Effect of acidic pH on microhardness and microstructure of theraCal LC, endosequence, mineral trioxide aggregate, and biodentine when used as root repair material.

INTRODUCTION: The aim of this study was to investigate the microhardness and microstructural features of newer tricalcium silicate materials: TheraCal LC, mineral trioxide aggregate (MTA), biodentine (BD), and Endosequence Root Repair Material (ERRM) putty, after exposure to acidic environments in comparison with distilled water. MATERIALS AND METHODS: A total of 80 extracted single-rooted premolars were collected. All the selected specimens were sectioned vertically, and cavities were prepared on the root surface. Specimens were divided into four groups of 20 each, i.e., Group 1: (n = 15) MTA (ProRoot, Dentsply Tulsa Dental, Tulsa, OK, USA), Group 2: (n = 15) BD (Septodont, France), Group 3: (n = 15) ERRM putty (Brasseler, USA), and Group 4: (n = 15) TheraCal LC (Bisco Inc Schaumburg). Materials were placed into prepared cavities. About 10 specimens per each group were exposed to butyric acid buffered at a pH level of 5.5 for 7 days at 37c, and 10 specimens from each group were exposed to distilled water serving as a control group. The surface microhardness was measured after exposure to either acid or distilled water. Scanning electron microscope was used to observe the internal microstructure morphology. Two-way analysis of variance was applied to evaluate the Knoop microhardness value (KHN). RESULTS: Results showed that the microhardness values of the materials were significantly higher in the neutral environment of butyric acid at pH 7.4 when compared to those in the acidic condition of pH 5.4 for all groups (P < 0.001). TheraCal LC had higher microhardness values than BD, MTA, ERRM putty at 5.5 pH levels (P < 0.001). CONCLUSION: The microhardness values of TheraCal LC, BD, ERRM Putty, and MTA were reduced in an acidic environment, which resulted in these materials having more porous and less crystalline microstructures. TheraCal LC seems the most suitable material for application to an area of inflammation where a low pH value may exist.

Atypical anatomy of maxillary second premolar with three roots and four canals.

Knowledge and understanding the anatomical configuration of individual tooth play a significant role in success of endodontic treatment, in addition to through debridement and obturation of the canals. The canal anatomy of maxillary second premolar has been studied extensively, and the presence of a significant variety of multirooted canals is relatively rare in it. A 27-year-old female reported with a chief complaint of pain in her upper right posterior region for 10 days. On intraoral hard tissue examination, ill-defined access preparation was seen in maxillary right second premolar with exposed pulp. An intraoral periapical radiograph reveals radiolucency involving the pulp space and varied morphology in the same tooth. The occurrence of three roots with four canals in the maxillary second premolar is rare and not documented in the literature so far. This case report describes the nonsurgical endodontic management of such varied anatomical configuration using cone beam computed tomography as an evaluating diagnostic tool.

Comparison of bond strength of different endodontic sealers to root dentin: An in vitro push-out test.

AIM: To compare the bond strength of four different endodontic sealers to root dentin through push-out test design. MATERIALS AND METHODS: Forty single-rooted teeth with completely formed apices were selected. Teeth were decoronated, and working length was determined. Instrumentation and irrigation were performed. The teeth were divided into four groups based upon the sealer used. Group 1: Bioceramic sealer (Endosequence), Group 2: Mineral trioxide aggregate (MTA) based sealer (MTA Fill apex), Group 3: Epoxy resin based sealer (MM-Seal), and Group 4: Dual cure resin-based sealer (Hybrid Root Seal). Manipulation and application of the sealer was done as per the manufacturer instructions. All the teeth were obturated using 6% gutta-percha. After obturation, each tooth was prepared for push-out test with root slices of 2 mm thickness using universal testing machine. RESULTS: The highest bond strength was found in Group 1 (Endosequence) (P < 0.05) compared to other groups. The lowest bond strength was found in Group 2 (MTA Fill apex). Statistical analysis is done by two-way ANOVA and Newman-Keuls multiple post hoc. CONCLUSION: The push-out bond strength of Bioceramic sealer was highest followed by resin-based sealer and lowest bond strength was observed in MTA-based sealer.

Marginal adaptation of newer root canal sealers to dentin: A SEM study.

AIM: This in vitro study evaluated and compared the marginal adaptation of three newer root canal sealers to root dentin. MATERIALS AND METHODS: Thirty freshly extracted human single-rooted teeth with completely formed apices were taken. Teeth were decoronated, and root canals were instrumented. The specimens were randomly divided into three groups (n = 10) based upon the sealer used. Group 1 - teeth were obturated with epoxy resin sealer (MM-Seal). Group 2 - teeth were obturated with mineral trioxide aggregate (MTA) based sealer (MTA Fillapex), Group 3 - teeth were obturated with bioceramic sealer (EndoSequence BC sealer). Later samples were vertically sectioned using hard tissue microtome and marginal adaptation of sealers to root dentin was evaluated under coronal and apical halves using scanning electron microscopy (SEM) and marginal gap values were recorded. RESULTS: The data were statistically analyzed by two-way ANOVA and Tukey's multiple post hoc test. The highest marginal gap was seen in Group 2 (apical-16680.00 nm, coronal-10796 nm) and the lowest marginal gap was observed in Group 1 (apical-599.42 nm, coronal-522.72 nm). Coronal halves showed superior adaptation compared to apical halves in all the groups under SEM. CONCLUSION: Within the limitations of this study epoxy resin-based MM-Seal showed good marginal adaptation than other materials tested.

Microleakage evaluation around retrograde filling materials prepared using conventional and ultrasonic techniques.

INTRODUCTION: The importance of the retrograde cavity preparation and the material used to restore is of utmost importance to achieve successful surgical endodontics. AIM: The aim of the present study is to evaluate the apical micro-leakage of root end cavities filled with Mineral trioxide aggregate, Biodentine and light cure GIC using two different cavity preparation techniques that is conventional bur preparation and ultrasonic tip preparation. MATERIALS AND METHODS: Eighty extracted single rooted human teeth (except mandibular incisors) with one canal, fully developed apices and without any major carious lesion are collected for the study. The teeth were sectioned at CEJ to standardize the length. Roots are instrumented upto master apical file 40 K size and obturated with gutta percha and AH plus sealer in lateral condensation technique. The teeth were then resected apically at 90° angle axis to the long axis of the root removing 3 mm of the apex. The teeth were divided in to four groups of 20 each- • Group I- samples restored with MTA. • Group II- samples restored with Biodentine. • Group III- (Positive control group)- samples restored with Light activated GIC. • Group IV - (negative control group)- no filling material. Each group is divided into two subgroups (a, b) of ten teeth each 1. Retropreparation done with ultrasonic retrotip. 2. Retropreparation done with conventional bur. The teeth were then immersed in 0.5% Rhodamine B dye for 48 h. The teeth were split longitudinally and the interface between the restored material and the canal wall is observed under Confocal laser scanning microscope. Depth of dye penetration was examined under stereomicroscope. RESULTS: The statistical analysis was performed by One way ANOVA, t test. Pair wise comparision was done by Newman - Keuls multiple post hoc test. The mean values of Dye penetration for Group Ia (321.23), Group Ib (490.11), Group IIa (1065.14), Group IIb (1170.96), Group IIIa (1888.90), Group IIIb (2025.35). The samples prepared with ultrasonic retrotip showed less microleakage but it is statistically not significant. CONCLUSION: MTA showed significantly less microleakage when compared to Biodentine and light cure GIC and there is no statistical difference between the ultrasonic retrotip preparation and conventional bur preparation.

A novel technique for removal of broken instrument from root canal in mandibular second molar.

The fracture of an endodontic instrument is an obstacle in completion of a routine successful pulp space therapy. Ni-Ti instruments corrode when in contact with sodium hypochlorite which leads to their deterioration and ultimately fracture during use. Removal of separated instrument from root canal is often a very difficult procedure. This procedure is more complicated when the instrument separated is closer to the mandibular canal. A case is presented in which a separated hand instrument was retrieved from the mesio buccal of a second molar approximating the mandibular canal root by replantation.

Effect of final irrigating solution on smear layer removal and penetrability of the root canal sealer.

OBJECTIVE: To evaluate the effect of final rinsing solution on smear layer removal through penetrability of the root canal sealer. MATERIALS AND METHODS: Each of the 30 teeth selected was decoronated and the root length standardized at 16 mm measured from the apex of the tooth to the cementoenamel junction (CEJ). A size 10-k file was used and working length was determined by subtracting 1mm from the measured length so that the length of the sample was 15mm. A combination of step back and crown down technique was done and apical portion was prepared till H-file no. 30. 3% NaOCl was used during cleaning and shaping of the canals. Finally the teeth were divided into three groups of 10 teeth each. Group-I was irrigated with 17% EDTA, Group-II with TUBLICID plus, and Group-III with Biopure MTAD(®). ISO 30 size gutta-percha points were selected as master cones. The Acroseal sealer was mixed with approximated concentration 0.1% fluorescent rhodamine B isothiocyanate dye. Obturation was done and after 48 hours, the roots were sectioned and subjected to confocal laser scanning microscopy. RESULTS: Comparisons among the three groups were done by two-way analysis of variance (ANOVA) and Newman-Keuls multiple post-hoc procedures. The two-way ANOVA showed statistically highly significant results. The maximum depth of sealer penetration was observed in Group II followed by Group III and Group I. CONCLUSION: The use of -Tubulicid plus as a final irrigant provided better smear layer removal than Biopure a mixture of doxicycline, citric acid and a detergent (Tween 80) (MTAD(®)) and 17% EDTA.

Evaluation of Correlation Between apical Diameter and File Size Using Propex Pixi Apex Locator.

AIM: AIM of this study is to evaluate the influence of critical diameter of apical foramen and file size using propex pixi apex locator in working length determination. MATERIALS AND METHODS: In this study, ten single rooted teeth were selected. They were decoronated at cemento enamel junction. After determining the actual working length, they were embedded in alginate mold. Foramina were widened from 0.6mm to 0.8mm. The measurements were taken with electronic apex locator propex pixi with files from sizes 10 K to respective sizes. Statistical accuracy of propex pixi was calculated by using Anova test for different diameters and for the influence of file size. RESULTS: RESULTS showed that propex pixi apex locator was accurate when foramen diameter is 0.6 (60k file size), its accuracy diminished with increased foramen diameter CONCLUSION: Propex pixi is accurate for foramen diameter of 0.6mm, independent of file size. Its accuracy decreases as apical foramen widens, so care should be taken when using clinically.

Antibacterial efficacy of sodium hypochlorite with a novel sonic agitation device.

OBJECTIVE: The aim of this study is to evaluate the antibacterial efficacy of 3% sodium hypochlorite (NaOCl) with sonic agitation devices. MATERIALS AND METHODS: Fifty extracted human single-rooted teeth were collected. Canals were prepared up to Profile #35/0.06. Forty teeth were inoculated with Enterococcus faecalis and incubated for 24 hours. The teeth were then divided into five groups based on the agitation device used. Group 1- was agitated with EndoActivator. Group 2 was agitated with Waterpik Power Flosser. In Group 3, Waterpik flosser was used with a nickel-titanium file. Group 4 (positive control) was not subjected to any agitation, and Group 5 -was the negative control. Superficial and deep dentinal shavings were collected from coronal and apical halves and sowed in brain heart infusion (BHI) agar to evaluate colony-forming units (CFU/mL). RESULTS: Krusal Wallis, analysis of variance (ANOVA) and Mann-Whitney U test showed that Group 3 showed a smaller number of CFUs/mL Group 2 showed a relatively greater number of CFU/mL. The deep apical dentin areas showed more number of CFUs relative to other sites. CONCLUSION: The nickel-titanium file attached to the Waterpik Power Flosser system was found to be as effective as the EndoActivator in antibacterial efficacy against E.faecalis.