Comparison of penetrating depth of chlorhexidine and chitosan into dentinal tubules with and without the effect of ultrasonic irrigation.

BACKGROUND: Long term success of root canal treatment depends on complete removal of micro-organisms and their by-products. This can be effectively achieved by the ability of the irrigant to penetrate into the dentinal tubules, which is limited in the conventional mechanical debridement of the root canal system. Irrigant activation technique aids in movement of irrigants into the dentinal tubules. AIM: To compare the depth of penetration of root canal irrigants into the dentinal tubules with and without ultrasonics using light microscope. MATERIALS AND METHODS: Forty noncarious mandibular premolars were used, all the tooth specimens were inoculated with an ATCC 29212 strain of E.faecalis and incubated under nutrient rich aerobic conditions at 37°C. Teeth were sectioned below the cementoenamel junction to obtain a standard length of 8 mm and instrumented with K-files, irrigated with 5.25% sodium hypochlorite and a final rinse of 17% EDTA. Teeth were divided into four groups of ten each. Group IA was irrigated with 2% Chlorhexidine (CHX) and agitated ultrasonically, Group IB was irrigated with 2% Chlorhexidine, Group IC was irrigated with 2% Chitosan and ultrasonically agitated, Group ID was irrigated with 2 % Chitosan. The tooth specimens were sectioned and subjected to gram staining and viewed under 100X oil immersion microscope. A micrometer grid was attached to the eyepiece to enable measurement of the depth of penetration of the irrigants. Group IA (2% Chlorhexidine with ultrasonic agitation) showed better penetration into the dentinal tubules as compared to Groups IB, IC, ID. RESULTS: Irrigation with 2% Chlorhexidine with ultrasonic agitation had depth of penetration into the dentinal tubules upto 2350 µm. 2% Chlorhexidine without ultrasonic agitation penetrated upto 1800 µm. Chitosan with ultrasonic agitation penetrated upto1250 µm and Chitosan without ultrasonic agitation penetrated upto 44.80 µm. CONCLUSION: 2% Chlorexidine as irrigant with ultrasonic agitation was found to have maximum depth of penetration into the dentinal tubules when compared with Chitosan.

Endodontic Management of Dilacerated Maxillary Central Incisor fused to a Supernumerary Tooth using Cone Beam Computed Tomography: An Unusual Clinical Presentation.

AIM: The purpose of this report is to present a case of endodontic management of a dilacerated maxillary central incisor fused to supernumerary tooth unusually appearing as a labial tubercle using cone beam computed tomography (CBCT) as a diagnostic aid. BACKGROUND: Anterior teeth are commonly encountered with aberrant anatomical variations in the crown, number of roots, and root canals. Fusion is an infrequent developmental abnormality in shape of the tooth caused by the union of two adjacent tooth germs. A complete knowledge of such complex anatomies is mandatory for a successful root canal treatment. It highlights the endodontic and restorative approach in the functional and esthetic rehabilitation of the involved tooth. CASE REPORT: Three-dimensional imaging using CBCT was used in this case to differentiate single labial canal and palatal C-shaped canal. The endodontic treatment was performed with the aid of dental operating microscope, and the root canals were obturated with a combination of single cone, carrier based, and cold flowable gutta-percha obturation system. The tooth remained asymptomatic without reinfection and symptoms of failure for 18 months. CONCLUSION: Cone beam computed tomography is indispensable in treatment planning for cases where the radiographs cannot reveal useful information regarding the root canal shape. Postobturation CBCT has helped in avoiding further retreatment of the tooth, which otherwise is a challenging task. CLINICAL SIGNIFICANCE: The use of sophisticated equipment, such as dental operating microscope and CBCT has helped in accurate diagnosis and treatment planning of fused central incisor respectively.

Effect of ethylene diamine tetra-acetic acid, MTAD™, and HEBP as a final rinse on the microhardness of root dentin.

CONTEXT: Evaluation of microhardness of root dentin provides indirect information on the change in mineral content of root dentin thereby providing useful information on the bonding quality of resin-based root canal sealers. AIM: This study evaluated the effect of 17% EDTA, MTAD, and 18% HEBP solutions on the microhardness of human root canal dentin using the Vickers microhardness test. MATERIALS AND METHODS: Forty human single-rooted teeth were decoronated at the cementoenamel junction and sectioned longitudinally into buccal and lingual segments. Eighty specimens were divided into four groups (n=20). Group I was treated with distilled water (control), groups II, III, and IV were treated with 1.3% NaOCl as a working solution for 20 minutes followed by 17% EDTA, MTAD, and 18% HEBP respectively. The surface hardness of the root dentin was determined in each specimen with a Vicker's hardness tester. The values were statistically analyzed using the one-way ANOVA and post hoc Tukey multiple comparison tests. RESULTS: There was a statistical significant difference among all the groups (one-way ANOVA; P<0.001). Among the experimental groups, HEBP showed the highest dentin microhardness (53.74 MPa, P<0.001). Least microhardness was found with MTAD (42.85 MPa, P<0.001). CONCLUSIONS: HEBP as a final rinse appears to be a promising irrigation protocol with less impact on the mineral content of root dentin.

Bactericidal effect of the 908 nm diode laser on Enterococcus faecalis in infected root canals.

AIM: The aim of this study is to evaluate the bactericidal effect of 908 nm diode laser in conjunction with various irrigation regimes in disinfection of apical third of root dentin. MATERIALS AND METHODS: Sixty prepared teeth with single canals were contaminated with Enterococcus faecalis. The specimens were divided into 6 groups (n = 10): Group 1 and 3 and 5 were subjected to chemo-mechanical preparation using 5.25% sodium hypochlorite (NaOCl), 17% Ethylenediaminetetraacetic acid (EDTA); 1.3% NaOCl, MTAD (mixture of doxycycline, citric acid and a detergent (Tween 80); and, 8.5% saline, respectively followed by 908 nm diode laser irradiation; Group 2 and 4, followed the same procedure as Group1 and 3, however without laser irradiation; and, Group 6, rinsed with saline solution (control). Dentin shavings from apical third were analyzed for the presence of E. faecalis using culture method and Polymerase Chain reaction (PCR). RESULTS: One-way Analysis of variance showed statistically significant differences between the laser irradiated groups, non irradiated groups and the control group. CONCLUSION: 908 nm diode used in conjunction with conventional chemomechanical techniques demonstrated a significant elimination of E. faecalis in the apical third of root dentin.

Effects of various final irrigants on the shear bond strength of resin-based sealer to dentin.

AIM: This study has been designed to evaluate the effect of strong (MTAD) or soft (1- hydroxyethylidene - 1, 1-bisphosphonate (HEBP) final irrigating solution on the shear bond strength of AH plus sealer to coronal dentin. 17% EDTA was used as the reference. MATERIALS AND METHODS: Forty freshly extracted human maxillary first premolars were prepared using different irrigation protocols (n=10). All the test groups had 1.3% NaOCl as initial rinse and followed by specific final rinse for each group: G1 - distilled water(control), G2 - 17% EDTA, G3- 18% HEBP and G4 - MTAD. Sections of polyethylene tubes that are 3mm long were filled with freshly mixed sealer and placed on the dentin surfaces. The bonding between the sealer and dentine surface was evaluated using shear bond testing. The values were statistically evaluated using one-way ANOVA followed by Tukey's test. RESULT: Significant difference was found among the irrigating regimes. EDTA showed highest bond strength followed by HEBP and MTAD.

Comparison of laterally condensed, vertically compacted thermoplasticized, cold free-flow GP obturations - A volumetric analysis using spiral CT.

AIM/OBJECTIVE: To compare the laterally condensed gutta-percha, vertically compacted thermoplastized gutta-percha (E and Q Plus system) and cold free-flow gutta-percha (GuttaFlow). This is a volumetric analysis using spiral CT, an in vitro study. MATERIALS AND METHODS: Access cavities were prepared in 60 single rooted anterior teeth; cleaning and shaping was done and obturated with three of the different techniques: group A: cold lateral; group B: vertically compacted thermoplasticized and group C: cold free-flow obturation techniques. Volume analysis was done using spiral computed tomography (CT). The percentage difference was calculated and statistically analyzed using one-way ANOVA and post hoc multiple comparison Tukey HSD tests. RESULTS: There were statistical significant differences between group A (0.183cm(3)) and group B (0.136cm(3)); group A (0.183cm(3)) and group C (0.128cm(3)). But there was no statistical significance between group B (0.136cm(3)) and group C (0.128cm(3)). CONCLUSION: Within the limitations of this in vitro study it can be concluded that cold free-flow obturation technique showed the highest volume of obturation, followed by the vertically condensed thermoplasticized technique. The least volume of obturation was observed in cold lateral condensation technique.