Student Research Day


UNMC College of Dentistry Virtual Research Day

Friday, February 26, 2021

54th Annual Frank M. Wentz Student Scientific Program and Keynote Speaker Dr. Mark Herzberg

Event Summary

Event participants:

Research Day 2021 Program & Abstracts

Award Winners


1st Place - Jason Jurca, "Noncarious cervical lesions prevalence and related risk factors: a pilot cross-sectional study of post-orthodontic patients." Mentor: Dr. Luana Oliveira-Haas 

Authors: Jason Jurca, Dr. Luana Oliveira-Haas, Dr. Steven Haas and Dr. John Reinhardt.

The loss of dental hard tissue in the cervical region of the tooth – known a noncarious cervical lesions (NCCLs) – is an increasingly common finding in clinical practice, with prevalence rates of up to 85% in some populations. Even though NCCLs involve a majority of the populations and the necessity of dentists to constantly deal with this common pathology in their patients, there is still contention about the mechanisms and factors involved in the etiology and progression of these lesions. Furthermore, there are concerns about the durability of restorative materials and successful control and treatment of this pathology.

The purpose of this study is to determine the prevalence and risk factors associated with NCCLs in a cross-sectional study of 34 adult patients. A detailed inspection of the cervical area (buccal, lingual/facial) and occlusal surface of each tooth was performed. A questionnaire to collect information on socio-demographics, oral hygiene practices, orthodontic history, and dietary risk factors was distributed to correlate risk factors to initiation and progression of NCCLs. The chi-square test and logistic regression analysis will be used to analyze the data. Frequency distribution will be performed to evaluate NCCL prevalence and logistic regression will be used to identify predictors of NCCL development. A p value of <.05 will be considered to indicate statistical significance. The null hypothesis is that there is no relationship between risk factors and the occurrence of NCCLs. Data analysis is ongoing.

2nd Place - Jordan Verplank, "Engineered selective noise cancelling device to reduce long term hearing damage in dental settings." Mentor: Dr. Mark Beatty 

Authors: Jordan Verplank and Dr. Mark Beatty.

Problem Statement: Noise induced hearing loss (NIHL) is a controversial topic among dental professionals. The goal of this study is to determine the sound exposure among students at UNMC College of Dentistry, determine if the exposure levels are within the standard set by OSHA, and use the results from the study to engineer a selective noise cancelling device to reduce sound exposure in the dental setting.

Materials and Methods: The frequency of the high speed cutting (HSC) and non-cutting (HSNC), slow speed cutting (SSC) and non-cutting (SSNC), ultrasonic cutting (UC) and non-cutting (USNC), and model grinder (MG) were measured using Decibel X software for iOS. Cutting was performed on natural teeth ex vivo. The MG was tested using a 1x3cm block of silky rock, modeling stone, and mounting stone. The time weighted average (TWA) of sound exposure was calculated based on OSHA standards. MATLAB and LabView were used to model a selective noise cancelling device based on collected data.

Results: Data analysis ongoing. Conclusion: Data analysis ongoing.

3rd Place - Caleb McKinley & Lotte Sjulin, "The correlation between dental school application and success in dental school." Mentor: Dr. Merlyn Vogt 

Authors: Caleb McKinley and Lotte Sjulin.

This information will be used to help the University of Nebraska Medical Center (UNMC) admissions committee decide which aspects of an application to emphasize their focus on during selection of a matriculating dental class at the UNMC College of Dentistry. We hypothesize that DAT score, total science (TS), reading comprehension (RC), the female gender, and D1 GPA will all positively correlate with Final grade point average (GPA) and be statistically significant. We do not hypothesize that undergraduate GPA, age, military status, or parent in healthcare (P.I.H.) will correlate with Final GPA.

Our study was designed as a blind, retrospective study from the UNMC College of Dentistry graduating classes of 2015, 2016, 2017, 2018, and 2019. This totaled 231 eligible dental students over the 5 dental classes. Pearson correlation coefficients were calculated for associations between continuous variables (e.g. test scores, grades) and final GPA. Independent samples t-tests were used to assess for differences in mean final GPA between dichotomous groups (i.e. gender (male/female) or parent in health care). A Wilcoxon Rank Sum test was used to assess for a difference in the distribution of final GPA between students with or without a military background. A t-test was not used due to small sample size. A general linear model was used to assess differences in mean GPA between the various class years and used Tukey’s adjustment for p-values of post-hoc pairwise comparisons. A mixed effect model was used to determine model adjusted effects of multiple variables’ associations with final GPA and included random intercepts for class year.

The correlation between undergraduate GPA, PAT, and TS with final dental school GPA were statistically significant. The correlation between gender, military status, parent in healthcare, and reading comprehension with final dental school GPA were not statistically significant.

Contrary to what we originally hypothesized, by far the largest indication of dental school final GPA was undergraduate GPA. Followed by this, PAT score was the second most significant predictor of final dental school GPA. Lastly, Total Science score of DAT was the only remaining statistically significant factor correlating with dental school grades. Surprisingly, Reading and Comprehension DAT had no correlation with dental school GPA.

Dental Hygiene

1st Place - Elizabeth Dowling & Abigail Johnston, "Comparison of sodium fluoride dentifrice and nano-hydroxyapatite dentifrice in remineralization of carious lesions: An in vitro study." Mentor: Amanda Dolen 

Authors: Elizabeth Dowling and Abigail Johnston.

Study Purpose/Objective: In this study, researchers compared the remineralizing effects of an all-natural dentifrice containing nano-hydroxyapatite and a sodium fluoride natural dentifrice to that of a traditionally recommended dentifrice for remineralization that contains sodium fluoride.

Methods and Materials: The study was an in vitro study conducted on extracted, virgin, third molars that had sound enamel. The enamel of the specimens was demineralized by acid-etchant and then treated with the specific dentifrice depending on what group it belonged to. The Canary System was utilized to obtain demineralization and remineralization values.

Results: As hypothesized, no significant differences between the dentifrices were found.

Conclusion(s): The results suggest that nano-hydroxyapatite is as effective at remineralization of enamel as sodium fluoride.

2nd Place - Toni Doescher & Aspen Wallace, "Prevalence of dental hygienists performing extraoral and intraoral assessments in the state of Nebraska." Mentors: Lisa Moravec & Heather Hessheimer 

Authors: Toni Doescher and Aspen Wallace.

Study Purpose/Objective: To analyze the differences in extraoral and intraoral examinations (EO/IO examinations) between the University of Nebraska Medical Center (UNMC) Dental Hygiene program graduates to other dental hygiene program graduates who are currently practicing in the state of Nebraska.

Methods and Materials: The researchers purchased the Nebraska licensed dental hygienists list and sent a survey to all current hygienists. The survey was created through Survey Monkey and sent to the participants via email. After the three-week period, 94 responses were collected. The data was sent to the UNMC statistician for analysis.

Results: The statistician conducted an F-test to determine the quantitative responses between UNMC graduates to other program graduates. There was no significant evidence found between UNMC graduates in comparison to other program graduates. Dental hygienists are checking eight structures when performing IO examinations. Dental hygienists spend less than one minute performing EO examinations. There was no significant difference between UNMC graduates and other graduates in conducting IO examinations. The evidence shows UNMC graduates are spending significantly less time completing EO/IO examinations than other program graduates. The results showed the number of structures checked during EO examinations was not significantly associated to the program the respondents graduated from.

Conclusion(s): The researchers concluded UNMC graduates and other program graduates practicing in Nebraska are performing EO/IO examinations at routine appointments. No differences in EO/IO examinations were found when comparing the dental hygiene programs, the participants graduated from.

3rd Place - Abby Duffy & Emily Houtby, "A study of differing high-volume evacuator tips and their efficacy in removing aerosols." Mentor: Jaimee Shropshire 

Authors: Abby Duffy and Emily Houtby.

Study Purpose/Objective: The purpose of the study was to compare three vacuums (PureVac, Saliva Ejector and Nu-bird) in the elimination of aerosols produced during scaling.

Methods and Materials: Paper filter discs were used to collect the aerosol dispersion. Discs were placed at various orientations of 12,2,4,6,8, and 10 o’clock and at different distances of one, two and three feet. Scaling via the ultrasonic was done on three typodonts with two reps per typodont of each vacuum. Fluorescent dye was placed in the water to show visible representation of aerosol contamination on the paper discs. A clear grid was used to count each square centimeter of contamination on the discs.

Results: The data collected determined there was not a vacuum that overall did the best, but certain orientations and distances played a role in aerosol dispersion.

Conclusion(s): The data collected was inconclusive to show a definitive vacuum that reduced aerosols the most. However, the data suggested certain vacuums performed better in different orientations, while performing worse in others for all vacuums tested.


1st Place - Dr. Paul Pumilia, "The efficacy of an apex locator in detecting working length measurements in extracted teeth with the aid of the protrain device." Mentor: Dr. Hany Makkawy 

Authors: Drs. Paul Pumilia and Hany Makkawy.

Introduction: Most undergraduate preclinical endodontic courses utilize radiographs to identify working length distances on extracted teeth. The Protrain device fixates extracted teeth and allows students to use an apex locator to obtain working lengths. The purpose of this study is to evaluate the accuracy of an apex locator on extracted teeth while fixated in the Protrain device.

Methods: Thirty single rooted teeth were accessed and positioned in the Protrain device. Working length was then determined using the Root ZX II apex locator. After shaving the apical segment longitudinally with a diamond bur, the point of minor constriction was identified with a k file cemented in place. The distance from the constriction to the file tip was then found. Distances were summarized using medians and interquartile ranges. A Kruskal Wallace test was used to examine differences in distance between tooth groups (incisors, canines and premolars). Spearman correlations were used to assess relationships between distance and working length.

Results: All of the files were overextended past the point of minor constriction when viewed under a stereomicroscope. The mean length of overextension was 0.67mm. The median distance of overextension for the premolar group was 0.65 mm. The summary statistics for the incisor and canine groups were similar. There was no significant difference in distance between the tooth groups.

Conclusion: If used in a preclinical course, 0.67mm should be subtracted from the working length obtained when using the Protrain device with the Root ZX II but is a welcome addition to an endodontic armamentarium.

2nd Place - Drs. Devin Christiansen & Lauren Krell, "Effect of locally applied simvastatin on clinical attachment level and alveolar bone in periodontal maintenance patients." Mentors: Drs. Amy Killeen & Rick Reinhardt 

Authors: A. Killeen, R. Reinhardt, D. Christiansen and L. Krell.

The purpose of the study is to determine if local application of simvastatin is effective in increasing clinical attachment level (primary outcome), as well as alveolar bone (secondary outcome) compare to standard mechanical therapy in patients on periodontal maintenance therapy (PMT). Subjects undergoing PMT at the UNMC College of Dentistry and local private practice clinics will be recruited to participate in the randomized one year clinical trial based on the following eligibility criteria: 1) diagnosis of chronic advanced periodontitis (generalized or localized), 2) participating in regular PMT visits (3-6) month intervals, 3) no turnover (e.g. steroids, bisphosphonates, >325mg aspirin/day and in good general health). 4) One experimental quadrant of the mouth with an inflamed 6-9mm interproximal posterior periodontal pocket with history of bleeding on probing (BOP), 5) willingness to sign consent form. Subjects will be divided in two groups for additional therapy in a 6-9mm interproximal periodontal pocket at baseline: 1) local anesthesia and mini-flap reflection with subgingival mechanical debridement plus application of the simvastatin-methycellulose gel or 2) local anesthesia and mini-flap reflection with subgingival mechanical debridement plus application of the methcellulose gel only. Samples/measurements will be obtained at the designated experimental site at baseline (before treatment), 2 weeks, 6 and 12 months during PMT: 1) digital radiographs (baseline and 12 months only; bone height measurements), 2 ) presence of explorer-detectable supragingival plaque, 3) 30 second gingival crevicular fluid (GCF) sample (markers of inflammation, bone turnover), 4 recession from cemento-enamel junction, 5) probing pocket depth and bleeding on probing (BOP), 6) an approximately 2x2x2 mm piece of gingival connective tissue removed during baseline mini-flap and 2 week postoperative therapy (RT-PCR for gene activation). All patients will receive normal PMT at 3 and 9 months without measurements/samples.

Research Day Sponsors