Sarika Chaudhry

Comparison of physical and mechanical properties of mineral trioxide aggregate and Biodentine

BACKGROUND Mineral trioxide aggregate (MTA) fulfills many of the ideal properties of the root-end filling material. However, its low cohesive property often makes it difficult to handle. Biodentine, new calcium-silicate-based cement has been developed to improve some MTA drawbacks such as its difficult handling property and long-setting time. AIM The objective of this study was to compare at different times the microleakage of roots filled with Biodentine and white MTA (WMTA)-Angelus and to investigate their setting time, handling properties and compressive strength. MATERIALS AND METHODS Root canals of single-rooted teeth were instrumented, filled with either Biodentine or WMTA-Angelus (n=15 each) with two positive and two negative control roots and stored at 37°C. Sealing was assessed at 4, 24 h, 1, 2, 4, 8, and 12 weeks by a fluid filtration method. The initial setting time, handling properties, and compressive strength of the test groups were investigated by a vicat needle, questionnaire of operational hand feel, and universal instron machine, respectively. RESULTS Significant differences in microleakage were found between two groups at 4-h and 24 h (P<0.05) and no difference at 1, 2, 4, 8, and 12 weeks. No significant difference was seen in the setting time of MTA-Angelus and Biodentine, though latter was found to have better handling consistency. Compressive strength of Biodentine was significantly higher than MTA-Angelus. CONCLUSIONS The results suggest that the new calcium-silicate-based endodontic cement provides improvement in sealing ability as well as clinical manageability of dental filling materials.

Endodontic management of open apex using MTA and platelet - rich fibrin membrane barrier: A newer matrix concept.

Objectives: Endodontic management of open apex using MTA and platelet – rich fibrin membrane as an apical matrix barrier. Study design: An immature tooth with pulpal necrosis and periapical pathology imposes a great difficulty to the endodontist. Endodontic treatment options for such teeth consist of conventional apexification procedure with and without apical barriers. This article demonstrates the use of an apical matrix barrier in form of a platelet rich fibrin membrane for stabilization of MTA in root end apexification procedure. PRF is an autologous fibrin matrix containing a large quantity of platelet and leukocyte cytokines, which enhance healing by release of growth factors. These case reports present apexification and successful healing with combined use of MTA and PRF membrane as an apical barrier Results: PRF membrane can serve as an efficient apical matrix for condensation of MTA. Combination of PRF membrane and MTA is an effective method for management of difficult cases of open apex. PRF is a strong fibrin membrane enriched with platelet and growth factors that accelerate periapical healing. Key words:Apexification, apical barrier, platelet rich fibrin (PRF), mineral trioxide (MTA).

Evaluation of Biocompatibility and Osteogenic Potential of Tricalcium Silicate–based Cements Using Human Bone Marrow–derived Mesenchymal Stem Cells

Introduction: The success of endodontic regeneration lies in the appropriate combination of stem cells and bioactive materials. Several novel dental materials are available on the market in this regard. Hence, the current study aimed to evaluate the proliferation, differentiation, and osteogenic potential of human bone marrow–derived mesenchymal stem cells (hBMSCs) onto biomaterials like ProRoot MTA (MTA; Dentsply Tulsa Dental, Tulsa, OK), Biodentine (BD; Septodont, Saint Maur de Fosses, France), and EndoSequence Root Repair Material (ERRM; Brasseler USA, Savannah, GA). Methods: Dental cements were formulated into discs and assessed for their biocompatibility. hBMSCs were used to study biocompatitibility and the proliferative and osteogenic potential of these dental cements. A live dead assay was performed using confocal microscopy to study the biocompatibility, proliferation, and cell attachment property of the cements. An 3‐(4,5‐dimethylthiazol‐2‐yl)‐2,5‐diphenyltetrazolium bromide assay was also performed on days 1, 3, 5, and 7 to study growth kinetics. The osteogenic potential of these cements was studied by inducing hBMSCs over them using osteogenic differentiation medium (assessed by alkaline phosphatase assay). Results: ERRM and MTA have shown the best biocompatibility among the tricalcium silicate materials used with no significant difference between them. Both have shown significantly higher osteogenic bioactivity than BD. All 3 tricalcium silicate cements support good adherence of hBMSCs. Conclusions: All of the dental cements used in this study are biocompatible with the potential to induce proliferation and osteogenic differentiation of hBMSCs. Therefore, the newly introduced ERRM can be the material of choice in various endodontic applications.

Correction of gummy smile using digital smile designing in conjugation with crown lengthening by soft-tissue diode laser

The digital smile design (DSD) is a software-based system which has been recently introduced in the field of dentistry. It is a precise and efficient method for esthetic rehabilitation as it allows the clinician to visualize and estimate discrepancy of orofacial and dentogingival tissues. This case report presents an interdisciplinary treatment approach for esthetic correction of a 20-year-old female patient who presented with a chief complaint of gummy smile. Through the application of digital smile designing principle, the necessary corrections for achieving a harmonic smile were accurately determined. Wax-up of the master cast was done accordingly. Gingival portion of the master cast was duplicated in clear acrylic resin. This temporary stent guided the gingival contouring which was done using soft-tissue diode laser. Diode laser was found to be safe and useful for soft-tissue management as it ablates soft tissues very precisely, and the wound healing is more favorable. We conclude that the DSD in combination with diode laser seems to be a useful tool to achieve a satisfactory esthetic result, especially in the management of esthetically demanding cases of gummy smile.

Effect of EndoActivator and Er,Cr:YSGG laser activation of Qmix, as final endodontic irrigant, on sealer penetration: a confocal microscopic study

Background Through chemomechanical debridement of the root canal is a primary requisite for successful endodontic therapy. Thus the aim of this study was to evaluate the effects of using QmiX alone, QmiX with EndoActivator and QmiX with Er,Cr:YSGG laser for final irrigation on sealer penetration into the dentinal tubules. Material and Methods 75 extracted human mandibular premolar teeth were treated with sodium hypochlorite (NaOCl) irrigation. The samples were divided into 5 groups according to the final irrigation solution used: (1) 17% EDTA and 2.5% NaOCl, (2) QmiX (3) QmiX with Er,Cr:YSGG laser and (4) QmiX with EndoActivator (5) 2.5%NaOCl. All teeth were obturated using cold lateral condensation technique with gutta percha and AH 26 sealer (Dentsply; DeTrey,Konstanz, Germany) labeled with Rhodamine B dye. The teeth were sectioned at distances of 2 and 5 from root apex. Total percentage and maximum depth of sealer penetration were measured using confocal laser scanning microscopy. Results Results of one way Anova analysis showed that there was a significant difference in the percentage and depth of sealer penetration among all groups at 3 and 5 mm level sections (P < .05). Within the groups maximum sealer penetration was recorded for Er,Cr:YSGG laser activated group. Greater depth of sealer penetration was recorded at 5mm as compared to 3mm in all the groups. Conclusions Activation of QMix using EndoActivator and Er,Cr:YSGG laser enhanced the sealer penetration at apical and middle third. Thus Er,Cr:YSGG laser and EndoActivator may act as an appropriate adjunct during chemomechanical preparation of the root canal. Key words:EndoActivator, Er,Cr:YSGG laser, Qmix, confocal microscopy, sealer penetration.

Effect of acid etching on the micro-shear bond strength of resin composite–calcium silicate interface evaluated over different time intervals of bond aging

Introduction: With the introduction of calcium silicate materials, pulp capping procedure has been simplified due to their therapeutic pulp capping capabilities and ability to be used as a provisional bulk restorative material simultaneously. The quality of the adhesive bond between these cements and composite is of clinical significance with regard to the longevity of the final laminate restoration. Thus, this study aims to compare the in vitro microtensile bond strengths of resin composite to different calcium silicate cements versus glass ionomer cement (GIC). Materials and Methodology: Resin composite was bonded to standardized disks of Biodentine, mineral trioxide aggregate (MTA), and GIC. The samples were divided into the following three groups, and each group was further divided into two subgroups based on the aging time (1 and 2 weeks) of the samples: (1) Group 1 – phosphoric acid etching on Biodentine. (2) Group 2 – phosphoric acid etching on MTA. (3) Group 3 – phosphoric acid etching on GIC. After bond aging, the microtensile bond strength was analyzed using the Instron universal testing machine. Results: There was no significant difference in micro-SBS between 1- and 4-week bond aging of MTA and Biodentine group, while a significant decrease is seen in the GIC group. Conclusion: Calcium silicate cements are weak in the early setting phase. Thus, placing the overlying composite is best delayed for at least 2 weeks to allow adequate maturation of the material.

Evaluation of root-end cavity preparation using erbium, chromium:yttrium, scandium, gallium, and garnet laser, ultrasonic retrotips, and conventional burs

Aim: To compare root-end cavities prepared with ultrasonics (Group A), with those created by burs in a conventional handpiece (Group B) and erbium, chromium:yttrium, scandium, gallium, and garnet (Er, Cr:YSGG) laser (Group C). Materials and Methods: After root canal instrumentation and filling, apices of 60 single-rooted teeth were resected. Retrograde Class I cavities 3 mm deep were prepared using ultrasonic retro-prep tips (Group A), round burs (Group B), and Er:YSGG laser (Group C). An ultrasonic unit was used with computed tomography-5 retrotip at the frequency of 32 KHz. Laser beam parameters were a pulse of very short duration (100 s), energy of 280 mJ, and repetition rate of 10 Hz. The apical root portion and root-end cavities were replicated and prepared for stereomicroscopic analysis. Results: The degree of chipping associated with the margin of the root-end cavities and the incidence of root face cracks were noted. Marginal chipping of root-end cavities prepared using ultrasonic instrumentation was significantly higher than that produced by bur (P < 0.001) or laser, with laser group showing the least amount of chipping. Conclusion: There was a significant difference between the number of cracks produced by the three methods, with the laser group having the least number of cracks and marginal chipping.