Comparative Analysis of Endodontic 0.15 Stainless-Steel K-Files: Exploring Design, Composition, and Mechanical Performance.

To establish a glide path, smaller files (up to size 0.15) with tapers of 2% are commonly used as pathfinding files. They pre-shape the root canal space before transitioning to larger taper endodontic instruments, aiming to prevent procedural errors. This study aimed to compare the design, metal wire composition, and mechanical characteristics of seven different ISO size 15 stainless-steel hand files (K-File and C-File+). Ninety-one new stainless-steel ISO 15 K-files were mechanically tested. All files were inspected for deformations before the assessment. Dental operating microscope, scanning electron microscope (SEM), and optical microscope analyses were conducted on four randomly selected instruments from each group, and two instruments per group underwent an energy-dispersive X-ray spectroscopy (EDS) analysis. Buckling mechanical tests were performed using an Instron universal testing machine, and microhardness was assessed using a Vickers hardness tester. The statistical analysis employed the nonparametric Mood's median test, with a significance level set at 0.05. The instrument design analysis unveiled variations in the active blade area length and the number of spirals, while maintaining consistent cross-sections and symmetrical blades. Distinct tip geometries and surface irregularities were observed. While the energy-dispersive X-ray spectroscopy confirmed similar compositions, the buckling strength and microhardness values exhibited variability across for all tested files. Notably, the Dentsply ReadySteel C-File+ recorded the highest buckling value (2.10 N), and the Dentsply ReadySteel K-File exhibited the lowest (1.00 N) (p < 0.05). Moreover, the Dentsply ReadySteel K-File recorded the highest microhardness value (703 HVN), while the SybronEndo Triple-Flex had the lowest (549 HVN) (p < 0.05). While similarities in cross-section design and metal wire composition were noted among the files, variations in the number of spirals and mechanical performance were also observed. Thus, all of these factors should be considered when selecting suitable files for an efficient root canal treatment.

Bio-Piezoelectric Ceramic Composites for Electroactive Implants-Biological Performance.

Barium titanate (BaTiO3) piezoelectric ceramic may be a potential alternative for promoting osseointegration due to its piezoelectric properties similar to bone electric potentials generated in loading function. In this sense, the aim of this in vitro study was to evaluate the cellular response of human osteoblasts and gingival fibroblasts as well as the impact on S. oralis when in contact with BaTiO3 functionalized zirconia implant surfaces with piezoelectric properties. Zirconia discs with BaTiO3 were produced and contact poling (piezo activation) was performed. Osteoblasts (hFOB 1.19), fibroblasts (HGF hTERT) and S. oralis were culture on discs. Cell viability and morphology, cell differentiation markers, bacterial adhesion and growth were evaluated. The present study suggests that zirconia composite surfaces with the addition of piezoelectric BaTiO3 are not cytotoxic to peri-implant cells. Also, they seem to promote a faster initial osteoblast differentiation. Moreover, these surfaces may inhibit the growth of S. oralis by acting as a bacteriostatic agent over time. Although the piezoelectric properties do not affect the cellular inflammatory profile, they appear to enable the initial adhesion of bacteria, however this is not significant over the entire testing period. Furthermore, the addition of non-poled BaTiO3 to zirconia may have a potential reduction effect on IL-6 mediated-inflammatory activity in fibroblasts.

Accuracy of different digital acquisition methods in complete arch implant-supported prostheses: An in vitro study.

STATEMENT OF PROBLEM: Digital methods such as intraoral scanners for recording the location of implants supporting complete arch prostheses have limitations. Photogrammetry devices should be able to digitize implant positions accurately, but standardized comparisons between different digital acquisition methods are lacking. PURPOSE: The purpose of this in vitro study was to compare the repeatability of different digital acquisition methods for complete arch prostheses supported by 6 and 4 implants. MATERIAL AND METHODS: A master cast was created with 6 and 4 dental implants with multiunit abutments to obtain the master digital casts. The evaluated devices were the industrial high-resolution 12-megapixel scanner (reference) Atos Compact Scan 12M (GOM), the laboratory scanners D2000 (3Shape A/S) and S900 Arti (Zirkonzahn), the photogrammetry devices iCam (iMetric4D) and PIC (PIC Dental), and the intraoral scanners TRIOS 3 (3Shape A/S) and iTero Element 5D (Align Technology). The resulting files were imported to a computer-aided design software program (exocad GmbH) to obtain the implant replicas as standard tessellation language (STL) files. These files were imported into a software program (Geomagic Control X) and superimposed per group through the best-fit algorithm to determine repeatability, defined as the closeness of agreement between each group's scanned results as root mean square (RMS) values. The normality of distribution was tested by the Shapiro-Wilk normality test, and the Kruskal-Wallis test with adjustment with the Bonferroni correction method was used accordingly (α=.05). RESULTS: The repeatability means and 95% confidence intervals for the 4 implant scans were: 1.07 µm (0.86; 1.29) for GOM, 2.05 µm (1.89; 2.21) for D2000, 3.61 µm (3.23; 3.99) for S900, 7.01 µm (6.11; 7.91) for iCam, 5.18 µm (4.6; 5.76) for PIC, 20.52 µm (18.33; 22.72) for TRIOS3, and 20.5 µm (17.37; 23.63) for iTero. Statistically significant differences were found between devices, except for iCam versus PIC, GOM versus S900, iCam versus D2000, PIC versus D2000, and TRIOS3 versus iTero. The repeatability means and 95% confidence intervals for the 6 implant groups were: 1.36 µm (1.08; 1.65) for GOM, 3.17 µm (3.01; 3.33) for D2000, 2.15 µm (2.04; 2.25) for S900, 8.67 µm (8.06; 9.28) for iCam, 13.88 µm (12.62; 15.14) for PIC, 40.32 µm (36.29; 44.36) for TRIOS3, and 38.86 µm (34.01; 43.71) for iTero. Statistically significant differences were detected between devices, except for S900 versus GOM, PIC versus iCam, and iTero versus TRIOS 3. CONCLUSIONS: The results suggest that photogrammetry could be a suitable alternative for recording implant locations of complete arch prostheses supported by 4 or 6 implants, with better repeatability than intraoral scanners. Increasing the number of implants decreased the repeatability of every device tested except the laboratory scanners.

Wear of Titanium Implant Platforms with Different Abutment Connections and Abutment Materials: A Pilot Study.

The most commonly used material in dental implants and their abutments is titanium. Zirconia is a more aesthetic alternative to titanium abutments; however, it is much harder. There are concerns that zirconia could damage the surface of the implant over time, especially in less stable connections. The aim was to evaluate the wear of implants with different platforms connected to titanium and zirconia abutments. A total of six implants were evaluated, two of each connection type: external hexagon, tri-channel, and conical connections (n = 2). Half of the implants were connected to zirconia abutments, and the other half to titanium abutments (n = 3). The implants were then cyclically loaded. The implant platforms were evaluated by digital superimposing micro CT files and calculating the area of the loss surface (wear). In all the implants, a statistically significant loss of the surface area (p = 0.028) was observed when comparing the area before and after cyclic loading. The average lost surface area was 0.38 mm2 with titanium abutments and 0.41 mm2 with zirconia abutments. The average lost surface area was 0.41 mm2 with the external hexagon, 0.38 mm2 with the tri-channel, and 0.40 mm2 with the conical connection. In conclusion, the cyclic loads induced implant wear. However, neither the type of abutment (p = 0.700) nor the connection (p = 0.718) influenced the amount of surface area lost.

Metastasis of malignant tumors to the oral cavity: Systematic review of case reports and case series.

OBJECTIVE: To summarize published information regarding malignant tumors with metastasis to the oral cavity. MATERIALS AND METHODS: This was a systematic review with meta-analysis. An electronic search of Pubmed, Scopus, and Google Scholar databases from inceptions to February 2022 were performed. Only case reports or case series with histopathological results demonstrating metastasis to the oral cavity were included. The main outcomes included demographics, primary site, metastatic site, clinical manifestations, and patient survival. The quality of primary articles was assessed using the Joanna Briggs Institute - University of Adelaide scorecards for case reports and case series. Descriptive analysis and a Kaplan-Meier survival curve were performed. RESULTS: 273 articles were selected (50 case series and 223 case reports), for a total of 950 cases. The mean age was 57.11 years. Males were more affected (57.5%). The most common primary sites in women and men was breast (29.8%), and lung (24.8%), respectively. In ∼1/3 of the cases, oral metastasis preceded tumor dissemination. Jawbones were more affected (56.7%) than soft tissues (37.9%), with the mandible being the most affected site (45.5%), followed by the gingiva (19.9%). The most common clinical manifestation was a mass or nodule. Most radiographic evidence was radiolucency of the jaw (60.6%). 3-year and 5-year survival rates were 14.2 and 10.7%. In the majority of cases, the primary tumor was the first to be diagnosed, while in 30.4%, metastasis was the first sign of the disseminated disease. This can be implied that the oral metastasis should be included in the differential diagnosis list of the oral diseases. CONCLUSION: Clinicians should be aware of the possibility of, albeit uncommon, oral metastases. Because the extracted data in this review was relatively generalized, the investigators cannot develop the diagnostic clues of oral metastasis, which require further investigations.

Validation of a Portuguese version of the Groningen radiotherapy-induced xerostomia questionnaire

Background: The aim of this study was to validate and determine at pretest level the reliability of the Portuguese version of the Groningen radiotherapy-induced xerostomia questionnaire. Material and methods: This study employed 37 head and neck cancer patients. Each patient signed an informed consent and responded to the Portuguese version of the questionnaire in the form of an interview. This was repeated again after 2 weeks. A standard single question provided a validity check. Data were analyzed using Cronbach's α to test its reliability and total and interitem correlation, and intraclass correlation to determine its internal consistency and test-retest reliability. Construct validity supported by objective measurements as salivary secretion was also investigated. Significance was set at .05. Results: Cronbach's α was 0.91 and 0.89 for the first and second test administrations, respectively, which indicates that the internal consistency was excellent. The intraclass correlation coefficient value for the test-retest reliability was 0.70. The correlation between the total score of the questionnaire and standard single dry mouth question was 0.72 for the first round, indicating a good correlation. Conclusions: Demonstrating very good psychometric properties, the Portuguese version of the Groningen radiotherapy-induced xerostomia questionnaire is a valid tool and can be considered a reliable instrument to measure xerostomia in head and neck cancer patients. (AU)

Biomimetic Implant Surfaces and Their Role in Biological Integration-A Concise Review.

BACKGROUND: The increased use of dental implants in oral rehabilitation has been followed by the development of new biomaterials as well as improvements in the performance of biomaterials already in use. This triggers the need for appropriate analytical approaches to assess the biological and, ultimately, clinical benefits of these approaches. AIMS: To address the role of physical, chemical, mechanical, and biological characteristics in order to determine the critical parameters to improve biological responses and the long-term effectiveness of dental implant surfaces. DATA SOURCES AND METHODS: Web of Science, MEDLINE and Lilacs databases were searched for the last 30 years in English, Spanish and Portuguese idioms. RESULTS: Chemical composition, wettability, roughness, and topography of dental implant surfaces have all been linked to biological regulation in cell interactions, osseointegration, bone tissue and peri-implant mucosa preservation. CONCLUSION: Techniques involving subtractive and additive methods, especially those involving laser treatment or embedding of bioactive nanoparticles, have demonstrated promising results. However, the literature is heterogeneous regarding study design and methodology, which limits comparisons between studies and the definition of the critical determinants of optimal cell response.

Modification of Zirconia Implant Surfaces by Nd:YAG Laser Grooves: Does It Change Cell Behavior?

The aim of this study was to evaluate gingival fibroblasts and human osteoblasts' response to textured Nd:YAG laser microgrooves, with different dimensions, on zirconia implant surfaces. A total of 60 zirconia disks (8 mm in diameter and 2 mm in thickness) were produced and divided between four study groups (N = 15): three laser-textured (widths between 125.07 ± 5.29 µm and 45.36 ± 2.37 µm and depth values from 50.54 ± 2.48 µm to 23.01 ± 3.79 µm) and a control group without laser treatment. Human osteoblasts and gingival fibroblasts were cultured on these surfaces for 14 days. FEG-SEM (Field Emission Gun-Scanning Electron Microscope) images showed cellular adhesion at 24 h, with comparable morphology in all samples for both cell types. A similar cell spreading within the grooves and in the space between them was observed. Cell viability increased over time in all study groups; however, no differences were found between them. Additionally, proliferation, ALP (Alkaline phosphatase) activity, collagen type I, osteopontin and interleukin levels were not significantly different between any of the study groups for any of the cell types. Analysis of variance to compare parameters effect did not reveal statistically significant differences when comparing all groups in the different tests performed. The results obtained revealed similar cell behavior based on cell viability and differentiation on different microtopographic laser grooves, compared to a microtopography only established by sandblasting and acid-etching protocol, the reference surface treatment on zirconia dental implants.

Multimethod Assessment of Design, Metallurgical, and Mechanical Characteristics of Original and Counterfeit ProGlider Instruments.

A multimethod study was conducted to assess the differences between original (PG-OR) and counterfeit (PG-CF) ProGlider instruments regarding design, metallurgical features, and mechanical performance. Seventy PG-OR and PG-CF instruments (n = 35 per group) were evaluated regarding the number of spirals, helical angles, and measuring line position by stereomicroscopy, while blade symmetry, cross-section geometry, tip design, and surface were assessed by scanning electron microscopy. Energy-dispersive X-ray spectroscopy and differential scanning calorimetry were used to identify element ratio and phase transformation temperatures, while cyclic fatigue, torsional, and bending testing were employed to assess their mechanical performance. An unpaired t-test and nonparametric Mann−Whitney U test were used to compare instruments at a significance level of 5%. Similarities were observed in the number of spirals, helical angles, blade symmetry, cross-sectional geometries, and nickel−titanium ratios. Measuring lines were more reliable in the original instrument, while differences were noted in the geometry of the tips (sharper tip for the original and rounded for the counterfeit) and surface finishing with PG-CF presenting more surface irregularities. PG-OR showed significantly more time to fracture (118 s), a higher angle of rotation (440°), and a lower maximum bending load (146.3 gf) (p < 0.05) than PG-CF (p < 0.05); however, maximum torque was similar for both instruments (0.4 N.cm) (p > 0.05). Although the tested instruments had a similar design, the original ProGlider showed superior mechanical behavior. The results of counterfeit ProGlider instruments were unreliable and can be considered unsafe for glide path procedures.

Human Gingival Fibroblast and Osteoblast Behavior on Groove-Milled Zirconia Implant Surfaces.

Two type of cells representing periodontal hard tissues (osteoblasts) and soft tissues (fibroblasts) were evaluated in response to microgroove-milled zirconia surfaces. A total of 90 zirconia discs were randomly assigned to four width-standardized milling microgroove-textured groups and a control group without grooves (UT). The sandblast and acid-etch protocol were applied to all samples. Both cell lines were cultured on zirconia discs from 1 day up to 14 days. Cell morphology and adhesion were evaluated after 1 day of culturing. Cell viability and proliferation of the cells were measured. Alkaline phosphatase activity, collagen I, osteopontin, interleukin 1ß and interleukin 8 secretions were assessed at predefined times. The results obtained were presented in the form of bar graphs as means and standard deviations. Multi comparisons between groups were evaluated using two-away ANOVA or Mann−Whitney tests, and a p-value < 0.05 was established. Group comparisons with regard to cell viability, proliferation and secretion of collagen I, interleukin-1ß and interleukin 8 revealed no statistically significant differences. The alkaline phosphatase activity and osteopontin secretion were significantly higher in the group with a large groove compared to the small one and the control group. Nevertheless, the viability of gingival and bone cells did not appear to be affected by the milled microgroove texture compared to the conventional sandblasted and acid-etched texture, but they seem to influence osteoblasts' cellular differentiation.

Guided Bone Regeneration in the Edentulous Atrophic Maxilla Using Deproteinized Bovine Bone Mineral (DBBM) Combined with Platelet-Rich Fibrin (PRF)-A Prospective Study.

BACKGROUND: Bone regeneration procedures represent a major challenge in oral surgery. This study aimed to evaluate a composite PRF/particulate xenograft in guided bone regeneration. METHODS: Edentulous patients with horizontal ridge deficiencies in the anterior maxilla and candidates to an immediate-loading full-arch rehabilitation were included. Horizontal linear measurements indicating bone gain were assessed from computer beam computer tomography (CBCT) scans obtained at pre-surgery, post-surgery, and the 12-month follow-up. Mean bone values were presented as mean ± 95% CI. Non-parametric tests were used as appropriate, and the effect size was calculated with Cohen's d repeated measures. RESULTS: Eighteen patients were rehabilitated with 72 implants. The mean horizontal bone width was 4.47 [4.13-4.80] mm pre-surgically, 9.25 [8.76-9.75] mm post-surgically, and 7.71 [7.28-8.14] mm 12 months after. CONCLUSIONS: PRF associated with a xenograft seems to promote an effective horizontal bone gain. Randomized clinical trials are needed to confirm the benefits of this surgical approach.

Peri-implant cell response on groove and pore-textured zirconia surfaces.

OBJECTIVES: This study aimed to assess the independent influence of grooves and pores texturized by milling on gold-standard zirconia implant surfaces. METHODS: Milled groove and pore textured with equivalent width, depth, and spacing on zirconia discs were produced using press and sintering techniques. All samples were sandblasted and acid-etched (SBAE), and untextured discs were used as controls. Osteoblasts and fibroblasts were cultured on discs for 14 days. Field emission gun-scanning electron microscopy (FEG-SEM) was used to observe cellular adhesion and morphology. Cell viability and proliferation assays were performed. Additionally, alkaline phosphatase activity, collagen type I, and osteopontin were evaluated at pre-defined time points. Results are presented as mean and standard deviation (SD), group comparisons were tested using one-way ANOVA (Tukey's post-hoc), and significance was set at P < 0.05. RESULTS: FEG-SEM images revealed cellular adhesion at 24 h in all samples with differences in distribution. Although both cell lines showed increased cell viability and differentiation cell markers such as collagen and osteopontin over time, statistically significant differences between groups were found in none of the quantitative study variables (P > 0.05). CONCLUSION: The results suggest similar cellular behavior between different patterns with similar dimensions and between them and microtopography by SBAE protocol currently used as the gold-standard for zirconia dental implants. The addition of pore and groove microtextures to the gold-standard zirconia dental implant surfaces treated with SBAE does not seem to be an asset in the cellular behavior of the hard and soft tissue cells.

Multimethod Assessment of the Cyclic Fatigue Strength of ProGlider, Edge Glide Path and R-Pilot Endodontic Instruments.

BACKGROUND: The aim of this study was to comprehensively evaluate the cyclic fatigue strength of ProGlider, Edge Glide Path, and R-Pilot instruments. METHODS: Sixty-three instruments were submitted to a multimethod evaluation. Their design was analyzed by stereomicroscopy and scanning electron microscopy, including the number of blades, helical angle means, cross-sectional design, surface finishing, and symmetry. Energy-dispersive X-ray spectroscopy was used determine the nickel/titanium elements ratio, and differential scanning calorimetry determined the instruments' phase transformation temperatures. The cyclic fatigue tests were conducted in an artificial canal with a 6 mm radius and 86 degrees of curvature. The Mood's median test and one-way ANOVA were used to determine differences, with the significance level set at 0.05. RESULTS: The ProGlider presented the highest number of blades (n = 21), while R-Pilot had the highest helical angles (26.4°). Differences were noted in the instruments' cross-sections and surface finishing. The ProGlider and R-Pilot showed some similarities regarding the phase transformation temperatures but differed from the Edge Glide Path. All alloys showed an almost equiatomic nickel/titanium ratio. The R-Pilot instruments showed a significantly higher (p < 0.05) time to fracture than both the other files. CONCLUSION: Reciprocating R-Pilot instruments showed a higher cyclic fatigue time to fracture than the ProGlider and Edge Glide Path rotary files.

Design and surface characterization of micropatterned silica coatings for zirconia dental implants.

The use of zirconia as an alternative biomaterial for titanium implants has been increasing due to its biocompatibility, favorable aesthetic features, less potential for early plaque accumulation and mechanical properties. Despite the developed efforts, strategies to promote an effective osseointegration are still enough. In this sense and combining the silica properties to improve bone formation with the micropatterning guidance characteristics, silica coatings with micropatterns were designed and evaluated regarding their hydrophilicity and integrity through resistance to scratch and friction tests against femoral bone plates (simulating implant insertion). A combined sol-gel and soft-lithography techniques were used to produce silica coatings onto zirconia substrates and different techniques were used to characterize the micropatterned silica coatings. The results revealed that the production of lines and pillars micropatterns increases the surface roughness (Ra values) and improves the surface strength adhesion. Through the scratch test, it was possible to verify that the integrity and topography characteristics of all micropatterned coatings were not significantly affected after the friction test meaning that their function is not compromised after implant insertion. Additionally, the lines micropattern was the one that presented the highest hydrophilicity for distilled water, thus being a promising surface to promote improved osseointegration. The combined use of different surface micropatterns could potentially be used to guide bone apposition and avoiding peri-implantitis.

Oral biopsies in a Portuguese population: A 20-year clinicopathological study in a university clinic.

Background: Performing a biopsy is very important in oral medicine and the anatomopathological examination is fundamental to obtain or to confirm the diagnosis in oral and maxillofacial pathology. The purpose of this study is to analyse the frequency and characteristic patterns of biopsied oromaxillofacial lesions in a Portuguese population. Material and Methods: A descriptive statistical analysis of the data from the anatomopathological reports of the biopsies performed between 1999 and 2019 at the university clinic of the Faculty of Dental Medicine of the University of Lisbon was performed, regarding the patient's gender and age, type of biopsy, location of lesions, clinical and histological diagnosis, and the results were obtained. Association relationships were studied using the chi-square test and the Kruskal-Wallis test to correlate variables. P<0.05 was considered statistically significant. Results: From a total sample of 1448 patients, 826 (57.1%) were female, 610 (42.1%) were male, and 12 (0.8%) had no gender information, with a mean age of 50.14 years (standard deviation ± 17.61). The preferred location was the buccal mucosa, vestibule fundus and alveolar mucosa (20.7%). Benign lesions (BL) were the most common, in 82,8% of the cases, followed by oral potentially malignant disorders (OPMD) in 15,5%, and finally, malignant lesions (ML) in 1.7%. Focal fibrous hyperplasia was the most frequent diagnosis in the total sample (25.6%). In the young group, the most common entity was mucocele (34.0%), with a predominance of the lower lip (32.9%). In OPMD, leukoplakia was the most frequently diagnosed (48,7%). The most common ML was squamous cell carcinoma (92.0%), appearing mainly in the tongue (34.8%). A statistically significant relation between ML and older age was found. Conclusions: This study included biopsies analysed over a period of 20 years, being BL the main pathology to affect the oral cavity. Although less frequent, OPMD and ML should not be neglected and must be correctly diagnosed and treated. Key words:Oral biopsies, Oral and maxillofacial pathology, Oral medicine, Clinicopathological analysis, Epidemiological study, University clinic.

Laser surface treatment on Yttria-stabilized zirconia dental implants: Influence on cell behavior.

Yttria-stabilized zirconia (YSZ) is being proposed as an alternative material to Titanium for dental implants due to its aesthetic and biocompatibility properties. However, is it yet to define the optimal surface treatment to improve YSZ bioactivy. Texturization is a promising approach, but the biological role of patterned YSZ surfaces in cell cultures is yet to be determined. Thus, cellular behavior of osteoblasts and fibroblasts in contact with groove-texturized YSZ surfaces was investigated. YSZ discs were groove-textured by conventional milling and Nd:YAG laser. All samples including control were sandblasted and acid-etched. Human osteoblasts and fibroblasts were cultured on discs for 14 days. Morphology and cellular adhesion were observed. Cell viability, interleukin-1ß, osteopontin, collagen type I prodution, alkaline phosphatase activity, and interleukin-8 were measured. YSZ texturization by conventional milling improved osteoblasts viability and differentiation when compared to laser texturization. Fibroblasts behavior did not seem to be influenced by the texturing technique. Compared to sandblasting and acid etching currently used as gold standard for zirconia dental implants no superiority of macrotexturization was found.

Implant Survival in Immediately Loaded Full-Arch Rehabilitations Following an Anatomical Classification System-A Retrospective Study in 1200 Edentulous Jaws.

This retrospective study analyzed implant survival of immediate implant-supported fixed complete denture (IFCD) treatment options (TOs) based on the level of alveolar atrophy (CC). Records of 882 patients receiving a total of 6042 implants at one private referral clinic between 2004 and 2020 were considered. The mean follow-up period was 3.8 ± 2.7 years. Cumulative implant survival rates (CSRs) were analyzed as a function of CCs and TOs according to Mantel-Haenszel and Mantel-Cox. Hazard risk ratios for implant loss were compared using Cox regression. Confounding factors were identified using mixed Cox regression models. The 2- and 5-year CSRs were 98.2% and 97.9%, respectively. Maxillary 2- and 5-year CSRs were lower (97.7% and 97.3%) compared to mandibular CSRs (99.8% and 98.6%) (p = 0.030 and 0.0020, respectively). The CC did not influence CSRs of IFCDs in the mandible (p = 0.1483 and 0.3014, respectively) but only in the maxilla (p = 0.0147 and 0.0111), where CSRs decreased with increasing atrophy. TOs did not statistically differ in terms of survival rate for a given level of alveolar atrophy. The adaption of IFCD treatments to the level of atrophy and patient-specific risk factors can result in high CSRs, even at different levels of bone atrophy.

Is the timing of implant placement and loading influencing esthetic outcomes in single-tooth implants?-A systematic review.

OBJECTIVES: To address the following question: "Is the timing of implant placement and/or loading influencing the esthetic outcomes of implant-supported single crowns?" MATERIAL AND METHODS: A literature screening was performed in four electronic databases until June 2020. Randomized controlled clinical trials with a minimum of 10 patients and 1 year of follow-up and reporting on dimensional changes of the peri-implant mucosa (midfacial recession, papilla level) and esthetic indexes were included. Cochrane Risk of Bias Tool was used, and comparable trials were subjected to meta-analyses. RESULTS: Out of 8549 articles, 72 full-text articles were assessed for eligibility and 18 were included. Nine trials evaluated the timing of implant placement, and nine trials evaluated the timing of loading. The included trials comparing immediate implant placement to delayed implant placement evaluating the midfacial recession reported heterogeneous findings. No differences were found at 1 and 2-years, when comparing midfacial recession and papilla level between immediate and early implant placement. In immediate and delayed implant placement, when comparing conventional and immediate loading, the midfacial mucosal margin change was not statistically significant at the 1-year follow-up. When evaluating the timing of implant placement and/or loading the included trials found no differences in the Pink Esthetic score, White Esthetic score, and Papilla Index between groups. CONCLUSIONS: Both immediate and early implant placement protocols presented stable treatment results in terms of esthetic outcomes at the 1-, 2-, and 10-years follow-up. Loading protocols did not seem to influence esthetic outcomes in short- and medium-term follow-ups.

Facial scanner accuracy with different superimposition methods - In vivo study.

PURPOSE: To compare trueness and precision between conventional and digital facial measurements and to evaluate the accuracy of different superimposition techniques for facial scans. MATERIALS AND METHODS: Twenty volunteers were recruited. Predetermined facial landmarks were marked with a black pen, and the interlandmark distances were measured manually with a conventional caliper and digitally with Geomagic software. Two consecutive facial scans were performed and superimposed using as best-fit reference the full face, the face without the eyes, and the bone-supported areas (eg, forehead and zygomatic areas) in order to assess root mean square (RMS) differences. Trueness and precision were evaluated and compared between the conventional and digital techniques. Mann-Whitney U and Kruskal-Wallis post hoc tests were used. The significance level was established at α = .05. RESULTS: Trueness between conventional and digital measurements was 1,151.75 ± 1,265.52 µm (3.04% ± 4.82%), and precision was 322.31 ± 300.54 µm (0.93% ± 1.10%). Global mean RMS values for each superimposition technique were 334.15 ± 172.07 for the full face, 339.57 ± 173.13 for the face without the eyes, and 385.65 ± 182.29 for the bone-supported areas, with the latter presenting statistically significant differences compared to the other two. CONCLUSION: Although statistically significant differences were detected in facial measurements, they were below the clinically detectable threshold. Superimposition with the full face and the face without the eyes area presented smaller discrepancies than with the bone-supported areas, with higher discrepancies in the lower third of the face.

Bioactive-Enhanced Polyetheretherketone Dental Implant Materials: Mechanical Characterization and Cellular Responses.

The aim of this study was to characterize the mechanical properties of a bioactive-modified polyetheretherketone (PEEK) manufacturing approach for dental implants and to compare the in vitro biological behavior with titanium alloy (Ti6Al4V) as the reference. PEEK, PEEK with 5% hydroxyapatite (HA), PEEK with 5% beta-tricalcium phosphate (ßTCP), and Ti6Al4V discs were produced using hot pressing technology to create a functionally graded material (FGM). Surface roughness values (Ra, Rz), water contact angle, shear bond strength, and Vickers hardness tests were performed. Human osteoblasts and gingival fibroblasts bioactivity was evaluated by a resazurin-based method, alkaline phosphatase activity (ALP), and confocal laser scanning microscopy (CLSM) images of fluorescent-stained fibroblasts. Morphology and cellular adhesion were confirmed using field emission gun-scanning electron microscopy (FEG-SEM). Group comparisons were tested using analysis of variance (Tukey post hoc test), α = .05. All groups presented similar roughness values (P > .05). Ti6Al4V group was found to have the highest contact angle (P < .05). Shear bond strength and Vickers hardness of different PEEK materials were similar (P > .05); however, the mean values in the Ti6Al4V group were significantly higher when compared with those of the other groups (P < .05). Cell viability and proliferation of osteoblast and fibroblast cells were higher in the PEEK group (P < .05). PEEK-ßTCP showed the highest significant ALP activity over time (P < .05 at 14 days of culture). An enhanced bone and soft-tissue cell behavior on pure PEEK was obtained to the gold standard (Ti6Al4V) with equivalent roughness. The results substantiate the potential role of chemical composition rather than physical properties of materials in biological responses. The addition of 5% HA or ßTCP by FGM did not enhance PEEK mechanical properties or periodontal cell behavior.