Comparative evaluation of different instrument kinematics on contact percentage, dentin removal and apical debris extrusion in oval canals.

The aim of this study was to compare four different instrument kinematics in oval canals. Distal root of sixty extracted first mandibular molars with single oval canal were allocated randomly to four groups (n = 15) namely protaper universal [PTU] (Rotary), self-adjusting file [SAF] (Adaptive), TruShape [TS] (Rotary) and WaveOne [WO] (Reciprocating). The percentage of untouched and touched surfaces of the root canal was evaluated using micro-computed tomography (MCT). Pre- and post-instrumentation weight was assessed using digital microbalance for determining the amount of dentin removed and apical extrusion of debris. The results were tabulated, and their mean difference was statistically analysed using one-way ANOVA and Tukey's HSD test. PTU and SAF exhibited significantly less mean percentage of untouched surface compared to TS. TS files removed less dentin and extruded less debris in long oval canals.

Calcium hydroxide and niobium pentoxide treatment effects before MTA placement.

The aim of this study was to evaluate the effect of calcium hydroxide (CH) and niobium pentoxide (NP) pretreatment on pH, dentin microhardness and sealing of Mineral Trioxide Aggregate (MTA; Angelus). The pH of CH, NP and CH-NP (3:1) was evaluated in neutral and acidic simulated tissue fluid over 28 days. The Vickers microhardness was measured in forty 4 mm coronal root slices filled with pretreatment materials stored in medium for 1, 7, 28 days. Forty 10 mm roots were packed with pretreatment materials, irrigated after 24 h, then a 3 mm MTA plug was placed. Sealing ability was evaluated after 7 days using fluid filtration method. Statistics was performed using ANOVA and post hoc Tukey HSD tests. Addition of NP to CH maintained the alkalinity of CH, increased the microhardness of root dentin and reduced the microleakage. CH-NP can be effectively used as a pretreatment medicament in root canals requiring placement of MTA under acidic conditions.

Current trend of restoration of endodontically treated teeth with extensive subgingival caries: A case series.

Endodontically treated teeth (ETT) are structurally and esthetically compromised. Conventionally, after endodontic therapy, the tooth is restored with full-coverage crowns to improve their fracture resistance and ensure their long-term success rate. However, the tooth preparation required for these restorations can result in the significant loss of enamel and dentin. The periodontal health will be affected if the margin of prosthesis is extended subgingival. Restoring ETT using minimally invasive methods is an effective way to preserve the remaining tooth structure. This case series show cases restoration of four endodontically treated mandibular first molars with extensive subgingival caries restored with short fiber-reinforced composite resin (everX Posterior, GC Europe N.V. Interleuvenlaan, Leuven), with 2-year follow-up.

Demystifying Dens Invaginatus: Suggested Modification of the Classification based on a Comprehensive Case Series.

Dens invaginatus (DI) is one of the most common developmental anomalies observed in maxillary lateral incisors. An early diagnosis requires thorough clinical knowledge, advanced radiographic evaluation as well as the use of cone beam computed tomography (CBCT) and dental operating microscope (DOM), dictates the successful endodontic management of such teeth. A total of 7 cases with (DI) in maxillary lateral incisors were collected from dental practitioners worldwide, analysed and reported in the present case series. Our aim was to analyse and understand the various morphological patterns of DI in maxillary lateral incisors with their varied treatment protocols employed worldwide. This article illustrates the aberrant morphological patterns and the diverse treatment protocols followed by the clinicians worldwide. The use of biomaterials enhances post-operative healing. Further, a modification in the existing classification has been proposed in this report which would enable the clinicians to easily diagnose, categorise and effectively manage DI. The different treatment protocols employed for the management of DI has been discussed and the use of CBCT and DOM in identifying and managing the anatomical variation of DI were emphasised.

Anti-inflammatory efficacy of petasin-incorporated zinc oxide eugenol sealer - An in vivo zebrafish study.

Background: The eugenol from zinc oxide eugenol (ZnOE) sealer tends to diffuse to the periapical region resulting in inflammation. Several modifications of ZnOE sealer have been formulated to minimize the inflammatory potential of the ZnOE sealer. Petasites hybridus contains petasin which possesses anti-inflammatory property used in treatment of migraine and allergic rhinitis. Aim: The aim of the study was to evaluate the anti-inflammatory property of petasin-incorporated ZnOE sealer on zebrafish. Materials and Methods: The study has been reviewed and approved by the Institutional Review Board (SRMU/MandHS/SRMDC/2018/S/025) and by the in-house Institutional Animal Ethics Committee (IAEC) of Pentagrit Research Lab and conducted with compliance to ICH harmonization and principles for animal housing and handling (IAEC Study No: 215/Go06/IAEC). The samples were implanted in the caudal portion of the zebrafish. The samples (n = 50) were divided into five groups (n = 10) - Group 1: incision only (negative control), Group 2: zinc oxide (ZnO) (positive control), Group 3: ZnO + eugenol and petasin in ratio of 10:1, Group 4: ZnO + eugenol and petasin in ratio of 5:1, and Group 5: ZnO + eugenol and petasin in ratio of 1:1. The experimental groups were further subdivided into two subgroups based on time intervals at 24 h and 48 h. The tissue samples were assessed using smear pathology test, and the percentage of inflammation was evaluated. The data were statistically analyzed using SPSS software version 22.0 with a significance level fixed as 5% (α = 0.05). Results: The presence of inflammatory cells and congestion of arterioles were taken as the criteria to assess inflammatory action. It was maximum in ZnOE sealer followed by ZnOE sealer modified with the addition of petasin to eugenol in the ratio of 10:1, 5:1, and 1:1, respectively. Conclusion: The addition of petasin extract to ZnOE reduces the inflammation potential of ZnOE sealers. ZnOE sealer containing eugenol and petasin in the ratio of 1:1 showed a maximal reduction in inflammation.

Antibacterial evaluation of guava leaves extract and its effect on reactive oxygen species formed by calcium hydroxide and chlorhexidine mixture.

Background: Reactive oxygen species (ROS) are formed when mixing calcium hydroxide (CH) with chlorhexidine (CHX). Aim: To analyze the antibacterial efficacy of aqueous (AGL) and ethanolic (EGL) extracts of Psidium guajava leaves against root canal bacteria such as Streptococcus mutans, Staphylococcus aureus, Lactobacillus acidophilus and Enterococcus faecalis, to evaluate the antioxidant potential of the extracts and its ability to counteract the ROS. Materials and Methods: Three different concentrations (10%, 25%, and 35%) of AGL and EGL were prepared. The antibacterial efficacy was analyzed using the Kirby-Bauer disc diffusion method. The different concentrations of both AGL and EGL were evaluated for their antioxidant property using ultraviolet spectrometer. Further, the ability of these extracts on neutralizing the ROS formation was analyzed using mass spectrometer. Results: CH and CHX mixture exhibited maximum antibacterial activity followed by the same mixture with 35% EGL. EGL showed greater antioxidant activity than AGL extract at all concentrations. Conclusions: The addition of natural antioxidants like guava leaves extract decreases ROS formed by CH and CHX mixture.

A novel petasin-modified zinc oxide eugenol sealer.

OBJECTIVE: Zinc oxide eugenol (ZOE) is one of the most commonly used root canal sealer. However, it has few drawbacks such as cytotoxicity, solubility, and irritation to periapical tissues. The scope of this study was to investigate the setting time, solubility, cytotoxic effects, and anti-inflammatory action of ZOE sealer with the modification of its liquid component by the addition of petasin extract in the ratios 1:1, 5:1, and 10:1. MATERIALS AND METHODS: Setting time was evaluated using the Vicat's apparatus. For testing solubility, the American Dental Association's specification #8 was adopted with certain modifications. Protein denaturation assay and 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazoliumbromide assay with L929 mouse fibroblast cell lines were used to evaluate the anti-inflammatory property and cytotoxicity, respectively. RESULTS: ZOE sealer with petasin extract in the ratio of 5:1 showed the least initial and the final setting times. There was no statistically significant difference in the amount of solubility for all the groups at the various time intervals. The cytotoxicity of the control group was significantly greater than all the experimental groups, whereas the anti-inflammatory effect of the former was statistically lower. CONCLUSIONS: The combination of ZOE with petasin extract in the ratio of 5:1 showed lower setting time, cytotoxicity, and better anti-inflammatory property.

Maxillary Second Molar with Fused Root and Six Canals- A Case Report.

One of the known aberrations in root canal morphology of maxillary second permanent molars is the presence of collateral mesiobuccal canals. This case report describes the endodontic management of a maxillary second molar that had a single fused root with six canals that was successfully managed with the aid of dental operating microscope. Six canal orifices were located namely MB1 (Mesiobuccal), MB2, MB3, DB1 (Distobuccal), DB2 and palatal. During the cleaning and shaping, instrument separation occurred at the apical third of the palatal canal which was removed with ultrasonics. After cleaning and shaping, the canals were obturated with resin sealer and laterally condensed gutta-percha. The patient was recalled for periodic review. After two years of follow up the patient remained asymptomatic. Cone Beam Computed Tomography (CBCT) evaluation revealed satisfactory periapical status.

Effect of bleaching with two different concentrations of hydrogen peroxide containing sweet potato extract as an additive on human enamel: An in vitro spectrophotometric and scanning electron microscopy analysis.

OBJECTIVES: To evaluate the color change in teeth bleached with two different concentrations of hydrogen peroxide, containing sweet potato extract as an additive, using a spectrophotometer, and to evaluate the surface changes in enamel using a scanning electron microscope (SEM). MATERIALS AND METHODS: Baseline color values of 24 artificially stained incisors were obtained using a spectrophotometer. The specimens were divided into two groups of 12 teeth, each based on the concentration of hydrogen peroxide (H(2)O(2)) as follows: Group I - 35% H(2)O(2) and Group II - 10% H(2)O(2). One-half of the tooth was bleached with H(2)O(2) alone (Subgroup A) and the other half was bleached with a combination of H(2)O(2) and sweet potato extract (Subgroup B). Post bleaching the Commission Internationale de l' Eclairage L(*), a(*), b(*) (CIEL(*)a(*)b(*)) values were obtained and ΔE was calculated. The surfaces of the samples were examined using SEM. RESULTS: The mean ΔE values of groups IB (72.52 ± 2.03) and IIB (71.50 ± 1.81) were significantly higher than those of groups IA (65.24 ± 1.02) and IIA (64.19 ± 1.88), respectively, (P < 0.05). The SEM images of groups IB and IIB showed lesser surface irregularities and morphological alterations in enamel. CONCLUSION: The addition of sweet potato extract to hydrogen peroxide not only resulted in the restoration of the natural tooth color, but also decreased the effects of bleaching on the enamel morphology, compared to the use of hydrogen peroxide alone.

New nomenclature for extra canals based on four reported cases of maxillary first molars with six canals.

This clinical article describes 4 different case reports of maxillary first molars with unusual anatomy of 6 root canals and their endodontic management. Treating these additional canals in maxillary first molars might be challenging. Inability to locate and properly treat these extra canals might lead to failures. A thorough knowledge of root canal morphology and the proper use of microscopes increase chances for successful clinical results. Because presence of these extra canals is not unusual and naming these canals still remains elusive, a new nomenclature is suggested for ease of communication.