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At least 415 records · Page 23Linked to original sources
PubMed1998

Air pressures developed beyond the apex from drying root canals with pressurized air.

Air introduced into tissues during invasive procedures can be harmful. Endodontic treatment is not frequently associated with this phenomenon, but serious results can occur if air forced into tissues impinges on critical anatomical structures and/or carries infection into deeper areas. Extracted teeth were connected to a pressure gauge during and after canal instrumentation and pressures measured. Also, a fresh porcine jaw was instrumented in the presence of a radiopaque tracer during air drying. Significant pressures were detected beyond the apex of the roots, especially with root apical diameters of file sizes larger than 20.

Air Pressure↗
PubMedDate not supplied

A case of stapler pin in the root canal--extending beyond the apex.

There have been several reports describing the placement, by patients, of foreign objects into exposed pulp chambers and canals. In the present case, a 13-year-old patient reported with complaints of pain and a history of inserting a foreign object into the root canal of the left central incisor. On examination the foreign body was found to be a stapler pin which was projecting 5 millimeters from the apical foramen. Foreign bodies discovered from the root canal have varied from radiolucent objects like wooden tooth picks or tooth brush bristles to radioopaque materials like paper pins, needles, pencil leads etc. In the present case, despite our best efforts, the patient did not agree to undergo any treatment except for the extraction of the left central incisor.

Adolescent↗
PubMed2001

The standardized-taper root canal preparation--Part 4. GT file technique in large root canals with large apical diameters.

AIM: To describe the GT file shaping steps required to create apical resistance in the presence of a wide root apex. SUMMARY: Canals are occasionally encountered with apices wider than 0.25 mm. These can be some of the most difficult to manage with conventional instruments, and overfills are common. Shaping such canals with GT files requires a paradigm shift of thinking, extending tapered files through the apex to create linear resistance in the apical few mm of the canal. GT standard and accessory files allow canals with apices up to around 0.7 mm to be prepared for tapered gutta percha cone-fit. Apices larger than this should be considered too large for further shaping, and repaired with MTA before filling. KEY LEARNING POINTS: Tapered apical preparations offer optimal resistance form for obturation. Tapered apical preparations can be prepared in most roots with wide apices by extending GT files and GT accessory files to or through the apex. Apices wider than 0.7 mm should be repaired with MTA prior to filling.

Aluminum Compounds↗
PubMed2002

The effect of an apex locator on exposure to radiation during endodontic therapy.

The objective of this study was to investigate whether the use of an electronic apex locator results in a reduction in X-ray exposure during endodontic therapy. Fifty, sound, extracted, single-rooted canine and incisor teeth were selected and randomly divided into two groups (A and B) of 25 teeth. The working length was determined radiographically with (group B) and without (group A) adjunctive use of an apex locator by one operator. After working length determination, the teeth were sectioned and the actual working length measured for comparison. For group A, 14 retake radiographs were required to determine the working length, whereas group B required no retake radiographs; this difference was highly significant (p < 0.001). The electronic apex locator was extremely accurate in locating the apical foramen with all teeth tested within 0.5 mm of the anatomical apex and 11 (44%) teeth at the apical foramen. In contrast, 15 (60%) teeth tested using radiographs alone were within 0.5 mm of the anatomical apex and only 4 (16%) teeth were actually at the anatomical apex. It was concluded that using an electronic apex locator as an aid to endodontic therapy could potentially reduce the number of diagnostic radiographs required for working length determination. Location of the apical foramen using a combination of an electronic apex locator and radiographs to determine working length is more accurate than using radiographs alone.

Chi-Square Distribution↗
PubMed2005

Validating the roles of apex locators and sonic instrumentation in root canal therapy.

Paramount to the success of endodontic therapy is determining the working length of the canal and, subsequently, effectively cleaning and irrigating the canal. Electronic apex locators and sonic instrumentation can help overcome some of the clinical and practical challenges inherent in endodontic treatment. This article reviews literature findings regarding the applications of apex locators and sonic instrumentation to more accurately determine working length and enhance canal preparation and irrigation. A clinical technique is presented for completing canal preparation and irrigation using sonics.

Dental Pulp Cavity↗
PubMed1999

[Electronic determination of the length of the root canal].

The endpoint of an endodontic treatment must be situated at the cemen-to-dentinal junction to preserve the biological potential of the periapical area and to realize a complete disinfection of the principal root canal system. Thus, the determination of working length is a crucial factor in endodontic therapy. The conventional radiographic method cannot provide the accurate location of the apical constriction. For this reason, the electronic apex locators have been developed. Now, the last generation of apex locators has become more sophisticated and the electronic measurements seem to be accurate and reliable with electrolytic solutions in the canal.

Dental Pulp Cavity↗
PubMed2004

Endodontic treatment of dens invaginatus type III with three root canals and open apical foramen.

AIM: To describe the conservative endodontic treatment and the 1-year follow-up of a permanent maxillary lateral incisor with dens invaginatus. SUMMARY: Frequently, the root canal treatment of invaginated teeth is challenging because of problems associated with gaining access to the root canals and with variations of canal morphology associated with this type of malformation. The present case describes the complex root canal treatment of dens invaginatus in a maxillary lateral incisor with three root canals (Oehler type III), incomplete apex formation, necrotic pulp and abscess formation. After gaining access to two root canals and the invagination with the help of a dental operating-microscope, the canals and the invagination were instrumented and calcium hydroxide dressing was applied for 6 months. Apexification and osseous bone repair were achieved, and the canals were filled with gutta-percha. A follow-up after 1 year showed that the tooth was free of any clinical symptoms and the periapical condition was normal. KEY LEARNING POINTS: The present case demonstrated that conservative root canal treatment can be performed successfully even in sever cases of dens invaginatus. The use of a dental operating microscope can help in the management of complicated cases of invaginated teeth through conventional root canal treatment.

Child↗
PubMed2000

Effect of using electronic apex locators on selected endodontic treatment parameters.

The purpose of this study was to determine the effect of using electronic apex locators on the number of radiographs taken and the adequacy in length of the final obturation. Patients in an undergraduate student endodontics clinic participated in the study. The working length (WL) was estimated by the authors for all cases (36 teeth; 58 canals), using both a preoperative standardized radiograph and an electronic measurement. The students were then asked to place WL files to one of the estimates (electronic or radiographic; chosen by random assignment) and take a WL radiograph. Neither the students nor their instructors knew which method was chosen for the estimates. Once treatment was completed, the total number of working radiographs was counted. The number of cases with acceptable (0 to 2 mm short of the apex) or unacceptable obturation was also blindly registered. An electronic estimate of the WL improved length quality of the final obturation, compared with a radiographic estimate. The number of working radiographs taken was less in the electronic apex locator group in anterior and premolar teeth, but not in molars.

Adult↗
PubMed1996

An in vivo evaluation of Root ZX electronic apex locator.

The Root ZX has been introduced recently as a device capable of performing accurately in the presence of sodium hypochlorite, blood, water, local anesthetic, and pulpal tissues. The Root ZX was used to locate the apical foramen in 26 root canals of vital teeth. After extraction of the teeth, a stereomicroscope was used to confirm visually the relationship of the tip of the endodontic file to the apical foramen. The Root ZX located exactly the apical foramen in 17 canals (65.4%), was short in 1 canal (3.8%), and was overextended in 8 canals (30.8%). When a potential error of +/-0.5 mm from the foramen is accepted as a tolerable range for the clinical application of an electronic apex locator, the Root ZX was able to locate the foramen within this range in 25 teeth for a clinical accuracy rate of 96.2%.

Dental Instruments↗
PubMed2001

Anesthetic efficacy of infiltrations in mandibular anterior teeth.

The purpose of this prospective, randomized, double-blind study was to measure the degree of anesthesia obtained with a labial infiltration of either 2% lidocaine with 1:50,000 or 2% lidocaine with 1:100,000 epinephrine in mandibular anterior teeth. Another objective was to measure the degree of anesthesia obtained with a lingual infiltration of 2% lidocaine with 1:100,000 epinephrine in mandibular anterior teeth. Through use of a repeated-measures design, 40 subjects randomly received a labial infiltration at the lateral incisor apex of either 1.8 mL of 2% lidocaine with 1:100,000 epinephrine or 1.8 mL of 2% lidocaine with 1:50,000 epinephrine at 2 separate appointments. An additional 40 subjects received a lingual infiltration at the lateral incisor apex of 1.8 mL of 2% lidocaine with 1:100,000 epinephrine. The mandibular anterior teeth were blindly pulp tested at 4-minute cycles for 60 minutes postinjection. No response from the subject to the maximum output (80 reading) of the pulp tester was used as the criterion for pulpal anesthesia. Anesthesia was considered successful when 2 consecutive 80 readings were obtained. For the 3 infiltrations, success rates for the lateral incisor ranged from 43 to 50%. Adjacent teeth had success rates of 27 to 63%. There was no significant difference (P > 0.05) in success between the labial infiltration of 2% lidocaine with 1:100,000 epinephrine and 2% lidocaine with 1:50,000 epinephrine or the lingual infiltration of 2% lidocaine with 1:100,000 epinephrine when compared with the labial infiltration of 2% lidocaine with 1:100,000 epinephrine. Duration of pulpal anesthesia declined steadily for all solutions over the 60 minutes. In conclusion, the success rate of 43-50% and declining duration of pulpal anesthesia over an hour indicates that a labial infiltration of 1.8 mL of either 2% lidocaine with 1:100,000 epinephrine or 1: 50,000 epinephrine or a lingual infiltration of 2% lidocaine with 1:100,000 epinephrine over the lateral incisor apex cannot be recommended clinically to provide profound pulpal anesthesia.

Adult↗
PubMed2005

A comparison between two electronic apex locators: an in vivo investigation.

AIM: To compare in vivo the Apex Finder and Root ZX electronic apex locators (EALs) at five different stages during root canal instrumentation. METHODOLOGY: The Apex Finder and Root ZX were used in 64 teeth with either vital or necrotic pulps. Informed consent was obtained by each patient under a study protocol approved by an ethical committee from the University of Trieste. Measurements were made: (stage 1) before instrumentation and irrigation; (stage 2) after brief filing, irrigation with 70% isopropyl alcohol and partial drying; (stage 3) after canal lubrication with EDTA gel (RC-Prep); (stage 4) after complete instrumentation and irrigation with NaOCl 5%; (stage 5) after drying of the final instrumented canal. Stages 2, 3 and 5 were considered low canal conductivity conditions and stage 4 as high. Teeth were then extracted and a size 15 K-file was inserted until its tip was observed under stereomicroscope to reach the foramen and the corresponding length was recorded to an accuracy of 0.25 mm and compared with values derived from the EALs. RESULTS: The data revealed 133 unstable measurements (out of 640): some (68) related to low canal conductivity conditions (more frequently for Root ZX, 67; P < 0.05), and others (63) related to NaOCl presence in the canal (more frequently for Apex Finder, 58; P < 0.05). Accuracy was calculated only on stable measurements. The Root ZX showed significantly (P < 0.05) more precise measurements overall (-0.03 +/- 0.39 mm) compared with the Apex Finder (-0.31 +/- 0.46 mm). Under dry canal conditions the Apex Finder provided the greatest accuracy (-0.0 +/- 0.21) compared with the Root ZX (-0.05 +/- 0.32) (significance P < 0.05). CONCLUSIONS: Under the five different clinical situations both EALs revealed accurate measurements. Apex Finder was negatively influenced by NaOCl in the root canal. The Root ZX was more frequently unable to reveal stable measurements in low conductivity canals.

Analysis of Variance↗
PubMed2007

In vivo comparison of working length determination with two electronic apex locators.

AIM: To compare the accuracy of two electronic apex locators (EALs) in the same teeth in vivo. METHODOLOGY: The working lengths in 20 teeth with a single canal were determined with two different EALs (Root ZX; J. Morita Corporation, Tokyo, Japan and Raypex 5 VDW, Munich, Germany) before extraction. When the first EAL was used the files were advanced until the display indicated the 'apical constriction'. The files were then fixed in removable and replaceable light curing composite patterns. The procedure was repeated in the same tooth with the second EAL and a different file. The teeth were then extracted and the apical 4 mm of the root canals were exposed. After that the apical parts with the repositioned files in the canals were digitally photographed under a light microscope. On the images the minor diameter and the major foramen of each sample were marked and the respective distances of the file tips from these positions were measured with a computer program. Subsequently the values of the two groups of EALs were compared using a paired sample t-test. RESULTS: The minor foramen was located within the limits of +/-0.5 mm in 75% of the cases with the Root ZX and in 80% of the cases with Raypex 5. The paired sample t-test showed no significant difference between the EALs regarding determination of the minor foramen. CONCLUSION: The use of EALs is a reliable method for determining working length. The differences between the two EALs were not statistically significant.

Adult↗
PubMed2004

Perforation risks associated with the use of Masserann endodontic kit drills in mandibular molars.

PURPOSE: The use of Masserann kit is a frequently recommended technique for the removal of canal obstructions. Although this technique is usually successful, it may cause excessive removal of dentin tissue in root canals. The aim of this study is to evaluate the perforation risk and the remaining dentin thickness in mesial canals of mandibular molars following the use of Masserann kit. STUDY DESIGN: Fifty-three extracted human mandibular molars were selected for the study. The teeth were separated into 3 groups based on the degree of curvature of the root canals. By using Radio Visio Graphy and Coral Draw 8.0 software packages, the dentin/cement thickness of root canal was measured before and after the use of Masseran kit drills. RESULTS: In the severely and moderately curved mesial root of mandibular molars, the Masserann Kit increased the risk of creating thin or perforated walls. Additionally, after 7.5mm depth of drilling, the percentage of perforations increased in all groups. CONCLUSIONS: With respect to endangering the dentinal walls towards the apex of root canals, Masserann kit drills were found to increase the risk of perforations in curved canals and in deep preparations.

Chi-Square Distribution↗
PubMed2003

Endodontic infection: some biologic and treatment factors associated with outcome.

OBJECTIVE: We sought to investigate the simultaneous effect of apical periodontitis, instrumentation level, and density of root canal filling on endodontic treatment outcome. METHODS: For this study, 200 endodontically treated teeth with 441 roots were used. A follow-up examination was conducted 4 +/- 0.5 years postoperatively. Data were subjected to univariate and multivariate analysis. RESULTS: Periapical pathosis had the strongest effect on treatment outcome (P <.0001). The instrumentation level (mean +/- SEM of the working length) for successfully treated teeth/roots with normal preoperative pulp and periapex was farther away from the radiographic apex (1.23 +/- 0.13 mm) than for teeth/roots with an unsuccessful outcome (0.20 +/- 0.09 mm; P <.005). However, successfully treated teeth/roots with pulp necrosis and apical periodontitis had working length levels closer to the radiographic apex (0.55 +/- 0.12 mm) than did teeth/roots with unsuccessful outcomes (1.73 +/- 0.30 mm; P<.001). In teeth/roots with apical periodontitis, a millimeter loss in working length increased the chance of treatment failure by 14%. The risk of failure was higher for a fair/poor density of obturation than for a good density for all diagnoses of periradicular status. CONCLUSION: Diseased periapex, level of working length relative to the radiographic apex, and fair/poor density all affect the outcome of endodontic treatment.

Analysis of Variance↗
PubMed2004

Morphology of root canal cross-sections of resected roots of first and second lower molars.

Precise preparation of the root canal ostium with a view to hermetical closing with retrograde root filling is an important prognostic factor determining the success of the procedure of tooth resection. Root canals interconnected with a narrow isthmus may cause problems both in endodontic treatment and in retrograde filling. The aim of this work is the research of the transverse cross-section of root canals of first and second lower molars on the resection model. The research encompasses 100 randomly selected molar teeth: 50 first and 50 second lower molars. The tooth root apexes were cut 3 mm below the apex and examined under an electron microscope, special attention being paid to the shape of root canal cross-sections. In the group of first molar teeth, in 20% the presence of an isthmus between canals in the proximal roots was observed; in the group of second molar teeth an isthmus between the canals of proximal roots occurred in 18% of the cases. It seems that the relatively high percentage (20%-18%) of the occurrence of an isthmus, 3 mm below the root apex, between two elongated transverse cross-section proximal root canals of first and second molars should encourage particular caution in the retrograde filling of the above-mentioned canals during the procedure of resection.

Dental Pulp Cavity↗
PubMed2002

Temperature change within gutta-percha induced by the System-B Heat Source.

AIM: This study evaluated the temperature change within gutta-percha during the vertical compaction technique performed with a System-B Heat Source. METHODOLOGY: Extracted human teeth were prepared and divided in two equal groups depending on the apex diameter (group 1: 0.20-0.25 mm and group 2: 0.30-0.35 mm). Teeth were root treated with a combination of step-back and coronal flaring instrumentation using Gates Glidden burs and hand stainless steel K- and H-files. Two thermocouples were connected to the outer surface of the root: the first one was placed 2 mm apically from cement-enamel junction (CEJ) (point C); and the second one 1.5 mm from the apex (point A). The instrumented canals were filled with size F gutta-percha cones. All teeth were then immersed in a thermostatic bath at a constant temperature of 37 degrees C and warm vertical compaction was performed using a System-B Heat Source. delta T values were recorded by means of a digital thermometer connected to the thermocouples. RESULTS: Increments of temperature (delta T) recorded in point A revealed a mean value of 0.5 +/- 0.5 degree C for group 1 and 0.9 +/- 1.1 degrees C for group 2; delta T values recorded at point C gave a mean value of 4.1 +/- 1.7 degrees C for group 1 and 3.9 +/- 1.81 degrees C in group 2. No statistical difference was found between the groups, whilst a difference was present between the measurements at points A and C (P < 0.01). CONCLUSIONS: The use of the System-B Heat Source on root canals maintained at a constant body temperature by a thermostatic bath revealed that the increase of temperature of the gutta-percha at the apical third of the canal was negligible and that the compaction of the mass of the gutta-percha close to the apex was performed at body temperature. Minor changes in temperature of the outer surface of the root canals occurred, suggesting no danger for the periradicular tissues.

Analysis of Variance↗
PubMed2004

Evaluation of the antimicrobial effect of Er:YAG laser irradiation versus 1% sodium hypochlorite irrigation for root canal disinfection.

This laboratory study evaluated Er:YAG laser antibacterial action in infected root canals. Forty-eight maxillary central incisors were used. After canal preparation, the teeth were autoclaved and divided into four groups: (1) non-treated teeth (control group); (2) teeth treated with NaOCl; (3) teeth irradiated with Er:YAG laser (7 Hz, 100 mJ, 80 pulses/canal, 11 sec) to the working length; (4) teeth irradiated similarly to, but 3 mm short, of the apex. The root canals from Groups 2, 3 and 4 were inoculated with 4 bacteria: Bacillus subtillus, Enterococcus faecalis, Pseudomonas aeruginosa, and Staphylococcus aureus, together with Candida albicans, and maintained for 24 h at 37 degrees C. All suspensions were adjusted to tube 2 of the MacFarland scale. The intracanal material was then collected with sterile paper points, which were placed in the canals for 5 min and then immersed in 5 ml of BHI medium. This was then seeded onto agar and stained by Gram's method. The NaOCl solutions and the Er:YAG laser irradiation to working length were effective against all five micro-organisms; however, 70% of the specimens irradiated 3 mm short of the apex remained infected.

Aluminum Silicates↗