A Classroom Practice and Assessment Resource for Dental Clinical Treatment Planning.

Introduction: Dental students' opportunities to practice clinical treatment planning prior to the clinical experience are often limited. This resource permits students to practice treatment planning in the classroom and allows the instructor to efficiently provide feedback to a large number of students. Methods: I developed a computer-based treatment plan worksheet (Microsoft Excel, Google Sheets, or Qualtrics) consisting of four sequence steps and a list of Common Dental Terminology (CDT) codes. I implemented this educational activity in the Case Management and Treatment Planning course (second year, spring quarter). The course included 10 weekly sessions of 1 hour each. I gave students a practice case at the beginning of the course. They submitted comprehensive sequenced treatment plans as assignments using the Qualtrics treatment plan worksheet 2 days after the interdisciplinary treatment planning didactic session. In the subsequent debrief session, I discussed the case with the entire class and focused on themes observed from the students' performance on the assignments. Results: I graded all students' submissions (n = 87) using CDT codes both with and without consideration of sequence steps and observed variations in students' performance. Many students (n = 36, 41%) opted to give feedback through an anonymous survey, with 88%-96% of them agreeing or strongly agreeing that the educational activity allowed them to practice, demonstrate their knowledge, and improve their skills in treatment planning. Discussion: This computer-based worksheet lets students practice clinical treatment planning in the classroom and allows the instructor to effectively assess a large number of students' assignments.

Phosphoric Acid Etch Partially Restores the Initial Bond Strength of Composite to Silver Diamine Fluoride-Treated Enamel Using Universal Adhesives.

BACKGROUND: Restoring bonding composite to silver diamine fluoride (SDF)-treated enamel is challenging. This study investigates if phosphoric acid etch restores composite bond strength to SDF-treated enamel using universal adhesives. METHODS: Twenty-four recently extracted permanent teeth were randomly divided into 4 (2 experimental (SDF) and 2 control (CTR)) groups: SDF+Water: SDF (1 min) then water rinse (15 mL); CTR+Water: no treatment and water rinse (15 mL); SDF+Etch+Water: SDF (1 min), 35% phosphoric acid (40 s) then water rinse (15 mL); CTR+Etch+Water no treatment, 35% phosphoric acid (40 s) then water rinse (15 mL). The enamel surface in all the groups was bonded (All-Bond Universal) to 4-5 mm composite blocks (Z-250). Each sample was sectioned, and 6-8 beams (1 mm × 1 mm) were selected. The micro-tensile bond strength was measured by dividing the micro-tensile force peak by the adhesive surface area. Univariate ANOVA and Chi-square were used for between-group comparisons with p < 0.05. RESULTS: SDF+Water had significantly lower tensile strength compared to all the groups (p < 0.05). Although no difference was found in the tensile strength between the SDF+Etch+Water and the CTR+Etch+Water, the SDF+Etch+Water had significantly more adhesive failures compared to the CTR+Etch+Water (p = 0.047). CONCLUSIONS: While phosphoric acid etch seems to restore the initial composite bond strength to SDF-treated enamel, the long-term success of composite restorations bonded to SDF-treated enamel may need further investigation.

Can students develop clinical competency in treatment planning remotely through flipped collaborative case discussion?

INTRODUCTION: Effectiveness of flipped learning in clinical education is unknown. This study evaluates the effectiveness of remote case-based learning for teaching clinical treatment planning compared with traditional in-person clinical experience. MATERIALS AND METHODS: Four cases containing medical and dental charts were discussed through flipped learning with faculty panel during the COVID-19 lockdown. Prior to each session, students worked individually or in groups to complete assignments with leading questions. After the final assignment, students completed a survey to rate the learning experience from each case, compare the remote experience with the previous in-person clinical experience and provide suggestions to improve remote clinical instruction in the future. Students' performance measured by the number of case assessments and competencies completed post-lockdown was compared with pre-lockdown and the previous year using odd ratio (OR), Chi-squared test (χ2) and significant level p < .05. RESULTS: A total of 106 students completed the course, and 99 students completed all survey questions. Students reported positive learning experiences (overall mean = 7.84, SD = 1.11). Post-lockdown, statistically significant increase in the proportions of total passed attempts (χ2 p = .002, OR = 2.23), competencies (χ2 p = .028, OR = 2.05) and case assessments (χ2 p = .004, OR = 2.73) was observed between the current class and the previous pre-COVID-19 class (108 students). Post-lockdown, students also passed significantly more attempts (χ2 p < .0001), competencies (χ2 p < .0001) and case assessments (χ2 p = .008) compared with pre-lockdown. CONCLUSIONS: Although a flipped classroom does not replace in-person clinical experience, teaching clinical treatment planning remotely improved students' readiness and clinical performance through collaborative learning, practice and case exposure.

Radiographic Changes to Silver Diamine Fluoride Treated Carious Lesions after a Rinsing Step.

Silver diamine fluoride (SDF) is radiopaque. This in vitro study compares the changes in the radiopacity of carious lesions after SDF application, potassium iodide (PI) application, and water rinse. Ten recently extracted human teeth were sectioned and divided into two groups (n = 10 in each group): Group 1 = SDF, Group 2 = SDF + PI. Teeth in Group 1 received SDF for 1 min and rinsed with 15 mL water. Group 2 received the same protocol with the addition of PI application for 1 min after SDF application. All samples were scanned with micro-computed tomography before SDF application, after SDF application, after PI application (group 2) and after water rinse. The radiopacity of the carious lesions increased significantly after SDF application in Group 1 and 2 (p < 0.017, p < 0.008, respectively). A significant increase in radiopacity after PI application was also observed in Group 2 (p < 0.008). Water rinsing significantly decreased the radiopacity in Group 1 and 2 (p < 0.017, p < 0.008, respectively), but the radiopacity remained significantly higher than the preoperative values (Group 1 p < 0.017, Group 2 p < 0.008). The radiopacity of carious lesions increases after SDF and SDF + PI applications. Water rinsing could reduce the radiopacity of SDF and SDF + PI treated carious lesions, and might reduce the content of SDF in carious lesions.

Profile of bacteria colonizing the exposed bone of patients with anti-osteoclastic drug-related osteonecrosis of the jaws.

Microbial etiology for anti-osteoclastic drug-related osteonecrosis of the jaw (ARONJ) was suggested. This study investigates any link between bacteria colonizing ARONJ sites and other oral cavity sites. Microbiota samples of 10 ARONJ patients were collected from the exposed bone, adjacent teeth, contralateral teeth, and tongue. DNA checkerboard hybridization was used for microbiota analysis with 43 genomic DNA probes prepared from human oral bacterial (38) and candida (5) species, using Socransky's bacterial complexes as a guide. The frequency and the mean proportion of each bacterial species were used. Eikenella corrodens, Streptococcus constellatus, and Fusobacterium nucleatum were dominant in the ARONJ sites and detected in most teeth samples. Staphylococcus aureus was also dominant in the ARONJ sites and tongue. Significant correlations were found between the mean proportions of bacterial species colonizing adjacent teeth, contralateral teeth, and tongue (p < 0.001, R(2) > 0.69). No significant correlation (p > 0.05, R(2) < 0.025) was found between bacteria colonizing ARONJ sites and other evaluated sites. Within the study limitations, it was concluded that the primary sources of microorganisms colonizing ARONJ sites could be other sites such as teeth and tongue. The microbial profile of the necrotic bone is predominantly colonized with bacteria from Socransky's green and orange complexes, as well as with species associated with bone infections.

Bisphosphonates inhibit bone remodeling in the jaw bones of rats and delay healing following tooth extractions.

OBJECTIVE: This study aimed to evaluate the impact of concurrent administration of clinically relevant doses of zoledronic acid (ZA) and dexamethasone (DX) on bone healing after tooth extraction (EXO). MATERIALS AND METHODS: Forty-four Sprague-Dawley rats (6-8 month old) were randomized into five groups: ZA + DX = weekly injection of ZA with DX for 7 weeks; WD = ZA with DX for 3 weeks then DX alone for 4 weeks; C = control saline for 7 weeks; ZA = ZA alone for 7 weeks and DX = DX alone for 7 weeks. ZA was administered at 0.13 mg/kg/week and DX at 3.8 mg/kg/week and body weights recorded at the time of injection. All rats underwent extraction (EXO) of the mandibular and maxillary first molars at 3 weeks and were euthanized at 7 weeks. The extracted and non-extracted sides of both jaws were harvested for micro-CT analyses. RESULTS: All rats, particularly those injected with ZA, exhibited weight gain till EXO followed by decline then recovery. ZA + DX group demonstrated highest fractional bone to tissue volume (BV/TV) in the non-extracted side. ZA + DX rats exhibited also highest volume and surface of sequestra. Only sequestra volume was statistically higher in the WD group compared to C group. CONCLUSION: Combined treatment with ZA and DX over a prolonged period inhibits bone remodeling and increased sequestra formation to a greater extent than either drug alone. Trauma caused by these sequestra cutting through the mucosa could play a key role in the development of BRONJ by potentially facilitating infection. ZA withdrawal may promote bone-remodeling reactivation following EXO.

Effect of implant angulation on attachment retention in mandibular two-implant overdentures: a clinical study.

PURPOSE: Attachment wear can affect the performance of mandibular two-implant overdentures (IODs). This prospective clinical study aimed to investigate the effect of interimplant angulation on the retention achieved by two attachment systems at different time points within 1 year of wearing IODs. MATERIALS AND METHODS: Twenty-four patients (mean age = 73.2 years; standard deviation (SD) = 3.1) wearing IODs opposed by conventional maxillary complete dentures were randomly assigned to two groups in two-by-two crossover design. Retentive Anchor (RA) and Locator (LA) were installed in the IODs of both groups for 1 year, sequentially. Coronal and sagittal interimplant angulation were measured on posterior-anterior and lateral cephalometric radiographs. Retention was measured at baseline, 1 week, 3, 6, and 12 months postattachment installation. Data were analyzed using mixed models with α = 0.05. RESULTS: Mean coronal and sagittal interimplant angulations were 4.6 (SD = 2.9) and 3.5 (SD = 2.6) degrees, respectively. Only with LAs a statistically significant decrease was found in retention (average 1.1 Newton; standard error = 0.38; p = .007) per 1 degree increased sagittal interimplant angulation. CONCLUSIONS: Increased interimplant angulation appears to have higher impact on the retention of LA than of RA attachments. The effect of larger interimplant angulation on the loss of attachment retention and its clinical implications should be further assessed.

Assessing the oral microbiota of healthy and alcohol-treated rats using whole-genome DNA probes from human bacteria.

OBJECTIVE: This study aimed to evaluate the capacity of whole-genome DNA probes prepared from human oral bacteria to cross-react with bacteria from the oral cavity of rats, and to assess the influence of alcohol ingestion on the animals' oral biofilm. DESIGN: Twenty four mature Wistar rats were equally divided in two groups. One group (control) was fed balanced diet of rat pellets and water. The alcohol-treated group (AT) received the same diet and 20% ethanol solution. Upon euthanasia after 30 days, bacterial samples from the oral biofilm covering the animals' teeth were collected using microbrushes. Bacteria identification and quantification were performed using the DNA checkerboard hybridization method with 33 probes prepared from human oral bacteria. Signals corresponding to bacterial genome counts and percentages were compared using a Mann-Whitney U test with a significance level <0.05. RESULTS: Cross-reaction for all targeted species, except Streptococcus mutans and Streptococcus mitis-like species, occurred in the control group. Escherichia coli, Pseudomonas aeruginosa, Porphyromonas endodontalis, and Veillonella parvula-like species only produced detectable signals in the AT group. Significantly more signals were detected in the control group compared to the AT group (p=0.001). The percentage of E. coli-like species was highest in both groups. CONCLUSIONS: Whole-genome DNA probes prepared from human oral bacteria can cross-react with rats' oral bacterial species. Alcohol consumption is associated with lower levels and diversity of bacterial species in the oral cavity of rats.