapical Periodontitis ; Root Canal Filling Materials ; Root Canal Preparation

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.

Dental Pulp Cavity ; Gutta-Percha ; Humans ; Nickel ; Root Canal Filling Materials ; Root Canal Obturation ; Titanium

OBJECTIVES: This study aimed to evaluate the efficacy of three methods in root canal retreatment to remove the filling material in the root canals. METHODS: Ninety tooth roots filled by gutta percha or plasticized material (n=45, each) were randomly divided into three groups (n=15). WaveOne (WaveOne group), 1^#P drill+WaveOne (1^#P+WaveOne group), and ultrasound P5 working end ET25+ProTaper Universal (P5+ProTaper Universal group) were used to remove the root canal filling material and prepare for root canal. The operating time of each canal was recorded and the percentage of residual filling material area was measured on the root canal wall of the mesial and distal dissected root section. The degree of deviation of the root canal after operation was measured for the root samples filled by gutta percha. RESULTS: The type of root filling material and the method of root canal retreatment had no significant effect on the percentage of residual area of the filling material (P>0.05). However, the remaining filling material area of apical 1/3 of the root canal was significantly higher than that of cervical 1/3 of the root canal (P<0.05). The average operating times for removing gutta-percha or plasticized material in the W and 1^#P+WaveOne groups were significantly less than that in the P5+ProTaper Universal group (P=0.000). The root canal retreatment methods had no significant effect on the curvature of the root canal (P=0.650). CONCLUSIONS WaveOne single file's cleaning ability and center positioning ability were similar to those of ProTaper Universal. Moreover, WaveOne can be independently used for most root canals without a pathway when removing the root canal fillings, thereby simplifying the process of root canal retreatment.
Equipment Design ; Gutta-Percha ; Nickel ; Root Canal Filling Materials ; Root Canal Preparation/methods* ; Titanium

OBJECTIVE: To evaluate the clinical effect of root canal obturation therapy using cold flowable gutta-percha on young permanent teeth after apexification. METHODS: Ninety cases of young permanent teeth with pulp necrosis or periapical periodontitis treated by apexification were randomly divided into two groups. The cases in each group were divided into single root canal and multiple root canal according to the number of the root canal, and divided into classifications Ⅰ, and Ⅱ/Ⅲ/Ⅳ according to Frank's classification of root development after apexification. Cold flowable gutta-percha and warm gutta-percha obturation techniques were used for root canal obturation of the two groups. The operation time was recorded, and the patients' therapy pain degree was evaluated by visual analog scale (VAS) immediately after operation. Periapical X-ray was performed after operation to evaluate the effect of the root canal filling. The total length of the root was divided into equal three parts on the X-ray film, and three-dimensional tightness of the apical, middle, and coronal region of the root canals were statistically analyzed respectively. Clinical examinations and X-ray examination were performed 6 and 12 months after the operation to evaluate the treatment success rate. RESULTS: The operation time of cold flowable gutta-percha group was significantly lower than that of the control group, which were 51 s and 74 s (P < 0.05); The percentages of pain and discomfort in the two groups were 26.67% and 40.00%, respectively. There were two cases of underfilling and no overfilling in both groups. The percentages of proper filling and tight three-dimensional obturation in the experimental and control groups were 71.11% and 60.00% respectively; and the percentages of tight three-dimensional obturation in the apical third areas were 86.67% and 66.67%, the difference was significant (P < 0.05). There was no significant difference in the three-dimensional tightness between the two groups in the middle and coronal third areas. The percentages of tight three-dimensional obturation in classification Ⅰ groups were 86.67%, 83.33%, 93.33% and 76.67%, 90.00%, 96.67% in experimental and control group, respectively; The percentages of classification Ⅱ/Ⅲ/Ⅳ groups were 86.67%, 86.67%, 100.00% and 46.67%, 86.67%, 100.00%, respectively, and the difference was significant (P < 0.05). There were no apical lesions that occurred in either group during the one-year review period. CONCLUSION The application of cold flowable gutta-percha on young permanent teeth root canal obturation after apexification can achieve good obturation effect. The root obturation effect in the apical third area is significantly better than that of warm gutta-percha obturation techniques. Cold flowable gutta-percha can shorten the clinical treatment time and ameliorate the patients' therapy comfort.
Apexification ; Dental Pulp Cavity ; Gutta-Percha ; Humans ; Radiography ; Root Canal Filling Materials ; Root Canal Obturation ; Root Canal Preparation

Compared with cold lateral condensation and continuous wave of condensation which are classically used in clinical, newly emerging single-cone obturation technique is easy-to-operate as well as time-saving. Especially when combined with bioceramic root canal sealers of improved physicochemical and biological properties, single-cone obturation technique showed satisfactory short-term outcomes in clinical observations. However, difficulties still exist in avoiding the root canal overfilling and in operating the retreatment. Besides, the long-term effects of single-cone obturation with bioceramic sealers still remain unclear. This article makes an overview on the history and development of single-cone obturation ,and provides analysis of its pros and corns. Furthermore, we would also like to summarize its clinical application and look into its future improvements.
Epoxy Resins/chemistry* ; Gutta-Percha/chemistry* ; Retreatment ; Root Canal Filling Materials/therapeutic use* ; Root Canal Obturation/methods* ; Root Canal Therapy

OBJECTIVETo compare the fracture resistance of roots filled with three different root canal filling techniques.

METHODSForty extracted single-rooted permanent teeth were instrumented and randomly divided into four groups. Three experimental groups were filled with lateral compaction technique, vertical compaction technique and single-cone technique, respectively. No filling was performed in control group. All specimens were subjected to a vertical load to cause vertical root fracture. The force required to fracture was measured and the fracture lines was classified.

RESULTSThree experimental groups exhibited higher mean fracture load values than that of control group (179.93 N+/-34.03 N). There was no significant difference among the three experimental groups, and the mean fracture load values were (210.041+/-64.57), (232.55+/-50.74), (216.80+/-78.03) N, respectively. Eighty-five percent of root fracture lines were found in the bucco-lingual direction.

CONCLUSIONRoot canal filling alone can't influence the root strength significantly. There is no difference in root strength after three canal filling techniques.

Dental Pulp Cavity ; Dental Stress Analysis ; Gutta-Percha ; Humans ; Root Canal Filling Materials ; Root Canal Obturation ; Tooth Fractures ; Tooth Root

OBJECTIVES: The purpose of this study was to observe the change in the viscoelastic properties of thermoplasticized injectable root canal filling materials as a function of temperature and to compare the handling characteristics of these materials. MATERIALS AND METHODS: Three commercial gutta perchas and Resilon (Pentron Clinical Technologies) in a pellet form were heated in the Obtura-II system (Obtura Spartan) at 140degrees C and 200degrees C, and the extrusion temperature of the thermoplasticized materials was measured. The viscoelastic properties of the materials as a function of temperature were evaluated using a rheometer. The elastic modulus G', viscous modulus G", loss tangent tandelta, and complex viscosity eta* were determined. The phase transition temperature was determined by both the rheometer and a differential scanning calorimeter (DSC). The consistency of the materials was compared under compacting pressure at 60degrees C and 40degrees C by a squeeze test. RESULTS: The three gutta perchas had dissimilar profiles in viscoelastic properties with varying temperature. The phase transition of softened materials into solidification occurred at 40degrees C to 50degrees C, and the onset temperatures obtained by a rheometer and a DSC were similar to each other. The onset temperature of phase transition and the consistency upon compaction pressure were different among the materials (p < 0.05). Resilon had a rheologically similar pattern to the gutta perchas, and was featured between high and low-flow gutta perchas. CONCLUSIONS: The rheological characteristics of the thermoplasticized root canal filling materials changed under a cooling process. The dissimilar viscoelastic properties among the materials require different handling characteristics during an injecting and compacting procedure.
Elastic Modulus ; Gutta-Percha ; Handling (Psychology) ; Hot Temperature ; Phase Transition ; Root Canal Filling Materials ; Viscosity

OBJECTIVES: The safety of root canal filling with 200 °C hot gutta-percha was investigated to study the effect of continuous wave technique combined with high-temperature injectable gutta-percha condensation technique on the surface temperature of periodontal tissue. METHODS: CT technique and Mimics, Geomagic, and Solidworks software were utilized to build the entity models of alveolar bone, dentin and root canal, periodontal ligament, and blood flow, respectively, which were then assembled in Solidworks into a finite element model of tooth with blood flow. By utilizing ABAQUS collaborative simulation platform, fluid-structure coupling was analyzed on the whole process of root canal filling. Consequently, the surface temperature of the periodontal tissue was obtained. RESULTS: In the absence of blood flow, the temperature of the periodontal ligament surface reached 50.048 ℃ during root canal filling with 200 ℃ gutta-percha. Considering blood flow, the temperature of periodontal ligament surface was 39.570 ℃. CONCLUSIONS The temperature of the periodontal ligament surface increased when the continuous wave root canal was filled with 200 ℃ gutta-percha, and the periodontal tissue was not damaged.
Dental Pulp Cavity ; Finite Element Analysis ; Gutta-Percha ; Hot Temperature ; Humans ; Periodontium ; Root Canal Filling Materials ; Root Canal Obturation ; Temperature

OBJECTIVETo establish the three-dimensional model of human permanent premolars based on Micro-computed tomography (Micro-CT) data, and evaluate the efficiency quantitatively of two different instrumentations for root canal retreatment.

METHODSForty extracted permanent premolars for the reason of orthodontic treatment were collected, prepared by using ProTaper Ni-Ti files and filled by cold gutta pertscha lateral condensation technique. The subjects were scanned by Micro-CT. Forty teeth were randomly divided into two groups and retreated by K-Flexo files and ProTaper Universal retreatment system respectively. Then all subjects were scanned again, and the mean percentage of remaining filling materials and the scores of remaining filling materials presented in upper, middle and apical 1/3 of the canal were calculated.

RESULTSMean percentage of the remaining filling materials by K-Flexo files was lower than that by ProTaper Universal retreatment system (P=0.005). The scores demonstrated that K-Flexo files had greater efficiency than ProTaper Universal retreatment system when retreating the apical 1/3 of canal (P<0.05).

CONCLUSIONThis study shows that both techniques could not remove filling materials completely.

Dental Alloys ; Dental Pulp Cavity ; Gutta-Percha ; Humans ; Nickel ; Retreatment ; Root Canal Filling Materials ; Root Canal Preparation ; Root Canal Therapy ; Titanium ; X-Ray Microtomography

The purpose of this study was to evaluate the thermal expansion characteristics of injectable thermoplasticized gutta-perchas and a Resilon. The materials investigated are Obtura gutta-percha, Diadent gutta-percha, E&Q Gutta-percha Bar and Epiphany (Resilon). The temperature at the heating chamber orifice of an Obtura II syringe and the extruded gutta-percha from the tip of both 23- and 20-gauge needle was determined using a Digital thermometer. A cylindrical ceramic mold was fabricated for thermal expansion test, which was 27 mm long, with an internal bore diameter of 3 mm and an outer diameter of 10 mm. The mold was filled with each experimental material and barrel ends were closed with two ceramic plunger. The samples in ceramic molds were heated in a dilatometer over the temperature range from 25degrees C to 75degrees C. From the change of specimen length as a function of temperature, the coefficients of thermal expansion were determined. There was no statistical difference between four materials in the thermal expansion in the range from 35degrees C to 55degrees C (p > 0.05). However, Obtura Gutta-percha showed smaller thermal expansion than Diadent and Metadent ones from 35degrees C to 75degrees C (p < 0.05). The thermal expansion of Epiphany was similar to those of the other gutta-percha groups.
Ceramics ; Dental Pulp Cavity* ; Fungi ; Gutta-Percha ; Heating ; Hot Temperature ; Needles ; Root Canal Filling Materials* ; Syringes ; Thermometers