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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

Electric and Manual Oral Hygiene Routines Affect Plaque Index Score Differently.

This cross-sectional study aimed to examine the oral hygiene behaviors in the general population and identify factors affecting oral hygiene behaviors and plaque removal efficacy. A survey was distributed to patients through 11 dental practices in Japan, and each patient's plaque index score (PIS) was recorded. In total, 1184 patients participated (521 women and 660 men), with 84.04% using manual toothbrushes (MTBs) and 15.96% using electric toothbrushes (ETBs). ETB users had a significantly lower PIS compared to MTB users (p = 0.0017). In addition, a statistically significant difference in the PIS was detected in relation to the frequency of brushing per day (≥2 times) and time spent on brushing (≥1 min). Some MTB users spent less than 1 min brushing, while all ETB users spent at least 1 min brushing, and extended brushing periods significantly improved the PIS for the MTB users. MTB users tend to replace brush heads more frequently than ETB users, and the frequency of replacement affected the PIS significantly (p < 0.01) for the MTB users. The status of dental treatment (first visit, in treatment versus recall) also significantly affected the PIS (p < 0.01). The ETB was more effective than the MTB in terms of better plaque removal and reduced frequency of brush head replacement.

3D digital analysis of tooth movement with magnets and elastics in vitro.

OBJECTIVES: Magnets have many advantages in orthodontics, and our previous studies confirmed their therapeutic potential through 3D-data analysis. The aim of this study was to compare tooth movements, including rotation, obtained via magnetic and elastic forces in crowded cases in vitro. METHODS: Typodont models mimicking a crowded case were prepared. In the magnetic force-driven orthodontics (MG) group, Nd-Fe-B magnets were attached to the labial surfaces from UR4 to UL4 for attracting force, and to UR6 and UL6 for repulsing force. For the elastic force-driven orthodontic (EL) group, brackets were placed on labial surfaces from UR2 to UL2 with power-chain elastics. A NiTi archwire was used in both groups. The models were 3D scanned before and after tooth movement and exported as STL files. The pre- and post-movement STL files were superimposed. The 3D coordinates of the measurement points of the crown and root apex were obtained, and tooth displacement, 3D movements (X, Y, and Z-axis), and rotation (yaw, pitch, and roll) were calculated. Two-tailed Student's t-test was performed for comparison of the results between MG and EL groups (n = 3). RESULTS: Overall, both groups indicated similar movement and rotation to achieve the planned arch form. In the crown movement and rotation, no significant differences were observed between MG and EL groups. However, in the root movement, there was a significant difference between MG and EL groups in X and Z axis for the canines. CONCLUSIONS: Magnetic force-driven orthodontics demonstrated comparable results to elastics with less tipping movement, suggesting a potential future orthodontic modality. CLINICAL SIGNIFICANCE: This in vitro study showed the potential of magnetic force for orthodontic application. The magnetic force-driven orthodontics might provide less tipping tooth movement compared to conventional methods, such as power chains, and could be a future technique for comprehensive orthodontic treatment.

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.

An In Vivo Spectrophotometric Analysis of Gingival Acrylic Shade Guide.

Selecting shades of acrylic gingival restorative material is challenging. This study examined the shade appropriateness of five acrylic gingival restorative materials. The color was analyzed using an intraoral spectrophotometer (Crystaleye®, Olympus). The gingival color of maxillary incisors for eighty-nine patients was measured. CIELAB color coordinates (L*, a* and b*) were obtained, and the color difference ∆E (Coverage Error: CE) between shade tabs and natural gingival color of patient samples for each shade guide system were compared. Repeated ANOVA and post hoc analyses with Tukey's HSD were performed. There was a significant difference among the mean minimum CEs of the tab sets (p < 0.01). GC Acrylic (CE = 5.89 ∆E ± 2.97) and Lucitone 199® (CE = 6.55 ± 3.33) groups exhibited CEs significantly lower than all other groups (all p < 0.001). The IvoCap® system exhibited the highest CE (10.78 ± 3.80), significantly greater than all other groups (p < 0.001). No significant differences were observed based on sex (p = 0.055) or ethnicity (p = 0.327). The GC Acrylic and Lucitone 199® shade guides showed the lowest CEs. All guides had coverage errors above 5.89 ∆E, which is larger than ∆E thresholds of acceptability. Of the materials evaluated in this study, GC Acrylic and Lucitione 199® are best able to reproduce the clinical appearance of the gingival tissue. Many patients have tissue that cannot be reproduced accurately with currently available materials.

Association between cognitive health and masticatory conditions: a descriptive study of the national database of the universal healthcare system in Japan.

Cognitive health is subject to decline with increasing numbers of lost teeth which impacts mastication. This study is a descriptive data analysis of the association between masticatory and cognitive conditions using a large database. We obtained the dental and medical records from Japan's universal healthcare system (UHCS) from the national database in 2017. The data from 94% of the Japanese population aged 65 and over is included. It is inclusive of diagnostic codes for various types of cognitive impairment, as well as dental treatment records from 2012 to 2017. The cognitive impairment group was compared to those without a diagnosis of cognitive impairment. Crude odds ratio between loss of mastication with natural teeth (exposure) and cognitive impairments (outcome) were compared. Patients who have lost masticatory function are likely to have cognitive impairment with an odds ratio of 1.89 (p<0.0001) for early elderly (aged 65-75) and 1.33 (p<0.0001) for advanced elderly (over 75). Patients who are edentulous and function with complete dentures are likely to have cognitive impairment with an odds ratio of 2.38 (p<0.0001) and 1.38 (p<0.0001), respectively. The data shows a convincing and significant result of an association between cognitive health and oral health, related to masticatory conditions.

Effects of healthcare policy and education on reading accuracy of bitewing radiographs for interproximal caries.

OBJECTIVES: The aim of this study is to assess the accuracy of bitewing radiograph interpretation of predoctoral students, residents and general dentists who work under different core curriculum of dental education and healthcare policy. METHODS: A total of 118 examiners including predoctoral dental students, residents and general dentists from USA and Japan were tasked with evaluating a series of bitewing radiographs and diagnosing interproximal carious lesions. This study was approved by the Harvard Medical School Institutional Review Board (IRB). Participants graded interproximal aspects of those images and categorized the following criteria; "intact", "enamel caries <1/2 width", "enamel caries >1/2 width" or "caries into dentin". The gold-standard was determined by the consensus of two HSDM full-time faculty. RESULTS: There was significant difference in the sensitivity for all three caries levels between the two groups but there was no significant difference on specificity. The positive-predictive and negative-predictive values of the USA group for the enamel caries (<1/2 of enamel) were significantly higher than the Japanese group. The average of AUC (ROC) was significantly higher in the USA group (0.885 ± 0.04) than the Japanese group (0.785 ± 0.08, p<0.01). CONCLUSION: Teaching and adopting BW radiographs for diagnosis of interproximal caries is integral for dental providers to accurately and efficiently use them in their practices. It is critical that all dental educators approach policymakers to explain the importance of BW radiographs and promote their efficacy for prevention and early diagnosis of interproximal caries.

Biological efficacy of perpendicular type-I collagen protruded from TiO2-nanotubes.

The aim of this study was to evaluate the biological efficacy of a unique perpendicular protrusion of type-I collagen (Col-I) from TiO2 nanotubes (NT-EPF surface). We hypothesized that the NT-EPF surface would play bifunctional roles in stimulating platelet-mediated fibroblast recruitment and anchoring fibroblast-derived Col-I to form a perpendicular collagen assembly, mimicking the connective tissue attachment around natural teeth for the long-term maintenance of dental implants. Ti surface modification was accomplished in two steps. First, TiO2 nanotubes (NT) array was fabricated via anodization. Diameters and depths of NTs were controlled by applied voltage and duration. Subsequently, an electrophoretic fusion (EPF) method was applied to fuse Col-I into nanotube arrays in a perpendicular fashion. Surface wettability was assessed by contact angle measurement. The bioactivity of modified TiO2 surfaces was evaluated in terms of NIH3T3 fibroblast attachment, platelet activation, and collagen extension. Early attachment, aggregation, and activation of platelets as well as release of platelet-related growth factors were demonstrated on NT-EPF surfaces. Platelet-mediated NIH3T3 cells migration toward NT-EPF was significantly increased and the attached cells showed a typical fibrous morphology with elongated spindle shape. A direct linkage between pseudopod-like processes of fibroblasts to NT-EPF surfaces was observed. Furthermore, the engineered EPF collagen protrusion linked with cell-derived collagen in a perpendicular fashion. Within the limitation of this in vitro study, the TiO2 nanotube with perpendicular Col-I surface (NT-EPF) promoted better cell attachment, induced a strong platelet activation which suggested the ability to create a more robust soft tissue seal.

Effect of Magnet Position on Tipping and Bodily Tooth Movement in Magnetic Force-Driven Orthodontics.

The goal of our study is to launch magnetic force-driven orthodontics. This continuous study investigated the influence of magnet position on tipping and bodily tooth movement, using 3D printing technology and digital analysis. Orthodontic typodont models (TMs) for space-closure were 3D printed to mimic maxillary central incisors. Nd-Fe-B magnets were placed in the middle third (Model-M), and the cervical third (Model-C), of the tooth. TMs, before and after movement, were digitally scanned and superimposed. The 3D digital coordinates (X, Y, and Z axes), and rotations (yaw, pitch, and roll) of the tooth crown and root, were calculated and compared between the two magnet position settings. Model-M showed higher rates of movement, but more rotation than Model-C (p < 0.01). The root apex of Model-M moved in the opposite direction of the crown (R = -0.29), indicating tipping movement. In contrast, the crown and root apex moved in the same direction (R = 0.56) in Model-C, indicating bodily movement. These patterns were confirmed in a typodont model of a moderate crowding case. The results validated that modifying the magnet position increased the amount of bodily tooth movement, and decreased rotation/tipping in an ex vivo setting.