Influence of Access Cavity Design on the Fracture Strength of Endodontically Treated Teeth Restored Using Short Fiber-Reinforced Composite and High Strength Posterior Glass Ionomer Cement.

AIM: This in vitro study aimed to determine the influence of access cavity design and residual tooth structure and to compare the fracture resistance of the teeth post endodontically restored with short fiber-reinforced composite (GC everX Posterior; GC, India) and conventional posterior high-strength GIC (Glass Ionomer Cement) (GC Gold Label IX; GC, India). METHODS: Ninety extracted human mandibular molars were classified into five groups, i.e., one control group (n = 10) and four test groups based on the access cavity design (n = 20): Traditional access cavity (TAC), Conservative access cavity (CAC), Ninja access cavity (NAC), and Truss access cavity (TRAC). Then 80 teeth in test groups were endodontically treated and further subdivided (n = 10) based on post-endodontic restorative materials, i.e., short fiber-reinforced composite (SFC) and Type 9 GIC. Samples were then subjected to fracture resistance under a universal testing machine and fracture loads were compared statistically. RESULTS: The fracture resistance of various access cavity designs (TAC, CAC, NAC, and TRAC) varied significantly (P < .05). Regardless of access cavity design, teeth restored with SFC had higher fracture resistance than teeth restored with high strength posterior GIC (P = .001). CONCLUSION: Using newer access cavity designs like (CAC, NAC, and TRAC) and reinforcing the teeth with a post-endodontic restoration such as SFC, fracture resistance of endodontically treated teeth can be improved notably.

Position Statement of IACDE for managing dental patients during COVID-19.

Coronavirus disease 2019 (COVID-19) has been a major health concern globally ever since it was declared as Pandemic by the World Health Organization in March 2020. Due to the evolving and contagious nature of coronavirus, it continues to remain a threat for dental health-care personnel. As the virus travels from person-to-person via direct contact through droplet inhalation, cough, and sneeze or through contact transmission, it remains infectious even through inanimate surfaces. A seemingly healthy asymptomatic person may have the potential to trigger the spread of this disease. Coronavirus has the capability of spreading through community transmission. There is no specific treatment or vaccine as of now for stopping the spread of COVID-19, hence universal precautions and awareness with mass involvement is required to ward off this pandemic. Dental health-care personnel are at immense risk due to the near proximity with patients and continual exposure to saliva, blood, and other body fluids. Management protocol regarding awareness and preventive measures should be laid down for dental clinic/hospital to contain the outspread of this infectious disease.

Extensive external localized idiopathic root resorption - An unusual case report.

External root resorption of permanent teeth is a multifactorial process. This article presents an unusual case of localized idiopathic extensive external root resorption involving the whole mesial root of the right mandibular first molar in a 42-year-old female patient. No significant systemic, dental, or familial findings could be identified as a possible cause. The cause of the resorption remained unclear. The tooth was managed by nonsurgical endodontic treatment using mineral trioxide aggregate to seal resorbed canals. A 5-year follow-up revealed satisfactory results clinically and radiographically with mobility within physiological limits.

Incremental techniques in direct composite restoration.

Polymerization shrinkage is one of the dental clinician's main entanglements when placing resin-based composite restorations. None of the method can assure a perfectly sealed restoration for adhesive restorative materials; clinicians must abode problems of polymerization shrinkage and its possible ill effects. The objective of this article is to review different incremental techniques that can ruin the polymerization shrinkage stress of direct composite restoration.

Comparative evaluation of antimicrobial efficacy of QMix™ 2 in 1, sodium hypochlorite, and chlorhexidine against Enterococcus faecalis and Candida albicans.

AIM/OBJECTIVE: The aim of this study is to compare the antimicrobial efficacy of QMix™ 2 in 1, sodium hypochlorite (NaOCl), and chlorhexidine (CHX) against Enterococcus faecalis and Candida albicans. MATERIALS AND METHODS: Eighty freshly extracted, single-rooted human mandibular premolar teeth were instrumented and autoclaved. Samples were divided into two groups of 40 teeth each based on the type of microorganism used. Group I was inoculated with E. faecalis and Group II with C. albicans and incubated for 3 days. Each group was subdivided into four subgroups based on the type of irrigant used. Group IA, IIA, 5.25% NaOCl; Group IB, IIB, 2% CHX; Group IC, IIC, QMix™ 2 in 1; and Group ID, IID, 0.9% saline (the control group). Ten microliters of the sample from each canal was taken and was placed on Brain Heart Infusion agar and Sabouraud dextrose agar. The plates were incubated at 37°C for 24 h and colony forming units (CFUs) that were grown were counted. Data was analyzed with analysis of variance (ANOVA) followed by post-hoc Games-Howell test. RESULTS: The greatest antimicrobial effects were observed in samples treated with QMix™ 2 in 1 (P < 0.001). No statistical significant difference was found between 5.25% NaOCl and 2% CHX (P > 0.001) against E. faecalis and C. albicans. CONCLUSION: QMix™ 2 in 1 demonstrated significant antimicrobial efficacy against E. faecalis and C. albicans.

"Dentinal microcracks after root canal preparation" a comparative evaluation with hand, rotary and reciprocating instrumentation.

INTRODUCTION: The purpose of this study was to compare the incidence of dentinal micro cracks after instrumentation with various types of NiTi files in rotary and reciprocating motion. MATERIALS AND METHODS: One hundred human extracted mandibular central incisors were taken and divided into 10 groups (n=10 teeth per group). Group 1- No preparation, Group 2 - Hand instrumentation, Groups 3,4 - ProTaper files in rotary and reciprocating motion, Groups 5,6 - ProTaper Next files in rotary and reciprocating motion, Groups 7,8 - Oneshape files in rotary and reciprocating motion, Groups 9,10 - Reciproc files in rotary and reciprocating motion. Specimens were sectioned horizontally at 3,6 and 9 mm from the apex and dentinal micro cracks were observed under a stereomicroscope. RESULTS: There was a statistically significant difference between the groups (p<0.05). There were no significant differences in crack formation between the groups (Protaper Next - Rot, Protaper Next - Rec, Reciproc - Rec); (ProTaper - Rot, ProTaper - Rec, Oneshape - Rot), (Oneshape - Rot, Reciproc - Rot), (One shape Reciproc, Reciproc - Rec); (p >.05). CONCLUSION: Least cracks were seen in canals instrumented with Pro Taper Next files both in rotary and reciprocating motion. Full sequence rotary systems showed less cracks than single file systems and full sequence rotary systems showed less cracks in reciprocating motion than in rotary motion.

Evaluation of biocompatibility of a new root canal irrigant Q Mix™ 2 in 1- An in vivo study.

AIM: To evaluate the biocompatibility of a new root canal irrigant Q mix™ 2 in 1 in comparison to 0.9% sterile saline, 3% sodium hypochlorite (NaOCl), 2% chlorhexidine (CHX), and 17% ethylenediaminetetraacetic acid (EDTA). MATERIALS AND METHODS: Six circles were drawn on the dorsal skin of 24 male Wistar Albino rats, leaving 2cm between each circle. Using a syringe, 0.1mL of each root canal irrigant was injected subcutaneously into five circles. In the sixth circle, the needle of an empty syringe was introduced into the skin, but no irrigant was injected (control group). Evaluations were done at 2 hours, 48 hours, 14 days, and 30 days postprocedure. Tissue samples were excised, embedded in paraffin blocks, and 3 µm thick sections were obtained and stained with hematoxylin and eosin. The areas of inflammatory reaction were evaluated. From each tissue sample, five sections presenting the greatest inflammatory reactions were examined under a light microscope, and analyzed statistically by analysis of variance (ANOVA) and Tukey's test. RESULTS: At the two-hour examination period, all the irrigants showed a slight increase in the number of inflammatory cells, at 48 hours, the number of inflammatory cells were increased significantly, and after 14 and 30 days, they were decreased gradually. Qmix™ 2 in 1 showed a smaller number of inflammatory cells than other irrigants tested. CONCLUSION: QMix™ 2 in 1 was shown to be less toxic to the rat subcutaneous tissue than 3% NaOCl, 2% CHX, and 17% EDTA.

Assessment of the wetting behavior of three different root canal sealers on root canal dentin.

AIM: The objective of the present study was to evaluate and compare the wetting behavior of three different root canal sealers on the root canal dentin surface treated with irrigants and their combination. MATERIALS AND METHODS: Decoronation and apical third resections of 27 extracted single-rooted human mandibular premolars were done. The roots were then split longitudinally into two halves, and randomly assigned into three treatment groups (n=18). The root dentin surfaces in Group1, Group 2 and Group 3 were treated with 17% ethylene diamine tetra acetic acid (EDTA), 3% sodium hypochlorite (NaOCl) and combination of 17% EDTA and 3% NaOCl, respectively. Each group was subdivided into three subgroups of 6 specimens each, depending on the the sealer used, i.e. sub group A. zinc oxide (ZnOE), sub group B. AH plus, subgroup C. Guttaflow sealer, respectively. The contact angle was measured using First Ten Angstroms (FTA) 200 dynamic contact angle analyzer. RESULTS: The contact angle values for AH Plus sealer were significantly lower when compared to the other two sealer groups. CONCLUSION: The wettability of AH Plus sealer on the root surface dentin was found to be better than Gutta-Flow and ZnOE sealer.

Expansion of gutta-percha in contact with various concentrations of zinc oxide-eugenol sealer: a three-dimensional volumetric study.

INTRODUCTION: Successful endodontic treatment depends on achievement of a fluid-tight seal that is not possible solely with gutta-percha and requires the use of a root canal sealer. Eugenol, which is a principal component in zinc oxide-eugenol (ZOE) based sealers, is reported to produce a volumetric expansion of gutta-percha. The aim of this study was to evaluate the three-dimensional expansion of gutta-percha at various powder/liquid ratios of ZOE-based sealer by using spiral computed tomography (SCT). METHODS: Fifty freshly extracted premolars with single canal were decoronated and instrumented by using RaCe rotary instruments (35/06). The teeth were divided into 5 groups of 10 each, and volume of the canal was measured by using SCT. The teeth were then obturated with gutta-percha cones (35/04) in groups ZE 1:1 to ZE 1:4 with Pulp Canal Sealer EWT (ZOE-based) with powder/liquid ratio of 1:1, 1:2, 1:3, and 1:4, respectively, and gutta-percha alone in control group (no sealer group). The filled volume in each canal was measured by using SCT 1 day, 7 days, and 1 month after obturation, and percentages of obturated volume and of volume changes in groups over time were calculated. The data were statistically analyzed by using one-way analysis of variance and post hoc multiple comparison tests. RESULTS: The groups ZE 1:2 and ZE 1:3 gave the highest mean volume values during a 1-month period and were significantly different in comparison with groups ZE 1:1 and ZE 1:4 (P < .05). CONCLUSIONS: Increasing the ratio of eugenol in sealer resulted in volumetric increase of gutta-percha. However, further studies should be performed to confirm the expansion and sealing ability of gutta-percha of the size corresponding to the prepared canal, leading to the achievement of fluid impervious seal.

Spectrophotometric and colorimetric evaluation of staining of the light cured composite after exposure with different intensities of light curing units.

AIM/OBJECTIVE: To understand the importance of intensity of light in polymerizing light cured composites and its relation to color stability. MATERIALS AND METHODS: Forty specimens of composite disc with 3mm diameter and 1.5 mm thick were divided into two groups of 20 samples each. Group1: Twenty samples were cured with a light curing unit of380mw/cm(2). Group2: Twenty samples cured with a light curing unit of 680mw/cm(2). These polymerized samples were immersed in methylene blue dye for 24hoursand later washed and immersed in absolute alcohol for 24 hours. The amount of color released into absolute alcohol was assessed by spectrophotometric and colorimetric analysis. RESULTS: Results were analyzed for spectrophotometric and colorimetric values by using the Mann-Whitney test. The group cured with low intensity light stained more compared to the group cured with a normal intensity of light. CONCLUSIONS: Intensity of light plays a crucial role in staining of the polymerized light cured composite. The intensity of the curing unit has to be maintained in acceptable limits to achieve good clinical results.