An in vitro study of a novel quaternary ammonium silane endodontic irrigant.

OBJECTIVE: To analyze effect of NaOCl+2% quaternary ammonium silane (QAS)-containing novel irrigant against bacteria impregnated inside the root canal system, and to evaluate its antimicrobial and mechanical potential of dentine substrate. METHODS: Root canal was prepared using stainless steel K-files™ and ProTaper™ and subjected to manual and ultrasonic irrigation using 6% NaOCl+2% CHX, 6% NaOCl+2% QAS and saline as control. For confocal-microscopy, Raman spectroscopy and SEM analysis before and after treatment, Enterococcus faecalis cultured for 7 days. Raman spectroscopy analysis was done across cut section of gutta percha/sealer-dentine to detect resin infiltration. Indentation of mechanical properties was evaluated using a Berkovich indenter. The contact angle of irrigants and surface free energy were evaluated. Mineralization nodules were detected through Alazarin red after 14 days. RESULTS: Control biofilms showed dense green colonies. Majority of E. faecalis bacteria were present in biofilm fluoresced red in NaOCl+2% QAS group. There was reduction of 484cm-1 Raman band and its intensity reached lowest with NaOCl+2% QAS. There was an increase in 1350-1420cm-1 intensity in the NaOCl+2% CHX groups. Gradual decrease in 1639cm-1 and 1609cm-1 Raman signal ratios were seen in the resin-depth region of 17µm>, 14.1µm> and 13.2µm for NaOCl+2% QAS, NaOCl+2% CHX and control groups respectively. All obturated groups showed an intact sealer/dentine interface with a few notable differences. 0.771 and 83.5% creep indentation distance for NaOCl+2% QAS ultrasonic groups were observed. Highest proportion of polar component was significantly found in the NaOCl+2% QAS groups which was significantly higher as compared to other groups. Mineralized nodules were increased in NaOCl+2% QAS. SIGNIFICANCE: Favorable antimicrobial and endodontic profile of the NaOCl+2% QAS solution might suggest clinical use for it for more predictable reduction of intracanal bacteria.

Clinical audit training improves undergraduates' performance in root canal therapy.

AIM: To evaluate the effectiveness of clinical audit-feedback cycle as an educational tool in improving the technical quality of root canal therapy (RCT) and compliance with record keeping performed by dental undergraduates. METHODS: Clinical audit learning was introduced in Year 3 of a 5-year curriculum for dental undergraduates. During classroom activities, students were briefed on clinical audit, selected their audit topics in groups of 5 or 6 students, and prepared and presented their audit protocols. One chosen topic was RCT, in which 3 different cohorts of Year 3 students conducted retrospective audits of patients' records in 2012, 2014 and 2015 for their compliance with recommended record keeping criteria and their performance in RCT. Students were trained by and calibrated against an endodontist (κ ≥ 0.8). After each audit, the findings were reported in class, and recommendations were made for improvement in performance of RCT and record keeping. Students' compliance with published guidelines was presented and their RCT performances in each year were compared using the chi-square test. RESULTS: Overall compliance with of record keeping guidelines was 44.1% in 2012, 79.6% in 2014 and 94.6% in 2015 (P = .001). In the 2012 audit, acceptable extension, condensation and the absence of mishap were observed in 72.4, 75.7% and 91.5%; in the 2014 audit, 95.1%, 64.8% and 51.4%; and in 2015 audit, 96.4%, 82.1% and 92.8% of cases, respectively. In 2015, 76.8% of root canal fillings met all 3 technical quality criteria when compared to 48.6% in 2014 and 44.7% in 2012 (P = .001). CONCLUSION: Clinical audit-feedback cycle is an effective educational tool for improving dental undergraduates' compliance with record keeping and performance in the technical quality of RCT.

Comparative evaluation of the effectiveness of desensitizing agents in dentine tubule occlusion using scanning electron microscopy.

BACKGROUND: Dentine hypersensitivity (DH) occurs on exposed dentine and is dependent on the patency of dentinal tubules. This study compared the effectiveness of red propolis extract (RPE), calcium sodium phosphosilicate (Novamin) and arginine-calcium carbonate (ACC) in occluding dentine tubules. METHODS: Eighty dentine discs from extracted human molars were randomly divided into four groups (n=20): Group 1--RPE; Group 2--Novamin; Group 3--ACC; Group 4--saline. The discs were etched with 37.5% phosphoric acid and treated with the test agents. Ten treated discs from each group were then exposed to 6% citric acid challenge. The extent of tubule occlusion was assessed using scanning electron microscopy (SEM). Three blinded assessors scored each SEM image on the degree of tubule occlusion. Differences in occlusion were tested using ANOVA and Tukey adjustment. RESULTS: Discs treated with ACC demonstrated more tubule occlusion, followed by RPE and Novamin, and were greater in statistical significance when compared to discs treated with saline. Following acid challenge, RPE treated discs maintained more occlusion, followed by ACC and Novamin. CONCLUSIONS: All three agents demonstrated tubule occlusion. Although ACC showed more occlusion following treatment, RPE demonstrated a higher degree of occlusion following acid challenge.

Genotranscriptomic meta-analysis of the Polycomb gene CBX2 in human cancers: initial evidence of an oncogenic role.

BACKGROUND: Polycomb group (PcG) proteins are histone modifiers known to transcriptionally silence key tumour suppressor genes in multiple human cancers. The chromobox proteins (CBX2, 4, 6, 7, and 8) are critical components of PcG-mediated repression. Four of them have been associated with tumour biology, but the role of CBX2 in cancer remains largely uncharacterised. METHODS: Addressing this issue, we conducted a comprehensive and unbiased genotranscriptomic meta-analysis of CBX2 in human cancers using the COSMIC and Oncomine databases. RESULTS: We discovered changes in gene expression that are suggestive of a widespread oncogenic role for CBX2. Our genetic analysis of 8013 tumours spanning 29 tissue types revealed no inactivating chromosomal aberrations and only 40 point mutations at the CBX2 locus. In contrast, the overall rate of CBX2 amplification averaged 10% in all combined neoplasms but exceeded 30% in ovarian, breast, and lung tumours. In addition, transcriptomic analyses revealed a strong tendency for increased CBX2 mRNA levels in many cancers compared with normal tissues, independently of CDKN2A/B silencing. Furthermore, CBX2 upregulation and amplification significantly correlated with metastatic progression and lower overall survival in many cancer types, particularly those of the breast. CONCLUSIONS: Overall, we report that the molecular profile of CBX2 is suggestive of an oncogenic role. As CBX2 has never been studied in human neoplasms, our results provide the rationale to further investigate the function of CBX2 in the context of cancer cells.

A comparative effect of mouthwashes with different alcohol concentrations on surface hardness, sorption and solubility of composite resins.

UNLABELLED: The longevity and durability of composite resins are influenced by the actions of water, saliva, drinks, food and features of the oral environment. OBJECTIVE: The aim of this study was to evaluate the effect of mouthwashes containing alcohol on the surface hardness, sorption and solubility of composite resins. METHODS: Disc-shaped specimens were prepared with two composite resins Z250 (Z2) and Z350XT (Z3). Measurements of Vickers hardness were performed before and after immersion in Plax, PerioGard, Listerine, ethanol and distilled water for 12 h at 37°C, followed by a further 12 h at 37°C in artificial saliva. Sorption and solubility were performed according to ISO 4049. Data were analysed using one-way ANOVA and Tukey tests (α=0.05). RESULTS: None of the mouthwashes significantly reduced the hardness of the resin Z2 (p>0.05). The greatest change in resin Z3 hardness was produced by PerioGard (p<0.01). Plax produced the lowest changes in the sorption and solubility of resins Z2 and Z3 (p<0.01), followed by Listerine and PerioGard. CONCLUSIONS: The sorption and solubility properties of the composite resins were more altered by mouthwashes than the surface hardness.

Asthma and oral health: a review.

Asthma is a chronic inflammatory condition that causes the airways to constrict and produce excess mucus, making breathing difficult. It is characterized by the obstruction of airflow which is variable over a short period of time. This condition is reversible, either spontaneously or can be controlled with the help of drugs. Asthma medication comprises bronchodilators, corticosteroids and anticholinergic drugs. Most of these drugs are inhaled using various forms of inhalers or nebulizers. The effect of these drugs on oral health is the subject of debate among dental practitioners. Patients taking asthma medication may be at risk of dental caries, dental erosion, periodontal diseases and oral candidiasis. Hence, patients with bronchial asthma on medication should receive special prophylactic attention. This article reviews the correlation between asthma and oral health, and suggests various measures to counter possible oral health problems related to asthma.

A comparative histological analysis of human pulp following direct pulp capping with Propolis, mineral trioxide aggregate and Dycal.

BACKGROUND: Permanent teeth pulp exposures have traditionally been treated with calcium hydroxide pulp capping. The aim of this study was to investigate the response of human pulp tissue which were mechanically exposed to a new material, Propolis and compare it with two existing and commonly used pulp capping agents (mineral trioxide aggregate and Dycal). METHODS: Thirty-six intact human premolars were mechanically exposed. Teeth were divided into six groups of 6 teeth each and were capped with Propolis, mineral trioxide aggregate and Dycal. Final restoration was done with posterior composite resin using light cured glass ionomer cement as a liner. The teeth were then extracted on the 15th or the 45th day and processed for histological evaluation. RESULTS: Differences in inflammatory response and dentine bridge formation of the exposed pulp to the three different materials were statistically calculated using chi-square test and were found to be non-significant. There was more pulp inflammation in teeth treated with Dycal than with Propolis and MTA on the 15th as well as on the 45th day. Propolis and MTA showed bridge formation in more teeth, and the bridges were in closer proximity to pulp capping material than teeth treated with Dycal on the 45th day. CONCLUSIONS: The response of pulps to Propolis as a pulp capping agent was comparable to MTA and Dycal.

Bilateral maxillary paramolars and endodontic therapy: a rare case report.

Supernumerary paramolars are a rare anomaly of the maxillofacial complex. They are more common in the maxilla than the mandible. This article reports a rare case of bilateral maxillary paramolars, their complications and management.

Management of foreign body aspiration or ingestion in dentistry.

Foreign body aspiration or ingestion can be a potential complication during routine dental treatment. The handling of dental objects requires particular care, especially where the patient is supine or semi-recumbent. Dentist must be able to manage emergency situations in which patients accidentally swallow dental instruments or materials during treatment and procedures. This article reviews the complications, management and prevention of aspiration or ingestion of foreign bodies.

A conservative method to reproduce lost gingival tissue--an innovative approach.

One of the greatest assets a person can have is a smile that shows beautiful, natural teeth. The restoration of a smile is one of the most appreciated and gratifying services a dentist can render. The positive psychologic effects of improving a patient's smile often contribute to an improved self image and enhanced self esteem. Periodontal attachment loss in the maxillary anterior region can often lead to esthetic and functional clinical problems. Lifelong motivation is essential to the supportive therapy for these patients, and the maintenance of good esthetics, combined with conducive to maintaining long term dental and professional health. This paper aims to demonstrate an innovative treatment option for dealing with aesthetic challenges posed by a patient.

Delayed replantation: can it be a success?

This case report describes delayed replantation of an avulsed maxillary central incisor in a 17-year-old male patient following an injury on fall one day earlier. Avulsed maxillary right permanent central incisor was replanted back into the socket after extra-oral root canal treatment. One year follow up showed validity of treatment, with no evidence of resorption in the replanted tooth.

Asthma and dental erosion.

Asthma is a chronic inflammatory condition of the airway, characterised by the presence of airflow obstruction which is variable over short periods of time, or is reversible with treatment. Medication comprises of bronchodilators, corticosteroids and anticholinergic drugs. Most asthma drugs are inhaled using various forms of inhalers or nebulizers. Inhaled drugs must be used regularly. The effects of these drugs on the dentition such as tooth decay and erosion have been a subject of debate among dental practitioners. Asthmatic medications can place the patient at risk of dental erosion by reducing salivary protection against extrinsic or intrinsic acids. Asthmatic individuals are one of the higher risk groups suffering from dental erosion. Therefore patients with bronchial asthma should receive special prophylactic attention. This article presents a case of an asthmatic with dental manifestations and reviews the possible causes and management of the same.