Single-piece zirconia versus single-piece titanium, narrow-diameter dental implants in the anterior maxilla: 5-year post-loading results of a randomized clinical trial.

OBJECTIVES: The aim of this study was to evaluate esthetic parameters in the anterior maxillary region by comparing single-piece zirconia versus titanium narrow-diameter implants. Additionally, clinical, radiological and patient-reported outcome measures (PROMs) were analyzed. MATERIALS AND METHODS: Thirty implants (tissue level implant) were placed in 30 patients in the maxillary esthetic sector. Depending on randomization, a zirconia (test) or titanium implant (control) was placed. Esthetic, clinical, and radiological parameters, including the implant crown esthetic index (ICAI), pink esthetic score (PES), probing pocket depth, bleeding on probing, plaque index, and marginal bone levels, were evaluated at 12, 36 and 60 months after loading. RESULTS: Sixty months after crown placement, no significant differences were found between groups. The ICAI values were 5.25 ± 4.21 and 4.50 ± 2.98 for the test and control groups, respectively. The corresponding PES values were 7.44 ± 1.93 and 7.43 ± 1.74 for the test and control groups, respectively. There were no significant intergroup differences for the rest of the parameters evaluated. CONCLUSION: It can be suggested that monotype zirconia implants may serve as a potential alternative to titanium implants in selected clinical scenarios. While the results demonstrated comparable esthetic, clinical, and radiological aspects for zirconia implants as compared to titanium implants after a 5-year follow-up period, further research with larger sample sizes and longer-term follow-up is recommended.

Clinical Performance of 170 Frictional Morse Taper Implants: 2 Years Follow-Up.

This study evaluated the clinical survival rates of 170 Morse taper implants through clinical and mechanical parameters in different therapeutic approaches such as single crowns, fixed partial prostheses, and fixed full-arch prostheses. Patients referred to the Center on Education and Research on Dental Implants from May 2017 to July 2018 with the indication for dental implant therapy, aged >18 years, without periodontal disease, recent evidence of inflammatory activity or other oral disorders, current pregnancy, uncontrolled diabetes mellitus or heavy smoking habit were included in this study. After 12 weeks of healing since the implants were placed in the mandible and after 16 weeks following implants placed in the maxilla, patients returned to the Center for prosthetic rehabilitation. After implant therapy, all patients underwent periodical, clinical, and prosthetic examinations every 6 months. Prosthetic restorations involved 109 fixed reconstructions in function. Few prosthetic complications were reported (6.55%). Twenty implants were rehabilitated with cemented prostheses; from those, 1 crown suffered a loss in retention/decementation. Of the 148 implants rehabilitated with screwed-retained prostheses, 6.76% suffered prosthetic screw loosening. The cumulative implant survival rate was 98.2%. When peri-implant tissue health was evaluated, the keratinized mucosa band appeared related to peri-implant tissue stability. Thus, Morse taper implants represented a successful procedure for implant rehabilitation, with a high cumulative implant survival rate, low prevalence of biological and prosthetic complications, and good stability of peri-implant tissues over the assessed period.

Efficacy of alveolar ridge preservation with xenografts and resorbable socket sealing materials in the esthetic region: A systematic review with meta-analyses.

AIM: The present systematic review aimed to identify and summarize the clinical, radiographic, and histological outcomes of alveolar ridge preservation using bone xenografts and absorbable sealing materials compared with spontaneous healing in the esthetic zone. MATERIALS AND METHODS: Randomized clinical trials (RCTs) fulfilling specific eligibility criteria were included. Two review authors independently searched for eligible studies, extracted data from the published reports and performed the risk of bias assessment (RoB 2 tool). Study results were summarized using random effects meta-analyses. RESULTS: Thirteen articles concerning 10 RCTs were included, involving a total of 357 participants. Most of studies were considered as "low" risk of bias. Meta-analyses indicated less horizontal (difference in means-MD = 1.88 mm; p < 0.001), vertical mid-buccal (MD = 1.84 mm; p < 0.001) and vertical mid-lingual (MD = 2.27 mm; p < 0.001) bone resorption in alveolar ridge preservation compared to spontaneous healing as assessed clinically. Bone changes assessed radiographically showed consistent results in terms of horizontal (at 1 mm: MD = 1.84 mm, p < 0.001), vertical mid-buccal (MD = 0.95 mm; p < 0.001) and mid-lingual (MD = 0.62 mm; p = 0.05) resorption. Part of the bone resorption in the spontaneous healing group was compensated by soft-tissues, since the observed differences between groups in linear ridge reduction evaluated through cast models superimposition were smaller (MD = 0.52 mm; p < 0.001). CONCLUSIONS: Alveolar ridge preservation with xenogeneic bone substitutes and non-autogenous resorbable socket sealing materials is efficacious in reducing post-extraction bone and ridge changes in the esthetic region.

Bacterial cellulose matrix and acellular dermal matrix seeded with fibroblasts grown in platelet-rich plasma supplemented medium, compared to free gingival grafts: a randomized animal study.

PURPOSE: Mucogingival defects (MGDs), such as dental root recessions, decreased vestibular depth, and absence of keratinized tissues, are commonly seen in dental clinics. MGDs may result in functional, aesthetic, and hygienic concerns. In these situations, autogenous soft tissue grafts are considered the gold-standard treatment. This study compares the healing process of free gingival grafts (FGGs) to bacterial cellulose matrix (BCM) and human acellular dermal matrix (ADM) seeded with fibroblasts from culture supplemented with platelet-rich plasma in a rat model. METHODS: Surgical defects were made in rats, which received the following treatments in a randomized manner: group I, negative control (defect creation only); group II, positive control (FGG); group III, BCM; group IV, BCM + fibroblasts; group V, ADM; and group VI, ADM + fibroblasts. Clinical, histological, and immunological analyses were performed 15 days after grafting. Clinical examinations recorded epithelium regularity and the presence of ulcers, erythema, and/or edema. RESULTS: The histological analysis revealed the degree of reepithelization, width, regularity, and presence of keratin. The Fisher exact statistical test was applied to the results (P<0.05). No groups showed ulcers except for group I. All groups had regular epithelium without erythema and without edema. Histologically, all groups exhibited regular epithelium with keratinization, and myofibroblasts were present in the connective tissue. The groups that received engineered grafts showed similar clinical and histological results to the FGG group. CONCLUSIONS: Within the limitations of this study, it was concluded that BCM and ADM can be used as cell scaffolds, with ADM yielding the best results. This study supports the use of this technical protocol in humans.

Bibliometric analysis of the 100 most cited articles on bone grafting in dentistry.

AIM: This bibliometric study analyzed the characteristics of the 100 most cited articles on bone grafts in dentistry. MATERIALS AND METHODS: A database search was performed on the Web of Science Core Collection using a specific search strategy. Scopus and Google Scholar were also consulted for citation comparisons. Data extracted included: title, citation metrics, publication year, journal, study design, graft material, surgical technique, authors, institution, and country. Bibliometric networks were generated using VOSviewer. RESULTS: The identified articles were published between 1991 and 2019. Citation counts ranged from 120 to 1161 (mean: 240, 30). Clinical Oral Implants Research was the most cited journal (5175 citations; 25/100). Xenogeneic bone graft material was the most frequently used (5130 citations; 22/100). Europe had 62 articles (14,604 citations), and the United States was the most prominent country (5209 citations; 22/100). The University of Bern had the highest number of citations (2565 citations; 13/100), with Buser D as the author with the largest number of articles (2648 citations; 12/100). CONCLUSION: This study shows the scientific progress on bone grafts in dentistry. The use of xenogeneic grafts for horizontal and/or vertical ridge augmentation was the most prominent trend.

Polydioxanone Dome Technique for Guided Bone Regeneration: Surgical Technique and Results up to 72 Months of Follow-up.

This study aimed to describe the step-by-step procedure of the polydioxanone dome technique associated with guided bone regeneration (GBR) and to report the results up to 72 months after implant loading. Patients with maxillary horizontal bone defects (< 5 mm residual width, confirmed by CBCT scan) were treated with the proposed intervention. During the GBR procedure, four bone perforations were strategically prepared in a roughly square configuration. Segments of polydioxanone suture material were introduced in the perforations, forming a dome-shaped structure. Six months after bone augmentation, a new CBCT was performed. After implant restoration, periapical radiographs were taken, which were then repeated annually. The following outcomes were analyzed: implant survival, horizontal bone gain, marginal bone level, and complications. Twenty implants were placed in 11 patients with a survival rate of 100% in a mean follow-up of 38.18 ± 19.65 months after loading. Mean horizontal bone gain was 3.82 ± 1.67 mm and mean marginal bone level was -0.12 ± 1.17 mm. Only minor complications were observed. The present results suggest that the polydioxanone dome technique may represent a promising approach during horizontal GBR, alone or in combination with implant placement. Int J Periodontics Restorative Dent 2023;43:223-230. doi: 10.11607/prd.6087.

Histologic and Histomorphometric Analyses of Free Gingival Grafts After Mechanical Expansion: A Study in Dogs.

This study assessed the histologic and histomorphometric changes of free gingival grafts in a canine model after mechanical expansion. A total of eight epithelialized tissue samples were obtained from the palate of eight Beagle dogs. Samples were cut in half and separated into two groups: the test group, in which a device was used to expand the grafts, and the control group, without expansion. After histologic processing, samples were evaluated by qualitative histology and histomorphometry. Histologic analysis revealed some differences in epithelial cell morphology and keratin layer integrity in the test group compared to the control group. Differences in histomorphometric parameters for the expanded and nonexpanded groups, including the thickness of the keratin layer (15.4 ± 13.4 µm and 32.3 ± 18.1 µm, respectively), thickness of the epithelium (398.0 ± 168.0 µm and 368.4 ± 142.8 µm, respectively), and the area occupied by collagen fibers in the connective tissue (62.0% ± 11.0% and 55.8% ± 7.6%, respectively), were not statistically significant (P < .05). Despite some changes in qualitative histology, free gingival grafts maintained their histomorphometric characteristics after mechanical expansion. These data provide a scientific basis for the use of mechanical expansion as a possible procedure to reduce the morbidity of autogenous grafts because a single soft tissue sample can be expanded before grafting. Int J Periodontics Restorative Dent 2023;43:e89-e97. doi: 10.11607/prd.5752.

Functionalization of a Volume-Stable Collagen Matrix Using Liquid Platelet-Rich Fibrin: A Case Report Presenting a New Approach for Root Coverage.

This case report presents a novel approach for root coverage of multiple gingival recessions with a volume-stable collagen matrix functionalized with injectable platelet-rich fibrin (i-PRF). A patient with multiple gingival recessions in the anterior maxilla was submitted to root coverage by coronally advanced flap with split-full-split incisions. Blood collection was performed before surgery and i-PRF was obtained after centrifugation (relative centrifugal force (RCF) 400 g, 2700 rpm, 3 minutes). A volume-stable collagen matrix was soaked with i-PRF and applied as a substitute for autogenous connective tissue graft. A mean root coverage of 83% was observed after a 12-month follow-up period, and only slight modifications were detected in a 30-month follow-up consultation. The association of a volume-stable collagen matrix with i-PRF successfully treated multiple gingival recessions with reduced morbidity since a connective tissue collection was avoided.

Tomographic and Histologic Analysis of Different Socket Sealing Approaches for Alveolar Ridge Preservation: A Randomized Controlled Pilot Clinical Trial.

Purpose: To compare different socket sealing approaches for alveolar ridge preservation and assess the dimensional changes and histologic characteristics of soft and hard tissues in a 4- to 6-month period. Material and Methods: A total of 22 patients with indicated single-tooth extraction in the maxillary nonmolar region were eligible for this study. After CBCT scanning and minimally traumatic tooth extraction, the alveolar sockets were filled with demineralized bovine bone mineral with collagen (DBBM-C) in patients from all groups except for those in the control group. Patients were divided into groups for socket sealing as follows: unsealed/spontaneous healing (control; n = 6), collagen matrix (n = 5), collagen membrane (n = 5), and autogenous graft (n = 6). A second CBCT scan was taken 4 to 6 months after extraction, and a trephine biopsy of soft and hard tissues was collected during implant placement. Tomographic dimensional changes were compared between groups. Intragroup tomographic evaluation and histological analysis were also performed. Results: Analysis of dimensional changes did not detect differences between the socket sealing groups (P > .05). In an intragroup evaluation, the height of the buccal bone and cross-sectional area of the alveolar ridge were significantly lower 4 to 6 months after extraction for the control group (P = .031). Histological analysis revealed that the socket sealing approach had no impact on hard and soft tissue formation. Conclusion: The data from the present study suggest that socket sealing with a collagen matrix, a collagen membrane exposed to the oral cavity, or an autogenous punch graft had no difference in the effects on volumetric maintenance and tissue formation in a period of 4 to 6 months.

Impact of a Static Magnetic Field on Early Osseointegration: A Pilot Study in Canines.

A static magnetic field generated by neodymium-iron-boron (NdFeB) magnets placed in the inner cavity of dental implants can enhance bone regeneration in rabbits. It is, however, unknown whether static magnetic fields support osseointegration in a canine model. We therefore determined the potential osteogenic effect of implants carrying NdFeB magnets inserted in the tibia of six adult canines in the early stages of osseointegration. Here, we report that after 15 days of healing, magnetic and regular implants showed a high variation with a median new bone-to-implant contact (nBIC) in the cortical (41.3% and 7.3%) and the medullary (28.6% and 44.8%) region, respectively. Consistently, the median new bone volume/tissue volume (nBV/TV) in the cortical (14.9% and 5.4%) and the medullary (22.2% and 22.4%) region were not significantly different. One week of healing only resulted in negligible bone formation. These findings suggest that considering the large variation and the pilot nature of this study, magnetic implants failed to support peri-implant bone formation in a canine model.

Dimensional Influence of Epithelialized Tissue Graft Harvested From Palate on Postoperative Pain: a Systematic Review.

Objectives: The aim of the present systematic review was to evaluate the dimensional influence of the epithelialized tissue graft harvested from the palate in the postoperative pain. Material and Methods: Research was conducted in electronic databases Cochrane Library, Embase, LILACS, PubMed, Scopus, and Web of Science upwards May 15, 2022. Studies that reported the influence of graft dimensions of palatal epithelized harvesting on postoperative pain were eligible. The evaluation was made using the methodological quality assessment by Joanna Briggs Institute Critical Appraisal Checklist for randomized clinical trials and non-randomized studies and the level of evidence according to GRADE. Results: Four studies were included. The clinical and methodological heterogeneity among studies led to an analysed narrative. The postoperative pain was assessed during the period of 1 to 28 postoperative days. It was determined by using visual analog scale in three studies, while the evaluation was performed indirectly based on analgesics intake in one study. According to three studies, bigger graft sizes were associated with higher postoperative pain. The methodological quality assessment categorized two study as high (one randomized control trial and one non-randomized), and two as moderate (one randomized control trial and one non-randomized). The data was considered moderate. Conclusions: Based on the moderate certainty level, bigger graft sizes of palatal epithelized harvesting appear to promote more postoperative pain. Understanding the postoperative pain as a response to a graft extension may assist some clinical decisions regarding the surgical periodontal and peri-implant planning.

Analysis of the Viability and Morphology of Gingival Cells on Materials Used in Novel Prosthetic Components: In Vitro Study.

AIM: The objective of this in vitro study was to evaluate the viability and morphology of human fibroblasts and keratinocytes cells, both grown on stainless steel (steel) (18Cr14Ni2.5Mo), and polyether-ether-ketone (PEEK) surfaces, hypothesizing the use of these surfaces as novel materials for prosthetic components. MATERIALS AND METHODS: Gingival human keratinocytes and gingival human fibroblasts lines were grown on discs made by steel (n = 36), PEEK (n = 36), and titanium (Ti) (Ti6A14V) (n = 36)-control. For viability assay, cultures were grown at 24 hours (TV1), 48 hours (TV2), and 72 hours (TV3) times and evaluated by the colorimetric tetrazolium assay (MTT). For morphology and cell adhesion assays, after 24 hours (TM1), 48 hours (TM2), and 96 hours (TM3) of cell culture, cells were examined by scanning electron microscopy (SEM) and analyzed at magnifications with 500×, 1,000×, and 2,500×. RESULTS: Regarding the viability, the keratinocytes did not present statistical difference on the different materials, in TV1 and TV3 times of culture. Their growth rate increased on all materials, being more expressive in steel; the fibroblasts did not present statistical difference on the different materials, in TV2 and TV3 times of culture. The growth rate of these decreased on all materials, being more expressive in PEEK. The morphology analyses show increase in cell numbers, adequate spreading, and adhesion at all cultivation times (TM1, TM2, and TM3) in both cell lines, on all materials. CONCLUSION: All materials tested are suitable for use in the manufacture of prosthetic components for implant-supported rehabilitations, considering the limitations of this study. CLINICAL SIGNIFICANCE: This work analyzes the cellular response of cells present in the human gingiva, as a way to simulate the peri-implant tissue response around novel angular prosthetic components made of stainless steel and PEEK.

Challenging replacement of a maxillary canine with an implant-supported restoration: A surgical and prosthetic approach.

This clinical report describes the replacement of a traumatized maxillary canine that was extracted after unsuccessful orthodontic extrusion with an implant-supported restoration. Guided bone regeneration surgery was performed, followed by a second surgery with implant placement plus simultaneous bone and tissue regeneration. Esthetics and function were achieved with the placement of a veneered zirconia implant-supported restoration.

Effect of dexamethasone as osteogenic supplementation in in vitro osteogenic differentiation of stem cells from human exfoliated deciduous teeth.

In in vitro culture systems, dexamethasone (DEX) has been applied with ascorbic acid (ASC) and ß-glycerophosphate (ßGLY) as culture media supplementation to induce osteogenic differentiation of mesenchymal stem cells. However, there are some inconsistencies regarding the role of DEX as osteogenic media supplementation. Therefore, this study verified the influence of DEX culture media supplementation on the osteogenic differentiation, especially the capacity to mineralize the extracellular matrix of stem cells from human exfoliated deciduous teeth (SHED). Five groups were established: G1-SHED + Dulbecco's Modified Eagles' Medium (DMEM) + fetal bovine serum (FBS); G2-SHED + DMEM + FBS + DEX; G3-SHED + DMEM + FBS + ASC + ßGLY; G4-SHED + DMEM + FBS + ASC + ßGLY + DEX; G5-MC3T3-E1 + α Minimal Essential Medium (MEM) + FBS + ASC + ßGLY. DNA content, alkaline phosphatase (ALP) activity, free calcium quantification in the extracellular medium, and extracellular matrix mineralization quantification through staining with von Kossa, alizarin red, and tetracycline were performed on days 7 and 21. Osteogenic media supplemented with ASC and ß-GLY demonstrated similar effects on SHED in the presence or absence of DEX for DNA content (day 21) and capacity to mineralize the extracellular matrix according to alizarin red and tetracycline quantifications (day 21). In addition, the presence of DEX in the osteogenic medium promoted less ALP activity (day 7) and extracellular matrix mineralization according to the von Kossa assay (day 21), and more free calcium quantification at extracellular medium (day 21). In summary, the presence of DEX in the osteogenic media supplementation did not interfere with SHED commitment into mineral matrix depositor cells. We suggest that DEX may be omitted from culture media supplementation for SHED osteogenic differentiation in vitro studies.

Histologic and histomorphometric analysis of two biomaterials of xenogenous origin for maxillary sinus elevation: a clinical study.

Objective: This study analyzed two xenogenous biomaterials based on deproteinized bovine bone mineral applied for maxillary sinus elevation. Method and materials: Fourteen patients were submitted to maxillary sinus augmentation with one of the following biomaterials: Criteria Lumina Bone Porous (test group) or Geistlich Bio-Oss (control group), both of large granules (1 to 2 mm). After 6 months, trephine biopsies were collected at the time of implant placement: 27 samples (11 patients) in the test group; 7 samples (3 patients) in the control group. Biopsies were analyzed by descriptive histology and histomorphometry, in which the percentages of newly formed bone, residual biomaterial particles, and connective tissue were evaluated. Results: Histomorphometry showed means for test and control groups, respectively, of 32.41% ± 9.42% and 26.59% ± 4.88% for newly formed bone, 22.89% ± 4.58% and 25.00% ± 4.81% for residual biomaterial, and 44.70% ± 9.54% and 48.41% ± 3.36% for connective tissue. There were no differences between groups (P > .05). Conclusion: This study concluded that Criteria Lumina Bone Porous presented similar histologic and histomorphometric characteristics to Geistlich Bio-Oss 6 months after sinus elevation surgery, identifying the tested biomaterial as an interesting alternative for bone augmentation in the maxillary sinus.

Effect of cyanoacrylate tissue adhesive in postoperative palatal pain management: a systematic review.

OBJECTIVE: To critically appraise available literature concerning the effect of cyanoacrylate tissue adhesive (CTA) in postoperative palatal pain management. MATERIALS AND METHODS: Electronic databases (Cochrane, PubMed, LILACS, Scopus, and Web of Science) were searched, complemented with grey literature databases up to June 2020. Studies reporting the effect of cyanoacrylate tissue adhesive compared to any other methods in postoperative palatal pain management were considered eligible. The risk of bias among and across included studies was assessed. RESULTS: Finally, four studies were considered eligible. Regarding free gingival graft (FGG), cyanoacrylate tissue adhesive with hemostatic sponge promoted less postoperative pain (PP) and analgesic consumption (AC). Also, cyanoacrylate tissue adhesive with platelet-rich fibrin produced less PP and more wound healing at the palatal area than cyanoacrylate tissue adhesive and wet gauze. Additionally, cyanoacrylate tissue adhesive promoted less PP and AC than wet gauze and suture. Concerning connective tissue graft (CTG), cyanoacrylate tissue adhesive, and suture produced similar PP, AC, and willingness for retreatment. CONCLUSIONS: Based on the low certainty level, cyanoacrylate tissue adhesive appears to promote less PP and AC than wet gauze and suture regarding FGG. Additionally, cyanoacrylate tissue adhesive appears to increase the effect of hemostatic sponge, contributing to the reduction of PP and AC. Regarding CTG, cyanoacrylate tissue adhesive appears to promote similar PP, AC, and willingness for retreatment than the suture. Therefore, cyanoacrylate tissue adhesive has shown promising usefulness for PP management in FGG, but not a clear benefit for CTG. CLINICAL RELEVANCE: The adoption of different agents for the protection of the palatal donor site following gingival harvesting procedures may provide better comfort to the patient.

Early Biofilm Formation on Rough and Smooth Titanium Specimens: a Systematic Review of Clinical Studies.

OBJECTIVES: There is a concern whether the enhancement on implant surface roughness is responsible for higher biofilm formation, which acts as an aetiological factor for peri-implant diseases. The aim of the present systematic review was to answer the following question: "Are rough surfaces more susceptible to early biofilm formation when compared to smoother surfaces on titanium specimens?". MATERIAL AND METHODS: The research was performed on PubMed, Web of Science and Scopus, up to August 2021. Eligibility criteria included studies that analysed human biofilm formation on titanium specimens with distinct surface roughness (smooth vs minimally, moderate, or rough) over the experimental times of 1 or 3 days. Roughness average (Ra) and biofilm analysis parameters were extracted from selected articles. Risk of bias was evaluated using the Checklist for Quasi-Experimental Studies. RESULTS: Of 5286 papers, 5 were included and analysed. Smooth titanium surfaces included machined and anodized titanium/Ti-6Al-4V; machined and acid etched TiZr. Minimally, moderately, or rough surfaces comprised titanium and titanium alloys (TiZr, Ti-6Al-4V), that received surface treatments (anodization, acid-etching, blasting, hydroxyapatite-coating). No statistically significant difference on biofilm formation on rough and smooth titanium surfaces was reported by 3 studies, while more contamination on rough titanium surfaces was stated by 2 investigations. An isolated smooth surface has also been associated to higher contamination. Moderate to high quality methodological assessment of studies were identified. CONCLUSIONS: It is not possible to assume that rough surfaces are more susceptible to early biofilm formation than smooth titanium surfaces. Additional studies are required to study this multifarious interaction.

Strategies to Reduce Biofilm Formation in PEEK Materials Applied to Implant Dentistry-A Comprehensive Review.

Polyether-ether-ketone (PEEK) has emerged in Implant Dentistry with a series of short-time applications and as a promising material to substitute definitive dental implants. Several strategies have been investigated to diminish biofilm formation on the PEEK surface aiming to decrease the possibility of related infections. Therefore, a comprehensive review was carried out in order to compare PEEK with materials widely used nowadays in Implant Dentistry, such as titanium and zirconia, placing emphasis on studies investigating its ability to grant or prevent biofilm formation. Most studies failed to reveal significant antimicrobial activity in pure PEEK, while several studies described new strategies to reduce biofilm formation and bacterial colonization on this material. Those include the PEEK sulfonation process, incorporation of therapeutic and bioactive agents in PEEK matrix or on PEEK surface, PEEK coatings and incorporation of reinforcement agents, in order to produce nanocomposites or blends. The two most analyzed surface properties were contact angle and roughness, while the most studied bacteria were Escherichia coli and Staphylococcus aureus. Despite PEEK's susceptibility to biofilm formation, a great number of strategies discussed in this study were able to improve its antibiofilm and antimicrobial properties.

Biomarkers in biological fluids in adults with periodontitis and/or obesity: A meta-analysis.

Obesity and periodontal diseases have been investigated to be interconnected, but the molecular mechanism underlying this association is still not clear. The aim of this systematic review is to assess the association of serum, salivary and gingival crevicular fluid (GCF) inflammatory markers (IMs), obesity, and periodontitis. Studies that evaluated IM of adults according to obesity status (O) and periodontitis status (P) (O+P+; O-P+; O+P-) were screened on several electronic databases and grey literature up until February 2019. Risk of bias assessment and level of evidence were evaluated through Fowkes and Fulton scale and Grading of Recommendations Assessment, Development and Evaluation (GRADE). Meta-analyses were grouped according to the biological matrix studied (serum/GCF) and groups (O+P+ vs. O-P+/O+P+ vs. O+P-). Out of the 832 studies screened, 21 were considered in qualitative synthesis and 15 in quantitative synthesis (meta-analysis). Although included studies showed mostly "no" or "minor" problems during the quality assessment, GRADE assessment indicated very low to moderate level of evidence based on the question answered. O+P+ adults exhibited significantly higher serum levels of C-reactive protein (CRP), interleukin 6 (IL-6), leptin, and tumor necrosis factor-α (TNF-alpha) and higher resistin GCF levels than O-P+. O+P+ adults showed significantly higher serum levels of IL-6 and leptin and lower adiponectin serum levels than O+P-. Only qualitative information could be obtained of the IM vaspin, omentin-1, chemerin, IL-10, progranulin, MCP-4, IL-1ß, and interferon-γ (IFN-γ). Obesity and periodontitis, together or separately, are associated with altered serum and GCF levels of CRP, IL-6, leptin, TNF-alpha, adiponectin, and resistin. It was not possible to evaluate the association between obesity and periodontitis at salivary levels. The role of recently investigated biomarkers as vaspin, omentin-1, chemerin, IL-10, progranulin, MCP-4, IL-1ß, and IFN-γ, which can be key points underlying the association between obesity and periodontitis, remains to be further investigated.

Effects of Short-Chain Fatty Acids on Human Oral Epithelial Cells and the Potential Impact on Periodontal Disease: A Systematic Review of In Vitro Studies.

Short-chain fatty acids (SCFA), bacterial metabolites released from dental biofilm, are supposed to target the oral epithelium. There is, however, no consensus on how SCFA affect the oral epithelial cells. The objective of the present study was to systematically review the available in vitro evidence of the impact of SCFA on human oral epithelial cells in the context of periodontal disease. A comprehensive electronic search using five databases along with a grey literature search was performed. In vitro studies that evaluated the effects of SCFA on human oral epithelial cells were eligible for inclusion. Risk of bias was assessed by the University of Bristol's tool for assessing risk of bias in cell culture studies. Certainty in cumulative evidence was evaluated using GRADE criteria (grading of recommendations assessment, development, and evaluation). Of 3591 records identified, 10 were eligible for inclusion. A meta-analysis was not possible due to the heterogeneity between the studies. The risk of bias across the studies was considered "serious" due to the presence of methodological biases. Despite these limitations, this review showed that SCFA negatively affect the viability of oral epithelial cells by activating a series of cellular events that includes apoptosis, autophagy, and pyroptosis. SCFA impair the integrity and presumably the transmigration of leucocytes through the epithelial layer by changing junctional and adhesion protein expression, respectively. SCFA also affect the expression of chemokines and cytokines in oral epithelial cells. Future research needs to identify the underlying signaling cascades and to translate the in vitro findings into preclinical models.