Influence of Hero Apical instruments on cleaning ovoid-shaped root canals

Abstract

The cleaning capacity of Hero 642 nickel-titanium files, complemented by the Hero Apical instruments in flattened roots, was determined by histological analysis, considering the area of action of the instruments on the coronal walls and the presence of remaining debris. Twenty-four single-canal, human mandibular incisors were divided into three groups and prepared as follows: GI, instrumented with Hero 642 NiTi files 30/.06, 25/.06, 20/.06, 25/.06, and 30/.06; GII, instrumented as GI followed by Hero Apical size 30/.06; GIII, instrumented as GI followed by Hero Apical sizes 30/.06 and 30/.08, then returning to 30/.06 with pendulum movements. The apical thirds were prepared for histological processing, analyzed at 40× magnification and the images were examined morphometrically. Statistical analysis showed that GIII presented the best results for removing debris (5.22% ± 4.13), with more contact between the instruments and the root canal walls (19.31% ± 0.15). This differed statistically from GI (14.04% ± 4.96 debris removal, with 42.96% ± 7.11 instrument contact) and GII (12.62% ± 5.76 debris removal, with 35.01% ± 0.15 instrument contact). Root canal preparation with Hero 642, complemented by Hero Apical instruments (30/.06 and 30/.08, then re-instrumented with Hero Apical 30/.06 using pendulum movements), was more efficient for debris removal and allowed more contact of the instruments with the root canal walls. GII presented the worst results.

Análise Da Capacidade De Limpeza De Três Técnicas De Instrumentação Em Canais Radiculares Achatados: Diaphanization Study

“…(19,(28)(29)(30) According to the present study, more than 76.4% of the walls that remained dirty after preparation were buccal or lingual walls, demonstrating the challenge of the instrumentation of these areas in flattened canals.…”

“…(13)(14)(15)(16) Flattened or oval canals studies use the mesial root of molars (17,18) or mandibular incisors. (5,10,19,20) Extracted mandibular incisors were used in this study by having a pronounced flattening on the mesiodistal direction, which can generate a second canal lingually located to the main one, as well as the occurrence of severely flattened canals, with elongated cross-section, being the biggest diameter on the buco-lingual direction. (13) Mandibular incisors with more than one root canal were excluded and only the ones with mesiodistal flattening were used.…”

Assessing apical transportation in curved canals: comparison between cross-sections and micro-computed tomography

“…[5][6][7][8][9][10] The limitations of each of these methods have been extensively discussed, 11,[20][21][22][23] encouraging continuing research into technologies that allow both quantitative and qualitative three-dimensional assessments of the root canal. To this end, the present study compared the µCT and the cross-sectioning methods used to quantify apical transportation after rotary instrumentation of curved canals at 2.0, 3.5, and 5.0 mm from the apex.…”

“…3,4 In addition to the advances made in rotary instrumentation, different methodologies have been proposed and used to assess the effects of endodontic instruments on canal transportation and on root canal anatomy. [5][6][7][8][9] Physical crosssectioning is one of the experimental models currently available to evaluate changes in root canal anatomy before and after instrumentation. 10 However, Declaration of Interests: The authors certify that they have no commercial or associative interest that represents a conflict of interest in connection with the manuscript.…”

Influence of Prior Cervical Enlargement on Apical Cleaning Using Single File

“…Currently, this is not possible, however, as no available preparation technique will allow the root canal to be completely cleaned, particularly in the anatomical region of the apical third. This means that the clinical success of the endodontic treatment may be undermined 10,12) . Several types of endodontic rotary instrument have been developed with a view to optimizing such treatment, which has led to the gradual replacement of manual with mechanical instruments 10,17,22) .…”