Lateral Compaction Of Gutta-percha Research Articles

Improvement of the Endodontic Treatment Efficiency of the Maxillary First Molars Using Differentiated Instrumental Preparation of the Apical Part and Additional Sealing of Root Canal Orifices

Introduction. Endodontic treatment of maxillary first molars (MFMs) is very challenging due to the anatomical complexity of root canals which makes it difficult to do the proper cleaning, shaping, and obturation.
 Aim was to study the effectiveness of a proposed endodontic treatment of maxillary first molars, compared to the traditional method, in patients with and without concomitant generalized periodontitis.
 Methods. Endodontic treatment of 176 maxillary first molars was carried out according to the traditional method and proposed one, which included a differentiated approach to the instrumental preparation of the apical part of the root canal, and additional sealing of the root canals orifices using glass-ionomer cement. Obturation was conducted by lateral compaction of gutta-percha, combined with zinc-oxide-eugenol (ZOE) sealer and sealer based on epoxy resins. The effectiveness of endodontic treatment was evaluated based on the radiological comparison of the index, area of periapical destruction, and optical density of treated teeth roots immediately after, in 6 and 12 months.
 Results. In 12 months after the endodontic treatment in the subgroups where the proposed technique was used, in patients with chronic apical periodontitis, better positive dynamics of the % increase in densitometric indicators, % increase of ​​periapical bone destruction, and the decrease of PAI were noted. The % increase of the ​​destruction area in the subgroup with the proposed treatment in combination with ZOE sealer was (79.21±2.41) %, that characterizes the decrease in the area from 14.03±0.7 mm2 to 2.65±0.26 mm2. It was established that the index of endodontic treatment effectiveness is significantly lower in patients with generalized periodontitis of 2nd degree, compared to patients with healthy periodontium(p<0.05).
 Conclusions. It was established that the combination of the proposed method of treatment and ZOE sealer showed high effectiveness of endodontic treatment, due to the radiological picture in 12 months. It was found that there can be a possible negative effect of tooth mobility on the prognosis of endodontic treatment.

The impact of two root canal treatment protocols on the oral health-related quality of life: a randomized controlled pragmatic clinical trial.

To assess the impact of two root canal treatment protocols on the oral health-related quality of life (OHRQoL) of patients in need of root canal treatment on their anterior teeth. The sample consisted of 120 participants (mean age: 34years) enrolled in a pragmatic randomized clinical trial evaluating two root canal treatment protocols. Anterior teeth with nonvital pulps were allocated for root canal preparation with either hand files and filled with lateral compaction of gutta-percha (manual protocol) or canal preparation with a single file in a reciprocating movement and filled with a single cone technique (Reciproc protocol). OHRQoL data were assessed using the Oral Health Impact Profile instrument (OHIP-14), which was administered before the root canal intervention (baseline), and 6 and 12months after treatment. Demographic and clinical characteristics of participants were collected at baseline. Data were analysed using bivariate analyses, Poisson univariate and multiple regression (α=0.05). The drop-out rate from baseline was 27% and 28% at 6 and 12months after treatment, respectively. Both root canal protocols significantly enhanced patients' OHRQoL, regardless of the follow-up time (P<0.001). After 6months, patients treated with the Reciproc protocol had significantly lower OHIP-14 overall scores (P=0.030), as well as significantly lower scores for psychological discomfort (P=0.031) and social disability (P=0.013). After 12months, no significant difference was observed between the two root canal protocols for OHIP-14 overall scores (P=0.174). Either large or moderate effect sizes were observed for all domains and overall scores at both evaluation times, irrespective of the protocol. Low-income persons (RR=2.03) and the Reciproc protocol (RR=1.52) had a higher likelihood of a positive impact on OHRQoL 12months after root canal treatment. The two root canal protocols improved the OHRQoL and differences in scores were observed only after 6months with poorer OHRQoL for the manual protocol. After 12months, patients with low-income status and treated with Reciproc were associated with a greater improvement in OHRQoL scores.

CLINICAL EFFECTIVENESS OF TREATMENT THE PATIENTS WITH CHRONIC APICAL PERIODONTITIS

Background. The success of endodontic treatment is provided by a thorough instrumental and antiseptic treatment of infected root canals, and it depends on the composition of filling material, the degree of adhesion to dentin, hermetic obturation of apical foramen, solubility of sealer.Objective. The study was aimed to evaluate the effectiveness of root canal obturation with BioRootTM RCS sealer in the treatment of patients with chronic apical periodontitis.Materials and methods. Endodontic treatment of 23 teeth in 20 patients with chronic apical periodontitis by method of lateral compaction of gutta-percha was carried out. In the main group root canals were obturated with BioRootTM RCS, in the control group the canals were filled with Apexit Plus. The percentage of efficient or non-efficient cases was evaluated on the basis of radiographic comparison of treated chronic apical periodontitis immediately after obturation, in three, six months and one year. Radiographic conditions were defined as existing state, improvement and worsening.Results. In a year of dynamic evaluation the final results were: in the main group – 54.55% of the patients had complete bone healing, in 27.27% of cases the focus of bone destruction was decreased by ½ or more of the initial sizes, 18.18% – resorption lesion was decreased by less than ½; in the control group – 33.33% of improvement, 25.0% of existing state and 41.66% of worsening.Conclusions. BioRootTM RCS using for root canals obturation in the treatment of chronic apical periodontitis we proved the high effectiveness of the treatment undertaken: complete healing or improvement of radiographic conditions of periapical bone destruction with X-ray signs of bone regeneration.

Apical Microleakage in Root Canals Containing Broken Rotary Instruments.

Introduction:Broken instruments in root canals complicate routine endodontic treatment. This study aimed to compare apical microleakage in root canals containing broken rotary instruments filled with mineral trioxide aggregate (MTA), calcium-enriched mixture (CEM) cement, laterally compacted gutta-percha and injected gutta-percha. Methods and Materials:In this in vitro, experimental study, 80 extracted human premolars were decoronated and then the roots were randomly divided into four groups (n=20). Root canals were instrumented with Mtwo rotary files. The files were scratched 3 mm from the tip by a high speed handpiece and they were intentionally broken in the apical third of the canals. The middle and coronal thirds of the canals were then filled with MTA, CEM cement, gutta-percha with lateral compaction technique and injected gutta-percha. Apical microleakage was measured using dye penetration method. Data were analyzed using ANOVA and Tukey’s test.Results:Root canals filled with CEM cement showed the lowest and those filled with injected gutta-percha showed the highest microleakage according to dye penetration depth. No significant difference was noted between the microleakage of CEM cement and MTA or between lateral compaction of gutta-percha and injected gutta-percha (P>0.05). However, CEM cement and MTA groups had significantly lower microleakage than laterally compacted and injected gutta-percha groups (P<0.05). Conclusion:Due to their superior sealing ability, MTA and CEM cement are suitable for filling of root canals containing a broken instrument compared to laterally compacted and injected gutta-percha.

Efficacy Of Two NI-TI Retreatment Systems and Hand Files in Removing Gutta-Percha and Sealer From Root Canals Filled With Three Different Types of Sealers

Abstract Objectives: This study was undertaken to evaluate the efficiency of two rotary nickel titanium instruments and hand instrumentation in removing gutta-percha and sealer from root canals. Study design: – 63 extracted human single rooted premolars were instrumented with K-files and filled using lateral compaction of gutta-percha (GP) and three different sealers. The teeth were randomly divided into three experimental groups of 21 specimens each. Removal of gutta-percha was performed with R-Endo retreatment files, Mtwo retreatment files and Hedstrom files. Time to reach working length and to eliminate filling material was also recorded. The specimens were sectioned for evaluation of the area of the remaining gutta-percha/sealer under stereomicroscope at 6X magnification. Photographs were taken for further analysis using computer image analysis program. The results were statistically analyzed using Analysis of variance (ANOVA) and Tukey’s honestly significant difference test. Results: The R-Endo retreatment system resulted in a smaller percentage of canal area covered by residual GP/sealer than in other groups, a significant difference was found between R-Endo and Mtwo group and between Hedstrom groups (P &lt; 0.001). The Mean operating time was minimum with R-Endo group while it was found to be maximum with hand files. Conclusion: It was concluded that all test techniques left gutta-percha/sealer remnants within the root canal. The R-Endo retreatment files and Mtwo retreatment files system proved to be an efficient method for removing gutta-percha and sealer from single rooted premolars.

Porosity distribution in root canals filled with gutta percha and calcium silicate cement

ObjectiveGutta percha is commonly used in conjunction with a sealer to produce a fluid-tight seal within the root canal fillings. One of the most commonly used filling methods is lateral compaction of gutta percha coupled with a sealer such as calcium silicate cement. However, this technique may result in voids and worse, the filling procedures may damage the root. MethodsWe compared the volume of the voids associated with two root canal filling methods, namely lateral compaction and single cone. Micro-computed tomography was used to assess the porosity associated with each method in vitro. An automated, observer-independent analysis protocol was used to quantify the unfilled regions and the porosity located in the sealer surrounding the gutta percha. ResultsSignificantly less porosity was observed in root canals filled with the single cone technique (0.445% versus 3.095%, p<0.001). Porosity near the crown of the tooth was reduced 6 fold, whereas in the mid root region porosity was reduced to less than 10% of values found in the lateral compaction filled teeth. SignificanceOur findings suggest that changing the method used to place the endodontic biomaterials improves the quality and homogeneity of root canal fillings.

Effectiveness of hand versus rotary instrumentation on retreatment of curved canals

Background: Various nickel–titanium (NiTi) rotary endodontic instruments have been developed to facilitate cleaning and shaping of root canals. This study aimed to evaluate the efficiency, cleaning ability and safety of two different rotary NiTi instruments with a solvent versus hand files in the removal of canal fillings. Methods: Forty five simulated canals with 35° curves made of clear polyester resin were used in this study. All canals were prepared with K-files and filled using cold lateral compaction of gutta-percha and AH Plus sealer. The teeth were randomly divided into three groups of 15 specimens each. Removal of gutta-percha was performed with the following techniques: Hedstrom files, ProTaper Universal rotary retreatment system and Mtwo-R. All techniques were used with the solvent chloroform. The followings factors were evaluated: time taken to reach working length, time for gutta-percha removal, total time, apically extruded material during filling removal and number of fractured instruments. Pre- and post-reinstrumentation weights of all the blocks were recorded and efficacy capacity of each retreatment technique was assessed. Results: The canal wall clearance efficiency of ProTaper retreatment files were more successful than Mtwo-R and hand instruments. With respect to the difference between pre- and post-reinstrumentation weights, Mtwo-R was the most effective instrumentation technique. Regarding the mean time of retreatment and time required for reaching the working length, Mtwo-R instruments were significantly faster than the others. In addition, the hand instrumentation was more successful comparing to others in terms of the amount of apically extruded material. Conclusion: Under experimental conditions, Mtwo-R/Mtwo and ProTaper retreatment instruments proved to be efficient and time-saving devices for the removal of gutta-percha .

Solvency Capacity of Gutta Percha Using Chloroform and Eucalyptol: A Scanning Electron Microscopic Study

Aim: To evaluate the solvency of chloroform and eucalyptol for gutta percha removal in re-treatment. Methodology- A total of 40 extracted human maxillary single rooted teeth were selected. Canal preparation was carried out by the sequential use of K- files up to size 30 at working length and then divided into one control group(n=10)that is group I and three experimental groups II,III,IV (n=10 each).The experimental groups were obturated by lateral compaction of gutta percha using zinc oxide eugenol sealer. During retreatment chloroform and eucalyptol severed as solvent in all groups. In group II no solvent ,group III chloroform and group IV eucalyptol, were used for gutta percha removal. Scanning electron microscopy was done to check the efficacy and statistically analysed. Results: Among the three experimental groups SEM analysis showed greatest efficacy of group IV at coronal and apical sections and statistically significant result at middle section. Conclusion: eucalyptol showed superior gutta percha removal efficacy at coronal and apical thirds and similar efficacy for both at middle third.

Efficacy of Protaper Universal, R Endo, Peezo Reamer on gutta percha removal: A stereomicroscopic analysis

Aim: The aim of this study is to compare the efficacy of Protaper Universal,R-Endo,Peezo Reamer for gutta percha removal during re-treatment by stereomicroscopic analysis. Materials and methods: A total of 20 extracted human maxillary single rooted teeth were selected. Canal preparation was carried out by the sequential use of K- files up to size 30 at working length and then divided into one control group(n=5)that is group I and three experimental groups II,III,IV (n=5 each).The experimental groups were obturated by lateral compaction of gutta percha using zinc oxide eugenol sealer. During retreatment xylene severed as solvent in all groups. In group II Protaper Universal ,group III R-Endo, group IV Peezo Reamer were used for gutta percha removal. Stereomicroscope was used to check the efficacy and statistically analysed. Results: Among the three experimental groups stereomicroscopic analysis showed greatest efficacy of group III at coronal, middle and apical sections when their summation was done. Conclusion: R-endo showed superior gutta percha removal efficacy over Protaper Universal and Peezo Reamer.

Comparison of apical sealability of AH plus and GuttaFlow sealers at three different levels of remaining gutta-percha in teeth prepared to receive posts: An In Vitro Study

Background and Objectives: To compare the apical sealing ability of AH Plus and GuttaFlow sealer at three different lengths of remaining gutta-percha after post space preparation. Method: 100 freshly extracted human maxillary anterior teeth were decoronated, biomechanically prepared and were randomly divided into six experimental groups and two control groups. The root canals were obturated using AH Plus sealer in first three groups and GuttaFlow sealer in other three groups. The positive control group was filled with lateral compaction of gutta-percha without sealer. In the negative control group, Canals were left unfilled. After one week, the post spaces were prepared to a depth that left 3, 4 and 5 mm of gutta-percha apically in groups 1, 2, 3 respectively and 4, 5, 6 respectively and the coronal parts of the canals were sealed with Glass Ionomer Cement. The apical leakage was assessed through dye penetration observed under a stereomicroscope and the obtained data was statistically analyzed. Results: AH Plus recorded a slightly higher mean microleakage compared to GuttaFlow, but the difference was not statistically significant. The interaction of the sealer and the length of remaining apical Gutta-percha on microleakage was not statistically significant. Conclusion: Irrespective of the type of sealer used, a 5 mm length of remaining apical gutta-percha filling provides a better seal than 3 mm and 4 mm.

Evaluation of thickness of hybrid layer and length of resin tags of three adhesives to the root canal dentin: An in vitro scanning electron microscopic study

Objectives: This present study was done to evaluate the resin-dentin interface of three adhesive systems used for bonding the root canal under scanning electron microscopic (SEM). Materials and Methods: Sixty single-rooted human maxillary anterior teeth were decoronated at the cementoenamel junction apical preparation done up to 60 no. K-file and obturated with cold lateral compaction of gutta-percha and resin sealer (AH Plus). The specimens were then randomly divided into four groups of 15 teeth each. Group I-Etch and rinse adhesive system Group II-Self-etch adhesive system Group III-Resin modified glass ionomer adhesive system Group IV-No adhesive system used (control). All the adhesive systems were light cured then fiber posts were luted with dual cure resin cement and the specimens were prepared for SEM examination at magnifications ×1500 and ×5000 at coronal, middle and apical thirds of root canal. Results: Statistical analysis was performed using one-way ANOVA followed by post-hoc Tukey's honestly significant difference test. Group I showed highly statistical significant difference when compared with other groups. Conclusion: Maximum thickness of hybrid layer and long resin tags were shown by etch and rinse adhesives followed by self-etch adhesives.

Success Rate of Single- versus Two-visit Root Canal Treatment of Teeth with Apical Periodontitis: A Randomized Controlled Trial

IntroductionThe aim of this study was to evaluate the outcome of single- versus 2-visit root canal treatment of teeth with apical periodontitis after a 2-year follow-up period. MethodsThree hundred maxillary and mandibular nonvital teeth with apical periodontitis were treated in either a single visit or 2 visits. The main inclusion criteria were radiographic evidence of apical periodontitis (minimum size ≥2.0 × 2.0 mm) and a diagnosis of pulpal necrosis confirmed by a negative response to hot and cold tests. Radiographically, all teeth showed small and irregular periapical radiolucencies before treatment. The canals were enlarged with LightSpeedLSX (Discus Dental, Culver City, CA) root canal instruments to a final apical preparation size #60 for anterior and premolar teeth and size #45 to #55 for molars. The EndoVac negative-pressure irrigation system (Discus Dental) was used for disinfecting irrigation, and all canals were filled by lateral compaction of gutta-percha and Sealapex sealer (SybronEndo, Orange, CA). The healing results were clinically and radiographically evaluated 2 years postoperatively. ResultsOf the 300 teeth treated, 18 were lost to follow-up, 9 in the 2-visit group and 9 in the 1-visit group. Of the 282 teeth studied, the randomization procedure had allocated 146 teeth to 1-visit treatment and 136 teeth to 2-visit treatment. Teeth with symptoms of persisting periapical inflammation were scored as not healed. Teeth with a reduced periapical rarefaction were judged as uncertain. Teeth with complete restitution of the periodontal contours were judged as healed. In the 1-visit group, 141 of 146 teeth (96.57%) were classified as healed as compared with 121 (88.97%) of 136 teeth in the 2-visit group. Eleven cases were classified as uncertain in the 2-visit group (8.08%) compared with 4 (2.73%) in the 1-visit group. Two of 10 teeth in the 2-visit group presented with pain before the 2-year follow-up and were classified as not healed. The hypothesis tests were conducted at the 0.05 level of significance. Statistical analysis of the healing results did not show any significant difference between the groups (P = .05). ConclusionsSeveral factors play an important role in the decision-making process of 1- versus 2-visit endodontics. Among these are objective factors like preoperative diagnosis, the ability to obtain infection control, root canal anatomy, procedural complications, and subjective factors like patients' signs and symptoms. This study provided evidence that with a treatment protocol with instrumentation to predefined larger apical instrumentation sizes and irrigation with a negative apical pressure system can lead to healing in cases of apical periodontitis, which is a significant finding compared with more dated studies that showed average healing of apical periodontitis cases. With the given sample size, there was no statistically significant difference between the 2 treatment modalities.

Comparative analysis of carrier-based obturation and lateral compaction: a retrospective clinical outcomes study.

The purpose of this retrospective study was to compare the outcome of primary endodontic treatment using a standardized cleaning and shaping technique and obturation with either lateral compaction or carrier-based obturation. Patients received primary endodontic treatment in the predoctoral dental clinic using a standardized cleaning and shaping protocol. All root canals were obturated using AH PlusTM sealer with lateral compaction of gutta-percha (LC) or carrier-based obturation (CBO). A total of 205 cases met the inclusion criteria. 71 teeth in 60 patients were recalled after 2 years and evaluated both clinically and radiographically by two independent examiners. Success was defined as a lack of clinical symptoms and a normal periodontal ligament space or reduction in size of a previously existing periapical radiolucency. Chi-square and logistic regression were used for statistical analysis with a significance level of P < 0.05. There was no difference in success rates between cases obturated with LC or CBO (P = 0.802); overall success rate was 83%. Molars had a significantly lower success rate (53%) than premolar and anterior teeth (89%) (P = 0.005), irrespective of the obturation technique used. When a standardized cleaning and shaping protocol was used by predoctoral dental students in a controlled university setting, there was no difference in success rates between cases obturated with LC or CBO.

Sealing ability of lateral compaction and tapered single cone gutta-percha techniques in root canals prepared with stainless steel and rotary nickel titanium instruments

Objectives: The aim of this study was to evaluate the sealing ability of lateral compaction and tapered single cone gutta-percha techniques in root canals prepared with stainless steel and rotary nickel titanium root canal instruments by fluid filtration method. Study design: The root canals were prepared with stainless steel (SS) and nickel titanium (NiTi) instruments. The canals prepared with SS were obturated with lateral compaction technique using .02 tapered cones and the canals prepared with NiTi instruments were obturated with lateral compaction technique using .02 tapered cones or 06 tapered single cones. The amount of leakage was evaluated by fluid filtration model. The results were statistically analyzed with one-way ANOVA. Results: The group prepared with NiTi instruments and filled with lateral compaction technique showed significantly less coronal leakage than the group prepared with SS instruments and filled with lateral compaction technique (p<0.05). There was no statistically difference between apical leakages of groups (p>0.05). Conclusions: Obturation with lateral compaction of gutta-percha provides a superior coronal seal whilst canal instrumentation with engine-driven NiTi files reduces the extent of microleakage in root canals when compared with stainless steel hand instruments. Tapered single cone technique was comparable with lateral compaction technique because of easier application. Key words:Apical leakage, coronal leakage, lateral compaction technique, single cone technique.

Impact of smear layer on sealing property of root canal obturation using 3 different techniques and sealers. Part I

The objective of this study was to determine the influence of smear layer removal on through-and-through fluid movement along root canal fillings obturated using 3 different root canal sealers, namely AH26, Pulp Canal Sealer, and Gutta-Flow, and 3 different obturation techniques. The fluid transport model was used for detection of through-and-through fluid movement. Root canals of 230 human extracted teeth were mechanically instrumented using the step-back technique. The canals where the smear layer was not removed were irrigated with NaOCl 2.4%, whereas canals where the smear layer was removed were irrigated with EDTA 17% plus NaOCl 2.4%. The teeth were randomly divided into 10 experimental groups (n = 20) and 3 control groups (n = 10) and treated as follows. In group A, where no attempt was made for smear layer removal, the canals were obturated with lateral compaction of gutta-percha and AH26 as a sealer. In group B, the smear layer was removed, and canals were obturated as in group A. In group C (no attempt to remove the smear layer), the canals were obturated with System B plus Obtura II technique and AH26, whereas in group D, the smear layer was removed, and canals were obturated as in group C. The other 4 experimental groups were treated and obturated in the same way as in previous groups, respectively. The sealer that was used in those groups was the Pulp Canal Sealer. Finally, the latter 2 groups were obturated with Gutta-Flow technique. Fluid movement was measured at 24 hours and 30 days and 6 months. In lateral compaction groups (with and without the smear layer), no significant differences were found regarding the ability of the same materials (AH26 and Pulp Canal Sealer) to prevent the fluid movement (P > .05). In warm obturation technique, no significant difference was found between the 2 groups (with and without the smear layer) of AH26 (P > .05). On the contrary, in groups of Pulp Canal sealer, fluid transport values were significantly less when the smear layer was removed (P < .05). Finally, no significant difference was observed between the groups of Gutta-Flow (with and without the smear layer) (P > .05). Under these in vitro conditions, it seems that smear layer removal improves the ability of the filling materials to prevent the fluid movement, at least after the use of warm obturation techniques. On the contrary, smear layer removal does not seem to improve the same ability after the use of cold lateral compaction technique. Further laboratory and also clinical studies are needed in the future to compose a clear view concerning the improvement of sealing ability following smear layer removal.

Coronal microleakage in intact and carious teeth obturated using lateral compaction of gutta-percha

Introduction: Coronal microleakage is one of the most important factors for the success and longevity of endodontically treated teeth. Aim: The aim of this study was to evaluate in vitro the coronal microleakage in carious and intact teeth obturated with lateral compaction of gutta-percha using the dye penetration method. Materials and Methods: Forty extracted human teeth were allocated to two groups: Group I consisted of 20 intact teeth (10 single-rooted and 10 multi-rooted) and Group II comprised 20 carious teeth (10 single-rooted and 10 multi-rooted). Root canal preparation was performed using the Step-back technique and copious irrigation with 2.5% NaOCl. All root canals were obturated using lateral compaction and AH Plus endodontic sealer. The teeth were coronally filled with either CAVIT only or the combination of GIC and CAVIT, coated with 2 layers of nail varnish and immersed in 50% AgNO3. Afterwards, the teeth were sectioned mesio-distally using a diamond disc and linear dye penetration was evaluated using a stereo loupe with a micrometer scale at x6 magnification. Results: The results showed dye penetration in 70% of teeth filled with CAVIT and in 10% of teeth filled with GIC+CAVIT. The difference was statistically significant (p&lt;0.05). Conclusion: Based on the obtained results, it may be concluded that the least coronal microleakage was observed in intact teeth temporarily filled with the GIC+CAVIT combination.

Sealing Ability of Four Materials in the Orifice of Root Canal Systems Obturated With Gutta-Percha

Failure to maintain the coronal as well as apical seal may expose obturated canals to microbes that could retard healing and create infection in the periodontal ligament or supporting osseous structures. 50 single rooted teeth (Type I canal anatomy) were randomly assigned to 4 experimental and 2 control groups. Ten specimens each were sealed with Mineral Trioxide Aggregate (MTA), Tetric Flow, Glass Ionomer Cement (GIC) and Light Cure Glass Ionomer cement (LC GIC). After creation of uniform orifice diameter, the smear layer was removed and the canal systems obturated using lateral compaction of gutta-percha (GP). GP was removed to the depth of 3.5 mm, experimental materials placed in orifice and the roots submerged in Rhodamine-B dye in vacuum for one week. Specimens were longitudinally sectioned and leakage measured using a 10X stereomicroscope and graded for depth of leakage. According to the result of the present study LC GIC demonstrated significantly better seal (p<.01) than MTA however there was no statistically significant difference in leakage (p>.01) between Tetric Flow, GIC and LC GIC and in between MTA, Tetric Flow and GIC.

Effectiveness of Different Obturation Techniques in the Filling of Simulated Lateral Canals

The purpose of this in vitro study was to evaluate the ability of lateral compaction of gutta-percha and of five thermoplasticized gutta-percha filling techniques to obturate simulated lateral canals. Sixty extracted single-rooted human teeth were instrumented at the working length to a #35 file before creating three simulated lateral canals on the mesial and distal surfaces of the root, one in each third, using a #15 engine reamer. After enlarging root canals to a #45 file, the teeth were randomly divided into six equal groups of 10 and obturated according to the following techniques: lateral compaction of gutta-percha (group A), hybrid technique (group B), Ultrafil (group C), Obtura II (group D), System B + Obtura II (group E), and Thermafil (group F). AH26 was used as the sealer. A greater number of simulated lateral canals were obturated when Ultrafil, Thermafil, and System B + Obtura II were used, in comparison with canals obturated with the hybrid technique, Obtura II, or lateral compaction of gutta-percha. This difference was statistically significant (p < 0.05). No statistically significant differences were found between results obtained in the obturation of simulated lateral canals in the different thirds of the root (p > 0.05).

Longitudinal study of the microleakage of two root-end filling materials using a fluid conductive system

A comparison of the microleakage of mineral trioxide aggregate (MTA) and a high copper admix amalgam (Valiant PhD) in root-end preparations was made using a fluid conductive device. Thirty-three bilaterally matched pairs of extracted, single-rooted teeth were prepared and obturated using lateral compaction of gutta-percha. The root-ends were resected and 3-mm-deep class I cavity preparations were made. The root-end preparations were filled with either amalgam or MTA. Guttapercha coronal to the root-end fillings was removed leaving only the amalgam or MTA present as a barrier to fluid movement. In the fluid-conductive device, the root canals were filled with a phosphate-buffered saline solution at a pressure of 10 psi. The flow of fluid was measured and compared at 1, 2, 3, 4, 8, 12, 16, 20, and 24 wk. The results showed amalgam to have significantly higher microleakage after 4 wk and higher variability compared with the MTA group.

The effect of immediate versus delayed dowel space preparation on the integrity of the apical seal

This in vitro study evaluated the effect of immediate vs delayed preparation of dowel space on the integrity of the apical seal. Twenty human teeth were obturated by lateral compaction of gutta-percha and cement and stored. Two weeks later, 20 more were similarly filled. Using warm endodontic pluggers, dowel spaces were prepared so that either 3 mm or 7 mm of apical fill remained. The specimens were treated in 45CaCl 2, horizontally sectioned, and autoradiographs were made. Analysis of the incidence and degree of microleakage showed that delayed preparations significantly increased leakage ( P <.01) if only 3 mm of apical fill remained.