Segmentation of process-related contaminations on two-piece abutments using pixel-based machine learning: a new quantification approach?

PURPOSE: A reference method for quantifying contaminations on two-piece abutments manufactured using CAD/CAM has not yet been established. In the present in vitro study, a pixel--based machine learning (ML) method for detecting contamination on customized two-piece abutments was investigated and embedded in a semiautomated quantification pipeline. MATERIALS AND METHODS: Forty-nine CAD/CAM zirconia abutments were fabricated and bonded to a prefabricated titanium base. All samples were analyzed for contamination by scanning electron microscopy (SEM) imaging followed by pixel--based ML and thresholding (SW) for contamination detection; quantification was performed in the postprocessing pipeline. Wilcoxon signed-rank test and Bland-Altmann plot were applied to compare both methods. The contaminated area fraction was recorded as a percentage. RESULTS: There was no statistically significant difference between the percentages of contamination areas (median = 0.004) measured with ML (median = 0.008) and with SW (median = 0.012), asymptotic Wilcoxon test: P = 0.22. The Bland-Altmann plot demonstrated a mean difference of -0.006% (95% confidence interval [CI] from -0.011% to 0.0001%) with increased values from a contamination area fraction of > 0.03% for ML. CONCLUSION: Both segmentation methods showed comparable results in evaluating surface cleanliness; pixel-based ML is a promising assessment tool for detecting external contaminations on zirconia abutments. Further studies are required to investigate the clinical performance of this tool.

Influence of exposure of customized dental implant abutments to different cleaning procedures: an in vitro study using AI-assisted SEM/EDS analysis.

PURPOSE: Dental implant abutments are defined as medical devices by their intended use. Surfaces of custom-made CAD/CAM two-piece abutments may become contaminated during the manufacturing process in the dental lab. Inadequate reprocessing prior to patient care may contribute to implant-associated complications. Risk-adapted hygiene management is required to meet the requirements for medical devices. METHODS: A total of 49 CAD/CAM-manufactured zirconia copings were bonded to prefabricated titanium bases. One group was bonded, polished, and cleaned separately in dental laboratories throughout Germany (LA). Another group was left untreated (NC). Five groups received the following hygiene regimen: three-stage ultrasonic cleaning (CP and FP), steam (SC), argon-oxygen plasma (PL), and simple ultrasonic cleaning (UD). Contaminants were detected using scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDS) and segmented and quantified using interactive machine learning (ML) and thresholding (SW). The data were statistically analysed using non-parametric tests (Kruskal-Wallis test, Dunn's test). RESULTS: Significant differences in contamination levels with the different cleaning procedures were found (p ≤ 0.01). The FP-NC/LA groups showed the most significant difference in contamination levels for both measurement methods (ML, SW), followed by CP-LA/NC and UD-LA/NC for SW and CP-LA/NC and PL-LA/NC for ML (p ≤ 0.05). EDS revealed organic contamination in all specimens; traces of aluminum, silicon, and calcium were detected. CONCLUSIONS: Chemothermal cleaning methods based on ultrasound and argon-oxygen plasma effectively removed process-related contamination from zirconia surfaces. Machine learning is a promising assessment tool for quantifying and monitoring external contamination on zirconia abutments.

Peri-implantitis and the Effect of the Implant Surface at Placement.

Modern root-form endosseous dental implants have been used to successfully replace missing teeth for more than four decades. The implant industry has grown substantially during this time, with many hundreds of dental implant manufacturers providing components for clinicians around the globe. Increased acceptance of dental implants has greatly amplified the number of dental implants placed worldwide. As the dental implant patient population continues to age, long-term follow-up after implant placement has become increasingly important due to various factors associated with the condition and maintenance of implants placed. Although dental implants exhibit a high success rate as a medical device, their life expectancy may be limited depending on the patient's changing health, use of medications, lifestyle changes, nutrition, occlusal/bite issues, loss of additional teeth, experiences of trauma, lack of sufficient keratinized soft tissue, loss of bony support, and oral hygiene habits. When loss of soft-tissue coverage and/or bone occurs, the resultant inflammation surrounding the implant is known as peri-implantitis.

Influence of cold atmospheric plasma on dental implant materials - an in vitro analysis.

BACKGROUND AND OBJECTIVES: Alterations in the microenvironment of implant surfaces could influence the cellular crosstalk and adhesion patterns of dental implant materials. Cold plasma has been described to have an influence on cells, tissues, and biomaterials. Hence, the mechanisms of osseointegration may be altered by non-thermal plasma treatment depending on different chemical compositions and surface coatings of the biomaterial. The aim of the present study is to investigate the influence of cold atmospheric plasma (CAP) treatment on implant surfaces and its biological and physicochemical side effects. MATERIALS AND METHODS: Dental implant discs from titanium and zirconia with different surface modifications were treated with CAP at various durations. Cell behavior and adhesion patterns of human gingival fibroblast (HGF-1) and osteoblast-like cells (MG-63) were examined using scanning electron microscopy and fluorescence microscopy. Surface chemical characterization was analyzed using energy-dispersive X-ray spectroscopy (EDS). Quantitative analysis of cell adhesion, proliferation, and extracellular matrix formation was conducted including real-time PCR. RESULTS: CAP did not affect the elemental composition of different dental implant materials. Additionally, markers for cell proliferation, extracellular matrix formation, and cell adhesion were differently regulated depending on the application time of CAP treatment in MG-63 cells and gingival fibroblasts. CONCLUSIONS: CAP application is beneficial for dental implant materials to allow for faster proliferation and adhesion of cells from the surrounding tissue on both titanium and zirconia implant surfaces with different surface properties. CLINICAL RELEVANCE: The healing capacity provided through CAP treatment could enhance osseointegration of dental implants and has the potential to serve as an effective treatment option in periimplantitis therapy.

Quality Assessment of Five Randomly Chosen Ceramic Oral Implant Systems: Cleanliness, Surface Topography, and Clinical Documentation.

PURPOSE: After some initial setbacks in the 1970s, ceramic implants seem to be a promising alternative to titanium implants. Since the surface of an implant system represents the interface to surrounding biologic structures, the study focuses on cleanliness and surface topography. Clinical documentation of the corresponding systems completes the picture and allows a better evaluation of zirconia implant systems. MATERIALS AND METHODS: Five different ceramic implant systems were selected randomly and purchased via blind-shopping: Z5s (Z-Systems), ZiBone (COHO), W implant (TAVDental), ceramic. implant (vitaclinical), and BioWin!/Standard Zirkon Implantat (Champions-Implants/ZV3 system). Three samples of each implant system underwent scanning electron microscopy (SEM) imaging and elemental analysis (EDS). Where appropriate, subsequent Time-of-Flight Secondary Ion Mass Spectrometry (ToF-SIMS) was performed to identify the chemical nature of impurities. Surface topography was evaluated, and a search for clinical trials in the PubMed database, on the websites and by written request to each dental implant manufacturer, was performed. RESULTS: Surfaces of Champions implants (ZV3) and Z-Systems implants were relatively clean, whereas the other investigated surfaces of vitaclinical, TAV Dental, and ZiBone implants all displayed organic contaminations on their surfaces. Four of the investigated ceramic implants showed a moderately rough implant surface. Only the vitaclinical ceramic.implant had minimal surface roughness. Three ceramic designs-vitaclinical, ZV3, and Z-Systems-had clinical trials documented with up to 3 years of follow-up and results varying between 82.5% and 100% survival. TAV Dental W and ZiBone implant systems lacked properly conducted clinical recording of results. CONCLUSION: The results of this study showed that it is technically possible to produce zirconia implants that are largely residue-free. On the other hand, the variety of significant residues found in this analysis raises concerns, as contamination may lead to undesirable biologic effects. The lack of clinical studies in peer-reviewed journals does not seem to be relevant for the approval of marketing, nor does the lack of surface cleanliness. In the authors' opinion, a critical analysis of these aspects should be included in a more stringent future analysis prior to the marketing of oral implant systems.

Qualitative and Semi-Quantitative Assessment of Processing-Related Surface Contamination of One- and Two-Piece CAD/CAM Abutments before and after Ultrasonic Cleaning.

Manufacturing processes of custom implant abutments may contaminate their surfaces with micro wear deposits and generic pollutants. Such particulate debris, if not removed, might be detrimental and provoke inflammatory reactions in peri-implant tissues. Although regulatory guidelines for adequate cleaning, disinfection, or sterilization exist, there does not appear to be a consistent application and data on the amount and extent of such contaminants is lacking. The aim of the present in vitro study was to evaluate the quality and quantity of processing-related surface contamination of computer-aided design/computer-aided manufacturing (CAD/CAM) abutments in the state of delivery and after ultrasonic cleaning. A total of 28 CAD/CAM monotype and hybrid abutments were cleaned and disinfected applying a three-stage ultrasonic protocol (Finevo protocol). Before and after cleaning, the chemical composition and the contamination of the abutments were assessed using scanning electron microscopy (SEM), dispersive X-ray spectroscopy (EDX), and computer-aided planimetric measurement (CAPM). In the delivery condition, monotype abutments showed a significantly higher amount of debris compared to hybrid abutments (4.86 ± 6.10% vs. 0.03 ± 0.03%, p < 0.001). The polishing process applied in the laboratory after bonding the hybrid abutment components reduces the surface roughness and thus contributes substantially to their purity. The extent of contamination caused by computer-aided manufacturing of custom abutments can be substantially minimized using a three-stage ultrasonic protocol.

On the Cleanliness of Different Oral Implant Systems: A Pilot Study.

(1) Background: This paper aimed to compare the cleanliness of clinically well-documented implant systems with implants providing very similar designs. The hypothesis was that three well-established implant systems from Dentsply Implants, Straumann, and Nobel Biocare were not only produced with a higher level of surface cleanliness but also provided significantly more comprehensive published clinical documentation than their correspondent look-alike implants from Cumdente, Bioconcept, and Biodenta, which show similar geometry and surface structure. (2) Methods: Implants were analyzed using SEM imaging and energy-dispersive X-ray spectroscopy to determine the elemental composition of potential impurities. A search for clinical trials was carried out in the PubMed database and by reaching out to the corresponding manufacturer. (3) Results: In comparison to their corresponding look-alikes, all implants of the original manufacturers showed-within the scope of this analysis-a surface free of foreign materials and reliable clinical documentation, while the SEM analysis revealed significant impurities on all look-alike implants such as organic residues and unintended metal particles of iron or aluminum. Other than case reports, the look-alike implant manufacturers provided no reports of clinical documentation. (4) Conclusions: In contrast to the original implants of market-leading manufacturers, the analyzed look-alike implants showed significant impurities, underlining the need for periodic reviews of sterile packaged medical devices and their clinical documentation.

The Influence of an Ultrasonic Cleaning Protocol for CAD/CAM Abutment Surfaces on Cell Viability and Inflammatory Response In Vitro.

BACKGROUND/AIM: To evaluate the effect of an ultrasonic cleaning and disinfection method for CAD/CAM abutment surfaces on cell viability and inflammatory response in vitro. MATERIALS AND METHODS: Untreated and manually polished surfaces of CAD/CAM generated titanium and zirconia disks were randomly assigned, either to a 3-step ultrasonic cleaning and disinfection process (test: TiUF, TiPF, ZrUF, ZrPF) or to 30 sec steam cleaning (control: TiUS, TiPS, ZrUS, ZrPS). Pre-cleaning surface analyses using scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDX), and surface profilometry were performed. Human gingival fibroblasts (HGFs) were cultured on test and control specimens and subsequently examined for cell viability and inflammatory response. Expression of acute inflammatory cytokine interleukin (IL)-6 and vascular endothelial growth factor A (VEGFA) were assessed by means of RT-qPCR. RESULTS: Cells on all specimens exhibited a satisfactory viability, indicating firm attachment. Cells on polished zirconia samples, cleaned by means of sonication (ZrPF), exhibited significantly higher viability than cells on the same material cleaned by steam (ZrPS), p=0.019. For all other three material/ surface treatment combinations (TiU, TiP, ZrU), no such difference was observed between the cleaning methods. The messenger ribonucleic acid (mRNA) levels of IL-6 and VEGFA were between 50 and 105% of that of the control cells on the non-toxic control surface. mRNA levels of IL-6 and VEGFA correlated well with each other. CONCLUSION: Except for higher viability of cells cultured on polished zirconia specimens, no universally applicable advantage could be found for the ultrasonic cleaning procedure for zirconia and titanium abutment surfaces regarding cell viability, IL-6 expression or VEGFA expression. The cleaning procedures did not have any negative effect either.

Influence of scaling procedures on the integrity of titanium nitride coated CAD/CAM abutments.

PURPOSE: To determine the extent of treatment traces, the roughness depth, and the quantity of titanium nitride (TiN) removed from the surface of CAD/CAM abutments after treatment with various instruments. MATERIALS AND METHODS: Twelve TiN coated CAD/CAM abutments were investigated for an in vitro study. In the test group (9), each abutment surface was subjected twice (150 g vs. 200 g pressure) to standardized treatment in a simulated prophylaxis measure with the following instruments: acrylic scaler, titanium curette, and ultrasonic scaler with steel tip. Three abutments were used as control group. Average surface roughness (Sa) and developed interfacial area ratio (Sdr) of treated and untreated surfaces were measured with a profilometer. The extent of treatment traces were analyzed by scanning electron microscopy. RESULTS: Manipulation with ultrasonic scalers resulted in a significant increase of average surface roughness (Sa, P<.05) and developed interfacial area ratio (Sdr, P<.018). Variable contact pressure did not yield any statistically significant difference on Sa-values for all instruments (P=.8). Ultrasonic treatment resulted in pronounced surface traces and partially detachment of the TiN coating. While titanium curettes caused predominantly moderate treatment traces, no traces or detectable substance removal has been determined after manipulation with acrylic curettes. CONCLUSION: Inappropriate instruments during regular plaque control may have an adverse effect on the integrity of the TiN coating of CAD/CAM abutments. To prevent defects and an increased surface roughness at the transmucosal zone of TiN abutments, only acrylic scaling instruments can be recommended for regular maintenance care.

Análise qualitativa do interior de imperfeições presentes em 5 marcas de implantes brasileiros por microscopia eletrônica de varredura e espectroscopia por energia dispersiva / Qualitative analysis of inner imperfections present in 5 brands of brazilian dental implants by scanning electron microscopy and dispersive energy spectroscopy

O titânio é um dos 10 mais comuns elementos da terra, existem diferentes pesos atômicos, isótopos estáveis e radioisótopos conhecidos, está presente em ligas comerciais e semicomerciais, sendo que o titânio puro apresenta diferentes graus de pureza. Além disso, as ligas possuem classificações que agregam outros elementos neutros e/ou estabilizadores, são submetidas a diferentes tipos de tratamento de superfícies. Na fabricação dos implantes, o processo industrial da extração da rocha até a colocação na boca pode corromper o grau de pureza. A proposta do presente estudo foi avaliar qualitativamente buracos presentes em 5 implantes dentários brasileiros. As amostras foram preparadas em resina acrílica e realizados cortes sagitais com lâmina de diamante e analisadas no Microscópio Eletrônico de Varredura TM 3030 PLUS TABLESTOP MICROSCOPE HITACHI e reanalisadas no Microscópio Fei Quanta 400. Os resultados evidenciaram que os implantes apresentaram impurezas e estas impurezas podem ser os estabilizadores ou elementos neutros presentes no titânio ou nas ligas utilizadas. Implantodontistas devem ficar alertas sobre a qualidade do implante

Titanium is one of the 10 most common elements of the earth, there are different atomic weights, stable isotopes and known radioisotopes, it is present in commercial and semi-commercial alloys and pure titanium has different degrees of purity. In addition, alloys have classifications that add other neutral elements and/or stabi¬lizers, they are submitted to different types of surface treatments. In manufacturing the implants, the industrial process of extracting the rock into the mouth can corrupt the degree of purity. The purpose of the present study was to qualitatively evaluate holes present in 5 Brazilian dental implants. The samples were prepared in acrylic resin and sagittal cuts with diamond blade and analyzed in the Scanning Electron Microscope TM 3030 PLUS TABLESTOP MICROSCOPE HITACHI and Fei quanta 400. The results showed that the implants presented impurities and these impurities may be the stabilizers or neutral elements present in the titanium or the alloys used. Implant dentists should be alert to the quality of the implant

Análise qualitativa da estrutura química de quatro marcas comerciais de implantes dentários brasileiros: Estudo-piloto / Qualitative analysis of the chemical composition of four Brazilian dental implant manufacturers: a pilot study

Objetivo: avaliar qualitativamente a estrutura química de quatro marcas comerciais de implantes dentários brasileiros. Material e métodos: 12 amostras de diferentes lotes foram fixadas em resina acrílica usando um processo padronizado, e cortes sagitais foram realizados. As amostras foram analisadas em dois microscópios eletrônicos de varredura (FEI Quanta 400, TM 3030 Plus Tablestop Microscope Hitachi). Resultados: a maioria apresentou na sua porção interna (8 das 12) diferentes níveis de níquel, variando de uma marca para outra. Entretanto, este metal não foi detectado na superfície externa. A presença de níquel talvez seja atribuída às matérias-primas e metodologia de produção, desde a sua extração até a comercialização. Conclusão: dentro dos limites desta investigação, há necessidade de mais estudos qualitativos, em todo o processo de fabricação de todos os implantes comercializados, assim como estudos quantitativos com relação ao elemento níquel nos implantes dentários.

Objective: to perform a qualitative evaluation of the chemical structure of four commercial dental implant Brazilian brands. Material and methods: 12 samples of different batches were embedded in acrylic resin according to a standardized process, and sagittal sections were made accordingly. All the samples were analyzed under two SEM devices (FEI Quanta 400, TM 3030 Plus Tablestop Microscope Hitachi). Results: most samples (8 of 12) revealed at their internal portions different levels of Nickel, from one manufacturer to the other. However, this metal was not detected at the external implant portion. The presence of Nickel maybe can be attributed to the raw materials and production process, from extraction to commercialization. Conclusion: within the limits of this investigation, more qualitative studies are necessary throughout the fabrication process of all investigated implants in the market, as well as quantitative evaluations regarding the presence of Nickel on dental implants.