Accuracy of impression scan bodies for complete arch fixed implant-supported restorations.

STATEMENT OF PROBLEM: Despite the extensive studies on and comparisons of different implant impression techniques for completely edentulous patients, studies on novel techniques that combine conventional impression making with digital scanning are lacking. PURPOSE: The primary aim of this study was to compare the accuracy of the impression scan body technique with conventional impression making and digital scanning for a completely edentulous mandibular arch. The secondary aim was to assess the relationship between different implant angulations and interimplant distances in relation to the recording accuracy. MATERIAL AND METHODS: An edentulous mandibular definitive cast (control) was designed with 5 implants placed at different angles and interimplant distances. Three recording techniques were tested: a conventional impression with splinted copings (conventional) (n=15), an impression scan body technique where impression scan bodies were attached to the splinted impression copings in a conventional elastomeric impression and then digitally scanned with an extraoral scanner (n=15), and an intraoral digital scanning technique (digital) (n=15). For comparison, the definitive cast and the conventional impression stone casts were digitized into standard tessellation language (STL) datasets using the extraoral scanner. The 3-dimensional (3D) deviations between the 3 test groups and the control were calculated by superimposing the STL datasets. The 3D deviations from the control were compared by using the Kruskal-Wallis test followed by the Dunn post hoc test (α=.05). The Mann-Whitney test was used to investigate the effect of implant angulation and interimplant distance on impression accuracy (α=.05). RESULTS: The conventional splinted-coping impression technique showed a mean 3D deviation of 0.408 mm. The impression scan body and intraoral digital scan showed similar mean 3D deviations, 0.219 mm and 0.257 mm, respectively (P=.334). Both techniques showed significantly lower 3D deviations than the conventional technique (P<.001). Implants at an angle of 5 degrees and 10 degrees showed a statistically significant difference (P=.010) with mean 3D deviations of 0.340 mm and 0.396 mm, respectively. Implants with 5-mm and 10-mm interimplant distance showed a significant difference (P<.001) with mean 3D deviations of 0.301 mm and 0.423 mm, respectively. CONCLUSIONS: The impression scan body technique is comparable with intraoral digital scanning for a completely edentulous arch. Increased implant angulation and increased interimplant distance significantly reduced the accuracy of implant impression making or scanning.

Cognitive impairment and edentulism among older adults: an observational study using claims data.

BACKGROUND: The scientific link between mastication strength and cognitive function has not yet been strongly corroborated in population studies. Utilizing large-scale claims, we aim to investigate the association between edentulism and cognitive impairment in older American adults. METHODS: Using de-identified claims from a commercial insurer from 2015-2019, we conducted a retrospective cohort study using multilevel regression models to evaluate the association between denture status and clinically diagnosed cognitive impairment. Secondary analysis included symptomatic cognitive impairment in the outcome. RESULTS: Adjusting for individual-level risk factors, denture status was significantly associated with clinical cognitive impairment with odds ratios of 1.13 (95%CI: 1.02-1.25) and 1.26, (95%CI: 1.09-1.45) for complete dentures on one or both jaws, respectively. Including symptomatic cognitive impairment in the analysis did not substantially change our fundamental findings. CONCLUSION: Prevention and treatment of oral diseases should be considered a key component in preserving the overall wellness of older adults.

Efficacy of bisphosphonates in detection of early enamel caries using NIR fluorescence imaging and inhibition of caries progression.

NIR fluorescence imaging using bisphosphonate-Indocyanine green has been indicated for early interproximal caries detection. This study assessed diagnostic accuracy of caries detection by NIR fluorescence imaging with OsteoSense 750® (OS750) in vitro and ex vivo, and to analyze the therapeutic efficacy of a bisphosphonate (Etidronate) in inhibiting enamel caries progression in vitro. Methods: Four experiments were conducted using extracted human teeth; 1) to calculate the infiltration rate of OS750 into interproximal white spot lesions using fluorescence microscope, 2) to assess diagnostic accuracy of interproximal natural white spot lesions using desktop NIR fluorescence imaging device in vitro setting, 3) to assess diagnostic accuracy of artificially created deeper enamel carious lesion (0.5 mm~1.0 mm) using NIR fluorescence image through the head-mount display in ex vivo setting, 4) to compare the progression on the enamel caries lesions treated by Etidronate, NaF and distilled-water. Diagnostic accuracy was analyzed using sensitivity, specificity and receiver operating curves (ROC). The caries progression was calculated with micro-CT and was statistically analyzed using a two-way ANOVA and the Tukey HDS post-hoc test. Results: 1) The infiltration rate of OS750 was 101.83% ± 8.66 (Min: 90.10%, Max: 133.94%). 2) The average of sensitivity and specificity in vitro setting experiments were 86.7% ± 4.4% and 70% ± 11%, respectively. The average of area under the ROC curves (AUC) was 0.883 ± 0.059 indicating excellent performance. 3) The mean sensitivity and specificity in ex vivo setting was 82.97% ± 15% and 76.78% ± 13.27% respectively. 4) The carious lesion volume treated by Etidronate was significantly smaller at post treatment-1 (p<0.05) and treatment-2 (p<0.01) than the control. There was no significant difference in lesion volume in the Etidronate and NaF group at the time point of post treatment-1. Conclusion: This study suggests that bisphosphonates contribute to both early diagnosis of enamel caries and inhibition of caries progression.

Establishment of perpendicular protrusion of type I collagen on TiO2 nanotube surface as a priming site of peri-implant connective fibers.

Natural teeth are supported by connective tissue collagen fibers that insert perpendicularly in the tooth cementum. Perpendicular insertion plays an important role in the maintenance of the junction between the oral epithelium and the periodontal connective tissue. Most titanium dental implant surfaces have no micro or macro structure to support perpendicularly oriented collagen attachment. Without this tight biologic seal to resist bacterial invasion and epithelial downgrowth, progressive bone loss in peri-implantitis is seen around dental implants. The purpose of this study was to establish the perpendicularly oriented collagen attachment to titanium oxide nanotube (TNT), and to assess its binding stability. TNT was prepared on the titanium-surface by anodization. Scanning electron microscopy (SEM) showed a regularly aligned TNT with an average 67 nm-diameter when anodized at 30 V for 3 h. Subsequently, collagen type I (CoI) was electrophoretically fused to anodic TNT in native polyacrylamide gel system where negatively charged CoI-C term was perpendicularly navigated to TNT. SEM and atomic force microscopy (AFM) were used to analyze CoI on the TiO2 and TNT surface. Several tens of nanometers of CoI protrusion were recorded by AFM. These protrusions may be long enough to be priming sites for cell-secreted CoI. CoI laid parallel to the titanium surface when fused by a chemical linker. Binding resistance of CoI against drastic ultrasonication was measured by Fourier-transform infrared spectroscopy attenuated total reflection (FTIR-ATR). The electrophoretically fused CoI in the titanium nanotube (TNT-CoIEPF) showed the significantly greatest binding resistance than the other groups (P < 0.01, a 1-way ANOVA and Tukey HSD post hoc test). Furthermore, TNT-CoIEPF surface rejected epithelial cell stretching and epithelial sheet formation. Chemically linked horizontal CoI on titanium oxide (TiO2) facilitated epithelial cell stretching and sheet formation.

Knowledge and Practice of Oral Cancer Screening in Teaching Faculty-Comparison of Specialty and Year of Clinical Experience.

The purpose of this study was to assess the knowledge, practice, confidence, and perceived barriers to oral cancer screening among teaching faculty in Japan. Results were compared by specialist as well as years of clinical experience. A 25-question survey was used to assess the oral cancer screening practices of faculty dentists at Iwate Medical University, School of Dental Medicine, the only dental school located in the northeast (Tohoku) region of Japan. The study was approved by the Institutional Review Board of Iwate Medical University. The response rate was 83% (n = 110, 71.8% were male). This survey revealed that only 43.6% of the dentists performed oral cancer screening frequently (always or usually) at the initial appointment, and there was no significant differences between specialists and clinical experience. Visual inspection of the oral cavity was the primary screening method, but the frequency and content of the examination (TMJ and tonsil) was significantly different between specialties. A history of cancer and tobacco use motivated providers to perform an examination and was significantly different between various specialists and clinically experienced providers. In contrast, HPV and alcohol consumption were a weak motivator. The confidence level of providers on their examination knowledge/skills was poor, especially among junior faculty. More than 80% of junior faculty indicated a lack of knowledge/skills as a major barrier.

A prospective clinical trial to assess the optical efficacy of pink neck implants and pink abutments on soft tissue esthetics.

OBJECTIVE: The purpose of this prospective, randomized, controlled, multicenter clinical study was to analyze the optical effects of an anodized pink colored implant shoulder/abutment system in the peri-implant mucosa of immediately placed dental implants. MATERIALS AND METHOD: Forty subjects with a restoratively hopeless tooth in the maxillary esthetic zone, were recruited and randomized to receive either a pink-neck implant, or a conventional gray implant. All patients received an immediate implant and immediate provisional and two identical CAD/CAM titanium abutments with different surface colors: pink and gray, and one zirconia all-ceramic crown. The color of the peri-implant mucosa was measured using a dental spectrophotometer and analyzed using CIELAB color system. RESULTS: The overall color difference between the peri-implant mucosa with a pink abutment and a gray abutment was ΔE = 4.22. Patients with gray implants presented a color change of ΔE = 3.86-4.17 with this abutment change, while patients with pink implants had a color change of ΔE = 3.84-4.69. The peri-implant mucosa with a pink abutment was significantly more red when compared with a gray abutment (P ≤ .01). CONCLUSIONS: When a pink abutment was used, there is a significant color change of the peri-implant mucosa that is above the detectable color threshold. CLINICAL SIGNIFICANCE: Esthetic outcomes are important for the success of implant treatment of maxillary anterior implants. The phenomenon of the gray color of a dental implant and abutment shining through the peri-implant mucosa has been documented in the literature. The objective of this study was to assess the optical effect of an anodized pink-neck implant and a pink abutment on the color of peri-implant mucosa. This study demonstrates that using pink-neck implant and a pink abutment would contribute positively to the overall esthetic outcome for an anterior implant.

The Effect of a Toothbrush Handle Design in Combating Microbial Contamination.

OBJECTIVES: This study aims to assess the difference in microbial contamination of a toothbrush with a smooth handle versus a toothbrush with a grooved handle design. METHODS: Twenty-six volunteers were randomized into two groups. The first group used a smooth handle toothbrush for two months, followed by a grooved handle toothbrush for two months. The second group had the order reversed. Following the two-month use, the toothbrushes were submitted for microbial analysis. Effect size, as well as Wilcoxon signed-rank test were used to calculate the differences between total colony count, bacterial DNA, and endotoxin levels from the two toothbrush handle types. RESULTS: There was no significant difference in colony count between the smooth (mean 580 CFU/mL, SD 1,684 CFU/mL) and grooved (mean 19,059 CFU/mL, SD 80,972 CFU/mL) handles (p = 0.12). Total DNA count was significantly less (p = 0.01) on the smooth handle (mean 68,038 RFU/mL, SD 81,659) compared to the grooved handle (mean 209,312 RFU/mL, SD 257,169 RFU/mL). Endotoxin levels were significantly less (p = 0.01) on the smooth handle (mean 0.16 EU/mL, SD 0.30 EU/mL) compared to the grooved handle (mean 0.43 EU/mL, SD 0.49 EU/mL). CONCLUSIONS: The smooth handle toothbrush had significantly less bacterial contamination compared to the grooved handle toothbrush, as measured by total DNA count and endotoxin levels.

Identification of putative bone anabolic peptides targeting adherent plasma membrane.

Bone matrix provides unknown essential cues for osteoblast lineage cells to develop, grow, repair and remodel bones via adherent plasma membrane. Because of its tight sealing with bone matrix in vivo and culture surface in vitro as well, the adherent plasma membrane has been unveiled target of investigation to date. Herein, we report a new approach to explore the adherence plasma membrane of osteoblasts with biofunctional peptide candidates in a bacterial peptide library. To accomplish this, human osteoblast like hFOB 1.19 cells were cultured on porous filter with 8 µm pore through which bacterial peptides were allowed to meet the membrane for affinity selection. The affinity-selected peptides were coated on culture plate to further evaluate their influence on osteoblastic cell adhesion, as well as expressions of osteoblast differentiation markers, alkaline phosphatase and osteocalcin. Finally, the serial screenings identified two prominent active peptides that enhanced the differentiation markers nearly to the same level as a control peptide of bone morphogenetic protein-2. Osteogenic activity is expected for the peptides when immobilized on bone implant surface.

Assessing the accuracy of computer color matching with a new dental porcelain shade system.

STATEMENT OF PROBLEM: In a previous study, a novel computer color matching system for dental ceramic restoration was developed, and 21 new shades were established. Theoretically, a natural tooth color can be accurately reproduced by combining 2 or 3 ceramic mixtures from the database of 21 new shades. PURPOSE: The purpose of this study was to test the use of these shades in conjunction with the computer color matching system to determine their ability to accurately reproduce the body color of 29 shade tabs from a shade guide (VITAPAN 3D-Master). MATERIAL AND METHODS: Disks of 21 reference shades were prepared with porcelain (Cerabien CZR) and polished to 1.0 mm thickness. A spectrophotometer was used to measure the reflectance values from 380 to 780 nm for each disk; the scattering coefficient and absorption coefficient were determined. By using the reflectance values and the scattering and absorption coefficients, the computer color matching program generated porcelain prescriptions incorporating proportions from the 21 reference shades to reproduce the shade tabs. Disks were fabricated from the prescriptions, polished to 1.0 mm thickness, then placed over a zirconia core plate and measured with the spectrophotometer. The color differences (ΔE*) between the shade tabs and the corresponding ceramic disks were calculated. Statistical analysis was performed with the 1-sample t test. RESULTS: The ΔE* values between computer color matching specimens and the target shade tabs varied from 0.5 to 1.9, with an average ΔE* of 1.3, which was significantly less than the clinically detectable ΔE* threshold of 1.6 (P<.001). CONCLUSIONS: The computer color matching system with the established 21 new shades is accurate and effective for reproducing tooth shades.

Microscopic in-situ analysis of the mucosal healing around implants treated by protease activated receptor 4-agonist peptide or perpendicularly protruded type I collagen in rats.

Enhanced mucosal sealing around titanium implants can reduce complications such as peri-implantitis. The present study aims to investigate the mucosal healing at the early stage around the protease activated receptor 4-agonist peptide (PAR4-AP)- or perpendicularly protruded type I collagen (pCol)-treated titanium implants. A total of 72 implants were placed in 36 rats in the study. Following extractions, two tissue-level implants among the following three different surfaces, PAR4-AP-coated (PAR4 group, n = 24), pCol-treated (pCol group, n = 24) and non-treated (control group, n = 24) ones, were placed in the maxillae of each rat based on a split-mouth design. The specimens retrieved at 8 h (n = 8 per group), 3 days (n = 8 per group), and 2 weeks (n = 8 per group), were immunostained and tissue-cleared, and the signals of laminin-5 and collagen fibers were observed under multiphoton microscopy. Statistical analyses were performed using linear mixed model with post hoc tests to compare differences between the groups. While there was no intergroup difference at 8 h, the laminin-5 at 3 days was more abundant near the PAR4-group-surface, and its area was significantly larger in the PAR4 group (0.0204 ± 0.0194 mm2 ) than the control (0.0019 ± 0.0025 mm2 , p = .001) and pCol (0.0023 ± 0.0022 mm2 , p < .001) groups. The pCol group showed a significantly larger area of collagen fibers (0.0230 ± 0.0148 mm2 ) compared to the control (0.0035 ± 0.0051 mm2 , p = .002) and PAR4 (0.0031 ± 0.0057 mm2 , p < .001) groups at 3 days. At 3 days and 2 weeks, the collagen fiber orientation of the pCol group showed a more perpendicular manner compared to the control and PAR4 groups. The signal of basal lamina and collagen fibers were stronger around the PAR4-AP- and pCol-treated titanium surfaces, respectively during the early healing stage. This could have implications for improved mucosal sealing around dental implants, potentially reducing complications such as peri-implantitis.

Color effects of gingiva on cervical regions of all-ceramic crowns.

STATEMENT OF PROBLEM: The final color of all-ceramic crowns is influenced by the color of both the remaining tooth structure and the surrounding gingival tissue. The optical effects of gingival tissue on an all-ceramic crown have never been fully studied. PURPOSE: The purpose of this study is to investigate the effects of gingival color on ceramic crowns in the cervical region. materials and methods: Thirty-one all-ceramic crowns of differing shades were included in this study. Using a spectrophotometer, the color values of each crown were measured on a typodont in the absence of an artificial gingiva (control group) and in the presence of an artificial gingiva (test group). CIELAB color coordinates (L*, a*, b*) were collected from three regions of the cervical area in descending order from the gingival margin (upper region, middle region, and lower region). Color difference values (ΔE*) were calculated for each cervical region between the test and control groups. ΔE* between the test and control groups from the upper to lower cervical regions was also compared with each other. The statistical analysis was performed using the student t-test and one-way analysis of variance (ANOVA) test. RESULTS: The mean ΔE* values between the test group and control group at the upper, middle, and lower cervical regions were 5.8, 2.8, and 1.8, respectively. Significant color differences between the test and control group were detected in all three incremental regions (p < 0.001 at ΔE* = 1.6 threshold), with all color coordinates (L*, a*, and b*) contributing significantly to the color differences in these regions (p < 0.001). The color variations in the cervical area also varied significantly from the upper region to the lower region, with L* and a* contributing most to the differences. CONCLUSIONS: The presence of artificial gingiva is a critical factor in precise color matching and color reproduction for all-ceramic crowns. CLINICAL SIGNIFICANCE: Gingival tissue has significant optical effects on the color of all-ceramic crowns at the cervical areas; therefore, it is suggested that artificial gingiva be used by both dentists and ceramists while matching and replicating tooth color with ceramic restorations. (J Esthet Restor Dent ••:••-••, 2012).

Classification of Maxillofacial Morphology by Artificial Intelligence Using Cephalometric Analysis Measurements.

The characteristics of maxillofacial morphology play a major role in orthodontic diagnosis and treatment planning. While Sassouni's classification scheme outlines different categories of maxillofacial morphology, there is no standardized approach to assigning these classifications to patients. This study aimed to create an artificial intelligence (AI) model that uses cephalometric analysis measurements to accurately classify maxillofacial morphology, allowing for the standardization of maxillofacial morphology classification. This study used the initial cephalograms of 220 patients aged 18 years or older. Three orthodontists classified the maxillofacial morphologies of 220 patients using eight measurements as the accurate classification. Using these eight cephalometric measurement points and the subject's gender as input features, a random forest classifier from the Python sci-kit learning package was trained and tested with a k-fold split of five to determine orthodontic classification; distinct models were created for horizontal-only, vertical-only, and combined maxillofacial morphology classification. The accuracy of the combined facial classification was 0.823 ± 0.060; for anteroposterior-only classification, the accuracy was 0.986 ± 0.011; and for the vertical-only classification, the accuracy was 0.850 ± 0.037. ANB angle had the greatest feature importance at 0.3519. The AI model created in this study accurately classified maxillofacial morphology, but it can be further improved with more learning data input.

The Guided Bone Regeneration of a Large, Non-Contained, Perforated Maxillary Anterior Perforation Defect: A Case Report.

The reconstruction of alveolar ridge defects can be challenging, especially when the lesion is large, non-contained, and located in the esthetic region. The present report describes the guided bone regeneration (GBR) procedure and prosthetic rehabilitation of a severe perforation defect in the anterior maxilla. Clinical and radiographic evaluation of the lesion indicated an endodontic-periodontal origin, and biopsy results confirmed the absence of malignancy. GBR was performed with the use of cortical mineralized freeze-dried bone allograft (FDBA) combined with recombinant human platelet derived growth factor BB (rhPDGF-BB) and a resorbable collagen membrane without the use of tenting or fixation screws. At six months post-GBR, cone beam computed tomography (CBCT) revealed adequate bone fill for the placement of 4.1 x 10 mm or 4.1 x 12 mm dental implants. The implant surgery was fully guided with a two-stage approach. After a ten-month of healing phase, the implants were loaded with a screw-retained porcelain bridge. The staged GBR approach using a combination of FDBA, rhPDGF-BB, and a resorbable membrane without the use of tenting or fixation screws resulted in significant bone fill, successful implant placement, and a functional and esthetic implant-supported prosthesis.

Establishment of Biomimetic Soft Tissue Integration with the Surface of Zirconia Fused with Platelet-Activating Peptide.

Soft tissue sealing around zirconia (ZrO2) abutment is critical for the long-term stability of dental implants. The goal of the study is to develop a strong basal lamina (BL)-mediated epithelial attachment to ZrO2 via a novel physicochemical immobilization method. An electrophoretic fusion (EPF) method was applied to fuse a phosphonic acid (PA) linker to ZrO2 discs. Bindings of the PA linker and the following protease activated receptor 4 (PAR4) were verified by Fourier-transform infrared spectroscopy (FITR). Then, ZrO2 discs were doped in platelet-rich plasma (PRP). Platelet-derived growth factor (PDGF) was measured to assess platelet activation. PRP-doped discs were subsequently co-cultured with human gingival epithelial cells (OBA9) to evaluate establishment of basal lamina-mediated epithelial attachment. The EPF method achieved robust immobilization of the PA linker and PAR4 onto the ZrO2 surface. The resultant PAR4-coupled ZrO2 successfully induced platelet aggregation and activation. Furthermore, a BL-mediated epithelial attachment was established. The results are significant for clinical application to minimize the risk of developing peri-implant diseases.

A cross-sectional survey of patient's perception and knowledge of dental implants in Japan.

BACKGROUND: This study aimed to collect data regarding patient perception and knowledge of dental implants. It was conducted with the hope that the data would provide dental professionals and policymakers with a better understanding of ways to promote implant therapy. METHODS: An anonymous online survey with 10 questions was distributed through 12 dental offices in Tokyo and provincial cities in Japan to assess patient perception and knowledge of dental implants. Harvard Medical School's IRB approved this study. RESULTS: We collected data from 1172 patients (59% female, 41% male). The most common perceptions of implant therapy were that it was "expensive," "advanced," and "scary". Patients' implant knowledge came primarily from magazines or books, while professional dental societies/associations were the least sought out source of information. Patients believed that the purpose of dental implants was to avoid dentures and improve chewing function. Their primary concerns about dental implants were the cost and longevity. Approximately 12% of patients with dental implants and 61% of patients without implants did not know that bone grafts may be required and that sedation during surgery was an option. For patients who experienced sedation during the procedure, 60% of them want it for future surgeries. Patients also had limited knowledge of bone-graft materials and the effects of CBCT radiation; 75% of the patients expressed concerns over the safety of graft materials and radiation exposure. For patients with a history of dental implant therapy, 80% of them would recommend dental implants to their family and friends. CONCLUSIONS: Overall, patients' experiences with dental implant therapy were positive, but there was a lack of patient education regarding dental implants and their associated procedures. Dental professionals need to take the initiative to improve patient education.

Diagnosis of Tooth Prognosis Using Artificial Intelligence.

The accurate diagnosis of individual tooth prognosis has to be determined comprehensively in consideration of the broader treatment plan. The objective of this study was to establish an effective artificial intelligence (AI)-based module for an accurate tooth prognosis decision based on the Harvard School of Dental Medicine (HSDM) comprehensive treatment planning curriculum (CTPC). The tooth prognosis of 2359 teeth from 94 cases was evaluated with 1 to 5 levels (1-Hopeless, 5-Good condition for long term) by two groups (Model-A with 16, and Model-B with 13 examiners) based on 17 clinical determining factors selected from the HSDM-CTPC. Three AI machine-learning methods including gradient boosting classifier, decision tree classifier, and random forest classifier were used to create an algorithm. These three methods were evaluated against the gold standard data determined by consensus of three experienced prosthodontists, and their accuracy was analyzed. The decision tree classifier indicated the highest accuracy at 0.8413 (Model-A) and 0.7523 (Model-B). Accuracy with the gradient boosting classifier and the random forest classifier was 0.6896, 0.6687, and 0.8413, 0.7523, respectively. Overall, the decision tree classifier had the best accuracy among the three methods. The study contributes to the implementation of AI in the decision-making process of tooth prognosis in consideration of the treatment plan.

Current Implementation of Digital Dentistry for Removable Prosthodontics in US Dental Schools.

Objectives: Although digital technology has been widely integrated into dental education, there is limited literature investigating the extent of the integration of computer-aided design and computer-aided manufacturing (CAD-CAM) for removable systems in the dental curriculum. The purpose of this study was to assess the current implementation of CAD-CAM complete and partial dentures in predoctoral (PP) and advanced graduate prosthodontic (AGP) education in US dental schools. The study also aimed to identify potential barriers to its implementation in the dental curriculum. Methods: An online survey with 15 questions was created using online survey software. The survey was distributed to the directors of predoctoral prosthodontics in 56 schools and advanced graduate programs of prosthodontics in 52 schools listed in the 2018-19 American Dental Education Association (ADEA) Directory. Results: The percentage of programs (PP and AGP) implementing CAD-CAM complete dentures (CAD-CAM CDs) and CAD-CAM removable partial dentures (CAD-CAM RPDs) in their didactic, preclinical, and clinical curricula was recorded. CAD-CAM CDs are taught in didactic courses in 54.2% of PP and 65.2% of AGP. However, CAD-CAM RPDs are only taught in 37.5% of PP and 47.8% of AGP. Programs are largely limited by a lack of funds, resources, time, and faculty members. Conclusion: While digital technologies have indeed become more prevalent in dental education, many institutions face barriers to implementation. More research must be conducted in order to support the continued incorporation of digital technologies into dental education.

Importance of bitewing radiographs for the early detection of interproximal carious lesions and the impact on healthcare expenditure in Japan.

BACKGROUND: Globally, the direct cost of dental caries is approximately $298B yearly, consuming 5-10% of national healthcare budgets. Bitewing radiographs (BWR) are the standard method of diagnosing interproximal dental caries. In Japan, bitewing radiographs are rarely used. This retrospective observational study was conducted to measure the potential economic impact of carious lesions left undiagnosed and untreated due to this omission of bitewing radiographs. METHODS: The total number of existing carious lesions, the number of undiagnosed lesions, and costs of treating these lesions were calculated from the national database of Ministry of Health, Labor and Wellness in Japan between June 2013 and 2017. The number of affected teeth was estimated using prevalence data and undiagnosed lesions were estimated. The expense associated with treating progressed lesions was calculated using the standard Japanese fee structure. BWR trends were assessed, and analyses were performed to understand the differences between states and populations over time. RESULTS: The average number of BWR taken monthly per office was 48.3±1.1 (average ± SD). It was calculated that an average of 6,429,155 lesions went undiagnosed per month, 93.5 teeth per practice, and 1.6 teeth per patient. The cost of treating lesions that went undiagnosed and then progressed into more invasive restorations was estimated to be between $57M-$218M more (difference between NaF varnish and class II restorations), and $150M-$443M more (difference between Class II restoration and crown or crown with RCT). CONCLUSIONS: BWRs are crucial in diagnosing a significant number of carious lesions. There is considerable impact on health and cost to the national health system due to undiagnosed lesions. Practitioners need to be educated on reading and understanding BWR, and policy should be changed to cover BWR.

Accuracy of a Method to Monitor Root Position Using a 3D Digital Crown/Root Model during Orthodontic Treatments.

This study aimed to assess the accuracy of a method of predicting post-movement root position during orthodontic treatment using a 3D digital crown/root model (3DCRM) created with pre-movement records of both cone-beam computed tomography (CBCT) and dental arch digital scans. Pre- and post-movement CBCT scans and dental arch digital scans of five patients who had completed orthodontic treatments were used in this study. The 3DCRM was superimposed onto the post-movement scanned dental arch to identify the post-movement root position (test method). Post-movement CBCT (referenced as the current method) served as the control to identify the actual post-movement root position. 3D-coordinate analysis revealed no significant differences between the test and current methods along the X and Y axes. However, the discrepancy on the Z axis (especially in cases of intrusion) was greater than that in all other directions for all three tooth types examined (p < 0.05). A strong positive correlation between the degree of discrepancy and the distance of tooth movement was observed on the Z axis (r = 0.71). The 3DCRM method showed promising potential to accurately predict root position during orthodontic treatments without the need for a second CBCT. However, root resorption, which affected the Z axis prediction, needs to be closely monitored using periapical radiographs to complement this method.

Comprehensive Assessment of the Universal Healthcare System in Dentistry Japan: A Retrospective Observational Study.

Japan's universal healthcare insurance is facing economic challenges due to the advanced aging society, however, objective data of dental expenditure has never been introduced. This study aimed to identify the associated factors with dental expenditures using government-provided digitized insurance claims data and calculated the spending in the context of dental cost per person (DCPP). Seven associated factors analyzed were age, demographic, geographic, socioeconomic, regional wealth, the impact of the 8020-national campaign implementation (keep 20 teeth at age 80), and the effect of the home-visit dentistry for the elders. The average DCPP was high in older populations (75+) in all prefectures. The prefectures with the highest and lowest DCPP were significant compared to other states and retained their respective places in the cost hierarchy over the four years. The prefectures with more citizens participating in government assistance programs (GAP) had greater DCPPs. Dental costs were significantly related to geographic regions, age, per capita income, government assistance program prevalence, office complete denture frequency, and home visit care per patient. With a growing aging population, dental care costs will continue to increase, burdening its fiscal future. Associated factors identified should be considered to control the contentious increase of healthcare cost.