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In vitro comparison of root-canal measurements with conventional and digital radiology.

AIM: The present study compared the efficacy of digital and conventional radiology for root-canal length measurement. METHODOLOGY: Seventy extracted teeth with pre-served roots were used. Root-canal length measurements were completed with K-Flexofiles (numbers 08, 10 and 15) with conventional and digital radiography using two systems (radiovisiography and photostimulate storage phosphor). All films and sensors were exposed at projections of 0 degrees and 20 degrees to the mesial. The images obtained were evaluated with and without magnification, and analysed using the Cohen's kappa test. The accuracy of the three systems to determine the root-canal length were evaluated by measuring the distance from the tip of the file to the apex. RESULTS: Most of the values corresponding with the apex occurred with conventional radiology. The digital systems yielded negative values that improved with a size 15 file. The agreement between the two digital systems was the best with size 15 file using 0 degrees projection (66.7%). CONCLUSIONS: Conventional radiology remains the technique of choice in determining the root-canal length; the digital techniques yielded good results for size 15 file.

Dental Pulp Cavity↗

Biologic perspectives to support clinical choices in root canal treatment.

Some of the most keenly debated issues in endodontics have revolved around the where to end the root filling, as well as cleaning and shaping and obturation techniques. In some respects, original scientifically-based concepts have been abandoned in favour of clinical techniques that may provide aesthetically pleasing radiographs, but do not necessarily support tissue regeneration around the root apex following obturation. Recently advocated obturation techniques supporting the use of resin-based and bonded materials have not had the same extensive evaluation that gutta-percha, when in contact with the periradicular tissues, has had. Further studies are necessary so that evidence-based data can support the confident use of these innovative materials.

Extravasation of Diagnostic and Therapeutic Materi↗

[Alternatives to radiography for determining root canal length].

Location of the apical foramen using an electronic apex locator to determine working length is more accurate than using radiographs alone. The Neosono Co-pilote is not adversely affected by the presence of sodium hypochlorite and gives us acceptable results in dry canals. Hence, it is today possible to realize endodontic treatment without X ray determination.

Adult↗

Comparison of the first file that fits at the apex, before and after early flaring.

The purpose of this study was to compare the first file that fits to the apex (FFFA) in each canal before and after early flaring to analyze if the size of file to fit to the apex would increase after flaring. One hundred mesial canals of lower first and second molars with complete apical formation and patent foramens were selected. The samples were randomly divided into two groups of 50 canals each. A file was fit to the apex in each canal and that size recorded. Radicular flaring was completed using Gates-Glidden drills in group 1 and Rapid Body Shapers in group 2. After flaring a file was again fit to the apex in the same manner as before and its size recorded. The mean diameter of FFFA before flaring (file diameters in mm x 10(-2)) was 14.46 (+/-4.12) and after 23.3 (+/-7.2) for group 1 (p < 0.001), whereas in group 2 the mean diameter of FFFA was 17.2 (+/-4.96) before and 25.6 (+/-6.36) after (p < 0.001). A Wilcoxon t test indicates a significant difference (p < 0.001) between the diameter of FFFA before and after flaring in both groups. The increase in diameter was approximately two file sizes for both groups. From this observation it is concluded that early radicular flaring increases the size file that is snug at the apex, and awareness of that difference gives the clinician a better sense of canal size. Early flaring of the canal provides better apical size information and with this awareness, a better decision can be made concerning the appropriate final diameter needed for complete apical shaping.

Anti-Infective Agents, Local↗

The use of an ultrasonic technique to remove a fractured rotary nickel-titanium instrument from the apical third of a curved root canal.

The frequency of use of nickel-titanium rotary instruments in endodontic practice is increasing. One occasionally mentioned problem is fracture of an instrument within the root canal. The broken instrument may prevent access to the root apex, impeding optimal cleaning and shaping procedures. A case report is presented which uses a modern technique, utilising a staging platform and the use of newly designed ultrasonic tips with direct visualisation through a dental operating microscope, to remove a fractured rotary nickel-titanium instrument from the apical third of a curved root canal.

Adult↗

A comparison of digitally scanned radiographs with conventional film for the detection of small endodontic instruments.

The use of computers in dentistry is becoming common as a practice tool for a diverse number of tasks, including the storage and enhancement of intra-oral radiographs. Several systems of digital radiography are available to produce a digital image including irradiation of a charged-couple device and scanning conventional radiographs. This study compared various digital images of scanned periapical radiographs with the original radiographs to determine whether the digitized images offered any advantage when viewing small files at the radiographic apex. Twenty extracted permanent molar teeth were prepared by gaining straight line access to the root canals and a ISO size 06 K-file was introduced into one of the canals until the tip was flush with the apical foramen. Using a standardized technique, radiographs were taken of the teeth using E-speed film. The radiographs were scanned and five digital images: original, enhanced, negative to positive conversion, zoom and zoom of negative to positive were produced. Three evaluators compared each of the images with the radiograph for clarity of the endodontic file in relation to the radiographic apex. Results were analysed using the Wilcoxon signed rank test and the Kappa (kappa) test was used to measure the level of agreement between the three evaluators. The results revealed that all the digital images produced by this scanner were inferior to the radiograph (P < 0.001) and that there was high agreement between evaluators.

Dental Instruments↗

Study of calcium hydroxide apexification in 26 young permanent incisors.

This study was carried out in order to observe the effectiveness of apexification in young permanent incisors. The sample comprised 26 young permanent incisors with necrotic pulp and open apices. The time taken to obtain apical closure, its form and size were analysed in order to find out if closure was influenced by existing pathology or size of apex. The treated teeth were compared with their corresponding contralateral teeth. The test of McNemar and anova was used and a result of P = 0.05 was considered significant. Teeth with pretreatment apical shapes that were convergent or parallel all resulted in physiological apical shapes after treatment. Eight teeth had divergent apical shapes before treatment. Of these, one had a physiological shape, five ended with rounded apices and two teeth had straight apices post-treatment. Apical closure was obtained in 100% of the cases studied, of these 88.4% needed three to four sessions of calcium hydroxide treatment (an average of 3.23 sessions) in order to obtain apical closure, the average time employed was 12.19 months. Clinical symptoms resolved in all teeth that presented with symptoms. Preoperative symptoms did not affect outcome. Pathology of the tooth before treatment does not influence the time needed to obtain apical closure.

Analysis of Variance↗

Frequency of second mesiobuccal canals in maxillary molars as determined by use of an operating microscope: a clinical study.

Operating microscopes have recently been introduced to facilitate treatment of surgical and nonsurgical endodontic cases. The aim of this study was to determine in an in vivo clinical study if the use of an operating microscope would increase the number of second mesiobuccal canals located and obturated in maxillary first and second molars. Two hundred maxillary first and second molars treated with the aid of a microscope were evaluated. The number of second mesiobuccal canals that could be negotiated and obturated within 4 mm of the apex was recorded. Thirty percent of all maxillary molars had a negotiable second mesiobuccal canal. Evaluated separately, 33.1% of the maxillary first molars and 24.3% of the second molars had a negotiable second mesiobuccal canal. Results indicated that use of a surgical microscope did not increase the number of second mesiobuccal canals located, compared with those reports where access preparations were modified and the microscope was not used.

Dental Pulp Cavity↗

[Clinical study on the effect of Vitapex paste in apexification].

OBJECTIVE: The purpose of this article was to observe the effect of Vitapex Paste in apexilication. METHODS: 64 younger permanent teeth with underdeveloped apex and necrotic pulp were randomly selected. After root canals were prepared and sterilized, Vitapex paste was used in the apexification. All the teeth were observed for three years. RESULTS: 24 teeth (37.5%) were successful, 37 teeth (57.81%) were progressive, 3 teeth (4.69%) were failed. Altogether 61 teeth were effective, the effective rate was 95.31%. CONCLUSION: Vitapex paste was effective for the younger permanent teeth in the apexification.

Adolescent↗

Apical extrusion of debris and irrigants using two hand and three engine-driven instrumentation techniques.

AIM: To evaluate the weight of debris and irrigant volume extruded apically from extracted teeth in vitro after endodontic instrumentation using the balanced force technique, a hybrid hand instrumentation technique, and three engine-driven techniques utilizing nickel-titanium instruments (ProFile .04, Quantec 2000 and Pow-R). METHODOLOGY: Five groups of 20 extracted human teeth with single canals were instrumented using one or other of five techniques: balanced force, hybrid, Quantec 2000, ProFile .04, or Pow-R. Debris extruded from the apical foramen during instrumentation were collected into preweighed 1.5 mL tubes. Following instrumentation, the volume of extruded irrigant fluid was determined by visual comparison to control centrifuge tubes filled with 0.25 mL increments of distilled water. The weight of dry extruded dentine debris was also established. RESULTS: Overall, the engine-driven techniques extruded less debris than the manual ones. However, there was no statistical difference between the balanced force technique and the engine-driven methods. The volume of irrigant extruded through the apex was directly associated with the weight of extruded debris, except within the ProFile group. The hybrid technique was associated with the greatest extrusion of both debris and irrigant. CONCLUSIONS: Overall, the engine-driven nickel-titanium systems were associated with less apical extrusion.

Dental High-Speed Technique↗

Effect of different temperatures and penetration depths of a System B plugger in the filling of artificially created oval canals.

OBJECTIVES: The purpose of this study was to compare the gutta-percha-filled area in oval canals while varying the temperature and penetration depth of the System B plugger. STUDY DESIGN: Seventy-five resin blocks, with artificially created oval canals, were obturated by using a continuous wave technique. In groups 1, 2, and 3, the plugger was introduced to a depth of 4 mm from the apex at set temperatures of 100, 200, and 350 degrees C, respectively. In group 4, the plugger was inserted to a depth of 2 mm from the apex at a set temperature of 200 degrees C. Group 5 was obturated in the same way as group 2, and then an additional cold plugging was performed to a depth of 3 mm from the apex. The cross sections of the obturated canals were photographed, and the percentage of the gutta-percha-filled area (PGP) was measured. RESULTS: No significant differences were found between the 3 different temperature settings (P >.05). At 1 mm from the apex, group 4 showed the highest PGP (95.57% +/- 6.86), followed by group 5 (84.72% +/- 12.19), and group 2 (67.33 +/- 13.03) (P <.05). CONCLUSION: In artificially created oval canals, plugger temperature within the range used in this study did not affect the PGP. However, the penetration depth of the plugger was significantly related to PGP.

Acrylic Resins↗

The structure of dentine in the apical region of human teeth.

AIM: To study the structure of the apical region of human teeth with emphasis on dentinal tubules and their branches. METHODOLOGY: This descriptive histological study employed demineralized stained sections for light microscopy, demineralized unstained sections for scanning electron microscopy, and undemineralized, acid-etched specimens for confocal tandem scanning microscopy. RESULTS: The apical portion of human teeth showed marked variations in structure, including accessory root canals, areas of resorption and repaired resorptions, occasional attached, embedded and free pulp stones, varied amounts of irregular secondary dentine, and even cementum-like tissue lining the apical root canal wall. The apex often deviated from the long axis of the root canal. Primary dentinal tubules were irregular in direction and density. Some areas were devoid of tubules. CONCLUSIONS: The irregular and variable structure of the apical region of human teeth represent special challenges during endodontic therapy. Obturation techniques based on the penetration of adhesives into dentinal tubules are unlikely to be successful and adhesive techniques must depend on impregnation of a hybrid layer.

Adult↗

Apical pressures developed by needles for canal irrigation.

Drying instrumented canals with pressurized air may result in patient morbidity or even fatality. Low pressure and side vent needles have been suggested to lessen the danger. This study observed apical pressures from different needles inserted deeply into small round and ovoid canals as instrumentation progressed. Low-pressure (5 psi) air was injected through the needles, and apical pressures were recorded after each instrument. Pressures varied greatly within each test group. Generalities that can be drawn are that binding the needle within the canal gives higher pressures than with the needle slightly short of binding and that pressures were higher with apexes instrumented to size 30 and higher. With the needle tightly bound, neither needle size, needle design, nor canal shape resulted in statistically significant mean pressure differences. With the needle slightly withdrawn, larger bore needles gave higher pressures than small diameter needles. Caution is advised with the clinical use of pressurized air in the drying of root canals.

Air Pressure↗

Clinical and radiographic evaluation of root-canal obturation with obtura II.

This study evaluated clinical and radiographic healing of 236 root-canal treatments in 131 cases obturated with the Obtura II system. One operator performed all canal preparation and obturation with sealer. A standardized apical-coronal preparation technique instrumented all canals. Clinical symptoms, periodontal condition, and radiographic findings were evaluated at 3, 6, and 12 months. Radiographs taken immediately postobturation were compared to recall radiographs. The level of the final root filling was classified as short (more than 2 mm short of the apex), flush (within 2 mm), or over (beyond) in 12.7%, 81.4%, and 5.9% of cases, respectively. More than 96% of cases were treated successfully by the Obtura II system. Where roots were filled flush, over, or short, lesions healed in 97%, 93%, and 93% of cases, respectively, with no significant differences (p < 0.05). Root filling excess had no impact on the healing process.

Chi-Square Distribution↗

Vestibular surgical access to the palatine root of the superior first molar: "low-dose cone-beam" CT analysis of the pathway and its anatomic variations.

Apicoectomy of the superior first molar palatine root until recently involved relatively destructive and laborious surgery because of the palatal access route, which not only necessitates an extensive flap, but also the readying of procedures required to deal with a possible hemorrhage from the palatine artery. With the advent of operative microscopy, endodontic surgery has become more precise and less invasive and its technical potential has increased; a possible innovative surgical technique may entail vestibular root access. The possibility of using low-dose, low-cost computed tomography (CT) dedicated to the jaw to obtain anatomic information to plan apicoectomy via the vestibular approach was evaluated; 31 patients were referred to CT with the NewTom apparatus. In 43 superior first molars, the mean distance of the palatine root from the external vestibular cortex was measured, and the frequency that the maxillary sinus lateral recess lay between the roots was determined. The mean root apex-vestibular cortex distance was 9.73 mm. In 25% of cases the maxillary sinus recessus lay between vestibular and palatine roots. CT may play an important role in optimizing palatine root apicoectomy through vestibular access, with regard to precision and preventing complications, with relatively low biological and economic cost, also possibly contributing to the affirmation of this new surgical procedure.

Adolescent↗

The accuracy of three different electronic root canal measuring devices: an in vitro evaluation.

The main objective of this in vitro study was to evaluate the effects of the operator's experience level and pre-flaring on the accuracy of the results of three different brands of a new generation of root canal measuring devices, as well as the comparison among them. Extracted human teeth were prepared and then actual length and electronic length measurements were made by three different operators according to a double-blind technique. Three different operators performed electronic measurements on each specimen separately with three different electronic root canal measuring devices using in vitro models. Measurements were repeated by all operators after the pre-flaring. Taking the clinical tolerance of +/- 0.5 mm into account, there was no statistically significant difference between the accuracy of the instruments (P > 0.01). However, the results obtained from the Bingo electronic apex locator in pre-flared canals by the beginner operator were statistically significant (P < 0.01). All of the instruments had a clinically acceptable result at the tolerance of +/- 0.5 mm. If the instruments are used in accordance with the manufacturer's instructions, experience with electronic root canal measurement is not essential. However, the operator has to be more careful when working on pre-flared canals.

Analysis of Variance↗

Sealer distribution in root canals obturated by three techniques.

AIM: The aim of this study was to observe sealer distribution in root canals filled by different root filling techniques. METHODOLOGY: AH26 (0.05 mL) dyed with carbon black powder was placed into the prepared root canals of maxillary central incisors using a lentulo spiral. Thereafter the canals were obturated using three different gutta-percha root-filling techniques. Horizontal sections were cut in the apical and middle portions of the filled canals. Images of the cross sections were scanned and the percentage of sealer coated canal perimeter (PSCP) was measured using a computer digital imaging system. RESULTS: At 3 mm from the apex, the PSCP after lateral condensation was similar to that after vertical condensation (P > 0.05). At 6 mm from the apex, however, the PSCP was significantly higher after lateral condensation than after vertical condensation (P < 0.05). At both levels the PSCP was significantly higher after single cone (no condensation) than after the other two condensation techniques (P < 0.0001). CONCLUSIONS: Sealer may be removed from the canal wall by the condensation procedures.

Bismuth↗

A comparative study of apical leakage of Endomethasone, Top Seal, and Roeko Seal sealer cements.

A comparison was made of the apical leakage of three sealers. Fifty single-root human teeth were randomly divided into 5 groups (n = 10; 3 experimental and 2 control). The teeth of the positive-control and experimental groups were instrumented with K-type files to size 45. The experimental groups were obturated by laterally-vertically, condensed gutta-percha with Endomethasone, Top Seal, or RSA sealer cements. The positive-control group was nonobturated and the negative-control group was noninstrumented. The root surfaces were then coated with nail varnish (except the apex in the experimental groups) and immersed in black ink (for 1 week at 37 degrees C). The statistical evaluation of the results obtained by clearing and cross-section techniques showed no significant differences between sealers. Leakage, as determined by the clearing technique, was significantly greater than that quantified by cross-section analysis.

Administration, Topical↗