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Root Canal Walls (root + canal_wall)
Selected AbstractsSEM evaluation of root canal debridement with Sonicare CanalBrush irrigationINTERNATIONAL ENDODONTIC JOURNAL, Issue 5 2010M. I. Salman Salman MI, Baumann MA, Hellmich M, Roggendorf MJ, Termaat S. SEM evaluation of root canal debridement with Sonicare CanalBrush irrigation. International Endodontic Journal, 43, 363,369, 2010. Abstract Aim, To determine the efficacy of Sonicare CanalBrush irrigation for root canal cleaning. Methodology, Fifty human molar root canals were shaped with sequential NiTi rotary instruments up to size F3 (size 30, 0.09 taper; ProTaper system) and then enlarged apically with a Profile size 40, 0.04 taper. Five different irrigation protocols were tested (n = 10 canals per group) with 2 mL of distilled water (control, group I) or 2.5% NaOCl (control group II and test groups III, IV and V) between instrument size changes. Group III,IV received a final rinse with 17% EDTA for one min. This was extended by 30 s in group IV, whereas group V received this additional 30 s of 17% EDTA sonically dispersed with a Sonicare CanalBrush. For cleanliness evaluations, roots were split longitudinally, examined with scanning electron microscopy and scored according to Hülsmann et al. (1997) for debris and smear layer on the surface of the root canal wall. Walls were assessed at the coronal, middle and apical thirds. Data were analysed with the Kruskal,Wallis and Mann,Whitney tests. Results, Irrigation with 17% EDTA significantly reduced debris and smear layer scores (P < 0.05) compared to controls. The coronal and middle thirds had lower debris and smear layer scores than the apical third (P < 0.05). In all thirds, sonic agitation of the irrigant with a CanalBrush (group V) resulted in significantly cleaner canal walls compared to all other groups (P < 0.05). Conclusions, Irrigation by agitation with the Sonicare CanalBrush improved root canal debridement in the coronal, middle and particularly the apical thirds of the root canal. [source] Efficacy of three rotary NiTi instruments in removing gutta-percha from root canalsINTERNATIONAL ENDODONTIC JOURNAL, Issue 3 2008T. Ta, demir Abstract Aim, To investigate the ability of three rotary nickel,titanium instruments and hand instrumentation to remove gutta-percha and sealer. Methodology, Sixty freshly extracted human single-rooted teeth, each with one root canal, were instrumented with K-files and filled using cold lateral compaction of gutta-percha and AH Plus (Dentsply Detrey, Konstanz, Germany) sealer. The teeth were randomly divided into four groups of 15 specimens each. Removal of gutta-percha was performed with the following devices and techniques: ProTaper, R-Endo, Mtwo and Hedström files. The specimens were rendered transparent and the area of remaining filling material on the root canal wall was measured using a computer image analysis program. Statistical analysis was accomplished by Kruskal,Wallis and Mann,Whitney U -tests with Bonferroni correction for the analysis of residual root filling material and working time. Results, The ProTaper group had less filling material inside the root canals than the other groups, but a significant difference was found between only the ProTaper and Mtwo groups (P < 0.05). The retreatment time for Mtwo and ProTaper was significantly shorter compared with R-Endo and manual instrumentation with Hedström files (P < 0.001). R-Endo was significantly faster than manual instrumentation (P < 0.001). Conclusions, Under the experimental conditions, ProTaper left significantly less gutta-percha and sealer than Mtwo instruments. Complete removal of materials did not occur with any of the instrument systems investigated. [source] The structure of dentine in the apical region of human teethINTERNATIONAL ENDODONTIC JOURNAL, Issue 5 2001I. A. Mjör Abstract 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. [source] Effect of access cavity location and design on degree and distribution of instrumented root canal surface in maxillary anterior teethINTERNATIONAL ENDODONTIC JOURNAL, Issue 3 2001G. Mannan Abstract Aim The null hypothesis tested in this study was that in single-rooted anterior teeth with simple root canal anatomy, different access cavity designs (,lingual cingulum', ,lingual conventional', ,incisal straight-line') do not influence the ability of endodontic files to plane the walls of the root canals. Methodology, Thirty extracted human maxillary anterior teeth were divided randomly into three groups for each access cavity. The access cavities were prepared according to predefined criteria and the roots embedded in individual polyvinyl-siloxane putty matrices. The matrices allowed these teeth to be split into buccal and palatal halves and to be reassembled. The split teeth enabled removal of pulpal remnants from the root canal system and the walls to be stained with an even layer of permanent black ink. Once dried, the split roots were reassembled in the putty matrices and a step-back filing technique was used to prepare the canals with water irrigation. The canal walls were examined for residual ink staining and scored by three independent assessors using an index devised for the purpose. Results There was good agreement between the assessors. None of the access cavities allowed file contact with the entire root canal wall. The overall (palatal and buccal sections) scores showed significant differences (P < 0.01) between the access cavity groups in the extent to which the canal walls could be filed. The straight-line incisal access cavity had the greatest proportion of instrumented root canal surface. The lingual cingulum access cavity was the worst in this respect. The differences in residual ink scores between the access cavity types were significant for the buccal halves (P < 0.01) but not for the palatal halves (P > 0.05). Conclusions The null hypothesis was proven. Regardless of access cavity design, mechanical preparation did not allow instrumentation of the entire root canal wall. Straight-line access allowed the greatest proportion of the root canal wall to be instrumented and the lingual cingulum access the least. [source] Comparative in vitro study of the sealing efficiency of white vs grey ProRoot mineral trioxide aggregate formulas as apical barriersDENTAL TRAUMATOLOGY, Issue 2 2008Spyridon Stefopoulos Recently conventional grey MTA has been replaced by a new white MTA formula. The aim of this study was to compare the root canal adaptation of white MTA to that of grey MTA when used as an apical barrier in teeth with open apices. We also examined whether a previous calcium hydroxide intracanal medication affects MTA's sealing ability and investigated the ability to remove calcium hydroxide from the root canal walls. Forty-nine teeth were prepared in a manner to simulate a divergent open apex of immature teeth. Four teeth were used in a preliminary experiment to demonstrate the inefficacy of calcium hydroxide removal from the canal walls in teeth with open apices. Four groups of 10 teeth each were created: groups A and B were treated with calcium hydroxide intracanal medication and then received an apical plug of grey and white MTA respectively. Groups C and D received an apical plug of grey and white MTA respectively without previous intracanal medication. Four teeth served as negative and one as a positive control. The marginal adaptation and sealing ability of the apical barrier were tested by means of a dye tracer (basic fuchsine) after longitudinal sectioning. It was found that MTA apical barrier resisted displacement during gutta-percha condensation. Calcium hydroxide pretreatment, adversely affected white MTA sealing ability (P < 0.05). [source] The effect of mineral trioxide aggregate on the apexification and periapical healing of teeth with incomplete root formationINTERNATIONAL ENDODONTIC JOURNAL, Issue 1 2006W. T. Felippe Abstract Aim, To evaluate the influence of mineral trioxide aggregate (MTA) on apexification and periapical healing of teeth in dogs with incomplete root formation and previously contaminated canals and to verify the necessity of employing calcium hydroxide paste before using MTA. Methodology, Twenty premolars from two 6-month old dogs were used. After access to the root canals and complete removal of the pulp, the canal systems remained exposed to the oral environment for 2 weeks. Canal preparation was then carried out using Hedström files, under irrigation with 1% sodium hypochlorite, 1 mm short of the radiographic apex. After drying, the canals of two premolars in each dog were left empty (control group). The other eight teeth in each animal were divided into two experimental groups. The apical thirds of the canals of group 1 were filled with MTA. In the teeth of group 2, the canals were dressed with a calcium hydroxide,propylene glycol paste. After 1 week, the paste was removed and the apical third was filled with MTA. All teeth were restored with reinforced zinc oxide cement (IRM) and amalgam. The animals were killed 5 months later, and blocks of the teeth and surrounding tissues were submitted to histological processing. The sections were studied to evaluate seven parameters: formation of an apical calcified tissue barrier, level of barrier formation, inflammatory reaction, bone and root resorption, MTA extrusion, and microorganisms. Results of experimental groups were analysed by Wilcoxon's nonparametric tests and by the test of proportions. The critical value of statistical significance was 5%. Results, Significant differences (P < 0.05) were found in relation to the position of barrier formation and MTA extrusion. The barrier was formed in the interior of the canal in 69.2% of roots from MTA group only. In group 2, it was formed beyond the limits of the canal walls in 75% of the roots. MTA extrusion occurred mainly in roots from group 2. There was similarity between the groups for the other parameters. Conclusions, Mineral trioxide aggregate used after root canal preparation favoured the occurrence of the apexification and periapical healing. The initial use of calcium hydroxide paste was not necessary for apexification to occur, and has shown to be strongly related to the extrusion of MTA and formation of barriers beyond the limits of the root canal walls. [source] Effectiveness in cleaning oval-shaped root canals using Anatomic Endodontic Technology, ProFile and manual instrumentation: a scanning electron microscopic studyINTERNATIONAL ENDODONTIC JOURNAL, Issue 6 2005O. Zmener Abstract Aim, To compare in vitro the cleanliness of root canal walls in oval-shaped root canals following automated or manual instrumentation. Methodology, Forty-five oval-shaped single-rooted maxillary and mandibular premolars with straight canals were divided into three groups of 15. Automated canal preparation was performed using Anatomic Endodontic Technology (AET, group 1) and the ProFile system (group 2). Manual instrumentation (group 3) was performed with K-Flexofiles. Irrigation was performed using alternately 5.25% NaOCl and 17% EDTA, followed by rinsing with saline. The roots were split longitudinally into halves and the canals examined at ×200 and ×400 in a scanning electron microscope. The presence of debris and smear layer was recorded at distances of 1, 5 and 10 mm from the working length using a three-step scoring scale and a 300 ,m square grid. Mean scores for debris and smear layer were calculated and statistically analysed for significance (P < 0.05) between and within groups, using the Kruskal,Wallis nonparametric anova and Dunn's tests. Results, At 1, 5 and 10-mm levels the root canals prepared with AET had significantly less surface debris and smear layer on the canal walls compared with canals prepared with ProFile or manual instrumentation. For all three groups significantly lower mean smear layer scores (P < 0.05) were recorded at 5 and 10-mm levels compared with the 1 mm level. Significantly lower mean debris scores (P < 0.05) were also recorded at 5 and 10-mm levels for the AET group whereas no significant differences were found between the three levels for the ProFile and manual instrumentation groups. Conclusions, Although better instrumentation scores were obtained in canals prepared with AET, complete cleanliness was not achieved by any of the techniques and instruments investigated. [source] Effectiveness of different techniques for removing gutta-percha during retreatmentINTERNATIONAL ENDODONTIC JOURNAL, Issue 1 2005A. V. Masiero Abstract Aim, To evaluate the effectiveness of various techniques for removing filling material from root canals in vitro. Methodology, Eighty extracted mandibular premolar teeth were selected for the study. The teeth were root filled using thermomechanical compaction of gutta-percha. After 8 months, the filling material was removed and canals were reinstrumented using the following techniques: group I , hand instrumentation with K-type files (SybronEndo, Orange, CA, USA); group II , K3 Endo System (SybronEndo); group III , M4 system (SybronEndo) with K-type files (SybronEndo); and group IV , Endo-gripper system (Moyco Union Broach, York, PA, USA) with K-type files (SybronEndo). The amount of filling debris remaining on root canal walls was assessed radiographically; the images were digitized and analysed using AutoCAD 2000 software. Total canal area, area of the cervical, middle and apical thirds, and area of remaining filling material were outlined by one operator. The ratios between these areas were calculated as percentages of remaining debris. Thereafter, data were analysed by means of one-way anova and the post-hoc Duncan test to identify differences between the four techniques. Results, Multiple comparisons of the percentages of remaining filling material in the entire canal did not reveal any significant differences between the methods of removal. However, when each third was analysed separately, significant differences for remaining debris were present between groups. The apical third had the most remaining material, whilst the cervical and middle thirds were significantly cleaner (P = 0.002). Comparison of the techniques revealed that teeth instrumented with K3 rotary instruments had a lower ratio of remaining filling material in the apical third (P = 0.012). Conclusion, In the apical third, K3 rotary instruments were more efficient in removing gutta-percha filling material than the other techniques, which were equally effective for the other thirds. [source] Comparison of root canal preparation using RaCe and ProTaper rotary Ni-Ti instrumentsINTERNATIONAL ENDODONTIC JOURNAL, Issue 1 2005F. Paqué Abstract Aim, To compare various parameters of root canal preparation using RaCe (FKG Dentaire, La-Chaux-de-Fonds, Switzerland) and ProTaper (Dentsply Maillefer, Ballaigues, Switzerland) nickel-titanium (Ni-Ti) instruments. Methodology, Fifty extracted mandibular molars with mesial root canal curvatures between 20° and 40° were embedded in a muffle system. All root canals were prepared to size 30 using RaCe or ProTaper rotary instruments in low-torque motors with torque control and constant speed of 300 r.p.m. (ProTaper with ATR Tecnika, Advanced Technology Research, Pistoia, Italy; RaCe with EndoStepper, S.E.T., Olching, Germany). In both groups irrigation was performed with 2 mL NaOCl (3%) after each instrument size. Calcinase-Slide (lege artis, Dettenhausen, Germany) was used as a chelating agent with each instrument. The following parameters were evaluated: straightening of curved root canals, postoperative root canal cross-sections, safety issues and working time. Cleanliness of the root canal walls was investigated under the SEM using 5-score indices for debris and smear layer. Statistical analysis was performed using the following tests: Wilcoxon's test for straightening and working time was used (P < 0.05); Fisher's exact test for comparison of cross-sections and root canal cleanliness (P < 0.05). Results, Both Ni-Ti systems maintained curvature well; the mean degree of straightening was less than 1° for both systems. Following preparation with RaCe, 49% of the root canals had a round or oval diameter and 50% an irregular diameter, ProTaper preparations resulted in a round or oval diameter in 50% of the cases. For debris, RaCe and ProTaper achieved 47 and 49% scores of 1 and 2, respectively; there was no significant difference. For smear layer, RaCe and ProTaper achieved 51 and 33% scores 1 and 2, respectively; no statistically significant differences were apparent for the coronal and middle sections of the root canals, but RaCe performed significantly better in the apical region (Fisher's exact test, P = 0.0392). Two roots lost working length with RaCe instruments, whilst ProTaper preparation resulted in two roots loosing working length and one fractured instrument. Mean working time was shorter for ProTaper (90.9 s) than for RaCe (137.6 s); the difference was significant (Wilcoxon's test, P = 0.011). Conclusions, Both systems respected original root canal curvature well and were safe to use. Cleanliness was not satisfactory for both systems. [source] The effectiveness of syringe irrigation and ultrasonics to remove debris from simulated irregularities within prepared root canal wallsINTERNATIONAL ENDODONTIC JOURNAL, Issue 10 2004S.-J. Lee Abstract Aim, To compare the ability of syringe irrigation and ultrasonic irrigation to remove artificially placed dentine debris from simulated canal irregularities within prepared root canals. Methodology, After canal enlargement, twelve canines were split longitudinally into two halves. On the wall of one half of each root canal a standard groove of 4 mm in length, 0.2 mm in width and 0.5 mm in depth was cut, 2,6 mm from the apex, to simulate uninstrumented canal extensions. On the wall of the other half, three standard saucer-shaped depressions of 0.3 mm in diameter and 0.5 mm in depth were cut at 2, 4 and 6 mm from the apex to simulate uninstrumented canal irregularities. Each groove and depression were filled with dentine debris mixed with 2% NaOCl to simulate a situation when dentine debris accumulates in uninstrumented canal extensions and irregularities during canal preparation. Each tooth was re-assembled by reconnecting the two halves, using wire and an impression putty material. Two per cent NaOCl was then delivered into each canal either using syringe irrigation (n = 8) or using ultrasonic irrigation (n = 8). Before and after irrigation, images of the two halves of the canal wall were taken, using a microscope and a digital camera, after which they were scanned into a PC as TIFF images. The amount of remaining dentine debris in the grooves and depressions was evaluated by using a scoring system between 0,3: the higher the score, the more the debris. The data were analysed by means of the Mann,Whitney U -test. Results, Both forms of irrigation reduced the debris score significantly. The debris score was statistically significantly lower after ultrasonic irrigation than after syringe irrigation (P = 0.002 for grooves, P = 0.047 for depressions). Conclusion, Ultrasonic irrigation ex vivo is more effective than syringe irrigation in removing artificially created dentine debris placed in simulated uninstrumented extensions and irregularities in straight, wide root canals. [source] Evaluation of smear layer removal by EDTAC and sodium hypochlorite with ultrasonic agitationINTERNATIONAL ENDODONTIC JOURNAL, Issue 5 2002D. M. Z. Guerisoli Abstract Aim To evaluate smear layer removal by different irrigating solutions under ultrasonic agitation. Methodology Twenty recently extracted mandibular incisors with a single root canal were divided into four equal groups. Three groups were instrumented using the modified double-flared technique, the fourth remained unprepared. Each group was irrigated with either distilled water, 1.0% sodium hypochlorite alone or associated with 15% EDTAC between each file size. The final group was not instrumented but irrigated with 1.0% sodium hypochlorite and 15% EDTAC. A size 15 file energised by ultrasound was used with small amplitude filing movements against the canal walls in all groups. The teeth were split longitudinally and the roots measured to provide three sections of the same size (cervical, middle and apical). Samples were examined under the scanning electron microscope and assessed for the amount of smear layer by three independent and calibrated examiners. The scoring system ranged from 1 (no smear layer) to 4 (all areas covered by smear layer). Due to the non-parametric nature of the data, Friedman's test was used for statistical analysis. Results Canal walls were covered with smear layer in the group irrigated with 1% sodium hypochlorite alone and the group irrigated with distilled water. Canals irrigated with 1.0% sodium hypochlorite associated with 15% EDTAC had less smear layer throughout the canal (P < 0.001). There were no statistical differences for the amount of smear layer found on the cervical, middle and apical thirds when each group was analysed separately. Conclusions Under ultrasonic agitation, sodium hypochlorite associated with EDTAC removed the smear layer from root canal walls, whereas irrigation with distilled water or 1.0% sodium hypochlorite alone did not remove smear layer. [source] A scanning electron microscopic study of debris and smear layer remaining following use of GT rotary instrumentsINTERNATIONAL ENDODONTIC JOURNAL, Issue 5 2002G. Gambarini Abstract Aim The aim of the present study was to assess debris and smear layer remaining following canal preparation with GT rotary instruments. Methodology Sixteen freshly extracted single-rooted premolar teeth were instrumented with GTÔ rotary instruments using a crown-down preparation technique. All specimens were flushed with 2 mL of 5% NaOCl between each rotary instrument. At the end of instrumentation the following final irrigation sequence was repeated two times: 2 mL of EDTA + Cetrimide for 1 min (Largal Ultra, Septodont, France) and 2 mL of 5% NaOCl for 5 min. A final flush with saline solution was made to halt any chemical activity. Two other uninstrumented teeth that were not irrigated served as controls. All teeth were split longitudinally and prepared for SEM evaluation. The presence of debris and smear layer was evaluated from photomicrographs at ×200 and ×1000 magnification taken in the apical, middle and coronal thirds of the canals. Blind evaluation was performed by two trained observers and scores were compiled separately. A five category scoring system for debris and smear layer was used. Values obtained were tabulated and statistical analysis was carried out using a parametric chi-squared test. Results Statistical analysis showed that there was no significant difference between the three regions of the root canals (P > 0.05) for debris. Comparison of the removal of the smear layer between the three regions showed that there was a statistically significant difference between all parts, especially between the coronal and apical thirds (P < 0.001). Overall, the coronal sections were cleaner than the middle and apical sections. The uninstrumented canals showed walls completely covered with tissue, confirming that specimen preparation alone did not remove tissue. Conclusions Under the conditions of the present study GTÔ rotary instruments removed debris effectively, but left root canal walls covered with smear layer, particularly in the apical third. [source] Cleaning effectiveness of root canal irrigation with electrochemically activated anolyte and catholyte solutions: a pilot studyINTERNATIONAL ENDODONTIC JOURNAL, Issue 6 2000A. M. Solovyeva Abstract Aim The aim of this study was to evaluate the potential of electrochemically activated (ECA) anolyte and catholyte solutions to clean root canals during conventional root canal preparation. Methodology Twenty extracted single-rooted human mature permanent teeth were allocated randomly into four groups of five teeth. The pulp chambers were accessed and the canals prepared by hand with conventional stainless steel endodontic instruments using a double-flared technique. One or other of the following irrigants was used during preparation: distilled water, 3% NaOCl, anolyte neutral cathodic (ANC) (300 mg L,1 of active chlorine), and a combination of anolyte neutral cathodic (ANC) (300 mg L,1 of active chlorine) and catholyte. The teeth were split longitudinally and the canal walls examined for debris and smear layer by scanning electron microscopy. SEM photomicrographs were taken separately in the coronal, middle and apical parts of canal at magnification of ×800 to evaluate the debridement of extra-cellular matrix and at a magnification of ×2500 to evaluate the presence of smear layer. Results Irrigation with distilled water did not remove debris in the apical part of canals and left a continuous and firm smear layer overlying compressed low-mineralized predentine. All chemically active irrigants demonstrated improved cleaning potential compared to distilled water. The quality of loose debris elimination was similar for NaOCl and the anolyte ANC solution. The combination of anolyte ANC and catholyte resulted in improved cleaning, particularly in the apical third of canals. The evaluation of smear layer demonstrated that none of the irrigants were effective in its total removal; however, chemically active irrigants affected its surface and thickness. Compared to NaOCl, the ECA solutions left a thinner smear layer with a smoother and more even surface. NaOCl enhanced the opening of tubules predominantly in the coronal and middle thirds of canals, whereas combination of ANC and catholyte resulted in more numerous open dentine tubules throughout the whole length of canals. Conclusions Irrigation with electrochemically activated solutions cleaned root canal walls and may be an alternative to NaOCl in conventional root canal treatment. Further investigation of ECA solutions for root canal irrigation is warranted. [source] | ||||||||||