Objectives: To compare two in-office bleaching methods with respect to tooth color change and level of hydrogen peroxide penetration into the pulp cavity, and evaluate relationships between penetration level and color change. Methods: 80 extracted canines were sectioned above the CEJ and pulp tissue removed. Tooth thickness was measured from the outer labial surface to the outer boundary of the pulp cavity at the cross-sectioned root 3mm below the CEJ using a digital caliper. Baseline color was measured spectrophotometrically; acetate buffer was added into the cavity. Teeth were mounted and exposed to two different bleaching regimens (conventional versus sealed bleaching technique). After exposure to 38% hydrogen peroxide gel for one hour, buffer was removed from the cavity and placed into a volumetric flask. Hydrogen peroxide amount was estimated spectrophotometrically using leucocrystal violet and horseradish peroxidase. Specimen color was re-measured 2 hours post-bleaching. Color change was measured per Commission Internationale de l'Eclairage methodology. Linear regression was used to evaluate factors affecting color change, including bleaching technique. Results: The conventional and sealed bleaching groups showed no difference at baseline with respect to tooth thickness or any of the L*a*b color measures (p>0.51); however there was significantly greater hydrogen peroxide penetration in the conventional bleaching group (p<0.0001). Linear modeling of the change in lightness (ΔL) showed that the increase in lightness tended to be greater for teeth with lower initial L* values (r=-0.32, p=0.004). After adjustment for initial L*, there was no evidence that ΔL differed with hydrogen penetration levels (p=0.53) or bleaching technique (mean group difference in ΔL= 0.36; p=0.27). Conclusion: Both groups showed significant increases in lightness exceeding 2 units and therefore discernible to the naked eye (p<0.0001); however, mean ΔL did not differ significantly with bleaching method or hydrogen peroxide penetration.

The objective of this work was to develop a short-term, clinically simulative, biofilm-based aging/storage model for lab testing of newer dental adhesives in order to predict their long-term performance. To do this we tested the hypothesis that 15 days of biofilm challenge with cariogenic bacterial species, Streptococcus mutans (SM) and Streptococcus sobrinus (SS), would produce similar or a greater reduction in microtensile bond strength (μTBS) of dental adhesives as compared to a standard 6 months of water storage (WS). Thirty-one molars were flattened to dentin, restored using Optibond-FL adhesive and Z-100 dental composite, sectioned and trimmed into four dumbbell-shaped specimens and randomly distributed according to aging conditions (n=31): A) Water storage for 6 months, B) Water storage for 5.5 months + S. mutans-biofilm challenge for 15 days, C) S. mutans-biofilm challenge for 15 days and D) S. sobrinus-biofilm challenge for 15 days. Specimens were gripped centrally with respect to the test axis with a non-gluing passive gripping device. Microtensile bond strength testing was performed using a Zwick Material Testing Machine at a crosshead speed of 1 mm/min and failure modes were classified using light microscopy. Mixed model ANOVA and Weibull regression analysis revealed that the type of storage condition significantly affected the microtensile bond strength (p<0.0001). Mean microtensile bond strength observed within group A (49.69 ± 15.53MPa) was significantly higher than those in groups B (19.26 ± 6.26MPa), C (19.92 ± 5.86MPa) and D (23.58 ± 7.88MPa). Also, microtensile bond strength obtained with group D was significantly greater than that with groups B and C, while no difference was seen between the latter two groups. Chi-square statistical analysis indicated that specimens from groups B (74.2%), C (83.9%) and D (80.6%) were more likely to have cohesive failures in dentin than specimens from group A (54.8%). Within the limitations of the study, it can be concluded that 15 days of Streptococcus mutans- and Streptococcus sobrinus- based biofilm challenge produced more reduction in microtensile bond strength of dental adhesive than 6 months of water storage and appear to be a promising in vitro accelerated aging model.

No description available.

Safety net clinics across the country struggle with a lack of resources to tackle the needs presented. Screening programs set up for children and elderly have proven to be effective in triaging need, prioritizing care, and maximizing resources. These programs do not currently exist for working uninsured adults. Research was initiated to answer the question: Does the screening process improve patient care for the community clinic? During a 6-week pilot study a licensed dental hygienist performed 30 screenings in the community clinic setting. Findings were recorded and coded according to patient’s level of need identified. Pre- and posttest data for patient care factors were attained. Statistical tests showed a significant effect on patient care factors. While the evidence existed to support the implementation of screening, more research would quantify the specific impact on this population.

Professional associations must have a significant level of membership to be effective. Georgia membership is increasingly low; therefore, ADHA cannot represent dental hygienists’ interests. This study determined factors that caused dental hygienists to continue to forgo membership in the ADHA. Several theoretical views of professional membership were considered. The sample was acquired from an unbiased systematic sampling of 50% (3,270) of registered dental hygienists and a convenience sampling of ADHA nonmembers at 2 continuing education seminars in Georgia. Data collection procedures included an electronic cover letter, consent form, and survey via Survey Monkey or hard copies for seminars. Three hundred sixteen participated yielded a 9.6% return rate. Participants were primarily women, holding associate degrees, and graduates of programs in Georgia. Participants worked full time in private practice, were satisfied with their working hours, and did not join GDHA because membership fee is too high or not sure of benefits offered. Twenty-one percent stated that lowering membership fee would entice them to join, and participants indicated they obtained their continuing education hours at the Hinman (52%) convention and online (27%).

AN INVESTIGATION OF SURFACE CHARACTERISTICS OF ENAMEL TREATED WITH INFILTRATIVE RESIN: A SCANNING ELECTRON MICROSCOPY STUDY Danielle E. Easterly, Doctorate of Dental Surgery. A thesis submitted in partial fulfillment of the requirements for the degree of Master of Science in Dentistry at Virginia Commonwealth University. Virginia Commonwealth University. 2017. Director: Dr. Eser Tüfekçi D.D.S., M.S., Ph.D., M.S.H.A. Objective: To evaluate the microstructural changes of a resin infiltrant (ICON®, DMG America LLC, Englewood, NJ) after six months of simulated toothbrushing. Materials and Methods: Ten extracted third molars (n=10) were collected. Artificial white spot lesions were created and resin applied. Environmental SEM images at 250X and 500X were taken after application of Icon® (T1), and after six months of simulated toothbrushing (T2). Micrographs were evaluated for changes in surface characteristics. Results: SEM showed some changes in the surface characteristics of the resin after simulated toothbrushing. However, changes in presence of enamel rods, microcracks, or fractures were not statistically significant (p>0.05). The effects of polymerization shrinkage were noted on most samples in the form of clefts and fissures. Conclusions: Icon® resin seems to withstand challenge by toothbrush abrasion over a six-month period, with some evidence of microstructural wear.

Oral health is strongly correlated to systemic health in the United States. Dental professionals play a significant role in addressing the oral health and prevention of disease for populations in the United States. Because many areas in the United States lack access to dental care, the federal government considers dental hygienists part of the solution. It is now paying attention to restrictive dental hygiene scope of practice rules in each state. State dental boards, comprised mainly of dentists, make these rules based on their perception of dental hygienists' lack of education. This study explored fourth-year dental students' perceptions of the dental hygienist's education and scope of practice. This research found that while dental students felt that the dental hygienist would be a positive addition to their future practices, they did not wholly understand the rigors of dental hygiene education. In addition, dental schools may need to educate on the differences between direct and general supervision.

Implementation of electronic health records by the Health Information Technology for Economic and Clinical Health has led to the implementation of electronic dental records (EDRs) and digital radiography in dental offices. The purpose of this study was to determine the state of the implementation and usage of EDRs and digital radiographs by the private general and pediatric dental practices in Mississippi as well as reasons why the dental practices are not moving forward with the advanced technology. A survey was emailed to 712 dental practices: 116 responded (16% response rate), and 104 consented to participate (89.66%). Results indicated dental practices in Mississippi using EDRs was 46.07%, EDRs with paper records was 42.70%, and only paper records was 11.24%. Results indicated dental practices using digital radiography was 76.40%, conventional radiography was 13.48%, and both was 10.11%. Common reasons for not advancing were cost, insufficient training, computer/software issues, and “too old.”

Aims Use of 3D printed models in Endodontics has been gaining popularity since the technology to create them became more affordable. Currently, there are no studies that evaluate the influence of 3D models on endodontic surgical treatment planning and on operator confidence. Therefore, aims of this study were to: (i) Determine whether the availability of a 3D printed analogue can influence treatment-planning and operator confidence; and, (ii) Assess which factors of operator confidence are influenced, if any. Materials and Methods Endodontists were asked to analyze a pre-selected CBCT scan of an endodontic surgical case and to answer a questionnaire that determined their surgical approach for that case. After 30 days, the same participants were asked to analyze again the same CBCT scan. This time however, a 3D printed model of the scan was made available to the participants and to perform a mock osteotomy on the model. The participants were then asked to respond to the same questionnaire that they responded to 30 days prior to determine if there would be any changes to their treatment plan. A new set of questions were added to the survey to evaluate the influence of the 3D printed model on participants’ confidence in performing endodontic surgery. The responses were statistically analyzed using Chi square test followed by either logistic or ordered regression analysis while adjusting for experience of participant. Adjustment for multiple comparison analysis was done using Bonferroni correction. Statistical significance was set at £0.005. Results Availability of the 3D printed model and the CBCT scan together resulted in statistically significant differences in the participants’ responses to their ability to clearly detect bone landmarks, accurately predict the location of osteotomy, and in determining the following: size of osteotomy, angle of instrumentation, involvement of critical structures in flap reflection and involvement of vital structures during curettage. In addition, the participants’ confidence in performing surgery was significantly higher versus having CBCT scans alone. There were no statistically significant changes with decisions on flap design and extent, visualizing critical structures, lesion size, injury to vital structures during osteotomy, the length of root that could be resected and the number of roots involved. Conclusions The availability of 3D printed models did not alter the participants’ surgical approach, but it significantly improved their confidence for endodontic microsurgery, which can be attributed to better visualization of anatomical structures.