The aim of this study was to evaluate the factors affecting the healing of root fracture in immature permanent teeth and the prognosis of root fracture by statistically analyzing the relationship with the pulp and root healing.The radiographs of 51 root-fractured maxillary anterior permanent teeth were collected. In radiograph, locations of root fracture, apical foramen width and width of diastasis between the fragments were measured. The value of the studied parameters were compared by independent t-test and rogistic regression test.In conclusion, there was no difference in the prognosis of pulp healing according to the location of root fracture. However, root healing occurs well as the root fracture is located at the root apex (p < 0.05). Lastly, the smaller the width of diastasis between the fragments after reduction, the better the pulp healing was (p < 0.05).
Prognosis ; Tooth Apex ; Tooth

The purpose of this study was to investigate the quantity of debris which was extruded apically after canal instrumentation using different types of enlarging instrument in endodontic resin models. Five groups of 9 endodontic resin models were instrumented using each different technique : hand instrumentation without early coronal flaring, hand instrumentation after early coronal flaring, and three nickel-titanium engine-driven instrumentations (Hero 642, Protaper, K3). Debris extruded from apical foramen during instrumentation was collected on preweighed CBC bottle, desiccated and weighted using electronic balance. The results were analyzed using Kruskal-wallis test and Mann-Whitney U rank sum test at a significance level of 0.05. The results were as follows: 1. All of instrumentation techniques produced apically extruded debris. 2. Group without early coronal flaring extruded significant more debris than groups with early coronal flaring. 3. There was no significant difference among early coronal flaring groups. The early coronal flaring is very important to reduce the amount of debris extruded apically.
Dental Instruments ; Tooth Apex

OBJECTIVES: The purpose of this study was to evaluate the buccolingual curvature at the apical one third in type II mesial canals of mandibular molars using the radius and angle of curvature. MATERIALS AND METHODS: Total 100 mandibular molars were selected. Following an endodontic access in the teeth, their distal roots were removed. #15 H- or K-files (Dentsply Maillefer) were inserted into the mesiobuccal and mesiolingual canals of the teeth. Radiographs of the teeth were taken for the proximal view. Among them, type II canals were selected and divided into two subgroups, IIa and IIb. In type IIa, two separate canals merged into one canal before reaching the apex and in type IIb, two separate canals merged into one canal within the apical foramen. The radius and angle of curvature of specimens were examined. RESULTS: In type II, mean radius of curvature in mesiolingual and mesiobuccal canals were 2.82 mm and 3.58 mm, respectively. The radius of the curvature of mesiolingual canals were significantly smaller than that of mesiobuccal canals in type II, and especially in type IIa. However, there were no statistically significant differences in radius of curvature between mesiobuccal and mesiolingual canals in type IIb and there were no significant differences in angle of curvature between type IIa and IIb. CONCLUSION: In this study, type II mesial canals of mandibular molars showed severe curvature in the proximal view. Especially, mesiolingual canals of type IIa had more abrupt curvature than mesiobuccal canals at the apical one third.
Molar ; Radius ; Tooth ; Tooth Apex

Humans ; Incisor ; Tooth Apex ; abnormalities

The aim of this study was to evaluate the microleakage of teeth according to root canal preparation with & without apical enlargement in various size of apical foramen. 60 extracted one canal roots were cross-cutted at 5 mm from root apex and divided into two groups according to their apical foramen size of large (L) and small (S). Each group was subdivided into two groups accordance with their cross-sectional configuration at 5 mm from apex, round (R) and ovoid (O); SR Group, SO Group, LR Group, LO Group. Each group was shaped in .02 taper by Quantec series Nickel-Titanium (NiTi) rotary file, obturated by lateral condensation method. Leakage was measured using a fluid transport model under 40 cmH2O pressure. After the leakage test, blocks which had showed the leakage retreated with .04 taper and .06 taper and evaluated the degree of fluid filtration in each group. The data was analysed statistically using chi-square test and fisher's exact test. The results obtained were as follows: 1. Significant difference in leakage was found in groups which had different apical foramen size in .02 taper instrumentation (p < 0.05), but not in .04 taper instrumentation (p > 0.05). 2. The difference in microleakage according to the shape of canal was not evident at 5 mm from apex (p > 0.05). 3. There was correlation between .02 taper instrumentation and .04 taper instrumentation in LR group , LO group (p < 0.05).
Filtration ; Root Canal Preparation ; Tooth Apex ; Tooth*

This study was done to evaluate transportation of the apical foramen after 0.5 mm overinstrumentation by ProFile, ProTaper and K3 in simulated resin root canal. Sixty simulated resin root canal with a curvature of J and S-shape were divided into two groups. Each group consisted of three subgroups with 10 blocks according to the instruments used: ProFile(R), ProTaper(TM), and K3TM. Simulated resin root canal was prepared by ProFile, ProTaper and K3 with 300 rpm by the crown-down preparation technique. Pre- and post-instrumentation apical foramen images were overlapped and recorded with Image-analyzing microscope 100X (Camcope, Sometech Inc, Korea). The amounts of difference in width and dimension on overlapped images were measured after reference points were determined by Image Analysis program (Image-Pro(R) Express, Media Cybernetic, USA). Data were analyzed using Kruskal-Wallis and Mann-Whitney U-test. The results suggest that ProFile showed significantly less canal transportation and maintained original apical foramen shape better than K3 and ProTaper.
Cybernetics ; Dental Pulp Cavity ; Tooth Apex* ; Transportation*

The aim of this study was to investigate the shapes and diameters of the physiological foramen and anatomy of the root canal at 3mm from apex in mandibular first molars. Sixty mandibular first molars were randomly selected. The apical anatomy of 60 mandibular first molars was investigated by means of a stereomicroscope (60x magnification). The results were as follows; 1. There was a high percentage of two physiological foramina in mesial (61.67%) and one foramen in distal(71.66%) roots of mandibular first molars. 2.There was a high frequency of accessory foramina in mesial roots with one foramen (26.07%). 3. The diameters of physiological foramen was as follows: 0.329mm in single mesial foramen. 0.266mm in mesiobuccal foramen and 0.246mm in mesiolingual foramen. 0.375mm in single distal foramen. 0.291mm in distobuccal foramen and 0.237mm in distolingual foramen. 4. The most common physiological foramen shape was oval (69.93%). 5. The incidence of isthmus in mesial root at 3mm from apex was 55%. The 3mm-sections contained a complete isthmus 31.66% and a partial isthmus 23.34%. 6. 3mm from the apex, the most common canal shape was oval (50.64%). Knowledge of the apical anatomy of mandibular first molar would be necessary for success of surgical and nonsurgical endodontic treatment.
Dental Pulp Cavity ; Incidence ; Molar ; Tooth Apex

The purpose of this study was to investigate influence of each file step of ProTaper(R) system on canal transportation. Twenty simulated canals were prepared with either engine-driven ProTaper(R) or manual ProTaper(R). Group R-resin blocks were instrumented with rotary ProTaper(R) and group M-resin blocks were instrumented with manual ProTaper(R). Pre-operative resin blocks and post-operative resin blocks after each file step preparation were scanned. Original canal image and the image after using each file step were superimposed for calculation of centering ratio. The image after using each file step and image after using previous file step were superimposed for calculation of the amount of deviation. Measurements were taken horizontally at five different levels (1, 2, 3, 4 and 5 mm) from the level of apical foramen. In rotary ProTaper(R) instrumentation group, centering ratio and the amount of deviation of each step at all levels were not significantly different (p > 0.05). In manual ProTaper(R) instrumentation group, centering ratio and the amount of deviation of each step at all levels except of 1 mm were not significantly different (p > 0.05). At the level of 1 mm, F2 file step had significantly large centering ratio and the amount of deviation (p < 0.05). Under the condition of this study, F2 file step of manual ProTaper(R) tended to transport the apical part of the canals than that of rotary ProTaper(R).
Dental Pulp Cavity* ; Tooth Apex ; Transportation

The final preparation (MAF) size in infected root canals is still controversial. Nonetheless, recent studies demonstrated that larger apical preparation sizes produces a greater reduction in remaining bacteria and dentinal debris as compared to smaller apical preparation sizes. Therefore, clinicians should be practiced with treatment strategies guided by evidence-based information, especially in infected/failed root canals.
Bacteria ; Dental Pulp Cavity ; Dentin ; Tooth Apex

In order to achieve a successful endodontic treatment, root canals must be obturated three-dimensionally without causing any damage to apical tissues. Accurate length determination of the root canal is critical in this case. For this reason, I've used the conventional periapical radiography, Digora(R)(digital imaging system) and Root ZX(R) (the frequency dependent type apex locator) to measure the length of the canal and compare it with the true length obtained by cutting the tooth in half and measuring the length between the occlusal surface and the apical foramen. From the information obtained by these measurements, I was able to evaluate the accuracy and clinical usefulness of each systems, whether the thickness of files used in endodontic therapy has any effect on the measuring systems was also evaluated in an effort to simplify the treatment planning phase of endodontic treatment. 29 canals of 29 sound premolars were measured with #15, #20, #25 files by 3 different dentists each using the periapical radiography, Digora(R) and Root ZX. The measurements were then compared with the true length. The results were as follows ; 1. In comparing mean discrepancies between measurements obtained by using periapical radiography(mean error : -0.449+/-0.444 mm), Digora(R)(mean error : -0.417+/-0.415 mm) and Root ZX(R) (mean error : 0.123+/-0.458 mm) with true length, periapical radiography and Digora(R) system had statistically significant differences(p<0.05) in most cases while root zx showed none>0.05). 2. By subtracting values obtained by using periapical radiography, Digora(R) and Root ZX(R) from the true length and making a distribution table of their absolute values, the following analysis was possible. In the case of periapical film, 140 out of 261(53.6%) were clinically acceptable satisfying the margin of error of less than 0.5 mm, 151 out of 261(53,6%) were acceptable in the Digora(R) system while Root ZX(R) had 197 out of 261(75.5%) within the limits of 0.5 mm margin of error. 3. In determining whether the thickness of files has any effect on measuring methods, no statistically significant differences were found(p>0.05). 4. In comparing data obtained from these methods in order to evaluate the difference among measuring methods, there was no statistically significant difference between periapical radiography and Digora(R) system(p>0.05), but there was statistically significant difference between Root ZX(R) and periapical radiography(p<0.05). also, there was statistically significant difference between Root ZX(R) and Digora(R) system(p<0.05). In conclusion, Root ZX(R) was more accurate when compared with the Digora(R) system and periapical radiography and seems to be more effective clinically in determining root canal length. But Root ZX(R) has its limits in determining root morphology and nember of rootd and its accuracy becomes questionable when apical foramen is open due to unknown reasons. Therefore the combined use of Root ZX(R) and the periapical radiography are mandatory. Digora(R) system seems to be more effective when periapical radiographs are needed in a short period of time because of its short processing time and less exposure.
Bicuspid ; Dental Pulp Cavity* ; Dentists ; Humans ; Radiography ; Tooth ; Tooth Apex