Endodontic 'Solutions'. Part 2:An audit comparing current practice in Belfast with UK and Republic of Ireland Dental Schools

Endodontic lubricants, irrigating solutions and medicaments help reduce the microbial load within root canals. Primary and secondary cases involve different microbes. Each'solution'or combinations thereof could play a significant role but no detailed guidelines exist on their use. An audit was undertaken to compare current practice in Belfast Dental School to the others across the UK and Republic of Ireland (ROI). This audit highlighted three main differences between Belfast and other dental schools. Many other institutions utilized other irrigants besides sodium hypochlorite (NaOCl), different intracanal medicaments, including calcium hydroxide, and higher concentrations of NaOCl. Having gathered this information, we ask, 'Is there sufficient evidence to change the endodontic regime currently used at Belfast Dental School?'. Using the findings from the literature review (Part 1), we introduce new evidence-based protocols for primary and secondary cases for use in Belfast Dental School. Clinical Relevance: In the absence of detailed clinical guidelines on the use of endodontic lubricants, irrigants and medicaments in primary and secondary cases, it is important to be aware of current practice in UK and ROI dental schools where dentists and specialists are trained.

Dental erosion among 12-14 year old school children in Khartoum:A pilot study

Objectives: To investigate dental erosion among 12-14 year old Sudanese school children and evaluate the associated risk factors. Basic Research Design: Cross sectional survey in secondary schools in Khartoum city, Sudan. Method and Participants: A sample of 157 school children was obtained from both private and public schools. Erosion on the labial and palatal surfaces of maxillary incisors was measured by criterion based on the Smith and Knight Tooth Wear Index. Dietary intake and other related factors were assessed using a questionnaire. Results: The overall erosion prevalence in this group was 66.9%, of which 45.2% was mild and 21.7% was moderate erosion. A strong association was found between erosion and private schooling (higher socioeconomic groups), carbonated drinks, herbal hibiscus drink and traditional acidic food consumption. Conclusion: There was a high prevalence of dental erosion among Sudanese school children which was mild to moderate in severity and was strongly associated with acidic dietary intake © BASCD 2007.

Human dental pulp fibroblasts express the "cold-sensing" transient receptor potential channels TRPA1 and TRPM8.

Abstract
INTRODUCTION:
Transient receptor potential (TRP) channels comprise a group of nonselective calcium-permeable cationic channels, which are polymodal sensors of environmental stimuli such as thermal changes and chemicals. TRPM8 and TRPA1 are cold-sensing TRP channels activated by moderate cooling and noxious cold temperatures, respectively. Both receptors have been identified in trigeminal ganglion neurones, and their expression in nonneuronal cells is now the focus of much interest. The aim of this study was to investigate the molecular and functional expression of TRPA1 and TRPM8 in dental pulp fibroblasts.
METHODS:
Human dental pulp fibroblasts were derived from healthy molar teeth. Gene and protein expression was determined by polymerase chain reaction and Western blotting. Cellular localization was investigated by immunohistochemistry, and TRP functionality was determined by Ca(2+) microfluorimetry.
RESULTS:
Polymerase chain reaction and Western blotting showed gene and protein expression of both TRPA1 and TRPM8 in fibroblast cells in culture. Immunohistochemistry studies showed that TRPA1 and TRPM8 immunoreactivity co-localized with the human fibroblast surface protein. In Ca(2+) microfluorimetry studies designed to determine the functionality of TRPA1 and TRPM8 in pulp fibroblasts, we showed increased intracellular calcium ([Ca(2+)](i)) in response to the TRPM8 agonist menthol, the TRPA1 agonist cinnamaldehyde, and to cool and noxious cold stimuli, respectively. The responses to agonists and thermal stimuli were blocked in the presence of specific TRPA1 and TRPM8 antagonists.
CONCLUSIONS:
Human dental pulp fibroblasts express TRPA1 and TRPM8 at the molecular, protein, and functional levels, indicating a possible role for fibroblasts in mediating cold responses in human teeth.

Treatment of a cochlear implant biofilm infection: a potential role for alternative antimicrobial agents

OBJECTIVE:
This study aimed to investigate antimicrobial treatment of an infected cochlear implant, undertaken in an attempt to salvage the infected device.

METHODS:
We used the broth microdilution method to assess the susceptibility of meticillin-sensitive Staphylococcus aureus isolate, cultured from an infected cochlear implant, to common antimicrobial agents as well as to novel agents such as tea tree oil. To better simulate in vivo conditions, where bacteria grow as microcolonies encased in glycocalyx, the bactericidal activity of selected antimicrobial agents against the isolate growing in biofilm were also compared.

RESULTS:
When grown planktonically, the S aureus isolate was susceptible to 17 of the 18 antimicrobials tested. However, when grown in biofilm, it was resistant to all conventional antimicrobials. In contrast, 5 per cent tea tree oil completely eradicated the biofilm following exposure for 1 hour.

CONCLUSION:
Treatment of infected cochlear implants with novel agents such as tea tree oil could significantly improve salvage outcome.

Evaluation of sources of uncertainties in microtensile bond strength of dental adhesive system for different specimen geometries

Objective: The aim of this research is to use finite element analysis (FEA) to quantify the effect of the sample shape and the imperfections induced during the manufacturing process of samples on the bond strength and modes of failure of dental adhesive systems through microtensile test. Using the FEA prediction for individual parameters effect, estimation of expected variation and spread of the microtensile bond strength results for different sample geometries is made. Methods: The estimated stress distributions for three different sample shapes, hourglass, stick and dumbbell predicted by FEA are used to predict the strength for different fracture modes. Parameters such as the adhesive thickness, uneven interface of the adhesive and composite and dentin, misalignment of axis of loading, the existence of flaws such as induced cracks during shaping the samples or bubbles created during application of the adhesive are considered. Microtensile experiments are performed simultaneously to measure bond strength and modes of failure. These are compared with the FEA results. Results: The relative bonding strength and its standard deviation for the specimens with different geometries measured through the microtensile tests confirm the findings of the FEA. The hourglass shape samples show lower tensile bond strength and standard deviation compared to the stick and dumbbell shape samples. ANOVA analysis confirms no significant difference between dumbbell and stick geometry results, and major differences of these two geometries compared to hourglass shape measured values. Induced flaws in the adhesive and misalignment of the angle of application of load have significant effect on the microtensile bond strength. Using adhesive with higher modulus the differences between the bond strength of the three sample geometries increase. Significance: The result of the research clarifies the importance of the sample geometry chosen in measuring the bond strength. It quantifies the effect of the imperfections on the bond strength for each of the sample geometries through a systematic and all embracing study. The results explain the reasons of the large spread of the microtensile test results reported by various researchers working in different labs and the need for standardization of the test method and sample shape used in evaluation of the dentin-adhesive bonding system. © 2007 Academy of Dental Materials.

Analysis of the compressive behaviour of the three-dimensional printed porous titanium for dental implants using a modified cellular solid model

A set of cylindrical porous titanium test samples were produced using the three-dimensional printing and sintering method with samples sintered at 900 °C, 1000 °C, 1100 °C, 1200 °C or 1300 °C. Following compression testing, it was apparent that the stress-strain curves were similar in shape to the curves that represent cellular solids. This is despite a relative density twice as high as what is considered the threshold for defining a cellular solid. As final sintering temperature increased, the compressive behaviour developed from being elastic-brittle to elastic-plastic and while Young's modulus remained fairly constant in the region of 1.5 GPa, there was a corresponding increase in 0.2% proof stress of approximately 40-80 MPa. The cellular solid model consists of two equations that predict Young's modulus and yield or proof stress. By fitting to experimental data and consideration of porous morphology, appropriate changes to the geometry constants allow modification of the current models to predict with better accuracy the behaviour of porous materials with higher relative densities (lower porosity).

Skin-reducing mastectomy and one-stage implant reconstruction with a myodermal flap: A safe and effective technique in risk-reducing and therapeutic mastectomy

Introduction: Immediate reconstruction following mastectomy for breast cancer has been shown to be oncologically safe and associated with improved psychosocial outcomes for patients. Bostwick described a technique for one-stage implant based reconstruction, combining skin-sparing mastectomy with concurrent reduction of the skin envelope. This report reviews the experience of a single centre using skin-reducing mastectomy and one-stage implant reconstruction in both early stage breast cancer and risk-reducing mastectomy, with specific reference to frequency of complications, implant loss and oncological outcomes.

Methods and results: A retrospective review was undertaken to identify women who had undergone skin-reducing mastectomy and one-stage implant reconstruction using a de-epithelialised dermal flap, between October 2008 and October 2012. One hundred and four consecutive mastectomies, with reconstruction, were performed by two surgeons on 64 patients. No complications were seen in 43.8% of patients. At three months, four implants were lost (3.8% of breast reconstructions, 6.3% of patients), due to either peri-implant infection or mastectomy skin flap necrosis. One patient required unplanned return to theatre for evacuation of a haematoma. Minor mastectomy skin flap necrosis was seen in 10 breasts (9.6% of reconstructed breasts) and superficial wound infection in 8 breasts (7.7% of reconstructed breasts). All of these complications were managed conservatively and none required operative intervention. At a median follow up of 35 months (4-53 months) there had been one episode of ipsilateral axillary nodal recurrence.

Conclusion: One-stage implant reconstruction using a myo-dermal flap technique following skin-reducing mastectomy is safe and should be considered in selected patients. Most complications are minor and will resolve with conservative management. Major complications such as implant failure or immediate reoperation, were relatively uncommon (6.3% patients, 3.8% of reconstructed breasts). Early follow-up suggests that oncological outcomes are satisfactory, but longer follow-up is required to substantiate this. (C) 2013 British Association of Plastic, Reconstructive and Aesthetic Surgeons. Published by Elsevier Ltd. All rights reserved.

Augmentation mammoplasty: effect on diagnosis of breast cancer

Breast augmentation for cosmetic purposes is an increasingly common procedure in the USA and UK. In the USA in 2003, a total of 254 140 breast augmentation procedures were carried out [American Society of Plastic Surgeons, http://www.plasticsurgery.org/newsroom/ Procedural-Statistics-Press-Kit-Index.cfm9-1-2005; 2006.(1)]. It has been previously estimated that between 1 and 1.5 million women in the USA have prosthetic breast implants [Cook RR, Delongchamp RR, Woodbury M, et at. The prevalence of women with breast implants in the United States, 1989. J Clin Epidemiol 1995;48:519-25.(2)]. The UK National Breast Implant Registry has recorded a rise in the numbers of women receiving breast implants, with over 13 000 procedures registered in 2001; an estimated 77% of these were for cosmetic purposes. No association has been found between the presence of breast implants in a breast and an increased risk of breast cancer, and this subject has been comprehensively reviewed elsewhere [Hoshaw SJ, Klein PJ, Clark BD, et al. Breast implants and cancer: causation, delayed detection, and survival. Plast Reconstr Surg 2001; 107:1393-407.(3)]. However, as the population of women with breast implants ages, an increasing number of them will develop breast cancer; a reflection of the fact that the incidence of the disease increases with increasing age. Debate continues on the effect of breast implants on the efficacy of mammography in diagnosing breast cancer, and the role of other imaging techniques for this purpose, as well as the limitations that the presence of implants place on percutaneous biopsy techniques. We review the Literature on the radiological and tissue diagnosis of breast cancer in women with a history of previous augmentation mammaplasty. (c) 2007 British Association of Plastic, Reconstructive and Aesthetic Surgeons. Published by Elsevier Ltd. All rights reserved.