Comparison of capsule-mixed versus hand-mixed glass ionomer cements Part II: Porosity

Glass ionomer restorative cements (GIC) are routinely used in dental practice. During mixing, air incorporation may lead to higher porosity with subsequent weakening of the cement. The degree of porosity will determine whether capsule-mixed or hand-mixed GIC are mechanically stronger for clinical use. To compare the porosity of four commercially available dental glass ionomer cements, supplied in both hand mix and capsule-mix formulations, by evaluating number of voids (%), total volume of voids (mm3 ) and volume percentage of voids (%). Eighty samples were manufactured from hand-mixed GIC: Riva Self Cure; Fuji IX GP ; Ketac Universal, Ketac Molar Easymix, and equivalent capsule-mixed GIC: Riva Self Cure; Fuji IX GP ; Ketac Universal Aplicap and Ketac Molar Aplicap. Micro-CT scanning was used to evaluate porosity. The number of voids (mm3 ), total volume of voids (mm3 ) and the volume percentage of voids (%) were calculated

Comparison of capsule-mixed versus hand-mixed glass ionomer cements Part 1: compressive strength and surface hardness

Dental restorative glass ionomer cements (GIC) are available as hand-mixed or capsulated products. Capsulation facilitates uniform ratios of powder to liquid, that should result in an optimal end-product. If this is evident, the degree to which capsulated GIC are mechanically stronger will aid in deciding when to use them instead of the handmixed variety. The compressive strength and surface hardness of handmixed GIC were compared to capsule-mixed equivalents. Eighty samples were manufactured from hand-mixed GIC: Riva Self Cure; Fuji IX GP; Ketac Universal, Ketac Molar Easymix, and equivalent capsule-mixed GIC: Riva Self Cure; Fuji IX GP; Ketac Universal Aplicap and Ketac Molar Aplicap. Compressive fracture strength was tested using a universal testing apparatus. Surface hardness was measured with a Vickers digital micro-hardness tester Significant differences were found between the compressive strength of RSCH and RSCC (P = 0.027), and, between KMH and KMC (P < 0.001). Significant differences in surface hardness were found between FIXH and FIXC (P = 0.031),KUH and KUC (P < 0.001), as well as KMH and KMC (P = 0.006). Three capsulated forms of GIC (RSCC, KUC, KMC) demonstrated superior mechanical properties. Capsulated GIC offer advantages which may translate to clinical application

Sterilisation and single-use of endodontic files - a short report

INTRODUCTION: In many countries, endodontic files continue to be sterilised and reused in multiple clinical cases as the alternative of single-use of these instruments is avoided due to financial reasons. METHODS: A survey was performed including South African general dental practitioners and specialist prosthodontists to determine the current endodontic file sterilisation methods in place and the adoption rate of single-use protocols of both hand and engine-driven instruments. RESULTS: The majority of respondents (76.6%, n=141/184) indicated autoclaving endodontic files prior to reuse. Almost a quarter of the respondents (23.4%, (n=43/184) used only cold sterilisation. Some respondents (2,8%, n=5/181) indicated not sterilising their files at all. A low number of respondents had adopted the single-use of endodontic hand files (10.9%, n=20/184). Engine-driven files were used only once and discarded by 18.5% (n=34/184) of respondents. CONCLUSION: It appears that, at times, acceptable infection prevention and control practices regarding the sterilisation these instruments are not necessarily being adhered to. The adoption of single-use protocols of endodontic files in a South African dental setting is higher than previously reported

A case study of change management effectiveness within the NHS

In the UK healthcare sector structural change has become increasingly frequent and there are few employees in the NHS who have not experienced this in some form. Anecdotally, many of those affected report negative consequences that have potentially adverse effects on service delivery. The purpose of this research is to evaluate the effectiveness of the management of change in one specific healthcare setting, the Public Health Laboratory Service. It also seeks to make recommendations for managing organisational change that are applicable elsewhere and to consider the validity of existing change management models. This research is set in the context of the creation of a new Special Health Authority (the Health Protection Agency, HPA) and other related changes as outlined in the Chief Medical Officer's strategy document Getting Ahead of the Curve (Department of Health, 2002). The research seeks to analyse this change programme from the perspective of one group of affected individuals, employees of the Public Health Laboratory Service. Recommendations for future management of change at the HPA and elsewhere are made, with observations about the validity of existing change management models. The core contribution of this research is that it has added to the general body of knowledge about organisational change and its management. This is of value to those working in the UK healthcare and wider public sector. Specific recommendations for future research are made