Exploring Students' Views of Portfolio Assignments to Foster Self-reflection in Preclinical Dental Education.

OBJECTIVES: Portfolios, collected evidence of students' learning and achievement, have been widely used in health profession education for learning and assessment purposes. However, little has been documented on their use to foster self-reflection in preclinical dental education. This exploratory study assessed students' views of portfolio assignments to foster self-reflection in preclinical operative dentistry courses. METHODS: Participants were first- (Y1) and second-year (Y2) undergraduate dental students who completed a preclinical operative course in the College of Dentistry at the University of Saskatchewan. These students were asked to answer an online post-course survey to assess their view of the portfolio assignments that were part of the course. Specifically, they were asked to rate 13 statements related to experiential and instrumental outcomes of portfolio assignments (outcome evaluation) and their level of comfort with the activities involved in completing the assignments (process evaluation) on a 5-point Likert scale from strongly agree (1) to strongly disagree (5). Descriptive statistics (standard deviation, mean) were used to report the data. A t test was performed to assess statistical differences between Y1 and Y2 dental students. RESULTS: Of the 69 students enrolled in the preclinical courses, 25 Y1 and 25 Y2 students completed the survey (72.5%). No statistically significant differences between the ratings of Y1 and Y2 students were observed (p ≥ 0.05). Their combined ratings showed that students enjoyed the portfolio assignments, found them beneficial and felt comfortable performing the activities involved in developing the portfolios (mean scores 1.54-2.42). CONCLUSION: Students viewed portfolio assignments as a learning tool to foster self-reflection in preclinical operative dentistry courses. Further research is needed to measure the effects of portfolio assignments on student learning, including self-reflection.

Comparison of the contact angle of water on set elastomeric impression materials.

PURPOSE: The hydrophilicity of some elastomeric impression materials has not been fully established. The purpose of this study was to measure and compare the advancing contact angle of water on the surface of several set elastomeric impression materials. MATERIALS AND METHODS: We tested various consistencies of vinyl polysiloxane (VPS; Imprint 4) and vinyl polyether silicone (VPES; EXA'lence) with a polyether (PE; Impregum Soft) control. Impression discs (25.07 mm) were made using a metal die and ring. Deionized ultra-filtered water was placed on each disc and contact-angle measurements were made at 0, 15, 30, 45 and 60 s using a video contact angle drop shape analysis machine. The data were analyzed using repeated ANOVA and a post-hoc test with Bonferroni correction. RESULTS: VPS contact angles reached a mean of 10.1° ± 0.2° at 60 s vs. 40.7° ± 0.1° for VPES. Overall, VPS contact angles were smaller than those for VPES at all measured times. However, heavy and super quick heavy VPS had much higher contact angles at 0 s compared with other VPS consistencies. There was a significant difference in contact angles between VPS and VPES (mean difference 33.9°, p < 0.05) and between VPS and PE (mean difference 32.8°, p < 0.05) but not between VPES and PE (P = 0.196). VPS heavy and super quick heavy were significantly different from other VPS materials (p < 0.05), but not from each other (p = 1.00). CONCLUSIONS: Set VPS is more hydrophilic than VPES. Contact-angle values of VPS indicated super hydrophilicity. VPES was hydrophilic, with measurements similar to the PE control. Thus, VPS impression materials may be excellent in terms of spreading and copying wet surfaces.

The effect of prolonged storage and disinfection on the dimensional stability of 5 vinyl polyether silicone impression materials.

PURPOSE: Vinyl polyether silicone (VPES) has a different composition from other elastomeric impression materials as it combines vinyl polysiloxane (VPS) and polyether (PE). Therefore, it is important to study its properties and behavior under different test conditions. This study investigated the dimensional stability of 5 VPES consistencies when stored for up to 2 weeks, with and without using a standard disinfection procedure. MATERIALS AND METHODS: 40 discs of each VPES consistency (total 200) were made using a stainless steel die and ring as described by ANSI /ADA specification No. 19. 20 discs of each material were immersed in a 2.5% buffered glutaraldehyde solution for 30 minutes. Dimensional stability measurements were calculated immediately after fabrication and repeated on the same discs after 7 and 14 days of storage. The data was analyzed using two-way ANOVA with a significance level set at α = 0.05. RESULTS: The discs mean contraction was below 0.5% at all test times ranging from 0.200 ± 0.014 to 0.325 ± 0.007. Repeated measures ANOVA showed a statistically significant difference after 2-week storage between the disinfected and non-disinfected groups (P < .001). Although there was no statistically significant difference between the materials at the time of fabrication, the contraction of the materials increased with storage for 1 and 2 weeks. CONCLUSION: The dimensional changes of VPES impression discs after disinfection and prolonged storage complied with ANSI/ADA standard. The tested VPES impression materials were dimensionally stable for clinical use after disinfection for 30 minutes in glutaraldehyde and storage for up to 2 weeks.

CAREER PLANS OF GRADUATES OF A CANADIAN DENTAL SCHOOL: PRELIMINARY REPORT OF A 5-YEAR SURVEY.

OBJECTIVE: Comprehensive data on the characteristics and opinions of graduating dental students in Canada are lacking. Specifically, only minimal information is available on graduates' immediate career plans and factors that may influence their decisions regarding these plans. Our aim was to gather such data to allow better understanding of this issue and improve the design of future studies on this topic. METHODS: The Career Development Committee at the school of dentistry, University of Alberta, designed a short survey to be administered to graduating students over 5 years to gain insight into their immediate career plans and opinions on career services at the school. Preliminary results from 2012-2014 are reported here. RESULTS: With a response rate of close to 90% (n = 99/111), the data reveal considerable differences in immediate career plans between the surveyed students and those in other schools in Canada and the United States. Of the students, 89% were planning to work in a general dental practice and only 9% were planning to enroll in advanced education, including general practice residency training. CONCLUSION: More research is needed to better understand the factors affecting career path decisions of students.

Surface Detail Reproduction and Effect of Disinfectant and Long-Term Storage on the Dimensional Stability of a Novel Vinyl Polyether Silicone Impression Material.

PURPOSE: This study investigated the surface detail reproduction and dimensional stability of a vinyl polyether silicone (VPES) in comparison to a vinylpolysiloxane (VPS) material as a function of prolonged storage for up to 2 weeks. MATERIALS AND METHODS: Heavy-body VPES (EXA'lence(TM) Fast Set) and VPS (Imprint(TM) 3 Quick Step) were compared. Forty impression ingots of each material were made using a stainless steel die as described by ANSI/ADA specification No. 19. Twenty impressions of each material were disinfected by immersion in a 2.5% buffered glutaraldehyde solution. Surface quality was assessed and scored immediately after making the ingots. Dimensional stability measurements were made immediately and repeated on the same ingots after 7 and 14 days storage in ambient laboratory conditions. Data were analyzed using the D'Agostino and Pearson omnibus normality test followed by two-way repeated measures ANOVA with post hoc Bonferroni tests. Values of p < 0.01 were deemed to be significant. RESULTS: Disinfected VPES and VPS specimens had significantly reduced dimensional changes at 7 and 14 days when compared with the nondisinfected ones (p < 0.0001). The dimensional stability of both materials was within ANSI/ADA specification No. 19's acceptable limit throughout the 2-week test period, regardless of whether they were disinfected. Out of the initial 80 ingots, 8 VPES and 1 VPS ingot scored a 2 on the surface detail test, while the remaining 71 ingots scored 1. CONCLUSIONS: Heavy-body fast-set VPES experienced minimal contraction in vitro after prolonged storage, though surface detail scores were not as consistent as those of the VPS tested. The least contraction occurred when the material was examined immediately after ingot production.

An in vitro study on the dimensional stability of a vinyl polyether silicone impression material over a prolonged storage period.

STATEMENT OF PROBLEM: A new elastomeric impression material, a vinyl polyether silicone, has been commercially introduced. Its dimensional stability at different pouring times has not been reported. PURPOSE: The purpose of this study was to evaluate the dimensional stability of vinyl polyether silicone (VPES) impressions as a function of delayed-pouring time for up to 2 weeks after performing a recommended clinical disinfection procedure. MATERIAL AND METHODS: The 3 medium-body impression materials tested were EXA'lence 370, Imprint 3, and Impregum Penta soft. Impressions of a cylindrical metal model, which served as a control, were made and poured in a Type V stone after being disinfected in 2.5% buffered glutaraldehyde solution. Die diameter and anteroposterior and cross-arch measurements on each cast were made and compared to direct measurements of the control with a digital micrometer. The linear dimensional changes were compared and analyzed by using the Mann-Whitney U test (α=.05). RESULTS: Considering the absolute values for the mean percentage dimensional change, VPES cast measurements were below 1.0% (P<.001), with the majority being minimal (≤0.34%) at all pour times. Measurements of the casts were larger than those of the control in all but one specimen. The percentage dimensional changes of the individual die diameters were higher than those of the anteroposterior and cross-arch linear measurements. Casts produced from VPES impressions had similar dimensional changes to those of VPS at 1 week of storage and similar changes to those of PE at 2 weeks of storage. The behavior of VPES impressions varied from being the most accurate at immediate-pour to gradually exhibiting higher dimensional changes as time progressed. CONCLUSIONS: Casts produced from a disinfected regular set VPES (EXA'lence 370 monophase) demonstrated excellent dimensional stability at different pour times and were comparable to the tested VPS and PE impression materials.

Dimensional accuracy of 2 irreversible hydrocolloid alternative impression materials with immediate and delayed pouring.

OBJECTIVE: To assess dimensional accuracy and stability of 2 irreversible hydrocolloid alternative impression materials with immediate and delayed pouring. METHODS: Two alternative impression materials, AlgiNot FS and Position Penta Quick, were compared with a traditional irreversible hydrocolloid, Jeltrate Plus antimicrobial alginate. Impressions were made of a metal model with 4 cylinders of known dimensions, with pouring performed immediately or after 4 hours of storage. A digital micrometer was used to measure cylinder diameter on the model and the poured casts. Dimensional changes were analyzed according to American National Standards Institute/American Dental Association (ANSI/ADA) Specification 19 (2004 version) (α=0.05). RESULTS: There were significant differences among the 3 materials, between the 2 pour times and as a function of storage time (multivariate analysis of variance, p<0.001). One-way analysis of variance revealed no significant differences between the 2 alternative impression materials, but changes for these materials differed significantly from those for the traditional impression material for immediate (p<0.05) and 4-hour (p<0.001) pouring. Linear dimensional changes for the 2 substitute materials were within the limits of the ANSI/ADA specification. CONCLUSIONS: With immediate pouring, both alternative impression materials exhibited minimal dimensional changes, which were maintained or reduced with 4-hour pouring. For both pouring times, these changes were less than 0.5%. CLINICAL SIGNIFICANCE: The minimal dimensional changes observed with these irreversible hydrocolloid alternative impression materials after 4 hours of storage may save chairside time and help to produce accurate results for procedures such as partial denture framework, surgical guides, and pediatric and orthodontic devices.

Prediction of lower incisor proclination during Xbow treatment based on initial cephalometric variables.

OBJECTIVE: To predict lower incisor proclination from initial cephalometric values in Class II division 1 patients treated in phase I with the Xbow appliance. MATERIALS AND METHODS: Two hundred forty-nine mild to moderate Class II division 1 patients treated with the Xbow appliance as a phase I treatment were considered. Patients were in late mixed dentition or early permanent dentition. Commonly used cephalometric variables at T1 (before treatment) were used to predict lower incisor proclination after Xbow treatment (T2). A principal component analysis (PCA) was performed. The four extracted PCA components were skeletal component, incisal distance, anterior facial projection, and maxillo-mandibular relation. Thereafter, a multiple linear regression analysis (MLRA) was performed using the four extracted PCA components at T1 as predictor variables, and lower incisor inclination relative to the mandibular plane (L1-MP) at T2 as the dependent variable. RESULTS: The mean L1-MP at T1 was 95.46 degrees and the mean L1-MP at T2 was 98.51 degrees, resulting in a mean difference of 3.04 degrees. Only incisal distance and maxillo-mandibular relation PCA components had significance (P < .05) according to the MLRA. The overall model gave an adjusted R2 value (coefficient of determination) of 0.091. CONCLUSION: The best prediction model could account for only 9% of the total variability. Using common cephalometric variables at T1, average lower incisor proclination from Xbow treatment cannot be predicted in a clinically meaningful way.

Dimensional stability of irreversible hydrocolloid impression materials as a function of pouring time: a systematic review.

STATEMENT OF PROBLEM: Pouring time of irreversible hydrocolloid impressions differs depending on the brand and intended use, either of which may result in variable dimensional stability. PURPOSE: The purpose of this study was to investigate the available literature on dimensional stability of irreversible hydrocolloid impression materials as a function of pouring time and disinfectant solutions used. MATERIAL AND METHODS: Three electronic database searches (Medline, PubMed, and EMBASE) were conducted to identify in vitro peer-reviewed studies published in English between the early 1970s and October 2010. Selection criteria included in vitro studies, irreversible hydrocolloid as impression material, and storage time. Heterogeneity in the methodology of the selected studies precluded a meta-analysis. RESULTS: Of 62 initially selected studies only 18 were included. Traditional irreversible hydrocolloids were generally stable when poured immediately. However, stability decreased as time elapsed. New irreversible hydrocolloid substitutes appear to allow delay in pouring time and repouring of impressions without significant side effects. CONCLUSIONS: Shorter storage time of irreversible hydrocolloid impressions before pouring is desirable, although this may not be necessary for the extended-pour types. The lack of a standardized technique for studying the effect of storage condition, with or without the use of disinfectants, makes it difficult to make clear recommendations.

Dental arch space changes following premature loss of primary first molars: a systematic review.

PURPOSE: The purpose of this study was to consider the available evidence regarding premature loss of primary molars and the implications for treatment planning. METHODS: Electronic database searches were conducted--including published information available until July 2007--for available evidence. A methodological quality assessment was also applied. RESULTS: Although a significant number of published articles had dealt with premature primary molar loss, only 3 studies (including a total combined sample of 80 children) had the minimal methodological quality to be considered for this systematic review. CONCLUSION: A reported immediate space loss of 1.5 mm per arch side in the mandible and 1 mm in the maxilla--when normal growth changes were considered--was found. The magnitude, however, is not likely to be of clinical significance in most cases. Nevertheless, in cases with incisor and/or lip protrusion or a severe predisposition to arch length deficiency prior to any tooth loss, this amount of loss could have treatment implications.

Implant site development by orthodontic extrusion. A systematic review.

OBJECTIVE: To determine the effectiveness of orthodontic extrusion of nonrestorable teeth prior to implant placement for improving the alveolar bone and gingival characteristics of implant recipient sites. MATERIALS AND METHODS: Electronic database searches of the following databases were conducted with the help of a senior health sciences librarian: Medline, PubMed, EMBASE, Scopus, Web of Science, and CINAHL Plus. Hand searches of the reference lists of selected articles were also conducted. Abstracts that appeared to fulfill the initial selection criteria were selected for full article retrieval. Retrieved articles were then carefully evaluated, and more specific selection criteria were applied. The authors conducted the selection processes independently, and any differences were resolved through discussion. An analysis of timing, type, and magnitude of forces applied was sought. RESULTS: Eighteen articles were considered for review. Most of the selected articles were case reports or case series describing orthodontic extrusion of periodontally hopeless maxillary anterior teeth. The results of the reported cases were evaluated individually and collectively with regard to various hard and soft tissue implant site characteristics. Clinically significant gains in alveolar bone and gingival tissue were reported in all cases, resulting in significant quantitative and qualitative improvements in the implant sites. CONCLUSIONS: Based on the available literature, orthodontic extrusion of nonrestorable teeth prior to implant placement appears to be a viable alternative to conventional surgical augmentative procedures in implant site development. No direct comparison to any other method was found, and therefore no conclusion could be made about its relative efficacy.

Longevity of a maxillary 2-unit cantilever fixed partial denture: clinical report.

In this clinical report, we discuss the length of service and subsequent replacement of a maxillary anterior 2-unit cantilever fixed partial denture (FPD). The FPD provided 53 years of service to the patient and was finally replaced with a 2-unit porcelain-fused-to-metal (PFM) FPD. The original prosthesis replaced a missing maxillary lateral incisor using a partial coverage metal retainer, whereas the new FPD was designed with a complete coverage PFM retainer.