Nonionizing diagnostic imaging modalities for visualizing health and pathology of periodontal and peri-implant tissues.

Radiographic examination has been an essential part of the diagnostic workflow in periodontology and implant dentistry. However, radiographic examination unavoidably involves ionizing radiation and its associated risks. Clinicians and researchers have invested considerable efforts in assessing the feasibility and capability of utilizing nonionizing imaging modalities to replace traditional radiographic imaging. Two such modalities have been extensively evaluated in clinical settings, namely, ultrasonography (USG) and magnetic resonance imaging (MRI). Another modality, optical coherence tomography (OCT), has been under investigation more recently. This review aims to provide an overview of the literature and summarize the usage of USG, MRI, and OCT in evaluating health and pathology of periodontal and peri-implant tissues. Clinical studies have shown that USG could accurately measure gingival height and crestal bone level, and classify furcation involvement. Due to physical constraints, USG may be more applicable to the buccal surfaces of the dentition even with an intra-oral probe. Clinical studies have also shown that MRI could visualize the degree of soft-tissue inflammation and osseous edema, the extent of bone loss at furcation involvement sites, and periodontal bone level. However, there was a lack of clinical studies on the evaluation of peri-implant tissues by MRI. Moreover, an MRI machine is very expensive, occupies much space, and requires more time than cone-beam computed tomography (CBCT) or intraoral radiographs to complete a scan. The feasibility of OCT to evaluate periodontal and peri-implant tissues remains to be elucidated, as there are only preclinical studies at the moment. A major shortcoming of OCT is that it may not reach the bottom of the periodontal pocket, particularly for inflammatory conditions, due to the absorption of near-infrared light by hemoglobin. Until future technological breakthroughs finally overcome the limitations of USG, MRI and OCT, the practical imaging modalities for routine diagnostics of periodontal and peri-implant tissues remain to be plain radiographs and CBCTs.

Radiographic assessment of the peri-implant site.

While peri-implant mucositis relies solely on clinical parameters, radiological assessment becomes indispensable for diagnosing peri-implantitis. Intraoral radiography, with its simplicity of application, low radiation exposure, and adequate representation of peri-implant structures, stands out as the standard of care for both immediate and follow-up assessments. Standardization by custom-made radiologic splints allows for excellent comparability with previous images and allows for the determination of even small changes in contour and density of the peri-implant bone. Furthermore, other radiographic modalities like panoramic radiography and cone beam computed tomography (CBCT) may provide useful features for specific patients and clinical cases while also showing innate limitations. Beyond the assessment of the marginal peri-implant bone level as the crucial parameter of clinical relevance, radiologic assessment may reveal various other findings related to the prosthetic restoration itself, the precision of its fit to the implant, and the peri-implant soft and hard tissues. Since such findings can be crucial for the assessment of peri-implant health and the implants' prognosis, a systematic diagnostic evaluation pathway for a thorough assessment is recommended to extract all relevant information from radiologic imaging. This article also provides an overview of the clinical and chronological indications for different imaging modalities in peri-implant issues.

Scoring facial attractiveness with deep convolutional neural networks: How training on standardized images reduces the bias of facial expressions.

OBJECTIVE: In many medical disciplines, facial attractiveness is part of the diagnosis, yet its scoring might be confounded by facial expressions. The intent was to apply deep convolutional neural networks (CNN) to identify how facial expressions affect facial attractiveness and to explore whether a dedicated training of the CNN is able to reduce the bias of facial expressions. MATERIALS AND METHODS: Frontal facial images (n = 840) of 40 female participants (mean age 24.5 years) were taken adapting a neutral facial expression and the six universal facial expressions. Facial attractiveness was computed by means of a face detector, deep convolutional neural networks, standard support vector regression for facial beauty, visual regularized collaborative filtering and a regression technique for handling visual queries without rating history. CNN was first trained on random facial photographs from a dating website and then further trained on the Chicago Face Database (CFD) to increase its suitability to medical conditions. Both algorithms scored every image for attractiveness. RESULTS: Facial expressions affect facial attractiveness scores significantly. Scores from CNN additionally trained on CFD had less variability between the expressions (range 54.3-60.9 compared to range: 32.6-49.5) and less variance within the scores (P ≤ .05), but also caused a shift in the ranking of the expressions' facial attractiveness. CONCLUSION: Facial expressions confound attractiveness scores. Training on norming images generated scores less susceptible to distortion, but more difficult to interpret. Scoring facial attractiveness based on CNN seems promising, but AI solutions must be developed on CNN trained to recognize facial expressions as distractors.

[Komplexes Odontom im Unterkieferfrontzahnbereich bei einer 16-jährigen Patientin - Diagnostik, Therapie und Nachsorge].

Odontome gelten zusammen mit den Amelo- blastomen als die häufigsten odontogenen Tumoren. Sie entstehen während der embryo- nalen Zahnkeimentwicklung durch fehlerhaft differenziertes Keimgewebe und werden daher auch als Hamartome bezeichnet. Somit sind sie also strenggenommen keine klassischen Neoplasien.

Radiographic diagnosis of periodontal diseases - Current evidence versus innovations.

Accurate diagnosis of periodontal and peri-implant diseases relies significantly on radiographic examination, especially for assessing alveolar bone levels, bone defect morphology, and bone quality. This narrative review aimed to comprehensively outline the current state-of-the-art in radiographic diagnosis of alveolar bone diseases, covering both two-dimensional (2D) and three-dimensional (3D) modalities. Additionally, this review explores recent technological advances in periodontal imaging diagnosis, focusing on their potential integration into clinical practice. Clinical probing and intraoral radiography, while crucial, encounter limitations in effectively assessing complex periodontal bone defects. Recognizing these challenges, 3D imaging modalities, such as cone beam computed tomography (CBCT), have been explored for a more comprehensive understanding of periodontal structures. The significance of the radiographic assessment approach is evidenced by its ability to offer an objective and standardized means of evaluating hard tissues, reducing variability associated with manual clinical measurements and contributing to a more precise diagnosis of periodontal health. However, clinicians should be aware of challenges related to CBCT imaging assessment, including beam-hardening artifacts generated by the high-density materials present in the field of view, which might affect image quality. Integration of digital technologies, such as artificial intelligence-based tools in intraoral radiography software, the enhances the diagnostic process. The overarching recommendation is a judicious combination of CBCT and digital intraoral radiography for enhanced periodontal bone assessment. Therefore, it is crucial for clinicians to weigh the benefits against the risks associated with higher radiation exposure on a case-by-case basis, prioritizing patient safety and treatment outcomes.

Effects of nanomodified titanium surfaces considering bacterial colonization and viability of osteoblasts and fibroblasts.

This study investigates nanostructured titanium surfaces (Ti2 spikes) that promote the viability of osteoblasts and fibroblasts and prevent bacterial colonisation. Helium ion irradiation was adopted to produce nanometric-sized cones on titanium. Human osteoblasts (hFOB) and human gingiva fibroblasts (hGF) were used for analysis. A viability and a cytotoxicity assay were conducted to evaluate the lactate dehydrogenase (LDH) activity and assess cell damage in Ti2 spikes compared to titanium discs with a sandblasted and acid-etched (Ti2 SLA) surface. The antibacterial activity was investigated against Escherichia coli, Streptococcus mutans, Fusobacterium nucleatum, and Porphyromonas gingivalis. In the course of the cultivation, both hGF and hFOB demonstrated significantly reduced viability on the Ti2 spikes surface. hGF cells exhibited a slight but significant increase in LDH release. In contrast, hFOB showed reduced cytotoxicity on this surface. On the Ti2 spikes surface, hGF cells exhibited a significant reduction in gene expression of VCL, Src-1, and ITGα5. However, the integrin subunits ITGα1 and ITGα3 showed upregulation on the Ti2 spikes surface. The Ti2 spikes surface significantly increased the expression of almost all osteogenic markers. The results of conventional culturing demonstrated a statistically significant decrease in the number of viable cells for S. mutans, F. nucleaum, and greater quantities of P. gingivalis on Ti2 spikes surface compared to control. However, no such reduction was detected for E. coli. The long-term success of implants relies on establishing and maintaining hard and soft peri-implant tissues. Ti2 spikes represent a novel and promising approach to enhance osseointegration and optimize biocompatibility.

[Neurologischer Notfall nach dentaler Implantation - was nun?]

Mit der Verbreitung von Zahnimplantaten ist die Zahl neurologischer Komplikationen gestiegen, wobei diese vor allem im Unterkiefer vorkommen. Verletzungen des Nervus alveo- laris inferior sind eine ernste Komplikation mit Inzidenzen für transiente Nervschäden bis zu 24% und persistierenden Schädigungen bis zu 11%.

Performance of a commercially available Generative Pre-trained Transformer (GPT) in describing radiolucent lesions in panoramic radiographs and establishing differential diagnoses.

OBJECTIVES: To evaluate the performance of a commercially available Generative Pre-trained Transformer (GPT) in describing and establishing differential diagnoses for radiolucent lesions in panoramic radiographs. MATERIALS AND METHODS: Twenty-eight panoramic radiographs, each containing a single radiolucent lesion, were evaluated in consensus by three examiners and a commercially available ChatGPT-3.5 model. They provided descriptions regarding internal structure (radiodensity, loculation), periphery (margin type, cortication), shape, location (bone, side, region, teeth/structures), and effects on adjacent structures (effect, adjacent structure). Diagnostic impressions related to origin, behavior, and nature were also provided. The GPT program was additionally prompted to provide differential diagnoses. Keywords used by the GPT program were compared to those used by the examiners and scored as 0 (incorrect), 0.5 (partially correct), or 1 (correct). Mean score values and standard deviation were calculated for each description. Performance in establishing differential diagnoses was assessed using Rank-1, -2, and - 3. RESULTS: Descriptions of margination, affected bone, and origin received the highest scores: 0.93, 0.93, and 0.87, respectively. Shape, region, teeth/structures, effect, affected region, and nature received considerably lower scores ranging from 0.22 to 0.50. Rank-1, -2, and - 3 demonstrated accuracy in 25%, 57.14%, and 67.85% of cases, respectively. CONCLUSION: The performance of the GPT program in describing and providing differential diagnoses for radiolucent lesions in panoramic radiographs is variable and at this stage limited in its use for clinical application. CLINICAL RELEVANCE: Understanding the potential role of GPT systems as an auxiliary tool in image interpretation is imperative to validate their clinical applicability.

Prevalence and correlation with sex, age, and dental status of bone apposition at the mandibular angle and radiographic alterations of the temporomandibular joints: a retrospective observational study in an adult Swiss population.

BACKGROUND: The purpose of this study was to determine the prevalence of radiographic changes in the mandibular angle (bone apposition) and osseous alterations in the temporomandibular joints (TMJs) in the adult population of Switzerland. In addition, the study intended to investigate possible correlations between the two sites of contour bone changes (mandibular angle and TMJ) and to analyze various patient-related factors, including sex, age, dental status, and medical history. METHODS: Panoramic radiographs of 600 patients distributed into six age groups (283 females, 317 males, aged 20 to 79 years) were included to evaluate radiographic changes. The bone in the mandibular angle region and the shape of the condylar heads were examined for contour changes (bone apposition at the jaw angles and osseous changes of the TMJs). General estimating equations, binormal tests, and chi-squared tests were used for statistical analysis. RESULTS: Approximately half of the mandibular angles (47.8%) showed bone apposition, mostly bilateral. TMJ alterations were less common (27%), often unilateral, with flattening being the most frequent finding. No significant correlation was found between the two sites. Bone apposition at the mandibular angle showed a significant male predominance, whereas TMJ changes did not differ by sex. Alterations in both sites increased with age, and were not related to dental status or analgesic use. CONCLUSIONS: Bone apposition at the mandibular angle should be interpreted as part of the natural functional adaptation of the bone associated with aging. Assuming that parafunctional habits may influence the development and progression of alterations in the mandibular angle or TMJs, the presence of radiographic changes in these areas should prompt dental clinicians to investigate further in this direction. TRIAL REGISTRATION: The study was approved by the Swiss Association of Research Ethics Committees (swissethics), BASEC reference number: 2020-00963 (25.05.2020).

Frontiers in Three-Dimensional Surface Imaging Systems for 3D Face Acquisition in Craniofacial Research and Practice: An Updated Literature Review.

Digitalizing all aspects of dental care is a contemporary approach to ensuring the best possible clinical outcomes. Ongoing advancements in 3D face acquisition have been driven by continuous research on craniofacial structures and treatment effects. An array of 3D surface-imaging systems are currently available for generating photorealistic 3D facial images. However, choosing a purpose-specific system is challenging for clinicians due to variations in accuracy, reliability, resolution, and portability. Therefore, this review aims to provide clinicians and researchers with an overview of currently used or potential 3D surface imaging technologies and systems for 3D face acquisition in craniofacial research and daily practice. Through a comprehensive literature search, 71 articles meeting the inclusion criteria were included in the qualitative analysis, investigating the hardware, software, and operational aspects of these systems. The review offers updated information on 3D surface imaging technologies and systems to guide clinicians in selecting an optimal 3D face acquisition system. While some of these systems have already been implemented in clinical settings, others hold promise. Furthermore, driven by technological advances, novel devices will become cost-effective and portable, and will also enable accurate quantitative assessments, rapid treatment simulations, and improved outcomes.

The use of CBCT in orthodontics with special focus on upper airway analysis in patients with sleep-disordered breathing.

Applications of cone-beam CT (CBCT) in orthodontics have been increasingly discussed and evaluated in science and practice over the last two decades. The present work provides a comprehensive summary of current consolidated practice guidelines, cutting-edge innovative applications, and future outlooks about potential use of CBCT in orthodontics with a special focus on upper airway analysis in patients with sleep-disordered breathing. The present scoping review reveals that clinical applications of CBCT in orthodontics are broadly supported by evidence for the diagnosis of dental anomalies, temporomandibular joint disorders, and craniofacial malformations. On the other hand, CBCT imaging for upper airway analysis-including soft tissue diagnosis and airway morphology-needs further validation in order to provide better understanding regarding which diagnostic questions it can be expected to answer. Internationally recognized guidelines for CBCT use in orthodontics are existent, and similar ones should be developed to provide clear indications about the appropriate use of CBCT for upper airway assessment, including a list of specific clinical questions justifying its prescription.

Feasibility of frozen soft tissues to simulate fresh soft tissue conditions in cone beam CT scans.

OBJECTIVES: To evaluate the feasibility of frozen soft tissues in simulating fresh soft tissues of pig mandibles using cone beam CT (CBCT). METHODS: Two fresh pig mandibles with soft tissues containing 2 tubes filled with a radiopaque homogeneous solution were scanned using 4 CBCT units and 2 field-of-view (FOV) sizes each. The pig mandibles were deep-frozen and scanned again. Three cross-sections were exported from each CBCT volume and grouped into pairs, with one cross-section representing a fresh and one a frozen mandible. Three radiologists compared the pairs and attributed a score to assess the relative image quality using a 5-point scale. Mean grey values and standard deviation were obtained from homogeneous areas in the tubes, compared using the Wilcoxon matched-pair signed-rank test and subjected to Pearson correlation analysis between fresh and frozen physical states (α = .05). RESULTS: Subjective evaluation revealed similarity of the CBCT image quality between fresh and frozen states. The distribution of mean grey values was similar between fresh and frozen states. Mean grey values of the frozen state in the small FOV were significantly greater than those of the fresh state (P = .037), and noise values of the frozen state in the large FOV were significantly greater than those of the fresh state (P = 0.007). Both mean grey values and noise exhibited significant and positive correlations between fresh and frozen states (P < 0.01). CONCLUSIONS: The freezing of pig mandibles with soft tissues may serve as a method to prolong their usability and working time when CBCT imaging is planned.

Antimicrobial effect of probiotic bacteriocins on Streptococcus mutans biofilm in a dynamic oral flow chamber model - an in vitro study.

Aim: To determine the antimicrobial activity of the bacteriocin-producing probiotic strains Streptococcus salivarius K12 and Streptococcus salivarius M18 alone or in combination against caries-associated Streptococcus mutans. Methods: Antimicrobial activity of S. salivarius K12 and/or S. salivarius M18 against S. mutans ATCC 25175 growth and biofilm formation on hydroxyapatite (HA) discs was determined in a flow chamber model by recording the colony forming units (CFU/ml) after 48 h of co-cultivation. The biofilm was analyzed by scanning electron microscopy (SEM) and by confocal laser scanning microscopy (CLSM). Additionally, the simultaneous antagonism assay was used to assess the inhibitory effect of S. salivarius K12 and/or S. salivarius M18 against S. mutans ATCC 25175 and 21 clinical isolates of S. mutans. Results: Co-cultivation of S. mutans and S. salivarius K12 and/or S. salivarius M18 led to the inhibition of S. mutans viability, thereby, preventing its biofilm formation on HA discs. Furthermore, S. salivarius K12 and S. salivarius M18 exhibited antimicrobial activity against most clinical isolates of S. mutans. Conclusion: The in vitro flow chamber system used in this study allows the simulation of time-dependent administration of S. salivarius probiotic strains, either alone or in combination, to investigate the prevention of S. mutans biofilm formation in a standardized model.

Dental caries and associated factors in 7-, 12- and 15-year-old schoolchildren in the canton of Basel-Landschaft, Switzerland: Changes in caries experience from 1992 to 2021.

BACKGROUND: Epidemiological surveys in schoolchildren are used to assess the current status of oral health. AIM: To investigate the changes in caries experience among schoolchildren in the canton of Basel-Landschaft, Switzerland, over a period of three decades. Secondary objectives were to evaluate the impact of various personal and demographic factors such as age group, place of residence or dental hygiene awareness on caries prevalence as well as the history of orthodontic treatment in the year 2021. DESIGN: A random sampling of school classes from first, sixth and ninth grades, that is schoolchildren aged 7, 12 and 15 years, was performed. Children's dmft and DMFT scores were determined according to the WHO methodology while information on oral hygiene habits and dental prophylaxis awareness was collected by means of a questionnaire directed to the legal guardians of the children. Individual logistic regressions were performed to identify possible influencing factors for caries. RESULTS: A total of 1357 schoolchildren could be included in the study. In the year 2021, the youngest age group had an average of 0.68 primary teeth that needed treatment, whereas the 12- and 15-year-olds each had approximately 0.3 permanent teeth requiring treatment. While these numbers remained constant over the examination period of three decades, most of the other caries indices improved. Younger children (p = .001) and children with a migrant background (p < .001) were found to be risk groups. Orthodontic treatment was more frequent in females, schoolchildren of Swiss nationality and children attending higher secondary schools at ninth grade. CONCLUSION: This study demonstrated that even in a country with a low prevalence of caries experience, untreated carious lesions remain a problem as their prevalence remained unchanged over the examination period of three decades.

The current role and future potential of digital diagnostic imaging in implant dentistry: A scoping review.

OBJECTIVES: Diagnostic imaging is crucial for implant dentistry. This review provides an up-to-date perspective on the application of digital diagnostic imaging in implant dentistry. METHODS: Electronic searches were conducted in PubMed focusing on the question 'when (and why) do we need diagnostic imaging in implant dentistry?' The search results were summarised to identify different applications of digital diagnostic imaging in implant dentistry. RESULTS: The most used imaging modalities in implant dentistry include intraoral periapical radiographs, panoramic views and cone beam computed tomography (CBCT). These are dependent on acquisition standardisation to optimise image quality. Particularly for CBCT, other technical parameters (i.e., tube current, tube voltage, field-of-view, voxel size) are relevant minimising the occurrence of artefacts. There is a growing interest in digital workflows, integrating diagnostic imaging and automation. Artificial intelligence (AI) has been incorporated into these workflows and is expected to play a significant role in the future of implant dentistry. Preliminary evidence supports the use of ionising-radiation-free imaging modalities (e.g., MRI and ultrasound) that can add value in terms of soft tissue visualisation. CONCLUSIONS: Digital diagnostic imaging is the sine qua non in implant dentistry. Image acquisition protocols must be tailored to the patient's needs and clinical indication, considering the trade-off between radiation exposure and needed information. growing evidence supporting the benefits of digital workflows, from planning to execution, and the future of implant dentistry will likely involve a synergy between human expertise and AI-driven intelligence. Transiting into ionising-radiation-free imaging modalities is feasible, but these must be further developed before clinical implementation.

Stannous Source in Toothpastes Leads to Differences in Their Antimicrobial Efficacy.

PURPOSE: The aim of this in-vitro study was to investigate the antimicrobial efficacy of identical experimental toothpastes with different stannous sources. MATERIALS AND METHODS: Streptococcus mutans biofilms were grown on protein-coated glass disks in static conditions for 24 h and thereafter exposed to toothpaste slurries or physiological saline (negative control; n = 15) for 30 s. Four experimental toothpastes were applied in this study, containing either stannous chloride (SnCl2; B: 3500 ppm Sn2+, and D: 3600 ppm Sn2+) or stannous fluoride (SnF2; C: 3500 ppm Sn2+, and E: 3600 ppm Sn2+). Marketed toothpaste meridol® (A: 3300 ppm SnF2) served as control. All five toothpastes contained amine fluoride (AmF). The biofilms were placed on agar surface and their metabolic activity was assessed by isothermal microcalorimetry over 96 h. The heat flow data was analysed for growth rate and lag time using grofit package in software R. Additionally, reduction of active biofilm compared to untreated control was calculated. RESULTS: All toothpastes significantly prolong the lag time of treated biofilms in comparison to negative control (p < 0.05). Toothpastes containing SnF2 (C and E) prolonged the lag time statistically significantly compared to toothpastes containing SnCl2 (B and D) (p < 0.05). The maximum growth rate was statistically significantly reduced by all tested toothpastes compared to the untreated control group (p < 0.05). Toothpastes containing SnF2 (A, C and E) reached 59.9 ± 7.8, 61.9 ± 7.7, and 55.6 ± 7.0% reduction of active biofilm, respectively. Thus, they exhibit statistically significantly better results than toothpastes B (52.9 ± 9.9%) and D (44.7 ± 7.6%). Toothpaste D, which contains a slightly higher concentration of Sn2+, was the least effective in reducing active biofilm. CONCLUSION: The toothpastes containing SnF2 combined with AmF had the highest antimicrobial efficacy in this study.

Inhibitory effect of natural flavone luteolin on Streptococcus mutans biofilm formation.

Streptococcus mutans is one of the key pathogens responsible for dental caries, which is known to be one of the most prevalent biofilm-associated diseases worldwide. S. mutans virulence strongly depends on its biofilm formation and enamel demineralization abilities due to the production of surface adhesins, exopolysaccharides, and acid in the presence of sugar. Luteolin is an abundant natural flavone with a prominent anti-bacterial function. However, it remains unclear how luteolin affects S. mutans pathogenicity including its acidogenicity and biofilm formation. In this study, the effect of luteolin on S. mutans growth, acid production, and its early and late biofilm formation and biofilm disruption was tested. Luteolin shows strong anti-biofilm activity, while it remains non-toxic for bacterial cell viability. In the biofilm, luteolin reduces the expression of S. mutans virulence genes such as gbpC, spaP, gtfBCD, and ftf encoding for surface adhesins and extracellular polysaccharides (EPS)-producing enzymes, which reflects in the strong reduction of bacteria and EPS. Further, it reduces water-insoluble glucan production in the biofilm, potentially, via direct interference with glucosyltransfereases (Gtfs). Moreover, at biofilm inhibitory concentrations, luteolin significantly reduces acid production by S. mutans. Finally, luteolin could target S. mutans amyloid proteins to disrupt the biofilm based on the observation that it inhibits the uptake of the amyloid dye, thioflavin T, by S. mutans extracellular proteins and failed to inhibit biofilm formation by the mutant strain lacking three main amyloid proteins. In conclusion, luteolin appears to be a potent natural compound with pleiotropic anti-biofilm properties against one of the main cariogenic human pathogens, S. mutans. IMPORTANCE Flavonoids are natural compounds with proven anti-bacterial and anti-biofilm properties. Here, we describe the anti-biofilm properties of natural flavone luteolin against the main cariogenic bacteria, S. mutans. Luteolin inhibited gene expression of cell surface adhesins, fructosyltransferases, and glucosyltransferases, which promotes a significant reduction of bacterial and EPS biomass in early and late biofilms. Moreover, luteolin could directly target S. mutans Gtfs and functional amyloids to modulate pathogenic biofilms. These observations provide important insights into the anti-biofilm properties of luteolin while laying out a framework for future therapeutic strategies targeting biofilm-associated virulence factors of oral pathogens.

Effect of triangular mesh resolution on the geometrical trueness of segmented CBCT maxillofacial data into STL format.

OBJECTIVES: To determine the optimal level of mesh reduction that would maintain acceptable levels of geometrical trueness while also minimizing the impact on other parameters such as file size and processing time. METHODS: Intraoral and extraoral maxillofacial defects were created on 8 cadaver heads and scanned by using a CBCT scanner (NewTom 3D Imaging, Verona). DICOM data were segmented to produce head (n=8) and skull models (n=8) saved as standard tessellation language (STL) files. A further processing of head models was preformed to produce face (n=8) and ear models (n=8). A mesh reduction process was performed for each STL model (reference, R0) by generating 50% (R1), 75% (R2), and 90% (R3) reductions. The 3 datasets were compared to the R0 file using 3D evaluation software (GOM Inspect) using a global best-fit algorithm, to calculate the root mean square (RMS) deviations. Statistical analyses were performed at a level of significance of α=0.05. RESULTS: There was no 3D deviation after the 50% triangular mesh reduction in the 4 datasets. Minor 3D deviations were observed after 75% reduction, in all groups. After 90% reduction, higher 3D deviations were observed, and especially in head and skull. Statistically significant increase in 3D deviations was observed with higher degrees of mesh reduction (p < 0.001). CONCLUSION: The resolution of CBCT-based maxillofacial defect models can be reduced up to 50%, with neglectable concern to inaccuracy. CLINICAL SIGNIFICANCE: Accurate maxillofacial models can be obtained from CBCT DICOM files after segmentation and export as STL files, even when the mesh resolution is reduced up to 50%. This information can be valuable for practitioners and researchers working with 3D models of maxillofacial defects.

Group 3 ITI Consensus Report: Materials and antiresorptive drug-associated outcomes in implant dentistry.

OBJECTIVES: The aim of Working Group 3 was to address the influence of both material- and anti-resorptive drug- related factors on clinical and biological outcomes and complications in implant dentistry. Focused questions were addressed on (a) implant materials other than titanium (alloy)s, (b) transmucosal abutment materials and (c) medications affecting bone metabolism were addressed. MATERIALS AND METHODS: Three systematic reviews formed the basis for discussion in Group 3. Consensus statements and clinical recommendations were formulated by group consensus based on the findings of the systematic reviews. Patient perspectives and recommendations for future research were also conveyed. These were then presented and accepted following further discussion and modifications as required by the plenary. RESULTS: Zirconia is a valid alternative to titanium as material for implant and transmucosal components, allowing soft and hard tissue integration with clinical outcomes-identified by implant survival, marginal bone loss and peri-implant probing depths-up to 5-years comparable to titatnium. However, most of the evidence for zirconia implants is based on 1-piece implants limiting the indication range. Furthermore, based on expert opinion, zirconia transmucosal components might be preferred in the esthetic zone. In patients receiving low-dose bisphosphonate therapy, the rate of early implant failure is not increased, while the long-term effects remain poorly studied. Although it has not been sufficiently addressed, similar outcomes can be expected with low-dose denosumab. A drug holiday is not recommended when considering implant placement in patients treated with low-dose ARD. However, the specific therapeutic window, the cumulative dose and the administration time should be considered. Access to peri-implant supportive care is mandatory to prevent peri-implantitis-related medication-related osteonecrosis of the jaw (MRONJ) or implant-related sequestra (IRS). In patients receiving low-dose anti-resorptive drugs (ARD) therapy, the risk of complications related to implant placement is high, and implant procedures in this specific population should be strictly treated in a comprehensive multidisciplinary center. Finally, healthy dental implants should not be removed before low or high-dose ARD. CONCLUSIONS: Zirconia implants can be an alternative to titanium implants in selected indications. However, the current state of evidence remains limited, especially for 2-piece implant designs. Administration of low-dose ARD did not show any negative impact on early implant outcomes, but careful follow-up and supportive care is recommended in order to prevent peri-implant MRONJ and IRS. Implant placement in high-dose patients must be strictly considered in a comprehensive multidisciplinary center.

Piranha-etched titanium nanostructure reduces biofilm formation in vitro.

OBJECTIVES: Nano-modified surfaces for dental implants may improve gingival fibroblast adhesion and antibacterial characteristics through cell-surface interactions. The present study investigated how a nanocavity titanium surface impacts the viability and adhesion of human gingival fibroblasts (HGF-1) and compared its response to Porphyromonas gingivalis with those of marketed implant surfaces. MATERIAL AND METHODS: Commercial titanium and zirconia disks, namely, sandblasted and acid-etched titanium (SLA), sandblasted and acid-etched zirconia (ZLA), polished titanium (PT) and polished zirconia (ZrP), and nanostructured disks (NTDs) were tested. Polished titanium disks were etched with a 1:1 combination of 98% H2SO4 and 30% H2O2 (piranha etching) for 5 h at room temperature to produce the NTDs. Atomic force microscopy was used to measure the surface topography, roughness, adhesion force, and work of adhesion. MTT assays and immunofluorescence staining were used to examine cell viability and adhesion after incubation of HGF-1 cells on the disk surfaces. After incubation with P. gingivalis, conventional culture, live/dead staining, and SEM were used to determine the antibacterial properties of NTD, SLA, ZLA, PT, and ZrP. RESULTS: Etching created nanocavities with 10-20-nm edge-to-edge diameters. Chemical etching increased the average surface roughness and decreased the surface adherence, while polishing and flattening of ZrP increased adhesion. However, only the NTDs inhibited biofilm formation and bacterial adherence. The NTDs showed antibacterial effects and P. gingivalis vitality reductions. The HGF-1 cells demonstrated greater viability on the NTDs compared to the controls. CONCLUSION: Nanocavities with 10-20-nm edge-to-edge diameters on titanium disks hindered P. gingivalis adhesion and supported the adhesion of gingival fibroblasts when compared to the surfaces of currently marketed titanium or zirconia dental implants. CLINICAL RELEVANCE: This study prepared an effective antibacterial nanoporous surface, assessed its effects against oral pathogens, and demonstrated that surface characteristics on a nanoscale level influenced oral pathogens and gingival fibroblasts. CLINICAL TRIAL REGISTRATION: not applicable.