Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Root Canal Preparation”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 19 recordsLinked to original sources
PubMed1995

[In vitro comparison of instruments for root canal preparation. III. Study of the instruments from the viewpoint of shaping asymmetry].

The shape of the prepared root canals is not consistent with the original anatomical shape in the majority of curved canals. The discrepancy is dependent of the type of instrument, the original anatomical form of the root canal and the location of the measurement. The original shape of the root canal has to be taken into consideration in the selection of preparatory instruments because their application is limited by the above mentioned factor. The sonic and ultrasonic preparatory instruments form an exception in this respect due to their non aggressive way of shaping. These instruments cannot be disregarded in the preparation of curved root canals.

Dental Instruments↗
PubMed2000

The effect of root canal preparation on microleakage within endodontically treated teeth: an in vitro study.

AIM: The purpose of this study was to evaluate the effects of smear layer and canal instrumentation on leakage in root-filled teeth. METHODOLOGY: Six groups (n = 12) of freshly extracted human canines and premolars with closed apices and single roots were used. Groups A, B, C, and D were instrumented with engine-driven rotary nickel-titanium MCXIM files and Groups E and F were instrumented with conventional stainless steel hand files. Groups A, C, and E were flushed with 3.0 mL of 17.0% REDTA to remove the smear layer prior to obturation. All teeth were flushed with 5.25% NaOCl, then obturated with AH-26 sealer and either the lateral condensation (Groups C-E) or thermomechanical compaction technique (Groups A and B). Copper wire was placed coronally in contact with the gutta-percha in each tooth and, after immersion in 0.9% NaCl solution, a 10 volt dc voltage was connected between each tooth and a stainless steel electrode. The current flow in the circuit was observed for 45 days. One way ANOVA and Duncan's Multiple Range Test were used to compare Groups A-F at time intervals of 10, 20, 30 and 45 days and identify statistically significant differences. RESULTS: Significantly less microleakage occurred when the smear layer was removed and when the canals were obturated with thermoplasticized gutta-percha. Canals instrumented with engine-driven NiTi files exhibited less leakage than hand-instrumented canals irrespective of obturation method. CONCLUSIONS: Smear layer removal is beneficial to root canal sealing. Obturation with thermoplasticized gutta-percha provides a superior seal whilst canal instrumentation with engine-driven NiTi files reduces the extent of microleakage in root canals.

Analysis of Variance↗
PubMed1997

Effect of tip design of nickel-titanium and stainless steel files on root canal preparation.

The purpose of this study was to evaluate the effect of modified and non-modified tip designs of both stainless steel and nickel-titanium endodontic hand files on root canal preparation. Root canals of mesial roots of extracted mandibular molars were prepared using a quarter-turn-pull technique. The experimental design permitted comparison of the effects of nickel-titanium alloy construction or file tip modification alone, with effects when these two factors were incorporated into a single file design. Transportation, centering ratio, and dentin removal were evaluated using a modified Bramante technique. Nickel-titanium files, regardless of tip design, remained significantly more centered and demonstrated less apical transportation than stainless steel files at size 25. When instrumentation was continued to size 40 apically with step-back, there were no significant differences in transportation in the apical or coronal sections. However, during instrumentation to size 40 with step-back, the combination of modified tip and nickel-titanium alloy produced significantly more transportation and dentin removal, as well as greater deviation from the center at the mid-root level than did other file designs. Thus, of the file design parameters evaluated in this study, construction from nickel-titanium was most important in defining canal configuration at small file sizes in the apical region. Although the combination of nickel-titanium and modified tip design resulted in more transportation at larger file sizes in the midroot region, such alterations in canal configuration may be of little importance clinically. Nonetheless, it is suggested that other factors, such as tactile sensation and instrumentation technique, should be considered as important as the type of alloy or tip design.

Analysis of Variance↗
PubMed1996

[In vitro comparative study of instruments for root canal preparation. IV. Correlations between the original shape of the root canal and the asymmetry resulting from the preparation].

Certain asymmetry of root canal preparation can be observed in the straight root canal group, as well. The modification of original root canal shape in this group usually is not substantial. Using hand instruments for shaping curved canals special tecniques are required to minimize the asymmetry. Though tendencies of different shaping characteristics can be observed on the mesiodistal and oro-vestibular views there are no statistically significant differences between the asymmetries measured on the oro-vestibular and mesio-distal views. The three dimensional form of canals usually exclude the possibility of forming the same asymmetry on both projections, but the difference between the two views is not striking, therefore the conventional clinical radiographs usually do not give complete information about the asymmetry of preparation.

Dental Instruments↗
PubMed2001

The standardized-taper root canal preparation--Part 3. GT file technique in large root canals with small apical diameters.

AIM: To describe the preparation of Large Root canals with small apical diameters by the GT file technique. SUMMARY: Large Root canals with small apical diameters can usually be prepared with one to three GT files; one to nine clinical steps, and one to five minutes of clinical time. Following proper access, pulp tissue should be removed, and lubricant applied to prevent pulp compaction and blockage. Initial crown-down enlargement is accomplished with up to three standard GT rotary files 0.10, 0.08 and 0.06 taper, running at 300 r.p.m., and with light touch. Care should be taken not to overload instruments, and they should be withdrawn, cleaned and inspected whenever they bind. Sometimes, the shaping objective is achieved with a single instrument; often waves of instrumentation are required before the shaping objective file cuts to length. Prior to cone-fit, the apical resistance form is confirmed with conventional files, employed as feeler gauges of the tapering form created at the canal terminus. Regardless of the shaping time, canals should be soaked with sodium hypochlorite solution for at least 30 min for effective cleaning. KEY LEARNING POINTS: Large Root canals with small apical diameters should be prepared to shaping objectives 0.08 or 0.10 taper. Compacted pulp tissue causes many canal blockages. It should be removed early, and canals should be well lubricated. Large Root canals with small apical diameters should be prepared in crown-down sequence, with recapitulation of steps until the shaping objective is achieved. Apical resistance form should always be confirmed before cone-fit. Canals should be exposed to sodium hypochlorite for at least 30 min for effective cleaning.

Dental Pulp Cavity↗
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↗
PubMed1992

A comparison in vitro of two ultrasonic root canal preparation techniques.

Two ultrasonic techniques were compared for their ability to clean and shape root canals in extracted human teeth. One technique was recommended by the manufacturer (Cavi-Endo, Dentsply), while the other was a modification by the authors of the stepdown technique. Mesiobuccal root canals of molars were instrumented using these techniques, after which a silicone impression material was injected into the prepared canals. The roots were then split longitudinally and one half was stained for debris scoring while the silicone impressions were assessed for shape. The results showed that the modified technique produced significantly cleaner canals than the recommended technique. The shaping ability of both techniques was difficult to evaluate because of the complex morphology of molar root canals. The final shape of the prepared canal depended more on the initial shape than on the instrumentation technique.

Dental Cavity Preparation↗
PubMed1989

An in vitro method for comparing the effects of different root canal preparation techniques on the shape of curved root canals.

This study introduced an in vitro model which was designed to observe the effects of instrumentation on the shape of curved root canals. The model may be accurately rotated through 90 degrees allowing reproducible radiographs to be taken from two different angles. The root canals were filled with a radiopaque contrast medium before radiographs were taken. Two-dimensional evaluation of the shape of the root canals, before and after preparation was made on enlarged photographic prints obtained from the radiographs. A custom-made grid was used as a guide for measurement and accurate transfer from the pre- to postpreparation prints. Reproducibility of measurement was within 4 per cent. This method is feasible for quantitative comparison of the effect of instrumentation on the shape of root canals.

Dental Pulp Cavity↗
PubMed1989

[SEM studies on root canal preparation using ultrasound].

The root canals of 35 extracted mandibular incisors were instrumented with the ultrasonic-system alone or in combination with hand instruments. Hand instrumentation was compared with ultrasonic instrumentation. Following instrumentation the teeth were prepared for SEM examination. It was concluded that hand instrumentation using reamers was superior to ultrasonic debridement. After initial preparation and finally shaping with hand instruments the ultrasonic device shows good efficiency in cleaning straight root canals.

Dental Pulp Cavity↗
PubMed1989

[Root canal preparation using Excimer laser beams].

An in vitro investigation of root canal preparation on extracted human teeth by 308 nm Excimer Laser radiation was performed. It could be demonstrated that a secure and effective root canal preparation is possible by Excimer Laser radiation. SEM investigations on axially splitted roots showed root canal walls free of smear layer or any other soiling. The dentin-tubuli where open and free of clogging. There was no case of via falsa or overinstrumentation.

Evaluation Studies as Topic↗
PubMed1999

An improved technique for the evaluation of root canal preparation.

A device and a method are described for the simultaneous in vitro evaluation of several important parameters of root canal preparation, including root canal cleanliness, straightening, changes in root canal diameter, working safety (loss of working length, apical blockage, instrument fracture, and apical perforation), measurement of apically extruded debris, working time, and practicability. Using a modification of the muffle system described by Bramante et al. (J. Endodon, 13:243-5, 1987), all of these parameters can be investigated simultaneously during preparation of two mesial root canals in extracted mandibular molars.

Evaluation Studies as Topic↗
PubMed1989

[Root canal preparation with Canal-Finder system. Scanning electron microscopy and clinical studies].

Root canal preparation was performed with the new Canal-Finder-System in extracted teeth and in simulated root canals in resin blocks. The results of SEM- and stereomicroscopic investigation showed severe alterations of root canal morphology in the apical part of the canal in many cases. Excellently cleaned and shaped canal walls were found as well as parts, which were not instrumented at all or covered with smear layer and debris. The Canal-Finder-System was found to be a good and suitable device for the initial instrumentation of narrow and severely curved canals, but cannot replace hand instrumentation as the standard method of root canal preparation.

Dental Pulp Cavity↗
PubMed1992

Effect of noncutting tipped instruments on the quality of root canal preparation using a modified double-flared technique.

Fifty-one extracted human first molar teeth with intact crowns and mature root apices were divided into three groups. Root curvature was determined. One of the root canals in the mesial root of lower molars, or the mesiobuccal root in maxillary molars, was prepared in one of three ways. In group 1 the root canals were instrumented using a modified double-flared technique with noncutting tipped files (Flex R); in group 2 the same files were used with a step-back technique. Group 3 was prepared with conventionally tipped files (K-Flex) using the step-back technique. A low viscosity polyvinyl siloxane impression material was injected into the prepared root canals and the specimens were decalcified, dehydrated, and cleared. The preparation was evaluated subjectively according to various desirable or undesirable criteria. A rating for overall quality of preparation was given. Statistical analysis showed that the teeth in group 1 had better overall preparation than those in group 3 (p < 0.05). There were no other statistically significant differences between the groups. The mean time required for each preparation technique was not statistically significantly different (p > 0.1). The use of a modified double-flared technique with non-cutting tipped files was shown to be an effective method for the preparation of curved root canals.

Analysis of Variance↗