Evaluation of Effectiveness of Intracanal Medicaments on Viability of Stem Cells of Apical Papilla.

INTRODUCTION: Regeneration, in the field of endodontics, is the process of restoring and maintaining both architectural form and biological functions of damaged tooth. Presently, regenerative endodontics is not hypothetical and is an alternative to conventional apexification procedures. There is a deficient knowledge concerning the role of intracanal medicaments and their effect on dental stem cells. AIM: The aim of this study was to evaluate the effectiveness of commonly used intracanal medicaments on the viability of dental stem cells of the apical papilla (SCAPs). MATERIALS AND METHODS: SCAPs were cultured and subjected to various concentrations including triple antibiotic paste, double antibiotic paste, Augmentin, and calcium hydroxide (Ca(OH)2). Viable percentage of stem cell counts was obtained 3 days after treatment. RESULTS: All three antibiotics used hereby significantly decreased SCAP cell survival at particular concentrations, whereas Ca(OH)2 showed stimulating effect on SCAP survival. CONCLUSION: As per results obtained within limitations of this study, use of Ca(OH)2 in regenerative endodontics in comparison to different commonly used antimicrobial combinations is recommended. Hereby, for clinical use, we suggest adequate concentrations of antimicrobials with adequate antibacterial efficacy should be used.

A comparative evaluation of cyclic fatigue resistance for different endodontic NiTi rotary files: An in-vitro study.

AIM: This in-vitro study evaluated and compared the flexural fatigue resistance for Hero Shapers, Hyflex CM, One Shape, Profile Vortex and Protaper Next rotary NiTi files. METHOD AND MATERIALS: Total 25 rotary NiTi files allocated to each experimental group were tested in a simulated constructed apparatus with an angle of curvature 60° & radius of curvature 5 mm. Each experimental file was coated with EDTA gel and was placed in endodomotor handpiece with rubber stopper at support steel cylinder and its end between two shaping steel cylinders on the simulated apparatus. File was then rotated at 400 rpm, 2.5 N/cm torque and simultaneously digital stop watch was started. Time taken (in seconds) until the file got fractured was recorded. RESULTS: Time taken to fracture ranged from 7 to 58 s in different groups. Analysis of variance show a statistically significant intergroup difference (p < 0.001). Tukey HSD test showed the significant differences. The Weibull modulus values ranged from 7.31 to 24.19. CONCLUSION: Cyclic flexural fatigue resistance was observed highest for Grp IV (Hyflex CM) and lowest for Grp I (Hero Shapers). CLINICAL SIGNIFICANCE: Hyflex CM rotary NiTi files can be used in curved root canals as they had superior resistance and long survival time which will be helpful in eliminating one of the reasons for file fracture (due to cyclic flexural fatigue) during the root canal treatment clinically where root canal possesses a sharp bend or curve.

Comparative antimicrobial efficacy of selected root canal irrigants on commonly isolated microorganisms in endodontic infection.

OBJECTIVE: This study aims to evaluate and compare the antimicrobial efficacy of three selected root canal irrigants (BioPure MTAD, metronidazole, aztreonam) against microbes commonly isolated from polymicrobial microbiota of root canal infection. MATERIALS AND METHODS: This study was designed with four experimental groups (Group I - Bacteroides fragilis, Group II - Propionibacterium acnes, Group III - Enterococcus faecalis, Group IV - Candida albicans) based on the microbes selected for the study. Group I and Group II bacteria were used to compare and evaluate antimicrobial effect of BioPure MTAD, metronidazole, aztreonam, and normal saline. Group III and Group IV bacteria were used to compare and evaluate antimicrobial efficacy of BioPure MTAD, aztreonam, and normal saline. Normal saline was used as a control irrigant in this study. Agar disc diffusion method was applied to assess and compare the antimicrobial action of selected irrigants. RESULTS: Metronidazole was found to be the most effective root canal irrigant against B. fragilis and P. acnes among the tested irrigants. Mean zone of inhibition against E. faecalis has been shown to be maximum by BioPure MTAD, followed by aztreonam. Antifungal effect against C. albicans was only shown by BioPure MTAD. CONCLUSIONS: Overall, BioPure MTAD is the most effective root canal irrigant as it has shown an antibacterial effect against all the tested microorganisms. However, metronidazole showed maximum antibacterial effect against obligate anaerobes. Aztreonam also showed an antibacterial effect in the present study, raising its possibility to be used as a root canal irrigant in the future.

Comparative Evaluation of Electronic Apex Locators and Radiovisiography for Working Length Determination in Primary Teeth in vivo.

AIMS: The aim of this study was to evaluate the effectiveness of two different varieties of electronic apex locators and radiovisiography (RVG) for working length determination in primary teeth. MATERIALS AND METHODS: A total of 30 primary teeth indicated for pulpectomy in children aged 3 to 8 years were randomly selected and subjected to working length determination using two varieties of electronic apex locators and RVG separately. The data were then subjected to statistical analysis. RESULTS: A very strong correlation between electronic measurement methods and RVG length was observed. CONCLUSION: Radiovisiography and apex locators are equally effective in determining working length in primary teeth. How to cite this article: Abdullah A, Singh N, Rathore MS, Tandon S, Rajkumar B. Comparative Evaluation of Electronic Apex Locators and Radiovisiography for Working Length Determination in Primary Teeth in vivo. Int J Clin Pediatr Dent 2016;9(2):118-123.

Fibrates inhibit aldose reductase activity in the forward and reverse reactions.

Fibrates such as bezafibrate, gemfibrozil, clofibric acid, ciprofibrate and fenofibrate, are ligands for peroxisome proliferator-activated receptor alpha (PPARalpha), and are used as therapeutic agents in the treatment of hyperlipidemia. Synthesis and accumulation of sorbitol in cells due to aldose reductase (AR) activity is implicated in secondary diabetic complications. In pursuit of finding a lead compound identification to design an effective AR inhibitor employing fragment-based design-like approach, we found that this class of compounds and their nearest neighbors could inhibit AR. Bezafibrate and gemfibrozil displayed a mixed non-competitive inhibition pattern in the glyceraldehyde reduction activity and pure non-competitive inhibition pattern in the benzyl alcohol oxidation activity of AR. Clofibric acid, ciprofibrate and fenofibrate showed pure non-competitive inhibition patterns in the forward reaction. In the reverse reaction, clofibric acid displayed a non-competitive inhibition pattern while ciprofibrate and fenofibrate displayed competitive inhibition patterns. This finding reveals for the first time a novel attribute of the fibrates in the regulation of AR activity and may be useful as lead compounds to control the function of AR in the progression and treatment of secondary diabetic complications in addition to other clinical conditions. Alternatively, these findings demonstrate that AR plays a significant role in the fibrate metabolism under various scenarios.

Comparative evaluation of shear bond strength of three resin based dual-cure core build-up materials: An In-vitro study.

AIM: The in-vitro study compared the shear bond strength (SBS) of three recently introduced dual-cure resin based core build-up materials namely ParaCore, FluoroCore, and MultiCore. MATERIALS AND METHODS: One hundred twenty extracted permanent human mandibular molar teeth were taken and sectioned horizontally beneath the dentinoenamel junction to expose the coronal dentin. The specimens obtained were divided into three main groups based on the materials used and then further divided into four sub-groups based on time interval with ten samples each. The dentin surface was treated with the respective adhesives of the groups and then bulk filled with core build-up materials. The attained samples were than subjected to shear loading in Instron Universal Testing Machine. The data were tabulated and statistically analyzed using analysis of variance (ANOVA), Tukey's HSD, and Levene's test. RESULTS: The mean SBS was highest in MultiCore at all time periods as compared to FluoroCore and ParaCore and was also higher at 48 h thermocycling in all three groups studied. CONCLUSION: MultiCore dual-cure resin based core build-up material showed the highest mean SBS as compared to FluoroCore and ParaCore. SBS was not negatively affected by thermocycling.

In Vivo Evaluation of Two-Piece Implants Placed Following One-Stage and Two-Stage Surgical Protocol in Posterior Mandibular Region. Assessment of Alterations in Crestal Bone Level.

BACKGROUND: Endosseous implants can be placed following either two-stage technique requiring second-stage surgery or one-stage technique, which does not involve a second surgical intervention. PURPOSE: The present study was undertaken to evaluate and compare the changes in crestal bone level when two-piece implants were placed in posterior mandibular region following one-stage and two-stage surgical protocol. MATERIALS AND METHODS: A parallel group randomized prospective study was designed in which 20 two-piece implants were placed in the posterior mandibular region of 16 partially edentulous healthy patients following either one-stage (Group I) or a two-stage surgical protocol (Group II). Alterations in crestal bone level were assessed with the help of DentaScan at baseline, that is, at the time of implant placement, third month and sixth month. RESULTS: Nonsignificant differences were seen in both groups in terms of changes in crestal bone level at the final evaluation. CONCLUSIONS: Hence, it could be concluded that two-piece implants can be placed following one-stage surgical protocol as predictably as when two-stage surgical technique is followed.

WY 14,643 inhibits human aldose reductase activity.

Aldose reductase (AR) is implicated to play a critical role in diabetes and cardiovascular complications because of the reaction it catalyzes. Our data reveal that peroxisome proliferator WY 14,643, follows a pure non-competitive inhibition pattern in the aldehyde reduction activity as well as in the alcohol oxidation activity of AR. This finding communicates for the first time a novel feature of WY 14,643 in regulating AR activity. In addition, this observation indicates that AR, AR-like proteins and aldo-keto reductase (AKR) members may be involved in the WY 14,643 mechanism of action when it is administered as PPAR agonist.