A blended learning course taught to different groups of learners in a dental school: follow-up evaluation.

This article reports the results of a follow-up study conducted to investigate students' perceptions about a blended learning health informatics course that combined online and traditional classroom instruction. The course is taught to five different groups of students at the School of Clinical Dentistry of the University of Sheffield each academic year: first-, third-, and fourth-year dental students, dental hygiene and therapy students, and postgraduate dental students. The goal of the study was to determine the impact of the modifications made to the course after the first year of implementation. To accomplish this goal, students' perceptions of this blended learning course were compared after the first and second implementations. The methodology used for this study was action research. The data were collected using three processes: questionnaires were used to collect contextual data from the students taking the course; a student-led, nominal group technique was used to collect group data from the participants; and a non-participant observer technique was used to record the context in which certain group and individual behaviors occurred. Depending on group assignment, between 41.5 and 91.5 percent of students believed that the blended-learning course had added to their skills. The online learning environment was perceived as a useful resource by 75 percent of students in four of the five student groups, but only 45 percent of the fourth-year dental students indicated it was a useful resource. The perceived lack of sufficient online support material was one of the main concerns of the students at the nominal group evaluation sessions. The non-participant observer technique identified different engagement levels among the student groups. Discernible differences were identified, with improvement in some areas and a decline in others compared to a previous evaluation. The change in the delivery method influenced the students' comprehension of the material negatively and the learning environment positively, but did not influence online collaboration among students.

Efficacy of two alcohol-free cetylpyridinium chloride mouthwashes - a randomized double-blind crossover study.

AIM: (1) To determine the plaque inhibition properties of two formulations of alcohol-free mouthwash [0.1% w/w cetylpyridinium chloride (CPC) (B) and 0.05% w/w CPC (A)] versus a placebo mouthwash (C). (2) To compare the plaque-inhibiting activity between these two new CPC mouthwashes. MATERIAL AND METHODS: A double-blind, crossover study with three 1-week periods was used. Subjects were randomly assigned to one of the following groups. Group 1 (n=10) received the mouthwashes A, C and B in the periods 1, 2 and 3, respectively, group 2 (n=11) received the mouthwashes in the order B, A, C, while group 3 (n=11) received the mouthwashes in the order C, B, A. Mean plaque areas and Quigley & Hein plaque index scores were analysed using anova (analysis of variance). Measurements were made at the start of each period (baseline) and at 16, 24 and 40 h. RESULTS: Mean plaque scores were similar across the groups at baseline. At all time points thereafter, volunteers using mouthwash A or B had significantly lower plaque areas and plaque index scores than those using mouthwash C (p<0.05), but there were no significant differences between the test formulations. At 16 h, the reduction in plaque area relative to mouthwash C was 22% for mouthwash A and 18% for mouthwash B; at 24 h, 11% for mouthwash A and 15% for mouthwash B; and at 40 h, 15% for mouthwash A and 16% for mouthwash B. CONCLUSIONS: The use of both CPC mouthwashes resulted in less plaque accumulation compared with the control. There was no statistically significant difference in plaque accumulation between the two CPC mouthwashes.

Evaluating a blended-learning course taught to different groups of learners in a dental school.

The purpose of this study was to present and evaluate a blended-learning course developed for undergraduate (B.D.S.), postgraduate, and diploma (hygiene and therapy) students at the University of Sheffield School of Clinical Dentistry. Blended learning is the integration of classroom face-to-face learning with online learning. The overall methodology used for this study was action research. The data were collected using three processes: questionnaires to collect contextual data from the students taking the course; a student-led, nominal group technique to collect group data from the participants; and a non-participant observer technique to record the context in which certain group and individual behaviors occurred. The online component of the course was accepted as a valuable resource by 65 percent of those responding. While online information-sharing occurred (31 percent of the students posted in forums), there was no evidence of online collaboration, with only 8 percent replying to forum postings. Accessibility of the online environment was one of the main concerns of the students at the nominal group sessions. Differences regarding overall engagement with the course between the student groups (years) were observed during the sessions. The majority of the students were satisfied with the Information and Communication Technologies (ICT) course. No statistically significant differences between males and females were found, but there were differences between different student cohorts (year groups).

Gingival squamous cell carcinoma: diagnostic delay or rapid invasion?

BACKGROUND: The similarity between gingival squamous cell carcinoma (GSCC) and more common periodontal lesions may lead to a delay in diagnosis or misdiagnosis. Neoplastic lesions of gingival tissues are frequently diagnosed at an advanced stage. METHODS: To assess the relative time from when patients first become aware of the problem to histopathologic diagnosis (total diagnostic time), 59 consecutive oral cancer cases were examined in this study. The following variables were considered: age, gender, smoking habits, tumor stage at diagnosis, and total diagnostic time. The median of the patients' total diagnostic time (1.5 months) was used as a cutoff point to distinguish between delayed and non-delayed cases. Analysis of the variables was undertaken using the Student t test and chi2 test, with a 95% confidence interval (CI). RESULTS: The total diagnostic time was <1.5 months for 75% of gingival carcinomas, 50% of tongue carcinomas, and 78% of floor-of-the-mouth carcinomas. It was >1.5 months for 25% of gingival carcinomas, 50% of tongue carcinomas, and 21% of floor-of-the-mouth carcinomas. No significant differences in time before diagnosis were found when gingival cancers were compared to other oral tumors (chi2=0.21; 95% CI=-0.40 to 0.26). However, by the time of diagnosis, gingival cancers had invaded adjacent structures more frequently than other oral cancers (chi2=13.51; 95% CI=0.18 to 0.85). CONCLUSIONS: The gingival location of oral squamous cell carcinoma (OSCC) was associated with advanced stages at the time of diagnosis, due to early invasion of contiguous bone tissue (T4-primary tumor). This would indicate that even earlier referral and diagnosis are necessary.

Clinical evaluation of the stain removing ability of a whitening dentifrice and stain controlling system.

OBJECTIVES: This study aimed to evaluate the stain removing/controlling properties of a whitening dentifrice and a stain controlling system, in a parallel group, multiple use study. METHODS: Subjects (63), were stratified according to baseline stain scores and randomly allocated to a group, A (standard dentifrice), B (whitening/stain removing dentifrice) or C (whitening/stain removing dentifrice, tooth polish, tooth polisher and whitening/stain removing mouthwash). At each attendance, extrinsic stain was scored blind by a trained and calibrated examiner using the Shaw and Murray Stain Index, under constant lighting conditions. In addition, whiteness was measured using a colorimeter. RESULTS: The toothpaste regimens were well balanced at baseline (p=0.811). At 4 weeks, Regimens B and C had significantly less stain than A (p<0.05). Lower stain values were maintained/reduced for regimens B and C by week 6, with changes from baseline significantly greater than for Regimen A. When lightness was assessed by colorimeter, Regimen C was also found to be significantly whiter than Regimen A (p<0.05). CONCLUSIONS: It was concluded that both whitening regimens had a significant effect on reducing tooth staining and improving whiteness over the 6 week time period.

Interleukin 1 and receptor antagonist levels in gingival crevicular fluid in heavy smokers versus non-smokers.

BACKGROUND/AIMS: This study aimed to investigate the concentration of the cytokine interleukin (IL)-1beta and its receptor antagonist IL-1ra in gingival crevicular fluid (GCF) in patients with adult periodontitis who were heavy smokers compared with non-smokers. METHOD: GCF samples were collected from two groups of subjects: smokers and non-smokers. Thirty-nine GCF samples were harvested from 13 subjects with moderate to severe adult periodontitis who were heavy smokers. A further 30 GCF samples were harvested from 10 subjects with moderate to severe adult periodontitis who were non-smokers. Subjects were selected from both genders and none had any relevant systemic illness, were pregnant, had recent medication or had received any periodontal therapy in the preceding 3 months. One deep bleeding site, one deep non-bleeding site and one healthy site were investigated in each subject. Clinical measurements were recorded for each site, after obtaining a GCF sample using a Periopaper strip. IL-1beta and IL-1ra were quantified using new commercially available ELISA kits (Quantikine), and could be detected in all samples. RESULTS: For smokers, the mean concentrations for IL-1beta were 2714.5 (SD 4416.2) pg/ micro L for healthy sites, 37.0 (SD 57.2) pg/ micro L for non-bleeding periodontitis sites and 24.5 (SD 29.2) pg/ micro L for bleeding periodontitis sites. The concentrations of IL-1beta for non-smokers for the same category of sites were 393.8 (SD 867.1), 74.2 (SD 107.0) and 73.1 (SD 61.0) pg/ micro L, respectively. The mean concentrations of IL-1ra for smokers were 5.8 x 10(5) (SD 9.7) pg/ micro L for healthy sites, 2.2 x 10(5) (SD 0.15) pg/ micro L for deep non-bleeding sites and 0.19 x 10(5) (SD 0.07) pg/ micro L for deep bleeding sites. The concentrations for non-smokers were: 4.1 x 10(10) (SD 3.8), 18.1 x 10(5) (SD 20.4) and 3.2 x 10(5) (SD 2.3) pg/ micro L, respectively. Significance levels of P < 0.05 were found for comparisons of healthy vs. deep bleeding and deep non-bleeding sites for IL-1beta and IL-1ra in smokers, before adjustments for multiple testing. However, none of these comparisons reached statistical significance following adjustments for multiple testing. P < 0.05 for the correlation between IL-1beta and IL-1ra at healthy sites in smokers only. Differences in GCF concentrations for IL-1beta in smokers vs. non-smokers were significant for deep bleeding sites only (P < 0.05), the mean concentration of IL-1beta being lower in GCF from smokers vs. non-smokers. All differences in GCF concentrations of IL-1ra reached statistical significance for smokers vs. non-smokers. The mean concentrations of IL-1ra in GCF were lower in smokers compared with non-smokers for all categories of sites. CONCLUSIONS: A decreased concentration of IL-1beta and also IL-1ra was found in GCF from periodontitis sites compared to healthy sites in smokers and in non-smokers, although this did not reach statistical significance following adjustments for multiple testing. For comparisons between heavy smokers and non-smokers, statistically significant differences were found in the GCF concentrations of IL-1beta from deep bleeding sites only. Statistically significant differences were found in the IL-1ra concentrations for smokers vs. non-smokers for all categories of sites.