Biomedical subjects

M G Botelho

Publications and source records attributed to M G Botelho.

5 recordsLinked to original sources

PubMed2001

Assessment of the use of problem-orientated, small-group discussion for learning of a fixed prosthodontic, simulation laboratory course.

AIM: To evaluate a simulation laboratory course that used student-centred small-group problem-orientated discussion activities as the main medium of instruction. METHODS: A structured questionnaire using a six-point Likert scale with 30 statements relating to a fixed prosthodontics course was distributed to 4th-year and 5th-year students who had completed the course. RESULTS: A 93% response rate was achieved for both years with a mean score for the 4th-year being 94.2 (+/- 13.7) and the 5th-year 107.5 (+/-16.9). The differences between the scores of both years are highly significant (P = 0.0006) indicating that the 5th-year were more favourable about the course and learning approach used. Consistency and reliability of the questionnaire was judged reliable according to Cronbach's alpha (4th-year = 0.7, 5th-year = 0.83). Many aspects of the small-group student-centred activities were highly valued by students however, students expressed a preference for learning and interacting with teachers than colleagues. CONCLUSION: Small-group student-centred learning activities were reported as creating an active, safe learning environment with beneficial opportunities for peer-peer interaction such as questioning, teaching and learning from students. However, students expressed a preference for teacher-centred information dissemination and activities. An understanding of the rationale of student dependence to teacher-centred learning may allow improved modifications in a student-centred learning environment.

Denture, Partial, Fixed↗

PubMed2000

Fractional inhibitory concentration index of combinations of antibacterial agents against cariogenic organisms.

OBJECTIVES: To examine the inhibitory effects between paired combinations of four antibacterial agents that have been investigated in dentistry against six bacteria associated with dentinal caries. METHODS: The antibacterial agents tested were: chlorhexidine dihydrochloride, benzalkonium chloride, cetrimide and cetylpyridinium chloride. Two organisms each belonging to Streptococcus, Lactobacillus and Actinomyces species were evaluated against these agents. A checkerboard microtitration method was used to determine the minimum inhibitory concentration and fractionary inhibitory concentration (FIC) and summation operator FIC index of the paired combinations of antibacterial agents against the six species of bacteria. Appropriate controls were included. The summation operator FIC index was then used to determine if synergy, antagonism, or indifference occurred as a result of interactions between the antibacterial agents and the test organisms. RESULTS: The data from a total of 295 test results were evaluated. Using summation operator FIC values for synergy as < or = 0.5 and antagonism as > 4.0 as recommended by The American Society for Microbiology, no significant synergistic or antagonistic interactions were observed between the paired antibacterial agents when tested against selected organisms. However, a tendency for an additive antibacterial effect was observed with approximately a third of the test results. Nonetheless, no combination of antibacterial agents appeared to be superior to any other. CONCLUSIONS: According to these in vitro results, there appears to be no beneficial effect of combining the antibacterial agents against the individual cariogenic micro-organisms selected. However, it may be beneficial to use combined antibacterial agents that have a broader range of activity against an ecosystem of bacteria than using individual agents.

Actinomyces↗

PubMed2000

The minimum inhibitory concentration of oral antibacterial agents against cariogenic organisms.

The minimum inhibitory concentrations (MIC) of eight common dental antibacterial agents against three genera of bacteria which have been implicated in dentine caries, namely streptococci, lactobacilli and actinomycetes were investigated. The ultimate aim was to determine the most appropriate antibacterial agent which could be added to dental restorative materials for filling cavities where there was residual dentine caries. The antibacterial agents tested were chlorhexidine diacetate, chlorhexidine dihydrochloride, chlorhexidine gluconate, benzalkonium chloride, cetrimide, cetylpyridinium chloride, thymol and sodium hypochlorite. Thymol and sodium hypochlorite did not inhibit microbial growth at any of the concentrations tested. For the active antibacterial agents tested the MIC values against lactobacilli and streptococci were 0.25 microg/ml to 8.0 microg/ml and for actinomycetes 0.125 to 8.0 microg/ml. These results illustrate the wide spectrum of sensitivity of caries associated bacteria against dental antibacterial agents. From the MIC values alone, it is difficult to recommend which of the active antibacterial agents would be most effective in eliminating cariogenic organisms.

Actinomycetales↗

PubMed1999

Embedded problem-based learning of a clinical subject.

A problem-based learning approach was used for the 'teaching' of a fourth-year bridge course in an attempt to improve student learning and academic performance in the clinical environment. The introduction of problem-based learning requires careful planning as to the desired educational objectives and design.

Curriculum↗

PubMedDate not supplied

Two-unit cantilevered resin-bonded fixed partial dentures--a retrospective, preliminary clinical investigation.

PURPOSE: The aim of this study was to retrospectively evaluate the clinical retention and abutment movement of 2-unit cantilevered resin-bonded fixed partial dentures (FPD) that were inserted at Prince Philip Dental Hospital in Hong Kong. MATERIALS AND METHODS: Of 45 patients who were identified from a hospital computer search after receiving a 2-unit cantilevered resin-bonded FPD, 31 were clinically examined (33 FPDs). For each patient the following data were recorded: gender, age, cementation date, endodontic treatment if performed, bone support, tooth mobility, and FPD tipping or drifting. Data about any debonds with subsequent treatment and patient satisfaction on a 10-point scale were also recorded. RESULTS: The mean service life for the 33 prostheses was 30 +/- 18 months, with a range of 72 days to 67 months. One prosthesis debonded, resulting in a clinical retention rate of 97%. No rotation, drifting, or tipping was observed for any of the prostheses during the short period of this study. CONCLUSION: Two-unit cantilevered resin-bonded FPDs are successful in the short term, but further research is required to determine if they offer a viable alternative to fixed-fixed resin-bonded FPD designs.

Adolescent↗