OAR@UM Collection:

The effectiveness of disinfection protocols and different disinfectants on dental impressions submitted to the laboratory.

Thu, 01 May 2014 00:00:00 GMT

Title: The effectiveness of disinfection protocols and different disinfectants on dental impressions submitted to the laboratory. Abstract: Purpose: Disinfection is highly important in dentistry, to avoid cross contamination both between the laboratory and the clinic, and between dental personnel. This study compared the efficacy of disinfection done in the laboratory and clinic together with the different disinfectants used. Materials and Methods: Impressions were taken from each of the 14 participants- 7 using Blueprint 20+ alginate and 7 using Affinis monobody addition silicone. 3 impressions were taken from each participant with 2 week intervals between each one. Every impression was then divided into 3; each part was subjected to spraying MD520, Minuten spray disinfectant or no disinfection (control) respectively. TSA media was used for suspending dilutions and result was found in CFU/cm2 Results: MD520 seemed to be 100% effective with only a few microbial colonies growing below the detection limit, while Minuten turned out to leave higher levels of bacterial growth with the microbial load turning out to be almost twice as much for alginate then polyvinylsiloxane (PVS) impressions. In addition alginate carried significantly more bacteria compared to PVS before subjected to any disinfection. Conclusion: This study showed that unlike disinfection with MD520 some degree of bacterial growth still remains after the use of Minuten; therefore handling of impressions in all settings should be done with care. The use of both disinfectants in combination should also be considered. Description: B.SC.(HONS)DENTAL TECH.

Dental students' compliance to impression disinfection procedures.

Thu, 01 May 2014 00:00:00 GMT

Title: Dental students' compliance to impression disinfection procedures. Abstract: This research study evaluates dental students' compliance to standard protocols with regards to dental impression disinfection at the University of Malta dental teaching clinic and teaching laboratory. Specially designed questionnaires were distributed among dental students, dental technology students and dental hygiene students. The data was analysed and an educational presentation of the infection control procedures was developed. Following the presentation, the questionnaire was then handed out again after one week from the presentation and then after one month. This assessed whether constant reminders are necessary to maintain a good working knowledge of infection control measures. The chi-square test was used for statistical analysis of data. Significance level was set at p<0.05. The response rate was 100%. According to the study. According to the present study 100% of dental students were immunized against Hepatitis B. They were very well aware of the sterilization methods, 85% were of the opinion that autoclave was the best method for sterilization. Examination gloved and facemasks were used by the majority for impression taking. Disinfection of impressions after removal form patient's mouth was practiced by the majority. Resource deficiency, time consuming and loss of precision and dimensional stability of the material was considered to be the reason for not following standard precautions. It was concluded that the knowledge of the students was good and there was increased awareness as far as sterilization and cross infection was concerned but when it comes to practice, it is lacking. Various reasons for not practicing universal precautions were resource deficiency and time consuming Description: B.SC.(HONS)DENTAL TECH.

Ion release from removable dental metal alloy prostheses in patients suffering from gastro-oesophageal reflux disease

Wed, 01 Jan 2014 00:00:00 GMT

Title: Ion release from removable dental metal alloy prostheses in patients suffering from gastro-oesophageal reflux disease Abstract: OBJECTIVES: This study investigated the release of metal ions from alloys used in removable dental prostheses and the potential effects on this ion release of gastro-oesophageal reflux disease (GORD). METHODS: 37 patients were recruited. Data was gathered through a questionnaire and clinical examination. Samples of metal alloy from the dentures and patient's saliva were collected. GORD was confirmed using the GerdQ questionnaire. Twelve (12) denture samples were characterized using Scanning Electron Microscopy & Energy Dispersive X-ray Spectroscopy, while 37 salivary samples were tested for metal ion concentrations using Inductively-Coupled Plasma - Emission Spectroscopy. RESULTS: Characterization of denture samples revealed the presence of two main alloys: nickel-chromium and cobalt-chromium. Nickel-chromium exhibited an etched surface pattern, while cobalt-chromium exhibited no apparent surface microstructural changes. The study revealed significant higher mean salivary levels of chromium (p=0.011) and cobalt (p=0.038) in patients wearing any metal alloy based denture, of chromium (p=0.047) and cobalt (p=0.013) in patients wearing a Co-Cr prosthesis and of chromium (p=0.034) and nickel (p=0.037) in patients wearing a Ni-Cr prosthesis. No significant differences were found in salivary metal ion levels of patients suffering from GORD. CONCLUSION: Nickel-chromium alloy is prone to acid etching in the oral cavity while cobalt-chromium alloy seems to be resistant. Cobalt, chromium and nickel are leached in saliva of patients making use of cast removable prostheses. The impact of gastric acid on metal ion release from dental metal alloys deserves further investigations. Description: M.SC.DENTAL SURGERY