Minimal Dentinal Tubule Penetration of Endodontic Sealers in Warm Vertical Compaction by Direct Detection via SEM Analysis

Sealer staining using rhodamine B dye to investigate the penetration depth of endodontic sealers was proven unsuitable for this purpose. This study aimed to investigate the sealer penetration depth into dentinal tubules by scanning electron microscopy (SEM). Root canals of 52 human upper central incisors were instrumented using the ProTaper Gold NiTi system (Dentsply Sirona, York, PA, USA) up to size F3. After irrigation with sodium hypochlorite and citric acid combined with ultrasonic activation, the root canals were either filled using the epoxy resin sealer AH Plus (Dentsply Sirona) or the calcium silicate-based sealer Total Fill BC Sealer HiFlow (TFHF, FKG Dentaire, La Chaux-de-Fonds, Switzerland) by warm vertical compaction. Root slices of 1 mm thickness were obtained at 2 to 3, 5 to 6 and 8 to 9 mm from the apex. The root slices were investigated for sealer penetration into the dentinal tubules using SEM according to four root quadrants (buccal, mesial, oral, distal). Statistical analysis was performed by the Kruskal-Wallis test (p = 0.05) as data were not normally distributed according to the Shapiro-Wilk test. AH Plus penetrated significantly deeper into the dentinal tubules compared to TFHF at each root level (p < 0.05). Dentinal sealer penetration was deeper in the bucco-oral direction compared to the mesio-distal direction. AH Plus penetrated deeper into dentinal tubules than TFHF. Warm vertical compaction exerting high pressure on the root canal filling material is not able to press sealers deep into dentinal tubules as penetration depth values did not exceed a mean of 110 µm in SEM.

Debris Extrusion Using Reciproc Blue and XP Endo Shaper Systems in Root Canal Retreatment

This study aimed at assessing the performance of Reciproc Blue (RB) and XP Endo Shaper (XPS), used for canal retreatment on extracted teeth, in terms of debris extrusion and obturating materials removal. Thirty mandibular premolars were prepared to ProTaper X2 file, obturated using warm vertical compaction, and then incubated for 28 days at 100% humidity at 37°C. Teeth were randomly assigned into two groups, according to the system used for retreatment (RB and XPS). During retreatment, debris extruded beyond the apex was collected in preweighed Eppendorf tubes, and the retreatment time was measured. Afterward, the teeth were longitudinally sectioned to assess the remaining obturating materials. Data were statistically analyzed using the Mann–Whitney test and chi-square test at a 95% confidence level. All the samples had extruded debris at varying weights ranging from 0.125 mg to 3.680 mg. XPS extruded less debris than RB, but no difference was detected (Mann–Whitney test; P > 0.05 ). RB and XPS required 54.9 ± 17.9 and 22.3 ± 9.3 seconds to perform retreatment procedures, respectively (Mann–Whitney test; P < 0.05 ). The sealer was found in all the samples. Compared to the RB group, fewer samples with remaining gutta-percha were found in the XPS group (Chi-square test; P < 0.05 ). None of the files fractured during the retreatment procedure. The tested files appear to extrude debris beyond the apex. Although XPS was able to remove the gutta-percha completely from the majority of the canals, it was unable to remove the sealer.

Impact of Warm Vertical Compaction on the Sealing Ability of Calcium Silicate-Based Sealers: A Confocal Microscopic Evaluation

The aim of this in vitro study was to evaluate the dentinal tubule penetration of two calcium silicate-based sealers used in warm vertical compaction (WVC) obturation technique in comparison with the single cone (SC) technique by confocal laser scanning microscopy (CLSM). The null hypothesis was that both obturation techniques produced similar sealer penetration depths at 1 and 5 mm from the apex. Forty-four mandibular single-rooted premolars were randomly divided into four equally experimental groups (n = 10) and two control groups (n = 2) according to the type of sealer (Bio-C Angelus, Londrína, PR, Brazil or HiFlow Brasseler, Savannah, GA, USA) with either SC or WVC. The sealers were mixed with a fluorescent dye Rhodamine B (0.1%) to enable the assessment under the CLSM. All the specimens were sectioned horizontally at 1 and 5 mm from the apex. The maximum penetration depth was calculated using the ImageJ Software (ImageJ, NIH). Data were analyzed by Mann–Whitney U and Kruskal–Wallis tests (p < 0.05). A significant difference was shown between the four groups at 1 mm (p = 0.0116), whereas similar results were observed at 5 mm (p = 0.20). WVC allowed better diffusion for both sealers at 1 mm (p = 0.01) and 5 mm (p = 0.034). The maximum penetration of the Bio-C and HiFlow sealers was more important at 5 mm with the two obturation techniques. Within the limitations of this study, WVC enhanced the penetration of calcium silicate-based sealers into the dentinal tubules in comparison with the SC technique at both levels.

Frequency, distribution and obturation technique of root canal retreatment among patients attending a teaching dental hospital in Chennai - A retrospective study

The aim of the study was to determine frequency, distribution and obturation technique of root canal retreatment among patients attending a teaching dental hospital in Chennai from June 2019 to March 2020. Three hundred seventy case records of endodontic retreatment were obtained, 262 met inclusion criteria. Patients above 18 years of age, patients who visited from June 2019 to March 2020 and patients who have already finished root canal treatment and had complaints of pain were included. Data were tabulated into excel sheets under the headings age, gender, teeth no, obturation technique. Then data were analyzed using SPSS software (23.0). The statistical analysis of the data was performed using chi-square test. Out of the 262 case sheets analysed, 64.9% were male and 35.1% were female. Most commonly affected age group was 18-30 years (38.5%), the least affected age group was above 60 years (6.9%). Most commonly affected teeth were 11,21 (26%,11.8%), least commonly involved were 17,27,32,33 (0.4% - 0.8%). Matched taper single cone technique was most commonly used (57.6%) followed by lateral compaction (40.5%), least commonly preferred technique was warm vertical compaction (1.9%). Overall results of the study are statistically not significant (P>0.05). Within the limitations of this study, it was concluded that the prevalence of retreatment cases was high in upper anterior teeth followed by lower posterior. Whereas the association of retreatment cases was least in upper posterior and lower left lateral and canines. Incidence of retreatment cases in relation to root canal treated teeth was higher in male among the 18 - 30 year's age group.

Post preparation: cleanness achieved by different irrigating protocols.

The aim of this study was to evaluate the ability of different irrigation protocols to remove from the walls of the root canal and entrance to dentinal tubules the smear layer produced during preparation for a fiber post. Fifty decoronated human lower premolars were treated endodontically and the apical third of the canal was filled with a single gutta-percha point using warm vertical compaction. Ten millimeters were left free for post preparation, which was done by sequential use of a Largo #1 drill and Exacto #3 pilot drill (Angelus, Brazil), with irrigation with distilled water upon each instrument change. Samples were distributed randomly into 5 groups (n=10). G 1: No irrigation after post preparation. G 2: Distilled water activated for 60 s + distilled water. G 3: 5.25% NaOCl 15 s+ distilled water. G 4: 17% EDTA (Farmadental, Argentina) 60 s + 5.25% NaOCl 15 s + distilled water. G 5: 10% polyacrylic acid (Densell) 15 s + distilled water. Irrigant was activated mechanically with a low-speed conical brush. Roots were then split longitudinally in vestibular-lingual direction. Each surface was observed under SEM in its different thirds. Microphotographs were taken at 150X and 600X magnification and results analyzed statistically using Kruskall Wallis and Friedman tests (p<0.05). The results [mean (standard deviation)] were: for 150X: G1 11.00 (1.33), G2 7.50 (3.13), G3 6.30 (2.58), G4 2.20 (2.80), G5 4.30 (1.50), and for 600X G1 11.40 (0.84), G2 10.00 (1.94), G3 7.70 (3.33), G4 5.80 (3.70), G5 7.20 (2.65). The statistical analysis showed significant differences between irrigants (p<0.05) but not between root thirds (p>0.05). The EDTA+NaOCl combination and polyacrylic acid showed greater capacity to remove the smear layer created during post preparation.

EFFECTS OF COLD LATERAL VERSUS WARM VERTICAL COMPACTION OBTURATION ON THE PUSH-OUT BOND STRENGTH OF BIOROOT™, A CALCIUM SILICATE-BASED SEALER

Objective: BioRoot™ , which contains pure calcium silicate, is used in cold lateral compaction. However, hydroxyl ions are still released when BioRoot™is used in warm vertical compaction. This study compared the effects of cold and warm vertical compaction obturation on the push-out bond strengthof BioRoot™.Methods: Specimens from 16 root canals instrumented with ProTaper Next X5 50/06 were divided into two groups (n=16 specimens per group).Group 1 was obturated using cold lateral compaction, whereas Group 2 was obturated using warm vertical compaction. All samples were incubatedfor 48 h (37°C, 100% humidity) and embedded into an acrylic block. Starting at 7 mm from the apex, two 2-mm-thick slices of each sample were cut.Dislodgement resistance was measured using a universal testing machine, and the push-out bond strength was calculated.Results: There was a significant difference in the push-out bond strength value between cold (4.5–41.1 MPa) and warm (4.12–24.25 MPa) compactionobturation (p<0.05).Conclusion: Cold lateral compaction provides better adhesion capability than warm vertical compaction in root canal obturation.

Lower First Permanent Molar with an Additional Root Diagnosis and Management

Three rooted lower first permanent molar represents one of the main anatomical variants which is a treatment challenge of clinicians. This study is aimed at presenting a case of a lower first molar with an additional root that was diagnosed and managed successfully using new techniques in endodontics. Tooth #46 was diagnosed as a necrotic pulp with symptomatic apical periodontitis. Different angle radiographs were obtained, and they clearly showed three roots. The procedure was completed under magnification and illumination using an operating microscope. The access cavity was modified to achieve straight line access for all the canals. Careful step-by-step instrumentation was performed using flexible NiTi rotary files. The canals were irrigated using 6% sodium hypochlorite. Afterwards, three-dimensional obturation was completed using warm vertical compaction. Knowledge of the anatomy and an early diagnosis are required to achieve high-quality root canal treatment.